function lex()

in Canvas/CanvasSimple/lib/winjs-4.0.1/js/base.js [8707:8816]
72 lines of code
17 McCabe index (conditional complexity)

                function lex(result, text, offset, limit) {
                    while (offset < limit) {
                        var startOffset = offset;
                        var code = text.charCodeAt(offset++);
                        var token;
                        switch (code) {
                            case isWhitespace(code) && code:
                            case isLineTerminator(code) && code:
                                offset = readWhitespace(text, offset, limit);
                                token = { type: tokenType.separator, length: offset - startOffset };
                                // don't include whitespace in the token stream.
                                continue;

                            case /*"*/34:
                            case /*'*/39:
                                token = readStringLiteralToken(text, offset - 1, limit);
                                break;

                            case /*(*/40:
                                token = tokens.leftParentheses;
                                break;

                            case /*)*/41:
                                token = tokens.rightParentheses;
                                break;

                            case /*+*/43:
                            case /*-*/45:
                                if (offset < limit) {
                                    var afterSign = text.charCodeAt(offset);
                                    if (afterSign === /*.*/46) {
                                        var signOffset = offset + 1;
                                        if (signOffset < limit && isDecimalDigit(text.charCodeAt(signOffset))) {
                                            token = readDecimalLiteralToken(text, startOffset, signOffset, limit);
                                            break;
                                        }
                                    } else if (isDecimalDigit(afterSign)) {
                                        token = readDecimalLiteralToken(text, startOffset, offset, limit);
                                        break;
                                    }
                                }
                                token = { type: tokenType.error, length: offset - startOffset, value: text.substring(startOffset, offset) };
                                break;

                            case /*,*/44:
                                token = tokens.comma;
                                break;

                            case /*.*/46:
                                token = tokens.dot;
                                if (offset < limit && isDecimalDigit(text.charCodeAt(offset))) {
                                    token = readDecimalLiteralToken(text, startOffset, offset, limit);
                                }
                                break;

                            case /*0*/48:
                                var ch2 = (offset < limit ? text.charCodeAt(offset) : 0);
                                if (ch2 === /*x*/120 || ch2 === /*X*/88) {
                                    var hexOffset = readHexIntegerLiteral(text, offset + 1, limit);
                                    token = {
                                        type: tokenType.numberLiteral,
                                        length: hexOffset - startOffset,
                                        value: +text.substr(startOffset, hexOffset - startOffset)
                                    };
                                } else {
                                    token = readDecimalLiteralToken(text, startOffset, offset, limit);
                                }
                                break;

                            case (code >= /*1*/49 && code <= /*9*/57) && code:
                                token = readDecimalLiteralToken(text, startOffset, offset, limit);
                                break;

                            case /*:*/58:
                                token = tokens.colon;
                                break;

                            case /*;*/59:
                                token = tokens.semicolon;
                                break;

                            case /*[*/91:
                                token = tokens.leftBracket;
                                break;

                            case /*]*/93:
                                token = tokens.rightBracket;
                                break;

                            case /*{*/123:
                                token = tokens.leftBrace;
                                break;

                            case /*}*/125:
                                token = tokens.rightBrace;
                                break;

                            default:
                                if (isIdentifierStartCharacter(code, text, offset, limit)) {
                                    token = readIdentifierToken(text, offset - 1, limit);
                                    break;
                                }
                                token = { type: tokenType.error, length: offset - startOffset, value: text.substring(startOffset, offset) };
                                break;
                        }

                        offset += (token.length - 1);
                        result.push(token);
                    }
                }