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define(function (require, exports, module) {
    "use strict";

    var config = require("./config");
// tokenizing lines longer than this makes editor very slow
    var MAX_TOKEN_COUNT = 2000;
    /**
     * This class takes a set of highlighting rules, and creates a tokenizer out of them. For more information, see [the wiki on extending highlighters](https://github.com/ajaxorg/ace/wiki/Creating-or-Extending-an-Edit-Mode#wiki-extendingTheHighlighter).
     * @class Tokenizer
     **/

    /**
     * Constructs a new tokenizer based on the given rules and flags.
     * @param {Object} rules The highlighting rules
     *
     * @constructor
     **/
    var Tokenizer = function (rules) {
        this.states = rules;

        this.regExps = {};
        this.matchMappings = {};
        for (var key in this.states) {
            var state = this.states[key];
            var ruleRegExps = [];
            var matchTotal = 0;
            var mapping = this.matchMappings[key] = {defaultToken: "text"};
            var flag = "g";

            var splitterRurles = [];
            for (var i = 0; i < state.length; i++) {
                var rule = state[i];
                if (rule.defaultToken)
                    mapping.defaultToken = rule.defaultToken;
                if (rule.caseInsensitive)
                    flag = "gi";
                if (rule.regex == null)
                    continue;

                if (rule.regex instanceof RegExp)
                    rule.regex = rule.regex.toString().slice(1, -1);

                // Count number of matching groups. 2 extra groups from the full match
                // And the catch-all on the end (used to force a match);
                var adjustedregex = rule.regex;
                var matchcount = new RegExp("(?:(" + adjustedregex + ")|(.))").exec("a").length - 2;
                if (Array.isArray(rule.token)) {
                    if (rule.token.length == 1 || matchcount == 1) {
                        rule.token = rule.token[0];
                    } else if (matchcount - 1 != rule.token.length) {
                        this.reportError("number of classes and regexp groups doesn't match", {
                            rule: rule,
                            groupCount: matchcount - 1
                        });
                        rule.token = rule.token[0];
                    } else {
                        rule.tokenArray = rule.token;
                        rule.token = null;
                        rule.onMatch = this.$arrayTokens;
                    }
                } else if (typeof rule.token == "function" && !rule.onMatch) {
                    if (matchcount > 1)
                        rule.onMatch = this.$applyToken;
                    else
                        rule.onMatch = rule.token;
                }

                if (matchcount > 1) {
                    if (/\\\d/.test(rule.regex)) {
                        // Replace any backreferences and offset appropriately.
                        adjustedregex = rule.regex.replace(/\\([0-9]+)/g, function (match, digit) {
                            return "\\" + (parseInt(digit, 10) + matchTotal + 1);
                        });
                    } else {
                        matchcount = 1;
                        adjustedregex = this.removeCapturingGroups(rule.regex);
                    }
                    if (!rule.splitRegex && typeof rule.token != "string")
                        splitterRurles.push(rule); // flag will be known only at the very end
                }

                mapping[matchTotal] = i;
                matchTotal += matchcount;

                ruleRegExps.push(adjustedregex);

                // makes property access faster
                if (!rule.onMatch)
                    rule.onMatch = null;
            }

            if (!ruleRegExps.length) {
                mapping[0] = 0;
                ruleRegExps.push("$");
            }

            splitterRurles.forEach(function (rule) {
                rule.splitRegex = this.createSplitterRegexp(rule.regex, flag);
            }, this);

            this.regExps[key] = new RegExp("(" + ruleRegExps.join(")|(") + ")|($)", flag);
        }
    };

    (function () {
        this.$setMaxTokenCount = function (m) {
            MAX_TOKEN_COUNT = m | 0;
        };

        this.$applyToken = function (str) {
            var values = this.splitRegex.exec(str).slice(1);
            var types = this.token.apply(this, values);

            // required for compatibility with old modes
            if (typeof types === "string")
                return [{type: types, value: str}];

            var tokens = [];
            for (var i = 0, l = types.length; i < l; i++) {
                if (values[i])
                    tokens[tokens.length] = {
                        type: types[i],
                        value: values[i]
                    };
            }
            return tokens;
        };

        this.$arrayTokens = function (str) {
            if (!str)
                return [];
            var values = this.splitRegex.exec(str);
            if (!values)
                return "text";
            var tokens = [];
            var types = this.tokenArray;
            for (var i = 0, l = types.length; i < l; i++) {
                if (values[i + 1])
                    tokens[tokens.length] = {
                        type: types[i],
                        value: values[i + 1]
                    };
            }
            return tokens;
        };

        this.removeCapturingGroups = function (src) {
            var r = src.replace(
                /\[(?:\\.|[^\]])*?\]|\\.|\(\?[:=!]|(\()/g,
                function (x, y) {
                    return y ? "(?:" : x;
                }
            );
            return r;
        };

        this.createSplitterRegexp = function (src, flag) {
            if (src.indexOf("(?=") != -1) {
                var stack = 0;
                var inChClass = false;
                var lastCapture = {};
                src.replace(/(\\.)|(\((?:\?[=!])?)|(\))|([\[\]])/g, function (m, esc, parenOpen, parenClose, square, index) {
                    if (inChClass) {
                        inChClass = square != "]";
                    } else if (square) {
                        inChClass = true;
                    } else if (parenClose) {
                        if (stack == lastCapture.stack) {
                            lastCapture.end = index + 1;
                            lastCapture.stack = -1;
                        }
                        stack--;
                    } else if (parenOpen) {
                        stack++;
                        if (parenOpen.length != 1) {
                            lastCapture.stack = stack
                            lastCapture.start = index;
                        }
                    }
                    return m;
                });

                if (lastCapture.end != null && /^\)*$/.test(src.substr(lastCapture.end)))
                    src = src.substring(0, lastCapture.start) + src.substr(lastCapture.end);
            }

            // this is needed for regexps that can match in multiple ways
            if (src.charAt(0) != "^") src = "^" + src;
            if (src.charAt(src.length - 1) != "$") src += "$";

            return new RegExp(src, (flag || "").replace("g", ""));
        };

        /**
         * Returns an object containing two properties: `tokens`, which contains all the tokens; and `state`, the current state.
         * @returns {Object}
         **/
        this.getLineTokens = function (line, startState) {
            if (startState && typeof startState != "string") {
                var stack = startState.slice(0);
                startState = stack[0];
                if (startState === "#tmp") {
                    stack.shift()
                    startState = stack.shift()
                }
            } else
                var stack = [];

            var currentState = startState || "start";
            var state = this.states[currentState];
            if (!state) {
                currentState = "start";
                state = this.states[currentState];
            }
            var mapping = this.matchMappings[currentState];
            var re = this.regExps[currentState];
            re.lastIndex = 0;

            var match, tokens = [];
            var lastIndex = 0;
            var matchAttempts = 0;

            var token = {type: null, value: ""};

            while (match = re.exec(line)) {
                var type = mapping.defaultToken;
                var rule = null;
                var value = match[0];
                var index = re.lastIndex;

                if (index - value.length > lastIndex) {
                    var skipped = line.substring(lastIndex, index - value.length);
                    if (token.type == type) {
                        token.value += skipped;
                    } else {
                        if (token.type)
                            tokens.push(token);
                        token = {type: type, value: skipped};
                    }
                }

                for (var i = 0; i < match.length - 2; i++) {
                    if (match[i + 1] === undefined)
                        continue;

                    rule = state[mapping[i]];

                    if (rule.onMatch)
                        type = rule.onMatch(value, currentState, stack);
                    else
                        type = rule.token;

                    if (rule.next) {
                        if (typeof rule.next == "string") {
                            currentState = rule.next;
                        } else {
                            currentState = rule.next(currentState, stack);
                        }

                        state = this.states[currentState];
                        if (!state) {
                            this.reportError("state doesn't exist", currentState);
                            currentState = "start";
                            state = this.states[currentState];
                        }
                        mapping = this.matchMappings[currentState];
                        lastIndex = index;
                        re = this.regExps[currentState];
                        re.lastIndex = index;
                    }
                    break;
                }

                if (value) {
                    if (typeof type === "string") {
                        if ((!rule || rule.merge !== false) && token.type === type) {
                            token.value += value;
                        } else {
                            if (token.type)
                                tokens.push(token);
                            token = {type: type, value: value};
                        }
                    } else if (type) {
                        if (token.type)
                            tokens.push(token);
                        token = {type: null, value: ""};
                        for (var i = 0; i < type.length; i++)
                            tokens.push(type[i]);
                    }
                }

                if (lastIndex == line.length)
                    break;

                lastIndex = index;

                if (matchAttempts++ > MAX_TOKEN_COUNT) {
                    if (matchAttempts > 2 * line.length) {
                        this.reportError("infinite loop with in ace tokenizer", {
                            startState: startState,
                            line: line
                        });
                    }
                    // chrome doens't show contents of text nodes with very long text
                    while (lastIndex < line.length) {
                        if (token.type)
                            tokens.push(token);
                        token = {
                            value: line.substring(lastIndex, lastIndex += 2000),
                            type: "overflow"
                        };
                    }
                    currentState = "start";
                    stack = [];
                    break;
                }
            }

            if (token.type)
                tokens.push(token);

            if (stack.length > 1) {
                if (stack[0] !== currentState)
                    stack.unshift("#tmp", currentState);
            }
            return {
                tokens: tokens,
                state: stack.length ? stack : currentState
            };
        };

        this.reportError = config.reportError;

    }).call(Tokenizer.prototype);

    exports.Tokenizer = Tokenizer;
});
