ZhongMianAdmin/docs/libs/codemirror/codemirror.js

// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

// This is CodeMirror (https://codemirror.net), a code editor
// implemented in JavaScript on top of the browser's DOM.
//
// You can find some technical background for some of the code below
// at http://marijnhaverbeke.nl/blog/#cm-internals .

;(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined'
        ? (module.exports = factory())
        : typeof define === 'function' && define.amd
        ? define(factory)
        : ((global = global || self), (global.CodeMirror = factory()))
})(this, function () {
    'use strict'

    // Kludges for bugs and behavior differences that can't be feature
    // detected are enabled based on userAgent etc sniffing.
    var userAgent = navigator.userAgent
    var platform = navigator.platform

    var gecko = /gecko\/\d/i.test(userAgent)
    var ie_upto10 = /MSIE \d/.test(userAgent)
    var ie_11up = /Trident\/(?:[7-9]|\d{2,})\..*rv:(\d+)/.exec(userAgent)
    var edge = /Edge\/(\d+)/.exec(userAgent)
    var ie = ie_upto10 || ie_11up || edge
    var ie_version = ie && (ie_upto10 ? document.documentMode || 6 : +(edge || ie_11up)[1])
    var webkit = !edge && /WebKit\//.test(userAgent)
    var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(userAgent)
    var chrome = !edge && /Chrome\//.test(userAgent)
    var presto = /Opera\//.test(userAgent)
    var safari = /Apple Computer/.test(navigator.vendor)
    var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(userAgent)
    var phantom = /PhantomJS/.test(userAgent)

    var ios = safari && (/Mobile\/\w+/.test(userAgent) || navigator.maxTouchPoints > 2)
    var android = /Android/.test(userAgent)
    // This is woefully incomplete. Suggestions for alternative methods welcome.
    var mobile = ios || android || /webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(userAgent)
    var mac = ios || /Mac/.test(platform)
    var chromeOS = /\bCrOS\b/.test(userAgent)
    var windows = /win/i.test(platform)

    var presto_version = presto && userAgent.match(/Version\/(\d*\.\d*)/)
    if (presto_version) {
        presto_version = Number(presto_version[1])
    }
    if (presto_version && presto_version >= 15) {
        presto = false
        webkit = true
    }
    // Some browsers use the wrong event properties to signal cmd/ctrl on OS X
    var flipCtrlCmd = mac && (qtwebkit || (presto && (presto_version == null || presto_version < 12.11)))
    var captureRightClick = gecko || (ie && ie_version >= 9)

    function classTest(cls) {
        return new RegExp('(^|\\s)' + cls + '(?:$|\\s)\\s*')
    }

    var rmClass = function (node, cls) {
        var current = node.className
        var match = classTest(cls).exec(current)
        if (match) {
            var after = current.slice(match.index + match[0].length)
            node.className = current.slice(0, match.index) + (after ? match[1] + after : '')
        }
    }

    function removeChildren(e) {
        for (var count = e.childNodes.length; count > 0; --count) {
            e.removeChild(e.firstChild)
        }
        return e
    }

    function removeChildrenAndAdd(parent, e) {
        return removeChildren(parent).appendChild(e)
    }

    function elt(tag, content, className, style) {
        var e = document.createElement(tag)
        if (className) {
            e.className = className
        }
        if (style) {
            e.style.cssText = style
        }
        if (typeof content == 'string') {
            e.appendChild(document.createTextNode(content))
        } else if (content) {
            for (var i = 0; i < content.length; ++i) {
                e.appendChild(content[i])
            }
        }
        return e
    }
    // wrapper for elt, which removes the elt from the accessibility tree
    function eltP(tag, content, className, style) {
        var e = elt(tag, content, className, style)
        e.setAttribute('role', 'presentation')
        return e
    }

    var range
    if (document.createRange) {
        range = function (node, start, end, endNode) {
            var r = document.createRange()
            r.setEnd(endNode || node, end)
            r.setStart(node, start)
            return r
        }
    } else {
        range = function (node, start, end) {
            var r = document.body.createTextRange()
            try {
                r.moveToElementText(node.parentNode)
            } catch (e) {
                return r
            }
            r.collapse(true)
            r.moveEnd('character', end)
            r.moveStart('character', start)
            return r
        }
    }

    function contains(parent, child) {
        if (child.nodeType == 3) {
            // Android browser always returns false when child is a textnode
            child = child.parentNode
        }
        if (parent.contains) {
            return parent.contains(child)
        }
        do {
            if (child.nodeType == 11) {
                child = child.host
            }
            if (child == parent) {
                return true
            }
        } while ((child = child.parentNode))
    }

    function activeElt() {
        // IE and Edge may throw an "Unspecified Error" when accessing document.activeElement.
        // IE < 10 will throw when accessed while the page is loading or in an iframe.
        // IE > 9 and Edge will throw when accessed in an iframe if document.body is unavailable.
        var activeElement
        try {
            activeElement = document.activeElement
        } catch (e) {
            activeElement = document.body || null
        }
        while (activeElement && activeElement.shadowRoot && activeElement.shadowRoot.activeElement) {
            activeElement = activeElement.shadowRoot.activeElement
        }
        return activeElement
    }

    function addClass(node, cls) {
        var current = node.className
        if (!classTest(cls).test(current)) {
            node.className += (current ? ' ' : '') + cls
        }
    }
    function joinClasses(a, b) {
        var as = a.split(' ')
        for (var i = 0; i < as.length; i++) {
            if (as[i] && !classTest(as[i]).test(b)) {
                b += ' ' + as[i]
            }
        }
        return b
    }

    var selectInput = function (node) {
        node.select()
    }
    if (ios) {
        // Mobile Safari apparently has a bug where select() is broken.
        selectInput = function (node) {
            node.selectionStart = 0
            node.selectionEnd = node.value.length
        }
    } else if (ie) {
        // Suppress mysterious IE10 errors
        selectInput = function (node) {
            try {
                node.select()
            } catch (_e) {}
        }
    }

    function bind(f) {
        var args = Array.prototype.slice.call(arguments, 1)
        return function () {
            return f.apply(null, args)
        }
    }

    function copyObj(obj, target, overwrite) {
        if (!target) {
            target = {}
        }
        for (var prop in obj) {
            if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop))) {
                target[prop] = obj[prop]
            }
        }
        return target
    }

    // Counts the column offset in a string, taking tabs into account.
    // Used mostly to find indentation.
    function countColumn(string, end, tabSize, startIndex, startValue) {
        if (end == null) {
            end = string.search(/[^\s\u00a0]/)
            if (end == -1) {
                end = string.length
            }
        }
        for (var i = startIndex || 0, n = startValue || 0; ; ) {
            var nextTab = string.indexOf('\t', i)
            if (nextTab < 0 || nextTab >= end) {
                return n + (end - i)
            }
            n += nextTab - i
            n += tabSize - (n % tabSize)
            i = nextTab + 1
        }
    }

    var Delayed = function () {
        this.id = null
        this.f = null
        this.time = 0
        this.handler = bind(this.onTimeout, this)
    }
    Delayed.prototype.onTimeout = function (self) {
        self.id = 0
        if (self.time <= +new Date()) {
            self.f()
        } else {
            setTimeout(self.handler, self.time - +new Date())
        }
    }
    Delayed.prototype.set = function (ms, f) {
        this.f = f
        var time = +new Date() + ms
        if (!this.id || time < this.time) {
            clearTimeout(this.id)
            this.id = setTimeout(this.handler, ms)
            this.time = time
        }
    }

    function indexOf(array, elt) {
        for (var i = 0; i < array.length; ++i) {
            if (array[i] == elt) {
                return i
            }
        }
        return -1
    }

    // Number of pixels added to scroller and sizer to hide scrollbar
    var scrollerGap = 50

    // Returned or thrown by various protocols to signal 'I'm not
    // handling this'.
    var Pass = {
        toString: function () {
            return 'CodeMirror.Pass'
        },
    }

    // Reused option objects for setSelection & friends
    var sel_dontScroll = { scroll: false },
        sel_mouse = { origin: '*mouse' },
        sel_move = { origin: '+move' }

    // The inverse of countColumn -- find the offset that corresponds to
    // a particular column.
    function findColumn(string, goal, tabSize) {
        for (var pos = 0, col = 0; ; ) {
            var nextTab = string.indexOf('\t', pos)
            if (nextTab == -1) {
                nextTab = string.length
            }
            var skipped = nextTab - pos
            if (nextTab == string.length || col + skipped >= goal) {
                return pos + Math.min(skipped, goal - col)
            }
            col += nextTab - pos
            col += tabSize - (col % tabSize)
            pos = nextTab + 1
            if (col >= goal) {
                return pos
            }
        }
    }

    var spaceStrs = ['']
    function spaceStr(n) {
        while (spaceStrs.length <= n) {
            spaceStrs.push(lst(spaceStrs) + ' ')
        }
        return spaceStrs[n]
    }

    function lst(arr) {
        return arr[arr.length - 1]
    }

    function map(array, f) {
        var out = []
        for (var i = 0; i < array.length; i++) {
            out[i] = f(array[i], i)
        }
        return out
    }

    function insertSorted(array, value, score) {
        var pos = 0,
            priority = score(value)
        while (pos < array.length && score(array[pos]) <= priority) {
            pos++
        }
        array.splice(pos, 0, value)
    }

    function nothing() {}

    function createObj(base, props) {
        var inst
        if (Object.create) {
            inst = Object.create(base)
        } else {
            nothing.prototype = base
            inst = new nothing()
        }
        if (props) {
            copyObj(props, inst)
        }
        return inst
    }

    var nonASCIISingleCaseWordChar = /[\u00df\u0587\u0590-\u05f4\u0600-\u06ff\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/
    function isWordCharBasic(ch) {
        return /\w/.test(ch) || (ch > '\x80' && (ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch)))
    }
    function isWordChar(ch, helper) {
        if (!helper) {
            return isWordCharBasic(ch)
        }
        if (helper.source.indexOf('\\w') > -1 && isWordCharBasic(ch)) {
            return true
        }
        return helper.test(ch)
    }

    function isEmpty(obj) {
        for (var n in obj) {
            if (obj.hasOwnProperty(n) && obj[n]) {
                return false
            }
        }
        return true
    }

    // Extending unicode characters. A series of a non-extending char +
    // any number of extending chars is treated as a single unit as far
    // as editing and measuring is concerned. This is not fully correct,
    // since some scripts/fonts/browsers also treat other configurations
    // of code points as a group.
    var extendingChars =
        /[\u0300-\u036f\u0483-\u0489\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u065e\u0670\u06d6-\u06dc\u06de-\u06e4\u06e7\u06e8\u06ea-\u06ed\u0711\u0730-\u074a\u07a6-\u07b0\u07eb-\u07f3\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0900-\u0902\u093c\u0941-\u0948\u094d\u0951-\u0955\u0962\u0963\u0981\u09bc\u09be\u09c1-\u09c4\u09cd\u09d7\u09e2\u09e3\u0a01\u0a02\u0a3c\u0a41\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a70\u0a71\u0a75\u0a81\u0a82\u0abc\u0ac1-\u0ac5\u0ac7\u0ac8\u0acd\u0ae2\u0ae3\u0b01\u0b3c\u0b3e\u0b3f\u0b41-\u0b44\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b82\u0bbe\u0bc0\u0bcd\u0bd7\u0c3e-\u0c40\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0cbc\u0cbf\u0cc2\u0cc6\u0ccc\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0d3e\u0d41-\u0d44\u0d4d\u0d57\u0d62\u0d63\u0dca\u0dcf\u0dd2-\u0dd4\u0dd6\u0ddf\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1\u0eb4-\u0eb9\u0ebb\u0ebc\u0ec8-\u0ecd\u0f18\u0f19\u0f35\u0f37\u0f39\u0f71-\u0f7e\u0f80-\u0f84\u0f86\u0f87\u0f90-\u0f97\u0f99-\u0fbc\u0fc6\u102d-\u1030\u1032-\u1037\u1039\u103a\u103d\u103e\u1058\u1059\u105e-\u1060\u1071-\u1074\u1082\u1085\u1086\u108d\u109d\u135f\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b7-\u17bd\u17c6\u17c9-\u17d3\u17dd\u180b-\u180d\u18a9\u1920-\u1922\u1927\u1928\u1932\u1939-\u193b\u1a17\u1a18\u1a56\u1a58-\u1a5e\u1a60\u1a62\u1a65-\u1a6c\u1a73-\u1a7c\u1a7f\u1b00-\u1b03\u1b34\u1b36-\u1b3a\u1b3c\u1b42\u1b6b-\u1b73\u1b80\u1b81\u1ba2-\u1ba5\u1ba8\u1ba9\u1c2c-\u1c33\u1c36\u1c37\u1cd0-\u1cd2\u1cd4-\u1ce0\u1ce2-\u1ce8\u1ced\u1dc0-\u1de6\u1dfd-\u1dff\u200c\u200d\u20d0-\u20f0\u2cef-\u2cf1\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua66f-\ua672\ua67c\ua67d\ua6f0\ua6f1\ua802\ua806\ua80b\ua825\ua826\ua8c4\ua8e0-\ua8f1\ua926-\ua92d\ua947-\ua951\ua980-\ua982\ua9b3\ua9b6-\ua9b9\ua9bc\uaa29-\uaa2e\uaa31\uaa32\uaa35\uaa36\uaa43\uaa4c\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uabe5\uabe8\uabed\udc00-\udfff\ufb1e\ufe00-\ufe0f\ufe20-\ufe26\uff9e\uff9f]/
    function isExtendingChar(ch) {
        return ch.charCodeAt(0) >= 768 && extendingChars.test(ch)
    }

    // Returns a number from the range [`0`; `str.length`] unless `pos` is outside that range.
    function skipExtendingChars(str, pos, dir) {
        while ((dir < 0 ? pos > 0 : pos < str.length) && isExtendingChar(str.charAt(pos))) {
            pos += dir
        }
        return pos
    }

    // Returns the value from the range [`from`; `to`] that satisfies
    // `pred` and is closest to `from`. Assumes that at least `to`
    // satisfies `pred`. Supports `from` being greater than `to`.
    function findFirst(pred, from, to) {
        // At any point we are certain `to` satisfies `pred`, don't know
        // whether `from` does.
        var dir = from > to ? -1 : 1
        for (;;) {
            if (from == to) {
                return from
            }
            var midF = (from + to) / 2,
                mid = dir < 0 ? Math.ceil(midF) : Math.floor(midF)
            if (mid == from) {
                return pred(mid) ? from : to
            }
            if (pred(mid)) {
                to = mid
            } else {
                from = mid + dir
            }
        }
    }

    // BIDI HELPERS

    function iterateBidiSections(order, from, to, f) {
        if (!order) {
            return f(from, to, 'ltr', 0)
        }
        var found = false
        for (var i = 0; i < order.length; ++i) {
            var part = order[i]
            if ((part.from < to && part.to > from) || (from == to && part.to == from)) {
                f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? 'rtl' : 'ltr', i)
                found = true
            }
        }
        if (!found) {
            f(from, to, 'ltr')
        }
    }

    var bidiOther = null
    function getBidiPartAt(order, ch, sticky) {
        var found
        bidiOther = null
        for (var i = 0; i < order.length; ++i) {
            var cur = order[i]
            if (cur.from < ch && cur.to > ch) {
                return i
            }
            if (cur.to == ch) {
                if (cur.from != cur.to && sticky == 'before') {
                    found = i
                } else {
                    bidiOther = i
                }
            }
            if (cur.from == ch) {
                if (cur.from != cur.to && sticky != 'before') {
                    found = i
                } else {
                    bidiOther = i
                }
            }
        }
        return found != null ? found : bidiOther
    }

    // Bidirectional ordering algorithm
    // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
    // that this (partially) implements.

    // One-char codes used for character types:
    // L (L):   Left-to-Right
    // R (R):   Right-to-Left
    // r (AL):  Right-to-Left Arabic
    // 1 (EN):  European Number
    // + (ES):  European Number Separator
    // % (ET):  European Number Terminator
    // n (AN):  Arabic Number
    // , (CS):  Common Number Separator
    // m (NSM): Non-Spacing Mark
    // b (BN):  Boundary Neutral
    // s (B):   Paragraph Separator
    // t (S):   Segment Separator
    // w (WS):  Whitespace
    // N (ON):  Other Neutrals

    // Returns null if characters are ordered as they appear
    // (left-to-right), or an array of sections ({from, to, level}
    // objects) in the order in which they occur visually.
    var bidiOrdering = (function () {
        // Character types for codepoints 0 to 0xff
        var lowTypes =
            'bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLN'
        // Character types for codepoints 0x600 to 0x6f9
        var arabicTypes =
            'nnnnnnNNr%%r,rNNmmmmmmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmmmnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmnNmmmmmmrrmmNmmmmrr1111111111'
        function charType(code) {
            if (code <= 0xf7) {
                return lowTypes.charAt(code)
            } else if (0x590 <= code && code <= 0x5f4) {
                return 'R'
            } else if (0x600 <= code && code <= 0x6f9) {
                return arabicTypes.charAt(code - 0x600)
            } else if (0x6ee <= code && code <= 0x8ac) {
                return 'r'
            } else if (0x2000 <= code && code <= 0x200b) {
                return 'w'
            } else if (code == 0x200c) {
                return 'b'
            } else {
                return 'L'
            }
        }

        var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/
        var isNeutral = /[stwN]/,
            isStrong = /[LRr]/,
            countsAsLeft = /[Lb1n]/,
            countsAsNum = /[1n]/

        function BidiSpan(level, from, to) {
            this.level = level
            this.from = from
            this.to = to
        }

        return function (str, direction) {
            var outerType = direction == 'ltr' ? 'L' : 'R'

            if (str.length == 0 || (direction == 'ltr' && !bidiRE.test(str))) {
                return false
            }
            var len = str.length,
                types = []
            for (var i = 0; i < len; ++i) {
                types.push(charType(str.charCodeAt(i)))
            }

            // W1. Examine each non-spacing mark (NSM) in the level run, and
            // change the type of the NSM to the type of the previous
            // character. If the NSM is at the start of the level run, it will
            // get the type of sor.
            for (var i$1 = 0, prev = outerType; i$1 < len; ++i$1) {
                var type = types[i$1]
                if (type == 'm') {
                    types[i$1] = prev
                } else {
                    prev = type
                }
            }

            // W2. Search backwards from each instance of a European number
            // until the first strong type (R, L, AL, or sor) is found. If an
            // AL is found, change the type of the European number to Arabic
            // number.
            // W3. Change all ALs to R.
            for (var i$2 = 0, cur = outerType; i$2 < len; ++i$2) {
                var type$1 = types[i$2]
                if (type$1 == '1' && cur == 'r') {
                    types[i$2] = 'n'
                } else if (isStrong.test(type$1)) {
                    cur = type$1
                    if (type$1 == 'r') {
                        types[i$2] = 'R'
                    }
                }
            }

            // W4. A single European separator between two European numbers
            // changes to a European number. A single common separator between
            // two numbers of the same type changes to that type.
            for (var i$3 = 1, prev$1 = types[0]; i$3 < len - 1; ++i$3) {
                var type$2 = types[i$3]
                if (type$2 == '+' && prev$1 == '1' && types[i$3 + 1] == '1') {
                    types[i$3] = '1'
                } else if (type$2 == ',' && prev$1 == types[i$3 + 1] && (prev$1 == '1' || prev$1 == 'n')) {
                    types[i$3] = prev$1
                }
                prev$1 = type$2
            }

            // W5. A sequence of European terminators adjacent to European
            // numbers changes to all European numbers.
            // W6. Otherwise, separators and terminators change to Other
            // Neutral.
            for (var i$4 = 0; i$4 < len; ++i$4) {
                var type$3 = types[i$4]
                if (type$3 == ',') {
                    types[i$4] = 'N'
                } else if (type$3 == '%') {
                    var end = void 0
                    for (end = i$4 + 1; end < len && types[end] == '%'; ++end) {}
                    var replace = (i$4 && types[i$4 - 1] == '!') || (end < len && types[end] == '1') ? '1' : 'N'
                    for (var j = i$4; j < end; ++j) {
                        types[j] = replace
                    }
                    i$4 = end - 1
                }
            }

            // W7. Search backwards from each instance of a European number
            // until the first strong type (R, L, or sor) is found. If an L is
            // found, then change the type of the European number to L.
            for (var i$5 = 0, cur$1 = outerType; i$5 < len; ++i$5) {
                var type$4 = types[i$5]
                if (cur$1 == 'L' && type$4 == '1') {
                    types[i$5] = 'L'
                } else if (isStrong.test(type$4)) {
                    cur$1 = type$4
                }
            }

            // N1. A sequence of neutrals takes the direction of the
            // surrounding strong text if the text on both sides has the same
            // direction. European and Arabic numbers act as if they were R in
            // terms of their influence on neutrals. Start-of-level-run (sor)
            // and end-of-level-run (eor) are used at level run boundaries.
            // N2. Any remaining neutrals take the embedding direction.
            for (var i$6 = 0; i$6 < len; ++i$6) {
                if (isNeutral.test(types[i$6])) {
                    var end$1 = void 0
                    for (end$1 = i$6 + 1; end$1 < len && isNeutral.test(types[end$1]); ++end$1) {}
                    var before = (i$6 ? types[i$6 - 1] : outerType) == 'L'
                    var after = (end$1 < len ? types[end$1] : outerType) == 'L'
                    var replace$1 = before == after ? (before ? 'L' : 'R') : outerType
                    for (var j$1 = i$6; j$1 < end$1; ++j$1) {
                        types[j$1] = replace$1
                    }
                    i$6 = end$1 - 1
                }
            }

            // Here we depart from the documented algorithm, in order to avoid
            // building up an actual levels array. Since there are only three
            // levels (0, 1, 2) in an implementation that doesn't take
            // explicit embedding into account, we can build up the order on
            // the fly, without following the level-based algorithm.
            var order = [],
                m
            for (var i$7 = 0; i$7 < len; ) {
                if (countsAsLeft.test(types[i$7])) {
                    var start = i$7
                    for (++i$7; i$7 < len && countsAsLeft.test(types[i$7]); ++i$7) {}
                    order.push(new BidiSpan(0, start, i$7))
                } else {
                    var pos = i$7,
                        at = order.length,
                        isRTL = direction == 'rtl' ? 1 : 0
                    for (++i$7; i$7 < len && types[i$7] != 'L'; ++i$7) {}
                    for (var j$2 = pos; j$2 < i$7; ) {
                        if (countsAsNum.test(types[j$2])) {
                            if (pos < j$2) {
                                order.splice(at, 0, new BidiSpan(1, pos, j$2))
                                at += isRTL
                            }
                            var nstart = j$2
                            for (++j$2; j$2 < i$7 && countsAsNum.test(types[j$2]); ++j$2) {}
                            order.splice(at, 0, new BidiSpan(2, nstart, j$2))
                            at += isRTL
                            pos = j$2
                        } else {
                            ++j$2
                        }
                    }
                    if (pos < i$7) {
                        order.splice(at, 0, new BidiSpan(1, pos, i$7))
                    }
                }
            }
            if (direction == 'ltr') {
                if (order[0].level == 1 && (m = str.match(/^\s+/))) {
                    order[0].from = m[0].length
                    order.unshift(new BidiSpan(0, 0, m[0].length))
                }
                if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
                    lst(order).to -= m[0].length
                    order.push(new BidiSpan(0, len - m[0].length, len))
                }
            }

            return direction == 'rtl' ? order.reverse() : order
        }
    })()

    // Get the bidi ordering for the given line (and cache it). Returns
    // false for lines that are fully left-to-right, and an array of
    // BidiSpan objects otherwise.
    function getOrder(line, direction) {
        var order = line.order
        if (order == null) {
            order = line.order = bidiOrdering(line.text, direction)
        }
        return order
    }

    // EVENT HANDLING

    // Lightweight event framework. on/off also work on DOM nodes,
    // registering native DOM handlers.

    var noHandlers = []

    var on = function (emitter, type, f) {
        if (emitter.addEventListener) {
            emitter.addEventListener(type, f, false)
        } else if (emitter.attachEvent) {
            emitter.attachEvent('on' + type, f)
        } else {
            var map = emitter._handlers || (emitter._handlers = {})
            map[type] = (map[type] || noHandlers).concat(f)
        }
    }

    function getHandlers(emitter, type) {
        return (emitter._handlers && emitter._handlers[type]) || noHandlers
    }

    function off(emitter, type, f) {
        if (emitter.removeEventListener) {
            emitter.removeEventListener(type, f, false)
        } else if (emitter.detachEvent) {
            emitter.detachEvent('on' + type, f)
        } else {
            var map = emitter._handlers,
                arr = map && map[type]
            if (arr) {
                var index = indexOf(arr, f)
                if (index > -1) {
                    map[type] = arr.slice(0, index).concat(arr.slice(index + 1))
                }
            }
        }
    }

    function signal(emitter, type /*, values...*/) {
        var handlers = getHandlers(emitter, type)
        if (!handlers.length) {
            return
        }
        var args = Array.prototype.slice.call(arguments, 2)
        for (var i = 0; i < handlers.length; ++i) {
            handlers[i].apply(null, args)
        }
    }

    // The DOM events that CodeMirror handles can be overridden by
    // registering a (non-DOM) handler on the editor for the event name,
    // and preventDefault-ing the event in that handler.
    function signalDOMEvent(cm, e, override) {
        if (typeof e == 'string') {
            e = {
                type: e,
                preventDefault: function () {
                    this.defaultPrevented = true
                },
            }
        }
        signal(cm, override || e.type, cm, e)
        return e_defaultPrevented(e) || e.codemirrorIgnore
    }

    function signalCursorActivity(cm) {
        var arr = cm._handlers && cm._handlers.cursorActivity
        if (!arr) {
            return
        }
        var set = cm.curOp.cursorActivityHandlers || (cm.curOp.cursorActivityHandlers = [])
        for (var i = 0; i < arr.length; ++i) {
            if (indexOf(set, arr[i]) == -1) {
                set.push(arr[i])
            }
        }
    }

    function hasHandler(emitter, type) {
        return getHandlers(emitter, type).length > 0
    }

    // Add on and off methods to a constructor's prototype, to make
    // registering events on such objects more convenient.
    function eventMixin(ctor) {
        ctor.prototype.on = function (type, f) {
            on(this, type, f)
        }
        ctor.prototype.off = function (type, f) {
            off(this, type, f)
        }
    }

    // Due to the fact that we still support jurassic IE versions, some
    // compatibility wrappers are needed.

    function e_preventDefault(e) {
        if (e.preventDefault) {
            e.preventDefault()
        } else {
            e.returnValue = false
        }
    }
    function e_stopPropagation(e) {
        if (e.stopPropagation) {
            e.stopPropagation()
        } else {
            e.cancelBubble = true
        }
    }
    function e_defaultPrevented(e) {
        return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false
    }
    function e_stop(e) {
        e_preventDefault(e)
        e_stopPropagation(e)
    }

    function e_target(e) {
        return e.target || e.srcElement
    }
    function e_button(e) {
        var b = e.which
        if (b == null) {
            if (e.button & 1) {
                b = 1
            } else if (e.button & 2) {
                b = 3
            } else if (e.button & 4) {
                b = 2
            }
        }
        if (mac && e.ctrlKey && b == 1) {
            b = 3
        }
        return b
    }

    // Detect drag-and-drop
    var dragAndDrop = (function () {
        // There is *some* kind of drag-and-drop support in IE6-8, but I
        // couldn't get it to work yet.
        if (ie && ie_version < 9) {
            return false
        }
        var div = elt('div')
        return 'draggable' in div || 'dragDrop' in div
    })()

    var zwspSupported
    function zeroWidthElement(measure) {
        if (zwspSupported == null) {
            var test = elt('span', '\u200b')
            removeChildrenAndAdd(measure, elt('span', [test, document.createTextNode('x')]))
            if (measure.firstChild.offsetHeight != 0) {
                zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8)
            }
        }
        var node = zwspSupported ? elt('span', '\u200b') : elt('span', '\u00a0', null, 'display: inline-block; width: 1px; margin-right: -1px')
        node.setAttribute('cm-text', '')
        return node
    }

    // Feature-detect IE's crummy client rect reporting for bidi text
    var badBidiRects
    function hasBadBidiRects(measure) {
        if (badBidiRects != null) {
            return badBidiRects
        }
        var txt = removeChildrenAndAdd(measure, document.createTextNode('A\u062eA'))
        var r0 = range(txt, 0, 1).getBoundingClientRect()
        var r1 = range(txt, 1, 2).getBoundingClientRect()
        removeChildren(measure)
        if (!r0 || r0.left == r0.right) {
            return false
        } // Safari returns null in some cases (#2780)
        return (badBidiRects = r1.right - r0.right < 3)
    }

    // See if "".split is the broken IE version, if so, provide an
    // alternative way to split lines.
    var splitLinesAuto =
        '\n\nb'.split(/\n/).length != 3
            ? function (string) {
                  var pos = 0,
                      result = [],
                      l = string.length
                  while (pos <= l) {
                      var nl = string.indexOf('\n', pos)
                      if (nl == -1) {
                          nl = string.length
                      }
                      var line = string.slice(pos, string.charAt(nl - 1) == '\r' ? nl - 1 : nl)
                      var rt = line.indexOf('\r')
                      if (rt != -1) {
                          result.push(line.slice(0, rt))
                          pos += rt + 1
                      } else {
                          result.push(line)
                          pos = nl + 1
                      }
                  }
                  return result
              }
            : function (string) {
                  return string.split(/\r\n?|\n/)
              }

    var hasSelection = window.getSelection
        ? function (te) {
              try {
                  return te.selectionStart != te.selectionEnd
              } catch (e) {
                  return false
              }
          }
        : function (te) {
              var range
              try {
                  range = te.ownerDocument.selection.createRange()
              } catch (e) {}
              if (!range || range.parentElement() != te) {
                  return false
              }
              return range.compareEndPoints('StartToEnd', range) != 0
          }

    var hasCopyEvent = (function () {
        var e = elt('div')
        if ('oncopy' in e) {
            return true
        }
        e.setAttribute('oncopy', 'return;')
        return typeof e.oncopy == 'function'
    })()

    var badZoomedRects = null
    function hasBadZoomedRects(measure) {
        if (badZoomedRects != null) {
            return badZoomedRects
        }
        var node = removeChildrenAndAdd(measure, elt('span', 'x'))
        var normal = node.getBoundingClientRect()
        var fromRange = range(node, 0, 1).getBoundingClientRect()
        return (badZoomedRects = Math.abs(normal.left - fromRange.left) > 1)
    }

    // Known modes, by name and by MIME
    var modes = {},
        mimeModes = {}

    // Extra arguments are stored as the mode's dependencies, which is
    // used by (legacy) mechanisms like loadmode.js to automatically
    // load a mode. (Preferred mechanism is the require/define calls.)
    function defineMode(name, mode) {
        if (arguments.length > 2) {
            mode.dependencies = Array.prototype.slice.call(arguments, 2)
        }
        modes[name] = mode
    }

    function defineMIME(mime, spec) {
        mimeModes[mime] = spec
    }

    // Given a MIME type, a {name, ...options} config object, or a name
    // string, return a mode config object.
    function resolveMode(spec) {
        if (typeof spec == 'string' && mimeModes.hasOwnProperty(spec)) {
            spec = mimeModes[spec]
        } else if (spec && typeof spec.name == 'string' && mimeModes.hasOwnProperty(spec.name)) {
            var found = mimeModes[spec.name]
            if (typeof found == 'string') {
                found = { name: found }
            }
            spec = createObj(found, spec)
            spec.name = found.name
        } else if (typeof spec == 'string' && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
            return resolveMode('application/xml')
        } else if (typeof spec == 'string' && /^[\w\-]+\/[\w\-]+\+json$/.test(spec)) {
            return resolveMode('application/json')
        }
        if (typeof spec == 'string') {
            return { name: spec }
        } else {
            return spec || { name: 'null' }
        }
    }

    // Given a mode spec (anything that resolveMode accepts), find and
    // initialize an actual mode object.
    function getMode(options, spec) {
        spec = resolveMode(spec)
        var mfactory = modes[spec.name]
        if (!mfactory) {
            return getMode(options, 'text/plain')
        }
        var modeObj = mfactory(options, spec)
        if (modeExtensions.hasOwnProperty(spec.name)) {
            var exts = modeExtensions[spec.name]
            for (var prop in exts) {
                if (!exts.hasOwnProperty(prop)) {
                    continue
                }
                if (modeObj.hasOwnProperty(prop)) {
                    modeObj['_' + prop] = modeObj[prop]
                }
                modeObj[prop] = exts[prop]
            }
        }
        modeObj.name = spec.name
        if (spec.helperType) {
            modeObj.helperType = spec.helperType
        }
        if (spec.modeProps) {
            for (var prop$1 in spec.modeProps) {
                modeObj[prop$1] = spec.modeProps[prop$1]
            }
        }

        return modeObj
    }

    // This can be used to attach properties to mode objects from
    // outside the actual mode definition.
    var modeExtensions = {}
    function extendMode(mode, properties) {
        var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {})
        copyObj(properties, exts)
    }

    function copyState(mode, state) {
        if (state === true) {
            return state
        }
        if (mode.copyState) {
            return mode.copyState(state)
        }
        var nstate = {}
        for (var n in state) {
            var val = state[n]
            if (val instanceof Array) {
                val = val.concat([])
            }
            nstate[n] = val
        }
        return nstate
    }

    // Given a mode and a state (for that mode), find the inner mode and
    // state at the position that the state refers to.
    function innerMode(mode, state) {
        var info
        while (mode.innerMode) {
            info = mode.innerMode(state)
            if (!info || info.mode == mode) {
                break
            }
            state = info.state
            mode = info.mode
        }
        return info || { mode: mode, state: state }
    }

    function startState(mode, a1, a2) {
        return mode.startState ? mode.startState(a1, a2) : true
    }

    // STRING STREAM

    // Fed to the mode parsers, provides helper functions to make
    // parsers more succinct.

    var StringStream = function (string, tabSize, lineOracle) {
        this.pos = this.start = 0
        this.string = string
        this.tabSize = tabSize || 8
        this.lastColumnPos = this.lastColumnValue = 0
        this.lineStart = 0
        this.lineOracle = lineOracle
    }

    StringStream.prototype.eol = function () {
        return this.pos >= this.string.length
    }
    StringStream.prototype.sol = function () {
        return this.pos == this.lineStart
    }
    StringStream.prototype.peek = function () {
        return this.string.charAt(this.pos) || undefined
    }
    StringStream.prototype.next = function () {
        if (this.pos < this.string.length) {
            return this.string.charAt(this.pos++)
        }
    }
    StringStream.prototype.eat = function (match) {
        var ch = this.string.charAt(this.pos)
        var ok
        if (typeof match == 'string') {
            ok = ch == match
        } else {
            ok = ch && (match.test ? match.test(ch) : match(ch))
        }
        if (ok) {
            ++this.pos
            return ch
        }
    }
    StringStream.prototype.eatWhile = function (match) {
        var start = this.pos
        while (this.eat(match)) {}
        return this.pos > start
    }
    StringStream.prototype.eatSpace = function () {
        var start = this.pos
        while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) {
            ++this.pos
        }
        return this.pos > start
    }
    StringStream.prototype.skipToEnd = function () {
        this.pos = this.string.length
    }
    StringStream.prototype.skipTo = function (ch) {
        var found = this.string.indexOf(ch, this.pos)
        if (found > -1) {
            this.pos = found
            return true
        }
    }
    StringStream.prototype.backUp = function (n) {
        this.pos -= n
    }
    StringStream.prototype.column = function () {
        if (this.lastColumnPos < this.start) {
            this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue)
            this.lastColumnPos = this.start
        }
        return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0)
    }
    StringStream.prototype.indentation = function () {
        return countColumn(this.string, null, this.tabSize) - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0)
    }
    StringStream.prototype.match = function (pattern, consume, caseInsensitive) {
        if (typeof pattern == 'string') {
            var cased = function (str) {
                return caseInsensitive ? str.toLowerCase() : str
            }
            var substr = this.string.substr(this.pos, pattern.length)
            if (cased(substr) == cased(pattern)) {
                if (consume !== false) {
                    this.pos += pattern.length
                }
                return true
            }
        } else {
            var match = this.string.slice(this.pos).match(pattern)
            if (match && match.index > 0) {
                return null
            }
            if (match && consume !== false) {
                this.pos += match[0].length
            }
            return match
        }
    }
    StringStream.prototype.current = function () {
        return this.string.slice(this.start, this.pos)
    }
    StringStream.prototype.hideFirstChars = function (n, inner) {
        this.lineStart += n
        try {
            return inner()
        } finally {
            this.lineStart -= n
        }
    }
    StringStream.prototype.lookAhead = function (n) {
        var oracle = this.lineOracle
        return oracle && oracle.lookAhead(n)
    }
    StringStream.prototype.baseToken = function () {
        var oracle = this.lineOracle
        return oracle && oracle.baseToken(this.pos)
    }

    // Find the line object corresponding to the given line number.
    function getLine(doc, n) {
        n -= doc.first
        if (n < 0 || n >= doc.size) {
            throw new Error('There is no line ' + (n + doc.first) + ' in the document.')
        }
        var chunk = doc
        while (!chunk.lines) {
            for (var i = 0; ; ++i) {
                var child = chunk.children[i],
                    sz = child.chunkSize()
                if (n < sz) {
                    chunk = child
                    break
                }
                n -= sz
            }
        }
        return chunk.lines[n]
    }

    // Get the part of a document between two positions, as an array of
    // strings.
    function getBetween(doc, start, end) {
        var out = [],
            n = start.line
        doc.iter(start.line, end.line + 1, function (line) {
            var text = line.text
            if (n == end.line) {
                text = text.slice(0, end.ch)
            }
            if (n == start.line) {
                text = text.slice(start.ch)
            }
            out.push(text)
            ++n
        })
        return out
    }
    // Get the lines between from and to, as array of strings.
    function getLines(doc, from, to) {
        var out = []
        doc.iter(from, to, function (line) {
            out.push(line.text)
        }) // iter aborts when callback returns truthy value
        return out
    }

    // Update the height of a line, propagating the height change
    // upwards to parent nodes.
    function updateLineHeight(line, height) {
        var diff = height - line.height
        if (diff) {
            for (var n = line; n; n = n.parent) {
                n.height += diff
            }
        }
    }

    // Given a line object, find its line number by walking up through
    // its parent links.
    function lineNo(line) {
        if (line.parent == null) {
            return null
        }
        var cur = line.parent,
            no = indexOf(cur.lines, line)
        for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
            for (var i = 0; ; ++i) {
                if (chunk.children[i] == cur) {
                    break
                }
                no += chunk.children[i].chunkSize()
            }
        }
        return no + cur.first
    }

    // Find the line at the given vertical position, using the height
    // information in the document tree.
    function lineAtHeight(chunk, h) {
        var n = chunk.first
        outer: do {
            for (var i$1 = 0; i$1 < chunk.children.length; ++i$1) {
                var child = chunk.children[i$1],
                    ch = child.height
                if (h < ch) {
                    chunk = child
                    continue outer
                }
                h -= ch
                n += child.chunkSize()
            }
            return n
        } while (!chunk.lines)
        var i = 0
        for (; i < chunk.lines.length; ++i) {
            var line = chunk.lines[i],
                lh = line.height
            if (h < lh) {
                break
            }
            h -= lh
        }
        return n + i
    }

    function isLine(doc, l) {
        return l >= doc.first && l < doc.first + doc.size
    }

    function lineNumberFor(options, i) {
        return String(options.lineNumberFormatter(i + options.firstLineNumber))
    }

    // A Pos instance represents a position within the text.
    function Pos(line, ch, sticky) {
        if (sticky === void 0) sticky = null

        if (!(this instanceof Pos)) {
            return new Pos(line, ch, sticky)
        }
        this.line = line
        this.ch = ch
        this.sticky = sticky
    }

    // Compare two positions, return 0 if they are the same, a negative
    // number when a is less, and a positive number otherwise.
    function cmp(a, b) {
        return a.line - b.line || a.ch - b.ch
    }

    function equalCursorPos(a, b) {
        return a.sticky == b.sticky && cmp(a, b) == 0
    }

    function copyPos(x) {
        return Pos(x.line, x.ch)
    }
    function maxPos(a, b) {
        return cmp(a, b) < 0 ? b : a
    }
    function minPos(a, b) {
        return cmp(a, b) < 0 ? a : b
    }

    // Most of the external API clips given positions to make sure they
    // actually exist within the document.
    function clipLine(doc, n) {
        return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1))
    }
    function clipPos(doc, pos) {
        if (pos.line < doc.first) {
            return Pos(doc.first, 0)
        }
        var last = doc.first + doc.size - 1
        if (pos.line > last) {
            return Pos(last, getLine(doc, last).text.length)
        }
        return clipToLen(pos, getLine(doc, pos.line).text.length)
    }
    function clipToLen(pos, linelen) {
        var ch = pos.ch
        if (ch == null || ch > linelen) {
            return Pos(pos.line, linelen)
        } else if (ch < 0) {
            return Pos(pos.line, 0)
        } else {
            return pos
        }
    }
    function clipPosArray(doc, array) {
        var out = []
        for (var i = 0; i < array.length; i++) {
            out[i] = clipPos(doc, array[i])
        }
        return out
    }

    var SavedContext = function (state, lookAhead) {
        this.state = state
        this.lookAhead = lookAhead
    }

    var Context = function (doc, state, line, lookAhead) {
        this.state = state
        this.doc = doc
        this.line = line
        this.maxLookAhead = lookAhead || 0
        this.baseTokens = null
        this.baseTokenPos = 1
    }

    Context.prototype.lookAhead = function (n) {
        var line = this.doc.getLine(this.line + n)
        if (line != null && n > this.maxLookAhead) {
            this.maxLookAhead = n
        }
        return line
    }

    Context.prototype.baseToken = function (n) {
        if (!this.baseTokens) {
            return null
        }
        while (this.baseTokens[this.baseTokenPos] <= n) {
            this.baseTokenPos += 2
        }
        var type = this.baseTokens[this.baseTokenPos + 1]
        return { type: type && type.replace(/( |^)overlay .*/, ''), size: this.baseTokens[this.baseTokenPos] - n }
    }

    Context.prototype.nextLine = function () {
        this.line++
        if (this.maxLookAhead > 0) {
            this.maxLookAhead--
        }
    }

    Context.fromSaved = function (doc, saved, line) {
        if (saved instanceof SavedContext) {
            return new Context(doc, copyState(doc.mode, saved.state), line, saved.lookAhead)
        } else {
            return new Context(doc, copyState(doc.mode, saved), line)
        }
    }

    Context.prototype.save = function (copy) {
        var state = copy !== false ? copyState(this.doc.mode, this.state) : this.state
        return this.maxLookAhead > 0 ? new SavedContext(state, this.maxLookAhead) : state
    }

    // Compute a style array (an array starting with a mode generation
    // -- for invalidation -- followed by pairs of end positions and
    // style strings), which is used to highlight the tokens on the
    // line.
    function highlightLine(cm, line, context, forceToEnd) {
        // A styles array always starts with a number identifying the
        // mode/overlays that it is based on (for easy invalidation).
        var st = [cm.state.modeGen],
            lineClasses = {}
        // Compute the base array of styles
        runMode(
            cm,
            line.text,
            cm.doc.mode,
            context,
            function (end, style) {
                return st.push(end, style)
            },
            lineClasses,
            forceToEnd
        )
        var state = context.state

        // Run overlays, adjust style array.
        var loop = function (o) {
            context.baseTokens = st
            var overlay = cm.state.overlays[o],
                i = 1,
                at = 0
            context.state = true
            runMode(
                cm,
                line.text,
                overlay.mode,
                context,
                function (end, style) {
                    var start = i
                    // Ensure there's a token end at the current position, and that i points at it
                    while (at < end) {
                        var i_end = st[i]
                        if (i_end > end) {
                            st.splice(i, 1, end, st[i + 1], i_end)
                        }
                        i += 2
                        at = Math.min(end, i_end)
                    }
                    if (!style) {
                        return
                    }
                    if (overlay.opaque) {
                        st.splice(start, i - start, end, 'overlay ' + style)
                        i = start + 2
                    } else {
                        for (; start < i; start += 2) {
                            var cur = st[start + 1]
                            st[start + 1] = (cur ? cur + ' ' : '') + 'overlay ' + style
                        }
                    }
                },
                lineClasses
            )
            context.state = state
            context.baseTokens = null
            context.baseTokenPos = 1
        }

        for (var o = 0; o < cm.state.overlays.length; ++o) loop(o)

        return { styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null }
    }

    function getLineStyles(cm, line, updateFrontier) {
        if (!line.styles || line.styles[0] != cm.state.modeGen) {
            var context = getContextBefore(cm, lineNo(line))
            var resetState = line.text.length > cm.options.maxHighlightLength && copyState(cm.doc.mode, context.state)
            var result = highlightLine(cm, line, context)
            if (resetState) {
                context.state = resetState
            }
            line.stateAfter = context.save(!resetState)
            line.styles = result.styles
            if (result.classes) {
                line.styleClasses = result.classes
            } else if (line.styleClasses) {
                line.styleClasses = null
            }
            if (updateFrontier === cm.doc.highlightFrontier) {
                cm.doc.modeFrontier = Math.max(cm.doc.modeFrontier, ++cm.doc.highlightFrontier)
            }
        }
        return line.styles
    }

    function getContextBefore(cm, n, precise) {
        var doc = cm.doc,
            display = cm.display
        if (!doc.mode.startState) {
            return new Context(doc, true, n)
        }
        var start = findStartLine(cm, n, precise)
        var saved = start > doc.first && getLine(doc, start - 1).stateAfter
        var context = saved ? Context.fromSaved(doc, saved, start) : new Context(doc, startState(doc.mode), start)

        doc.iter(start, n, function (line) {
            processLine(cm, line.text, context)
            var pos = context.line
            line.stateAfter = pos == n - 1 || pos % 5 == 0 || (pos >= display.viewFrom && pos < display.viewTo) ? context.save() : null
            context.nextLine()
        })
        if (precise) {
            doc.modeFrontier = context.line
        }
        return context
    }

    // Lightweight form of highlight -- proceed over this line and
    // update state, but don't save a style array. Used for lines that
    // aren't currently visible.
    function processLine(cm, text, context, startAt) {
        var mode = cm.doc.mode
        var stream = new StringStream(text, cm.options.tabSize, context)
        stream.start = stream.pos = startAt || 0
        if (text == '') {
            callBlankLine(mode, context.state)
        }
        while (!stream.eol()) {
            readToken(mode, stream, context.state)
            stream.start = stream.pos
        }
    }

    function callBlankLine(mode, state) {
        if (mode.blankLine) {
            return mode.blankLine(state)
        }
        if (!mode.innerMode) {
            return
        }
        var inner = innerMode(mode, state)
        if (inner.mode.blankLine) {
            return inner.mode.blankLine(inner.state)
        }
    }

    function readToken(mode, stream, state, inner) {
        for (var i = 0; i < 10; i++) {
            if (inner) {
                inner[0] = innerMode(mode, state).mode
            }
            var style = mode.token(stream, state)
            if (stream.pos > stream.start) {
                return style
            }
        }
        throw new Error('Mode ' + mode.name + ' failed to advance stream.')
    }

    var Token = function (stream, type, state) {
        this.start = stream.start
        this.end = stream.pos
        this.string = stream.current()
        this.type = type || null
        this.state = state
    }

    // Utility for getTokenAt and getLineTokens
    function takeToken(cm, pos, precise, asArray) {
        var doc = cm.doc,
            mode = doc.mode,
            style
        pos = clipPos(doc, pos)
        var line = getLine(doc, pos.line),
            context = getContextBefore(cm, pos.line, precise)
        var stream = new StringStream(line.text, cm.options.tabSize, context),
            tokens
        if (asArray) {
            tokens = []
        }
        while ((asArray || stream.pos < pos.ch) && !stream.eol()) {
            stream.start = stream.pos
            style = readToken(mode, stream, context.state)
            if (asArray) {
                tokens.push(new Token(stream, style, copyState(doc.mode, context.state)))
            }
        }
        return asArray ? tokens : new Token(stream, style, context.state)
    }

    function extractLineClasses(type, output) {
        if (type) {
            for (;;) {
                var lineClass = type.match(/(?:^|\s+)line-(background-)?(\S+)/)
                if (!lineClass) {
                    break
                }
                type = type.slice(0, lineClass.index) + type.slice(lineClass.index + lineClass[0].length)
                var prop = lineClass[1] ? 'bgClass' : 'textClass'
                if (output[prop] == null) {
                    output[prop] = lineClass[2]
                } else if (!new RegExp('(?:^|\\s)' + lineClass[2] + '(?:$|\\s)').test(output[prop])) {
                    output[prop] += ' ' + lineClass[2]
                }
            }
        }
        return type
    }

    // Run the given mode's parser over a line, calling f for each token.
    function runMode(cm, text, mode, context, f, lineClasses, forceToEnd) {
        var flattenSpans = mode.flattenSpans
        if (flattenSpans == null) {
            flattenSpans = cm.options.flattenSpans
        }
        var curStart = 0,
            curStyle = null
        var stream = new StringStream(text, cm.options.tabSize, context),
            style
        var inner = cm.options.addModeClass && [null]
        if (text == '') {
            extractLineClasses(callBlankLine(mode, context.state), lineClasses)
        }
        while (!stream.eol()) {
            if (stream.pos > cm.options.maxHighlightLength) {
                flattenSpans = false
                if (forceToEnd) {
                    processLine(cm, text, context, stream.pos)
                }
                stream.pos = text.length
                style = null
            } else {
                style = extractLineClasses(readToken(mode, stream, context.state, inner), lineClasses)
            }
            if (inner) {
                var mName = inner[0].name
                if (mName) {
                    style = 'm-' + (style ? mName + ' ' + style : mName)
                }
            }
            if (!flattenSpans || curStyle != style) {
                while (curStart < stream.start) {
                    curStart = Math.min(stream.start, curStart + 5000)
                    f(curStart, curStyle)
                }
                curStyle = style
            }
            stream.start = stream.pos
        }
        while (curStart < stream.pos) {
            // Webkit seems to refuse to render text nodes longer than 57444
            // characters, and returns inaccurate measurements in nodes
            // starting around 5000 chars.
            var pos = Math.min(stream.pos, curStart + 5000)
            f(pos, curStyle)
            curStart = pos
        }
    }

    // Finds the line to start with when starting a parse. Tries to
    // find a line with a stateAfter, so that it can start with a
    // valid state. If that fails, it returns the line with the
    // smallest indentation, which tends to need the least context to
    // parse correctly.
    function findStartLine(cm, n, precise) {
        var minindent,
            minline,
            doc = cm.doc
        var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100)
        for (var search = n; search > lim; --search) {
            if (search <= doc.first) {
                return doc.first
            }
            var line = getLine(doc, search - 1),
                after = line.stateAfter
            if (after && (!precise || search + (after instanceof SavedContext ? after.lookAhead : 0) <= doc.modeFrontier)) {
                return search
            }
            var indented = countColumn(line.text, null, cm.options.tabSize)
            if (minline == null || minindent > indented) {
                minline = search - 1
                minindent = indented
            }
        }
        return minline
    }

    function retreatFrontier(doc, n) {
        doc.modeFrontier = Math.min(doc.modeFrontier, n)
        if (doc.highlightFrontier < n - 10) {
            return
        }
        var start = doc.first
        for (var line = n - 1; line > start; line--) {
            var saved = getLine(doc, line).stateAfter
            // change is on 3
            // state on line 1 looked ahead 2 -- so saw 3
            // test 1 + 2 < 3 should cover this
            if (saved && (!(saved instanceof SavedContext) || line + saved.lookAhead < n)) {
                start = line + 1
                break
            }
        }
        doc.highlightFrontier = Math.min(doc.highlightFrontier, start)
    }

    // Optimize some code when these features are not used.
    var sawReadOnlySpans = false,
        sawCollapsedSpans = false

    function seeReadOnlySpans() {
        sawReadOnlySpans = true
    }

    function seeCollapsedSpans() {
        sawCollapsedSpans = true
    }

    // TEXTMARKER SPANS

    function MarkedSpan(marker, from, to) {
        this.marker = marker
        this.from = from
        this.to = to
    }

    // Search an array of spans for a span matching the given marker.
    function getMarkedSpanFor(spans, marker) {
        if (spans) {
            for (var i = 0; i < spans.length; ++i) {
                var span = spans[i]
                if (span.marker == marker) {
                    return span
                }
            }
        }
    }

    // Remove a span from an array, returning undefined if no spans are
    // left (we don't store arrays for lines without spans).
    function removeMarkedSpan(spans, span) {
        var r
        for (var i = 0; i < spans.length; ++i) {
            if (spans[i] != span) {
                ;(r || (r = [])).push(spans[i])
            }
        }
        return r
    }

    // Add a span to a line.
    function addMarkedSpan(line, span, op) {
        var inThisOp = op && window.WeakSet && (op.markedSpans || (op.markedSpans = new WeakSet()))
        if (inThisOp && inThisOp.has(line.markedSpans)) {
            line.markedSpans.push(span)
        } else {
            line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span]
            if (inThisOp) {
                inThisOp.add(line.markedSpans)
            }
        }
        span.marker.attachLine(line)
    }

    // Used for the algorithm that adjusts markers for a change in the
    // document. These functions cut an array of spans at a given
    // character position, returning an array of remaining chunks (or
    // undefined if nothing remains).
    function markedSpansBefore(old, startCh, isInsert) {
        var nw
        if (old) {
            for (var i = 0; i < old.length; ++i) {
                var span = old[i],
                    marker = span.marker
                var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh)
                if (startsBefore || (span.from == startCh && marker.type == 'bookmark' && (!isInsert || !span.marker.insertLeft))) {
                    var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh)
                    ;(nw || (nw = [])).push(new MarkedSpan(marker, span.from, endsAfter ? null : span.to))
                }
            }
        }
        return nw
    }
    function markedSpansAfter(old, endCh, isInsert) {
        var nw
        if (old) {
            for (var i = 0; i < old.length; ++i) {
                var span = old[i],
                    marker = span.marker
                var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh)
                if (endsAfter || (span.from == endCh && marker.type == 'bookmark' && (!isInsert || span.marker.insertLeft))) {
                    var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh)
                    ;(nw || (nw = [])).push(new MarkedSpan(marker, startsBefore ? null : span.from - endCh, span.to == null ? null : span.to - endCh))
                }
            }
        }
        return nw
    }

    // Given a change object, compute the new set of marker spans that
    // cover the line in which the change took place. Removes spans
    // entirely within the change, reconnects spans belonging to the
    // same marker that appear on both sides of the change, and cuts off
    // spans partially within the change. Returns an array of span
    // arrays with one element for each line in (after) the change.
    function stretchSpansOverChange(doc, change) {
        if (change.full) {
            return null
        }
        var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans
        var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans
        if (!oldFirst && !oldLast) {
            return null
        }

        var startCh = change.from.ch,
            endCh = change.to.ch,
            isInsert = cmp(change.from, change.to) == 0
        // Get the spans that 'stick out' on both sides
        var first = markedSpansBefore(oldFirst, startCh, isInsert)
        var last = markedSpansAfter(oldLast, endCh, isInsert)

        // Next, merge those two ends
        var sameLine = change.text.length == 1,
            offset = lst(change.text).length + (sameLine ? startCh : 0)
        if (first) {
            // Fix up .to properties of first
            for (var i = 0; i < first.length; ++i) {
                var span = first[i]
                if (span.to == null) {
                    var found = getMarkedSpanFor(last, span.marker)
                    if (!found) {
                        span.to = startCh
                    } else if (sameLine) {
                        span.to = found.to == null ? null : found.to + offset
                    }
                }
            }
        }
        if (last) {
            // Fix up .from in last (or move them into first in case of sameLine)
            for (var i$1 = 0; i$1 < last.length; ++i$1) {
                var span$1 = last[i$1]
                if (span$1.to != null) {
                    span$1.to += offset
                }
                if (span$1.from == null) {
                    var found$1 = getMarkedSpanFor(first, span$1.marker)
                    if (!found$1) {
                        span$1.from = offset
                        if (sameLine) {
                            ;(first || (first = [])).push(span$1)
                        }
                    }
                } else {
                    span$1.from += offset
                    if (sameLine) {
                        ;(first || (first = [])).push(span$1)
                    }
                }
            }
        }
        // Make sure we didn't create any zero-length spans
        if (first) {
            first = clearEmptySpans(first)
        }
        if (last && last != first) {
            last = clearEmptySpans(last)
        }

        var newMarkers = [first]
        if (!sameLine) {
            // Fill gap with whole-line-spans
            var gap = change.text.length - 2,
                gapMarkers
            if (gap > 0 && first) {
                for (var i$2 = 0; i$2 < first.length; ++i$2) {
                    if (first[i$2].to == null) {
                        ;(gapMarkers || (gapMarkers = [])).push(new MarkedSpan(first[i$2].marker, null, null))
                    }
                }
            }
            for (var i$3 = 0; i$3 < gap; ++i$3) {
                newMarkers.push(gapMarkers)
            }
            newMarkers.push(last)
        }
        return newMarkers
    }

    // Remove spans that are empty and don't have a clearWhenEmpty
    // option of false.
    function clearEmptySpans(spans) {
        for (var i = 0; i < spans.length; ++i) {
            var span = spans[i]
            if (span.from != null && span.from == span.to && span.marker.clearWhenEmpty !== false) {
                spans.splice(i--, 1)
            }
        }
        if (!spans.length) {
            return null
        }
        return spans
    }

    // Used to 'clip' out readOnly ranges when making a change.
    function removeReadOnlyRanges(doc, from, to) {
        var markers = null
        doc.iter(from.line, to.line + 1, function (line) {
            if (line.markedSpans) {
                for (var i = 0; i < line.markedSpans.length; ++i) {
                    var mark = line.markedSpans[i].marker
                    if (mark.readOnly && (!markers || indexOf(markers, mark) == -1)) {
                        ;(markers || (markers = [])).push(mark)
                    }
                }
            }
        })
        if (!markers) {
            return null
        }
        var parts = [{ from: from, to: to }]
        for (var i = 0; i < markers.length; ++i) {
            var mk = markers[i],
                m = mk.find(0)
            for (var j = 0; j < parts.length; ++j) {
                var p = parts[j]
                if (cmp(p.to, m.from) < 0 || cmp(p.from, m.to) > 0) {
                    continue
                }
                var newParts = [j, 1],
                    dfrom = cmp(p.from, m.from),
                    dto = cmp(p.to, m.to)
                if (dfrom < 0 || (!mk.inclusiveLeft && !dfrom)) {
                    newParts.push({ from: p.from, to: m.from })
                }
                if (dto > 0 || (!mk.inclusiveRight && !dto)) {
                    newParts.push({ from: m.to, to: p.to })
                }
                parts.splice.apply(parts, newParts)
                j += newParts.length - 3
            }
        }
        return parts
    }

    // Connect or disconnect spans from a line.
    function detachMarkedSpans(line) {
        var spans = line.markedSpans
        if (!spans) {
            return
        }
        for (var i = 0; i < spans.length; ++i) {
            spans[i].marker.detachLine(line)
        }
        line.markedSpans = null
    }
    function attachMarkedSpans(line, spans) {
        if (!spans) {
            return
        }
        for (var i = 0; i < spans.length; ++i) {
            spans[i].marker.attachLine(line)
        }
        line.markedSpans = spans
    }

    // Helpers used when computing which overlapping collapsed span
    // counts as the larger one.
    function extraLeft(marker) {
        return marker.inclusiveLeft ? -1 : 0
    }
    function extraRight(marker) {
        return marker.inclusiveRight ? 1 : 0
    }

    // Returns a number indicating which of two overlapping collapsed
    // spans is larger (and thus includes the other). Falls back to
    // comparing ids when the spans cover exactly the same range.
    function compareCollapsedMarkers(a, b) {
        var lenDiff = a.lines.length - b.lines.length
        if (lenDiff != 0) {
            return lenDiff
        }
        var aPos = a.find(),
            bPos = b.find()
        var fromCmp = cmp(aPos.from, bPos.from) || extraLeft(a) - extraLeft(b)
        if (fromCmp) {
            return -fromCmp
        }
        var toCmp = cmp(aPos.to, bPos.to) || extraRight(a) - extraRight(b)
        if (toCmp) {
            return toCmp
        }
        return b.id - a.id
    }

    // Find out whether a line ends or starts in a collapsed span. If
    // so, return the marker for that span.
    function collapsedSpanAtSide(line, start) {
        var sps = sawCollapsedSpans && line.markedSpans,
            found
        if (sps) {
            for (var sp = void 0, i = 0; i < sps.length; ++i) {
                sp = sps[i]
                if (sp.marker.collapsed && (start ? sp.from : sp.to) == null && (!found || compareCollapsedMarkers(found, sp.marker) < 0)) {
                    found = sp.marker
                }
            }
        }
        return found
    }
    function collapsedSpanAtStart(line) {
        return collapsedSpanAtSide(line, true)
    }
    function collapsedSpanAtEnd(line) {
        return collapsedSpanAtSide(line, false)
    }

    function collapsedSpanAround(line, ch) {
        var sps = sawCollapsedSpans && line.markedSpans,
            found
        if (sps) {
            for (var i = 0; i < sps.length; ++i) {
                var sp = sps[i]
                if (sp.marker.collapsed && (sp.from == null || sp.from < ch) && (sp.to == null || sp.to > ch) && (!found || compareCollapsedMarkers(found, sp.marker) < 0)) {
                    found = sp.marker
                }
            }
        }
        return found
    }

    // Test whether there exists a collapsed span that partially
    // overlaps (covers the start or end, but not both) of a new span.
    // Such overlap is not allowed.
    function conflictingCollapsedRange(doc, lineNo, from, to, marker) {
        var line = getLine(doc, lineNo)
        var sps = sawCollapsedSpans && line.markedSpans
        if (sps) {
            for (var i = 0; i < sps.length; ++i) {
                var sp = sps[i]
                if (!sp.marker.collapsed) {
                    continue
                }
                var found = sp.marker.find(0)
                var fromCmp = cmp(found.from, from) || extraLeft(sp.marker) - extraLeft(marker)
                var toCmp = cmp(found.to, to) || extraRight(sp.marker) - extraRight(marker)
                if ((fromCmp >= 0 && toCmp <= 0) || (fromCmp <= 0 && toCmp >= 0)) {
                    continue
                }
                if (
                    (fromCmp <= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.to, from) >= 0 : cmp(found.to, from) > 0)) ||
                    (fromCmp >= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.from, to) <= 0 : cmp(found.from, to) < 0))
                ) {
                    return true
                }
            }
        }
    }

    // A visual line is a line as drawn on the screen. Folding, for
    // example, can cause multiple logical lines to appear on the same
    // visual line. This finds the start of the visual line that the
    // given line is part of (usually that is the line itself).
    function visualLine(line) {
        var merged
        while ((merged = collapsedSpanAtStart(line))) {
            line = merged.find(-1, true).line
        }
        return line
    }

    function visualLineEnd(line) {
        var merged
        while ((merged = collapsedSpanAtEnd(line))) {
            line = merged.find(1, true).line
        }
        return line
    }

    // Returns an array of logical lines that continue the visual line
    // started by the argument, or undefined if there are no such lines.
    function visualLineContinued(line) {
        var merged, lines
        while ((merged = collapsedSpanAtEnd(line))) {
            line = merged.find(1, true).line
            ;(lines || (lines = [])).push(line)
        }
        return lines
    }

    // Get the line number of the start of the visual line that the
    // given line number is part of.
    function visualLineNo(doc, lineN) {
        var line = getLine(doc, lineN),
            vis = visualLine(line)
        if (line == vis) {
            return lineN
        }
        return lineNo(vis)
    }

    // Get the line number of the start of the next visual line after
    // the given line.
    function visualLineEndNo(doc, lineN) {
        if (lineN > doc.lastLine()) {
            return lineN
        }
        var line = getLine(doc, lineN),
            merged
        if (!lineIsHidden(doc, line)) {
            return lineN
        }
        while ((merged = collapsedSpanAtEnd(line))) {
            line = merged.find(1, true).line
        }
        return lineNo(line) + 1
    }

    // Compute whether a line is hidden. Lines count as hidden when they
    // are part of a visual line that starts with another line, or when
    // they are entirely covered by collapsed, non-widget span.
    function lineIsHidden(doc, line) {
        var sps = sawCollapsedSpans && line.markedSpans
        if (sps) {
            for (var sp = void 0, i = 0; i < sps.length; ++i) {
                sp = sps[i]
                if (!sp.marker.collapsed) {
                    continue
                }
                if (sp.from == null) {
                    return true
                }
                if (sp.marker.widgetNode) {
                    continue
                }
                if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp)) {
                    return true
                }
            }
        }
    }
    function lineIsHiddenInner(doc, line, span) {
        if (span.to == null) {
            var end = span.marker.find(1, true)
            return lineIsHiddenInner(doc, end.line, getMarkedSpanFor(end.line.markedSpans, span.marker))
        }
        if (span.marker.inclusiveRight && span.to == line.text.length) {
            return true
        }
        for (var sp = void 0, i = 0; i < line.markedSpans.length; ++i) {
            sp = line.markedSpans[i]
            if (
                sp.marker.collapsed &&
                !sp.marker.widgetNode &&
                sp.from == span.to &&
                (sp.to == null || sp.to != span.from) &&
                (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
                lineIsHiddenInner(doc, line, sp)
            ) {
                return true
            }
        }
    }

    // Find the height above the given line.
    function heightAtLine(lineObj) {
        lineObj = visualLine(lineObj)

        var h = 0,
            chunk = lineObj.parent
        for (var i = 0; i < chunk.lines.length; ++i) {
            var line = chunk.lines[i]
            if (line == lineObj) {
                break
            } else {
                h += line.height
            }
        }
        for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
            for (var i$1 = 0; i$1 < p.children.length; ++i$1) {
                var cur = p.children[i$1]
                if (cur == chunk) {
                    break
                } else {
                    h += cur.height
                }
            }
        }
        return h
    }

    // Compute the character length of a line, taking into account
    // collapsed ranges (see markText) that might hide parts, and join
    // other lines onto it.
    function lineLength(line) {
        if (line.height == 0) {
            return 0
        }
        var len = line.text.length,
            merged,
            cur = line
        while ((merged = collapsedSpanAtStart(cur))) {
            var found = merged.find(0, true)
            cur = found.from.line
            len += found.from.ch - found.to.ch
        }
        cur = line
        while ((merged = collapsedSpanAtEnd(cur))) {
            var found$1 = merged.find(0, true)
            len -= cur.text.length - found$1.from.ch
            cur = found$1.to.line
            len += cur.text.length - found$1.to.ch
        }
        return len
    }

    // Find the longest line in the document.
    function findMaxLine(cm) {
        var d = cm.display,
            doc = cm.doc
        d.maxLine = getLine(doc, doc.first)
        d.maxLineLength = lineLength(d.maxLine)
        d.maxLineChanged = true
        doc.iter(function (line) {
            var len = lineLength(line)
            if (len > d.maxLineLength) {
                d.maxLineLength = len
                d.maxLine = line
            }
        })
    }

    // LINE DATA STRUCTURE

    // Line objects. These hold state related to a line, including
    // highlighting info (the styles array).
    var Line = function (text, markedSpans, estimateHeight) {
        this.text = text
        attachMarkedSpans(this, markedSpans)
        this.height = estimateHeight ? estimateHeight(this) : 1
    }

    Line.prototype.lineNo = function () {
        return lineNo(this)
    }
    eventMixin(Line)

    // Change the content (text, markers) of a line. Automatically
    // invalidates cached information and tries to re-estimate the
    // line's height.
    function updateLine(line, text, markedSpans, estimateHeight) {
        line.text = text
        if (line.stateAfter) {
            line.stateAfter = null
        }
        if (line.styles) {
            line.styles = null
        }
        if (line.order != null) {
            line.order = null
        }
        detachMarkedSpans(line)
        attachMarkedSpans(line, markedSpans)
        var estHeight = estimateHeight ? estimateHeight(line) : 1
        if (estHeight != line.height) {
            updateLineHeight(line, estHeight)
        }
    }

    // Detach a line from the document tree and its markers.
    function cleanUpLine(line) {
        line.parent = null
        detachMarkedSpans(line)
    }

    // Convert a style as returned by a mode (either null, or a string
    // containing one or more styles) to a CSS style. This is cached,
    // and also looks for line-wide styles.
    var styleToClassCache = {},
        styleToClassCacheWithMode = {}
    function interpretTokenStyle(style, options) {
        if (!style || /^\s*$/.test(style)) {
            return null
        }
        var cache = options.addModeClass ? styleToClassCacheWithMode : styleToClassCache
        return cache[style] || (cache[style] = style.replace(/\S+/g, 'cm-$&'))
    }

    // Render the DOM representation of the text of a line. Also builds
    // up a 'line map', which points at the DOM nodes that represent
    // specific stretches of text, and is used by the measuring code.
    // The returned object contains the DOM node, this map, and
    // information about line-wide styles that were set by the mode.
    function buildLineContent(cm, lineView) {
        // The padding-right forces the element to have a 'border', which
        // is needed on Webkit to be able to get line-level bounding
        // rectangles for it (in measureChar).
        var content = eltP('span', null, null, webkit ? 'padding-right: .1px' : null)
        var builder = { pre: eltP('pre', [content], 'CodeMirror-line'), content: content, col: 0, pos: 0, cm: cm, trailingSpace: false, splitSpaces: cm.getOption('lineWrapping') }
        lineView.measure = {}

        // Iterate over the logical lines that make up this visual line.
        for (var i = 0; i <= (lineView.rest ? lineView.rest.length : 0); i++) {
            var line = i ? lineView.rest[i - 1] : lineView.line,
                order = void 0
            builder.pos = 0
            builder.addToken = buildToken
            // Optionally wire in some hacks into the token-rendering
            // algorithm, to deal with browser quirks.
            if (hasBadBidiRects(cm.display.measure) && (order = getOrder(line, cm.doc.direction))) {
                builder.addToken = buildTokenBadBidi(builder.addToken, order)
            }
            builder.map = []
            var allowFrontierUpdate = lineView != cm.display.externalMeasured && lineNo(line)
            insertLineContent(line, builder, getLineStyles(cm, line, allowFrontierUpdate))
            if (line.styleClasses) {
                if (line.styleClasses.bgClass) {
                    builder.bgClass = joinClasses(line.styleClasses.bgClass, builder.bgClass || '')
                }
                if (line.styleClasses.textClass) {
                    builder.textClass = joinClasses(line.styleClasses.textClass, builder.textClass || '')
                }
            }

            // Ensure at least a single node is present, for measuring.
            if (builder.map.length == 0) {
                builder.map.push(0, 0, builder.content.appendChild(zeroWidthElement(cm.display.measure)))
            }

            // Store the map and a cache object for the current logical line
            if (i == 0) {
                lineView.measure.map = builder.map
                lineView.measure.cache = {}
            } else {
                ;(lineView.measure.maps || (lineView.measure.maps = [])).push(builder.map)
                ;(lineView.measure.caches || (lineView.measure.caches = [])).push({})
            }
        }

        // See issue #2901
        if (webkit) {
            var last = builder.content.lastChild
            if (/\bcm-tab\b/.test(last.className) || (last.querySelector && last.querySelector('.cm-tab'))) {
                builder.content.className = 'cm-tab-wrap-hack'
            }
        }

        signal(cm, 'renderLine', cm, lineView.line, builder.pre)
        if (builder.pre.className) {
            builder.textClass = joinClasses(builder.pre.className, builder.textClass || '')
        }

        return builder
    }

    function defaultSpecialCharPlaceholder(ch) {
        var token = elt('span', '\u2022', 'cm-invalidchar')
        token.title = '\\u' + ch.charCodeAt(0).toString(16)
        token.setAttribute('aria-label', token.title)
        return token
    }

    // Build up the DOM representation for a single token, and add it to
    // the line map. Takes care to render special characters separately.
    function buildToken(builder, text, style, startStyle, endStyle, css, attributes) {
        if (!text) {
            return
        }
        var displayText = builder.splitSpaces ? splitSpaces(text, builder.trailingSpace) : text
        var special = builder.cm.state.specialChars,
            mustWrap = false
        var content
        if (!special.test(text)) {
            builder.col += text.length
            content = document.createTextNode(displayText)
            builder.map.push(builder.pos, builder.pos + text.length, content)
            if (ie && ie_version < 9) {
                mustWrap = true
            }
            builder.pos += text.length
        } else {
            content = document.createDocumentFragment()
            var pos = 0
            while (true) {
                special.lastIndex = pos
                var m = special.exec(text)
                var skipped = m ? m.index - pos : text.length - pos
                if (skipped) {
                    var txt = document.createTextNode(displayText.slice(pos, pos + skipped))
                    if (ie && ie_version < 9) {
                        content.appendChild(elt('span', [txt]))
                    } else {
                        content.appendChild(txt)
                    }
                    builder.map.push(builder.pos, builder.pos + skipped, txt)
                    builder.col += skipped
                    builder.pos += skipped
                }
                if (!m) {
                    break
                }
                pos += skipped + 1
                var txt$1 = void 0
                if (m[0] == '\t') {
                    var tabSize = builder.cm.options.tabSize,
                        tabWidth = tabSize - (builder.col % tabSize)
                    txt$1 = content.appendChild(elt('span', spaceStr(tabWidth), 'cm-tab'))
                    txt$1.setAttribute('role', 'presentation')
                    txt$1.setAttribute('cm-text', '\t')
                    builder.col += tabWidth
                } else if (m[0] == '\r' || m[0] == '\n') {
                    txt$1 = content.appendChild(elt('span', m[0] == '\r' ? '\u240d' : '\u2424', 'cm-invalidchar'))
                    txt$1.setAttribute('cm-text', m[0])
                    builder.col += 1
                } else {
                    txt$1 = builder.cm.options.specialCharPlaceholder(m[0])
                    txt$1.setAttribute('cm-text', m[0])
                    if (ie && ie_version < 9) {
                        content.appendChild(elt('span', [txt$1]))
                    } else {
                        content.appendChild(txt$1)
                    }
                    builder.col += 1
                }
                builder.map.push(builder.pos, builder.pos + 1, txt$1)
                builder.pos++
            }
        }
        builder.trailingSpace = displayText.charCodeAt(text.length - 1) == 32
        if (style || startStyle || endStyle || mustWrap || css || attributes) {
            var fullStyle = style || ''
            if (startStyle) {
                fullStyle += startStyle
            }
            if (endStyle) {
                fullStyle += endStyle
            }
            var token = elt('span', [content], fullStyle, css)
            if (attributes) {
                for (var attr in attributes) {
                    if (attributes.hasOwnProperty(attr) && attr != 'style' && attr != 'class') {
                        token.setAttribute(attr, attributes[attr])
                    }
                }
            }
            return builder.content.appendChild(token)
        }
        builder.content.appendChild(content)
    }

    // Change some spaces to NBSP to prevent the browser from collapsing
    // trailing spaces at the end of a line when rendering text (issue #1362).
    function splitSpaces(text, trailingBefore) {
        if (text.length > 1 && !/  /.test(text)) {
            return text
        }
        var spaceBefore = trailingBefore,
            result = ''
        for (var i = 0; i < text.length; i++) {
            var ch = text.charAt(i)
            if (ch == ' ' && spaceBefore && (i == text.length - 1 || text.charCodeAt(i + 1) == 32)) {
                ch = '\u00a0'
            }
            result += ch
            spaceBefore = ch == ' '
        }
        return result
    }

    // Work around nonsense dimensions being reported for stretches of
    // right-to-left text.
    function buildTokenBadBidi(inner, order) {
        return function (builder, text, style, startStyle, endStyle, css, attributes) {
            style = style ? style + ' cm-force-border' : 'cm-force-border'
            var start = builder.pos,
                end = start + text.length
            for (;;) {
                // Find the part that overlaps with the start of this text
                var part = void 0
                for (var i = 0; i < order.length; i++) {
                    part = order[i]
                    if (part.to > start && part.from <= start) {
                        break
                    }
                }
                if (part.to >= end) {
                    return inner(builder, text, style, startStyle, endStyle, css, attributes)
                }
                inner(builder, text.slice(0, part.to - start), style, startStyle, null, css, attributes)
                startStyle = null
                text = text.slice(part.to - start)
                start = part.to
            }
        }
    }

    function buildCollapsedSpan(builder, size, marker, ignoreWidget) {
        var widget = !ignoreWidget && marker.widgetNode
        if (widget) {
            builder.map.push(builder.pos, builder.pos + size, widget)
        }
        if (!ignoreWidget && builder.cm.display.input.needsContentAttribute) {
            if (!widget) {
                widget = builder.content.appendChild(document.createElement('span'))
            }
            widget.setAttribute('cm-marker', marker.id)
        }
        if (widget) {
            builder.cm.display.input.setUneditable(widget)
            builder.content.appendChild(widget)
        }
        builder.pos += size
        builder.trailingSpace = false
    }

    // Outputs a number of spans to make up a line, taking highlighting
    // and marked text into account.
    function insertLineContent(line, builder, styles) {
        var spans = line.markedSpans,
            allText = line.text,
            at = 0
        if (!spans) {
            for (var i$1 = 1; i$1 < styles.length; i$1 += 2) {
                builder.addToken(builder, allText.slice(at, (at = styles[i$1])), interpretTokenStyle(styles[i$1 + 1], builder.cm.options))
            }
            return
        }

        var len = allText.length,
            pos = 0,
            i = 1,
            text = '',
            style,
            css
        var nextChange = 0,
            spanStyle,
            spanEndStyle,
            spanStartStyle,
            collapsed,
            attributes
        for (;;) {
            if (nextChange == pos) {
                // Update current marker set
                spanStyle = spanEndStyle = spanStartStyle = css = ''
                attributes = null
                collapsed = null
                nextChange = Infinity
                var foundBookmarks = [],
                    endStyles = void 0
                for (var j = 0; j < spans.length; ++j) {
                    var sp = spans[j],
                        m = sp.marker
                    if (m.type == 'bookmark' && sp.from == pos && m.widgetNode) {
                        foundBookmarks.push(m)
                    } else if (sp.from <= pos && (sp.to == null || sp.to > pos || (m.collapsed && sp.to == pos && sp.from == pos))) {
                        if (sp.to != null && sp.to != pos && nextChange > sp.to) {
                            nextChange = sp.to
                            spanEndStyle = ''
                        }
                        if (m.className) {
                            spanStyle += ' ' + m.className
                        }
                        if (m.css) {
                            css = (css ? css + ';' : '') + m.css
                        }
                        if (m.startStyle && sp.from == pos) {
                            spanStartStyle += ' ' + m.startStyle
                        }
                        if (m.endStyle && sp.to == nextChange) {
                            ;(endStyles || (endStyles = [])).push(m.endStyle, sp.to)
                        }
                        // support for the old title property
                        // https://github.com/codemirror/CodeMirror/pull/5673
                        if (m.title) {
                            ;(attributes || (attributes = {})).title = m.title
                        }
                        if (m.attributes) {
                            for (var attr in m.attributes) {
                                ;(attributes || (attributes = {}))[attr] = m.attributes[attr]
                            }
                        }
                        if (m.collapsed && (!collapsed || compareCollapsedMarkers(collapsed.marker, m) < 0)) {
                            collapsed = sp
                        }
                    } else if (sp.from > pos && nextChange > sp.from) {
                        nextChange = sp.from
                    }
                }
                if (endStyles) {
                    for (var j$1 = 0; j$1 < endStyles.length; j$1 += 2) {
                        if (endStyles[j$1 + 1] == nextChange) {
                            spanEndStyle += ' ' + endStyles[j$1]
                        }
                    }
                }

                if (!collapsed || collapsed.from == pos) {
                    for (var j$2 = 0; j$2 < foundBookmarks.length; ++j$2) {
                        buildCollapsedSpan(builder, 0, foundBookmarks[j$2])
                    }
                }
                if (collapsed && (collapsed.from || 0) == pos) {
                    buildCollapsedSpan(builder, (collapsed.to == null ? len + 1 : collapsed.to) - pos, collapsed.marker, collapsed.from == null)
                    if (collapsed.to == null) {
                        return
                    }
                    if (collapsed.to == pos) {
                        collapsed = false
                    }
                }
            }
            if (pos >= len) {
                break
            }

            var upto = Math.min(len, nextChange)
            while (true) {
                if (text) {
                    var end = pos + text.length
                    if (!collapsed) {
                        var tokenText = end > upto ? text.slice(0, upto - pos) : text
                        builder.addToken(builder, tokenText, style ? style + spanStyle : spanStyle, spanStartStyle, pos + tokenText.length == nextChange ? spanEndStyle : '', css, attributes)
                    }
                    if (end >= upto) {
                        text = text.slice(upto - pos)
                        pos = upto
                        break
                    }
                    pos = end
                    spanStartStyle = ''
                }
                text = allText.slice(at, (at = styles[i++]))
                style = interpretTokenStyle(styles[i++], builder.cm.options)
            }
        }
    }

    // These objects are used to represent the visible (currently drawn)
    // part of the document. A LineView may correspond to multiple
    // logical lines, if those are connected by collapsed ranges.
    function LineView(doc, line, lineN) {
        // The starting line
        this.line = line
        // Continuing lines, if any
        this.rest = visualLineContinued(line)
        // Number of logical lines in this visual line
        this.size = this.rest ? lineNo(lst(this.rest)) - lineN + 1 : 1
        this.node = this.text = null
        this.hidden = lineIsHidden(doc, line)
    }

    // Create a range of LineView objects for the given lines.
    function buildViewArray(cm, from, to) {
        var array = [],
            nextPos
        for (var pos = from; pos < to; pos = nextPos) {
            var view = new LineView(cm.doc, getLine(cm.doc, pos), pos)
            nextPos = pos + view.size
            array.push(view)
        }
        return array
    }

    var operationGroup = null

    function pushOperation(op) {
        if (operationGroup) {
            operationGroup.ops.push(op)
        } else {
            op.ownsGroup = operationGroup = {
                ops: [op],
                delayedCallbacks: [],
            }
        }
    }

    function fireCallbacksForOps(group) {
        // Calls delayed callbacks and cursorActivity handlers until no
        // new ones appear
        var callbacks = group.delayedCallbacks,
            i = 0
        do {
            for (; i < callbacks.length; i++) {
                callbacks[i].call(null)
            }
            for (var j = 0; j < group.ops.length; j++) {
                var op = group.ops[j]
                if (op.cursorActivityHandlers) {
                    while (op.cursorActivityCalled < op.cursorActivityHandlers.length) {
                        op.cursorActivityHandlers[op.cursorActivityCalled++].call(null, op.cm)
                    }
                }
            }
        } while (i < callbacks.length)
    }

    function finishOperation(op, endCb) {
        var group = op.ownsGroup
        if (!group) {
            return
        }

        try {
            fireCallbacksForOps(group)
        } finally {
            operationGroup = null
            endCb(group)
        }
    }

    var orphanDelayedCallbacks = null

    // Often, we want to signal events at a point where we are in the
    // middle of some work, but don't want the handler to start calling
    // other methods on the editor, which might be in an inconsistent
    // state or simply not expect any other events to happen.
    // signalLater looks whether there are any handlers, and schedules
    // them to be executed when the last operation ends, or, if no
    // operation is active, when a timeout fires.
    function signalLater(emitter, type /*, values...*/) {
        var arr = getHandlers(emitter, type)
        if (!arr.length) {
            return
        }
        var args = Array.prototype.slice.call(arguments, 2),
            list
        if (operationGroup) {
            list = operationGroup.delayedCallbacks
        } else if (orphanDelayedCallbacks) {
            list = orphanDelayedCallbacks
        } else {
            list = orphanDelayedCallbacks = []
            setTimeout(fireOrphanDelayed, 0)
        }
        var loop = function (i) {
            list.push(function () {
                return arr[i].apply(null, args)
            })
        }

        for (var i = 0; i < arr.length; ++i) loop(i)
    }

    function fireOrphanDelayed() {
        var delayed = orphanDelayedCallbacks
        orphanDelayedCallbacks = null
        for (var i = 0; i < delayed.length; ++i) {
            delayed[i]()
        }
    }

    // When an aspect of a line changes, a string is added to
    // lineView.changes. This updates the relevant part of the line's
    // DOM structure.
    function updateLineForChanges(cm, lineView, lineN, dims) {
        for (var j = 0; j < lineView.changes.length; j++) {
            var type = lineView.changes[j]
            if (type == 'text') {
                updateLineText(cm, lineView)
            } else if (type == 'gutter') {
                updateLineGutter(cm, lineView, lineN, dims)
            } else if (type == 'class') {
                updateLineClasses(cm, lineView)
            } else if (type == 'widget') {
                updateLineWidgets(cm, lineView, dims)
            }
        }
        lineView.changes = null
    }

    // Lines with gutter elements, widgets or a background class need to
    // be wrapped, and have the extra elements added to the wrapper div
    function ensureLineWrapped(lineView) {
        if (lineView.node == lineView.text) {
            lineView.node = elt('div', null, null, 'position: relative')
            if (lineView.text.parentNode) {
                lineView.text.parentNode.replaceChild(lineView.node, lineView.text)
            }
            lineView.node.appendChild(lineView.text)
            if (ie && ie_version < 8) {
                lineView.node.style.zIndex = 2
            }
        }
        return lineView.node
    }

    function updateLineBackground(cm, lineView) {
        var cls = lineView.bgClass ? lineView.bgClass + ' ' + (lineView.line.bgClass || '') : lineView.line.bgClass
        if (cls) {
            cls += ' CodeMirror-linebackground'
        }
        if (lineView.background) {
            if (cls) {
                lineView.background.className = cls
            } else {
                lineView.background.parentNode.removeChild(lineView.background)
                lineView.background = null
            }
        } else if (cls) {
            var wrap = ensureLineWrapped(lineView)
            lineView.background = wrap.insertBefore(elt('div', null, cls), wrap.firstChild)
            cm.display.input.setUneditable(lineView.background)
        }
    }

    // Wrapper around buildLineContent which will reuse the structure
    // in display.externalMeasured when possible.
    function getLineContent(cm, lineView) {
        var ext = cm.display.externalMeasured
        if (ext && ext.line == lineView.line) {
            cm.display.externalMeasured = null
            lineView.measure = ext.measure
            return ext.built
        }
        return buildLineContent(cm, lineView)
    }

    // Redraw the line's text. Interacts with the background and text
    // classes because the mode may output tokens that influence these
    // classes.
    function updateLineText(cm, lineView) {
        var cls = lineView.text.className
        var built = getLineContent(cm, lineView)
        if (lineView.text == lineView.node) {
            lineView.node = built.pre
        }
        lineView.text.parentNode.replaceChild(built.pre, lineView.text)
        lineView.text = built.pre
        if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {
            lineView.bgClass = built.bgClass
            lineView.textClass = built.textClass
            updateLineClasses(cm, lineView)
        } else if (cls) {
            lineView.text.className = cls
        }
    }

    function updateLineClasses(cm, lineView) {
        updateLineBackground(cm, lineView)
        if (lineView.line.wrapClass) {
            ensureLineWrapped(lineView).className = lineView.line.wrapClass
        } else if (lineView.node != lineView.text) {
            lineView.node.className = ''
        }
        var textClass = lineView.textClass ? lineView.textClass + ' ' + (lineView.line.textClass || '') : lineView.line.textClass
        lineView.text.className = textClass || ''
    }

    function updateLineGutter(cm, lineView, lineN, dims) {
        if (lineView.gutter) {
            lineView.node.removeChild(lineView.gutter)
            lineView.gutter = null
        }
        if (lineView.gutterBackground) {
            lineView.node.removeChild(lineView.gutterBackground)
            lineView.gutterBackground = null
        }
        if (lineView.line.gutterClass) {
            var wrap = ensureLineWrapped(lineView)
            lineView.gutterBackground = elt(
                'div',
                null,
                'CodeMirror-gutter-background ' + lineView.line.gutterClass,
                'left: ' + (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + 'px; width: ' + dims.gutterTotalWidth + 'px'
            )
            cm.display.input.setUneditable(lineView.gutterBackground)
            wrap.insertBefore(lineView.gutterBackground, lineView.text)
        }
        var markers = lineView.line.gutterMarkers
        if (cm.options.lineNumbers || markers) {
            var wrap$1 = ensureLineWrapped(lineView)
            var gutterWrap = (lineView.gutter = elt('div', null, 'CodeMirror-gutter-wrapper', 'left: ' + (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + 'px'))
            gutterWrap.setAttribute('aria-hidden', 'true')
            cm.display.input.setUneditable(gutterWrap)
            wrap$1.insertBefore(gutterWrap, lineView.text)
            if (lineView.line.gutterClass) {
                gutterWrap.className += ' ' + lineView.line.gutterClass
            }
            if (cm.options.lineNumbers && (!markers || !markers['CodeMirror-linenumbers'])) {
                lineView.lineNumber = gutterWrap.appendChild(
                    elt(
                        'div',
                        lineNumberFor(cm.options, lineN),
                        'CodeMirror-linenumber CodeMirror-gutter-elt',
                        'left: ' + dims.gutterLeft['CodeMirror-linenumbers'] + 'px; width: ' + cm.display.lineNumInnerWidth + 'px'
                    )
                )
            }
            if (markers) {
                for (var k = 0; k < cm.display.gutterSpecs.length; ++k) {
                    var id = cm.display.gutterSpecs[k].className,
                        found = markers.hasOwnProperty(id) && markers[id]
                    if (found) {
                        gutterWrap.appendChild(elt('div', [found], 'CodeMirror-gutter-elt', 'left: ' + dims.gutterLeft[id] + 'px; width: ' + dims.gutterWidth[id] + 'px'))
                    }
                }
            }
        }
    }

    function updateLineWidgets(cm, lineView, dims) {
        if (lineView.alignable) {
            lineView.alignable = null
        }
        var isWidget = classTest('CodeMirror-linewidget')
        for (var node = lineView.node.firstChild, next = void 0; node; node = next) {
            next = node.nextSibling
            if (isWidget.test(node.className)) {
                lineView.node.removeChild(node)
            }
        }
        insertLineWidgets(cm, lineView, dims)
    }

    // Build a line's DOM representation from scratch
    function buildLineElement(cm, lineView, lineN, dims) {
        var built = getLineContent(cm, lineView)
        lineView.text = lineView.node = built.pre
        if (built.bgClass) {
            lineView.bgClass = built.bgClass
        }
        if (built.textClass) {
            lineView.textClass = built.textClass
        }

        updateLineClasses(cm, lineView)
        updateLineGutter(cm, lineView, lineN, dims)
        insertLineWidgets(cm, lineView, dims)
        return lineView.node
    }

    // A lineView may contain multiple logical lines (when merged by
    // collapsed spans). The widgets for all of them need to be drawn.
    function insertLineWidgets(cm, lineView, dims) {
        insertLineWidgetsFor(cm, lineView.line, lineView, dims, true)
        if (lineView.rest) {
            for (var i = 0; i < lineView.rest.length; i++) {
                insertLineWidgetsFor(cm, lineView.rest[i], lineView, dims, false)
            }
        }
    }

    function insertLineWidgetsFor(cm, line, lineView, dims, allowAbove) {
        if (!line.widgets) {
            return
        }
        var wrap = ensureLineWrapped(lineView)
        for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
            var widget = ws[i],
                node = elt('div', [widget.node], 'CodeMirror-linewidget' + (widget.className ? ' ' + widget.className : ''))
            if (!widget.handleMouseEvents) {
                node.setAttribute('cm-ignore-events', 'true')
            }
            positionLineWidget(widget, node, lineView, dims)
            cm.display.input.setUneditable(node)
            if (allowAbove && widget.above) {
                wrap.insertBefore(node, lineView.gutter || lineView.text)
            } else {
                wrap.appendChild(node)
            }
            signalLater(widget, 'redraw')
        }
    }

    function positionLineWidget(widget, node, lineView, dims) {
        if (widget.noHScroll) {
            ;(lineView.alignable || (lineView.alignable = [])).push(node)
            var width = dims.wrapperWidth
            node.style.left = dims.fixedPos + 'px'
            if (!widget.coverGutter) {
                width -= dims.gutterTotalWidth
                node.style.paddingLeft = dims.gutterTotalWidth + 'px'
            }
            node.style.width = width + 'px'
        }
        if (widget.coverGutter) {
            node.style.zIndex = 5
            node.style.position = 'relative'
            if (!widget.noHScroll) {
                node.style.marginLeft = -dims.gutterTotalWidth + 'px'
            }
        }
    }

    function widgetHeight(widget) {
        if (widget.height != null) {
            return widget.height
        }
        var cm = widget.doc.cm
        if (!cm) {
            return 0
        }
        if (!contains(document.body, widget.node)) {
            var parentStyle = 'position: relative;'
            if (widget.coverGutter) {
                parentStyle += 'margin-left: -' + cm.display.gutters.offsetWidth + 'px;'
            }
            if (widget.noHScroll) {
                parentStyle += 'width: ' + cm.display.wrapper.clientWidth + 'px;'
            }
            removeChildrenAndAdd(cm.display.measure, elt('div', [widget.node], null, parentStyle))
        }
        return (widget.height = widget.node.parentNode.offsetHeight)
    }

    // Return true when the given mouse event happened in a widget
    function eventInWidget(display, e) {
        for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
            if (!n || (n.nodeType == 1 && n.getAttribute('cm-ignore-events') == 'true') || (n.parentNode == display.sizer && n != display.mover)) {
                return true
            }
        }
    }

    // POSITION MEASUREMENT

    function paddingTop(display) {
        return display.lineSpace.offsetTop
    }
    function paddingVert(display) {
        return display.mover.offsetHeight - display.lineSpace.offsetHeight
    }
    function paddingH(display) {
        if (display.cachedPaddingH) {
            return display.cachedPaddingH
        }
        var e = removeChildrenAndAdd(display.measure, elt('pre', 'x', 'CodeMirror-line-like'))
        var style = window.getComputedStyle ? window.getComputedStyle(e) : e.currentStyle
        var data = { left: parseInt(style.paddingLeft), right: parseInt(style.paddingRight) }
        if (!isNaN(data.left) && !isNaN(data.right)) {
            display.cachedPaddingH = data
        }
        return data
    }

    function scrollGap(cm) {
        return scrollerGap - cm.display.nativeBarWidth
    }
    function displayWidth(cm) {
        return cm.display.scroller.clientWidth - scrollGap(cm) - cm.display.barWidth
    }
    function displayHeight(cm) {
        return cm.display.scroller.clientHeight - scrollGap(cm) - cm.display.barHeight
    }

    // Ensure the lineView.wrapping.heights array is populated. This is
    // an array of bottom offsets for the lines that make up a drawn
    // line. When lineWrapping is on, there might be more than one
    // height.
    function ensureLineHeights(cm, lineView, rect) {
        var wrapping = cm.options.lineWrapping
        var curWidth = wrapping && displayWidth(cm)
        if (!lineView.measure.heights || (wrapping && lineView.measure.width != curWidth)) {
            var heights = (lineView.measure.heights = [])
            if (wrapping) {
                lineView.measure.width = curWidth
                var rects = lineView.text.firstChild.getClientRects()
                for (var i = 0; i < rects.length - 1; i++) {
                    var cur = rects[i],
                        next = rects[i + 1]
                    if (Math.abs(cur.bottom - next.bottom) > 2) {
                        heights.push((cur.bottom + next.top) / 2 - rect.top)
                    }
                }
            }
            heights.push(rect.bottom - rect.top)
        }
    }

    // Find a line map (mapping character offsets to text nodes) and a
    // measurement cache for the given line number. (A line view might
    // contain multiple lines when collapsed ranges are present.)
    function mapFromLineView(lineView, line, lineN) {
        if (lineView.line == line) {
            return { map: lineView.measure.map, cache: lineView.measure.cache }
        }
        if (lineView.rest) {
            for (var i = 0; i < lineView.rest.length; i++) {
                if (lineView.rest[i] == line) {
                    return { map: lineView.measure.maps[i], cache: lineView.measure.caches[i] }
                }
            }
            for (var i$1 = 0; i$1 < lineView.rest.length; i$1++) {
                if (lineNo(lineView.rest[i$1]) > lineN) {
                    return { map: lineView.measure.maps[i$1], cache: lineView.measure.caches[i$1], before: true }
                }
            }
        }
    }

    // Render a line into the hidden node display.externalMeasured. Used
    // when measurement is needed for a line that's not in the viewport.
    function updateExternalMeasurement(cm, line) {
        line = visualLine(line)
        var lineN = lineNo(line)
        var view = (cm.display.externalMeasured = new LineView(cm.doc, line, lineN))
        view.lineN = lineN
        var built = (view.built = buildLineContent(cm, view))
        view.text = built.pre
        removeChildrenAndAdd(cm.display.lineMeasure, built.pre)
        return view
    }

    // Get a {top, bottom, left, right} box (in line-local coordinates)
    // for a given character.
    function measureChar(cm, line, ch, bias) {
        return measureCharPrepared(cm, prepareMeasureForLine(cm, line), ch, bias)
    }

    // Find a line view that corresponds to the given line number.
    function findViewForLine(cm, lineN) {
        if (lineN >= cm.display.viewFrom && lineN < cm.display.viewTo) {
            return cm.display.view[findViewIndex(cm, lineN)]
        }
        var ext = cm.display.externalMeasured
        if (ext && lineN >= ext.lineN && lineN < ext.lineN + ext.size) {
            return ext
        }
    }

    // Measurement can be split in two steps, the set-up work that
    // applies to the whole line, and the measurement of the actual
    // character. Functions like coordsChar, that need to do a lot of
    // measurements in a row, can thus ensure that the set-up work is
    // only done once.
    function prepareMeasureForLine(cm, line) {
        var lineN = lineNo(line)
        var view = findViewForLine(cm, lineN)
        if (view && !view.text) {
            view = null
        } else if (view && view.changes) {
            updateLineForChanges(cm, view, lineN, getDimensions(cm))
            cm.curOp.forceUpdate = true
        }
        if (!view) {
            view = updateExternalMeasurement(cm, line)
        }

        var info = mapFromLineView(view, line, lineN)
        return {
            line: line,
            view: view,
            rect: null,
            map: info.map,
            cache: info.cache,
            before: info.before,
            hasHeights: false,
        }
    }

    // Given a prepared measurement object, measures the position of an
    // actual character (or fetches it from the cache).
    function measureCharPrepared(cm, prepared, ch, bias, varHeight) {
        if (prepared.before) {
            ch = -1
        }
        var key = ch + (bias || ''),
            found
        if (prepared.cache.hasOwnProperty(key)) {
            found = prepared.cache[key]
        } else {
            if (!prepared.rect) {
                prepared.rect = prepared.view.text.getBoundingClientRect()
            }
            if (!prepared.hasHeights) {
                ensureLineHeights(cm, prepared.view, prepared.rect)
                prepared.hasHeights = true
            }
            found = measureCharInner(cm, prepared, ch, bias)
            if (!found.bogus) {
                prepared.cache[key] = found
            }
        }
        return { left: found.left, right: found.right, top: varHeight ? found.rtop : found.top, bottom: varHeight ? found.rbottom : found.bottom }
    }

    var nullRect = { left: 0, right: 0, top: 0, bottom: 0 }

    function nodeAndOffsetInLineMap(map, ch, bias) {
        var node, start, end, collapse, mStart, mEnd
        // First, search the line map for the text node corresponding to,
        // or closest to, the target character.
        for (var i = 0; i < map.length; i += 3) {
            mStart = map[i]
            mEnd = map[i + 1]
            if (ch < mStart) {
                start = 0
                end = 1
                collapse = 'left'
            } else if (ch < mEnd) {
                start = ch - mStart
                end = start + 1
            } else if (i == map.length - 3 || (ch == mEnd && map[i + 3] > ch)) {
                end = mEnd - mStart
                start = end - 1
                if (ch >= mEnd) {
                    collapse = 'right'
                }
            }
            if (start != null) {
                node = map[i + 2]
                if (mStart == mEnd && bias == (node.insertLeft ? 'left' : 'right')) {
                    collapse = bias
                }
                if (bias == 'left' && start == 0) {
                    while (i && map[i - 2] == map[i - 3] && map[i - 1].insertLeft) {
                        node = map[(i -= 3) + 2]
                        collapse = 'left'
                    }
                }
                if (bias == 'right' && start == mEnd - mStart) {
                    while (i < map.length - 3 && map[i + 3] == map[i + 4] && !map[i + 5].insertLeft) {
                        node = map[(i += 3) + 2]
                        collapse = 'right'
                    }
                }
                break
            }
        }
        return { node: node, start: start, end: end, collapse: collapse, coverStart: mStart, coverEnd: mEnd }
    }

    function getUsefulRect(rects, bias) {
        var rect = nullRect
        if (bias == 'left') {
            for (var i = 0; i < rects.length; i++) {
                if ((rect = rects[i]).left != rect.right) {
                    break
                }
            }
        } else {
            for (var i$1 = rects.length - 1; i$1 >= 0; i$1--) {
                if ((rect = rects[i$1]).left != rect.right) {
                    break
                }
            }
        }
        return rect
    }

    function measureCharInner(cm, prepared, ch, bias) {
        var place = nodeAndOffsetInLineMap(prepared.map, ch, bias)
        var node = place.node,
            start = place.start,
            end = place.end,
            collapse = place.collapse

        var rect
        if (node.nodeType == 3) {
            // If it is a text node, use a range to retrieve the coordinates.
            for (var i$1 = 0; i$1 < 4; i$1++) {
                // Retry a maximum of 4 times when nonsense rectangles are returned
                while (start && isExtendingChar(prepared.line.text.charAt(place.coverStart + start))) {
                    --start
                }
                while (place.coverStart + end < place.coverEnd && isExtendingChar(prepared.line.text.charAt(place.coverStart + end))) {
                    ++end
                }
                if (ie && ie_version < 9 && start == 0 && end == place.coverEnd - place.coverStart) {
                    rect = node.parentNode.getBoundingClientRect()
                } else {
                    rect = getUsefulRect(range(node, start, end).getClientRects(), bias)
                }
                if (rect.left || rect.right || start == 0) {
                    break
                }
                end = start
                start = start - 1
                collapse = 'right'
            }
            if (ie && ie_version < 11) {
                rect = maybeUpdateRectForZooming(cm.display.measure, rect)
            }
        } else {
            // If it is a widget, simply get the box for the whole widget.
            if (start > 0) {
                collapse = bias = 'right'
            }
            var rects
            if (cm.options.lineWrapping && (rects = node.getClientRects()).length > 1) {
                rect = rects[bias == 'right' ? rects.length - 1 : 0]
            } else {
                rect = node.getBoundingClientRect()
            }
        }
        if (ie && ie_version < 9 && !start && (!rect || (!rect.left && !rect.right))) {
            var rSpan = node.parentNode.getClientRects()[0]
            if (rSpan) {
                rect = { left: rSpan.left, right: rSpan.left + charWidth(cm.display), top: rSpan.top, bottom: rSpan.bottom }
            } else {
                rect = nullRect
            }
        }

        var rtop = rect.top - prepared.rect.top,
            rbot = rect.bottom - prepared.rect.top
        var mid = (rtop + rbot) / 2
        var heights = prepared.view.measure.heights
        var i = 0
        for (; i < heights.length - 1; i++) {
            if (mid < heights[i]) {
                break
            }
        }
        var top = i ? heights[i - 1] : 0,
            bot = heights[i]
        var result = { left: (collapse == 'right' ? rect.right : rect.left) - prepared.rect.left, right: (collapse == 'left' ? rect.left : rect.right) - prepared.rect.left, top: top, bottom: bot }
        if (!rect.left && !rect.right) {
            result.bogus = true
        }
        if (!cm.options.singleCursorHeightPerLine) {
            result.rtop = rtop
            result.rbottom = rbot
        }

        return result
    }

    // Work around problem with bounding client rects on ranges being
    // returned incorrectly when zoomed on IE10 and below.
    function maybeUpdateRectForZooming(measure, rect) {
        if (!window.screen || screen.logicalXDPI == null || screen.logicalXDPI == screen.deviceXDPI || !hasBadZoomedRects(measure)) {
            return rect
        }
        var scaleX = screen.logicalXDPI / screen.deviceXDPI
        var scaleY = screen.logicalYDPI / screen.deviceYDPI
        return { left: rect.left * scaleX, right: rect.right * scaleX, top: rect.top * scaleY, bottom: rect.bottom * scaleY }
    }

    function clearLineMeasurementCacheFor(lineView) {
        if (lineView.measure) {
            lineView.measure.cache = {}
            lineView.measure.heights = null
            if (lineView.rest) {
                for (var i = 0; i < lineView.rest.length; i++) {
                    lineView.measure.caches[i] = {}
                }
            }
        }
    }

    function clearLineMeasurementCache(cm) {
        cm.display.externalMeasure = null
        removeChildren(cm.display.lineMeasure)
        for (var i = 0; i < cm.display.view.length; i++) {
            clearLineMeasurementCacheFor(cm.display.view[i])
        }
    }

    function clearCaches(cm) {
        clearLineMeasurementCache(cm)
        cm.display.cachedCharWidth = cm.display.cachedTextHeight = cm.display.cachedPaddingH = null
        if (!cm.options.lineWrapping) {
            cm.display.maxLineChanged = true
        }
        cm.display.lineNumChars = null
    }

    function pageScrollX() {
        // Work around https://bugs.chromium.org/p/chromium/issues/detail?id=489206
        // which causes page_Offset and bounding client rects to use
        // different reference viewports and invalidate our calculations.
        if (chrome && android) {
            return -(document.body.getBoundingClientRect().left - parseInt(getComputedStyle(document.body).marginLeft))
        }
        return window.pageXOffset || (document.documentElement || document.body).scrollLeft
    }
    function pageScrollY() {
        if (chrome && android) {
            return -(document.body.getBoundingClientRect().top - parseInt(getComputedStyle(document.body).marginTop))
        }
        return window.pageYOffset || (document.documentElement || document.body).scrollTop
    }

    function widgetTopHeight(lineObj) {
        var ref = visualLine(lineObj)
        var widgets = ref.widgets
        var height = 0
        if (widgets) {
            for (var i = 0; i < widgets.length; ++i) {
                if (widgets[i].above) {
                    height += widgetHeight(widgets[i])
                }
            }
        }
        return height
    }

    // Converts a {top, bottom, left, right} box from line-local
    // coordinates into another coordinate system. Context may be one of
    // "line", "div" (display.lineDiv), "local"./null (editor), "window",
    // or "page".
    function intoCoordSystem(cm, lineObj, rect, context, includeWidgets) {
        if (!includeWidgets) {
            var height = widgetTopHeight(lineObj)
            rect.top += height
            rect.bottom += height
        }
        if (context == 'line') {
            return rect
        }
        if (!context) {
            context = 'local'
        }
        var yOff = heightAtLine(lineObj)
        if (context == 'local') {
            yOff += paddingTop(cm.display)
        } else {
            yOff -= cm.display.viewOffset
        }
        if (context == 'page' || context == 'window') {
            var lOff = cm.display.lineSpace.getBoundingClientRect()
            yOff += lOff.top + (context == 'window' ? 0 : pageScrollY())
            var xOff = lOff.left + (context == 'window' ? 0 : pageScrollX())
            rect.left += xOff
            rect.right += xOff
        }
        rect.top += yOff
        rect.bottom += yOff
        return rect
    }

    // Coverts a box from "div" coords to another coordinate system.
    // Context may be "window", "page", "div", or "local"./null.
    function fromCoordSystem(cm, coords, context) {
        if (context == 'div') {
            return coords
        }
        var left = coords.left,
            top = coords.top
        // First move into "page" coordinate system
        if (context == 'page') {
            left -= pageScrollX()
            top -= pageScrollY()
        } else if (context == 'local' || !context) {
            var localBox = cm.display.sizer.getBoundingClientRect()
            left += localBox.left
            top += localBox.top
        }

        var lineSpaceBox = cm.display.lineSpace.getBoundingClientRect()
        return { left: left - lineSpaceBox.left, top: top - lineSpaceBox.top }
    }

    function charCoords(cm, pos, context, lineObj, bias) {
        if (!lineObj) {
            lineObj = getLine(cm.doc, pos.line)
        }
        return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, bias), context)
    }

    // Returns a box for a given cursor position, which may have an
    // 'other' property containing the position of the secondary cursor
    // on a bidi boundary.
    // A cursor Pos(line, char, "before") is on the same visual line as `char - 1`
    // and after `char - 1` in writing order of `char - 1`
    // A cursor Pos(line, char, "after") is on the same visual line as `char`
    // and before `char` in writing order of `char`
    // Examples (upper-case letters are RTL, lower-case are LTR):
    //     Pos(0, 1, ...)
    //     before   after
    // ab     a|b     a|b
    // aB     a|B     aB|
    // Ab     |Ab     A|b
    // AB     B|A     B|A
    // Every position after the last character on a line is considered to stick
    // to the last character on the line.
    function cursorCoords(cm, pos, context, lineObj, preparedMeasure, varHeight) {
        lineObj = lineObj || getLine(cm.doc, pos.line)
        if (!preparedMeasure) {
            preparedMeasure = prepareMeasureForLine(cm, lineObj)
        }
        function get(ch, right) {
            var m = measureCharPrepared(cm, preparedMeasure, ch, right ? 'right' : 'left', varHeight)
            if (right) {
                m.left = m.right
            } else {
                m.right = m.left
            }
            return intoCoordSystem(cm, lineObj, m, context)
        }
        var order = getOrder(lineObj, cm.doc.direction),
            ch = pos.ch,
            sticky = pos.sticky
        if (ch >= lineObj.text.length) {
            ch = lineObj.text.length
            sticky = 'before'
        } else if (ch <= 0) {
            ch = 0
            sticky = 'after'
        }
        if (!order) {
            return get(sticky == 'before' ? ch - 1 : ch, sticky == 'before')
        }

        function getBidi(ch, partPos, invert) {
            var part = order[partPos],
                right = part.level == 1
            return get(invert ? ch - 1 : ch, right != invert)
        }
        var partPos = getBidiPartAt(order, ch, sticky)
        var other = bidiOther
        var val = getBidi(ch, partPos, sticky == 'before')
        if (other != null) {
            val.other = getBidi(ch, other, sticky != 'before')
        }
        return val
    }

    // Used to cheaply estimate the coordinates for a position. Used for
    // intermediate scroll updates.
    function estimateCoords(cm, pos) {
        var left = 0
        pos = clipPos(cm.doc, pos)
        if (!cm.options.lineWrapping) {
            left = charWidth(cm.display) * pos.ch
        }
        var lineObj = getLine(cm.doc, pos.line)
        var top = heightAtLine(lineObj) + paddingTop(cm.display)
        return { left: left, right: left, top: top, bottom: top + lineObj.height }
    }

    // Positions returned by coordsChar contain some extra information.
    // xRel is the relative x position of the input coordinates compared
    // to the found position (so xRel > 0 means the coordinates are to
    // the right of the character position, for example). When outside
    // is true, that means the coordinates lie outside the line's
    // vertical range.
    function PosWithInfo(line, ch, sticky, outside, xRel) {
        var pos = Pos(line, ch, sticky)
        pos.xRel = xRel
        if (outside) {
            pos.outside = outside
        }
        return pos
    }

    // Compute the character position closest to the given coordinates.
    // Input must be lineSpace-local ("div" coordinate system).
    function coordsChar(cm, x, y) {
        var doc = cm.doc
        y += cm.display.viewOffset
        if (y < 0) {
            return PosWithInfo(doc.first, 0, null, -1, -1)
        }
        var lineN = lineAtHeight(doc, y),
            last = doc.first + doc.size - 1
        if (lineN > last) {
            return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, null, 1, 1)
        }
        if (x < 0) {
            x = 0
        }

        var lineObj = getLine(doc, lineN)
        for (;;) {
            var found = coordsCharInner(cm, lineObj, lineN, x, y)
            var collapsed = collapsedSpanAround(lineObj, found.ch + (found.xRel > 0 || found.outside > 0 ? 1 : 0))
            if (!collapsed) {
                return found
            }
            var rangeEnd = collapsed.find(1)
            if (rangeEnd.line == lineN) {
                return rangeEnd
            }
            lineObj = getLine(doc, (lineN = rangeEnd.line))
        }
    }

    function wrappedLineExtent(cm, lineObj, preparedMeasure, y) {
        y -= widgetTopHeight(lineObj)
        var end = lineObj.text.length
        var begin = findFirst(
            function (ch) {
                return measureCharPrepared(cm, preparedMeasure, ch - 1).bottom <= y
            },
            end,
            0
        )
        end = findFirst(
            function (ch) {
                return measureCharPrepared(cm, preparedMeasure, ch).top > y
            },
            begin,
            end
        )
        return { begin: begin, end: end }
    }

    function wrappedLineExtentChar(cm, lineObj, preparedMeasure, target) {
        if (!preparedMeasure) {
            preparedMeasure = prepareMeasureForLine(cm, lineObj)
        }
        var targetTop = intoCoordSystem(cm, lineObj, measureCharPrepared(cm, preparedMeasure, target), 'line').top
        return wrappedLineExtent(cm, lineObj, preparedMeasure, targetTop)
    }

    // Returns true if the given side of a box is after the given
    // coordinates, in top-to-bottom, left-to-right order.
    function boxIsAfter(box, x, y, left) {
        return box.bottom <= y ? false : box.top > y ? true : (left ? box.left : box.right) > x
    }

    function coordsCharInner(cm, lineObj, lineNo, x, y) {
        // Move y into line-local coordinate space
        y -= heightAtLine(lineObj)
        var preparedMeasure = prepareMeasureForLine(cm, lineObj)
        // When directly calling `measureCharPrepared`, we have to adjust
        // for the widgets at this line.
        var widgetHeight = widgetTopHeight(lineObj)
        var begin = 0,
            end = lineObj.text.length,
            ltr = true

        var order = getOrder(lineObj, cm.doc.direction)
        // If the line isn't plain left-to-right text, first figure out
        // which bidi section the coordinates fall into.
        if (order) {
            var part = (cm.options.lineWrapping ? coordsBidiPartWrapped : coordsBidiPart)(cm, lineObj, lineNo, preparedMeasure, order, x, y)
            ltr = part.level != 1
            // The awkward -1 offsets are needed because findFirst (called
            // on these below) will treat its first bound as inclusive,
            // second as exclusive, but we want to actually address the
            // characters in the part's range
            begin = ltr ? part.from : part.to - 1
            end = ltr ? part.to : part.from - 1
        }

        // A binary search to find the first character whose bounding box
        // starts after the coordinates. If we run across any whose box wrap
        // the coordinates, store that.
        var chAround = null,
            boxAround = null
        var ch = findFirst(
            function (ch) {
                var box = measureCharPrepared(cm, preparedMeasure, ch)
                box.top += widgetHeight
                box.bottom += widgetHeight
                if (!boxIsAfter(box, x, y, false)) {
                    return false
                }
                if (box.top <= y && box.left <= x) {
                    chAround = ch
                    boxAround = box
                }
                return true
            },
            begin,
            end
        )

        var baseX,
            sticky,
            outside = false
        // If a box around the coordinates was found, use that
        if (boxAround) {
            // Distinguish coordinates nearer to the left or right side of the box
            var atLeft = x - boxAround.left < boxAround.right - x,
                atStart = atLeft == ltr
            ch = chAround + (atStart ? 0 : 1)
            sticky = atStart ? 'after' : 'before'
            baseX = atLeft ? boxAround.left : boxAround.right
        } else {
            // (Adjust for extended bound, if necessary.)
            if (!ltr && (ch == end || ch == begin)) {
                ch++
            }
            // To determine which side to associate with, get the box to the
            // left of the character and compare it's vertical position to the
            // coordinates
            sticky = ch == 0 ? 'after' : ch == lineObj.text.length ? 'before' : measureCharPrepared(cm, preparedMeasure, ch - (ltr ? 1 : 0)).bottom + widgetHeight <= y == ltr ? 'after' : 'before'
            // Now get accurate coordinates for this place, in order to get a
            // base X position
            var coords = cursorCoords(cm, Pos(lineNo, ch, sticky), 'line', lineObj, preparedMeasure)
            baseX = coords.left
            outside = y < coords.top ? -1 : y >= coords.bottom ? 1 : 0
        }

        ch = skipExtendingChars(lineObj.text, ch, 1)
        return PosWithInfo(lineNo, ch, sticky, outside, x - baseX)
    }

    function coordsBidiPart(cm, lineObj, lineNo, preparedMeasure, order, x, y) {
        // Bidi parts are sorted left-to-right, and in a non-line-wrapping
        // situation, we can take this ordering to correspond to the visual
        // ordering. This finds the first part whose end is after the given
        // coordinates.
        var index = findFirst(
            function (i) {
                var part = order[i],
                    ltr = part.level != 1
                return boxIsAfter(cursorCoords(cm, Pos(lineNo, ltr ? part.to : part.from, ltr ? 'before' : 'after'), 'line', lineObj, preparedMeasure), x, y, true)
            },
            0,
            order.length - 1
        )
        var part = order[index]
        // If this isn't the first part, the part's start is also after
        // the coordinates, and the coordinates aren't on the same line as
        // that start, move one part back.
        if (index > 0) {
            var ltr = part.level != 1
            var start = cursorCoords(cm, Pos(lineNo, ltr ? part.from : part.to, ltr ? 'after' : 'before'), 'line', lineObj, preparedMeasure)
            if (boxIsAfter(start, x, y, true) && start.top > y) {
                part = order[index - 1]
            }
        }
        return part
    }

    function coordsBidiPartWrapped(cm, lineObj, _lineNo, preparedMeasure, order, x, y) {
        // In a wrapped line, rtl text on wrapping boundaries can do things
        // that don't correspond to the ordering in our `order` array at
        // all, so a binary search doesn't work, and we want to return a
        // part that only spans one line so that the binary search in
        // coordsCharInner is safe. As such, we first find the extent of the
        // wrapped line, and then do a flat search in which we discard any
        // spans that aren't on the line.
        var ref = wrappedLineExtent(cm, lineObj, preparedMeasure, y)
        var begin = ref.begin
        var end = ref.end
        if (/\s/.test(lineObj.text.charAt(end - 1))) {
            end--
        }
        var part = null,
            closestDist = null
        for (var i = 0; i < order.length; i++) {
            var p = order[i]
            if (p.from >= end || p.to <= begin) {
                continue
            }
            var ltr = p.level != 1
            var endX = measureCharPrepared(cm, preparedMeasure, ltr ? Math.min(end, p.to) - 1 : Math.max(begin, p.from)).right
            // Weigh against spans ending before this, so that they are only
            // picked if nothing ends after
            var dist = endX < x ? x - endX + 1e9 : endX - x
            if (!part || closestDist > dist) {
                part = p
                closestDist = dist
            }
        }
        if (!part) {
            part = order[order.length - 1]
        }
        // Clip the part to the wrapped line.
        if (part.from < begin) {
            part = { from: begin, to: part.to, level: part.level }
        }
        if (part.to > end) {
            part = { from: part.from, to: end, level: part.level }
        }
        return part
    }

    var measureText
    // Compute the default text height.
    function textHeight(display) {
        if (display.cachedTextHeight != null) {
            return display.cachedTextHeight
        }
        if (measureText == null) {
            measureText = elt('pre', null, 'CodeMirror-line-like')
            // Measure a bunch of lines, for browsers that compute
            // fractional heights.
            for (var i = 0; i < 49; ++i) {
                measureText.appendChild(document.createTextNode('x'))
                measureText.appendChild(elt('br'))
            }
            measureText.appendChild(document.createTextNode('x'))
        }
        removeChildrenAndAdd(display.measure, measureText)
        var height = measureText.offsetHeight / 50
        if (height > 3) {
            display.cachedTextHeight = height
        }
        removeChildren(display.measure)
        return height || 1
    }

    // Compute the default character width.
    function charWidth(display) {
        if (display.cachedCharWidth != null) {
            return display.cachedCharWidth
        }
        var anchor = elt('span', 'xxxxxxxxxx')
        var pre = elt('pre', [anchor], 'CodeMirror-line-like')
        removeChildrenAndAdd(display.measure, pre)
        var rect = anchor.getBoundingClientRect(),
            width = (rect.right - rect.left) / 10
        if (width > 2) {
            display.cachedCharWidth = width
        }
        return width || 10
    }

    // Do a bulk-read of the DOM positions and sizes needed to draw the
    // view, so that we don't interleave reading and writing to the DOM.
    function getDimensions(cm) {
        var d = cm.display,
            left = {},
            width = {}
        var gutterLeft = d.gutters.clientLeft
        for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
            var id = cm.display.gutterSpecs[i].className
            left[id] = n.offsetLeft + n.clientLeft + gutterLeft
            width[id] = n.clientWidth
        }
        return { fixedPos: compensateForHScroll(d), gutterTotalWidth: d.gutters.offsetWidth, gutterLeft: left, gutterWidth: width, wrapperWidth: d.wrapper.clientWidth }
    }

    // Computes display.scroller.scrollLeft + display.gutters.offsetWidth,
    // but using getBoundingClientRect to get a sub-pixel-accurate
    // result.
    function compensateForHScroll(display) {
        return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left
    }

    // Returns a function that estimates the height of a line, to use as
    // first approximation until the line becomes visible (and is thus
    // properly measurable).
    function estimateHeight(cm) {
        var th = textHeight(cm.display),
            wrapping = cm.options.lineWrapping
        var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3)
        return function (line) {
            if (lineIsHidden(cm.doc, line)) {
                return 0
            }

            var widgetsHeight = 0
            if (line.widgets) {
                for (var i = 0; i < line.widgets.length; i++) {
                    if (line.widgets[i].height) {
                        widgetsHeight += line.widgets[i].height
                    }
                }
            }

            if (wrapping) {
                return widgetsHeight + (Math.ceil(line.text.length / perLine) || 1) * th
            } else {
                return widgetsHeight + th
            }
        }
    }

    function estimateLineHeights(cm) {
        var doc = cm.doc,
            est = estimateHeight(cm)
        doc.iter(function (line) {
            var estHeight = est(line)
            if (estHeight != line.height) {
                updateLineHeight(line, estHeight)
            }
        })
    }

    // Given a mouse event, find the corresponding position. If liberal
    // is false, it checks whether a gutter or scrollbar was clicked,
    // and returns null if it was. forRect is used by rectangular
    // selections, and tries to estimate a character position even for
    // coordinates beyond the right of the text.
    function posFromMouse(cm, e, liberal, forRect) {
        var display = cm.display
        if (!liberal && e_target(e).getAttribute('cm-not-content') == 'true') {
            return null
        }

        var x,
            y,
            space = display.lineSpace.getBoundingClientRect()
        // Fails unpredictably on IE[67] when mouse is dragged around quickly.
        try {
            x = e.clientX - space.left
            y = e.clientY - space.top
        } catch (e$1) {
            return null
        }
        var coords = coordsChar(cm, x, y),
            line
        if (forRect && coords.xRel > 0 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {
            var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length
            coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff))
        }
        return coords
    }

    // Find the view element corresponding to a given line. Return null
    // when the line isn't visible.
    function findViewIndex(cm, n) {
        if (n >= cm.display.viewTo) {
            return null
        }
        n -= cm.display.viewFrom
        if (n < 0) {
            return null
        }
        var view = cm.display.view
        for (var i = 0; i < view.length; i++) {
            n -= view[i].size
            if (n < 0) {
                return i
            }
        }
    }

    // Updates the display.view data structure for a given change to the
    // document. From and to are in pre-change coordinates. Lendiff is
    // the amount of lines added or subtracted by the change. This is
    // used for changes that span multiple lines, or change the way
    // lines are divided into visual lines. regLineChange (below)
    // registers single-line changes.
    function regChange(cm, from, to, lendiff) {
        if (from == null) {
            from = cm.doc.first
        }
        if (to == null) {
            to = cm.doc.first + cm.doc.size
        }
        if (!lendiff) {
            lendiff = 0
        }

        var display = cm.display
        if (lendiff && to < display.viewTo && (display.updateLineNumbers == null || display.updateLineNumbers > from)) {
            display.updateLineNumbers = from
        }

        cm.curOp.viewChanged = true

        if (from >= display.viewTo) {
            // Change after
            if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo) {
                resetView(cm)
            }
        } else if (to <= display.viewFrom) {
            // Change before
            if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
                resetView(cm)
            } else {
                display.viewFrom += lendiff
                display.viewTo += lendiff
            }
        } else if (from <= display.viewFrom && to >= display.viewTo) {
            // Full overlap
            resetView(cm)
        } else if (from <= display.viewFrom) {
            // Top overlap
            var cut = viewCuttingPoint(cm, to, to + lendiff, 1)
            if (cut) {
                display.view = display.view.slice(cut.index)
                display.viewFrom = cut.lineN
                display.viewTo += lendiff
            } else {
                resetView(cm)
            }
        } else if (to >= display.viewTo) {
            // Bottom overlap
            var cut$1 = viewCuttingPoint(cm, from, from, -1)
            if (cut$1) {
                display.view = display.view.slice(0, cut$1.index)
                display.viewTo = cut$1.lineN
            } else {
                resetView(cm)
            }
        } else {
            // Gap in the middle
            var cutTop = viewCuttingPoint(cm, from, from, -1)
            var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1)
            if (cutTop && cutBot) {
                display.view = display.view.slice(0, cutTop.index).concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN)).concat(display.view.slice(cutBot.index))
                display.viewTo += lendiff
            } else {
                resetView(cm)
            }
        }

        var ext = display.externalMeasured
        if (ext) {
            if (to < ext.lineN) {
                ext.lineN += lendiff
            } else if (from < ext.lineN + ext.size) {
                display.externalMeasured = null
            }
        }
    }

    // Register a change to a single line. Type must be one of "text",
    // "gutter", "class", "widget"
    function regLineChange(cm, line, type) {
        cm.curOp.viewChanged = true
        var display = cm.display,
            ext = cm.display.externalMeasured
        if (ext && line >= ext.lineN && line < ext.lineN + ext.size) {
            display.externalMeasured = null
        }

        if (line < display.viewFrom || line >= display.viewTo) {
            return
        }
        var lineView = display.view[findViewIndex(cm, line)]
        if (lineView.node == null) {
            return
        }
        var arr = lineView.changes || (lineView.changes = [])
        if (indexOf(arr, type) == -1) {
            arr.push(type)
        }
    }

    // Clear the view.
    function resetView(cm) {
        cm.display.viewFrom = cm.display.viewTo = cm.doc.first
        cm.display.view = []
        cm.display.viewOffset = 0
    }

    function viewCuttingPoint(cm, oldN, newN, dir) {
        var index = findViewIndex(cm, oldN),
            diff,
            view = cm.display.view
        if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size) {
            return { index: index, lineN: newN }
        }
        var n = cm.display.viewFrom
        for (var i = 0; i < index; i++) {
            n += view[i].size
        }
        if (n != oldN) {
            if (dir > 0) {
                if (index == view.length - 1) {
                    return null
                }
                diff = n + view[index].size - oldN
                index++
            } else {
                diff = n - oldN
            }
            oldN += diff
            newN += diff
        }
        while (visualLineNo(cm.doc, newN) != newN) {
            if (index == (dir < 0 ? 0 : view.length - 1)) {
                return null
            }
            newN += dir * view[index - (dir < 0 ? 1 : 0)].size
            index += dir
        }
        return { index: index, lineN: newN }
    }

    // Force the view to cover a given range, adding empty view element
    // or clipping off existing ones as needed.
    function adjustView(cm, from, to) {
        var display = cm.display,
            view = display.view
        if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
            display.view = buildViewArray(cm, from, to)
            display.viewFrom = from
        } else {
            if (display.viewFrom > from) {
                display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view)
            } else if (display.viewFrom < from) {
                display.view = display.view.slice(findViewIndex(cm, from))
            }
            display.viewFrom = from
            if (display.viewTo < to) {
                display.view = display.view.concat(buildViewArray(cm, display.viewTo, to))
            } else if (display.viewTo > to) {
                display.view = display.view.slice(0, findViewIndex(cm, to))
            }
        }
        display.viewTo = to
    }

    // Count the number of lines in the view whose DOM representation is
    // out of date (or nonexistent).
    function countDirtyView(cm) {
        var view = cm.display.view,
            dirty = 0
        for (var i = 0; i < view.length; i++) {
            var lineView = view[i]
            if (!lineView.hidden && (!lineView.node || lineView.changes)) {
                ++dirty
            }
        }
        return dirty
    }

    function updateSelection(cm) {
        cm.display.input.showSelection(cm.display.input.prepareSelection())
    }

    function prepareSelection(cm, primary) {
        if (primary === void 0) primary = true

        var doc = cm.doc,
            result = {}
        var curFragment = (result.cursors = document.createDocumentFragment())
        var selFragment = (result.selection = document.createDocumentFragment())

        var customCursor = cm.options.$customCursor
        if (customCursor) {
            primary = true
        }
        for (var i = 0; i < doc.sel.ranges.length; i++) {
            if (!primary && i == doc.sel.primIndex) {
                continue
            }
            var range = doc.sel.ranges[i]
            if (range.from().line >= cm.display.viewTo || range.to().line < cm.display.viewFrom) {
                continue
            }
            var collapsed = range.empty()
            if (customCursor) {
                var head = customCursor(cm, range)
                if (head) {
                    drawSelectionCursor(cm, head, curFragment)
                }
            } else if (collapsed || cm.options.showCursorWhenSelecting) {
                drawSelectionCursor(cm, range.head, curFragment)
            }
            if (!collapsed) {
                drawSelectionRange(cm, range, selFragment)
            }
        }
        return result
    }

    // Draws a cursor for the given range
    function drawSelectionCursor(cm, head, output) {
        var pos = cursorCoords(cm, head, 'div', null, null, !cm.options.singleCursorHeightPerLine)

        var cursor = output.appendChild(elt('div', '\u00a0', 'CodeMirror-cursor'))
        cursor.style.left = pos.left + 'px'
        cursor.style.top = pos.top + 'px'
        cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + 'px'

        if (/\bcm-fat-cursor\b/.test(cm.getWrapperElement().className)) {
            var charPos = charCoords(cm, head, 'div', null, null)
            var width = charPos.right - charPos.left
            cursor.style.width = (width > 0 ? width : cm.defaultCharWidth()) + 'px'
        }

        if (pos.other) {
            // Secondary cursor, shown when on a 'jump' in bi-directional text
            var otherCursor = output.appendChild(elt('div', '\u00a0', 'CodeMirror-cursor CodeMirror-secondarycursor'))
            otherCursor.style.display = ''
            otherCursor.style.left = pos.other.left + 'px'
            otherCursor.style.top = pos.other.top + 'px'
            otherCursor.style.height = (pos.other.bottom - pos.other.top) * 0.85 + 'px'
        }
    }

    function cmpCoords(a, b) {
        return a.top - b.top || a.left - b.left
    }

    // Draws the given range as a highlighted selection
    function drawSelectionRange(cm, range, output) {
        var display = cm.display,
            doc = cm.doc
        var fragment = document.createDocumentFragment()
        var padding = paddingH(cm.display),
            leftSide = padding.left
        var rightSide = Math.max(display.sizerWidth, displayWidth(cm) - display.sizer.offsetLeft) - padding.right
        var docLTR = doc.direction == 'ltr'

        function add(left, top, width, bottom) {
            if (top < 0) {
                top = 0
            }
            top = Math.round(top)
            bottom = Math.round(bottom)
            fragment.appendChild(
                elt(
                    'div',
                    null,
                    'CodeMirror-selected',
                    'position: absolute; left: ' +
                        left +
                        'px;\n                             top: ' +
                        top +
                        'px; width: ' +
                        (width == null ? rightSide - left : width) +
                        'px;\n                             height: ' +
                        (bottom - top) +
                        'px'
                )
            )
        }

        function drawForLine(line, fromArg, toArg) {
            var lineObj = getLine(doc, line)
            var lineLen = lineObj.text.length
            var start, end
            function coords(ch, bias) {
                return charCoords(cm, Pos(line, ch), 'div', lineObj, bias)
            }

            function wrapX(pos, dir, side) {
                var extent = wrappedLineExtentChar(cm, lineObj, null, pos)
                var prop = (dir == 'ltr') == (side == 'after') ? 'left' : 'right'
                var ch = side == 'after' ? extent.begin : extent.end - (/\s/.test(lineObj.text.charAt(extent.end - 1)) ? 2 : 1)
                return coords(ch, prop)[prop]
            }

            var order = getOrder(lineObj, doc.direction)
            iterateBidiSections(order, fromArg || 0, toArg == null ? lineLen : toArg, function (from, to, dir, i) {
                var ltr = dir == 'ltr'
                var fromPos = coords(from, ltr ? 'left' : 'right')
                var toPos = coords(to - 1, ltr ? 'right' : 'left')

                var openStart = fromArg == null && from == 0,
                    openEnd = toArg == null && to == lineLen
                var first = i == 0,
                    last = !order || i == order.length - 1
                if (toPos.top - fromPos.top <= 3) {
                    // Single line
                    var openLeft = (docLTR ? openStart : openEnd) && first
                    var openRight = (docLTR ? openEnd : openStart) && last
                    var left = openLeft ? leftSide : (ltr ? fromPos : toPos).left
                    var right = openRight ? rightSide : (ltr ? toPos : fromPos).right
                    add(left, fromPos.top, right - left, fromPos.bottom)
                } else {
                    // Multiple lines
                    var topLeft, topRight, botLeft, botRight
                    if (ltr) {
                        topLeft = docLTR && openStart && first ? leftSide : fromPos.left
                        topRight = docLTR ? rightSide : wrapX(from, dir, 'before')
                        botLeft = docLTR ? leftSide : wrapX(to, dir, 'after')
                        botRight = docLTR && openEnd && last ? rightSide : toPos.right
                    } else {
                        topLeft = !docLTR ? leftSide : wrapX(from, dir, 'before')
                        topRight = !docLTR && openStart && first ? rightSide : fromPos.right
                        botLeft = !docLTR && openEnd && last ? leftSide : toPos.left
                        botRight = !docLTR ? rightSide : wrapX(to, dir, 'after')
                    }
                    add(topLeft, fromPos.top, topRight - topLeft, fromPos.bottom)
                    if (fromPos.bottom < toPos.top) {
                        add(leftSide, fromPos.bottom, null, toPos.top)
                    }
                    add(botLeft, toPos.top, botRight - botLeft, toPos.bottom)
                }

                if (!start || cmpCoords(fromPos, start) < 0) {
                    start = fromPos
                }
                if (cmpCoords(toPos, start) < 0) {
                    start = toPos
                }
                if (!end || cmpCoords(fromPos, end) < 0) {
                    end = fromPos
                }
                if (cmpCoords(toPos, end) < 0) {
                    end = toPos
                }
            })
            return { start: start, end: end }
        }

        var sFrom = range.from(),
            sTo = range.to()
        if (sFrom.line == sTo.line) {
            drawForLine(sFrom.line, sFrom.ch, sTo.ch)
        } else {
            var fromLine = getLine(doc, sFrom.line),
                toLine = getLine(doc, sTo.line)
            var singleVLine = visualLine(fromLine) == visualLine(toLine)
            var leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end
            var rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start
            if (singleVLine) {
                if (leftEnd.top < rightStart.top - 2) {
                    add(leftEnd.right, leftEnd.top, null, leftEnd.bottom)
                    add(leftSide, rightStart.top, rightStart.left, rightStart.bottom)
                } else {
                    add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom)
                }
            }
            if (leftEnd.bottom < rightStart.top) {
                add(leftSide, leftEnd.bottom, null, rightStart.top)
            }
        }

        output.appendChild(fragment)
    }

    // Cursor-blinking
    function restartBlink(cm) {
        if (!cm.state.focused) {
            return
        }
        var display = cm.display
        clearInterval(display.blinker)
        var on = true
        display.cursorDiv.style.visibility = ''
        if (cm.options.cursorBlinkRate > 0) {
            display.blinker = setInterval(function () {
                if (!cm.hasFocus()) {
                    onBlur(cm)
                }
                display.cursorDiv.style.visibility = (on = !on) ? '' : 'hidden'
            }, cm.options.cursorBlinkRate)
        } else if (cm.options.cursorBlinkRate < 0) {
            display.cursorDiv.style.visibility = 'hidden'
        }
    }

    function ensureFocus(cm) {
        if (!cm.hasFocus()) {
            cm.display.input.focus()
            if (!cm.state.focused) {
                onFocus(cm)
            }
        }
    }

    function delayBlurEvent(cm) {
        cm.state.delayingBlurEvent = true
        setTimeout(function () {
            if (cm.state.delayingBlurEvent) {
                cm.state.delayingBlurEvent = false
                if (cm.state.focused) {
                    onBlur(cm)
                }
            }
        }, 100)
    }

    function onFocus(cm, e) {
        if (cm.state.delayingBlurEvent && !cm.state.draggingText) {
            cm.state.delayingBlurEvent = false
        }

        if (cm.options.readOnly == 'nocursor') {
            return
        }
        if (!cm.state.focused) {
            signal(cm, 'focus', cm, e)
            cm.state.focused = true
            addClass(cm.display.wrapper, 'CodeMirror-focused')
            // This test prevents this from firing when a context
            // menu is closed (since the input reset would kill the
            // select-all detection hack)
            if (!cm.curOp && cm.display.selForContextMenu != cm.doc.sel) {
                cm.display.input.reset()
                if (webkit) {
                    setTimeout(function () {
                        return cm.display.input.reset(true)
                    }, 20)
                } // Issue #1730
            }
            cm.display.input.receivedFocus()
        }
        restartBlink(cm)
    }
    function onBlur(cm, e) {
        if (cm.state.delayingBlurEvent) {
            return
        }

        if (cm.state.focused) {
            signal(cm, 'blur', cm, e)
            cm.state.focused = false
            rmClass(cm.display.wrapper, 'CodeMirror-focused')
        }
        clearInterval(cm.display.blinker)
        setTimeout(function () {
            if (!cm.state.focused) {
                cm.display.shift = false
            }
        }, 150)
    }

    // Read the actual heights of the rendered lines, and update their
    // stored heights to match.
    function updateHeightsInViewport(cm) {
        var display = cm.display
        var prevBottom = display.lineDiv.offsetTop
        var viewTop = Math.max(0, display.scroller.getBoundingClientRect().top)
        var oldHeight = display.lineDiv.getBoundingClientRect().top
        var mustScroll = 0
        for (var i = 0; i < display.view.length; i++) {
            var cur = display.view[i],
                wrapping = cm.options.lineWrapping
            var height = void 0,
                width = 0
            if (cur.hidden) {
                continue
            }
            oldHeight += cur.line.height
            if (ie && ie_version < 8) {
                var bot = cur.node.offsetTop + cur.node.offsetHeight
                height = bot - prevBottom
                prevBottom = bot
            } else {
                var box = cur.node.getBoundingClientRect()
                height = box.bottom - box.top
                // Check that lines don't extend past the right of the current
                // editor width
                if (!wrapping && cur.text.firstChild) {
                    width = cur.text.firstChild.getBoundingClientRect().right - box.left - 1
                }
            }
            var diff = cur.line.height - height
            if (diff > 0.005 || diff < -0.005) {
                if (oldHeight < viewTop) {
                    mustScroll -= diff
                }
                updateLineHeight(cur.line, height)
                updateWidgetHeight(cur.line)
                if (cur.rest) {
                    for (var j = 0; j < cur.rest.length; j++) {
                        updateWidgetHeight(cur.rest[j])
                    }
                }
            }
            if (width > cm.display.sizerWidth) {
                var chWidth = Math.ceil(width / charWidth(cm.display))
                if (chWidth > cm.display.maxLineLength) {
                    cm.display.maxLineLength = chWidth
                    cm.display.maxLine = cur.line
                    cm.display.maxLineChanged = true
                }
            }
        }
        if (Math.abs(mustScroll) > 2) {
            display.scroller.scrollTop += mustScroll
        }
    }

    // Read and store the height of line widgets associated with the
    // given line.
    function updateWidgetHeight(line) {
        if (line.widgets) {
            for (var i = 0; i < line.widgets.length; ++i) {
                var w = line.widgets[i],
                    parent = w.node.parentNode
                if (parent) {
                    w.height = parent.offsetHeight
                }
            }
        }
    }

    // Compute the lines that are visible in a given viewport (defaults
    // the the current scroll position). viewport may contain top,
    // height, and ensure (see op.scrollToPos) properties.
    function visibleLines(display, doc, viewport) {
        var top = viewport && viewport.top != null ? Math.max(0, viewport.top) : display.scroller.scrollTop
        top = Math.floor(top - paddingTop(display))
        var bottom = viewport && viewport.bottom != null ? viewport.bottom : top + display.wrapper.clientHeight

        var from = lineAtHeight(doc, top),
            to = lineAtHeight(doc, bottom)
        // Ensure is a {from: {line, ch}, to: {line, ch}} object, and
        // forces those lines into the viewport (if possible).
        if (viewport && viewport.ensure) {
            var ensureFrom = viewport.ensure.from.line,
                ensureTo = viewport.ensure.to.line
            if (ensureFrom < from) {
                from = ensureFrom
                to = lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight)
            } else if (Math.min(ensureTo, doc.lastLine()) >= to) {
                from = lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight)
                to = ensureTo
            }
        }
        return { from: from, to: Math.max(to, from + 1) }
    }

    // SCROLLING THINGS INTO VIEW

    // If an editor sits on the top or bottom of the window, partially
    // scrolled out of view, this ensures that the cursor is visible.
    function maybeScrollWindow(cm, rect) {
        if (signalDOMEvent(cm, 'scrollCursorIntoView')) {
            return
        }

        var display = cm.display,
            box = display.sizer.getBoundingClientRect(),
            doScroll = null
        if (rect.top + box.top < 0) {
            doScroll = true
        } else if (rect.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) {
            doScroll = false
        }
        if (doScroll != null && !phantom) {
            var scrollNode = elt(
                'div',
                '\u200b',
                null,
                'position: absolute;\n                         top: ' +
                    (rect.top - display.viewOffset - paddingTop(cm.display)) +
                    'px;\n                         height: ' +
                    (rect.bottom - rect.top + scrollGap(cm) + display.barHeight) +
                    'px;\n                         left: ' +
                    rect.left +
                    'px; width: ' +
                    Math.max(2, rect.right - rect.left) +
                    'px;'
            )
            cm.display.lineSpace.appendChild(scrollNode)
            scrollNode.scrollIntoView(doScroll)
            cm.display.lineSpace.removeChild(scrollNode)
        }
    }

    // Scroll a given position into view (immediately), verifying that
    // it actually became visible (as line heights are accurately
    // measured, the position of something may 'drift' during drawing).
    function scrollPosIntoView(cm, pos, end, margin) {
        if (margin == null) {
            margin = 0
        }
        var rect
        if (!cm.options.lineWrapping && pos == end) {
            // Set pos and end to the cursor positions around the character pos sticks to
            // If pos.sticky == "before", that is around pos.ch - 1, otherwise around pos.ch
            // If pos == Pos(_, 0, "before"), pos and end are unchanged
            end = pos.sticky == 'before' ? Pos(pos.line, pos.ch + 1, 'before') : pos
            pos = pos.ch ? Pos(pos.line, pos.sticky == 'before' ? pos.ch - 1 : pos.ch, 'after') : pos
        }
        for (var limit = 0; limit < 5; limit++) {
            var changed = false
            var coords = cursorCoords(cm, pos)
            var endCoords = !end || end == pos ? coords : cursorCoords(cm, end)
            rect = {
                left: Math.min(coords.left, endCoords.left),
                top: Math.min(coords.top, endCoords.top) - margin,
                right: Math.max(coords.left, endCoords.left),
                bottom: Math.max(coords.bottom, endCoords.bottom) + margin,
            }
            var scrollPos = calculateScrollPos(cm, rect)
            var startTop = cm.doc.scrollTop,
                startLeft = cm.doc.scrollLeft
            if (scrollPos.scrollTop != null) {
                updateScrollTop(cm, scrollPos.scrollTop)
                if (Math.abs(cm.doc.scrollTop - startTop) > 1) {
                    changed = true
                }
            }
            if (scrollPos.scrollLeft != null) {
                setScrollLeft(cm, scrollPos.scrollLeft)
                if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) {
                    changed = true
                }
            }
            if (!changed) {
                break
            }
        }
        return rect
    }

    // Scroll a given set of coordinates into view (immediately).
    function scrollIntoView(cm, rect) {
        var scrollPos = calculateScrollPos(cm, rect)
        if (scrollPos.scrollTop != null) {
            updateScrollTop(cm, scrollPos.scrollTop)
        }
        if (scrollPos.scrollLeft != null) {
            setScrollLeft(cm, scrollPos.scrollLeft)
        }
    }

    // Calculate a new scroll position needed to scroll the given
    // rectangle into view. Returns an object with scrollTop and
    // scrollLeft properties. When these are undefined, the
    // vertical/horizontal position does not need to be adjusted.
    function calculateScrollPos(cm, rect) {
        var display = cm.display,
            snapMargin = textHeight(cm.display)
        if (rect.top < 0) {
            rect.top = 0
        }
        var screentop = cm.curOp && cm.curOp.scrollTop != null ? cm.curOp.scrollTop : display.scroller.scrollTop
        var screen = displayHeight(cm),
            result = {}
        if (rect.bottom - rect.top > screen) {
            rect.bottom = rect.top + screen
        }
        var docBottom = cm.doc.height + paddingVert(display)
        var atTop = rect.top < snapMargin,
            atBottom = rect.bottom > docBottom - snapMargin
        if (rect.top < screentop) {
            result.scrollTop = atTop ? 0 : rect.top
        } else if (rect.bottom > screentop + screen) {
            var newTop = Math.min(rect.top, (atBottom ? docBottom : rect.bottom) - screen)
            if (newTop != screentop) {
                result.scrollTop = newTop
            }
        }

        var gutterSpace = cm.options.fixedGutter ? 0 : display.gutters.offsetWidth
        var screenleft = cm.curOp && cm.curOp.scrollLeft != null ? cm.curOp.scrollLeft : display.scroller.scrollLeft - gutterSpace
        var screenw = displayWidth(cm) - display.gutters.offsetWidth
        var tooWide = rect.right - rect.left > screenw
        if (tooWide) {
            rect.right = rect.left + screenw
        }
        if (rect.left < 10) {
            result.scrollLeft = 0
        } else if (rect.left < screenleft) {
            result.scrollLeft = Math.max(0, rect.left + gutterSpace - (tooWide ? 0 : 10))
        } else if (rect.right > screenw + screenleft - 3) {
            result.scrollLeft = rect.right + (tooWide ? 0 : 10) - screenw
        }
        return result
    }

    // Store a relative adjustment to the scroll position in the current
    // operation (to be applied when the operation finishes).
    function addToScrollTop(cm, top) {
        if (top == null) {
            return
        }
        resolveScrollToPos(cm)
        cm.curOp.scrollTop = (cm.curOp.scrollTop == null ? cm.doc.scrollTop : cm.curOp.scrollTop) + top
    }

    // Make sure that at the end of the operation the current cursor is
    // shown.
    function ensureCursorVisible(cm) {
        resolveScrollToPos(cm)
        var cur = cm.getCursor()
        cm.curOp.scrollToPos = { from: cur, to: cur, margin: cm.options.cursorScrollMargin }
    }

    function scrollToCoords(cm, x, y) {
        if (x != null || y != null) {
            resolveScrollToPos(cm)
        }
        if (x != null) {
            cm.curOp.scrollLeft = x
        }
        if (y != null) {
            cm.curOp.scrollTop = y
        }
    }

    function scrollToRange(cm, range) {
        resolveScrollToPos(cm)
        cm.curOp.scrollToPos = range
    }

    // When an operation has its scrollToPos property set, and another
    // scroll action is applied before the end of the operation, this
    // 'simulates' scrolling that position into view in a cheap way, so
    // that the effect of intermediate scroll commands is not ignored.
    function resolveScrollToPos(cm) {
        var range = cm.curOp.scrollToPos
        if (range) {
            cm.curOp.scrollToPos = null
            var from = estimateCoords(cm, range.from),
                to = estimateCoords(cm, range.to)
            scrollToCoordsRange(cm, from, to, range.margin)
        }
    }

    function scrollToCoordsRange(cm, from, to, margin) {
        var sPos = calculateScrollPos(cm, {
            left: Math.min(from.left, to.left),
            top: Math.min(from.top, to.top) - margin,
            right: Math.max(from.right, to.right),
            bottom: Math.max(from.bottom, to.bottom) + margin,
        })
        scrollToCoords(cm, sPos.scrollLeft, sPos.scrollTop)
    }

    // Sync the scrollable area and scrollbars, ensure the viewport
    // covers the visible area.
    function updateScrollTop(cm, val) {
        if (Math.abs(cm.doc.scrollTop - val) < 2) {
            return
        }
        if (!gecko) {
            updateDisplaySimple(cm, { top: val })
        }
        setScrollTop(cm, val, true)
        if (gecko) {
            updateDisplaySimple(cm)
        }
        startWorker(cm, 100)
    }

    function setScrollTop(cm, val, forceScroll) {
        val = Math.max(0, Math.min(cm.display.scroller.scrollHeight - cm.display.scroller.clientHeight, val))
        if (cm.display.scroller.scrollTop == val && !forceScroll) {
            return
        }
        cm.doc.scrollTop = val
        cm.display.scrollbars.setScrollTop(val)
        if (cm.display.scroller.scrollTop != val) {
            cm.display.scroller.scrollTop = val
        }
    }

    // Sync scroller and scrollbar, ensure the gutter elements are
    // aligned.
    function setScrollLeft(cm, val, isScroller, forceScroll) {
        val = Math.max(0, Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth))
        if ((isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) && !forceScroll) {
            return
        }
        cm.doc.scrollLeft = val
        alignHorizontally(cm)
        if (cm.display.scroller.scrollLeft != val) {
            cm.display.scroller.scrollLeft = val
        }
        cm.display.scrollbars.setScrollLeft(val)
    }

    // SCROLLBARS

    // Prepare DOM reads needed to update the scrollbars. Done in one
    // shot to minimize update/measure roundtrips.
    function measureForScrollbars(cm) {
        var d = cm.display,
            gutterW = d.gutters.offsetWidth
        var docH = Math.round(cm.doc.height + paddingVert(cm.display))
        return {
            clientHeight: d.scroller.clientHeight,
            viewHeight: d.wrapper.clientHeight,
            scrollWidth: d.scroller.scrollWidth,
            clientWidth: d.scroller.clientWidth,
            viewWidth: d.wrapper.clientWidth,
            barLeft: cm.options.fixedGutter ? gutterW : 0,
            docHeight: docH,
            scrollHeight: docH + scrollGap(cm) + d.barHeight,
            nativeBarWidth: d.nativeBarWidth,
            gutterWidth: gutterW,
        }
    }

    var NativeScrollbars = function (place, scroll, cm) {
        this.cm = cm
        var vert = (this.vert = elt('div', [elt('div', null, null, 'min-width: 1px')], 'CodeMirror-vscrollbar'))
        var horiz = (this.horiz = elt('div', [elt('div', null, null, 'height: 100%; min-height: 1px')], 'CodeMirror-hscrollbar'))
        vert.tabIndex = horiz.tabIndex = -1
        place(vert)
        place(horiz)

        on(vert, 'scroll', function () {
            if (vert.clientHeight) {
                scroll(vert.scrollTop, 'vertical')
            }
        })
        on(horiz, 'scroll', function () {
            if (horiz.clientWidth) {
                scroll(horiz.scrollLeft, 'horizontal')
            }
        })

        this.checkedZeroWidth = false
        // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
        if (ie && ie_version < 8) {
            this.horiz.style.minHeight = this.vert.style.minWidth = '18px'
        }
    }

    NativeScrollbars.prototype.update = function (measure) {
        var needsH = measure.scrollWidth > measure.clientWidth + 1
        var needsV = measure.scrollHeight > measure.clientHeight + 1
        var sWidth = measure.nativeBarWidth

        if (needsV) {
            this.vert.style.display = 'block'
            this.vert.style.bottom = needsH ? sWidth + 'px' : '0'
            var totalHeight = measure.viewHeight - (needsH ? sWidth : 0)
            // A bug in IE8 can cause this value to be negative, so guard it.
            this.vert.firstChild.style.height = Math.max(0, measure.scrollHeight - measure.clientHeight + totalHeight) + 'px'
        } else {
            this.vert.scrollTop = 0
            this.vert.style.display = ''
            this.vert.firstChild.style.height = '0'
        }

        if (needsH) {
            this.horiz.style.display = 'block'
            this.horiz.style.right = needsV ? sWidth + 'px' : '0'
            this.horiz.style.left = measure.barLeft + 'px'
            var totalWidth = measure.viewWidth - measure.barLeft - (needsV ? sWidth : 0)
            this.horiz.firstChild.style.width = Math.max(0, measure.scrollWidth - measure.clientWidth + totalWidth) + 'px'
        } else {
            this.horiz.style.display = ''
            this.horiz.firstChild.style.width = '0'
        }

        if (!this.checkedZeroWidth && measure.clientHeight > 0) {
            if (sWidth == 0) {
                this.zeroWidthHack()
            }
            this.checkedZeroWidth = true
        }

        return { right: needsV ? sWidth : 0, bottom: needsH ? sWidth : 0 }
    }

    NativeScrollbars.prototype.setScrollLeft = function (pos) {
        if (this.horiz.scrollLeft != pos) {
            this.horiz.scrollLeft = pos
        }
        if (this.disableHoriz) {
            this.enableZeroWidthBar(this.horiz, this.disableHoriz, 'horiz')
        }
    }

    NativeScrollbars.prototype.setScrollTop = function (pos) {
        if (this.vert.scrollTop != pos) {
            this.vert.scrollTop = pos
        }
        if (this.disableVert) {
            this.enableZeroWidthBar(this.vert, this.disableVert, 'vert')
        }
    }

    NativeScrollbars.prototype.zeroWidthHack = function () {
        var w = mac && !mac_geMountainLion ? '12px' : '18px'
        this.horiz.style.height = this.vert.style.width = w
        this.horiz.style.pointerEvents = this.vert.style.pointerEvents = 'none'
        this.disableHoriz = new Delayed()
        this.disableVert = new Delayed()
    }

    NativeScrollbars.prototype.enableZeroWidthBar = function (bar, delay, type) {
        bar.style.pointerEvents = 'auto'
        function maybeDisable() {
            // To find out whether the scrollbar is still visible, we
            // check whether the element under the pixel in the bottom
            // right corner of the scrollbar box is the scrollbar box
            // itself (when the bar is still visible) or its filler child
            // (when the bar is hidden). If it is still visible, we keep
            // it enabled, if it's hidden, we disable pointer events.
            var box = bar.getBoundingClientRect()
            var elt = type == 'vert' ? document.elementFromPoint(box.right - 1, (box.top + box.bottom) / 2) : document.elementFromPoint((box.right + box.left) / 2, box.bottom - 1)
            if (elt != bar) {
                bar.style.pointerEvents = 'none'
            } else {
                delay.set(1000, maybeDisable)
            }
        }
        delay.set(1000, maybeDisable)
    }

    NativeScrollbars.prototype.clear = function () {
        var parent = this.horiz.parentNode
        parent.removeChild(this.horiz)
        parent.removeChild(this.vert)
    }

    var NullScrollbars = function () {}

    NullScrollbars.prototype.update = function () {
        return { bottom: 0, right: 0 }
    }
    NullScrollbars.prototype.setScrollLeft = function () {}
    NullScrollbars.prototype.setScrollTop = function () {}
    NullScrollbars.prototype.clear = function () {}

    function updateScrollbars(cm, measure) {
        if (!measure) {
            measure = measureForScrollbars(cm)
        }
        var startWidth = cm.display.barWidth,
            startHeight = cm.display.barHeight
        updateScrollbarsInner(cm, measure)
        for (var i = 0; (i < 4 && startWidth != cm.display.barWidth) || startHeight != cm.display.barHeight; i++) {
            if (startWidth != cm.display.barWidth && cm.options.lineWrapping) {
                updateHeightsInViewport(cm)
            }
            updateScrollbarsInner(cm, measureForScrollbars(cm))
            startWidth = cm.display.barWidth
            startHeight = cm.display.barHeight
        }
    }

    // Re-synchronize the fake scrollbars with the actual size of the
    // content.
    function updateScrollbarsInner(cm, measure) {
        var d = cm.display
        var sizes = d.scrollbars.update(measure)

        d.sizer.style.paddingRight = (d.barWidth = sizes.right) + 'px'
        d.sizer.style.paddingBottom = (d.barHeight = sizes.bottom) + 'px'
        d.heightForcer.style.borderBottom = sizes.bottom + 'px solid transparent'

        if (sizes.right && sizes.bottom) {
            d.scrollbarFiller.style.display = 'block'
            d.scrollbarFiller.style.height = sizes.bottom + 'px'
            d.scrollbarFiller.style.width = sizes.right + 'px'
        } else {
            d.scrollbarFiller.style.display = ''
        }
        if (sizes.bottom && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
            d.gutterFiller.style.display = 'block'
            d.gutterFiller.style.height = sizes.bottom + 'px'
            d.gutterFiller.style.width = measure.gutterWidth + 'px'
        } else {
            d.gutterFiller.style.display = ''
        }
    }

    var scrollbarModel = { native: NativeScrollbars, null: NullScrollbars }

    function initScrollbars(cm) {
        if (cm.display.scrollbars) {
            cm.display.scrollbars.clear()
            if (cm.display.scrollbars.addClass) {
                rmClass(cm.display.wrapper, cm.display.scrollbars.addClass)
            }
        }

        cm.display.scrollbars = new scrollbarModel[cm.options.scrollbarStyle](
            function (node) {
                cm.display.wrapper.insertBefore(node, cm.display.scrollbarFiller)
                // Prevent clicks in the scrollbars from killing focus
                on(node, 'mousedown', function () {
                    if (cm.state.focused) {
                        setTimeout(function () {
                            return cm.display.input.focus()
                        }, 0)
                    }
                })
                node.setAttribute('cm-not-content', 'true')
            },
            function (pos, axis) {
                if (axis == 'horizontal') {
                    setScrollLeft(cm, pos)
                } else {
                    updateScrollTop(cm, pos)
                }
            },
            cm
        )
        if (cm.display.scrollbars.addClass) {
            addClass(cm.display.wrapper, cm.display.scrollbars.addClass)
        }
    }

    // Operations are used to wrap a series of changes to the editor
    // state in such a way that each change won't have to update the
    // cursor and display (which would be awkward, slow, and
    // error-prone). Instead, display updates are batched and then all
    // combined and executed at once.

    var nextOpId = 0
    // Start a new operation.
    function startOperation(cm) {
        cm.curOp = {
            cm: cm,
            viewChanged: false, // Flag that indicates that lines might need to be redrawn
            startHeight: cm.doc.height, // Used to detect need to update scrollbar
            forceUpdate: false, // Used to force a redraw
            updateInput: 0, // Whether to reset the input textarea
            typing: false, // Whether this reset should be careful to leave existing text (for compositing)
            changeObjs: null, // Accumulated changes, for firing change events
            cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on
            cursorActivityCalled: 0, // Tracks which cursorActivity handlers have been called already
            selectionChanged: false, // Whether the selection needs to be redrawn
            updateMaxLine: false, // Set when the widest line needs to be determined anew
            scrollLeft: null,
            scrollTop: null, // Intermediate scroll position, not pushed to DOM yet
            scrollToPos: null, // Used to scroll to a specific position
            focus: false,
            id: ++nextOpId, // Unique ID
            markArrays: null, // Used by addMarkedSpan
        }
        pushOperation(cm.curOp)
    }

    // Finish an operation, updating the display and signalling delayed events
    function endOperation(cm) {
        var op = cm.curOp
        if (op) {
            finishOperation(op, function (group) {
                for (var i = 0; i < group.ops.length; i++) {
                    group.ops[i].cm.curOp = null
                }
                endOperations(group)
            })
        }
    }

    // The DOM updates done when an operation finishes are batched so
    // that the minimum number of relayouts are required.
    function endOperations(group) {
        var ops = group.ops
        for (
            var i = 0;
            i < ops.length;
            i++ // Read DOM
        ) {
            endOperation_R1(ops[i])
        }
        for (
            var i$1 = 0;
            i$1 < ops.length;
            i$1++ // Write DOM (maybe)
        ) {
            endOperation_W1(ops[i$1])
        }
        for (
            var i$2 = 0;
            i$2 < ops.length;
            i$2++ // Read DOM
        ) {
            endOperation_R2(ops[i$2])
        }
        for (
            var i$3 = 0;
            i$3 < ops.length;
            i$3++ // Write DOM (maybe)
        ) {
            endOperation_W2(ops[i$3])
        }
        for (
            var i$4 = 0;
            i$4 < ops.length;
            i$4++ // Read DOM
        ) {
            endOperation_finish(ops[i$4])
        }
    }

    function endOperation_R1(op) {
        var cm = op.cm,
            display = cm.display
        maybeClipScrollbars(cm)
        if (op.updateMaxLine) {
            findMaxLine(cm)
        }

        op.mustUpdate =
            op.viewChanged ||
            op.forceUpdate ||
            op.scrollTop != null ||
            (op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom || op.scrollToPos.to.line >= display.viewTo)) ||
            (display.maxLineChanged && cm.options.lineWrapping)
        op.update = op.mustUpdate && new DisplayUpdate(cm, op.mustUpdate && { top: op.scrollTop, ensure: op.scrollToPos }, op.forceUpdate)
    }

    function endOperation_W1(op) {
        op.updatedDisplay = op.mustUpdate && updateDisplayIfNeeded(op.cm, op.update)
    }

    function endOperation_R2(op) {
        var cm = op.cm,
            display = cm.display
        if (op.updatedDisplay) {
            updateHeightsInViewport(cm)
        }

        op.barMeasure = measureForScrollbars(cm)

        // If the max line changed since it was last measured, measure it,
        // and ensure the document's width matches it.
        // updateDisplay_W2 will use these properties to do the actual resizing
        if (display.maxLineChanged && !cm.options.lineWrapping) {
            op.adjustWidthTo = measureChar(cm, display.maxLine, display.maxLine.text.length).left + 3
            cm.display.sizerWidth = op.adjustWidthTo
            op.barMeasure.scrollWidth = Math.max(display.scroller.clientWidth, display.sizer.offsetLeft + op.adjustWidthTo + scrollGap(cm) + cm.display.barWidth)
            op.maxScrollLeft = Math.max(0, display.sizer.offsetLeft + op.adjustWidthTo - displayWidth(cm))
        }

        if (op.updatedDisplay || op.selectionChanged) {
            op.preparedSelection = display.input.prepareSelection()
        }
    }

    function endOperation_W2(op) {
        var cm = op.cm

        if (op.adjustWidthTo != null) {
            cm.display.sizer.style.minWidth = op.adjustWidthTo + 'px'
            if (op.maxScrollLeft < cm.doc.scrollLeft) {
                setScrollLeft(cm, Math.min(cm.display.scroller.scrollLeft, op.maxScrollLeft), true)
            }
            cm.display.maxLineChanged = false
        }

        var takeFocus = op.focus && op.focus == activeElt()
        if (op.preparedSelection) {
            cm.display.input.showSelection(op.preparedSelection, takeFocus)
        }
        if (op.updatedDisplay || op.startHeight != cm.doc.height) {
            updateScrollbars(cm, op.barMeasure)
        }
        if (op.updatedDisplay) {
            setDocumentHeight(cm, op.barMeasure)
        }

        if (op.selectionChanged) {
            restartBlink(cm)
        }

        if (cm.state.focused && op.updateInput) {
            cm.display.input.reset(op.typing)
        }
        if (takeFocus) {
            ensureFocus(op.cm)
        }
    }

    function endOperation_finish(op) {
        var cm = op.cm,
            display = cm.display,
            doc = cm.doc

        if (op.updatedDisplay) {
            postUpdateDisplay(cm, op.update)
        }

        // Abort mouse wheel delta measurement, when scrolling explicitly
        if (display.wheelStartX != null && (op.scrollTop != null || op.scrollLeft != null || op.scrollToPos)) {
            display.wheelStartX = display.wheelStartY = null
        }

        // Propagate the scroll position to the actual DOM scroller
        if (op.scrollTop != null) {
            setScrollTop(cm, op.scrollTop, op.forceScroll)
        }

        if (op.scrollLeft != null) {
            setScrollLeft(cm, op.scrollLeft, true, true)
        }
        // If we need to scroll a specific position into view, do so.
        if (op.scrollToPos) {
            var rect = scrollPosIntoView(cm, clipPos(doc, op.scrollToPos.from), clipPos(doc, op.scrollToPos.to), op.scrollToPos.margin)
            maybeScrollWindow(cm, rect)
        }

        // Fire events for markers that are hidden/unidden by editing or
        // undoing
        var hidden = op.maybeHiddenMarkers,
            unhidden = op.maybeUnhiddenMarkers
        if (hidden) {
            for (var i = 0; i < hidden.length; ++i) {
                if (!hidden[i].lines.length) {
                    signal(hidden[i], 'hide')
                }
            }
        }
        if (unhidden) {
            for (var i$1 = 0; i$1 < unhidden.length; ++i$1) {
                if (unhidden[i$1].lines.length) {
                    signal(unhidden[i$1], 'unhide')
                }
            }
        }

        if (display.wrapper.offsetHeight) {
            doc.scrollTop = cm.display.scroller.scrollTop
        }

        // Fire change events, and delayed event handlers
        if (op.changeObjs) {
            signal(cm, 'changes', cm, op.changeObjs)
        }
        if (op.update) {
            op.update.finish()
        }
    }

    // Run the given function in an operation
    function runInOp(cm, f) {
        if (cm.curOp) {
            return f()
        }
        startOperation(cm)
        try {
            return f()
        } finally {
            endOperation(cm)
        }
    }
    // Wraps a function in an operation. Returns the wrapped function.
    function operation(cm, f) {
        return function () {
            if (cm.curOp) {
                return f.apply(cm, arguments)
            }
            startOperation(cm)
            try {
                return f.apply(cm, arguments)
            } finally {
                endOperation(cm)
            }
        }
    }
    // Used to add methods to editor and doc instances, wrapping them in
    // operations.
    function methodOp(f) {
        return function () {
            if (this.curOp) {
                return f.apply(this, arguments)
            }
            startOperation(this)
            try {
                return f.apply(this, arguments)
            } finally {
                endOperation(this)
            }
        }
    }
    function docMethodOp(f) {
        return function () {
            var cm = this.cm
            if (!cm || cm.curOp) {
                return f.apply(this, arguments)
            }
            startOperation(cm)
            try {
                return f.apply(this, arguments)
            } finally {
                endOperation(cm)
            }
        }
    }

    // HIGHLIGHT WORKER

    function startWorker(cm, time) {
        if (cm.doc.highlightFrontier < cm.display.viewTo) {
            cm.state.highlight.set(time, bind(highlightWorker, cm))
        }
    }

    function highlightWorker(cm) {
        var doc = cm.doc
        if (doc.highlightFrontier >= cm.display.viewTo) {
            return
        }
        var end = +new Date() + cm.options.workTime
        var context = getContextBefore(cm, doc.highlightFrontier)
        var changedLines = []

        doc.iter(context.line, Math.min(doc.first + doc.size, cm.display.viewTo + 500), function (line) {
            if (context.line >= cm.display.viewFrom) {
                // Visible
                var oldStyles = line.styles
                var resetState = line.text.length > cm.options.maxHighlightLength ? copyState(doc.mode, context.state) : null
                var highlighted = highlightLine(cm, line, context, true)
                if (resetState) {
                    context.state = resetState
                }
                line.styles = highlighted.styles
                var oldCls = line.styleClasses,
                    newCls = highlighted.classes
                if (newCls) {
                    line.styleClasses = newCls
                } else if (oldCls) {
                    line.styleClasses = null
                }
                var ischange =
                    !oldStyles || oldStyles.length != line.styles.length || (oldCls != newCls && (!oldCls || !newCls || oldCls.bgClass != newCls.bgClass || oldCls.textClass != newCls.textClass))
                for (var i = 0; !ischange && i < oldStyles.length; ++i) {
                    ischange = oldStyles[i] != line.styles[i]
                }
                if (ischange) {
                    changedLines.push(context.line)
                }
                line.stateAfter = context.save()
                context.nextLine()
            } else {
                if (line.text.length <= cm.options.maxHighlightLength) {
                    processLine(cm, line.text, context)
                }
                line.stateAfter = context.line % 5 == 0 ? context.save() : null
                context.nextLine()
            }
            if (+new Date() > end) {
                startWorker(cm, cm.options.workDelay)
                return true
            }
        })
        doc.highlightFrontier = context.line
        doc.modeFrontier = Math.max(doc.modeFrontier, context.line)
        if (changedLines.length) {
            runInOp(cm, function () {
                for (var i = 0; i < changedLines.length; i++) {
                    regLineChange(cm, changedLines[i], 'text')
                }
            })
        }
    }

    // DISPLAY DRAWING

    var DisplayUpdate = function (cm, viewport, force) {
        var display = cm.display

        this.viewport = viewport
        // Store some values that we'll need later (but don't want to force a relayout for)
        this.visible = visibleLines(display, cm.doc, viewport)
        this.editorIsHidden = !display.wrapper.offsetWidth
        this.wrapperHeight = display.wrapper.clientHeight
        this.wrapperWidth = display.wrapper.clientWidth
        this.oldDisplayWidth = displayWidth(cm)
        this.force = force
        this.dims = getDimensions(cm)
        this.events = []
    }

    DisplayUpdate.prototype.signal = function (emitter, type) {
        if (hasHandler(emitter, type)) {
            this.events.push(arguments)
        }
    }
    DisplayUpdate.prototype.finish = function () {
        for (var i = 0; i < this.events.length; i++) {
            signal.apply(null, this.events[i])
        }
    }

    function maybeClipScrollbars(cm) {
        var display = cm.display
        if (!display.scrollbarsClipped && display.scroller.offsetWidth) {
            display.nativeBarWidth = display.scroller.offsetWidth - display.scroller.clientWidth
            display.heightForcer.style.height = scrollGap(cm) + 'px'
            display.sizer.style.marginBottom = -display.nativeBarWidth + 'px'
            display.sizer.style.borderRightWidth = scrollGap(cm) + 'px'
            display.scrollbarsClipped = true
        }
    }

    function selectionSnapshot(cm) {
        if (cm.hasFocus()) {
            return null
        }
        var active = activeElt()
        if (!active || !contains(cm.display.lineDiv, active)) {
            return null
        }
        var result = { activeElt: active }
        if (window.getSelection) {
            var sel = window.getSelection()
            if (sel.anchorNode && sel.extend && contains(cm.display.lineDiv, sel.anchorNode)) {
                result.anchorNode = sel.anchorNode
                result.anchorOffset = sel.anchorOffset
                result.focusNode = sel.focusNode
                result.focusOffset = sel.focusOffset
            }
        }
        return result
    }

    function restoreSelection(snapshot) {
        if (!snapshot || !snapshot.activeElt || snapshot.activeElt == activeElt()) {
            return
        }
        snapshot.activeElt.focus()
        if (!/^(INPUT|TEXTAREA)$/.test(snapshot.activeElt.nodeName) && snapshot.anchorNode && contains(document.body, snapshot.anchorNode) && contains(document.body, snapshot.focusNode)) {
            var sel = window.getSelection(),
                range = document.createRange()
            range.setEnd(snapshot.anchorNode, snapshot.anchorOffset)
            range.collapse(false)
            sel.removeAllRanges()
            sel.addRange(range)
            sel.extend(snapshot.focusNode, snapshot.focusOffset)
        }
    }

    // Does the actual updating of the line display. Bails out
    // (returning false) when there is nothing to be done and forced is
    // false.
    function updateDisplayIfNeeded(cm, update) {
        var display = cm.display,
            doc = cm.doc

        if (update.editorIsHidden) {
            resetView(cm)
            return false
        }

        // Bail out if the visible area is already rendered and nothing changed.
        if (
            !update.force &&
            update.visible.from >= display.viewFrom &&
            update.visible.to <= display.viewTo &&
            (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo) &&
            display.renderedView == display.view &&
            countDirtyView(cm) == 0
        ) {
            return false
        }

        if (maybeUpdateLineNumberWidth(cm)) {
            resetView(cm)
            update.dims = getDimensions(cm)
        }

        // Compute a suitable new viewport (from & to)
        var end = doc.first + doc.size
        var from = Math.max(update.visible.from - cm.options.viewportMargin, doc.first)
        var to = Math.min(end, update.visible.to + cm.options.viewportMargin)
        if (display.viewFrom < from && from - display.viewFrom < 20) {
            from = Math.max(doc.first, display.viewFrom)
        }
        if (display.viewTo > to && display.viewTo - to < 20) {
            to = Math.min(end, display.viewTo)
        }
        if (sawCollapsedSpans) {
            from = visualLineNo(cm.doc, from)
            to = visualLineEndNo(cm.doc, to)
        }

        var different = from != display.viewFrom || to != display.viewTo || display.lastWrapHeight != update.wrapperHeight || display.lastWrapWidth != update.wrapperWidth
        adjustView(cm, from, to)

        display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom))
        // Position the mover div to align with the current scroll position
        cm.display.mover.style.top = display.viewOffset + 'px'

        var toUpdate = countDirtyView(cm)
        if (!different && toUpdate == 0 && !update.force && display.renderedView == display.view && (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo)) {
            return false
        }

        // For big changes, we hide the enclosing element during the
        // update, since that speeds up the operations on most browsers.
        var selSnapshot = selectionSnapshot(cm)
        if (toUpdate > 4) {
            display.lineDiv.style.display = 'none'
        }
        patchDisplay(cm, display.updateLineNumbers, update.dims)
        if (toUpdate > 4) {
            display.lineDiv.style.display = ''
        }
        display.renderedView = display.view
        // There might have been a widget with a focused element that got
        // hidden or updated, if so re-focus it.
        restoreSelection(selSnapshot)

        // Prevent selection and cursors from interfering with the scroll
        // width and height.
        removeChildren(display.cursorDiv)
        removeChildren(display.selectionDiv)
        display.gutters.style.height = display.sizer.style.minHeight = 0

        if (different) {
            display.lastWrapHeight = update.wrapperHeight
            display.lastWrapWidth = update.wrapperWidth
            startWorker(cm, 400)
        }

        display.updateLineNumbers = null

        return true
    }

    function postUpdateDisplay(cm, update) {
        var viewport = update.viewport

        for (var first = true; ; first = false) {
            if (!first || !cm.options.lineWrapping || update.oldDisplayWidth == displayWidth(cm)) {
                // Clip forced viewport to actual scrollable area.
                if (viewport && viewport.top != null) {
                    viewport = { top: Math.min(cm.doc.height + paddingVert(cm.display) - displayHeight(cm), viewport.top) }
                }
                // Updated line heights might result in the drawn area not
                // actually covering the viewport. Keep looping until it does.
                update.visible = visibleLines(cm.display, cm.doc, viewport)
                if (update.visible.from >= cm.display.viewFrom && update.visible.to <= cm.display.viewTo) {
                    break
                }
            } else if (first) {
                update.visible = visibleLines(cm.display, cm.doc, viewport)
            }
            if (!updateDisplayIfNeeded(cm, update)) {
                break
            }
            updateHeightsInViewport(cm)
            var barMeasure = measureForScrollbars(cm)
            updateSelection(cm)
            updateScrollbars(cm, barMeasure)
            setDocumentHeight(cm, barMeasure)
            update.force = false
        }

        update.signal(cm, 'update', cm)
        if (cm.display.viewFrom != cm.display.reportedViewFrom || cm.display.viewTo != cm.display.reportedViewTo) {
            update.signal(cm, 'viewportChange', cm, cm.display.viewFrom, cm.display.viewTo)
            cm.display.reportedViewFrom = cm.display.viewFrom
            cm.display.reportedViewTo = cm.display.viewTo
        }
    }

    function updateDisplaySimple(cm, viewport) {
        var update = new DisplayUpdate(cm, viewport)
        if (updateDisplayIfNeeded(cm, update)) {
            updateHeightsInViewport(cm)
            postUpdateDisplay(cm, update)
            var barMeasure = measureForScrollbars(cm)
            updateSelection(cm)
            updateScrollbars(cm, barMeasure)
            setDocumentHeight(cm, barMeasure)
            update.finish()
        }
    }

    // Sync the actual display DOM structure with display.view, removing
    // nodes for lines that are no longer in view, and creating the ones
    // that are not there yet, and updating the ones that are out of
    // date.
    function patchDisplay(cm, updateNumbersFrom, dims) {
        var display = cm.display,
            lineNumbers = cm.options.lineNumbers
        var container = display.lineDiv,
            cur = container.firstChild

        function rm(node) {
            var next = node.nextSibling
            // Works around a throw-scroll bug in OS X Webkit
            if (webkit && mac && cm.display.currentWheelTarget == node) {
                node.style.display = 'none'
            } else {
                node.parentNode.removeChild(node)
            }
            return next
        }

        var view = display.view,
            lineN = display.viewFrom
        // Loop over the elements in the view, syncing cur (the DOM nodes
        // in display.lineDiv) with the view as we go.
        for (var i = 0; i < view.length; i++) {
            var lineView = view[i]
            if (lineView.hidden);
            else if (!lineView.node || lineView.node.parentNode != container) {
                // Not drawn yet
                var node = buildLineElement(cm, lineView, lineN, dims)
                container.insertBefore(node, cur)
            } else {
                // Already drawn
                while (cur != lineView.node) {
                    cur = rm(cur)
                }
                var updateNumber = lineNumbers && updateNumbersFrom != null && updateNumbersFrom <= lineN && lineView.lineNumber
                if (lineView.changes) {
                    if (indexOf(lineView.changes, 'gutter') > -1) {
                        updateNumber = false
                    }
                    updateLineForChanges(cm, lineView, lineN, dims)
                }
                if (updateNumber) {
                    removeChildren(lineView.lineNumber)
                    lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)))
                }
                cur = lineView.node.nextSibling
            }
            lineN += lineView.size
        }
        while (cur) {
            cur = rm(cur)
        }
    }

    function updateGutterSpace(display) {
        var width = display.gutters.offsetWidth
        display.sizer.style.marginLeft = width + 'px'
        // Send an event to consumers responding to changes in gutter width.
        signalLater(display, 'gutterChanged', display)
    }

    function setDocumentHeight(cm, measure) {
        cm.display.sizer.style.minHeight = measure.docHeight + 'px'
        cm.display.heightForcer.style.top = measure.docHeight + 'px'
        cm.display.gutters.style.height = measure.docHeight + cm.display.barHeight + scrollGap(cm) + 'px'
    }

    // Re-align line numbers and gutter marks to compensate for
    // horizontal scrolling.
    function alignHorizontally(cm) {
        var display = cm.display,
            view = display.view
        if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) {
            return
        }
        var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft
        var gutterW = display.gutters.offsetWidth,
            left = comp + 'px'
        for (var i = 0; i < view.length; i++) {
            if (!view[i].hidden) {
                if (cm.options.fixedGutter) {
                    if (view[i].gutter) {
                        view[i].gutter.style.left = left
                    }
                    if (view[i].gutterBackground) {
                        view[i].gutterBackground.style.left = left
                    }
                }
                var align = view[i].alignable
                if (align) {
                    for (var j = 0; j < align.length; j++) {
                        align[j].style.left = left
                    }
                }
            }
        }
        if (cm.options.fixedGutter) {
            display.gutters.style.left = comp + gutterW + 'px'
        }
    }

    // Used to ensure that the line number gutter is still the right
    // size for the current document size. Returns true when an update
    // is needed.
    function maybeUpdateLineNumberWidth(cm) {
        if (!cm.options.lineNumbers) {
            return false
        }
        var doc = cm.doc,
            last = lineNumberFor(cm.options, doc.first + doc.size - 1),
            display = cm.display
        if (last.length != display.lineNumChars) {
            var test = display.measure.appendChild(elt('div', [elt('div', last)], 'CodeMirror-linenumber CodeMirror-gutter-elt'))
            var innerW = test.firstChild.offsetWidth,
                padding = test.offsetWidth - innerW
            display.lineGutter.style.width = ''
            display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding) + 1
            display.lineNumWidth = display.lineNumInnerWidth + padding
            display.lineNumChars = display.lineNumInnerWidth ? last.length : -1
            display.lineGutter.style.width = display.lineNumWidth + 'px'
            updateGutterSpace(cm.display)
            return true
        }
        return false
    }

    function getGutters(gutters, lineNumbers) {
        var result = [],
            sawLineNumbers = false
        for (var i = 0; i < gutters.length; i++) {
            var name = gutters[i],
                style = null
            if (typeof name != 'string') {
                style = name.style
                name = name.className
            }
            if (name == 'CodeMirror-linenumbers') {
                if (!lineNumbers) {
                    continue
                } else {
                    sawLineNumbers = true
                }
            }
            result.push({ className: name, style: style })
        }
        if (lineNumbers && !sawLineNumbers) {
            result.push({ className: 'CodeMirror-linenumbers', style: null })
        }
        return result
    }

    // Rebuild the gutter elements, ensure the margin to the left of the
    // code matches their width.
    function renderGutters(display) {
        var gutters = display.gutters,
            specs = display.gutterSpecs
        removeChildren(gutters)
        display.lineGutter = null
        for (var i = 0; i < specs.length; ++i) {
            var ref = specs[i]
            var className = ref.className
            var style = ref.style
            var gElt = gutters.appendChild(elt('div', null, 'CodeMirror-gutter ' + className))
            if (style) {
                gElt.style.cssText = style
            }
            if (className == 'CodeMirror-linenumbers') {
                display.lineGutter = gElt
                gElt.style.width = (display.lineNumWidth || 1) + 'px'
            }
        }
        gutters.style.display = specs.length ? '' : 'none'
        updateGutterSpace(display)
    }

    function updateGutters(cm) {
        renderGutters(cm.display)
        regChange(cm)
        alignHorizontally(cm)
    }

    // The display handles the DOM integration, both for input reading
    // and content drawing. It holds references to DOM nodes and
    // display-related state.

    function Display(place, doc, input, options) {
        var d = this
        this.input = input

        // Covers bottom-right square when both scrollbars are present.
        d.scrollbarFiller = elt('div', null, 'CodeMirror-scrollbar-filler')
        d.scrollbarFiller.setAttribute('cm-not-content', 'true')
        // Covers bottom of gutter when coverGutterNextToScrollbar is on
        // and h scrollbar is present.
        d.gutterFiller = elt('div', null, 'CodeMirror-gutter-filler')
        d.gutterFiller.setAttribute('cm-not-content', 'true')
        // Will contain the actual code, positioned to cover the viewport.
        d.lineDiv = eltP('div', null, 'CodeMirror-code')
        // Elements are added to these to represent selection and cursors.
        d.selectionDiv = elt('div', null, null, 'position: relative; z-index: 1')
        d.cursorDiv = elt('div', null, 'CodeMirror-cursors')
        // A visibility: hidden element used to find the size of things.
        d.measure = elt('div', null, 'CodeMirror-measure')
        // When lines outside of the viewport are measured, they are drawn in this.
        d.lineMeasure = elt('div', null, 'CodeMirror-measure')
        // Wraps everything that needs to exist inside the vertically-padded coordinate system
        d.lineSpace = eltP('div', [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv], null, 'position: relative; outline: none')
        var lines = eltP('div', [d.lineSpace], 'CodeMirror-lines')
        // Moved around its parent to cover visible view.
        d.mover = elt('div', [lines], null, 'position: relative')
        // Set to the height of the document, allowing scrolling.
        d.sizer = elt('div', [d.mover], 'CodeMirror-sizer')
        d.sizerWidth = null
        // Behavior of elts with overflow: auto and padding is
        // inconsistent across browsers. This is used to ensure the
        // scrollable area is big enough.
        d.heightForcer = elt('div', null, null, 'position: absolute; height: ' + scrollerGap + 'px; width: 1px;')
        // Will contain the gutters, if any.
        d.gutters = elt('div', null, 'CodeMirror-gutters')
        d.lineGutter = null
        // Actual scrollable element.
        d.scroller = elt('div', [d.sizer, d.heightForcer, d.gutters], 'CodeMirror-scroll')
        d.scroller.setAttribute('tabIndex', '-1')
        // The element in which the editor lives.
        d.wrapper = elt('div', [d.scrollbarFiller, d.gutterFiller, d.scroller], 'CodeMirror')

        // This attribute is respected by automatic translation systems such as Google Translate,
        // and may also be respected by tools used by human translators.
        d.wrapper.setAttribute('translate', 'no')

        // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
        if (ie && ie_version < 8) {
            d.gutters.style.zIndex = -1
            d.scroller.style.paddingRight = 0
        }
        if (!webkit && !(gecko && mobile)) {
            d.scroller.draggable = true
        }

        if (place) {
            if (place.appendChild) {
                place.appendChild(d.wrapper)
            } else {
                place(d.wrapper)
            }
        }

        // Current rendered range (may be bigger than the view window).
        d.viewFrom = d.viewTo = doc.first
        d.reportedViewFrom = d.reportedViewTo = doc.first
        // Information about the rendered lines.
        d.view = []
        d.renderedView = null
        // Holds info about a single rendered line when it was rendered
        // for measurement, while not in view.
        d.externalMeasured = null
        // Empty space (in pixels) above the view
        d.viewOffset = 0
        d.lastWrapHeight = d.lastWrapWidth = 0
        d.updateLineNumbers = null

        d.nativeBarWidth = d.barHeight = d.barWidth = 0
        d.scrollbarsClipped = false

        // Used to only resize the line number gutter when necessary (when
        // the amount of lines crosses a boundary that makes its width change)
        d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null
        // Set to true when a non-horizontal-scrolling line widget is
        // added. As an optimization, line widget aligning is skipped when
        // this is false.
        d.alignWidgets = false

        d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null

        // Tracks the maximum line length so that the horizontal scrollbar
        // can be kept static when scrolling.
        d.maxLine = null
        d.maxLineLength = 0
        d.maxLineChanged = false

        // Used for measuring wheel scrolling granularity
        d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null

        // True when shift is held down.
        d.shift = false

        // Used to track whether anything happened since the context menu
        // was opened.
        d.selForContextMenu = null

        d.activeTouch = null

        d.gutterSpecs = getGutters(options.gutters, options.lineNumbers)
        renderGutters(d)

        input.init(d)
    }

    // Since the delta values reported on mouse wheel events are
    // unstandardized between browsers and even browser versions, and
    // generally horribly unpredictable, this code starts by measuring
    // the scroll effect that the first few mouse wheel events have,
    // and, from that, detects the way it can convert deltas to pixel
    // offsets afterwards.
    //
    // The reason we want to know the amount a wheel event will scroll
    // is that it gives us a chance to update the display before the
    // actual scrolling happens, reducing flickering.

    var wheelSamples = 0,
        wheelPixelsPerUnit = null
    // Fill in a browser-detected starting value on browsers where we
    // know one. These don't have to be accurate -- the result of them
    // being wrong would just be a slight flicker on the first wheel
    // scroll (if it is large enough).
    if (ie) {
        wheelPixelsPerUnit = -0.53
    } else if (gecko) {
        wheelPixelsPerUnit = 15
    } else if (chrome) {
        wheelPixelsPerUnit = -0.7
    } else if (safari) {
        wheelPixelsPerUnit = -1 / 3
    }

    function wheelEventDelta(e) {
        var dx = e.wheelDeltaX,
            dy = e.wheelDeltaY
        if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) {
            dx = e.detail
        }
        if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) {
            dy = e.detail
        } else if (dy == null) {
            dy = e.wheelDelta
        }
        return { x: dx, y: dy }
    }
    function wheelEventPixels(e) {
        var delta = wheelEventDelta(e)
        delta.x *= wheelPixelsPerUnit
        delta.y *= wheelPixelsPerUnit
        return delta
    }

    function onScrollWheel(cm, e) {
        var delta = wheelEventDelta(e),
            dx = delta.x,
            dy = delta.y
        var pixelsPerUnit = wheelPixelsPerUnit
        if (e.deltaMode === 0) {
            dx = e.deltaX
            dy = e.deltaY
            pixelsPerUnit = 1
        }

        var display = cm.display,
            scroll = display.scroller
        // Quit if there's nothing to scroll here
        var canScrollX = scroll.scrollWidth > scroll.clientWidth
        var canScrollY = scroll.scrollHeight > scroll.clientHeight
        if (!((dx && canScrollX) || (dy && canScrollY))) {
            return
        }

        // Webkit browsers on OS X abort momentum scrolls when the target
        // of the scroll event is removed from the scrollable element.
        // This hack (see related code in patchDisplay) makes sure the
        // element is kept around.
        if (dy && mac && webkit) {
            outer: for (var cur = e.target, view = display.view; cur != scroll; cur = cur.parentNode) {
                for (var i = 0; i < view.length; i++) {
                    if (view[i].node == cur) {
                        cm.display.currentWheelTarget = cur
                        break outer
                    }
                }
            }
        }

        // On some browsers, horizontal scrolling will cause redraws to
        // happen before the gutter has been realigned, causing it to
        // wriggle around in a most unseemly way. When we have an
        // estimated pixels/delta value, we just handle horizontal
        // scrolling entirely here. It'll be slightly off from native, but
        // better than glitching out.
        if (dx && !gecko && !presto && pixelsPerUnit != null) {
            if (dy && canScrollY) {
                updateScrollTop(cm, Math.max(0, scroll.scrollTop + dy * pixelsPerUnit))
            }
            setScrollLeft(cm, Math.max(0, scroll.scrollLeft + dx * pixelsPerUnit))
            // Only prevent default scrolling if vertical scrolling is
            // actually possible. Otherwise, it causes vertical scroll
            // jitter on OSX trackpads when deltaX is small and deltaY
            // is large (issue #3579)
            if (!dy || (dy && canScrollY)) {
                e_preventDefault(e)
            }
            display.wheelStartX = null // Abort measurement, if in progress
            return
        }

        // 'Project' the visible viewport to cover the area that is being
        // scrolled into view (if we know enough to estimate it).
        if (dy && pixelsPerUnit != null) {
            var pixels = dy * pixelsPerUnit
            var top = cm.doc.scrollTop,
                bot = top + display.wrapper.clientHeight
            if (pixels < 0) {
                top = Math.max(0, top + pixels - 50)
            } else {
                bot = Math.min(cm.doc.height, bot + pixels + 50)
            }
            updateDisplaySimple(cm, { top: top, bottom: bot })
        }

        if (wheelSamples < 20 && e.deltaMode !== 0) {
            if (display.wheelStartX == null) {
                display.wheelStartX = scroll.scrollLeft
                display.wheelStartY = scroll.scrollTop
                display.wheelDX = dx
                display.wheelDY = dy
                setTimeout(function () {
                    if (display.wheelStartX == null) {
                        return
                    }
                    var movedX = scroll.scrollLeft - display.wheelStartX
                    var movedY = scroll.scrollTop - display.wheelStartY
                    var sample = (movedY && display.wheelDY && movedY / display.wheelDY) || (movedX && display.wheelDX && movedX / display.wheelDX)
                    display.wheelStartX = display.wheelStartY = null
                    if (!sample) {
                        return
                    }
                    wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1)
                    ++wheelSamples
                }, 200)
            } else {
                display.wheelDX += dx
                display.wheelDY += dy
            }
        }
    }

    // Selection objects are immutable. A new one is created every time
    // the selection changes. A selection is one or more non-overlapping
    // (and non-touching) ranges, sorted, and an integer that indicates
    // which one is the primary selection (the one that's scrolled into
    // view, that getCursor returns, etc).
    var Selection = function (ranges, primIndex) {
        this.ranges = ranges
        this.primIndex = primIndex
    }

    Selection.prototype.primary = function () {
        return this.ranges[this.primIndex]
    }

    Selection.prototype.equals = function (other) {
        if (other == this) {
            return true
        }
        if (other.primIndex != this.primIndex || other.ranges.length != this.ranges.length) {
            return false
        }
        for (var i = 0; i < this.ranges.length; i++) {
            var here = this.ranges[i],
                there = other.ranges[i]
            if (!equalCursorPos(here.anchor, there.anchor) || !equalCursorPos(here.head, there.head)) {
                return false
            }
        }
        return true
    }

    Selection.prototype.deepCopy = function () {
        var out = []
        for (var i = 0; i < this.ranges.length; i++) {
            out[i] = new Range(copyPos(this.ranges[i].anchor), copyPos(this.ranges[i].head))
        }
        return new Selection(out, this.primIndex)
    }

    Selection.prototype.somethingSelected = function () {
        for (var i = 0; i < this.ranges.length; i++) {
            if (!this.ranges[i].empty()) {
                return true
            }
        }
        return false
    }

    Selection.prototype.contains = function (pos, end) {
        if (!end) {
            end = pos
        }
        for (var i = 0; i < this.ranges.length; i++) {
            var range = this.ranges[i]
            if (cmp(end, range.from()) >= 0 && cmp(pos, range.to()) <= 0) {
                return i
            }
        }
        return -1
    }

    var Range = function (anchor, head) {
        this.anchor = anchor
        this.head = head
    }

    Range.prototype.from = function () {
        return minPos(this.anchor, this.head)
    }
    Range.prototype.to = function () {
        return maxPos(this.anchor, this.head)
    }
    Range.prototype.empty = function () {
        return this.head.line == this.anchor.line && this.head.ch == this.anchor.ch
    }

    // Take an unsorted, potentially overlapping set of ranges, and
    // build a selection out of it. 'Consumes' ranges array (modifying
    // it).
    function normalizeSelection(cm, ranges, primIndex) {
        var mayTouch = cm && cm.options.selectionsMayTouch
        var prim = ranges[primIndex]
        ranges.sort(function (a, b) {
            return cmp(a.from(), b.from())
        })
        primIndex = indexOf(ranges, prim)
        for (var i = 1; i < ranges.length; i++) {
            var cur = ranges[i],
                prev = ranges[i - 1]
            var diff = cmp(prev.to(), cur.from())
            if (mayTouch && !cur.empty() ? diff > 0 : diff >= 0) {
                var from = minPos(prev.from(), cur.from()),
                    to = maxPos(prev.to(), cur.to())
                var inv = prev.empty() ? cur.from() == cur.head : prev.from() == prev.head
                if (i <= primIndex) {
                    --primIndex
                }
                ranges.splice(--i, 2, new Range(inv ? to : from, inv ? from : to))
            }
        }
        return new Selection(ranges, primIndex)
    }

    function simpleSelection(anchor, head) {
        return new Selection([new Range(anchor, head || anchor)], 0)
    }

    // Compute the position of the end of a change (its 'to' property
    // refers to the pre-change end).
    function changeEnd(change) {
        if (!change.text) {
            return change.to
        }
        return Pos(change.from.line + change.text.length - 1, lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0))
    }

    // Adjust a position to refer to the post-change position of the
    // same text, or the end of the change if the change covers it.
    function adjustForChange(pos, change) {
        if (cmp(pos, change.from) < 0) {
            return pos
        }
        if (cmp(pos, change.to) <= 0) {
            return changeEnd(change)
        }

        var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1,
            ch = pos.ch
        if (pos.line == change.to.line) {
            ch += changeEnd(change).ch - change.to.ch
        }
        return Pos(line, ch)
    }

    function computeSelAfterChange(doc, change) {
        var out = []
        for (var i = 0; i < doc.sel.ranges.length; i++) {
            var range = doc.sel.ranges[i]
            out.push(new Range(adjustForChange(range.anchor, change), adjustForChange(range.head, change)))
        }
        return normalizeSelection(doc.cm, out, doc.sel.primIndex)
    }

    function offsetPos(pos, old, nw) {
        if (pos.line == old.line) {
            return Pos(nw.line, pos.ch - old.ch + nw.ch)
        } else {
            return Pos(nw.line + (pos.line - old.line), pos.ch)
        }
    }

    // Used by replaceSelections to allow moving the selection to the
    // start or around the replaced test. Hint may be "start" or "around".
    function computeReplacedSel(doc, changes, hint) {
        var out = []
        var oldPrev = Pos(doc.first, 0),
            newPrev = oldPrev
        for (var i = 0; i < changes.length; i++) {
            var change = changes[i]
            var from = offsetPos(change.from, oldPrev, newPrev)
            var to = offsetPos(changeEnd(change), oldPrev, newPrev)
            oldPrev = change.to
            newPrev = to
            if (hint == 'around') {
                var range = doc.sel.ranges[i],
                    inv = cmp(range.head, range.anchor) < 0
                out[i] = new Range(inv ? to : from, inv ? from : to)
            } else {
                out[i] = new Range(from, from)
            }
        }
        return new Selection(out, doc.sel.primIndex)
    }

    // Used to get the editor into a consistent state again when options change.

    function loadMode(cm) {
        cm.doc.mode = getMode(cm.options, cm.doc.modeOption)
        resetModeState(cm)
    }

    function resetModeState(cm) {
        cm.doc.iter(function (line) {
            if (line.stateAfter) {
                line.stateAfter = null
            }
            if (line.styles) {
                line.styles = null
            }
        })
        cm.doc.modeFrontier = cm.doc.highlightFrontier = cm.doc.first
        startWorker(cm, 100)
        cm.state.modeGen++
        if (cm.curOp) {
            regChange(cm)
        }
    }

    // DOCUMENT DATA STRUCTURE

    // By default, updates that start and end at the beginning of a line
    // are treated specially, in order to make the association of line
    // widgets and marker elements with the text behave more intuitive.
    function isWholeLineUpdate(doc, change) {
        return change.from.ch == 0 && change.to.ch == 0 && lst(change.text) == '' && (!doc.cm || doc.cm.options.wholeLineUpdateBefore)
    }

    // Perform a change on the document data structure.
    function updateDoc(doc, change, markedSpans, estimateHeight) {
        function spansFor(n) {
            return markedSpans ? markedSpans[n] : null
        }
        function update(line, text, spans) {
            updateLine(line, text, spans, estimateHeight)
            signalLater(line, 'change', line, change)
        }
        function linesFor(start, end) {
            var result = []
            for (var i = start; i < end; ++i) {
                result.push(new Line(text[i], spansFor(i), estimateHeight))
            }
            return result
        }

        var from = change.from,
            to = change.to,
            text = change.text
        var firstLine = getLine(doc, from.line),
            lastLine = getLine(doc, to.line)
        var lastText = lst(text),
            lastSpans = spansFor(text.length - 1),
            nlines = to.line - from.line

        // Adjust the line structure
        if (change.full) {
            doc.insert(0, linesFor(0, text.length))
            doc.remove(text.length, doc.size - text.length)
        } else if (isWholeLineUpdate(doc, change)) {
            // This is a whole-line replace. Treated specially to make
            // sure line objects move the way they are supposed to.
            var added = linesFor(0, text.length - 1)
            update(lastLine, lastLine.text, lastSpans)
            if (nlines) {
                doc.remove(from.line, nlines)
            }
            if (added.length) {
                doc.insert(from.line, added)
            }
        } else if (firstLine == lastLine) {
            if (text.length == 1) {
                update(firstLine, firstLine.text.slice(0, from.ch) + lastText + firstLine.text.slice(to.ch), lastSpans)
            } else {
                var added$1 = linesFor(1, text.length - 1)
                added$1.push(new Line(lastText + firstLine.text.slice(to.ch), lastSpans, estimateHeight))
                update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0))
                doc.insert(from.line + 1, added$1)
            }
        } else if (text.length == 1) {
            update(firstLine, firstLine.text.slice(0, from.ch) + text[0] + lastLine.text.slice(to.ch), spansFor(0))
            doc.remove(from.line + 1, nlines)
        } else {
            update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0))
            update(lastLine, lastText + lastLine.text.slice(to.ch), lastSpans)
            var added$2 = linesFor(1, text.length - 1)
            if (nlines > 1) {
                doc.remove(from.line + 1, nlines - 1)
            }
            doc.insert(from.line + 1, added$2)
        }

        signalLater(doc, 'change', doc, change)
    }

    // Call f for all linked documents.
    function linkedDocs(doc, f, sharedHistOnly) {
        function propagate(doc, skip, sharedHist) {
            if (doc.linked) {
                for (var i = 0; i < doc.linked.length; ++i) {
                    var rel = doc.linked[i]
                    if (rel.doc == skip) {
                        continue
                    }
                    var shared = sharedHist && rel.sharedHist
                    if (sharedHistOnly && !shared) {
                        continue
                    }
                    f(rel.doc, shared)
                    propagate(rel.doc, doc, shared)
                }
            }
        }
        propagate(doc, null, true)
    }

    // Attach a document to an editor.
    function attachDoc(cm, doc) {
        if (doc.cm) {
            throw new Error('This document is already in use.')
        }
        cm.doc = doc
        doc.cm = cm
        estimateLineHeights(cm)
        loadMode(cm)
        setDirectionClass(cm)
        cm.options.direction = doc.direction
        if (!cm.options.lineWrapping) {
            findMaxLine(cm)
        }
        cm.options.mode = doc.modeOption
        regChange(cm)
    }

    function setDirectionClass(cm) {
        ;(cm.doc.direction == 'rtl' ? addClass : rmClass)(cm.display.lineDiv, 'CodeMirror-rtl')
    }

    function directionChanged(cm) {
        runInOp(cm, function () {
            setDirectionClass(cm)
            regChange(cm)
        })
    }

    function History(prev) {
        // Arrays of change events and selections. Doing something adds an
        // event to done and clears undo. Undoing moves events from done
        // to undone, redoing moves them in the other direction.
        this.done = []
        this.undone = []
        this.undoDepth = prev ? prev.undoDepth : Infinity
        // Used to track when changes can be merged into a single undo
        // event
        this.lastModTime = this.lastSelTime = 0
        this.lastOp = this.lastSelOp = null
        this.lastOrigin = this.lastSelOrigin = null
        // Used by the isClean() method
        this.generation = this.maxGeneration = prev ? prev.maxGeneration : 1
    }

    // Create a history change event from an updateDoc-style change
    // object.
    function historyChangeFromChange(doc, change) {
        var histChange = { from: copyPos(change.from), to: changeEnd(change), text: getBetween(doc, change.from, change.to) }
        attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1)
        linkedDocs(
            doc,
            function (doc) {
                return attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1)
            },
            true
        )
        return histChange
    }

    // Pop all selection events off the end of a history array. Stop at
    // a change event.
    function clearSelectionEvents(array) {
        while (array.length) {
            var last = lst(array)
            if (last.ranges) {
                array.pop()
            } else {
                break
            }
        }
    }

    // Find the top change event in the history. Pop off selection
    // events that are in the way.
    function lastChangeEvent(hist, force) {
        if (force) {
            clearSelectionEvents(hist.done)
            return lst(hist.done)
        } else if (hist.done.length && !lst(hist.done).ranges) {
            return lst(hist.done)
        } else if (hist.done.length > 1 && !hist.done[hist.done.length - 2].ranges) {
            hist.done.pop()
            return lst(hist.done)
        }
    }

    // Register a change in the history. Merges changes that are within
    // a single operation, or are close together with an origin that
    // allows merging (starting with "+") into a single event.
    function addChangeToHistory(doc, change, selAfter, opId) {
        var hist = doc.history
        hist.undone.length = 0
        var time = +new Date(),
            cur
        var last

        if (
            (hist.lastOp == opId ||
                (hist.lastOrigin == change.origin &&
                    change.origin &&
                    ((change.origin.charAt(0) == '+' && hist.lastModTime > time - (doc.cm ? doc.cm.options.historyEventDelay : 500)) || change.origin.charAt(0) == '*'))) &&
            (cur = lastChangeEvent(hist, hist.lastOp == opId))
        ) {
            // Merge this change into the last event
            last = lst(cur.changes)
            if (cmp(change.from, change.to) == 0 && cmp(change.from, last.to) == 0) {
                // Optimized case for simple insertion -- don't want to add
                // new changesets for every character typed
                last.to = changeEnd(change)
            } else {
                // Add new sub-event
                cur.changes.push(historyChangeFromChange(doc, change))
            }
        } else {
            // Can not be merged, start a new event.
            var before = lst(hist.done)
            if (!before || !before.ranges) {
                pushSelectionToHistory(doc.sel, hist.done)
            }
            cur = { changes: [historyChangeFromChange(doc, change)], generation: hist.generation }
            hist.done.push(cur)
            while (hist.done.length > hist.undoDepth) {
                hist.done.shift()
                if (!hist.done[0].ranges) {
                    hist.done.shift()
                }
            }
        }
        hist.done.push(selAfter)
        hist.generation = ++hist.maxGeneration
        hist.lastModTime = hist.lastSelTime = time
        hist.lastOp = hist.lastSelOp = opId
        hist.lastOrigin = hist.lastSelOrigin = change.origin

        if (!last) {
            signal(doc, 'historyAdded')
        }
    }

    function selectionEventCanBeMerged(doc, origin, prev, sel) {
        var ch = origin.charAt(0)
        return (
            ch == '*' ||
            (ch == '+' &&
                prev.ranges.length == sel.ranges.length &&
                prev.somethingSelected() == sel.somethingSelected() &&
                new Date() - doc.history.lastSelTime <= (doc.cm ? doc.cm.options.historyEventDelay : 500))
        )
    }

    // Called whenever the selection changes, sets the new selection as
    // the pending selection in the history, and pushes the old pending
    // selection into the 'done' array when it was significantly
    // different (in number of selected ranges, emptiness, or time).
    function addSelectionToHistory(doc, sel, opId, options) {
        var hist = doc.history,
            origin = options && options.origin

        // A new event is started when the previous origin does not match
        // the current, or the origins don't allow matching. Origins
        // starting with * are always merged, those starting with + are
        // merged when similar and close together in time.
        if (
            opId == hist.lastSelOp ||
            (origin && hist.lastSelOrigin == origin && ((hist.lastModTime == hist.lastSelTime && hist.lastOrigin == origin) || selectionEventCanBeMerged(doc, origin, lst(hist.done), sel)))
        ) {
            hist.done[hist.done.length - 1] = sel
        } else {
            pushSelectionToHistory(sel, hist.done)
        }

        hist.lastSelTime = +new Date()
        hist.lastSelOrigin = origin
        hist.lastSelOp = opId
        if (options && options.clearRedo !== false) {
            clearSelectionEvents(hist.undone)
        }
    }

    function pushSelectionToHistory(sel, dest) {
        var top = lst(dest)
        if (!(top && top.ranges && top.equals(sel))) {
            dest.push(sel)
        }
    }

    // Used to store marked span information in the history.
    function attachLocalSpans(doc, change, from, to) {
        var existing = change['spans_' + doc.id],
            n = 0
        doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), function (line) {
            if (line.markedSpans) {
                ;(existing || (existing = change['spans_' + doc.id] = {}))[n] = line.markedSpans
            }
            ++n
        })
    }

    // When un/re-doing restores text containing marked spans, those
    // that have been explicitly cleared should not be restored.
    function removeClearedSpans(spans) {
        if (!spans) {
            return null
        }
        var out
        for (var i = 0; i < spans.length; ++i) {
            if (spans[i].marker.explicitlyCleared) {
                if (!out) {
                    out = spans.slice(0, i)
                }
            } else if (out) {
                out.push(spans[i])
            }
        }
        return !out ? spans : out.length ? out : null
    }

    // Retrieve and filter the old marked spans stored in a change event.
    function getOldSpans(doc, change) {
        var found = change['spans_' + doc.id]
        if (!found) {
            return null
        }
        var nw = []
        for (var i = 0; i < change.text.length; ++i) {
            nw.push(removeClearedSpans(found[i]))
        }
        return nw
    }

    // Used for un/re-doing changes from the history. Combines the
    // result of computing the existing spans with the set of spans that
    // existed in the history (so that deleting around a span and then
    // undoing brings back the span).
    function mergeOldSpans(doc, change) {
        var old = getOldSpans(doc, change)
        var stretched = stretchSpansOverChange(doc, change)
        if (!old) {
            return stretched
        }
        if (!stretched) {
            return old
        }

        for (var i = 0; i < old.length; ++i) {
            var oldCur = old[i],
                stretchCur = stretched[i]
            if (oldCur && stretchCur) {
                spans: for (var j = 0; j < stretchCur.length; ++j) {
                    var span = stretchCur[j]
                    for (var k = 0; k < oldCur.length; ++k) {
                        if (oldCur[k].marker == span.marker) {
                            continue spans
                        }
                    }
                    oldCur.push(span)
                }
            } else if (stretchCur) {
                old[i] = stretchCur
            }
        }
        return old
    }

    // Used both to provide a JSON-safe object in .getHistory, and, when
    // detaching a document, to split the history in two
    function copyHistoryArray(events, newGroup, instantiateSel) {
        var copy = []
        for (var i = 0; i < events.length; ++i) {
            var event = events[i]
            if (event.ranges) {
                copy.push(instantiateSel ? Selection.prototype.deepCopy.call(event) : event)
                continue
            }
            var changes = event.changes,
                newChanges = []
            copy.push({ changes: newChanges })
            for (var j = 0; j < changes.length; ++j) {
                var change = changes[j],
                    m = void 0
                newChanges.push({ from: change.from, to: change.to, text: change.text })
                if (newGroup) {
                    for (var prop in change) {
                        if ((m = prop.match(/^spans_(\d+)$/))) {
                            if (indexOf(newGroup, Number(m[1])) > -1) {
                                lst(newChanges)[prop] = change[prop]
                                delete change[prop]
                            }
                        }
                    }
                }
            }
        }
        return copy
    }

    // The 'scroll' parameter given to many of these indicated whether
    // the new cursor position should be scrolled into view after
    // modifying the selection.

    // If shift is held or the extend flag is set, extends a range to
    // include a given position (and optionally a second position).
    // Otherwise, simply returns the range between the given positions.
    // Used for cursor motion and such.
    function extendRange(range, head, other, extend) {
        if (extend) {
            var anchor = range.anchor
            if (other) {
                var posBefore = cmp(head, anchor) < 0
                if (posBefore != cmp(other, anchor) < 0) {
                    anchor = head
                    head = other
                } else if (posBefore != cmp(head, other) < 0) {
                    head = other
                }
            }
            return new Range(anchor, head)
        } else {
            return new Range(other || head, head)
        }
    }

    // Extend the primary selection range, discard the rest.
    function extendSelection(doc, head, other, options, extend) {
        if (extend == null) {
            extend = doc.cm && (doc.cm.display.shift || doc.extend)
        }
        setSelection(doc, new Selection([extendRange(doc.sel.primary(), head, other, extend)], 0), options)
    }

    // Extend all selections (pos is an array of selections with length
    // equal the number of selections)
    function extendSelections(doc, heads, options) {
        var out = []
        var extend = doc.cm && (doc.cm.display.shift || doc.extend)
        for (var i = 0; i < doc.sel.ranges.length; i++) {
            out[i] = extendRange(doc.sel.ranges[i], heads[i], null, extend)
        }
        var newSel = normalizeSelection(doc.cm, out, doc.sel.primIndex)
        setSelection(doc, newSel, options)
    }

    // Updates a single range in the selection.
    function replaceOneSelection(doc, i, range, options) {
        var ranges = doc.sel.ranges.slice(0)
        ranges[i] = range
        setSelection(doc, normalizeSelection(doc.cm, ranges, doc.sel.primIndex), options)
    }

    // Reset the selection to a single range.
    function setSimpleSelection(doc, anchor, head, options) {
        setSelection(doc, simpleSelection(anchor, head), options)
    }

    // Give beforeSelectionChange handlers a change to influence a
    // selection update.
    function filterSelectionChange(doc, sel, options) {
        var obj = {
            ranges: sel.ranges,
            update: function (ranges) {
                this.ranges = []
                for (var i = 0; i < ranges.length; i++) {
                    this.ranges[i] = new Range(clipPos(doc, ranges[i].anchor), clipPos(doc, ranges[i].head))
                }
            },
            origin: options && options.origin,
        }
        signal(doc, 'beforeSelectionChange', doc, obj)
        if (doc.cm) {
            signal(doc.cm, 'beforeSelectionChange', doc.cm, obj)
        }
        if (obj.ranges != sel.ranges) {
            return normalizeSelection(doc.cm, obj.ranges, obj.ranges.length - 1)
        } else {
            return sel
        }
    }

    function setSelectionReplaceHistory(doc, sel, options) {
        var done = doc.history.done,
            last = lst(done)
        if (last && last.ranges) {
            done[done.length - 1] = sel
            setSelectionNoUndo(doc, sel, options)
        } else {
            setSelection(doc, sel, options)
        }
    }

    // Set a new selection.
    function setSelection(doc, sel, options) {
        setSelectionNoUndo(doc, sel, options)
        addSelectionToHistory(doc, doc.sel, doc.cm ? doc.cm.curOp.id : NaN, options)
    }

    function setSelectionNoUndo(doc, sel, options) {
        if (hasHandler(doc, 'beforeSelectionChange') || (doc.cm && hasHandler(doc.cm, 'beforeSelectionChange'))) {
            sel = filterSelectionChange(doc, sel, options)
        }

        var bias = (options && options.bias) || (cmp(sel.primary().head, doc.sel.primary().head) < 0 ? -1 : 1)
        setSelectionInner(doc, skipAtomicInSelection(doc, sel, bias, true))

        if (!(options && options.scroll === false) && doc.cm && doc.cm.getOption('readOnly') != 'nocursor') {
            ensureCursorVisible(doc.cm)
        }
    }

    function setSelectionInner(doc, sel) {
        if (sel.equals(doc.sel)) {
            return
        }

        doc.sel = sel

        if (doc.cm) {
            doc.cm.curOp.updateInput = 1
            doc.cm.curOp.selectionChanged = true
            signalCursorActivity(doc.cm)
        }
        signalLater(doc, 'cursorActivity', doc)
    }

    // Verify that the selection does not partially select any atomic
    // marked ranges.
    function reCheckSelection(doc) {
        setSelectionInner(doc, skipAtomicInSelection(doc, doc.sel, null, false))
    }

    // Return a selection that does not partially select any atomic
    // ranges.
    function skipAtomicInSelection(doc, sel, bias, mayClear) {
        var out
        for (var i = 0; i < sel.ranges.length; i++) {
            var range = sel.ranges[i]
            var old = sel.ranges.length == doc.sel.ranges.length && doc.sel.ranges[i]
            var newAnchor = skipAtomic(doc, range.anchor, old && old.anchor, bias, mayClear)
            var newHead = skipAtomic(doc, range.head, old && old.head, bias, mayClear)
            if (out || newAnchor != range.anchor || newHead != range.head) {
                if (!out) {
                    out = sel.ranges.slice(0, i)
                }
                out[i] = new Range(newAnchor, newHead)
            }
        }
        return out ? normalizeSelection(doc.cm, out, sel.primIndex) : sel
    }

    function skipAtomicInner(doc, pos, oldPos, dir, mayClear) {
        var line = getLine(doc, pos.line)
        if (line.markedSpans) {
            for (var i = 0; i < line.markedSpans.length; ++i) {
                var sp = line.markedSpans[i],
                    m = sp.marker

                // Determine if we should prevent the cursor being placed to the left/right of an atomic marker
                // Historically this was determined using the inclusiveLeft/Right option, but the new way to control it
                // is with selectLeft/Right
                var preventCursorLeft = 'selectLeft' in m ? !m.selectLeft : m.inclusiveLeft
                var preventCursorRight = 'selectRight' in m ? !m.selectRight : m.inclusiveRight

                if ((sp.from == null || (preventCursorLeft ? sp.from <= pos.ch : sp.from < pos.ch)) && (sp.to == null || (preventCursorRight ? sp.to >= pos.ch : sp.to > pos.ch))) {
                    if (mayClear) {
                        signal(m, 'beforeCursorEnter')
                        if (m.explicitlyCleared) {
                            if (!line.markedSpans) {
                                break
                            } else {
                                --i
                                continue
                            }
                        }
                    }
                    if (!m.atomic) {
                        continue
                    }

                    if (oldPos) {
                        var near = m.find(dir < 0 ? 1 : -1),
                            diff = void 0
                        if (dir < 0 ? preventCursorRight : preventCursorLeft) {
                            near = movePos(doc, near, -dir, near && near.line == pos.line ? line : null)
                        }
                        if (near && near.line == pos.line && (diff = cmp(near, oldPos)) && (dir < 0 ? diff < 0 : diff > 0)) {
                            return skipAtomicInner(doc, near, pos, dir, mayClear)
                        }
                    }

                    var far = m.find(dir < 0 ? -1 : 1)
                    if (dir < 0 ? preventCursorLeft : preventCursorRight) {
                        far = movePos(doc, far, dir, far.line == pos.line ? line : null)
                    }
                    return far ? skipAtomicInner(doc, far, pos, dir, mayClear) : null
                }
            }
        }
        return pos
    }

    // Ensure a given position is not inside an atomic range.
    function skipAtomic(doc, pos, oldPos, bias, mayClear) {
        var dir = bias || 1
        var found =
            skipAtomicInner(doc, pos, oldPos, dir, mayClear) ||
            (!mayClear && skipAtomicInner(doc, pos, oldPos, dir, true)) ||
            skipAtomicInner(doc, pos, oldPos, -dir, mayClear) ||
            (!mayClear && skipAtomicInner(doc, pos, oldPos, -dir, true))
        if (!found) {
            doc.cantEdit = true
            return Pos(doc.first, 0)
        }
        return found
    }

    function movePos(doc, pos, dir, line) {
        if (dir < 0 && pos.ch == 0) {
            if (pos.line > doc.first) {
                return clipPos(doc, Pos(pos.line - 1))
            } else {
                return null
            }
        } else if (dir > 0 && pos.ch == (line || getLine(doc, pos.line)).text.length) {
            if (pos.line < doc.first + doc.size - 1) {
                return Pos(pos.line + 1, 0)
            } else {
                return null
            }
        } else {
            return new Pos(pos.line, pos.ch + dir)
        }
    }

    function selectAll(cm) {
        cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()), sel_dontScroll)
    }

    // UPDATING

    // Allow "beforeChange" event handlers to influence a change
    function filterChange(doc, change, update) {
        var obj = {
            canceled: false,
            from: change.from,
            to: change.to,
            text: change.text,
            origin: change.origin,
            cancel: function () {
                return (obj.canceled = true)
            },
        }
        if (update) {
            obj.update = function (from, to, text, origin) {
                if (from) {
                    obj.from = clipPos(doc, from)
                }
                if (to) {
                    obj.to = clipPos(doc, to)
                }
                if (text) {
                    obj.text = text
                }
                if (origin !== undefined) {
                    obj.origin = origin
                }
            }
        }
        signal(doc, 'beforeChange', doc, obj)
        if (doc.cm) {
            signal(doc.cm, 'beforeChange', doc.cm, obj)
        }

        if (obj.canceled) {
            if (doc.cm) {
                doc.cm.curOp.updateInput = 2
            }
            return null
        }
        return { from: obj.from, to: obj.to, text: obj.text, origin: obj.origin }
    }

    // Apply a change to a document, and add it to the document's
    // history, and propagating it to all linked documents.
    function makeChange(doc, change, ignoreReadOnly) {
        if (doc.cm) {
            if (!doc.cm.curOp) {
                return operation(doc.cm, makeChange)(doc, change, ignoreReadOnly)
            }
            if (doc.cm.state.suppressEdits) {
                return
            }
        }

        if (hasHandler(doc, 'beforeChange') || (doc.cm && hasHandler(doc.cm, 'beforeChange'))) {
            change = filterChange(doc, change, true)
            if (!change) {
                return
            }
        }

        // Possibly split or suppress the update based on the presence
        // of read-only spans in its range.
        var split = sawReadOnlySpans && !ignoreReadOnly && removeReadOnlyRanges(doc, change.from, change.to)
        if (split) {
            for (var i = split.length - 1; i >= 0; --i) {
                makeChangeInner(doc, { from: split[i].from, to: split[i].to, text: i ? [''] : change.text, origin: change.origin })
            }
        } else {
            makeChangeInner(doc, change)
        }
    }

    function makeChangeInner(doc, change) {
        if (change.text.length == 1 && change.text[0] == '' && cmp(change.from, change.to) == 0) {
            return
        }
        var selAfter = computeSelAfterChange(doc, change)
        addChangeToHistory(doc, change, selAfter, doc.cm ? doc.cm.curOp.id : NaN)

        makeChangeSingleDoc(doc, change, selAfter, stretchSpansOverChange(doc, change))
        var rebased = []

        linkedDocs(doc, function (doc, sharedHist) {
            if (!sharedHist && indexOf(rebased, doc.history) == -1) {
                rebaseHist(doc.history, change)
                rebased.push(doc.history)
            }
            makeChangeSingleDoc(doc, change, null, stretchSpansOverChange(doc, change))
        })
    }

    // Revert a change stored in a document's history.
    function makeChangeFromHistory(doc, type, allowSelectionOnly) {
        var suppress = doc.cm && doc.cm.state.suppressEdits
        if (suppress && !allowSelectionOnly) {
            return
        }

        var hist = doc.history,
            event,
            selAfter = doc.sel
        var source = type == 'undo' ? hist.done : hist.undone,
            dest = type == 'undo' ? hist.undone : hist.done

        // Verify that there is a useable event (so that ctrl-z won't
        // needlessly clear selection events)
        var i = 0
        for (; i < source.length; i++) {
            event = source[i]
            if (allowSelectionOnly ? event.ranges && !event.equals(doc.sel) : !event.ranges) {
                break
            }
        }
        if (i == source.length) {
            return
        }
        hist.lastOrigin = hist.lastSelOrigin = null

        for (;;) {
            event = source.pop()
            if (event.ranges) {
                pushSelectionToHistory(event, dest)
                if (allowSelectionOnly && !event.equals(doc.sel)) {
                    setSelection(doc, event, { clearRedo: false })
                    return
                }
                selAfter = event
            } else if (suppress) {
                source.push(event)
                return
            } else {
                break
            }
        }

        // Build up a reverse change object to add to the opposite history
        // stack (redo when undoing, and vice versa).
        var antiChanges = []
        pushSelectionToHistory(selAfter, dest)
        dest.push({ changes: antiChanges, generation: hist.generation })
        hist.generation = event.generation || ++hist.maxGeneration

        var filter = hasHandler(doc, 'beforeChange') || (doc.cm && hasHandler(doc.cm, 'beforeChange'))

        var loop = function (i) {
            var change = event.changes[i]
            change.origin = type
            if (filter && !filterChange(doc, change, false)) {
                source.length = 0
                return {}
            }

            antiChanges.push(historyChangeFromChange(doc, change))

            var after = i ? computeSelAfterChange(doc, change) : lst(source)
            makeChangeSingleDoc(doc, change, after, mergeOldSpans(doc, change))
            if (!i && doc.cm) {
                doc.cm.scrollIntoView({ from: change.from, to: changeEnd(change) })
            }
            var rebased = []

            // Propagate to the linked documents
            linkedDocs(doc, function (doc, sharedHist) {
                if (!sharedHist && indexOf(rebased, doc.history) == -1) {
                    rebaseHist(doc.history, change)
                    rebased.push(doc.history)
                }
                makeChangeSingleDoc(doc, change, null, mergeOldSpans(doc, change))
            })
        }

        for (var i$1 = event.changes.length - 1; i$1 >= 0; --i$1) {
            var returned = loop(i$1)

            if (returned) return returned.v
        }
    }

    // Sub-views need their line numbers shifted when text is added
    // above or below them in the parent document.
    function shiftDoc(doc, distance) {
        if (distance == 0) {
            return
        }
        doc.first += distance
        doc.sel = new Selection(
            map(doc.sel.ranges, function (range) {
                return new Range(Pos(range.anchor.line + distance, range.anchor.ch), Pos(range.head.line + distance, range.head.ch))
            }),
            doc.sel.primIndex
        )
        if (doc.cm) {
            regChange(doc.cm, doc.first, doc.first - distance, distance)
            for (var d = doc.cm.display, l = d.viewFrom; l < d.viewTo; l++) {
                regLineChange(doc.cm, l, 'gutter')
            }
        }
    }

    // More lower-level change function, handling only a single document
    // (not linked ones).
    function makeChangeSingleDoc(doc, change, selAfter, spans) {
        if (doc.cm && !doc.cm.curOp) {
            return operation(doc.cm, makeChangeSingleDoc)(doc, change, selAfter, spans)
        }

        if (change.to.line < doc.first) {
            shiftDoc(doc, change.text.length - 1 - (change.to.line - change.from.line))
            return
        }
        if (change.from.line > doc.lastLine()) {
            return
        }

        // Clip the change to the size of this doc
        if (change.from.line < doc.first) {
            var shift = change.text.length - 1 - (doc.first - change.from.line)
            shiftDoc(doc, shift)
            change = { from: Pos(doc.first, 0), to: Pos(change.to.line + shift, change.to.ch), text: [lst(change.text)], origin: change.origin }
        }
        var last = doc.lastLine()
        if (change.to.line > last) {
            change = { from: change.from, to: Pos(last, getLine(doc, last).text.length), text: [change.text[0]], origin: change.origin }
        }

        change.removed = getBetween(doc, change.from, change.to)

        if (!selAfter) {
            selAfter = computeSelAfterChange(doc, change)
        }
        if (doc.cm) {
            makeChangeSingleDocInEditor(doc.cm, change, spans)
        } else {
            updateDoc(doc, change, spans)
        }
        setSelectionNoUndo(doc, selAfter, sel_dontScroll)

        if (doc.cantEdit && skipAtomic(doc, Pos(doc.firstLine(), 0))) {
            doc.cantEdit = false
        }
    }

    // Handle the interaction of a change to a document with the editor
    // that this document is part of.
    function makeChangeSingleDocInEditor(cm, change, spans) {
        var doc = cm.doc,
            display = cm.display,
            from = change.from,
            to = change.to

        var recomputeMaxLength = false,
            checkWidthStart = from.line
        if (!cm.options.lineWrapping) {
            checkWidthStart = lineNo(visualLine(getLine(doc, from.line)))
            doc.iter(checkWidthStart, to.line + 1, function (line) {
                if (line == display.maxLine) {
                    recomputeMaxLength = true
                    return true
                }
            })
        }

        if (doc.sel.contains(change.from, change.to) > -1) {
            signalCursorActivity(cm)
        }

        updateDoc(doc, change, spans, estimateHeight(cm))

        if (!cm.options.lineWrapping) {
            doc.iter(checkWidthStart, from.line + change.text.length, function (line) {
                var len = lineLength(line)
                if (len > display.maxLineLength) {
                    display.maxLine = line
                    display.maxLineLength = len
                    display.maxLineChanged = true
                    recomputeMaxLength = false
                }
            })
            if (recomputeMaxLength) {
                cm.curOp.updateMaxLine = true
            }
        }

        retreatFrontier(doc, from.line)
        startWorker(cm, 400)

        var lendiff = change.text.length - (to.line - from.line) - 1
        // Remember that these lines changed, for updating the display
        if (change.full) {
            regChange(cm)
        } else if (from.line == to.line && change.text.length == 1 && !isWholeLineUpdate(cm.doc, change)) {
            regLineChange(cm, from.line, 'text')
        } else {
            regChange(cm, from.line, to.line + 1, lendiff)
        }

        var changesHandler = hasHandler(cm, 'changes'),
            changeHandler = hasHandler(cm, 'change')
        if (changeHandler || changesHandler) {
            var obj = {
                from: from,
                to: to,
                text: change.text,
                removed: change.removed,
                origin: change.origin,
            }
            if (changeHandler) {
                signalLater(cm, 'change', cm, obj)
            }
            if (changesHandler) {
                ;(cm.curOp.changeObjs || (cm.curOp.changeObjs = [])).push(obj)
            }
        }
        cm.display.selForContextMenu = null
    }

    function replaceRange(doc, code, from, to, origin) {
        var assign

        if (!to) {
            to = from
        }
        if (cmp(to, from) < 0) {
            ;(assign = [to, from]), (from = assign[0]), (to = assign[1])
        }
        if (typeof code == 'string') {
            code = doc.splitLines(code)
        }
        makeChange(doc, { from: from, to: to, text: code, origin: origin })
    }

    // Rebasing/resetting history to deal with externally-sourced changes

    function rebaseHistSelSingle(pos, from, to, diff) {
        if (to < pos.line) {
            pos.line += diff
        } else if (from < pos.line) {
            pos.line = from
            pos.ch = 0
        }
    }

    // Tries to rebase an array of history events given a change in the
    // document. If the change touches the same lines as the event, the
    // event, and everything 'behind' it, is discarded. If the change is
    // before the event, the event's positions are updated. Uses a
    // copy-on-write scheme for the positions, to avoid having to
    // reallocate them all on every rebase, but also avoid problems with
    // shared position objects being unsafely updated.
    function rebaseHistArray(array, from, to, diff) {
        for (var i = 0; i < array.length; ++i) {
            var sub = array[i],
                ok = true
            if (sub.ranges) {
                if (!sub.copied) {
                    sub = array[i] = sub.deepCopy()
                    sub.copied = true
                }
                for (var j = 0; j < sub.ranges.length; j++) {
                    rebaseHistSelSingle(sub.ranges[j].anchor, from, to, diff)
                    rebaseHistSelSingle(sub.ranges[j].head, from, to, diff)
                }
                continue
            }
            for (var j$1 = 0; j$1 < sub.changes.length; ++j$1) {
                var cur = sub.changes[j$1]
                if (to < cur.from.line) {
                    cur.from = Pos(cur.from.line + diff, cur.from.ch)
                    cur.to = Pos(cur.to.line + diff, cur.to.ch)
                } else if (from <= cur.to.line) {
                    ok = false
                    break
                }
            }
            if (!ok) {
                array.splice(0, i + 1)
                i = 0
            }
        }
    }

    function rebaseHist(hist, change) {
        var from = change.from.line,
            to = change.to.line,
            diff = change.text.length - (to - from) - 1
        rebaseHistArray(hist.done, from, to, diff)
        rebaseHistArray(hist.undone, from, to, diff)
    }

    // Utility for applying a change to a line by handle or number,
    // returning the number and optionally registering the line as
    // changed.
    function changeLine(doc, handle, changeType, op) {
        var no = handle,
            line = handle
        if (typeof handle == 'number') {
            line = getLine(doc, clipLine(doc, handle))
        } else {
            no = lineNo(handle)
        }
        if (no == null) {
            return null
        }
        if (op(line, no) && doc.cm) {
            regLineChange(doc.cm, no, changeType)
        }
        return line
    }

    // The document is represented as a BTree consisting of leaves, with
    // chunk of lines in them, and branches, with up to ten leaves or
    // other branch nodes below them. The top node is always a branch
    // node, and is the document object itself (meaning it has
    // additional methods and properties).
    //
    // All nodes have parent links. The tree is used both to go from
    // line numbers to line objects, and to go from objects to numbers.
    // It also indexes by height, and is used to convert between height
    // and line object, and to find the total height of the document.
    //
    // See also http://marijnhaverbeke.nl/blog/codemirror-line-tree.html

    function LeafChunk(lines) {
        this.lines = lines
        this.parent = null
        var height = 0
        for (var i = 0; i < lines.length; ++i) {
            lines[i].parent = this
            height += lines[i].height
        }
        this.height = height
    }

    LeafChunk.prototype = {
        chunkSize: function () {
            return this.lines.length
        },

        // Remove the n lines at offset 'at'.
        removeInner: function (at, n) {
            for (var i = at, e = at + n; i < e; ++i) {
                var line = this.lines[i]
                this.height -= line.height
                cleanUpLine(line)
                signalLater(line, 'delete')
            }
            this.lines.splice(at, n)
        },

        // Helper used to collapse a small branch into a single leaf.
        collapse: function (lines) {
            lines.push.apply(lines, this.lines)
        },

        // Insert the given array of lines at offset 'at', count them as
        // having the given height.
        insertInner: function (at, lines, height) {
            this.height += height
            this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at))
            for (var i = 0; i < lines.length; ++i) {
                lines[i].parent = this
            }
        },

        // Used to iterate over a part of the tree.
        iterN: function (at, n, op) {
            for (var e = at + n; at < e; ++at) {
                if (op(this.lines[at])) {
                    return true
                }
            }
        },
    }

    function BranchChunk(children) {
        this.children = children
        var size = 0,
            height = 0
        for (var i = 0; i < children.length; ++i) {
            var ch = children[i]
            size += ch.chunkSize()
            height += ch.height
            ch.parent = this
        }
        this.size = size
        this.height = height
        this.parent = null
    }

    BranchChunk.prototype = {
        chunkSize: function () {
            return this.size
        },

        removeInner: function (at, n) {
            this.size -= n
            for (var i = 0; i < this.children.length; ++i) {
                var child = this.children[i],
                    sz = child.chunkSize()
                if (at < sz) {
                    var rm = Math.min(n, sz - at),
                        oldHeight = child.height
                    child.removeInner(at, rm)
                    this.height -= oldHeight - child.height
                    if (sz == rm) {
                        this.children.splice(i--, 1)
                        child.parent = null
                    }
                    if ((n -= rm) == 0) {
                        break
                    }
                    at = 0
                } else {
                    at -= sz
                }
            }
            // If the result is smaller than 25 lines, ensure that it is a
            // single leaf node.
            if (this.size - n < 25 && (this.children.length > 1 || !(this.children[0] instanceof LeafChunk))) {
                var lines = []
                this.collapse(lines)
                this.children = [new LeafChunk(lines)]
                this.children[0].parent = this
            }
        },

        collapse: function (lines) {
            for (var i = 0; i < this.children.length; ++i) {
                this.children[i].collapse(lines)
            }
        },

        insertInner: function (at, lines, height) {
            this.size += lines.length
            this.height += height
            for (var i = 0; i < this.children.length; ++i) {
                var child = this.children[i],
                    sz = child.chunkSize()
                if (at <= sz) {
                    child.insertInner(at, lines, height)
                    if (child.lines && child.lines.length > 50) {
                        // To avoid memory thrashing when child.lines is huge (e.g. first view of a large file), it's never spliced.
                        // Instead, small slices are taken. They're taken in order because sequential memory accesses are fastest.
                        var remaining = (child.lines.length % 25) + 25
                        for (var pos = remaining; pos < child.lines.length; ) {
                            var leaf = new LeafChunk(child.lines.slice(pos, (pos += 25)))
                            child.height -= leaf.height
                            this.children.splice(++i, 0, leaf)
                            leaf.parent = this
                        }
                        child.lines = child.lines.slice(0, remaining)
                        this.maybeSpill()
                    }
                    break
                }
                at -= sz
            }
        },

        // When a node has grown, check whether it should be split.
        maybeSpill: function () {
            if (this.children.length <= 10) {
                return
            }
            var me = this
            do {
                var spilled = me.children.splice(me.children.length - 5, 5)
                var sibling = new BranchChunk(spilled)
                if (!me.parent) {
                    // Become the parent node
                    var copy = new BranchChunk(me.children)
                    copy.parent = me
                    me.children = [copy, sibling]
                    me = copy
                } else {
                    me.size -= sibling.size
                    me.height -= sibling.height
                    var myIndex = indexOf(me.parent.children, me)
                    me.parent.children.splice(myIndex + 1, 0, sibling)
                }
                sibling.parent = me.parent
            } while (me.children.length > 10)
            me.parent.maybeSpill()
        },

        iterN: function (at, n, op) {
            for (var i = 0; i < this.children.length; ++i) {
                var child = this.children[i],
                    sz = child.chunkSize()
                if (at < sz) {
                    var used = Math.min(n, sz - at)
                    if (child.iterN(at, used, op)) {
                        return true
                    }
                    if ((n -= used) == 0) {
                        break
                    }
                    at = 0
                } else {
                    at -= sz
                }
            }
        },
    }

    // Line widgets are block elements displayed above or below a line.

    var LineWidget = function (doc, node, options) {
        if (options) {
            for (var opt in options) {
                if (options.hasOwnProperty(opt)) {
                    this[opt] = options[opt]
                }
            }
        }
        this.doc = doc
        this.node = node
    }

    LineWidget.prototype.clear = function () {
        var cm = this.doc.cm,
            ws = this.line.widgets,
            line = this.line,
            no = lineNo(line)
        if (no == null || !ws) {
            return
        }
        for (var i = 0; i < ws.length; ++i) {
            if (ws[i] == this) {
                ws.splice(i--, 1)
            }
        }
        if (!ws.length) {
            line.widgets = null
        }
        var height = widgetHeight(this)
        updateLineHeight(line, Math.max(0, line.height - height))
        if (cm) {
            runInOp(cm, function () {
                adjustScrollWhenAboveVisible(cm, line, -height)
                regLineChange(cm, no, 'widget')
            })
            signalLater(cm, 'lineWidgetCleared', cm, this, no)
        }
    }

    LineWidget.prototype.changed = function () {
        var this$1 = this

        var oldH = this.height,
            cm = this.doc.cm,
            line = this.line
        this.height = null
        var diff = widgetHeight(this) - oldH
        if (!diff) {
            return
        }
        if (!lineIsHidden(this.doc, line)) {
            updateLineHeight(line, line.height + diff)
        }
        if (cm) {
            runInOp(cm, function () {
                cm.curOp.forceUpdate = true
                adjustScrollWhenAboveVisible(cm, line, diff)
                signalLater(cm, 'lineWidgetChanged', cm, this$1, lineNo(line))
            })
        }
    }
    eventMixin(LineWidget)

    function adjustScrollWhenAboveVisible(cm, line, diff) {
        if (heightAtLine(line) < ((cm.curOp && cm.curOp.scrollTop) || cm.doc.scrollTop)) {
            addToScrollTop(cm, diff)
        }
    }

    function addLineWidget(doc, handle, node, options) {
        var widget = new LineWidget(doc, node, options)
        var cm = doc.cm
        if (cm && widget.noHScroll) {
            cm.display.alignWidgets = true
        }
        changeLine(doc, handle, 'widget', function (line) {
            var widgets = line.widgets || (line.widgets = [])
            if (widget.insertAt == null) {
                widgets.push(widget)
            } else {
                widgets.splice(Math.min(widgets.length, Math.max(0, widget.insertAt)), 0, widget)
            }
            widget.line = line
            if (cm && !lineIsHidden(doc, line)) {
                var aboveVisible = heightAtLine(line) < doc.scrollTop
                updateLineHeight(line, line.height + widgetHeight(widget))
                if (aboveVisible) {
                    addToScrollTop(cm, widget.height)
                }
                cm.curOp.forceUpdate = true
            }
            return true
        })
        if (cm) {
            signalLater(cm, 'lineWidgetAdded', cm, widget, typeof handle == 'number' ? handle : lineNo(handle))
        }
        return widget
    }

    // TEXTMARKERS

    // Created with markText and setBookmark methods. A TextMarker is a
    // handle that can be used to clear or find a marked position in the
    // document. Line objects hold arrays (markedSpans) containing
    // {from, to, marker} object pointing to such marker objects, and
    // indicating that such a marker is present on that line. Multiple
    // lines may point to the same marker when it spans across lines.
    // The spans will have null for their from/to properties when the
    // marker continues beyond the start/end of the line. Markers have
    // links back to the lines they currently touch.

    // Collapsed markers have unique ids, in order to be able to order
    // them, which is needed for uniquely determining an outer marker
    // when they overlap (they may nest, but not partially overlap).
    var nextMarkerId = 0

    var TextMarker = function (doc, type) {
        this.lines = []
        this.type = type
        this.doc = doc
        this.id = ++nextMarkerId
    }

    // Clear the marker.
    TextMarker.prototype.clear = function () {
        if (this.explicitlyCleared) {
            return
        }
        var cm = this.doc.cm,
            withOp = cm && !cm.curOp
        if (withOp) {
            startOperation(cm)
        }
        if (hasHandler(this, 'clear')) {
            var found = this.find()
            if (found) {
                signalLater(this, 'clear', found.from, found.to)
            }
        }
        var min = null,
            max = null
        for (var i = 0; i < this.lines.length; ++i) {
            var line = this.lines[i]
            var span = getMarkedSpanFor(line.markedSpans, this)
            if (cm && !this.collapsed) {
                regLineChange(cm, lineNo(line), 'text')
            } else if (cm) {
                if (span.to != null) {
                    max = lineNo(line)
                }
                if (span.from != null) {
                    min = lineNo(line)
                }
            }
            line.markedSpans = removeMarkedSpan(line.markedSpans, span)
            if (span.from == null && this.collapsed && !lineIsHidden(this.doc, line) && cm) {
                updateLineHeight(line, textHeight(cm.display))
            }
        }
        if (cm && this.collapsed && !cm.options.lineWrapping) {
            for (var i$1 = 0; i$1 < this.lines.length; ++i$1) {
                var visual = visualLine(this.lines[i$1]),
                    len = lineLength(visual)
                if (len > cm.display.maxLineLength) {
                    cm.display.maxLine = visual
                    cm.display.maxLineLength = len
                    cm.display.maxLineChanged = true
                }
            }
        }

        if (min != null && cm && this.collapsed) {
            regChange(cm, min, max + 1)
        }
        this.lines.length = 0
        this.explicitlyCleared = true
        if (this.atomic && this.doc.cantEdit) {
            this.doc.cantEdit = false
            if (cm) {
                reCheckSelection(cm.doc)
            }
        }
        if (cm) {
            signalLater(cm, 'markerCleared', cm, this, min, max)
        }
        if (withOp) {
            endOperation(cm)
        }
        if (this.parent) {
            this.parent.clear()
        }
    }

    // Find the position of the marker in the document. Returns a {from,
    // to} object by default. Side can be passed to get a specific side
    // -- 0 (both), -1 (left), or 1 (right). When lineObj is true, the
    // Pos objects returned contain a line object, rather than a line
    // number (used to prevent looking up the same line twice).
    TextMarker.prototype.find = function (side, lineObj) {
        if (side == null && this.type == 'bookmark') {
            side = 1
        }
        var from, to
        for (var i = 0; i < this.lines.length; ++i) {
            var line = this.lines[i]
            var span = getMarkedSpanFor(line.markedSpans, this)
            if (span.from != null) {
                from = Pos(lineObj ? line : lineNo(line), span.from)
                if (side == -1) {
                    return from
                }
            }
            if (span.to != null) {
                to = Pos(lineObj ? line : lineNo(line), span.to)
                if (side == 1) {
                    return to
                }
            }
        }
        return from && { from: from, to: to }
    }

    // Signals that the marker's widget changed, and surrounding layout
    // should be recomputed.
    TextMarker.prototype.changed = function () {
        var this$1 = this

        var pos = this.find(-1, true),
            widget = this,
            cm = this.doc.cm
        if (!pos || !cm) {
            return
        }
        runInOp(cm, function () {
            var line = pos.line,
                lineN = lineNo(pos.line)
            var view = findViewForLine(cm, lineN)
            if (view) {
                clearLineMeasurementCacheFor(view)
                cm.curOp.selectionChanged = cm.curOp.forceUpdate = true
            }
            cm.curOp.updateMaxLine = true
            if (!lineIsHidden(widget.doc, line) && widget.height != null) {
                var oldHeight = widget.height
                widget.height = null
                var dHeight = widgetHeight(widget) - oldHeight
                if (dHeight) {
                    updateLineHeight(line, line.height + dHeight)
                }
            }
            signalLater(cm, 'markerChanged', cm, this$1)
        })
    }

    TextMarker.prototype.attachLine = function (line) {
        if (!this.lines.length && this.doc.cm) {
            var op = this.doc.cm.curOp
            if (!op.maybeHiddenMarkers || indexOf(op.maybeHiddenMarkers, this) == -1) {
                ;(op.maybeUnhiddenMarkers || (op.maybeUnhiddenMarkers = [])).push(this)
            }
        }
        this.lines.push(line)
    }

    TextMarker.prototype.detachLine = function (line) {
        this.lines.splice(indexOf(this.lines, line), 1)
        if (!this.lines.length && this.doc.cm) {
            var op = this.doc.cm.curOp
            ;(op.maybeHiddenMarkers || (op.maybeHiddenMarkers = [])).push(this)
        }
    }
    eventMixin(TextMarker)

    // Create a marker, wire it up to the right lines, and
    function markText(doc, from, to, options, type) {
        // Shared markers (across linked documents) are handled separately
        // (markTextShared will call out to this again, once per
        // document).
        if (options && options.shared) {
            return markTextShared(doc, from, to, options, type)
        }
        // Ensure we are in an operation.
        if (doc.cm && !doc.cm.curOp) {
            return operation(doc.cm, markText)(doc, from, to, options, type)
        }

        var marker = new TextMarker(doc, type),
            diff = cmp(from, to)
        if (options) {
            copyObj(options, marker, false)
        }
        // Don't connect empty markers unless clearWhenEmpty is false
        if (diff > 0 || (diff == 0 && marker.clearWhenEmpty !== false)) {
            return marker
        }
        if (marker.replacedWith) {
            // Showing up as a widget implies collapsed (widget replaces text)
            marker.collapsed = true
            marker.widgetNode = eltP('span', [marker.replacedWith], 'CodeMirror-widget')
            if (!options.handleMouseEvents) {
                marker.widgetNode.setAttribute('cm-ignore-events', 'true')
            }
            if (options.insertLeft) {
                marker.widgetNode.insertLeft = true
            }
        }
        if (marker.collapsed) {
            if (conflictingCollapsedRange(doc, from.line, from, to, marker) || (from.line != to.line && conflictingCollapsedRange(doc, to.line, from, to, marker))) {
                throw new Error('Inserting collapsed marker partially overlapping an existing one')
            }
            seeCollapsedSpans()
        }

        if (marker.addToHistory) {
            addChangeToHistory(doc, { from: from, to: to, origin: 'markText' }, doc.sel, NaN)
        }

        var curLine = from.line,
            cm = doc.cm,
            updateMaxLine
        doc.iter(curLine, to.line + 1, function (line) {
            if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(line) == cm.display.maxLine) {
                updateMaxLine = true
            }
            if (marker.collapsed && curLine != from.line) {
                updateLineHeight(line, 0)
            }
            addMarkedSpan(line, new MarkedSpan(marker, curLine == from.line ? from.ch : null, curLine == to.line ? to.ch : null), doc.cm && doc.cm.curOp)
            ++curLine
        })
        // lineIsHidden depends on the presence of the spans, so needs a second pass
        if (marker.collapsed) {
            doc.iter(from.line, to.line + 1, function (line) {
                if (lineIsHidden(doc, line)) {
                    updateLineHeight(line, 0)
                }
            })
        }

        if (marker.clearOnEnter) {
            on(marker, 'beforeCursorEnter', function () {
                return marker.clear()
            })
        }

        if (marker.readOnly) {
            seeReadOnlySpans()
            if (doc.history.done.length || doc.history.undone.length) {
                doc.clearHistory()
            }
        }
        if (marker.collapsed) {
            marker.id = ++nextMarkerId
            marker.atomic = true
        }
        if (cm) {
            // Sync editor state
            if (updateMaxLine) {
                cm.curOp.updateMaxLine = true
            }
            if (marker.collapsed) {
                regChange(cm, from.line, to.line + 1)
            } else if (marker.className || marker.startStyle || marker.endStyle || marker.css || marker.attributes || marker.title) {
                for (var i = from.line; i <= to.line; i++) {
                    regLineChange(cm, i, 'text')
                }
            }
            if (marker.atomic) {
                reCheckSelection(cm.doc)
            }
            signalLater(cm, 'markerAdded', cm, marker)
        }
        return marker
    }

    // SHARED TEXTMARKERS

    // A shared marker spans multiple linked documents. It is
    // implemented as a meta-marker-object controlling multiple normal
    // markers.
    var SharedTextMarker = function (markers, primary) {
        this.markers = markers
        this.primary = primary
        for (var i = 0; i < markers.length; ++i) {
            markers[i].parent = this
        }
    }

    SharedTextMarker.prototype.clear = function () {
        if (this.explicitlyCleared) {
            return
        }
        this.explicitlyCleared = true
        for (var i = 0; i < this.markers.length; ++i) {
            this.markers[i].clear()
        }
        signalLater(this, 'clear')
    }

    SharedTextMarker.prototype.find = function (side, lineObj) {
        return this.primary.find(side, lineObj)
    }
    eventMixin(SharedTextMarker)

    function markTextShared(doc, from, to, options, type) {
        options = copyObj(options)
        options.shared = false
        var markers = [markText(doc, from, to, options, type)],
            primary = markers[0]
        var widget = options.widgetNode
        linkedDocs(doc, function (doc) {
            if (widget) {
                options.widgetNode = widget.cloneNode(true)
            }
            markers.push(markText(doc, clipPos(doc, from), clipPos(doc, to), options, type))
            for (var i = 0; i < doc.linked.length; ++i) {
                if (doc.linked[i].isParent) {
                    return
                }
            }
            primary = lst(markers)
        })
        return new SharedTextMarker(markers, primary)
    }

    function findSharedMarkers(doc) {
        return doc.findMarks(Pos(doc.first, 0), doc.clipPos(Pos(doc.lastLine())), function (m) {
            return m.parent
        })
    }

    function copySharedMarkers(doc, markers) {
        for (var i = 0; i < markers.length; i++) {
            var marker = markers[i],
                pos = marker.find()
            var mFrom = doc.clipPos(pos.from),
                mTo = doc.clipPos(pos.to)
            if (cmp(mFrom, mTo)) {
                var subMark = markText(doc, mFrom, mTo, marker.primary, marker.primary.type)
                marker.markers.push(subMark)
                subMark.parent = marker
            }
        }
    }

    function detachSharedMarkers(markers) {
        var loop = function (i) {
            var marker = markers[i],
                linked = [marker.primary.doc]
            linkedDocs(marker.primary.doc, function (d) {
                return linked.push(d)
            })
            for (var j = 0; j < marker.markers.length; j++) {
                var subMarker = marker.markers[j]
                if (indexOf(linked, subMarker.doc) == -1) {
                    subMarker.parent = null
                    marker.markers.splice(j--, 1)
                }
            }
        }

        for (var i = 0; i < markers.length; i++) loop(i)
    }

    var nextDocId = 0
    var Doc = function (text, mode, firstLine, lineSep, direction) {
        if (!(this instanceof Doc)) {
            return new Doc(text, mode, firstLine, lineSep, direction)
        }
        if (firstLine == null) {
            firstLine = 0
        }

        BranchChunk.call(this, [new LeafChunk([new Line('', null)])])
        this.first = firstLine
        this.scrollTop = this.scrollLeft = 0
        this.cantEdit = false
        this.cleanGeneration = 1
        this.modeFrontier = this.highlightFrontier = firstLine
        var start = Pos(firstLine, 0)
        this.sel = simpleSelection(start)
        this.history = new History(null)
        this.id = ++nextDocId
        this.modeOption = mode
        this.lineSep = lineSep
        this.direction = direction == 'rtl' ? 'rtl' : 'ltr'
        this.extend = false

        if (typeof text == 'string') {
            text = this.splitLines(text)
        }
        updateDoc(this, { from: start, to: start, text: text })
        setSelection(this, simpleSelection(start), sel_dontScroll)
    }

    Doc.prototype = createObj(BranchChunk.prototype, {
        constructor: Doc,
        // Iterate over the document. Supports two forms -- with only one
        // argument, it calls that for each line in the document. With
        // three, it iterates over the range given by the first two (with
        // the second being non-inclusive).
        iter: function (from, to, op) {
            if (op) {
                this.iterN(from - this.first, to - from, op)
            } else {
                this.iterN(this.first, this.first + this.size, from)
            }
        },

        // Non-public interface for adding and removing lines.
        insert: function (at, lines) {
            var height = 0
            for (var i = 0; i < lines.length; ++i) {
                height += lines[i].height
            }
            this.insertInner(at - this.first, lines, height)
        },
        remove: function (at, n) {
            this.removeInner(at - this.first, n)
        },

        // From here, the methods are part of the public interface. Most
        // are also available from CodeMirror (editor) instances.

        getValue: function (lineSep) {
            var lines = getLines(this, this.first, this.first + this.size)
            if (lineSep === false) {
                return lines
            }
            return lines.join(lineSep || this.lineSeparator())
        },
        setValue: docMethodOp(function (code) {
            var top = Pos(this.first, 0),
                last = this.first + this.size - 1
            makeChange(this, { from: top, to: Pos(last, getLine(this, last).text.length), text: this.splitLines(code), origin: 'setValue', full: true }, true)
            if (this.cm) {
                scrollToCoords(this.cm, 0, 0)
            }
            setSelection(this, simpleSelection(top), sel_dontScroll)
        }),
        replaceRange: function (code, from, to, origin) {
            from = clipPos(this, from)
            to = to ? clipPos(this, to) : from
            replaceRange(this, code, from, to, origin)
        },
        getRange: function (from, to, lineSep) {
            var lines = getBetween(this, clipPos(this, from), clipPos(this, to))
            if (lineSep === false) {
                return lines
            }
            if (lineSep === '') {
                return lines.join('')
            }
            return lines.join(lineSep || this.lineSeparator())
        },

        getLine: function (line) {
            var l = this.getLineHandle(line)
            return l && l.text
        },

        getLineHandle: function (line) {
            if (isLine(this, line)) {
                return getLine(this, line)
            }
        },
        getLineNumber: function (line) {
            return lineNo(line)
        },

        getLineHandleVisualStart: function (line) {
            if (typeof line == 'number') {
                line = getLine(this, line)
            }
            return visualLine(line)
        },

        lineCount: function () {
            return this.size
        },
        firstLine: function () {
            return this.first
        },
        lastLine: function () {
            return this.first + this.size - 1
        },

        clipPos: function (pos) {
            return clipPos(this, pos)
        },

        getCursor: function (start) {
            var range = this.sel.primary(),
                pos
            if (start == null || start == 'head') {
                pos = range.head
            } else if (start == 'anchor') {
                pos = range.anchor
            } else if (start == 'end' || start == 'to' || start === false) {
                pos = range.to()
            } else {
                pos = range.from()
            }
            return pos
        },
        listSelections: function () {
            return this.sel.ranges
        },
        somethingSelected: function () {
            return this.sel.somethingSelected()
        },

        setCursor: docMethodOp(function (line, ch, options) {
            setSimpleSelection(this, clipPos(this, typeof line == 'number' ? Pos(line, ch || 0) : line), null, options)
        }),
        setSelection: docMethodOp(function (anchor, head, options) {
            setSimpleSelection(this, clipPos(this, anchor), clipPos(this, head || anchor), options)
        }),
        extendSelection: docMethodOp(function (head, other, options) {
            extendSelection(this, clipPos(this, head), other && clipPos(this, other), options)
        }),
        extendSelections: docMethodOp(function (heads, options) {
            extendSelections(this, clipPosArray(this, heads), options)
        }),
        extendSelectionsBy: docMethodOp(function (f, options) {
            var heads = map(this.sel.ranges, f)
            extendSelections(this, clipPosArray(this, heads), options)
        }),
        setSelections: docMethodOp(function (ranges, primary, options) {
            if (!ranges.length) {
                return
            }
            var out = []
            for (var i = 0; i < ranges.length; i++) {
                out[i] = new Range(clipPos(this, ranges[i].anchor), clipPos(this, ranges[i].head || ranges[i].anchor))
            }
            if (primary == null) {
                primary = Math.min(ranges.length - 1, this.sel.primIndex)
            }
            setSelection(this, normalizeSelection(this.cm, out, primary), options)
        }),
        addSelection: docMethodOp(function (anchor, head, options) {
            var ranges = this.sel.ranges.slice(0)
            ranges.push(new Range(clipPos(this, anchor), clipPos(this, head || anchor)))
            setSelection(this, normalizeSelection(this.cm, ranges, ranges.length - 1), options)
        }),

        getSelection: function (lineSep) {
            var ranges = this.sel.ranges,
                lines
            for (var i = 0; i < ranges.length; i++) {
                var sel = getBetween(this, ranges[i].from(), ranges[i].to())
                lines = lines ? lines.concat(sel) : sel
            }
            if (lineSep === false) {
                return lines
            } else {
                return lines.join(lineSep || this.lineSeparator())
            }
        },
        getSelections: function (lineSep) {
            var parts = [],
                ranges = this.sel.ranges
            for (var i = 0; i < ranges.length; i++) {
                var sel = getBetween(this, ranges[i].from(), ranges[i].to())
                if (lineSep !== false) {
                    sel = sel.join(lineSep || this.lineSeparator())
                }
                parts[i] = sel
            }
            return parts
        },
        replaceSelection: function (code, collapse, origin) {
            var dup = []
            for (var i = 0; i < this.sel.ranges.length; i++) {
                dup[i] = code
            }
            this.replaceSelections(dup, collapse, origin || '+input')
        },
        replaceSelections: docMethodOp(function (code, collapse, origin) {
            var changes = [],
                sel = this.sel
            for (var i = 0; i < sel.ranges.length; i++) {
                var range = sel.ranges[i]
                changes[i] = { from: range.from(), to: range.to(), text: this.splitLines(code[i]), origin: origin }
            }
            var newSel = collapse && collapse != 'end' && computeReplacedSel(this, changes, collapse)
            for (var i$1 = changes.length - 1; i$1 >= 0; i$1--) {
                makeChange(this, changes[i$1])
            }
            if (newSel) {
                setSelectionReplaceHistory(this, newSel)
            } else if (this.cm) {
                ensureCursorVisible(this.cm)
            }
        }),
        undo: docMethodOp(function () {
            makeChangeFromHistory(this, 'undo')
        }),
        redo: docMethodOp(function () {
            makeChangeFromHistory(this, 'redo')
        }),
        undoSelection: docMethodOp(function () {
            makeChangeFromHistory(this, 'undo', true)
        }),
        redoSelection: docMethodOp(function () {
            makeChangeFromHistory(this, 'redo', true)
        }),

        setExtending: function (val) {
            this.extend = val
        },
        getExtending: function () {
            return this.extend
        },

        historySize: function () {
            var hist = this.history,
                done = 0,
                undone = 0
            for (var i = 0; i < hist.done.length; i++) {
                if (!hist.done[i].ranges) {
                    ++done
                }
            }
            for (var i$1 = 0; i$1 < hist.undone.length; i$1++) {
                if (!hist.undone[i$1].ranges) {
                    ++undone
                }
            }
            return { undo: done, redo: undone }
        },
        clearHistory: function () {
            var this$1 = this

            this.history = new History(this.history)
            linkedDocs(
                this,
                function (doc) {
                    return (doc.history = this$1.history)
                },
                true
            )
        },

        markClean: function () {
            this.cleanGeneration = this.changeGeneration(true)
        },
        changeGeneration: function (forceSplit) {
            if (forceSplit) {
                this.history.lastOp = this.history.lastSelOp = this.history.lastOrigin = null
            }
            return this.history.generation
        },
        isClean: function (gen) {
            return this.history.generation == (gen || this.cleanGeneration)
        },

        getHistory: function () {
            return { done: copyHistoryArray(this.history.done), undone: copyHistoryArray(this.history.undone) }
        },
        setHistory: function (histData) {
            var hist = (this.history = new History(this.history))
            hist.done = copyHistoryArray(histData.done.slice(0), null, true)
            hist.undone = copyHistoryArray(histData.undone.slice(0), null, true)
        },

        setGutterMarker: docMethodOp(function (line, gutterID, value) {
            return changeLine(this, line, 'gutter', function (line) {
                var markers = line.gutterMarkers || (line.gutterMarkers = {})
                markers[gutterID] = value
                if (!value && isEmpty(markers)) {
                    line.gutterMarkers = null
                }
                return true
            })
        }),

        clearGutter: docMethodOp(function (gutterID) {
            var this$1 = this

            this.iter(function (line) {
                if (line.gutterMarkers && line.gutterMarkers[gutterID]) {
                    changeLine(this$1, line, 'gutter', function () {
                        line.gutterMarkers[gutterID] = null
                        if (isEmpty(line.gutterMarkers)) {
                            line.gutterMarkers = null
                        }
                        return true
                    })
                }
            })
        }),

        lineInfo: function (line) {
            var n
            if (typeof line == 'number') {
                if (!isLine(this, line)) {
                    return null
                }
                n = line
                line = getLine(this, line)
                if (!line) {
                    return null
                }
            } else {
                n = lineNo(line)
                if (n == null) {
                    return null
                }
            }
            return { line: n, handle: line, text: line.text, gutterMarkers: line.gutterMarkers, textClass: line.textClass, bgClass: line.bgClass, wrapClass: line.wrapClass, widgets: line.widgets }
        },

        addLineClass: docMethodOp(function (handle, where, cls) {
            return changeLine(this, handle, where == 'gutter' ? 'gutter' : 'class', function (line) {
                var prop = where == 'text' ? 'textClass' : where == 'background' ? 'bgClass' : where == 'gutter' ? 'gutterClass' : 'wrapClass'
                if (!line[prop]) {
                    line[prop] = cls
                } else if (classTest(cls).test(line[prop])) {
                    return false
                } else {
                    line[prop] += ' ' + cls
                }
                return true
            })
        }),
        removeLineClass: docMethodOp(function (handle, where, cls) {
            return changeLine(this, handle, where == 'gutter' ? 'gutter' : 'class', function (line) {
                var prop = where == 'text' ? 'textClass' : where == 'background' ? 'bgClass' : where == 'gutter' ? 'gutterClass' : 'wrapClass'
                var cur = line[prop]
                if (!cur) {
                    return false
                } else if (cls == null) {
                    line[prop] = null
                } else {
                    var found = cur.match(classTest(cls))
                    if (!found) {
                        return false
                    }
                    var end = found.index + found[0].length
                    line[prop] = cur.slice(0, found.index) + (!found.index || end == cur.length ? '' : ' ') + cur.slice(end) || null
                }
                return true
            })
        }),

        addLineWidget: docMethodOp(function (handle, node, options) {
            return addLineWidget(this, handle, node, options)
        }),
        removeLineWidget: function (widget) {
            widget.clear()
        },

        markText: function (from, to, options) {
            return markText(this, clipPos(this, from), clipPos(this, to), options, (options && options.type) || 'range')
        },
        setBookmark: function (pos, options) {
            var realOpts = {
                replacedWith: options && (options.nodeType == null ? options.widget : options),
                insertLeft: options && options.insertLeft,
                clearWhenEmpty: false,
                shared: options && options.shared,
                handleMouseEvents: options && options.handleMouseEvents,
            }
            pos = clipPos(this, pos)
            return markText(this, pos, pos, realOpts, 'bookmark')
        },
        findMarksAt: function (pos) {
            pos = clipPos(this, pos)
            var markers = [],
                spans = getLine(this, pos.line).markedSpans
            if (spans) {
                for (var i = 0; i < spans.length; ++i) {
                    var span = spans[i]
                    if ((span.from == null || span.from <= pos.ch) && (span.to == null || span.to >= pos.ch)) {
                        markers.push(span.marker.parent || span.marker)
                    }
                }
            }
            return markers
        },
        findMarks: function (from, to, filter) {
            from = clipPos(this, from)
            to = clipPos(this, to)
            var found = [],
                lineNo = from.line
            this.iter(from.line, to.line + 1, function (line) {
                var spans = line.markedSpans
                if (spans) {
                    for (var i = 0; i < spans.length; i++) {
                        var span = spans[i]
                        if (
                            !(
                                (span.to != null && lineNo == from.line && from.ch >= span.to) ||
                                (span.from == null && lineNo != from.line) ||
                                (span.from != null && lineNo == to.line && span.from >= to.ch)
                            ) &&
                            (!filter || filter(span.marker))
                        ) {
                            found.push(span.marker.parent || span.marker)
                        }
                    }
                }
                ++lineNo
            })
            return found
        },
        getAllMarks: function () {
            var markers = []
            this.iter(function (line) {
                var sps = line.markedSpans
                if (sps) {
                    for (var i = 0; i < sps.length; ++i) {
                        if (sps[i].from != null) {
                            markers.push(sps[i].marker)
                        }
                    }
                }
            })
            return markers
        },

        posFromIndex: function (off) {
            var ch,
                lineNo = this.first,
                sepSize = this.lineSeparator().length
            this.iter(function (line) {
                var sz = line.text.length + sepSize
                if (sz > off) {
                    ch = off
                    return true
                }
                off -= sz
                ++lineNo
            })
            return clipPos(this, Pos(lineNo, ch))
        },
        indexFromPos: function (coords) {
            coords = clipPos(this, coords)
            var index = coords.ch
            if (coords.line < this.first || coords.ch < 0) {
                return 0
            }
            var sepSize = this.lineSeparator().length
            this.iter(this.first, coords.line, function (line) {
                // iter aborts when callback returns a truthy value
                index += line.text.length + sepSize
            })
            return index
        },

        copy: function (copyHistory) {
            var doc = new Doc(getLines(this, this.first, this.first + this.size), this.modeOption, this.first, this.lineSep, this.direction)
            doc.scrollTop = this.scrollTop
            doc.scrollLeft = this.scrollLeft
            doc.sel = this.sel
            doc.extend = false
            if (copyHistory) {
                doc.history.undoDepth = this.history.undoDepth
                doc.setHistory(this.getHistory())
            }
            return doc
        },

        linkedDoc: function (options) {
            if (!options) {
                options = {}
            }
            var from = this.first,
                to = this.first + this.size
            if (options.from != null && options.from > from) {
                from = options.from
            }
            if (options.to != null && options.to < to) {
                to = options.to
            }
            var copy = new Doc(getLines(this, from, to), options.mode || this.modeOption, from, this.lineSep, this.direction)
            if (options.sharedHist) {
                copy.history = this.history
            }
            ;(this.linked || (this.linked = [])).push({ doc: copy, sharedHist: options.sharedHist })
            copy.linked = [{ doc: this, isParent: true, sharedHist: options.sharedHist }]
            copySharedMarkers(copy, findSharedMarkers(this))
            return copy
        },
        unlinkDoc: function (other) {
            if (other instanceof CodeMirror) {
                other = other.doc
            }
            if (this.linked) {
                for (var i = 0; i < this.linked.length; ++i) {
                    var link = this.linked[i]
                    if (link.doc != other) {
                        continue
                    }
                    this.linked.splice(i, 1)
                    other.unlinkDoc(this)
                    detachSharedMarkers(findSharedMarkers(this))
                    break
                }
            }
            // If the histories were shared, split them again
            if (other.history == this.history) {
                var splitIds = [other.id]
                linkedDocs(
                    other,
                    function (doc) {
                        return splitIds.push(doc.id)
                    },
                    true
                )
                other.history = new History(null)
                other.history.done = copyHistoryArray(this.history.done, splitIds)
                other.history.undone = copyHistoryArray(this.history.undone, splitIds)
            }
        },
        iterLinkedDocs: function (f) {
            linkedDocs(this, f)
        },

        getMode: function () {
            return this.mode
        },
        getEditor: function () {
            return this.cm
        },

        splitLines: function (str) {
            if (this.lineSep) {
                return str.split(this.lineSep)
            }
            return splitLinesAuto(str)
        },
        lineSeparator: function () {
            return this.lineSep || '\n'
        },

        setDirection: docMethodOp(function (dir) {
            if (dir != 'rtl') {
                dir = 'ltr'
            }
            if (dir == this.direction) {
                return
            }
            this.direction = dir
            this.iter(function (line) {
                return (line.order = null)
            })
            if (this.cm) {
                directionChanged(this.cm)
            }
        }),
    })

    // Public alias.
    Doc.prototype.eachLine = Doc.prototype.iter

    // Kludge to work around strange IE behavior where it'll sometimes
    // re-fire a series of drag-related events right after the drop (#1551)
    var lastDrop = 0

    function onDrop(e) {
        var cm = this
        clearDragCursor(cm)
        if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) {
            return
        }
        e_preventDefault(e)
        if (ie) {
            lastDrop = +new Date()
        }
        var pos = posFromMouse(cm, e, true),
            files = e.dataTransfer.files
        if (!pos || cm.isReadOnly()) {
            return
        }
        // Might be a file drop, in which case we simply extract the text
        // and insert it.
        if (files && files.length && window.FileReader && window.File) {
            var n = files.length,
                text = Array(n),
                read = 0
            var markAsReadAndPasteIfAllFilesAreRead = function () {
                if (++read == n) {
                    operation(cm, function () {
                        pos = clipPos(cm.doc, pos)
                        var change = {
                            from: pos,
                            to: pos,
                            text: cm.doc.splitLines(
                                text
                                    .filter(function (t) {
                                        return t != null
                                    })
                                    .join(cm.doc.lineSeparator())
                            ),
                            origin: 'paste',
                        }
                        makeChange(cm.doc, change)
                        setSelectionReplaceHistory(cm.doc, simpleSelection(clipPos(cm.doc, pos), clipPos(cm.doc, changeEnd(change))))
                    })()
                }
            }
            var readTextFromFile = function (file, i) {
                if (cm.options.allowDropFileTypes && indexOf(cm.options.allowDropFileTypes, file.type) == -1) {
                    markAsReadAndPasteIfAllFilesAreRead()
                    return
                }
                var reader = new FileReader()
                reader.onerror = function () {
                    return markAsReadAndPasteIfAllFilesAreRead()
                }
                reader.onload = function () {
                    var content = reader.result
                    if (/[\x00-\x08\x0e-\x1f]{2}/.test(content)) {
                        markAsReadAndPasteIfAllFilesAreRead()
                        return
                    }
                    text[i] = content
                    markAsReadAndPasteIfAllFilesAreRead()
                }
                reader.readAsText(file)
            }
            for (var i = 0; i < files.length; i++) {
                readTextFromFile(files[i], i)
            }
        } else {
            // Normal drop
            // Don't do a replace if the drop happened inside of the selected text.
            if (cm.state.draggingText && cm.doc.sel.contains(pos) > -1) {
                cm.state.draggingText(e)
                // Ensure the editor is re-focused
                setTimeout(function () {
                    return cm.display.input.focus()
                }, 20)
                return
            }
            try {
                var text$1 = e.dataTransfer.getData('Text')
                if (text$1) {
                    var selected
                    if (cm.state.draggingText && !cm.state.draggingText.copy) {
                        selected = cm.listSelections()
                    }
                    setSelectionNoUndo(cm.doc, simpleSelection(pos, pos))
                    if (selected) {
                        for (var i$1 = 0; i$1 < selected.length; ++i$1) {
                            replaceRange(cm.doc, '', selected[i$1].anchor, selected[i$1].head, 'drag')
                        }
                    }
                    cm.replaceSelection(text$1, 'around', 'paste')
                    cm.display.input.focus()
                }
            } catch (e$1) {}
        }
    }

    function onDragStart(cm, e) {
        if (ie && (!cm.state.draggingText || +new Date() - lastDrop < 100)) {
            e_stop(e)
            return
        }
        if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) {
            return
        }

        e.dataTransfer.setData('Text', cm.getSelection())
        e.dataTransfer.effectAllowed = 'copyMove'

        // Use dummy image instead of default browsers image.
        // Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.
        if (e.dataTransfer.setDragImage && !safari) {
            var img = elt('img', null, null, 'position: fixed; left: 0; top: 0;')
            img.src = 'data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw=='
            if (presto) {
                img.width = img.height = 1
                cm.display.wrapper.appendChild(img)
                // Force a relayout, or Opera won't use our image for some obscure reason
                img._top = img.offsetTop
            }
            e.dataTransfer.setDragImage(img, 0, 0)
            if (presto) {
                img.parentNode.removeChild(img)
            }
        }
    }

    function onDragOver(cm, e) {
        var pos = posFromMouse(cm, e)
        if (!pos) {
            return
        }
        var frag = document.createDocumentFragment()
        drawSelectionCursor(cm, pos, frag)
        if (!cm.display.dragCursor) {
            cm.display.dragCursor = elt('div', null, 'CodeMirror-cursors CodeMirror-dragcursors')
            cm.display.lineSpace.insertBefore(cm.display.dragCursor, cm.display.cursorDiv)
        }
        removeChildrenAndAdd(cm.display.dragCursor, frag)
    }

    function clearDragCursor(cm) {
        if (cm.display.dragCursor) {
            cm.display.lineSpace.removeChild(cm.display.dragCursor)
            cm.display.dragCursor = null
        }
    }

    // These must be handled carefully, because naively registering a
    // handler for each editor will cause the editors to never be
    // garbage collected.

    function forEachCodeMirror(f) {
        if (!document.getElementsByClassName) {
            return
        }
        var byClass = document.getElementsByClassName('CodeMirror'),
            editors = []
        for (var i = 0; i < byClass.length; i++) {
            var cm = byClass[i].CodeMirror
            if (cm) {
                editors.push(cm)
            }
        }
        if (editors.length) {
            editors[0].operation(function () {
                for (var i = 0; i < editors.length; i++) {
                    f(editors[i])
                }
            })
        }
    }

    var globalsRegistered = false
    function ensureGlobalHandlers() {
        if (globalsRegistered) {
            return
        }
        registerGlobalHandlers()
        globalsRegistered = true
    }
    function registerGlobalHandlers() {
        // When the window resizes, we need to refresh active editors.
        var resizeTimer
        on(window, 'resize', function () {
            if (resizeTimer == null) {
                resizeTimer = setTimeout(function () {
                    resizeTimer = null
                    forEachCodeMirror(onResize)
                }, 100)
            }
        })
        // When the window loses focus, we want to show the editor as blurred
        on(window, 'blur', function () {
            return forEachCodeMirror(onBlur)
        })
    }
    // Called when the window resizes
    function onResize(cm) {
        var d = cm.display
        // Might be a text scaling operation, clear size caches.
        d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null
        d.scrollbarsClipped = false
        cm.setSize()
    }

    var keyNames = {
        3: 'Pause',
        8: 'Backspace',
        9: 'Tab',
        13: 'Enter',
        16: 'Shift',
        17: 'Ctrl',
        18: 'Alt',
        19: 'Pause',
        20: 'CapsLock',
        27: 'Esc',
        32: 'Space',
        33: 'PageUp',
        34: 'PageDown',
        35: 'End',
        36: 'Home',
        37: 'Left',
        38: 'Up',
        39: 'Right',
        40: 'Down',
        44: 'PrintScrn',
        45: 'Insert',
        46: 'Delete',
        59: ';',
        61: '=',
        91: 'Mod',
        92: 'Mod',
        93: 'Mod',
        106: '*',
        107: '=',
        109: '-',
        110: '.',
        111: '/',
        145: 'ScrollLock',
        173: '-',
        186: ';',
        187: '=',
        188: ',',
        189: '-',
        190: '.',
        191: '/',
        192: '`',
        219: '[',
        220: '\\',
        221: ']',
        222: "'",
        224: 'Mod',
        63232: 'Up',
        63233: 'Down',
        63234: 'Left',
        63235: 'Right',
        63272: 'Delete',
        63273: 'Home',
        63275: 'End',
        63276: 'PageUp',
        63277: 'PageDown',
        63302: 'Insert',
    }

    // Number keys
    for (var i = 0; i < 10; i++) {
        keyNames[i + 48] = keyNames[i + 96] = String(i)
    }
    // Alphabetic keys
    for (var i$1 = 65; i$1 <= 90; i$1++) {
        keyNames[i$1] = String.fromCharCode(i$1)
    }
    // Function keys
    for (var i$2 = 1; i$2 <= 12; i$2++) {
        keyNames[i$2 + 111] = keyNames[i$2 + 63235] = 'F' + i$2
    }

    var keyMap = {}

    keyMap.basic = {
        Left: 'goCharLeft',
        Right: 'goCharRight',
        Up: 'goLineUp',
        Down: 'goLineDown',
        End: 'goLineEnd',
        Home: 'goLineStartSmart',
        PageUp: 'goPageUp',
        PageDown: 'goPageDown',
        Delete: 'delCharAfter',
        Backspace: 'delCharBefore',
        'Shift-Backspace': 'delCharBefore',
        Tab: 'defaultTab',
        'Shift-Tab': 'indentAuto',
        Enter: 'newlineAndIndent',
        Insert: 'toggleOverwrite',
        Esc: 'singleSelection',
    }
    // Note that the save and find-related commands aren't defined by
    // default. User code or addons can define them. Unknown commands
    // are simply ignored.
    keyMap.pcDefault = {
        'Ctrl-A': 'selectAll',
        'Ctrl-D': 'deleteLine',
        'Ctrl-Z': 'undo',
        'Shift-Ctrl-Z': 'redo',
        'Ctrl-Y': 'redo',
        'Ctrl-Home': 'goDocStart',
        'Ctrl-End': 'goDocEnd',
        'Ctrl-Up': 'goLineUp',
        'Ctrl-Down': 'goLineDown',
        'Ctrl-Left': 'goGroupLeft',
        'Ctrl-Right': 'goGroupRight',
        'Alt-Left': 'goLineStart',
        'Alt-Right': 'goLineEnd',
        'Ctrl-Backspace': 'delGroupBefore',
        'Ctrl-Delete': 'delGroupAfter',
        'Ctrl-S': 'save',
        'Ctrl-F': 'find',
        'Ctrl-G': 'findNext',
        'Shift-Ctrl-G': 'findPrev',
        'Shift-Ctrl-F': 'replace',
        'Shift-Ctrl-R': 'replaceAll',
        'Ctrl-[': 'indentLess',
        'Ctrl-]': 'indentMore',
        'Ctrl-U': 'undoSelection',
        'Shift-Ctrl-U': 'redoSelection',
        'Alt-U': 'redoSelection',
        fallthrough: 'basic',
    }
    // Very basic readline/emacs-style bindings, which are standard on Mac.
    keyMap.emacsy = {
        'Ctrl-F': 'goCharRight',
        'Ctrl-B': 'goCharLeft',
        'Ctrl-P': 'goLineUp',
        'Ctrl-N': 'goLineDown',
        'Ctrl-A': 'goLineStart',
        'Ctrl-E': 'goLineEnd',
        'Ctrl-V': 'goPageDown',
        'Shift-Ctrl-V': 'goPageUp',
        'Ctrl-D': 'delCharAfter',
        'Ctrl-H': 'delCharBefore',
        'Alt-Backspace': 'delWordBefore',
        'Ctrl-K': 'killLine',
        'Ctrl-T': 'transposeChars',
        'Ctrl-O': 'openLine',
    }
    keyMap.macDefault = {
        'Cmd-A': 'selectAll',
        'Cmd-D': 'deleteLine',
        'Cmd-Z': 'undo',
        'Shift-Cmd-Z': 'redo',
        'Cmd-Y': 'redo',
        'Cmd-Home': 'goDocStart',
        'Cmd-Up': 'goDocStart',
        'Cmd-End': 'goDocEnd',
        'Cmd-Down': 'goDocEnd',
        'Alt-Left': 'goGroupLeft',
        'Alt-Right': 'goGroupRight',
        'Cmd-Left': 'goLineLeft',
        'Cmd-Right': 'goLineRight',
        'Alt-Backspace': 'delGroupBefore',
        'Ctrl-Alt-Backspace': 'delGroupAfter',
        'Alt-Delete': 'delGroupAfter',
        'Cmd-S': 'save',
        'Cmd-F': 'find',
        'Cmd-G': 'findNext',
        'Shift-Cmd-G': 'findPrev',
        'Cmd-Alt-F': 'replace',
        'Shift-Cmd-Alt-F': 'replaceAll',
        'Cmd-[': 'indentLess',
        'Cmd-]': 'indentMore',
        'Cmd-Backspace': 'delWrappedLineLeft',
        'Cmd-Delete': 'delWrappedLineRight',
        'Cmd-U': 'undoSelection',
        'Shift-Cmd-U': 'redoSelection',
        'Ctrl-Up': 'goDocStart',
        'Ctrl-Down': 'goDocEnd',
        fallthrough: ['basic', 'emacsy'],
    }
    keyMap['default'] = mac ? keyMap.macDefault : keyMap.pcDefault

    // KEYMAP DISPATCH

    function normalizeKeyName(name) {
        var parts = name.split(/-(?!$)/)
        name = parts[parts.length - 1]
        var alt, ctrl, shift, cmd
        for (var i = 0; i < parts.length - 1; i++) {
            var mod = parts[i]
            if (/^(cmd|meta|m)$/i.test(mod)) {
                cmd = true
            } else if (/^a(lt)?$/i.test(mod)) {
                alt = true
            } else if (/^(c|ctrl|control)$/i.test(mod)) {
                ctrl = true
            } else if (/^s(hift)?$/i.test(mod)) {
                shift = true
            } else {
                throw new Error('Unrecognized modifier name: ' + mod)
            }
        }
        if (alt) {
            name = 'Alt-' + name
        }
        if (ctrl) {
            name = 'Ctrl-' + name
        }
        if (cmd) {
            name = 'Cmd-' + name
        }
        if (shift) {
            name = 'Shift-' + name
        }
        return name
    }

    // This is a kludge to keep keymaps mostly working as raw objects
    // (backwards compatibility) while at the same time support features
    // like normalization and multi-stroke key bindings. It compiles a
    // new normalized keymap, and then updates the old object to reflect
    // this.
    function normalizeKeyMap(keymap) {
        var copy = {}
        for (var keyname in keymap) {
            if (keymap.hasOwnProperty(keyname)) {
                var value = keymap[keyname]
                if (/^(name|fallthrough|(de|at)tach)$/.test(keyname)) {
                    continue
                }
                if (value == '...') {
                    delete keymap[keyname]
                    continue
                }

                var keys = map(keyname.split(' '), normalizeKeyName)
                for (var i = 0; i < keys.length; i++) {
                    var val = void 0,
                        name = void 0
                    if (i == keys.length - 1) {
                        name = keys.join(' ')
                        val = value
                    } else {
                        name = keys.slice(0, i + 1).join(' ')
                        val = '...'
                    }
                    var prev = copy[name]
                    if (!prev) {
                        copy[name] = val
                    } else if (prev != val) {
                        throw new Error('Inconsistent bindings for ' + name)
                    }
                }
                delete keymap[keyname]
            }
        }
        for (var prop in copy) {
            keymap[prop] = copy[prop]
        }
        return keymap
    }

    function lookupKey(key, map, handle, context) {
        map = getKeyMap(map)
        var found = map.call ? map.call(key, context) : map[key]
        if (found === false) {
            return 'nothing'
        }
        if (found === '...') {
            return 'multi'
        }
        if (found != null && handle(found)) {
            return 'handled'
        }

        if (map.fallthrough) {
            if (Object.prototype.toString.call(map.fallthrough) != '[object Array]') {
                return lookupKey(key, map.fallthrough, handle, context)
            }
            for (var i = 0; i < map.fallthrough.length; i++) {
                var result = lookupKey(key, map.fallthrough[i], handle, context)
                if (result) {
                    return result
                }
            }
        }
    }

    // Modifier key presses don't count as 'real' key presses for the
    // purpose of keymap fallthrough.
    function isModifierKey(value) {
        var name = typeof value == 'string' ? value : keyNames[value.keyCode]
        return name == 'Ctrl' || name == 'Alt' || name == 'Shift' || name == 'Mod'
    }

    function addModifierNames(name, event, noShift) {
        var base = name
        if (event.altKey && base != 'Alt') {
            name = 'Alt-' + name
        }
        if ((flipCtrlCmd ? event.metaKey : event.ctrlKey) && base != 'Ctrl') {
            name = 'Ctrl-' + name
        }
        if ((flipCtrlCmd ? event.ctrlKey : event.metaKey) && base != 'Mod') {
            name = 'Cmd-' + name
        }
        if (!noShift && event.shiftKey && base != 'Shift') {
            name = 'Shift-' + name
        }
        return name
    }

    // Look up the name of a key as indicated by an event object.
    function keyName(event, noShift) {
        if (presto && event.keyCode == 34 && event['char']) {
            return false
        }
        var name = keyNames[event.keyCode]
        if (name == null || event.altGraphKey) {
            return false
        }
        // Ctrl-ScrollLock has keyCode 3, same as Ctrl-Pause,
        // so we'll use event.code when available (Chrome 48+, FF 38+, Safari 10.1+)
        if (event.keyCode == 3 && event.code) {
            name = event.code
        }
        return addModifierNames(name, event, noShift)
    }

    function getKeyMap(val) {
        return typeof val == 'string' ? keyMap[val] : val
    }

    // Helper for deleting text near the selection(s), used to implement
    // backspace, delete, and similar functionality.
    function deleteNearSelection(cm, compute) {
        var ranges = cm.doc.sel.ranges,
            kill = []
        // Build up a set of ranges to kill first, merging overlapping
        // ranges.
        for (var i = 0; i < ranges.length; i++) {
            var toKill = compute(ranges[i])
            while (kill.length && cmp(toKill.from, lst(kill).to) <= 0) {
                var replaced = kill.pop()
                if (cmp(replaced.from, toKill.from) < 0) {
                    toKill.from = replaced.from
                    break
                }
            }
            kill.push(toKill)
        }
        // Next, remove those actual ranges.
        runInOp(cm, function () {
            for (var i = kill.length - 1; i >= 0; i--) {
                replaceRange(cm.doc, '', kill[i].from, kill[i].to, '+delete')
            }
            ensureCursorVisible(cm)
        })
    }

    function moveCharLogically(line, ch, dir) {
        var target = skipExtendingChars(line.text, ch + dir, dir)
        return target < 0 || target > line.text.length ? null : target
    }

    function moveLogically(line, start, dir) {
        var ch = moveCharLogically(line, start.ch, dir)
        return ch == null ? null : new Pos(start.line, ch, dir < 0 ? 'after' : 'before')
    }

    function endOfLine(visually, cm, lineObj, lineNo, dir) {
        if (visually) {
            if (cm.doc.direction == 'rtl') {
                dir = -dir
            }
            var order = getOrder(lineObj, cm.doc.direction)
            if (order) {
                var part = dir < 0 ? lst(order) : order[0]
                var moveInStorageOrder = dir < 0 == (part.level == 1)
                var sticky = moveInStorageOrder ? 'after' : 'before'
                var ch
                // With a wrapped rtl chunk (possibly spanning multiple bidi parts),
                // it could be that the last bidi part is not on the last visual line,
                // since visual lines contain content order-consecutive chunks.
                // Thus, in rtl, we are looking for the first (content-order) character
                // in the rtl chunk that is on the last line (that is, the same line
                // as the last (content-order) character).
                if (part.level > 0 || cm.doc.direction == 'rtl') {
                    var prep = prepareMeasureForLine(cm, lineObj)
                    ch = dir < 0 ? lineObj.text.length - 1 : 0
                    var targetTop = measureCharPrepared(cm, prep, ch).top
                    ch = findFirst(
                        function (ch) {
                            return measureCharPrepared(cm, prep, ch).top == targetTop
                        },
                        dir < 0 == (part.level == 1) ? part.from : part.to - 1,
                        ch
                    )
                    if (sticky == 'before') {
                        ch = moveCharLogically(lineObj, ch, 1)
                    }
                } else {
                    ch = dir < 0 ? part.to : part.from
                }
                return new Pos(lineNo, ch, sticky)
            }
        }
        return new Pos(lineNo, dir < 0 ? lineObj.text.length : 0, dir < 0 ? 'before' : 'after')
    }

    function moveVisually(cm, line, start, dir) {
        var bidi = getOrder(line, cm.doc.direction)
        if (!bidi) {
            return moveLogically(line, start, dir)
        }
        if (start.ch >= line.text.length) {
            start.ch = line.text.length
            start.sticky = 'before'
        } else if (start.ch <= 0) {
            start.ch = 0
            start.sticky = 'after'
        }
        var partPos = getBidiPartAt(bidi, start.ch, start.sticky),
            part = bidi[partPos]
        if (cm.doc.direction == 'ltr' && part.level % 2 == 0 && (dir > 0 ? part.to > start.ch : part.from < start.ch)) {
            // Case 1: We move within an ltr part in an ltr editor. Even with wrapped lines,
            // nothing interesting happens.
            return moveLogically(line, start, dir)
        }

        var mv = function (pos, dir) {
            return moveCharLogically(line, pos instanceof Pos ? pos.ch : pos, dir)
        }
        var prep
        var getWrappedLineExtent = function (ch) {
            if (!cm.options.lineWrapping) {
                return { begin: 0, end: line.text.length }
            }
            prep = prep || prepareMeasureForLine(cm, line)
            return wrappedLineExtentChar(cm, line, prep, ch)
        }
        var wrappedLineExtent = getWrappedLineExtent(start.sticky == 'before' ? mv(start, -1) : start.ch)

        if (cm.doc.direction == 'rtl' || part.level == 1) {
            var moveInStorageOrder = (part.level == 1) == dir < 0
            var ch = mv(start, moveInStorageOrder ? 1 : -1)
            if (ch != null && (!moveInStorageOrder ? ch >= part.from && ch >= wrappedLineExtent.begin : ch <= part.to && ch <= wrappedLineExtent.end)) {
                // Case 2: We move within an rtl part or in an rtl editor on the same visual line
                var sticky = moveInStorageOrder ? 'before' : 'after'
                return new Pos(start.line, ch, sticky)
            }
        }

        // Case 3: Could not move within this bidi part in this visual line, so leave
        // the current bidi part

        var searchInVisualLine = function (partPos, dir, wrappedLineExtent) {
            var getRes = function (ch, moveInStorageOrder) {
                return moveInStorageOrder ? new Pos(start.line, mv(ch, 1), 'before') : new Pos(start.line, ch, 'after')
            }

            for (; partPos >= 0 && partPos < bidi.length; partPos += dir) {
                var part = bidi[partPos]
                var moveInStorageOrder = dir > 0 == (part.level != 1)
                var ch = moveInStorageOrder ? wrappedLineExtent.begin : mv(wrappedLineExtent.end, -1)
                if (part.from <= ch && ch < part.to) {
                    return getRes(ch, moveInStorageOrder)
                }
                ch = moveInStorageOrder ? part.from : mv(part.to, -1)
                if (wrappedLineExtent.begin <= ch && ch < wrappedLineExtent.end) {
                    return getRes(ch, moveInStorageOrder)
                }
            }
        }

        // Case 3a: Look for other bidi parts on the same visual line
        var res = searchInVisualLine(partPos + dir, dir, wrappedLineExtent)
        if (res) {
            return res
        }

        // Case 3b: Look for other bidi parts on the next visual line
        var nextCh = dir > 0 ? wrappedLineExtent.end : mv(wrappedLineExtent.begin, -1)
        if (nextCh != null && !(dir > 0 && nextCh == line.text.length)) {
            res = searchInVisualLine(dir > 0 ? 0 : bidi.length - 1, dir, getWrappedLineExtent(nextCh))
            if (res) {
                return res
            }
        }

        // Case 4: Nowhere to move
        return null
    }

    // Commands are parameter-less actions that can be performed on an
    // editor, mostly used for keybindings.
    var commands = {
        selectAll: selectAll,
        singleSelection: function (cm) {
            return cm.setSelection(cm.getCursor('anchor'), cm.getCursor('head'), sel_dontScroll)
        },
        killLine: function (cm) {
            return deleteNearSelection(cm, function (range) {
                if (range.empty()) {
                    var len = getLine(cm.doc, range.head.line).text.length
                    if (range.head.ch == len && range.head.line < cm.lastLine()) {
                        return { from: range.head, to: Pos(range.head.line + 1, 0) }
                    } else {
                        return { from: range.head, to: Pos(range.head.line, len) }
                    }
                } else {
                    return { from: range.from(), to: range.to() }
                }
            })
        },
        deleteLine: function (cm) {
            return deleteNearSelection(cm, function (range) {
                return {
                    from: Pos(range.from().line, 0),
                    to: clipPos(cm.doc, Pos(range.to().line + 1, 0)),
                }
            })
        },
        delLineLeft: function (cm) {
            return deleteNearSelection(cm, function (range) {
                return {
                    from: Pos(range.from().line, 0),
                    to: range.from(),
                }
            })
        },
        delWrappedLineLeft: function (cm) {
            return deleteNearSelection(cm, function (range) {
                var top = cm.charCoords(range.head, 'div').top + 5
                var leftPos = cm.coordsChar({ left: 0, top: top }, 'div')
                return { from: leftPos, to: range.from() }
            })
        },
        delWrappedLineRight: function (cm) {
            return deleteNearSelection(cm, function (range) {
                var top = cm.charCoords(range.head, 'div').top + 5
                var rightPos = cm.coordsChar({ left: cm.display.lineDiv.offsetWidth + 100, top: top }, 'div')
                return { from: range.from(), to: rightPos }
            })
        },
        undo: function (cm) {
            return cm.undo()
        },
        redo: function (cm) {
            return cm.redo()
        },
        undoSelection: function (cm) {
            return cm.undoSelection()
        },
        redoSelection: function (cm) {
            return cm.redoSelection()
        },
        goDocStart: function (cm) {
            return cm.extendSelection(Pos(cm.firstLine(), 0))
        },
        goDocEnd: function (cm) {
            return cm.extendSelection(Pos(cm.lastLine()))
        },
        goLineStart: function (cm) {
            return cm.extendSelectionsBy(
                function (range) {
                    return lineStart(cm, range.head.line)
                },
                { origin: '+move', bias: 1 }
            )
        },
        goLineStartSmart: function (cm) {
            return cm.extendSelectionsBy(
                function (range) {
                    return lineStartSmart(cm, range.head)
                },
                { origin: '+move', bias: 1 }
            )
        },
        goLineEnd: function (cm) {
            return cm.extendSelectionsBy(
                function (range) {
                    return lineEnd(cm, range.head.line)
                },
                { origin: '+move', bias: -1 }
            )
        },
        goLineRight: function (cm) {
            return cm.extendSelectionsBy(function (range) {
                var top = cm.cursorCoords(range.head, 'div').top + 5
                return cm.coordsChar({ left: cm.display.lineDiv.offsetWidth + 100, top: top }, 'div')
            }, sel_move)
        },
        goLineLeft: function (cm) {
            return cm.extendSelectionsBy(function (range) {
                var top = cm.cursorCoords(range.head, 'div').top + 5
                return cm.coordsChar({ left: 0, top: top }, 'div')
            }, sel_move)
        },
        goLineLeftSmart: function (cm) {
            return cm.extendSelectionsBy(function (range) {
                var top = cm.cursorCoords(range.head, 'div').top + 5
                var pos = cm.coordsChar({ left: 0, top: top }, 'div')
                if (pos.ch < cm.getLine(pos.line).search(/\S/)) {
                    return lineStartSmart(cm, range.head)
                }
                return pos
            }, sel_move)
        },
        goLineUp: function (cm) {
            return cm.moveV(-1, 'line')
        },
        goLineDown: function (cm) {
            return cm.moveV(1, 'line')
        },
        goPageUp: function (cm) {
            return cm.moveV(-1, 'page')
        },
        goPageDown: function (cm) {
            return cm.moveV(1, 'page')
        },
        goCharLeft: function (cm) {
            return cm.moveH(-1, 'char')
        },
        goCharRight: function (cm) {
            return cm.moveH(1, 'char')
        },
        goColumnLeft: function (cm) {
            return cm.moveH(-1, 'column')
        },
        goColumnRight: function (cm) {
            return cm.moveH(1, 'column')
        },
        goWordLeft: function (cm) {
            return cm.moveH(-1, 'word')
        },
        goGroupRight: function (cm) {
            return cm.moveH(1, 'group')
        },
        goGroupLeft: function (cm) {
            return cm.moveH(-1, 'group')
        },
        goWordRight: function (cm) {
            return cm.moveH(1, 'word')
        },
        delCharBefore: function (cm) {
            return cm.deleteH(-1, 'codepoint')
        },
        delCharAfter: function (cm) {
            return cm.deleteH(1, 'char')
        },
        delWordBefore: function (cm) {
            return cm.deleteH(-1, 'word')
        },
        delWordAfter: function (cm) {
            return cm.deleteH(1, 'word')
        },
        delGroupBefore: function (cm) {
            return cm.deleteH(-1, 'group')
        },
        delGroupAfter: function (cm) {
            return cm.deleteH(1, 'group')
        },
        indentAuto: function (cm) {
            return cm.indentSelection('smart')
        },
        indentMore: function (cm) {
            return cm.indentSelection('add')
        },
        indentLess: function (cm) {
            return cm.indentSelection('subtract')
        },
        insertTab: function (cm) {
            return cm.replaceSelection('\t')
        },
        insertSoftTab: function (cm) {
            var spaces = [],
                ranges = cm.listSelections(),
                tabSize = cm.options.tabSize
            for (var i = 0; i < ranges.length; i++) {
                var pos = ranges[i].from()
                var col = countColumn(cm.getLine(pos.line), pos.ch, tabSize)
                spaces.push(spaceStr(tabSize - (col % tabSize)))
            }
            cm.replaceSelections(spaces)
        },
        defaultTab: function (cm) {
            if (cm.somethingSelected()) {
                cm.indentSelection('add')
            } else {
                cm.execCommand('insertTab')
            }
        },
        // Swap the two chars left and right of each selection's head.
        // Move cursor behind the two swapped characters afterwards.
        //
        // Doesn't consider line feeds a character.
        // Doesn't scan more than one line above to find a character.
        // Doesn't do anything on an empty line.
        // Doesn't do anything with non-empty selections.
        transposeChars: function (cm) {
            return runInOp(cm, function () {
                var ranges = cm.listSelections(),
                    newSel = []
                for (var i = 0; i < ranges.length; i++) {
                    if (!ranges[i].empty()) {
                        continue
                    }
                    var cur = ranges[i].head,
                        line = getLine(cm.doc, cur.line).text
                    if (line) {
                        if (cur.ch == line.length) {
                            cur = new Pos(cur.line, cur.ch - 1)
                        }
                        if (cur.ch > 0) {
                            cur = new Pos(cur.line, cur.ch + 1)
                            cm.replaceRange(line.charAt(cur.ch - 1) + line.charAt(cur.ch - 2), Pos(cur.line, cur.ch - 2), cur, '+transpose')
                        } else if (cur.line > cm.doc.first) {
                            var prev = getLine(cm.doc, cur.line - 1).text
                            if (prev) {
                                cur = new Pos(cur.line, 1)
                                cm.replaceRange(line.charAt(0) + cm.doc.lineSeparator() + prev.charAt(prev.length - 1), Pos(cur.line - 1, prev.length - 1), cur, '+transpose')
                            }
                        }
                    }
                    newSel.push(new Range(cur, cur))
                }
                cm.setSelections(newSel)
            })
        },
        newlineAndIndent: function (cm) {
            return runInOp(cm, function () {
                var sels = cm.listSelections()
                for (var i = sels.length - 1; i >= 0; i--) {
                    cm.replaceRange(cm.doc.lineSeparator(), sels[i].anchor, sels[i].head, '+input')
                }
                sels = cm.listSelections()
                for (var i$1 = 0; i$1 < sels.length; i$1++) {
                    cm.indentLine(sels[i$1].from().line, null, true)
                }
                ensureCursorVisible(cm)
            })
        },
        openLine: function (cm) {
            return cm.replaceSelection('\n', 'start')
        },
        toggleOverwrite: function (cm) {
            return cm.toggleOverwrite()
        },
    }

    function lineStart(cm, lineN) {
        var line = getLine(cm.doc, lineN)
        var visual = visualLine(line)
        if (visual != line) {
            lineN = lineNo(visual)
        }
        return endOfLine(true, cm, visual, lineN, 1)
    }
    function lineEnd(cm, lineN) {
        var line = getLine(cm.doc, lineN)
        var visual = visualLineEnd(line)
        if (visual != line) {
            lineN = lineNo(visual)
        }
        return endOfLine(true, cm, line, lineN, -1)
    }
    function lineStartSmart(cm, pos) {
        var start = lineStart(cm, pos.line)
        var line = getLine(cm.doc, start.line)
        var order = getOrder(line, cm.doc.direction)
        if (!order || order[0].level == 0) {
            var firstNonWS = Math.max(start.ch, line.text.search(/\S/))
            var inWS = pos.line == start.line && pos.ch <= firstNonWS && pos.ch
            return Pos(start.line, inWS ? 0 : firstNonWS, start.sticky)
        }
        return start
    }

    // Run a handler that was bound to a key.
    function doHandleBinding(cm, bound, dropShift) {
        if (typeof bound == 'string') {
            bound = commands[bound]
            if (!bound) {
                return false
            }
        }
        // Ensure previous input has been read, so that the handler sees a
        // consistent view of the document
        cm.display.input.ensurePolled()
        var prevShift = cm.display.shift,
            done = false
        try {
            if (cm.isReadOnly()) {
                cm.state.suppressEdits = true
            }
            if (dropShift) {
                cm.display.shift = false
            }
            done = bound(cm) != Pass
        } finally {
            cm.display.shift = prevShift
            cm.state.suppressEdits = false
        }
        return done
    }

    function lookupKeyForEditor(cm, name, handle) {
        for (var i = 0; i < cm.state.keyMaps.length; i++) {
            var result = lookupKey(name, cm.state.keyMaps[i], handle, cm)
            if (result) {
                return result
            }
        }
        return (cm.options.extraKeys && lookupKey(name, cm.options.extraKeys, handle, cm)) || lookupKey(name, cm.options.keyMap, handle, cm)
    }

    // Note that, despite the name, this function is also used to check
    // for bound mouse clicks.

    var stopSeq = new Delayed()

    function dispatchKey(cm, name, e, handle) {
        var seq = cm.state.keySeq
        if (seq) {
            if (isModifierKey(name)) {
                return 'handled'
            }
            if (/\'$/.test(name)) {
                cm.state.keySeq = null
            } else {
                stopSeq.set(50, function () {
                    if (cm.state.keySeq == seq) {
                        cm.state.keySeq = null
                        cm.display.input.reset()
                    }
                })
            }
            if (dispatchKeyInner(cm, seq + ' ' + name, e, handle)) {
                return true
            }
        }
        return dispatchKeyInner(cm, name, e, handle)
    }

    function dispatchKeyInner(cm, name, e, handle) {
        var result = lookupKeyForEditor(cm, name, handle)

        if (result == 'multi') {
            cm.state.keySeq = name
        }
        if (result == 'handled') {
            signalLater(cm, 'keyHandled', cm, name, e)
        }

        if (result == 'handled' || result == 'multi') {
            e_preventDefault(e)
            restartBlink(cm)
        }

        return !!result
    }

    // Handle a key from the keydown event.
    function handleKeyBinding(cm, e) {
        var name = keyName(e, true)
        if (!name) {
            return false
        }

        if (e.shiftKey && !cm.state.keySeq) {
            // First try to resolve full name (including 'Shift-'). Failing
            // that, see if there is a cursor-motion command (starting with
            // 'go') bound to the keyname without 'Shift-'.
            return (
                dispatchKey(cm, 'Shift-' + name, e, function (b) {
                    return doHandleBinding(cm, b, true)
                }) ||
                dispatchKey(cm, name, e, function (b) {
                    if (typeof b == 'string' ? /^go[A-Z]/.test(b) : b.motion) {
                        return doHandleBinding(cm, b)
                    }
                })
            )
        } else {
            return dispatchKey(cm, name, e, function (b) {
                return doHandleBinding(cm, b)
            })
        }
    }

    // Handle a key from the keypress event
    function handleCharBinding(cm, e, ch) {
        return dispatchKey(cm, "'" + ch + "'", e, function (b) {
            return doHandleBinding(cm, b, true)
        })
    }

    var lastStoppedKey = null
    function onKeyDown(e) {
        var cm = this
        if (e.target && e.target != cm.display.input.getField()) {
            return
        }
        cm.curOp.focus = activeElt()
        if (signalDOMEvent(cm, e)) {
            return
        }
        // IE does strange things with escape.
        if (ie && ie_version < 11 && e.keyCode == 27) {
            e.returnValue = false
        }
        var code = e.keyCode
        cm.display.shift = code == 16 || e.shiftKey
        var handled = handleKeyBinding(cm, e)
        if (presto) {
            lastStoppedKey = handled ? code : null
            // Opera has no cut event... we try to at least catch the key combo
            if (!handled && code == 88 && !hasCopyEvent && (mac ? e.metaKey : e.ctrlKey)) {
                cm.replaceSelection('', null, 'cut')
            }
        }
        if (gecko && !mac && !handled && code == 46 && e.shiftKey && !e.ctrlKey && document.execCommand) {
            document.execCommand('cut')
        }

        // Turn mouse into crosshair when Alt is held on Mac.
        if (code == 18 && !/\bCodeMirror-crosshair\b/.test(cm.display.lineDiv.className)) {
            showCrossHair(cm)
        }
    }

    function showCrossHair(cm) {
        var lineDiv = cm.display.lineDiv
        addClass(lineDiv, 'CodeMirror-crosshair')

        function up(e) {
            if (e.keyCode == 18 || !e.altKey) {
                rmClass(lineDiv, 'CodeMirror-crosshair')
                off(document, 'keyup', up)
                off(document, 'mouseover', up)
            }
        }
        on(document, 'keyup', up)
        on(document, 'mouseover', up)
    }

    function onKeyUp(e) {
        if (e.keyCode == 16) {
            this.doc.sel.shift = false
        }
        signalDOMEvent(this, e)
    }

    function onKeyPress(e) {
        var cm = this
        if (e.target && e.target != cm.display.input.getField()) {
            return
        }
        if (eventInWidget(cm.display, e) || signalDOMEvent(cm, e) || (e.ctrlKey && !e.altKey) || (mac && e.metaKey)) {
            return
        }
        var keyCode = e.keyCode,
            charCode = e.charCode
        if (presto && keyCode == lastStoppedKey) {
            lastStoppedKey = null
            e_preventDefault(e)
            return
        }
        if (presto && (!e.which || e.which < 10) && handleKeyBinding(cm, e)) {
            return
        }
        var ch = String.fromCharCode(charCode == null ? keyCode : charCode)
        // Some browsers fire keypress events for backspace
        if (ch == '\x08') {
            return
        }
        if (handleCharBinding(cm, e, ch)) {
            return
        }
        cm.display.input.onKeyPress(e)
    }

    var DOUBLECLICK_DELAY = 400

    var PastClick = function (time, pos, button) {
        this.time = time
        this.pos = pos
        this.button = button
    }

    PastClick.prototype.compare = function (time, pos, button) {
        return this.time + DOUBLECLICK_DELAY > time && cmp(pos, this.pos) == 0 && button == this.button
    }

    var lastClick, lastDoubleClick
    function clickRepeat(pos, button) {
        var now = +new Date()
        if (lastDoubleClick && lastDoubleClick.compare(now, pos, button)) {
            lastClick = lastDoubleClick = null
            return 'triple'
        } else if (lastClick && lastClick.compare(now, pos, button)) {
            lastDoubleClick = new PastClick(now, pos, button)
            lastClick = null
            return 'double'
        } else {
            lastClick = new PastClick(now, pos, button)
            lastDoubleClick = null
            return 'single'
        }
    }

    // A mouse down can be a single click, double click, triple click,
    // start of selection drag, start of text drag, new cursor
    // (ctrl-click), rectangle drag (alt-drag), or xwin
    // middle-click-paste. Or it might be a click on something we should
    // not interfere with, such as a scrollbar or widget.
    function onMouseDown(e) {
        var cm = this,
            display = cm.display
        if (signalDOMEvent(cm, e) || (display.activeTouch && display.input.supportsTouch())) {
            return
        }
        display.input.ensurePolled()
        display.shift = e.shiftKey

        if (eventInWidget(display, e)) {
            if (!webkit) {
                // Briefly turn off draggability, to allow widgets to do
                // normal dragging things.
                display.scroller.draggable = false
                setTimeout(function () {
                    return (display.scroller.draggable = true)
                }, 100)
            }
            return
        }
        if (clickInGutter(cm, e)) {
            return
        }
        var pos = posFromMouse(cm, e),
            button = e_button(e),
            repeat = pos ? clickRepeat(pos, button) : 'single'
        window.focus()

        // #3261: make sure, that we're not starting a second selection
        if (button == 1 && cm.state.selectingText) {
            cm.state.selectingText(e)
        }

        if (pos && handleMappedButton(cm, button, pos, repeat, e)) {
            return
        }

        if (button == 1) {
            if (pos) {
                leftButtonDown(cm, pos, repeat, e)
            } else if (e_target(e) == display.scroller) {
                e_preventDefault(e)
            }
        } else if (button == 2) {
            if (pos) {
                extendSelection(cm.doc, pos)
            }
            setTimeout(function () {
                return display.input.focus()
            }, 20)
        } else if (button == 3) {
            if (captureRightClick) {
                cm.display.input.onContextMenu(e)
            } else {
                delayBlurEvent(cm)
            }
        }
    }

    function handleMappedButton(cm, button, pos, repeat, event) {
        var name = 'Click'
        if (repeat == 'double') {
            name = 'Double' + name
        } else if (repeat == 'triple') {
            name = 'Triple' + name
        }
        name = (button == 1 ? 'Left' : button == 2 ? 'Middle' : 'Right') + name

        return dispatchKey(cm, addModifierNames(name, event), event, function (bound) {
            if (typeof bound == 'string') {
                bound = commands[bound]
            }
            if (!bound) {
                return false
            }
            var done = false
            try {
                if (cm.isReadOnly()) {
                    cm.state.suppressEdits = true
                }
                done = bound(cm, pos) != Pass
            } finally {
                cm.state.suppressEdits = false
            }
            return done
        })
    }

    function configureMouse(cm, repeat, event) {
        var option = cm.getOption('configureMouse')
        var value = option ? option(cm, repeat, event) : {}
        if (value.unit == null) {
            var rect = chromeOS ? event.shiftKey && event.metaKey : event.altKey
            value.unit = rect ? 'rectangle' : repeat == 'single' ? 'char' : repeat == 'double' ? 'word' : 'line'
        }
        if (value.extend == null || cm.doc.extend) {
            value.extend = cm.doc.extend || event.shiftKey
        }
        if (value.addNew == null) {
            value.addNew = mac ? event.metaKey : event.ctrlKey
        }
        if (value.moveOnDrag == null) {
            value.moveOnDrag = !(mac ? event.altKey : event.ctrlKey)
        }
        return value
    }

    function leftButtonDown(cm, pos, repeat, event) {
        if (ie) {
            setTimeout(bind(ensureFocus, cm), 0)
        } else {
            cm.curOp.focus = activeElt()
        }

        var behavior = configureMouse(cm, repeat, event)

        var sel = cm.doc.sel,
            contained
        if (
            cm.options.dragDrop &&
            dragAndDrop &&
            !cm.isReadOnly() &&
            repeat == 'single' &&
            (contained = sel.contains(pos)) > -1 &&
            (cmp((contained = sel.ranges[contained]).from(), pos) < 0 || pos.xRel > 0) &&
            (cmp(contained.to(), pos) > 0 || pos.xRel < 0)
        ) {
            leftButtonStartDrag(cm, event, pos, behavior)
        } else {
            leftButtonSelect(cm, event, pos, behavior)
        }
    }

    // Start a text drag. When it ends, see if any dragging actually
    // happen, and treat as a click if it didn't.
    function leftButtonStartDrag(cm, event, pos, behavior) {
        var display = cm.display,
            moved = false
        var dragEnd = operation(cm, function (e) {
            if (webkit) {
                display.scroller.draggable = false
            }
            cm.state.draggingText = false
            if (cm.state.delayingBlurEvent) {
                if (cm.hasFocus()) {
                    cm.state.delayingBlurEvent = false
                } else {
                    delayBlurEvent(cm)
                }
            }
            off(display.wrapper.ownerDocument, 'mouseup', dragEnd)
            off(display.wrapper.ownerDocument, 'mousemove', mouseMove)
            off(display.scroller, 'dragstart', dragStart)
            off(display.scroller, 'drop', dragEnd)
            if (!moved) {
                e_preventDefault(e)
                if (!behavior.addNew) {
                    extendSelection(cm.doc, pos, null, null, behavior.extend)
                }
                // Work around unexplainable focus problem in IE9 (#2127) and Chrome (#3081)
                if ((webkit && !safari) || (ie && ie_version == 9)) {
                    setTimeout(function () {
                        display.wrapper.ownerDocument.body.focus({ preventScroll: true })
                        display.input.focus()
                    }, 20)
                } else {
                    display.input.focus()
                }
            }
        })
        var mouseMove = function (e2) {
            moved = moved || Math.abs(event.clientX - e2.clientX) + Math.abs(event.clientY - e2.clientY) >= 10
        }
        var dragStart = function () {
            return (moved = true)
        }
        // Let the drag handler handle this.
        if (webkit) {
            display.scroller.draggable = true
        }
        cm.state.draggingText = dragEnd
        dragEnd.copy = !behavior.moveOnDrag
        on(display.wrapper.ownerDocument, 'mouseup', dragEnd)
        on(display.wrapper.ownerDocument, 'mousemove', mouseMove)
        on(display.scroller, 'dragstart', dragStart)
        on(display.scroller, 'drop', dragEnd)

        cm.state.delayingBlurEvent = true
        setTimeout(function () {
            return display.input.focus()
        }, 20)
        // IE's approach to draggable
        if (display.scroller.dragDrop) {
            display.scroller.dragDrop()
        }
    }

    function rangeForUnit(cm, pos, unit) {
        if (unit == 'char') {
            return new Range(pos, pos)
        }
        if (unit == 'word') {
            return cm.findWordAt(pos)
        }
        if (unit == 'line') {
            return new Range(Pos(pos.line, 0), clipPos(cm.doc, Pos(pos.line + 1, 0)))
        }
        var result = unit(cm, pos)
        return new Range(result.from, result.to)
    }

    // Normal selection, as opposed to text dragging.
    function leftButtonSelect(cm, event, start, behavior) {
        if (ie) {
            delayBlurEvent(cm)
        }
        var display = cm.display,
            doc = cm.doc
        e_preventDefault(event)

        var ourRange,
            ourIndex,
            startSel = doc.sel,
            ranges = startSel.ranges
        if (behavior.addNew && !behavior.extend) {
            ourIndex = doc.sel.contains(start)
            if (ourIndex > -1) {
                ourRange = ranges[ourIndex]
            } else {
                ourRange = new Range(start, start)
            }
        } else {
            ourRange = doc.sel.primary()
            ourIndex = doc.sel.primIndex
        }

        if (behavior.unit == 'rectangle') {
            if (!behavior.addNew) {
                ourRange = new Range(start, start)
            }
            start = posFromMouse(cm, event, true, true)
            ourIndex = -1
        } else {
            var range = rangeForUnit(cm, start, behavior.unit)
            if (behavior.extend) {
                ourRange = extendRange(ourRange, range.anchor, range.head, behavior.extend)
            } else {
                ourRange = range
            }
        }

        if (!behavior.addNew) {
            ourIndex = 0
            setSelection(doc, new Selection([ourRange], 0), sel_mouse)
            startSel = doc.sel
        } else if (ourIndex == -1) {
            ourIndex = ranges.length
            setSelection(doc, normalizeSelection(cm, ranges.concat([ourRange]), ourIndex), { scroll: false, origin: '*mouse' })
        } else if (ranges.length > 1 && ranges[ourIndex].empty() && behavior.unit == 'char' && !behavior.extend) {
            setSelection(doc, normalizeSelection(cm, ranges.slice(0, ourIndex).concat(ranges.slice(ourIndex + 1)), 0), { scroll: false, origin: '*mouse' })
            startSel = doc.sel
        } else {
            replaceOneSelection(doc, ourIndex, ourRange, sel_mouse)
        }

        var lastPos = start
        function extendTo(pos) {
            if (cmp(lastPos, pos) == 0) {
                return
            }
            lastPos = pos

            if (behavior.unit == 'rectangle') {
                var ranges = [],
                    tabSize = cm.options.tabSize
                var startCol = countColumn(getLine(doc, start.line).text, start.ch, tabSize)
                var posCol = countColumn(getLine(doc, pos.line).text, pos.ch, tabSize)
                var left = Math.min(startCol, posCol),
                    right = Math.max(startCol, posCol)
                for (var line = Math.min(start.line, pos.line), end = Math.min(cm.lastLine(), Math.max(start.line, pos.line)); line <= end; line++) {
                    var text = getLine(doc, line).text,
                        leftPos = findColumn(text, left, tabSize)
                    if (left == right) {
                        ranges.push(new Range(Pos(line, leftPos), Pos(line, leftPos)))
                    } else if (text.length > leftPos) {
                        ranges.push(new Range(Pos(line, leftPos), Pos(line, findColumn(text, right, tabSize))))
                    }
                }
                if (!ranges.length) {
                    ranges.push(new Range(start, start))
                }
                setSelection(doc, normalizeSelection(cm, startSel.ranges.slice(0, ourIndex).concat(ranges), ourIndex), { origin: '*mouse', scroll: false })
                cm.scrollIntoView(pos)
            } else {
                var oldRange = ourRange
                var range = rangeForUnit(cm, pos, behavior.unit)
                var anchor = oldRange.anchor,
                    head
                if (cmp(range.anchor, anchor) > 0) {
                    head = range.head
                    anchor = minPos(oldRange.from(), range.anchor)
                } else {
                    head = range.anchor
                    anchor = maxPos(oldRange.to(), range.head)
                }
                var ranges$1 = startSel.ranges.slice(0)
                ranges$1[ourIndex] = bidiSimplify(cm, new Range(clipPos(doc, anchor), head))
                setSelection(doc, normalizeSelection(cm, ranges$1, ourIndex), sel_mouse)
            }
        }

        var editorSize = display.wrapper.getBoundingClientRect()
        // Used to ensure timeout re-tries don't fire when another extend
        // happened in the meantime (clearTimeout isn't reliable -- at
        // least on Chrome, the timeouts still happen even when cleared,
        // if the clear happens after their scheduled firing time).
        var counter = 0

        function extend(e) {
            var curCount = ++counter
            var cur = posFromMouse(cm, e, true, behavior.unit == 'rectangle')
            if (!cur) {
                return
            }
            if (cmp(cur, lastPos) != 0) {
                cm.curOp.focus = activeElt()
                extendTo(cur)
                var visible = visibleLines(display, doc)
                if (cur.line >= visible.to || cur.line < visible.from) {
                    setTimeout(
                        operation(cm, function () {
                            if (counter == curCount) {
                                extend(e)
                            }
                        }),
                        150
                    )
                }
            } else {
                var outside = e.clientY < editorSize.top ? -20 : e.clientY > editorSize.bottom ? 20 : 0
                if (outside) {
                    setTimeout(
                        operation(cm, function () {
                            if (counter != curCount) {
                                return
                            }
                            display.scroller.scrollTop += outside
                            extend(e)
                        }),
                        50
                    )
                }
            }
        }

        function done(e) {
            cm.state.selectingText = false
            counter = Infinity
            // If e is null or undefined we interpret this as someone trying
            // to explicitly cancel the selection rather than the user
            // letting go of the mouse button.
            if (e) {
                e_preventDefault(e)
                display.input.focus()
            }
            off(display.wrapper.ownerDocument, 'mousemove', move)
            off(display.wrapper.ownerDocument, 'mouseup', up)
            doc.history.lastSelOrigin = null
        }

        var move = operation(cm, function (e) {
            if (e.buttons === 0 || !e_button(e)) {
                done(e)
            } else {
                extend(e)
            }
        })
        var up = operation(cm, done)
        cm.state.selectingText = up
        on(display.wrapper.ownerDocument, 'mousemove', move)
        on(display.wrapper.ownerDocument, 'mouseup', up)
    }

    // Used when mouse-selecting to adjust the anchor to the proper side
    // of a bidi jump depending on the visual position of the head.
    function bidiSimplify(cm, range) {
        var anchor = range.anchor
        var head = range.head
        var anchorLine = getLine(cm.doc, anchor.line)
        if (cmp(anchor, head) == 0 && anchor.sticky == head.sticky) {
            return range
        }
        var order = getOrder(anchorLine)
        if (!order) {
            return range
        }
        var index = getBidiPartAt(order, anchor.ch, anchor.sticky),
            part = order[index]
        if (part.from != anchor.ch && part.to != anchor.ch) {
            return range
        }
        var boundary = index + ((part.from == anchor.ch) == (part.level != 1) ? 0 : 1)
        if (boundary == 0 || boundary == order.length) {
            return range
        }

        // Compute the relative visual position of the head compared to the
        // anchor (<0 is to the left, >0 to the right)
        var leftSide
        if (head.line != anchor.line) {
            leftSide = (head.line - anchor.line) * (cm.doc.direction == 'ltr' ? 1 : -1) > 0
        } else {
            var headIndex = getBidiPartAt(order, head.ch, head.sticky)
            var dir = headIndex - index || (head.ch - anchor.ch) * (part.level == 1 ? -1 : 1)
            if (headIndex == boundary - 1 || headIndex == boundary) {
                leftSide = dir < 0
            } else {
                leftSide = dir > 0
            }
        }

        var usePart = order[boundary + (leftSide ? -1 : 0)]
        var from = leftSide == (usePart.level == 1)
        var ch = from ? usePart.from : usePart.to,
            sticky = from ? 'after' : 'before'
        return anchor.ch == ch && anchor.sticky == sticky ? range : new Range(new Pos(anchor.line, ch, sticky), head)
    }

    // Determines whether an event happened in the gutter, and fires the
    // handlers for the corresponding event.
    function gutterEvent(cm, e, type, prevent) {
        var mX, mY
        if (e.touches) {
            mX = e.touches[0].clientX
            mY = e.touches[0].clientY
        } else {
            try {
                mX = e.clientX
                mY = e.clientY
            } catch (e$1) {
                return false
            }
        }
        if (mX >= Math.floor(cm.display.gutters.getBoundingClientRect().right)) {
            return false
        }
        if (prevent) {
            e_preventDefault(e)
        }

        var display = cm.display
        var lineBox = display.lineDiv.getBoundingClientRect()

        if (mY > lineBox.bottom || !hasHandler(cm, type)) {
            return e_defaultPrevented(e)
        }
        mY -= lineBox.top - display.viewOffset

        for (var i = 0; i < cm.display.gutterSpecs.length; ++i) {
            var g = display.gutters.childNodes[i]
            if (g && g.getBoundingClientRect().right >= mX) {
                var line = lineAtHeight(cm.doc, mY)
                var gutter = cm.display.gutterSpecs[i]
                signal(cm, type, cm, line, gutter.className, e)
                return e_defaultPrevented(e)
            }
        }
    }

    function clickInGutter(cm, e) {
        return gutterEvent(cm, e, 'gutterClick', true)
    }

    // CONTEXT MENU HANDLING

    // To make the context menu work, we need to briefly unhide the
    // textarea (making it as unobtrusive as possible) to let the
    // right-click take effect on it.
    function onContextMenu(cm, e) {
        if (eventInWidget(cm.display, e) || contextMenuInGutter(cm, e)) {
            return
        }
        if (signalDOMEvent(cm, e, 'contextmenu')) {
            return
        }
        if (!captureRightClick) {
            cm.display.input.onContextMenu(e)
        }
    }

    function contextMenuInGutter(cm, e) {
        if (!hasHandler(cm, 'gutterContextMenu')) {
            return false
        }
        return gutterEvent(cm, e, 'gutterContextMenu', false)
    }

    function themeChanged(cm) {
        cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, '') + cm.options.theme.replace(/(^|\s)\s*/g, ' cm-s-')
        clearCaches(cm)
    }

    var Init = {
        toString: function () {
            return 'CodeMirror.Init'
        },
    }

    var defaults = {}
    var optionHandlers = {}

    function defineOptions(CodeMirror) {
        var optionHandlers = CodeMirror.optionHandlers

        function option(name, deflt, handle, notOnInit) {
            CodeMirror.defaults[name] = deflt
            if (handle) {
                optionHandlers[name] = notOnInit
                    ? function (cm, val, old) {
                          if (old != Init) {
                              handle(cm, val, old)
                          }
                      }
                    : handle
            }
        }

        CodeMirror.defineOption = option

        // Passed to option handlers when there is no old value.
        CodeMirror.Init = Init

        // These two are, on init, called from the constructor because they
        // have to be initialized before the editor can start at all.
        option(
            'value',
            '',
            function (cm, val) {
                return cm.setValue(val)
            },
            true
        )
        option(
            'mode',
            null,
            function (cm, val) {
                cm.doc.modeOption = val
                loadMode(cm)
            },
            true
        )

        option('indentUnit', 2, loadMode, true)
        option('indentWithTabs', false)
        option('smartIndent', true)
        option(
            'tabSize',
            4,
            function (cm) {
                resetModeState(cm)
                clearCaches(cm)
                regChange(cm)
            },
            true
        )

        option('lineSeparator', null, function (cm, val) {
            cm.doc.lineSep = val
            if (!val) {
                return
            }
            var newBreaks = [],
                lineNo = cm.doc.first
            cm.doc.iter(function (line) {
                for (var pos = 0; ; ) {
                    var found = line.text.indexOf(val, pos)
                    if (found == -1) {
                        break
                    }
                    pos = found + val.length
                    newBreaks.push(Pos(lineNo, found))
                }
                lineNo++
            })
            for (var i = newBreaks.length - 1; i >= 0; i--) {
                replaceRange(cm.doc, val, newBreaks[i], Pos(newBreaks[i].line, newBreaks[i].ch + val.length))
            }
        })
        option('specialChars', /[\u0000-\u001f\u007f-\u009f\u00ad\u061c\u200b\u200e\u200f\u2028\u2029\ufeff\ufff9-\ufffc]/g, function (cm, val, old) {
            cm.state.specialChars = new RegExp(val.source + (val.test('\t') ? '' : '|\t'), 'g')
            if (old != Init) {
                cm.refresh()
            }
        })
        option(
            'specialCharPlaceholder',
            defaultSpecialCharPlaceholder,
            function (cm) {
                return cm.refresh()
            },
            true
        )
        option('electricChars', true)
        option(
            'inputStyle',
            mobile ? 'contenteditable' : 'textarea',
            function () {
                throw new Error('inputStyle can not (yet) be changed in a running editor') // FIXME
            },
            true
        )
        option(
            'spellcheck',
            false,
            function (cm, val) {
                return (cm.getInputField().spellcheck = val)
            },
            true
        )
        option(
            'autocorrect',
            false,
            function (cm, val) {
                return (cm.getInputField().autocorrect = val)
            },
            true
        )
        option(
            'autocapitalize',
            false,
            function (cm, val) {
                return (cm.getInputField().autocapitalize = val)
            },
            true
        )
        option('rtlMoveVisually', !windows)
        option('wholeLineUpdateBefore', true)

        option(
            'theme',
            'default',
            function (cm) {
                themeChanged(cm)
                updateGutters(cm)
            },
            true
        )
        option('keyMap', 'default', function (cm, val, old) {
            var next = getKeyMap(val)
            var prev = old != Init && getKeyMap(old)
            if (prev && prev.detach) {
                prev.detach(cm, next)
            }
            if (next.attach) {
                next.attach(cm, prev || null)
            }
        })
        option('extraKeys', null)
        option('configureMouse', null)

        option('lineWrapping', false, wrappingChanged, true)
        option(
            'gutters',
            [],
            function (cm, val) {
                cm.display.gutterSpecs = getGutters(val, cm.options.lineNumbers)
                updateGutters(cm)
            },
            true
        )
        option(
            'fixedGutter',
            true,
            function (cm, val) {
                cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + 'px' : '0'
                cm.refresh()
            },
            true
        )
        option(
            'coverGutterNextToScrollbar',
            false,
            function (cm) {
                return updateScrollbars(cm)
            },
            true
        )
        option(
            'scrollbarStyle',
            'native',
            function (cm) {
                initScrollbars(cm)
                updateScrollbars(cm)
                cm.display.scrollbars.setScrollTop(cm.doc.scrollTop)
                cm.display.scrollbars.setScrollLeft(cm.doc.scrollLeft)
            },
            true
        )
        option(
            'lineNumbers',
            false,
            function (cm, val) {
                cm.display.gutterSpecs = getGutters(cm.options.gutters, val)
                updateGutters(cm)
            },
            true
        )
        option('firstLineNumber', 1, updateGutters, true)
        option(
            'lineNumberFormatter',
            function (integer) {
                return integer
            },
            updateGutters,
            true
        )
        option('showCursorWhenSelecting', false, updateSelection, true)

        option('resetSelectionOnContextMenu', true)
        option('lineWiseCopyCut', true)
        option('pasteLinesPerSelection', true)
        option('selectionsMayTouch', false)

        option('readOnly', false, function (cm, val) {
            if (val == 'nocursor') {
                onBlur(cm)
                cm.display.input.blur()
            }
            cm.display.input.readOnlyChanged(val)
        })

        option('screenReaderLabel', null, function (cm, val) {
            val = val === '' ? null : val
            cm.display.input.screenReaderLabelChanged(val)
        })

        option(
            'disableInput',
            false,
            function (cm, val) {
                if (!val) {
                    cm.display.input.reset()
                }
            },
            true
        )
        option('dragDrop', true, dragDropChanged)
        option('allowDropFileTypes', null)

        option('cursorBlinkRate', 530)
        option('cursorScrollMargin', 0)
        option('cursorHeight', 1, updateSelection, true)
        option('singleCursorHeightPerLine', true, updateSelection, true)
        option('workTime', 100)
        option('workDelay', 100)
        option('flattenSpans', true, resetModeState, true)
        option('addModeClass', false, resetModeState, true)
        option('pollInterval', 100)
        option('undoDepth', 200, function (cm, val) {
            return (cm.doc.history.undoDepth = val)
        })
        option('historyEventDelay', 1250)
        option(
            'viewportMargin',
            10,
            function (cm) {
                return cm.refresh()
            },
            true
        )
        option('maxHighlightLength', 10000, resetModeState, true)
        option('moveInputWithCursor', true, function (cm, val) {
            if (!val) {
                cm.display.input.resetPosition()
            }
        })

        option('tabindex', null, function (cm, val) {
            return (cm.display.input.getField().tabIndex = val || '')
        })
        option('autofocus', null)
        option(
            'direction',
            'ltr',
            function (cm, val) {
                return cm.doc.setDirection(val)
            },
            true
        )
        option('phrases', null)
    }

    function dragDropChanged(cm, value, old) {
        var wasOn = old && old != Init
        if (!value != !wasOn) {
            var funcs = cm.display.dragFunctions
            var toggle = value ? on : off
            toggle(cm.display.scroller, 'dragstart', funcs.start)
            toggle(cm.display.scroller, 'dragenter', funcs.enter)
            toggle(cm.display.scroller, 'dragover', funcs.over)
            toggle(cm.display.scroller, 'dragleave', funcs.leave)
            toggle(cm.display.scroller, 'drop', funcs.drop)
        }
    }

    function wrappingChanged(cm) {
        if (cm.options.lineWrapping) {
            addClass(cm.display.wrapper, 'CodeMirror-wrap')
            cm.display.sizer.style.minWidth = ''
            cm.display.sizerWidth = null
        } else {
            rmClass(cm.display.wrapper, 'CodeMirror-wrap')
            findMaxLine(cm)
        }
        estimateLineHeights(cm)
        regChange(cm)
        clearCaches(cm)
        setTimeout(function () {
            return updateScrollbars(cm)
        }, 100)
    }

    // A CodeMirror instance represents an editor. This is the object
    // that user code is usually dealing with.

    function CodeMirror(place, options) {
        var this$1 = this

        if (!(this instanceof CodeMirror)) {
            return new CodeMirror(place, options)
        }

        this.options = options = options ? copyObj(options) : {}
        // Determine effective options based on given values and defaults.
        copyObj(defaults, options, false)

        var doc = options.value
        if (typeof doc == 'string') {
            doc = new Doc(doc, options.mode, null, options.lineSeparator, options.direction)
        } else if (options.mode) {
            doc.modeOption = options.mode
        }
        this.doc = doc

        var input = new CodeMirror.inputStyles[options.inputStyle](this)
        var display = (this.display = new Display(place, doc, input, options))
        display.wrapper.CodeMirror = this
        themeChanged(this)
        if (options.lineWrapping) {
            this.display.wrapper.className += ' CodeMirror-wrap'
        }
        initScrollbars(this)

        this.state = {
            keyMaps: [], // stores maps added by addKeyMap
            overlays: [], // highlighting overlays, as added by addOverlay
            modeGen: 0, // bumped when mode/overlay changes, used to invalidate highlighting info
            overwrite: false,
            delayingBlurEvent: false,
            focused: false,
            suppressEdits: false, // used to disable editing during key handlers when in readOnly mode
            pasteIncoming: -1,
            cutIncoming: -1, // help recognize paste/cut edits in input.poll
            selectingText: false,
            draggingText: false,
            highlight: new Delayed(), // stores highlight worker timeout
            keySeq: null, // Unfinished key sequence
            specialChars: null,
        }

        if (options.autofocus && !mobile) {
            display.input.focus()
        }

        // Override magic textarea content restore that IE sometimes does
        // on our hidden textarea on reload
        if (ie && ie_version < 11) {
            setTimeout(function () {
                return this$1.display.input.reset(true)
            }, 20)
        }

        registerEventHandlers(this)
        ensureGlobalHandlers()

        startOperation(this)
        this.curOp.forceUpdate = true
        attachDoc(this, doc)

        if ((options.autofocus && !mobile) || this.hasFocus()) {
            setTimeout(function () {
                if (this$1.hasFocus() && !this$1.state.focused) {
                    onFocus(this$1)
                }
            }, 20)
        } else {
            onBlur(this)
        }

        for (var opt in optionHandlers) {
            if (optionHandlers.hasOwnProperty(opt)) {
                optionHandlers[opt](this, options[opt], Init)
            }
        }
        maybeUpdateLineNumberWidth(this)
        if (options.finishInit) {
            options.finishInit(this)
        }
        for (var i = 0; i < initHooks.length; ++i) {
            initHooks[i](this)
        }
        endOperation(this)
        // Suppress optimizelegibility in Webkit, since it breaks text
        // measuring on line wrapping boundaries.
        if (webkit && options.lineWrapping && getComputedStyle(display.lineDiv).textRendering == 'optimizelegibility') {
            display.lineDiv.style.textRendering = 'auto'
        }
    }

    // The default configuration options.
    CodeMirror.defaults = defaults
    // Functions to run when options are changed.
    CodeMirror.optionHandlers = optionHandlers

    // Attach the necessary event handlers when initializing the editor
    function registerEventHandlers(cm) {
        var d = cm.display
        on(d.scroller, 'mousedown', operation(cm, onMouseDown))
        // Older IE's will not fire a second mousedown for a double click
        if (ie && ie_version < 11) {
            on(
                d.scroller,
                'dblclick',
                operation(cm, function (e) {
                    if (signalDOMEvent(cm, e)) {
                        return
                    }
                    var pos = posFromMouse(cm, e)
                    if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) {
                        return
                    }
                    e_preventDefault(e)
                    var word = cm.findWordAt(pos)
                    extendSelection(cm.doc, word.anchor, word.head)
                })
            )
        } else {
            on(d.scroller, 'dblclick', function (e) {
                return signalDOMEvent(cm, e) || e_preventDefault(e)
            })
        }
        // Some browsers fire contextmenu *after* opening the menu, at
        // which point we can't mess with it anymore. Context menu is
        // handled in onMouseDown for these browsers.
        on(d.scroller, 'contextmenu', function (e) {
            return onContextMenu(cm, e)
        })
        on(d.input.getField(), 'contextmenu', function (e) {
            if (!d.scroller.contains(e.target)) {
                onContextMenu(cm, e)
            }
        })

        // Used to suppress mouse event handling when a touch happens
        var touchFinished,
            prevTouch = { end: 0 }
        function finishTouch() {
            if (d.activeTouch) {
                touchFinished = setTimeout(function () {
                    return (d.activeTouch = null)
                }, 1000)
                prevTouch = d.activeTouch
                prevTouch.end = +new Date()
            }
        }
        function isMouseLikeTouchEvent(e) {
            if (e.touches.length != 1) {
                return false
            }
            var touch = e.touches[0]
            return touch.radiusX <= 1 && touch.radiusY <= 1
        }
        function farAway(touch, other) {
            if (other.left == null) {
                return true
            }
            var dx = other.left - touch.left,
                dy = other.top - touch.top
            return dx * dx + dy * dy > 20 * 20
        }
        on(d.scroller, 'touchstart', function (e) {
            if (!signalDOMEvent(cm, e) && !isMouseLikeTouchEvent(e) && !clickInGutter(cm, e)) {
                d.input.ensurePolled()
                clearTimeout(touchFinished)
                var now = +new Date()
                d.activeTouch = { start: now, moved: false, prev: now - prevTouch.end <= 300 ? prevTouch : null }
                if (e.touches.length == 1) {
                    d.activeTouch.left = e.touches[0].pageX
                    d.activeTouch.top = e.touches[0].pageY
                }
            }
        })
        on(d.scroller, 'touchmove', function () {
            if (d.activeTouch) {
                d.activeTouch.moved = true
            }
        })
        on(d.scroller, 'touchend', function (e) {
            var touch = d.activeTouch
            if (touch && !eventInWidget(d, e) && touch.left != null && !touch.moved && new Date() - touch.start < 300) {
                var pos = cm.coordsChar(d.activeTouch, 'page'),
                    range
                if (!touch.prev || farAway(touch, touch.prev)) {
                    // Single tap
                    range = new Range(pos, pos)
                } else if (!touch.prev.prev || farAway(touch, touch.prev.prev)) {
                    // Double tap
                    range = cm.findWordAt(pos)
                } // Triple tap
                else {
                    range = new Range(Pos(pos.line, 0), clipPos(cm.doc, Pos(pos.line + 1, 0)))
                }
                cm.setSelection(range.anchor, range.head)
                cm.focus()
                e_preventDefault(e)
            }
            finishTouch()
        })
        on(d.scroller, 'touchcancel', finishTouch)

        // Sync scrolling between fake scrollbars and real scrollable
        // area, ensure viewport is updated when scrolling.
        on(d.scroller, 'scroll', function () {
            if (d.scroller.clientHeight) {
                updateScrollTop(cm, d.scroller.scrollTop)
                setScrollLeft(cm, d.scroller.scrollLeft, true)
                signal(cm, 'scroll', cm)
            }
        })

        // Listen to wheel events in order to try and update the viewport on time.
        on(d.scroller, 'mousewheel', function (e) {
            return onScrollWheel(cm, e)
        })
        on(d.scroller, 'DOMMouseScroll', function (e) {
            return onScrollWheel(cm, e)
        })

        // Prevent wrapper from ever scrolling
        on(d.wrapper, 'scroll', function () {
            return (d.wrapper.scrollTop = d.wrapper.scrollLeft = 0)
        })

        d.dragFunctions = {
            enter: function (e) {
                if (!signalDOMEvent(cm, e)) {
                    e_stop(e)
                }
            },
            over: function (e) {
                if (!signalDOMEvent(cm, e)) {
                    onDragOver(cm, e)
                    e_stop(e)
                }
            },
            start: function (e) {
                return onDragStart(cm, e)
            },
            drop: operation(cm, onDrop),
            leave: function (e) {
                if (!signalDOMEvent(cm, e)) {
                    clearDragCursor(cm)
                }
            },
        }

        var inp = d.input.getField()
        on(inp, 'keyup', function (e) {
            return onKeyUp.call(cm, e)
        })
        on(inp, 'keydown', operation(cm, onKeyDown))
        on(inp, 'keypress', operation(cm, onKeyPress))
        on(inp, 'focus', function (e) {
            return onFocus(cm, e)
        })
        on(inp, 'blur', function (e) {
            return onBlur(cm, e)
        })
    }

    var initHooks = []
    CodeMirror.defineInitHook = function (f) {
        return initHooks.push(f)
    }

    // Indent the given line. The how parameter can be "smart",
    // "add"/null, "subtract", or "prev". When aggressive is false
    // (typically set to true for forced single-line indents), empty
    // lines are not indented, and places where the mode returns Pass
    // are left alone.
    function indentLine(cm, n, how, aggressive) {
        var doc = cm.doc,
            state
        if (how == null) {
            how = 'add'
        }
        if (how == 'smart') {
            // Fall back to "prev" when the mode doesn't have an indentation
            // method.
            if (!doc.mode.indent) {
                how = 'prev'
            } else {
                state = getContextBefore(cm, n).state
            }
        }

        var tabSize = cm.options.tabSize
        var line = getLine(doc, n),
            curSpace = countColumn(line.text, null, tabSize)
        if (line.stateAfter) {
            line.stateAfter = null
        }
        var curSpaceString = line.text.match(/^\s*/)[0],
            indentation
        if (!aggressive && !/\S/.test(line.text)) {
            indentation = 0
            how = 'not'
        } else if (how == 'smart') {
            indentation = doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text)
            if (indentation == Pass || indentation > 150) {
                if (!aggressive) {
                    return
                }
                how = 'prev'
            }
        }
        if (how == 'prev') {
            if (n > doc.first) {
                indentation = countColumn(getLine(doc, n - 1).text, null, tabSize)
            } else {
                indentation = 0
            }
        } else if (how == 'add') {
            indentation = curSpace + cm.options.indentUnit
        } else if (how == 'subtract') {
            indentation = curSpace - cm.options.indentUnit
        } else if (typeof how == 'number') {
            indentation = curSpace + how
        }
        indentation = Math.max(0, indentation)

        var indentString = '',
            pos = 0
        if (cm.options.indentWithTabs) {
            for (var i = Math.floor(indentation / tabSize); i; --i) {
                pos += tabSize
                indentString += '\t'
            }
        }
        if (pos < indentation) {
            indentString += spaceStr(indentation - pos)
        }

        if (indentString != curSpaceString) {
            replaceRange(doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), '+input')
            line.stateAfter = null
            return true
        } else {
            // Ensure that, if the cursor was in the whitespace at the start
            // of the line, it is moved to the end of that space.
            for (var i$1 = 0; i$1 < doc.sel.ranges.length; i$1++) {
                var range = doc.sel.ranges[i$1]
                if (range.head.line == n && range.head.ch < curSpaceString.length) {
                    var pos$1 = Pos(n, curSpaceString.length)
                    replaceOneSelection(doc, i$1, new Range(pos$1, pos$1))
                    break
                }
            }
        }
    }

    // This will be set to a {lineWise: bool, text: [string]} object, so
    // that, when pasting, we know what kind of selections the copied
    // text was made out of.
    var lastCopied = null

    function setLastCopied(newLastCopied) {
        lastCopied = newLastCopied
    }

    function applyTextInput(cm, inserted, deleted, sel, origin) {
        var doc = cm.doc
        cm.display.shift = false
        if (!sel) {
            sel = doc.sel
        }

        var recent = +new Date() - 200
        var paste = origin == 'paste' || cm.state.pasteIncoming > recent
        var textLines = splitLinesAuto(inserted),
            multiPaste = null
        // When pasting N lines into N selections, insert one line per selection
        if (paste && sel.ranges.length > 1) {
            if (lastCopied && lastCopied.text.join('\n') == inserted) {
                if (sel.ranges.length % lastCopied.text.length == 0) {
                    multiPaste = []
                    for (var i = 0; i < lastCopied.text.length; i++) {
                        multiPaste.push(doc.splitLines(lastCopied.text[i]))
                    }
                }
            } else if (textLines.length == sel.ranges.length && cm.options.pasteLinesPerSelection) {
                multiPaste = map(textLines, function (l) {
                    return [l]
                })
            }
        }

        var updateInput = cm.curOp.updateInput
        // Normal behavior is to insert the new text into every selection
        for (var i$1 = sel.ranges.length - 1; i$1 >= 0; i$1--) {
            var range = sel.ranges[i$1]
            var from = range.from(),
                to = range.to()
            if (range.empty()) {
                if (deleted && deleted > 0) {
                    // Handle deletion
                    from = Pos(from.line, from.ch - deleted)
                } else if (cm.state.overwrite && !paste) {
                    // Handle overwrite
                    to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length))
                } else if (paste && lastCopied && lastCopied.lineWise && lastCopied.text.join('\n') == textLines.join('\n')) {
                    from = to = Pos(from.line, 0)
                }
            }
            var changeEvent = {
                from: from,
                to: to,
                text: multiPaste ? multiPaste[i$1 % multiPaste.length] : textLines,
                origin: origin || (paste ? 'paste' : cm.state.cutIncoming > recent ? 'cut' : '+input'),
            }
            makeChange(cm.doc, changeEvent)
            signalLater(cm, 'inputRead', cm, changeEvent)
        }
        if (inserted && !paste) {
            triggerElectric(cm, inserted)
        }

        ensureCursorVisible(cm)
        if (cm.curOp.updateInput < 2) {
            cm.curOp.updateInput = updateInput
        }
        cm.curOp.typing = true
        cm.state.pasteIncoming = cm.state.cutIncoming = -1
    }

    function handlePaste(e, cm) {
        var pasted = e.clipboardData && e.clipboardData.getData('Text')
        if (pasted) {
            e.preventDefault()
            if (!cm.isReadOnly() && !cm.options.disableInput) {
                runInOp(cm, function () {
                    return applyTextInput(cm, pasted, 0, null, 'paste')
                })
            }
            return true
        }
    }

    function triggerElectric(cm, inserted) {
        // When an 'electric' character is inserted, immediately trigger a reindent
        if (!cm.options.electricChars || !cm.options.smartIndent) {
            return
        }
        var sel = cm.doc.sel

        for (var i = sel.ranges.length - 1; i >= 0; i--) {
            var range = sel.ranges[i]
            if (range.head.ch > 100 || (i && sel.ranges[i - 1].head.line == range.head.line)) {
                continue
            }
            var mode = cm.getModeAt(range.head)
            var indented = false
            if (mode.electricChars) {
                for (var j = 0; j < mode.electricChars.length; j++) {
                    if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {
                        indented = indentLine(cm, range.head.line, 'smart')
                        break
                    }
                }
            } else if (mode.electricInput) {
                if (mode.electricInput.test(getLine(cm.doc, range.head.line).text.slice(0, range.head.ch))) {
                    indented = indentLine(cm, range.head.line, 'smart')
                }
            }
            if (indented) {
                signalLater(cm, 'electricInput', cm, range.head.line)
            }
        }
    }

    function copyableRanges(cm) {
        var text = [],
            ranges = []
        for (var i = 0; i < cm.doc.sel.ranges.length; i++) {
            var line = cm.doc.sel.ranges[i].head.line
            var lineRange = { anchor: Pos(line, 0), head: Pos(line + 1, 0) }
            ranges.push(lineRange)
            text.push(cm.getRange(lineRange.anchor, lineRange.head))
        }
        return { text: text, ranges: ranges }
    }

    function disableBrowserMagic(field, spellcheck, autocorrect, autocapitalize) {
        field.setAttribute('autocorrect', autocorrect ? '' : 'off')
        field.setAttribute('autocapitalize', autocapitalize ? '' : 'off')
        field.setAttribute('spellcheck', !!spellcheck)
    }

    function hiddenTextarea() {
        var te = elt('textarea', null, null, 'position: absolute; bottom: -1em; padding: 0; width: 1px; height: 1em; min-height: 1em; outline: none')
        var div = elt('div', [te], null, 'overflow: hidden; position: relative; width: 3px; height: 0px;')
        // The textarea is kept positioned near the cursor to prevent the
        // fact that it'll be scrolled into view on input from scrolling
        // our fake cursor out of view. On webkit, when wrap=off, paste is
        // very slow. So make the area wide instead.
        if (webkit) {
            te.style.width = '1000px'
        } else {
            te.setAttribute('wrap', 'off')
        }
        // If border: 0; -- iOS fails to open keyboard (issue #1287)
        if (ios) {
            te.style.border = '1px solid black'
        }
        disableBrowserMagic(te)
        return div
    }

    // The publicly visible API. Note that methodOp(f) means
    // 'wrap f in an operation, performed on its `this` parameter'.

    // This is not the complete set of editor methods. Most of the
    // methods defined on the Doc type are also injected into
    // CodeMirror.prototype, for backwards compatibility and
    // convenience.

    function addEditorMethods(CodeMirror) {
        var optionHandlers = CodeMirror.optionHandlers

        var helpers = (CodeMirror.helpers = {})

        CodeMirror.prototype = {
            constructor: CodeMirror,
            focus: function () {
                window.focus()
                this.display.input.focus()
            },

            setOption: function (option, value) {
                var options = this.options,
                    old = options[option]
                if (options[option] == value && option != 'mode') {
                    return
                }
                options[option] = value
                if (optionHandlers.hasOwnProperty(option)) {
                    operation(this, optionHandlers[option])(this, value, old)
                }
                signal(this, 'optionChange', this, option)
            },

            getOption: function (option) {
                return this.options[option]
            },
            getDoc: function () {
                return this.doc
            },

            addKeyMap: function (map, bottom) {
                this.state.keyMaps[bottom ? 'push' : 'unshift'](getKeyMap(map))
            },
            removeKeyMap: function (map) {
                var maps = this.state.keyMaps
                for (var i = 0; i < maps.length; ++i) {
                    if (maps[i] == map || maps[i].name == map) {
                        maps.splice(i, 1)
                        return true
                    }
                }
            },

            addOverlay: methodOp(function (spec, options) {
                var mode = spec.token ? spec : CodeMirror.getMode(this.options, spec)
                if (mode.startState) {
                    throw new Error('Overlays may not be stateful.')
                }
                insertSorted(this.state.overlays, { mode: mode, modeSpec: spec, opaque: options && options.opaque, priority: (options && options.priority) || 0 }, function (overlay) {
                    return overlay.priority
                })
                this.state.modeGen++
                regChange(this)
            }),
            removeOverlay: methodOp(function (spec) {
                var overlays = this.state.overlays
                for (var i = 0; i < overlays.length; ++i) {
                    var cur = overlays[i].modeSpec
                    if (cur == spec || (typeof spec == 'string' && cur.name == spec)) {
                        overlays.splice(i, 1)
                        this.state.modeGen++
                        regChange(this)
                        return
                    }
                }
            }),

            indentLine: methodOp(function (n, dir, aggressive) {
                if (typeof dir != 'string' && typeof dir != 'number') {
                    if (dir == null) {
                        dir = this.options.smartIndent ? 'smart' : 'prev'
                    } else {
                        dir = dir ? 'add' : 'subtract'
                    }
                }
                if (isLine(this.doc, n)) {
                    indentLine(this, n, dir, aggressive)
                }
            }),
            indentSelection: methodOp(function (how) {
                var ranges = this.doc.sel.ranges,
                    end = -1
                for (var i = 0; i < ranges.length; i++) {
                    var range = ranges[i]
                    if (!range.empty()) {
                        var from = range.from(),
                            to = range.to()
                        var start = Math.max(end, from.line)
                        end = Math.min(this.lastLine(), to.line - (to.ch ? 0 : 1)) + 1
                        for (var j = start; j < end; ++j) {
                            indentLine(this, j, how)
                        }
                        var newRanges = this.doc.sel.ranges
                        if (from.ch == 0 && ranges.length == newRanges.length && newRanges[i].from().ch > 0) {
                            replaceOneSelection(this.doc, i, new Range(from, newRanges[i].to()), sel_dontScroll)
                        }
                    } else if (range.head.line > end) {
                        indentLine(this, range.head.line, how, true)
                        end = range.head.line
                        if (i == this.doc.sel.primIndex) {
                            ensureCursorVisible(this)
                        }
                    }
                }
            }),

            // Fetch the parser token for a given character. Useful for hacks
            // that want to inspect the mode state (say, for completion).
            getTokenAt: function (pos, precise) {
                return takeToken(this, pos, precise)
            },

            getLineTokens: function (line, precise) {
                return takeToken(this, Pos(line), precise, true)
            },

            getTokenTypeAt: function (pos) {
                pos = clipPos(this.doc, pos)
                var styles = getLineStyles(this, getLine(this.doc, pos.line))
                var before = 0,
                    after = (styles.length - 1) / 2,
                    ch = pos.ch
                var type
                if (ch == 0) {
                    type = styles[2]
                } else {
                    for (;;) {
                        var mid = (before + after) >> 1
                        if ((mid ? styles[mid * 2 - 1] : 0) >= ch) {
                            after = mid
                        } else if (styles[mid * 2 + 1] < ch) {
                            before = mid + 1
                        } else {
                            type = styles[mid * 2 + 2]
                            break
                        }
                    }
                }
                var cut = type ? type.indexOf('overlay ') : -1
                return cut < 0 ? type : cut == 0 ? null : type.slice(0, cut - 1)
            },

            getModeAt: function (pos) {
                var mode = this.doc.mode
                if (!mode.innerMode) {
                    return mode
                }
                return CodeMirror.innerMode(mode, this.getTokenAt(pos).state).mode
            },

            getHelper: function (pos, type) {
                return this.getHelpers(pos, type)[0]
            },

            getHelpers: function (pos, type) {
                var found = []
                if (!helpers.hasOwnProperty(type)) {
                    return found
                }
                var help = helpers[type],
                    mode = this.getModeAt(pos)
                if (typeof mode[type] == 'string') {
                    if (help[mode[type]]) {
                        found.push(help[mode[type]])
                    }
                } else if (mode[type]) {
                    for (var i = 0; i < mode[type].length; i++) {
                        var val = help[mode[type][i]]
                        if (val) {
                            found.push(val)
                        }
                    }
                } else if (mode.helperType && help[mode.helperType]) {
                    found.push(help[mode.helperType])
                } else if (help[mode.name]) {
                    found.push(help[mode.name])
                }
                for (var i$1 = 0; i$1 < help._global.length; i$1++) {
                    var cur = help._global[i$1]
                    if (cur.pred(mode, this) && indexOf(found, cur.val) == -1) {
                        found.push(cur.val)
                    }
                }
                return found
            },

            getStateAfter: function (line, precise) {
                var doc = this.doc
                line = clipLine(doc, line == null ? doc.first + doc.size - 1 : line)
                return getContextBefore(this, line + 1, precise).state
            },

            cursorCoords: function (start, mode) {
                var pos,
                    range = this.doc.sel.primary()
                if (start == null) {
                    pos = range.head
                } else if (typeof start == 'object') {
                    pos = clipPos(this.doc, start)
                } else {
                    pos = start ? range.from() : range.to()
                }
                return cursorCoords(this, pos, mode || 'page')
            },

            charCoords: function (pos, mode) {
                return charCoords(this, clipPos(this.doc, pos), mode || 'page')
            },

            coordsChar: function (coords, mode) {
                coords = fromCoordSystem(this, coords, mode || 'page')
                return coordsChar(this, coords.left, coords.top)
            },

            lineAtHeight: function (height, mode) {
                height = fromCoordSystem(this, { top: height, left: 0 }, mode || 'page').top
                return lineAtHeight(this.doc, height + this.display.viewOffset)
            },
            heightAtLine: function (line, mode, includeWidgets) {
                var end = false,
                    lineObj
                if (typeof line == 'number') {
                    var last = this.doc.first + this.doc.size - 1
                    if (line < this.doc.first) {
                        line = this.doc.first
                    } else if (line > last) {
                        line = last
                        end = true
                    }
                    lineObj = getLine(this.doc, line)
                } else {
                    lineObj = line
                }
                return intoCoordSystem(this, lineObj, { top: 0, left: 0 }, mode || 'page', includeWidgets || end).top + (end ? this.doc.height - heightAtLine(lineObj) : 0)
            },

            defaultTextHeight: function () {
                return textHeight(this.display)
            },
            defaultCharWidth: function () {
                return charWidth(this.display)
            },

            getViewport: function () {
                return { from: this.display.viewFrom, to: this.display.viewTo }
            },

            addWidget: function (pos, node, scroll, vert, horiz) {
                var display = this.display
                pos = cursorCoords(this, clipPos(this.doc, pos))
                var top = pos.bottom,
                    left = pos.left
                node.style.position = 'absolute'
                node.setAttribute('cm-ignore-events', 'true')
                this.display.input.setUneditable(node)
                display.sizer.appendChild(node)
                if (vert == 'over') {
                    top = pos.top
                } else if (vert == 'above' || vert == 'near') {
                    var vspace = Math.max(display.wrapper.clientHeight, this.doc.height),
                        hspace = Math.max(display.sizer.clientWidth, display.lineSpace.clientWidth)
                    // Default to positioning above (if specified and possible); otherwise default to positioning below
                    if ((vert == 'above' || pos.bottom + node.offsetHeight > vspace) && pos.top > node.offsetHeight) {
                        top = pos.top - node.offsetHeight
                    } else if (pos.bottom + node.offsetHeight <= vspace) {
                        top = pos.bottom
                    }
                    if (left + node.offsetWidth > hspace) {
                        left = hspace - node.offsetWidth
                    }
                }
                node.style.top = top + 'px'
                node.style.left = node.style.right = ''
                if (horiz == 'right') {
                    left = display.sizer.clientWidth - node.offsetWidth
                    node.style.right = '0px'
                } else {
                    if (horiz == 'left') {
                        left = 0
                    } else if (horiz == 'middle') {
                        left = (display.sizer.clientWidth - node.offsetWidth) / 2
                    }
                    node.style.left = left + 'px'
                }
                if (scroll) {
                    scrollIntoView(this, { left: left, top: top, right: left + node.offsetWidth, bottom: top + node.offsetHeight })
                }
            },

            triggerOnKeyDown: methodOp(onKeyDown),
            triggerOnKeyPress: methodOp(onKeyPress),
            triggerOnKeyUp: onKeyUp,
            triggerOnMouseDown: methodOp(onMouseDown),

            execCommand: function (cmd) {
                if (commands.hasOwnProperty(cmd)) {
                    return commands[cmd].call(null, this)
                }
            },

            triggerElectric: methodOp(function (text) {
                triggerElectric(this, text)
            }),

            findPosH: function (from, amount, unit, visually) {
                var dir = 1
                if (amount < 0) {
                    dir = -1
                    amount = -amount
                }
                var cur = clipPos(this.doc, from)
                for (var i = 0; i < amount; ++i) {
                    cur = findPosH(this.doc, cur, dir, unit, visually)
                    if (cur.hitSide) {
                        break
                    }
                }
                return cur
            },

            moveH: methodOp(function (dir, unit) {
                var this$1 = this

                this.extendSelectionsBy(function (range) {
                    if (this$1.display.shift || this$1.doc.extend || range.empty()) {
                        return findPosH(this$1.doc, range.head, dir, unit, this$1.options.rtlMoveVisually)
                    } else {
                        return dir < 0 ? range.from() : range.to()
                    }
                }, sel_move)
            }),

            deleteH: methodOp(function (dir, unit) {
                var sel = this.doc.sel,
                    doc = this.doc
                if (sel.somethingSelected()) {
                    doc.replaceSelection('', null, '+delete')
                } else {
                    deleteNearSelection(this, function (range) {
                        var other = findPosH(doc, range.head, dir, unit, false)
                        return dir < 0 ? { from: other, to: range.head } : { from: range.head, to: other }
                    })
                }
            }),

            findPosV: function (from, amount, unit, goalColumn) {
                var dir = 1,
                    x = goalColumn
                if (amount < 0) {
                    dir = -1
                    amount = -amount
                }
                var cur = clipPos(this.doc, from)
                for (var i = 0; i < amount; ++i) {
                    var coords = cursorCoords(this, cur, 'div')
                    if (x == null) {
                        x = coords.left
                    } else {
                        coords.left = x
                    }
                    cur = findPosV(this, coords, dir, unit)
                    if (cur.hitSide) {
                        break
                    }
                }
                return cur
            },

            moveV: methodOp(function (dir, unit) {
                var this$1 = this

                var doc = this.doc,
                    goals = []
                var collapse = !this.display.shift && !doc.extend && doc.sel.somethingSelected()
                doc.extendSelectionsBy(function (range) {
                    if (collapse) {
                        return dir < 0 ? range.from() : range.to()
                    }
                    var headPos = cursorCoords(this$1, range.head, 'div')
                    if (range.goalColumn != null) {
                        headPos.left = range.goalColumn
                    }
                    goals.push(headPos.left)
                    var pos = findPosV(this$1, headPos, dir, unit)
                    if (unit == 'page' && range == doc.sel.primary()) {
                        addToScrollTop(this$1, charCoords(this$1, pos, 'div').top - headPos.top)
                    }
                    return pos
                }, sel_move)
                if (goals.length) {
                    for (var i = 0; i < doc.sel.ranges.length; i++) {
                        doc.sel.ranges[i].goalColumn = goals[i]
                    }
                }
            }),

            // Find the word at the given position (as returned by coordsChar).
            findWordAt: function (pos) {
                var doc = this.doc,
                    line = getLine(doc, pos.line).text
                var start = pos.ch,
                    end = pos.ch
                if (line) {
                    var helper = this.getHelper(pos, 'wordChars')
                    if ((pos.sticky == 'before' || end == line.length) && start) {
                        --start
                    } else {
                        ++end
                    }
                    var startChar = line.charAt(start)
                    var check = isWordChar(startChar, helper)
                        ? function (ch) {
                              return isWordChar(ch, helper)
                          }
                        : /\s/.test(startChar)
                        ? function (ch) {
                              return /\s/.test(ch)
                          }
                        : function (ch) {
                              return !/\s/.test(ch) && !isWordChar(ch)
                          }
                    while (start > 0 && check(line.charAt(start - 1))) {
                        --start
                    }
                    while (end < line.length && check(line.charAt(end))) {
                        ++end
                    }
                }
                return new Range(Pos(pos.line, start), Pos(pos.line, end))
            },

            toggleOverwrite: function (value) {
                if (value != null && value == this.state.overwrite) {
                    return
                }
                if ((this.state.overwrite = !this.state.overwrite)) {
                    addClass(this.display.cursorDiv, 'CodeMirror-overwrite')
                } else {
                    rmClass(this.display.cursorDiv, 'CodeMirror-overwrite')
                }

                signal(this, 'overwriteToggle', this, this.state.overwrite)
            },
            hasFocus: function () {
                return this.display.input.getField() == activeElt()
            },
            isReadOnly: function () {
                return !!(this.options.readOnly || this.doc.cantEdit)
            },

            scrollTo: methodOp(function (x, y) {
                scrollToCoords(this, x, y)
            }),
            getScrollInfo: function () {
                var scroller = this.display.scroller
                return {
                    left: scroller.scrollLeft,
                    top: scroller.scrollTop,
                    height: scroller.scrollHeight - scrollGap(this) - this.display.barHeight,
                    width: scroller.scrollWidth - scrollGap(this) - this.display.barWidth,
                    clientHeight: displayHeight(this),
                    clientWidth: displayWidth(this),
                }
            },

            scrollIntoView: methodOp(function (range, margin) {
                if (range == null) {
                    range = { from: this.doc.sel.primary().head, to: null }
                    if (margin == null) {
                        margin = this.options.cursorScrollMargin
                    }
                } else if (typeof range == 'number') {
                    range = { from: Pos(range, 0), to: null }
                } else if (range.from == null) {
                    range = { from: range, to: null }
                }
                if (!range.to) {
                    range.to = range.from
                }
                range.margin = margin || 0

                if (range.from.line != null) {
                    scrollToRange(this, range)
                } else {
                    scrollToCoordsRange(this, range.from, range.to, range.margin)
                }
            }),

            setSize: methodOp(function (width, height) {
                var this$1 = this

                var interpret = function (val) {
                    return typeof val == 'number' || /^\d+$/.test(String(val)) ? val + 'px' : val
                }
                if (width != null) {
                    this.display.wrapper.style.width = interpret(width)
                }
                if (height != null) {
                    this.display.wrapper.style.height = interpret(height)
                }
                if (this.options.lineWrapping) {
                    clearLineMeasurementCache(this)
                }
                var lineNo = this.display.viewFrom
                this.doc.iter(lineNo, this.display.viewTo, function (line) {
                    if (line.widgets) {
                        for (var i = 0; i < line.widgets.length; i++) {
                            if (line.widgets[i].noHScroll) {
                                regLineChange(this$1, lineNo, 'widget')
                                break
                            }
                        }
                    }
                    ++lineNo
                })
                this.curOp.forceUpdate = true
                signal(this, 'refresh', this)
            }),

            operation: function (f) {
                return runInOp(this, f)
            },
            startOperation: function () {
                return startOperation(this)
            },
            endOperation: function () {
                return endOperation(this)
            },

            refresh: methodOp(function () {
                var oldHeight = this.display.cachedTextHeight
                regChange(this)
                this.curOp.forceUpdate = true
                clearCaches(this)
                scrollToCoords(this, this.doc.scrollLeft, this.doc.scrollTop)
                updateGutterSpace(this.display)
                if (oldHeight == null || Math.abs(oldHeight - textHeight(this.display)) > 0.5 || this.options.lineWrapping) {
                    estimateLineHeights(this)
                }
                signal(this, 'refresh', this)
            }),

            swapDoc: methodOp(function (doc) {
                var old = this.doc
                old.cm = null
                // Cancel the current text selection if any (#5821)
                if (this.state.selectingText) {
                    this.state.selectingText()
                }
                attachDoc(this, doc)
                clearCaches(this)
                this.display.input.reset()
                scrollToCoords(this, doc.scrollLeft, doc.scrollTop)
                this.curOp.forceScroll = true
                signalLater(this, 'swapDoc', this, old)
                return old
            }),

            phrase: function (phraseText) {
                var phrases = this.options.phrases
                return phrases && Object.prototype.hasOwnProperty.call(phrases, phraseText) ? phrases[phraseText] : phraseText
            },

            getInputField: function () {
                return this.display.input.getField()
            },
            getWrapperElement: function () {
                return this.display.wrapper
            },
            getScrollerElement: function () {
                return this.display.scroller
            },
            getGutterElement: function () {
                return this.display.gutters
            },
        }
        eventMixin(CodeMirror)

        CodeMirror.registerHelper = function (type, name, value) {
            if (!helpers.hasOwnProperty(type)) {
                helpers[type] = CodeMirror[type] = { _global: [] }
            }
            helpers[type][name] = value
        }
        CodeMirror.registerGlobalHelper = function (type, name, predicate, value) {
            CodeMirror.registerHelper(type, name, value)
            helpers[type]._global.push({ pred: predicate, val: value })
        }
    }

    // Used for horizontal relative motion. Dir is -1 or 1 (left or
    // right), unit can be "codepoint", "char", "column" (like char, but
    // doesn't cross line boundaries), "word" (across next word), or
    // "group" (to the start of next group of word or
    // non-word-non-whitespace chars). The visually param controls
    // whether, in right-to-left text, direction 1 means to move towards
    // the next index in the string, or towards the character to the right
    // of the current position. The resulting position will have a
    // hitSide=true property if it reached the end of the document.
    function findPosH(doc, pos, dir, unit, visually) {
        var oldPos = pos
        var origDir = dir
        var lineObj = getLine(doc, pos.line)
        var lineDir = visually && doc.direction == 'rtl' ? -dir : dir
        function findNextLine() {
            var l = pos.line + lineDir
            if (l < doc.first || l >= doc.first + doc.size) {
                return false
            }
            pos = new Pos(l, pos.ch, pos.sticky)
            return (lineObj = getLine(doc, l))
        }
        function moveOnce(boundToLine) {
            var next
            if (unit == 'codepoint') {
                var ch = lineObj.text.charCodeAt(pos.ch + (dir > 0 ? 0 : -1))
                if (isNaN(ch)) {
                    next = null
                } else {
                    var astral = dir > 0 ? ch >= 0xd800 && ch < 0xdc00 : ch >= 0xdc00 && ch < 0xdfff
                    next = new Pos(pos.line, Math.max(0, Math.min(lineObj.text.length, pos.ch + dir * (astral ? 2 : 1))), -dir)
                }
            } else if (visually) {
                next = moveVisually(doc.cm, lineObj, pos, dir)
            } else {
                next = moveLogically(lineObj, pos, dir)
            }
            if (next == null) {
                if (!boundToLine && findNextLine()) {
                    pos = endOfLine(visually, doc.cm, lineObj, pos.line, lineDir)
                } else {
                    return false
                }
            } else {
                pos = next
            }
            return true
        }

        if (unit == 'char' || unit == 'codepoint') {
            moveOnce()
        } else if (unit == 'column') {
            moveOnce(true)
        } else if (unit == 'word' || unit == 'group') {
            var sawType = null,
                group = unit == 'group'
            var helper = doc.cm && doc.cm.getHelper(pos, 'wordChars')
            for (var first = true; ; first = false) {
                if (dir < 0 && !moveOnce(!first)) {
                    break
                }
                var cur = lineObj.text.charAt(pos.ch) || '\n'
                var type = isWordChar(cur, helper) ? 'w' : group && cur == '\n' ? 'n' : !group || /\s/.test(cur) ? null : 'p'
                if (group && !first && !type) {
                    type = 's'
                }
                if (sawType && sawType != type) {
                    if (dir < 0) {
                        dir = 1
                        moveOnce()
                        pos.sticky = 'after'
                    }
                    break
                }

                if (type) {
                    sawType = type
                }
                if (dir > 0 && !moveOnce(!first)) {
                    break
                }
            }
        }
        var result = skipAtomic(doc, pos, oldPos, origDir, true)
        if (equalCursorPos(oldPos, result)) {
            result.hitSide = true
        }
        return result
    }

    // For relative vertical movement. Dir may be -1 or 1. Unit can be
    // "page" or "line". The resulting position will have a hitSide=true
    // property if it reached the end of the document.
    function findPosV(cm, pos, dir, unit) {
        var doc = cm.doc,
            x = pos.left,
            y
        if (unit == 'page') {
            var pageSize = Math.min(cm.display.wrapper.clientHeight, window.innerHeight || document.documentElement.clientHeight)
            var moveAmount = Math.max(pageSize - 0.5 * textHeight(cm.display), 3)
            y = (dir > 0 ? pos.bottom : pos.top) + dir * moveAmount
        } else if (unit == 'line') {
            y = dir > 0 ? pos.bottom + 3 : pos.top - 3
        }
        var target
        for (;;) {
            target = coordsChar(cm, x, y)
            if (!target.outside) {
                break
            }
            if (dir < 0 ? y <= 0 : y >= doc.height) {
                target.hitSide = true
                break
            }
            y += dir * 5
        }
        return target
    }

    // CONTENTEDITABLE INPUT STYLE

    var ContentEditableInput = function (cm) {
        this.cm = cm
        this.lastAnchorNode = this.lastAnchorOffset = this.lastFocusNode = this.lastFocusOffset = null
        this.polling = new Delayed()
        this.composing = null
        this.gracePeriod = false
        this.readDOMTimeout = null
    }

    ContentEditableInput.prototype.init = function (display) {
        var this$1 = this

        var input = this,
            cm = input.cm
        var div = (input.div = display.lineDiv)
        div.contentEditable = true
        disableBrowserMagic(div, cm.options.spellcheck, cm.options.autocorrect, cm.options.autocapitalize)

        function belongsToInput(e) {
            for (var t = e.target; t; t = t.parentNode) {
                if (t == div) {
                    return true
                }
                if (/\bCodeMirror-(?:line)?widget\b/.test(t.className)) {
                    break
                }
            }
            return false
        }

        on(div, 'paste', function (e) {
            if (!belongsToInput(e) || signalDOMEvent(cm, e) || handlePaste(e, cm)) {
                return
            }
            // IE doesn't fire input events, so we schedule a read for the pasted content in this way
            if (ie_version <= 11) {
                setTimeout(
                    operation(cm, function () {
                        return this$1.updateFromDOM()
                    }),
                    20
                )
            }
        })

        on(div, 'compositionstart', function (e) {
            this$1.composing = { data: e.data, done: false }
        })
        on(div, 'compositionupdate', function (e) {
            if (!this$1.composing) {
                this$1.composing = { data: e.data, done: false }
            }
        })
        on(div, 'compositionend', function (e) {
            if (this$1.composing) {
                if (e.data != this$1.composing.data) {
                    this$1.readFromDOMSoon()
                }
                this$1.composing.done = true
            }
        })

        on(div, 'touchstart', function () {
            return input.forceCompositionEnd()
        })

        on(div, 'input', function () {
            if (!this$1.composing) {
                this$1.readFromDOMSoon()
            }
        })

        function onCopyCut(e) {
            if (!belongsToInput(e) || signalDOMEvent(cm, e)) {
                return
            }
            if (cm.somethingSelected()) {
                setLastCopied({ lineWise: false, text: cm.getSelections() })
                if (e.type == 'cut') {
                    cm.replaceSelection('', null, 'cut')
                }
            } else if (!cm.options.lineWiseCopyCut) {
                return
            } else {
                var ranges = copyableRanges(cm)
                setLastCopied({ lineWise: true, text: ranges.text })
                if (e.type == 'cut') {
                    cm.operation(function () {
                        cm.setSelections(ranges.ranges, 0, sel_dontScroll)
                        cm.replaceSelection('', null, 'cut')
                    })
                }
            }
            if (e.clipboardData) {
                e.clipboardData.clearData()
                var content = lastCopied.text.join('\n')
                // iOS exposes the clipboard API, but seems to discard content inserted into it
                e.clipboardData.setData('Text', content)
                if (e.clipboardData.getData('Text') == content) {
                    e.preventDefault()
                    return
                }
            }
            // Old-fashioned briefly-focus-a-textarea hack
            var kludge = hiddenTextarea(),
                te = kludge.firstChild
            cm.display.lineSpace.insertBefore(kludge, cm.display.lineSpace.firstChild)
            te.value = lastCopied.text.join('\n')
            var hadFocus = activeElt()
            selectInput(te)
            setTimeout(function () {
                cm.display.lineSpace.removeChild(kludge)
                hadFocus.focus()
                if (hadFocus == div) {
                    input.showPrimarySelection()
                }
            }, 50)
        }
        on(div, 'copy', onCopyCut)
        on(div, 'cut', onCopyCut)
    }

    ContentEditableInput.prototype.screenReaderLabelChanged = function (label) {
        // Label for screenreaders, accessibility
        if (label) {
            this.div.setAttribute('aria-label', label)
        } else {
            this.div.removeAttribute('aria-label')
        }
    }

    ContentEditableInput.prototype.prepareSelection = function () {
        var result = prepareSelection(this.cm, false)
        result.focus = activeElt() == this.div
        return result
    }

    ContentEditableInput.prototype.showSelection = function (info, takeFocus) {
        if (!info || !this.cm.display.view.length) {
            return
        }
        if (info.focus || takeFocus) {
            this.showPrimarySelection()
        }
        this.showMultipleSelections(info)
    }

    ContentEditableInput.prototype.getSelection = function () {
        return this.cm.display.wrapper.ownerDocument.getSelection()
    }

    ContentEditableInput.prototype.showPrimarySelection = function () {
        var sel = this.getSelection(),
            cm = this.cm,
            prim = cm.doc.sel.primary()
        var from = prim.from(),
            to = prim.to()

        if (cm.display.viewTo == cm.display.viewFrom || from.line >= cm.display.viewTo || to.line < cm.display.viewFrom) {
            sel.removeAllRanges()
            return
        }

        var curAnchor = domToPos(cm, sel.anchorNode, sel.anchorOffset)
        var curFocus = domToPos(cm, sel.focusNode, sel.focusOffset)
        if (curAnchor && !curAnchor.bad && curFocus && !curFocus.bad && cmp(minPos(curAnchor, curFocus), from) == 0 && cmp(maxPos(curAnchor, curFocus), to) == 0) {
            return
        }

        var view = cm.display.view
        var start = (from.line >= cm.display.viewFrom && posToDOM(cm, from)) || { node: view[0].measure.map[2], offset: 0 }
        var end = to.line < cm.display.viewTo && posToDOM(cm, to)
        if (!end) {
            var measure = view[view.length - 1].measure
            var map = measure.maps ? measure.maps[measure.maps.length - 1] : measure.map
            end = { node: map[map.length - 1], offset: map[map.length - 2] - map[map.length - 3] }
        }

        if (!start || !end) {
            sel.removeAllRanges()
            return
        }

        var old = sel.rangeCount && sel.getRangeAt(0),
            rng
        try {
            rng = range(start.node, start.offset, end.offset, end.node)
        } catch (e) {} // Our model of the DOM might be outdated, in which case the range we try to set can be impossible
        if (rng) {
            if (!gecko && cm.state.focused) {
                sel.collapse(start.node, start.offset)
                if (!rng.collapsed) {
                    sel.removeAllRanges()
                    sel.addRange(rng)
                }
            } else {
                sel.removeAllRanges()
                sel.addRange(rng)
            }
            if (old && sel.anchorNode == null) {
                sel.addRange(old)
            } else if (gecko) {
                this.startGracePeriod()
            }
        }
        this.rememberSelection()
    }

    ContentEditableInput.prototype.startGracePeriod = function () {
        var this$1 = this

        clearTimeout(this.gracePeriod)
        this.gracePeriod = setTimeout(function () {
            this$1.gracePeriod = false
            if (this$1.selectionChanged()) {
                this$1.cm.operation(function () {
                    return (this$1.cm.curOp.selectionChanged = true)
                })
            }
        }, 20)
    }

    ContentEditableInput.prototype.showMultipleSelections = function (info) {
        removeChildrenAndAdd(this.cm.display.cursorDiv, info.cursors)
        removeChildrenAndAdd(this.cm.display.selectionDiv, info.selection)
    }

    ContentEditableInput.prototype.rememberSelection = function () {
        var sel = this.getSelection()
        this.lastAnchorNode = sel.anchorNode
        this.lastAnchorOffset = sel.anchorOffset
        this.lastFocusNode = sel.focusNode
        this.lastFocusOffset = sel.focusOffset
    }

    ContentEditableInput.prototype.selectionInEditor = function () {
        var sel = this.getSelection()
        if (!sel.rangeCount) {
            return false
        }
        var node = sel.getRangeAt(0).commonAncestorContainer
        return contains(this.div, node)
    }

    ContentEditableInput.prototype.focus = function () {
        if (this.cm.options.readOnly != 'nocursor') {
            if (!this.selectionInEditor() || activeElt() != this.div) {
                this.showSelection(this.prepareSelection(), true)
            }
            this.div.focus()
        }
    }
    ContentEditableInput.prototype.blur = function () {
        this.div.blur()
    }
    ContentEditableInput.prototype.getField = function () {
        return this.div
    }

    ContentEditableInput.prototype.supportsTouch = function () {
        return true
    }

    ContentEditableInput.prototype.receivedFocus = function () {
        var this$1 = this

        var input = this
        if (this.selectionInEditor()) {
            setTimeout(function () {
                return this$1.pollSelection()
            }, 20)
        } else {
            runInOp(this.cm, function () {
                return (input.cm.curOp.selectionChanged = true)
            })
        }

        function poll() {
            if (input.cm.state.focused) {
                input.pollSelection()
                input.polling.set(input.cm.options.pollInterval, poll)
            }
        }
        this.polling.set(this.cm.options.pollInterval, poll)
    }

    ContentEditableInput.prototype.selectionChanged = function () {
        var sel = this.getSelection()
        return sel.anchorNode != this.lastAnchorNode || sel.anchorOffset != this.lastAnchorOffset || sel.focusNode != this.lastFocusNode || sel.focusOffset != this.lastFocusOffset
    }

    ContentEditableInput.prototype.pollSelection = function () {
        if (this.readDOMTimeout != null || this.gracePeriod || !this.selectionChanged()) {
            return
        }
        var sel = this.getSelection(),
            cm = this.cm
        // On Android Chrome (version 56, at least), backspacing into an
        // uneditable block element will put the cursor in that element,
        // and then, because it's not editable, hide the virtual keyboard.
        // Because Android doesn't allow us to actually detect backspace
        // presses in a sane way, this code checks for when that happens
        // and simulates a backspace press in this case.
        if (android && chrome && this.cm.display.gutterSpecs.length && isInGutter(sel.anchorNode)) {
            this.cm.triggerOnKeyDown({ type: 'keydown', keyCode: 8, preventDefault: Math.abs })
            this.blur()
            this.focus()
            return
        }
        if (this.composing) {
            return
        }
        this.rememberSelection()
        var anchor = domToPos(cm, sel.anchorNode, sel.anchorOffset)
        var head = domToPos(cm, sel.focusNode, sel.focusOffset)
        if (anchor && head) {
            runInOp(cm, function () {
                setSelection(cm.doc, simpleSelection(anchor, head), sel_dontScroll)
                if (anchor.bad || head.bad) {
                    cm.curOp.selectionChanged = true
                }
            })
        }
    }

    ContentEditableInput.prototype.pollContent = function () {
        if (this.readDOMTimeout != null) {
            clearTimeout(this.readDOMTimeout)
            this.readDOMTimeout = null
        }

        var cm = this.cm,
            display = cm.display,
            sel = cm.doc.sel.primary()
        var from = sel.from(),
            to = sel.to()
        if (from.ch == 0 && from.line > cm.firstLine()) {
            from = Pos(from.line - 1, getLine(cm.doc, from.line - 1).length)
        }
        if (to.ch == getLine(cm.doc, to.line).text.length && to.line < cm.lastLine()) {
            to = Pos(to.line + 1, 0)
        }
        if (from.line < display.viewFrom || to.line > display.viewTo - 1) {
            return false
        }

        var fromIndex, fromLine, fromNode
        if (from.line == display.viewFrom || (fromIndex = findViewIndex(cm, from.line)) == 0) {
            fromLine = lineNo(display.view[0].line)
            fromNode = display.view[0].node
        } else {
            fromLine = lineNo(display.view[fromIndex].line)
            fromNode = display.view[fromIndex - 1].node.nextSibling
        }
        var toIndex = findViewIndex(cm, to.line)
        var toLine, toNode
        if (toIndex == display.view.length - 1) {
            toLine = display.viewTo - 1
            toNode = display.lineDiv.lastChild
        } else {
            toLine = lineNo(display.view[toIndex + 1].line) - 1
            toNode = display.view[toIndex + 1].node.previousSibling
        }

        if (!fromNode) {
            return false
        }
        var newText = cm.doc.splitLines(domTextBetween(cm, fromNode, toNode, fromLine, toLine))
        var oldText = getBetween(cm.doc, Pos(fromLine, 0), Pos(toLine, getLine(cm.doc, toLine).text.length))
        while (newText.length > 1 && oldText.length > 1) {
            if (lst(newText) == lst(oldText)) {
                newText.pop()
                oldText.pop()
                toLine--
            } else if (newText[0] == oldText[0]) {
                newText.shift()
                oldText.shift()
                fromLine++
            } else {
                break
            }
        }

        var cutFront = 0,
            cutEnd = 0
        var newTop = newText[0],
            oldTop = oldText[0],
            maxCutFront = Math.min(newTop.length, oldTop.length)
        while (cutFront < maxCutFront && newTop.charCodeAt(cutFront) == oldTop.charCodeAt(cutFront)) {
            ++cutFront
        }
        var newBot = lst(newText),
            oldBot = lst(oldText)
        var maxCutEnd = Math.min(newBot.length - (newText.length == 1 ? cutFront : 0), oldBot.length - (oldText.length == 1 ? cutFront : 0))
        while (cutEnd < maxCutEnd && newBot.charCodeAt(newBot.length - cutEnd - 1) == oldBot.charCodeAt(oldBot.length - cutEnd - 1)) {
            ++cutEnd
        }
        // Try to move start of change to start of selection if ambiguous
        if (newText.length == 1 && oldText.length == 1 && fromLine == from.line) {
            while (cutFront && cutFront > from.ch && newBot.charCodeAt(newBot.length - cutEnd - 1) == oldBot.charCodeAt(oldBot.length - cutEnd - 1)) {
                cutFront--
                cutEnd++
            }
        }

        newText[newText.length - 1] = newBot.slice(0, newBot.length - cutEnd).replace(/^\u200b+/, '')
        newText[0] = newText[0].slice(cutFront).replace(/\u200b+$/, '')

        var chFrom = Pos(fromLine, cutFront)
        var chTo = Pos(toLine, oldText.length ? lst(oldText).length - cutEnd : 0)
        if (newText.length > 1 || newText[0] || cmp(chFrom, chTo)) {
            replaceRange(cm.doc, newText, chFrom, chTo, '+input')
            return true
        }
    }

    ContentEditableInput.prototype.ensurePolled = function () {
        this.forceCompositionEnd()
    }
    ContentEditableInput.prototype.reset = function () {
        this.forceCompositionEnd()
    }
    ContentEditableInput.prototype.forceCompositionEnd = function () {
        if (!this.composing) {
            return
        }
        clearTimeout(this.readDOMTimeout)
        this.composing = null
        this.updateFromDOM()
        this.div.blur()
        this.div.focus()
    }
    ContentEditableInput.prototype.readFromDOMSoon = function () {
        var this$1 = this

        if (this.readDOMTimeout != null) {
            return
        }
        this.readDOMTimeout = setTimeout(function () {
            this$1.readDOMTimeout = null
            if (this$1.composing) {
                if (this$1.composing.done) {
                    this$1.composing = null
                } else {
                    return
                }
            }
            this$1.updateFromDOM()
        }, 80)
    }

    ContentEditableInput.prototype.updateFromDOM = function () {
        var this$1 = this

        if (this.cm.isReadOnly() || !this.pollContent()) {
            runInOp(this.cm, function () {
                return regChange(this$1.cm)
            })
        }
    }

    ContentEditableInput.prototype.setUneditable = function (node) {
        node.contentEditable = 'false'
    }

    ContentEditableInput.prototype.onKeyPress = function (e) {
        if (e.charCode == 0 || this.composing) {
            return
        }
        e.preventDefault()
        if (!this.cm.isReadOnly()) {
            operation(this.cm, applyTextInput)(this.cm, String.fromCharCode(e.charCode == null ? e.keyCode : e.charCode), 0)
        }
    }

    ContentEditableInput.prototype.readOnlyChanged = function (val) {
        this.div.contentEditable = String(val != 'nocursor')
    }

    ContentEditableInput.prototype.onContextMenu = function () {}
    ContentEditableInput.prototype.resetPosition = function () {}

    ContentEditableInput.prototype.needsContentAttribute = true

    function posToDOM(cm, pos) {
        var view = findViewForLine(cm, pos.line)
        if (!view || view.hidden) {
            return null
        }
        var line = getLine(cm.doc, pos.line)
        var info = mapFromLineView(view, line, pos.line)

        var order = getOrder(line, cm.doc.direction),
            side = 'left'
        if (order) {
            var partPos = getBidiPartAt(order, pos.ch)
            side = partPos % 2 ? 'right' : 'left'
        }
        var result = nodeAndOffsetInLineMap(info.map, pos.ch, side)
        result.offset = result.collapse == 'right' ? result.end : result.start
        return result
    }

    function isInGutter(node) {
        for (var scan = node; scan; scan = scan.parentNode) {
            if (/CodeMirror-gutter-wrapper/.test(scan.className)) {
                return true
            }
        }
        return false
    }

    function badPos(pos, bad) {
        if (bad) {
            pos.bad = true
        }
        return pos
    }

    function domTextBetween(cm, from, to, fromLine, toLine) {
        var text = '',
            closing = false,
            lineSep = cm.doc.lineSeparator(),
            extraLinebreak = false
        function recognizeMarker(id) {
            return function (marker) {
                return marker.id == id
            }
        }
        function close() {
            if (closing) {
                text += lineSep
                if (extraLinebreak) {
                    text += lineSep
                }
                closing = extraLinebreak = false
            }
        }
        function addText(str) {
            if (str) {
                close()
                text += str
            }
        }
        function walk(node) {
            if (node.nodeType == 1) {
                var cmText = node.getAttribute('cm-text')
                if (cmText) {
                    addText(cmText)
                    return
                }
                var markerID = node.getAttribute('cm-marker'),
                    range
                if (markerID) {
                    var found = cm.findMarks(Pos(fromLine, 0), Pos(toLine + 1, 0), recognizeMarker(+markerID))
                    if (found.length && (range = found[0].find(0))) {
                        addText(getBetween(cm.doc, range.from, range.to).join(lineSep))
                    }
                    return
                }
                if (node.getAttribute('contenteditable') == 'false') {
                    return
                }
                var isBlock = /^(pre|div|p|li|table|br)$/i.test(node.nodeName)
                if (!/^br$/i.test(node.nodeName) && node.textContent.length == 0) {
                    return
                }

                if (isBlock) {
                    close()
                }
                for (var i = 0; i < node.childNodes.length; i++) {
                    walk(node.childNodes[i])
                }

                if (/^(pre|p)$/i.test(node.nodeName)) {
                    extraLinebreak = true
                }
                if (isBlock) {
                    closing = true
                }
            } else if (node.nodeType == 3) {
                addText(node.nodeValue.replace(/\u200b/g, '').replace(/\u00a0/g, ' '))
            }
        }
        for (;;) {
            walk(from)
            if (from == to) {
                break
            }
            from = from.nextSibling
            extraLinebreak = false
        }
        return text
    }

    function domToPos(cm, node, offset) {
        var lineNode
        if (node == cm.display.lineDiv) {
            lineNode = cm.display.lineDiv.childNodes[offset]
            if (!lineNode) {
                return badPos(cm.clipPos(Pos(cm.display.viewTo - 1)), true)
            }
            node = null
            offset = 0
        } else {
            for (lineNode = node; ; lineNode = lineNode.parentNode) {
                if (!lineNode || lineNode == cm.display.lineDiv) {
                    return null
                }
                if (lineNode.parentNode && lineNode.parentNode == cm.display.lineDiv) {
                    break
                }
            }
        }
        for (var i = 0; i < cm.display.view.length; i++) {
            var lineView = cm.display.view[i]
            if (lineView.node == lineNode) {
                return locateNodeInLineView(lineView, node, offset)
            }
        }
    }

    function locateNodeInLineView(lineView, node, offset) {
        var wrapper = lineView.text.firstChild,
            bad = false
        if (!node || !contains(wrapper, node)) {
            return badPos(Pos(lineNo(lineView.line), 0), true)
        }
        if (node == wrapper) {
            bad = true
            node = wrapper.childNodes[offset]
            offset = 0
            if (!node) {
                var line = lineView.rest ? lst(lineView.rest) : lineView.line
                return badPos(Pos(lineNo(line), line.text.length), bad)
            }
        }

        var textNode = node.nodeType == 3 ? node : null,
            topNode = node
        if (!textNode && node.childNodes.length == 1 && node.firstChild.nodeType == 3) {
            textNode = node.firstChild
            if (offset) {
                offset = textNode.nodeValue.length
            }
        }
        while (topNode.parentNode != wrapper) {
            topNode = topNode.parentNode
        }
        var measure = lineView.measure,
            maps = measure.maps

        function find(textNode, topNode, offset) {
            for (var i = -1; i < (maps ? maps.length : 0); i++) {
                var map = i < 0 ? measure.map : maps[i]
                for (var j = 0; j < map.length; j += 3) {
                    var curNode = map[j + 2]
                    if (curNode == textNode || curNode == topNode) {
                        var line = lineNo(i < 0 ? lineView.line : lineView.rest[i])
                        var ch = map[j] + offset
                        if (offset < 0 || curNode != textNode) {
                            ch = map[j + (offset ? 1 : 0)]
                        }
                        return Pos(line, ch)
                    }
                }
            }
        }
        var found = find(textNode, topNode, offset)
        if (found) {
            return badPos(found, bad)
        }

        // FIXME this is all really shaky. might handle the few cases it needs to handle, but likely to cause problems
        for (var after = topNode.nextSibling, dist = textNode ? textNode.nodeValue.length - offset : 0; after; after = after.nextSibling) {
            found = find(after, after.firstChild, 0)
            if (found) {
                return badPos(Pos(found.line, found.ch - dist), bad)
            } else {
                dist += after.textContent.length
            }
        }
        for (var before = topNode.previousSibling, dist$1 = offset; before; before = before.previousSibling) {
            found = find(before, before.firstChild, -1)
            if (found) {
                return badPos(Pos(found.line, found.ch + dist$1), bad)
            } else {
                dist$1 += before.textContent.length
            }
        }
    }

    // TEXTAREA INPUT STYLE

    var TextareaInput = function (cm) {
        this.cm = cm
        // See input.poll and input.reset
        this.prevInput = ''

        // Flag that indicates whether we expect input to appear real soon
        // now (after some event like 'keypress' or 'input') and are
        // polling intensively.
        this.pollingFast = false
        // Self-resetting timeout for the poller
        this.polling = new Delayed()
        // Used to work around IE issue with selection being forgotten when focus moves away from textarea
        this.hasSelection = false
        this.composing = null
    }

    TextareaInput.prototype.init = function (display) {
        var this$1 = this

        var input = this,
            cm = this.cm
        this.createField(display)
        var te = this.textarea

        display.wrapper.insertBefore(this.wrapper, display.wrapper.firstChild)

        // Needed to hide big blue blinking cursor on Mobile Safari (doesn't seem to work in iOS 8 anymore)
        if (ios) {
            te.style.width = '0px'
        }

        on(te, 'input', function () {
            if (ie && ie_version >= 9 && this$1.hasSelection) {
                this$1.hasSelection = null
            }
            input.poll()
        })

        on(te, 'paste', function (e) {
            if (signalDOMEvent(cm, e) || handlePaste(e, cm)) {
                return
            }

            cm.state.pasteIncoming = +new Date()
            input.fastPoll()
        })

        function prepareCopyCut(e) {
            if (signalDOMEvent(cm, e)) {
                return
            }
            if (cm.somethingSelected()) {
                setLastCopied({ lineWise: false, text: cm.getSelections() })
            } else if (!cm.options.lineWiseCopyCut) {
                return
            } else {
                var ranges = copyableRanges(cm)
                setLastCopied({ lineWise: true, text: ranges.text })
                if (e.type == 'cut') {
                    cm.setSelections(ranges.ranges, null, sel_dontScroll)
                } else {
                    input.prevInput = ''
                    te.value = ranges.text.join('\n')
                    selectInput(te)
                }
            }
            if (e.type == 'cut') {
                cm.state.cutIncoming = +new Date()
            }
        }
        on(te, 'cut', prepareCopyCut)
        on(te, 'copy', prepareCopyCut)

        on(display.scroller, 'paste', function (e) {
            if (eventInWidget(display, e) || signalDOMEvent(cm, e)) {
                return
            }
            if (!te.dispatchEvent) {
                cm.state.pasteIncoming = +new Date()
                input.focus()
                return
            }

            // Pass the `paste` event to the textarea so it's handled by its event listener.
            var event = new Event('paste')
            event.clipboardData = e.clipboardData
            te.dispatchEvent(event)
        })

        // Prevent normal selection in the editor (we handle our own)
        on(display.lineSpace, 'selectstart', function (e) {
            if (!eventInWidget(display, e)) {
                e_preventDefault(e)
            }
        })

        on(te, 'compositionstart', function () {
            var start = cm.getCursor('from')
            if (input.composing) {
                input.composing.range.clear()
            }
            input.composing = {
                start: start,
                range: cm.markText(start, cm.getCursor('to'), { className: 'CodeMirror-composing' }),
            }
        })
        on(te, 'compositionend', function () {
            if (input.composing) {
                input.poll()
                input.composing.range.clear()
                input.composing = null
            }
        })
    }

    TextareaInput.prototype.createField = function (_display) {
        // Wraps and hides input textarea
        this.wrapper = hiddenTextarea()
        // The semihidden textarea that is focused when the editor is
        // focused, and receives input.
        this.textarea = this.wrapper.firstChild
    }

    TextareaInput.prototype.screenReaderLabelChanged = function (label) {
        // Label for screenreaders, accessibility
        if (label) {
            this.textarea.setAttribute('aria-label', label)
        } else {
            this.textarea.removeAttribute('aria-label')
        }
    }

    TextareaInput.prototype.prepareSelection = function () {
        // Redraw the selection and/or cursor
        var cm = this.cm,
            display = cm.display,
            doc = cm.doc
        var result = prepareSelection(cm)

        // Move the hidden textarea near the cursor to prevent scrolling artifacts
        if (cm.options.moveInputWithCursor) {
            var headPos = cursorCoords(cm, doc.sel.primary().head, 'div')
            var wrapOff = display.wrapper.getBoundingClientRect(),
                lineOff = display.lineDiv.getBoundingClientRect()
            result.teTop = Math.max(0, Math.min(display.wrapper.clientHeight - 10, headPos.top + lineOff.top - wrapOff.top))
            result.teLeft = Math.max(0, Math.min(display.wrapper.clientWidth - 10, headPos.left + lineOff.left - wrapOff.left))
        }

        return result
    }

    TextareaInput.prototype.showSelection = function (drawn) {
        var cm = this.cm,
            display = cm.display
        removeChildrenAndAdd(display.cursorDiv, drawn.cursors)
        removeChildrenAndAdd(display.selectionDiv, drawn.selection)
        if (drawn.teTop != null) {
            this.wrapper.style.top = drawn.teTop + 'px'
            this.wrapper.style.left = drawn.teLeft + 'px'
        }
    }

    // Reset the input to correspond to the selection (or to be empty,
    // when not typing and nothing is selected)
    TextareaInput.prototype.reset = function (typing) {
        if (this.contextMenuPending || this.composing) {
            return
        }
        var cm = this.cm
        if (cm.somethingSelected()) {
            this.prevInput = ''
            var content = cm.getSelection()
            this.textarea.value = content
            if (cm.state.focused) {
                selectInput(this.textarea)
            }
            if (ie && ie_version >= 9) {
                this.hasSelection = content
            }
        } else if (!typing) {
            this.prevInput = this.textarea.value = ''
            if (ie && ie_version >= 9) {
                this.hasSelection = null
            }
        }
    }

    TextareaInput.prototype.getField = function () {
        return this.textarea
    }

    TextareaInput.prototype.supportsTouch = function () {
        return false
    }

    TextareaInput.prototype.focus = function () {
        if (this.cm.options.readOnly != 'nocursor' && (!mobile || activeElt() != this.textarea)) {
            try {
                this.textarea.focus()
            } catch (e) {} // IE8 will throw if the textarea is display: none or not in DOM
        }
    }

    TextareaInput.prototype.blur = function () {
        this.textarea.blur()
    }

    TextareaInput.prototype.resetPosition = function () {
        this.wrapper.style.top = this.wrapper.style.left = 0
    }

    TextareaInput.prototype.receivedFocus = function () {
        this.slowPoll()
    }

    // Poll for input changes, using the normal rate of polling. This
    // runs as long as the editor is focused.
    TextareaInput.prototype.slowPoll = function () {
        var this$1 = this

        if (this.pollingFast) {
            return
        }
        this.polling.set(this.cm.options.pollInterval, function () {
            this$1.poll()
            if (this$1.cm.state.focused) {
                this$1.slowPoll()
            }
        })
    }

    // When an event has just come in that is likely to add or change
    // something in the input textarea, we poll faster, to ensure that
    // the change appears on the screen quickly.
    TextareaInput.prototype.fastPoll = function () {
        var missed = false,
            input = this
        input.pollingFast = true
        function p() {
            var changed = input.poll()
            if (!changed && !missed) {
                missed = true
                input.polling.set(60, p)
            } else {
                input.pollingFast = false
                input.slowPoll()
            }
        }
        input.polling.set(20, p)
    }

    // Read input from the textarea, and update the document to match.
    // When something is selected, it is present in the textarea, and
    // selected (unless it is huge, in which case a placeholder is
    // used). When nothing is selected, the cursor sits after previously
    // seen text (can be empty), which is stored in prevInput (we must
    // not reset the textarea when typing, because that breaks IME).
    TextareaInput.prototype.poll = function () {
        var this$1 = this

        var cm = this.cm,
            input = this.textarea,
            prevInput = this.prevInput
        // Since this is called a *lot*, try to bail out as cheaply as
        // possible when it is clear that nothing happened. hasSelection
        // will be the case when there is a lot of text in the textarea,
        // in which case reading its value would be expensive.
        if (this.contextMenuPending || !cm.state.focused || (hasSelection(input) && !prevInput && !this.composing) || cm.isReadOnly() || cm.options.disableInput || cm.state.keySeq) {
            return false
        }

        var text = input.value
        // If nothing changed, bail.
        if (text == prevInput && !cm.somethingSelected()) {
            return false
        }
        // Work around nonsensical selection resetting in IE9/10, and
        // inexplicable appearance of private area unicode characters on
        // some key combos in Mac (#2689).
        if ((ie && ie_version >= 9 && this.hasSelection === text) || (mac && /[\uf700-\uf7ff]/.test(text))) {
            cm.display.input.reset()
            return false
        }

        if (cm.doc.sel == cm.display.selForContextMenu) {
            var first = text.charCodeAt(0)
            if (first == 0x200b && !prevInput) {
                prevInput = '\u200b'
            }
            if (first == 0x21da) {
                this.reset()
                return this.cm.execCommand('undo')
            }
        }
        // Find the part of the input that is actually new
        var same = 0,
            l = Math.min(prevInput.length, text.length)
        while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) {
            ++same
        }

        runInOp(cm, function () {
            applyTextInput(cm, text.slice(same), prevInput.length - same, null, this$1.composing ? '*compose' : null)

            // Don't leave long text in the textarea, since it makes further polling slow
            if (text.length > 1000 || text.indexOf('\n') > -1) {
                input.value = this$1.prevInput = ''
            } else {
                this$1.prevInput = text
            }

            if (this$1.composing) {
                this$1.composing.range.clear()
                this$1.composing.range = cm.markText(this$1.composing.start, cm.getCursor('to'), { className: 'CodeMirror-composing' })
            }
        })
        return true
    }

    TextareaInput.prototype.ensurePolled = function () {
        if (this.pollingFast && this.poll()) {
            this.pollingFast = false
        }
    }

    TextareaInput.prototype.onKeyPress = function () {
        if (ie && ie_version >= 9) {
            this.hasSelection = null
        }
        this.fastPoll()
    }

    TextareaInput.prototype.onContextMenu = function (e) {
        var input = this,
            cm = input.cm,
            display = cm.display,
            te = input.textarea
        if (input.contextMenuPending) {
            input.contextMenuPending()
        }
        var pos = posFromMouse(cm, e),
            scrollPos = display.scroller.scrollTop
        if (!pos || presto) {
            return
        } // Opera is difficult.

        // Reset the current text selection only if the click is done outside of the selection
        // and 'resetSelectionOnContextMenu' option is true.
        var reset = cm.options.resetSelectionOnContextMenu
        if (reset && cm.doc.sel.contains(pos) == -1) {
            operation(cm, setSelection)(cm.doc, simpleSelection(pos), sel_dontScroll)
        }

        var oldCSS = te.style.cssText,
            oldWrapperCSS = input.wrapper.style.cssText
        var wrapperBox = input.wrapper.offsetParent.getBoundingClientRect()
        input.wrapper.style.cssText = 'position: static'
        te.style.cssText =
            'position: absolute; width: 30px; height: 30px;\n      top: ' +
            (e.clientY - wrapperBox.top - 5) +
            'px; left: ' +
            (e.clientX - wrapperBox.left - 5) +
            'px;\n      z-index: 1000; background: ' +
            (ie ? 'rgba(255, 255, 255, .05)' : 'transparent') +
            ';\n      outline: none; border-width: 0; outline: none; overflow: hidden; opacity: .05; filter: alpha(opacity=5);'
        var oldScrollY
        if (webkit) {
            oldScrollY = window.scrollY
        } // Work around Chrome issue (#2712)
        display.input.focus()
        if (webkit) {
            window.scrollTo(null, oldScrollY)
        }
        display.input.reset()
        // Adds "Select all" to context menu in FF
        if (!cm.somethingSelected()) {
            te.value = input.prevInput = ' '
        }
        input.contextMenuPending = rehide
        display.selForContextMenu = cm.doc.sel
        clearTimeout(display.detectingSelectAll)

        // Select-all will be greyed out if there's nothing to select, so
        // this adds a zero-width space so that we can later check whether
        // it got selected.
        function prepareSelectAllHack() {
            if (te.selectionStart != null) {
                var selected = cm.somethingSelected()
                var extval = '\u200b' + (selected ? te.value : '')
                te.value = '\u21da' // Used to catch context-menu undo
                te.value = extval
                input.prevInput = selected ? '' : '\u200b'
                te.selectionStart = 1
                te.selectionEnd = extval.length
                // Re-set this, in case some other handler touched the
                // selection in the meantime.
                display.selForContextMenu = cm.doc.sel
            }
        }
        function rehide() {
            if (input.contextMenuPending != rehide) {
                return
            }
            input.contextMenuPending = false
            input.wrapper.style.cssText = oldWrapperCSS
            te.style.cssText = oldCSS
            if (ie && ie_version < 9) {
                display.scrollbars.setScrollTop((display.scroller.scrollTop = scrollPos))
            }

            // Try to detect the user choosing select-all
            if (te.selectionStart != null) {
                if (!ie || (ie && ie_version < 9)) {
                    prepareSelectAllHack()
                }
                var i = 0,
                    poll = function () {
                        if (display.selForContextMenu == cm.doc.sel && te.selectionStart == 0 && te.selectionEnd > 0 && input.prevInput == '\u200b') {
                            operation(cm, selectAll)(cm)
                        } else if (i++ < 10) {
                            display.detectingSelectAll = setTimeout(poll, 500)
                        } else {
                            display.selForContextMenu = null
                            display.input.reset()
                        }
                    }
                display.detectingSelectAll = setTimeout(poll, 200)
            }
        }

        if (ie && ie_version >= 9) {
            prepareSelectAllHack()
        }
        if (captureRightClick) {
            e_stop(e)
            var mouseup = function () {
                off(window, 'mouseup', mouseup)
                setTimeout(rehide, 20)
            }
            on(window, 'mouseup', mouseup)
        } else {
            setTimeout(rehide, 50)
        }
    }

    TextareaInput.prototype.readOnlyChanged = function (val) {
        if (!val) {
            this.reset()
        }
        this.textarea.disabled = val == 'nocursor'
        this.textarea.readOnly = !!val
    }

    TextareaInput.prototype.setUneditable = function () {}

    TextareaInput.prototype.needsContentAttribute = false

    function fromTextArea(textarea, options) {
        options = options ? copyObj(options) : {}
        options.value = textarea.value
        if (!options.tabindex && textarea.tabIndex) {
            options.tabindex = textarea.tabIndex
        }
        if (!options.placeholder && textarea.placeholder) {
            options.placeholder = textarea.placeholder
        }
        // Set autofocus to true if this textarea is focused, or if it has
        // autofocus and no other element is focused.
        if (options.autofocus == null) {
            var hasFocus = activeElt()
            options.autofocus = hasFocus == textarea || (textarea.getAttribute('autofocus') != null && hasFocus == document.body)
        }

        function save() {
            textarea.value = cm.getValue()
        }

        var realSubmit
        if (textarea.form) {
            on(textarea.form, 'submit', save)
            // Deplorable hack to make the submit method do the right thing.
            if (!options.leaveSubmitMethodAlone) {
                var form = textarea.form
                realSubmit = form.submit
                try {
                    var wrappedSubmit = (form.submit = function () {
                        save()
                        form.submit = realSubmit
                        form.submit()
                        form.submit = wrappedSubmit
                    })
                } catch (e) {}
            }
        }

        options.finishInit = function (cm) {
            cm.save = save
            cm.getTextArea = function () {
                return textarea
            }
            cm.toTextArea = function () {
                cm.toTextArea = isNaN // Prevent this from being ran twice
                save()
                textarea.parentNode.removeChild(cm.getWrapperElement())
                textarea.style.display = ''
                if (textarea.form) {
                    off(textarea.form, 'submit', save)
                    if (!options.leaveSubmitMethodAlone && typeof textarea.form.submit == 'function') {
                        textarea.form.submit = realSubmit
                    }
                }
            }
        }

        textarea.style.display = 'none'
        var cm = CodeMirror(function (node) {
            return textarea.parentNode.insertBefore(node, textarea.nextSibling)
        }, options)
        return cm
    }

    function addLegacyProps(CodeMirror) {
        CodeMirror.off = off
        CodeMirror.on = on
        CodeMirror.wheelEventPixels = wheelEventPixels
        CodeMirror.Doc = Doc
        CodeMirror.splitLines = splitLinesAuto
        CodeMirror.countColumn = countColumn
        CodeMirror.findColumn = findColumn
        CodeMirror.isWordChar = isWordCharBasic
        CodeMirror.Pass = Pass
        CodeMirror.signal = signal
        CodeMirror.Line = Line
        CodeMirror.changeEnd = changeEnd
        CodeMirror.scrollbarModel = scrollbarModel
        CodeMirror.Pos = Pos
        CodeMirror.cmpPos = cmp
        CodeMirror.modes = modes
        CodeMirror.mimeModes = mimeModes
        CodeMirror.resolveMode = resolveMode
        CodeMirror.getMode = getMode
        CodeMirror.modeExtensions = modeExtensions
        CodeMirror.extendMode = extendMode
        CodeMirror.copyState = copyState
        CodeMirror.startState = startState
        CodeMirror.innerMode = innerMode
        CodeMirror.commands = commands
        CodeMirror.keyMap = keyMap
        CodeMirror.keyName = keyName
        CodeMirror.isModifierKey = isModifierKey
        CodeMirror.lookupKey = lookupKey
        CodeMirror.normalizeKeyMap = normalizeKeyMap
        CodeMirror.StringStream = StringStream
        CodeMirror.SharedTextMarker = SharedTextMarker
        CodeMirror.TextMarker = TextMarker
        CodeMirror.LineWidget = LineWidget
        CodeMirror.e_preventDefault = e_preventDefault
        CodeMirror.e_stopPropagation = e_stopPropagation
        CodeMirror.e_stop = e_stop
        CodeMirror.addClass = addClass
        CodeMirror.contains = contains
        CodeMirror.rmClass = rmClass
        CodeMirror.keyNames = keyNames
    }

    // EDITOR CONSTRUCTOR

    defineOptions(CodeMirror)

    addEditorMethods(CodeMirror)

    // Set up methods on CodeMirror's prototype to redirect to the editor's document.
    var dontDelegate = 'iter insert remove copy getEditor constructor'.split(' ')
    for (var prop in Doc.prototype) {
        if (Doc.prototype.hasOwnProperty(prop) && indexOf(dontDelegate, prop) < 0) {
            CodeMirror.prototype[prop] = (function (method) {
                return function () {
                    return method.apply(this.doc, arguments)
                }
            })(Doc.prototype[prop])
        }
    }

    eventMixin(Doc)
    CodeMirror.inputStyles = { textarea: TextareaInput, contenteditable: ContentEditableInput }

    // Extra arguments are stored as the mode's dependencies, which is
    // used by (legacy) mechanisms like loadmode.js to automatically
    // load a mode. (Preferred mechanism is the require/define calls.)
    CodeMirror.defineMode = function (name /*, mode, …*/) {
        if (!CodeMirror.defaults.mode && name != 'null') {
            CodeMirror.defaults.mode = name
        }
        defineMode.apply(this, arguments)
    }

    CodeMirror.defineMIME = defineMIME

    // Minimal default mode.
    CodeMirror.defineMode('null', function () {
        return {
            token: function (stream) {
                return stream.skipToEnd()
            },
        }
    })
    CodeMirror.defineMIME('text/plain', 'null')

    // EXTENSIONS

    CodeMirror.defineExtension = function (name, func) {
        CodeMirror.prototype[name] = func
    }
    CodeMirror.defineDocExtension = function (name, func) {
        Doc.prototype[name] = func
    }

    CodeMirror.fromTextArea = fromTextArea

    addLegacyProps(CodeMirror)

    CodeMirror.version = '5.65.2'

    return CodeMirror
})