this.getLineTokens = function()

in lib/ace/tokenizer.js [228:362]
118 lines of code
35 McCabe index (conditional complexity)

    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, line);
                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;
                }
                if (rule.consumeLineEnd)
                    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 += 500),
                        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
        };
    };