energylink/src/app/services/graphite/lexer.js

define([
  'lodash'
], function(_) {
  'use strict';

  // This is auto generated from the unicode tables.
  // The tables are at:
  // http://www.fileformat.info/info/unicode/category/Lu/list.htm
  // http://www.fileformat.info/info/unicode/category/Ll/list.htm
  // http://www.fileformat.info/info/unicode/category/Lt/list.htm
  // http://www.fileformat.info/info/unicode/category/Lm/list.htm
  // http://www.fileformat.info/info/unicode/category/Lo/list.htm
  // http://www.fileformat.info/info/unicode/category/Nl/list.htm

  var unicodeLetterTable = [
    170, 170, 181, 181, 186, 186, 192, 214,
    216, 246, 248, 705, 710, 721, 736, 740, 748, 748, 750, 750,
    880, 884, 886, 887, 890, 893, 902, 902, 904, 906, 908, 908,
    910, 929, 931, 1013, 1015, 1153, 1162, 1319, 1329, 1366,
    1369, 1369, 1377, 1415, 1488, 1514, 1520, 1522, 1568, 1610,
    1646, 1647, 1649, 1747, 1749, 1749, 1765, 1766, 1774, 1775,
    1786, 1788, 1791, 1791, 1808, 1808, 1810, 1839, 1869, 1957,
    1969, 1969, 1994, 2026, 2036, 2037, 2042, 2042, 2048, 2069,
    2074, 2074, 2084, 2084, 2088, 2088, 2112, 2136, 2308, 2361,
    2365, 2365, 2384, 2384, 2392, 2401, 2417, 2423, 2425, 2431,
    2437, 2444, 2447, 2448, 2451, 2472, 2474, 2480, 2482, 2482,
    2486, 2489, 2493, 2493, 2510, 2510, 2524, 2525, 2527, 2529,
    2544, 2545, 2565, 2570, 2575, 2576, 2579, 2600, 2602, 2608,
    2610, 2611, 2613, 2614, 2616, 2617, 2649, 2652, 2654, 2654,
    2674, 2676, 2693, 2701, 2703, 2705, 2707, 2728, 2730, 2736,
    2738, 2739, 2741, 2745, 2749, 2749, 2768, 2768, 2784, 2785,
    2821, 2828, 2831, 2832, 2835, 2856, 2858, 2864, 2866, 2867,
    2869, 2873, 2877, 2877, 2908, 2909, 2911, 2913, 2929, 2929,
    2947, 2947, 2949, 2954, 2958, 2960, 2962, 2965, 2969, 2970,
    2972, 2972, 2974, 2975, 2979, 2980, 2984, 2986, 2990, 3001,
    3024, 3024, 3077, 3084, 3086, 3088, 3090, 3112, 3114, 3123,
    3125, 3129, 3133, 3133, 3160, 3161, 3168, 3169, 3205, 3212,
    3214, 3216, 3218, 3240, 3242, 3251, 3253, 3257, 3261, 3261,
    3294, 3294, 3296, 3297, 3313, 3314, 3333, 3340, 3342, 3344,
    3346, 3386, 3389, 3389, 3406, 3406, 3424, 3425, 3450, 3455,
    3461, 3478, 3482, 3505, 3507, 3515, 3517, 3517, 3520, 3526,
    3585, 3632, 3634, 3635, 3648, 3654, 3713, 3714, 3716, 3716,
    3719, 3720, 3722, 3722, 3725, 3725, 3732, 3735, 3737, 3743,
    3745, 3747, 3749, 3749, 3751, 3751, 3754, 3755, 3757, 3760,
    3762, 3763, 3773, 3773, 3776, 3780, 3782, 3782, 3804, 3805,
    3840, 3840, 3904, 3911, 3913, 3948, 3976, 3980, 4096, 4138,
    4159, 4159, 4176, 4181, 4186, 4189, 4193, 4193, 4197, 4198,
    4206, 4208, 4213, 4225, 4238, 4238, 4256, 4293, 4304, 4346,
    4348, 4348, 4352, 4680, 4682, 4685, 4688, 4694, 4696, 4696,
    4698, 4701, 4704, 4744, 4746, 4749, 4752, 4784, 4786, 4789,
    4792, 4798, 4800, 4800, 4802, 4805, 4808, 4822, 4824, 4880,
    4882, 4885, 4888, 4954, 4992, 5007, 5024, 5108, 5121, 5740,
    5743, 5759, 5761, 5786, 5792, 5866, 5870, 5872, 5888, 5900,
    5902, 5905, 5920, 5937, 5952, 5969, 5984, 5996, 5998, 6000,
    6016, 6067, 6103, 6103, 6108, 6108, 6176, 6263, 6272, 6312,
    6314, 6314, 6320, 6389, 6400, 6428, 6480, 6509, 6512, 6516,
    6528, 6571, 6593, 6599, 6656, 6678, 6688, 6740, 6823, 6823,
    6917, 6963, 6981, 6987, 7043, 7072, 7086, 7087, 7104, 7141,
    7168, 7203, 7245, 7247, 7258, 7293, 7401, 7404, 7406, 7409,
    7424, 7615, 7680, 7957, 7960, 7965, 7968, 8005, 8008, 8013,
    8016, 8023, 8025, 8025, 8027, 8027, 8029, 8029, 8031, 8061,
    8064, 8116, 8118, 8124, 8126, 8126, 8130, 8132, 8134, 8140,
    8144, 8147, 8150, 8155, 8160, 8172, 8178, 8180, 8182, 8188,
    8305, 8305, 8319, 8319, 8336, 8348, 8450, 8450, 8455, 8455,
    8458, 8467, 8469, 8469, 8473, 8477, 8484, 8484, 8486, 8486,
    8488, 8488, 8490, 8493, 8495, 8505, 8508, 8511, 8517, 8521,
    8526, 8526, 8544, 8584, 11264, 11310, 11312, 11358,
    11360, 11492, 11499, 11502, 11520, 11557, 11568, 11621,
    11631, 11631, 11648, 11670, 11680, 11686, 11688, 11694,
    11696, 11702, 11704, 11710, 11712, 11718, 11720, 11726,
    11728, 11734, 11736, 11742, 11823, 11823, 12293, 12295,
    12321, 12329, 12337, 12341, 12344, 12348, 12353, 12438,
    12445, 12447, 12449, 12538, 12540, 12543, 12549, 12589,
    12593, 12686, 12704, 12730, 12784, 12799, 13312, 13312,
    19893, 19893, 19968, 19968, 40907, 40907, 40960, 42124,
    42192, 42237, 42240, 42508, 42512, 42527, 42538, 42539,
    42560, 42606, 42623, 42647, 42656, 42735, 42775, 42783,
    42786, 42888, 42891, 42894, 42896, 42897, 42912, 42921,
    43002, 43009, 43011, 43013, 43015, 43018, 43020, 43042,
    43072, 43123, 43138, 43187, 43250, 43255, 43259, 43259,
    43274, 43301, 43312, 43334, 43360, 43388, 43396, 43442,
    43471, 43471, 43520, 43560, 43584, 43586, 43588, 43595,
    43616, 43638, 43642, 43642, 43648, 43695, 43697, 43697,
    43701, 43702, 43705, 43709, 43712, 43712, 43714, 43714,
    43739, 43741, 43777, 43782, 43785, 43790, 43793, 43798,
    43808, 43814, 43816, 43822, 43968, 44002, 44032, 44032,
    55203, 55203, 55216, 55238, 55243, 55291, 63744, 64045,
    64048, 64109, 64112, 64217, 64256, 64262, 64275, 64279,
    64285, 64285, 64287, 64296, 64298, 64310, 64312, 64316,
    64318, 64318, 64320, 64321, 64323, 64324, 64326, 64433,
    64467, 64829, 64848, 64911, 64914, 64967, 65008, 65019,
    65136, 65140, 65142, 65276, 65313, 65338, 65345, 65370,
    65382, 65470, 65474, 65479, 65482, 65487, 65490, 65495,
    65498, 65500, 65536, 65547, 65549, 65574, 65576, 65594,
    65596, 65597, 65599, 65613, 65616, 65629, 65664, 65786,
    65856, 65908, 66176, 66204, 66208, 66256, 66304, 66334,
    66352, 66378, 66432, 66461, 66464, 66499, 66504, 66511,
    66513, 66517, 66560, 66717, 67584, 67589, 67592, 67592,
    67594, 67637, 67639, 67640, 67644, 67644, 67647, 67669,
    67840, 67861, 67872, 67897, 68096, 68096, 68112, 68115,
    68117, 68119, 68121, 68147, 68192, 68220, 68352, 68405,
    68416, 68437, 68448, 68466, 68608, 68680, 69635, 69687,
    69763, 69807, 73728, 74606, 74752, 74850, 77824, 78894,
    92160, 92728, 110592, 110593, 119808, 119892, 119894, 119964,
    119966, 119967, 119970, 119970, 119973, 119974, 119977, 119980,
    119982, 119993, 119995, 119995, 119997, 120003, 120005, 120069,
    120071, 120074, 120077, 120084, 120086, 120092, 120094, 120121,
    120123, 120126, 120128, 120132, 120134, 120134, 120138, 120144,
    120146, 120485, 120488, 120512, 120514, 120538, 120540, 120570,
    120572, 120596, 120598, 120628, 120630, 120654, 120656, 120686,
    120688, 120712, 120714, 120744, 120746, 120770, 120772, 120779,
    131072, 131072, 173782, 173782, 173824, 173824, 177972, 177972,
    177984, 177984, 178205, 178205, 194560, 195101
  ];

  var identifierStartTable = [];

  for (var i = 0; i < 128; i++) {
    identifierStartTable[i] =
      i >= 48 && i <= 57 || // 0-9
      i === 36 ||           // $
      i >= 65 && i <= 90 || // A-Z
      i === 95 ||           // _
      i === 45 ||           // -
      i === 42 ||           // *
      i === 58 ||           // :
      i === 91 ||           // templateStart [
      i === 93 ||           // templateEnd ]
      i === 63 ||           // ?
      i === 37 ||           // %
      i >= 97 && i <= 122;  // a-z
  }

  var identifierPartTable = [];

  for (var i2 = 0; i2 < 128; i2++) {
    identifierPartTable[i2] =
      identifierStartTable[i2] || // $, _, A-Z, a-z
      i2 >= 48 && i2 <= 57;        // 0-9
  }

  function Lexer(expression) {
    this.input = expression;
    this.char = 1;
    this.from = 1;
  }

  Lexer.prototype = {

    peek: function (i) {
      return this.input.charAt(i || 0);
    },

    skip: function (i) {
      i = i || 1;
      this.char += i;
      this.input = this.input.slice(i);
    },

    tokenize: function() {
      var list = [];
      var token;
      while (token = this.next()) {
        list.push(token);
      }
      return list;
    },

    next: function() {
      this.from = this.char;

      // Move to the next non-space character.
      var start;
      if (/\s/.test(this.peek())) {
        start = this.char;

        while (/\s/.test(this.peek())) {
          this.from += 1;
          this.skip();
        }

        if (this.peek() === "") { // EOL
          return null;
        }
      }

      var match = this.scanStringLiteral();
      if (match) {
        return match;
      }

      match =
        this.scanPunctuator() ||
        this.scanNumericLiteral() ||
        this.scanIdentifier() ||
        this.scanTemplateSequence();

      if (match) {
        this.skip(match.value.length);
        return match;
      }

      // No token could be matched, give up.
      return null;
    },

    scanTemplateSequence: function() {
      if (this.peek() === '[' && this.peek(1) === '[') {
        return {
          type: 'templateStart',
          value: '[[',
          pos: this.char
        };
      }

      if (this.peek() === ']' && this.peek(1) === ']') {
        return {
          type: 'templateEnd',
          value: '[[',
          pos: this.char
        };
      }

      return null;
    },

      /*
     * Extract a JavaScript identifier out of the next sequence of
     * characters or return 'null' if its not possible. In addition,
     * to Identifier this method can also produce BooleanLiteral
     * (true/false) and NullLiteral (null).
     */
    scanIdentifier: function() {
      var id = "";
      var index = 0;
      var type, char;

      // Detects any character in the Unicode categories "Uppercase
      // letter (Lu)", "Lowercase letter (Ll)", "Titlecase letter
      // (Lt)", "Modifier letter (Lm)", "Other letter (Lo)", or
      // "Letter number (Nl)".
      //
      // Both approach and unicodeLetterTable were borrowed from
      // Google's Traceur.

      function isUnicodeLetter(code) {
        for (var i = 0; i < unicodeLetterTable.length;) {
          if (code < unicodeLetterTable[i++]) {
            return false;
          }

          if (code <= unicodeLetterTable[i++]) {
            return true;
          }
        }

        return false;
      }

      function isHexDigit(str) {
        return (/^[0-9a-fA-F]$/).test(str);
      }

      var readUnicodeEscapeSequence = _.bind(function () {
        /*jshint validthis:true */
        index += 1;

        if (this.peek(index) !== "u") {
          return null;
        }

        var ch1 = this.peek(index + 1);
        var ch2 = this.peek(index + 2);
        var ch3 = this.peek(index + 3);
        var ch4 = this.peek(index + 4);
        var code;

        if (isHexDigit(ch1) && isHexDigit(ch2) && isHexDigit(ch3) && isHexDigit(ch4)) {
          code = parseInt(ch1 + ch2 + ch3 + ch4, 16);

          if (isUnicodeLetter(code)) {
            index += 5;
            return "\\u" + ch1 + ch2 + ch3 + ch4;
          }

          return null;
        }

        return null;
      }, this);

      var getIdentifierStart = _.bind(function () {
        /*jshint validthis:true */
        var chr = this.peek(index);
        var code = chr.charCodeAt(0);

        if (chr === '*') {
          index += 1;
          return chr;
        }

        if (code === 92) {
          return readUnicodeEscapeSequence();
        }

        if (code < 128) {
          if (identifierStartTable[code]) {
            index += 1;
            return chr;
          }

          return null;
        }

        if (isUnicodeLetter(code)) {
          index += 1;
          return chr;
        }

        return null;
      }, this);

      var getIdentifierPart = _.bind(function () {
        /*jshint validthis:true */
        var chr = this.peek(index);
        var code = chr.charCodeAt(0);

        if (code === 92) {
          return readUnicodeEscapeSequence();
        }

        if (code < 128) {
          if (identifierPartTable[code]) {
            index += 1;
            return chr;
          }

          return null;
        }

        if (isUnicodeLetter(code)) {
          index += 1;
          return chr;
        }

        return null;
      }, this);

      char = getIdentifierStart();
      if (char === null) {
        return null;
      }

      id = char;
      for (;;) {
        char = getIdentifierPart();

        if (char === null) {
          break;
        }

        id += char;
      }

      switch (id) {
      default:
        type = "identifier";
      }

      return {
        type: type,
        value: id,
        pos: this.char
      };

    },

      /*
     * Extract a numeric literal out of the next sequence of
     * characters or return 'null' if its not possible. This method
     * supports all numeric literals described in section 7.8.3
     * of the EcmaScript 5 specification.
     *
     * This method's implementation was heavily influenced by the
     * scanNumericLiteral function in the Esprima parser's source code.
     */
    scanNumericLiteral: function () {
      var index = 0;
      var value = "";
      var length = this.input.length;
      var char = this.peek(index);
      var bad;

      function isDecimalDigit(str) {
        return (/^[0-9]$/).test(str);
      }

      function isOctalDigit(str) {
        return (/^[0-7]$/).test(str);
      }

      function isHexDigit(str) {
        return (/^[0-9a-fA-F]$/).test(str);
      }

      function isIdentifierStart(ch) {
        return (ch === "$") || (ch === "_") || (ch === "\\") ||
          (ch >= "a" && ch <= "z") || (ch >= "A" && ch <= "Z");
      }

      // handle negative num literals
      if (char === '-') {
        value += char;
        index += 1;
        char = this.peek(index);
      }

      // Numbers must start either with a decimal digit or a point.
      if (char !== "." && !isDecimalDigit(char)) {
        return null;
      }

      if (char !== ".") {
        value += this.peek(index);
        index += 1;
        char = this.peek(index);

        if (value === "0") {
          // Base-16 numbers.
          if (char === "x" || char === "X") {
            index += 1;
            value += char;

            while (index < length) {
              char = this.peek(index);
              if (!isHexDigit(char)) {
                break;
              }
              value += char;
              index += 1;
            }

            if (value.length <= 2) { // 0x
              return {
                type: 'number',
                value: value,
                isMalformed: true,
                pos: this.char
              };
            }

            if (index < length) {
              char = this.peek(index);
              if (isIdentifierStart(char)) {
                return null;
              }
            }

            return {
              type: 'number',
              value: value,
              base: 16,
              isMalformed: false,
              pos: this.char
            };
          }

          // Base-8 numbers.
          if (isOctalDigit(char)) {
            index += 1;
            value += char;
            bad = false;

            while (index < length) {
              char = this.peek(index);

              // Numbers like '019' (note the 9) are not valid octals
              // but we still parse them and mark as malformed.

              if (isDecimalDigit(char)) {
                bad = true;
              } else if (!isOctalDigit(char)) {
                break;
              }
              value += char;
              index += 1;
            }

            if (index < length) {
              char = this.peek(index);
              if (isIdentifierStart(char)) {
                return null;
              }
            }

            return {
              type: 'number',
              value: value,
              base: 8,
              isMalformed: false
            };
          }

          // Decimal numbers that start with '0' such as '09' are illegal
          // but we still parse them and return as malformed.

          if (isDecimalDigit(char)) {
            index += 1;
            value += char;
          }
        }

        while (index < length) {
          char = this.peek(index);
          if (!isDecimalDigit(char)) {
            break;
          }
          value += char;
          index += 1;
        }
      }

      // Decimal digits.

      if (char === ".") {
        value += char;
        index += 1;

        while (index < length) {
          char = this.peek(index);
          if (!isDecimalDigit(char)) {
            break;
          }
          value += char;
          index += 1;
        }
      }

      // Exponent part.

      if (char === "e" || char === "E") {
        value += char;
        index += 1;
        char = this.peek(index);

        if (char === "+" || char === "-") {
          value += this.peek(index);
          index += 1;
        }

        char = this.peek(index);
        if (isDecimalDigit(char)) {
          value += char;
          index += 1;

          while (index < length) {
            char = this.peek(index);
            if (!isDecimalDigit(char)) {
              break;
            }
            value += char;
            index += 1;
          }
        } else {
          return null;
        }
      }

      if (index < length) {
        char = this.peek(index);
        if (!this.isPunctuator(char)) {
          return null;
        }
      }

      return {
        type: 'number',
        value: value,
        base: 10,
        pos: this.char,
        isMalformed: !isFinite(value)
      };
    },

    isPunctuator: function (ch1) {
      switch (ch1) {
      case ".":
      case "(":
      case ")":
      case ",":
      case "{":
      case "}":
        return true;
      }

      return false;
    },

    scanPunctuator: function () {
      var ch1 = this.peek();

      if (this.isPunctuator(ch1)) {
        return {
          type: ch1,
          value: ch1,
          pos: this.char
        };
      }

      return null;
    },

      /*
     * Extract a string out of the next sequence of characters and/or
     * lines or return 'null' if its not possible. Since strings can
     * span across multiple lines this method has to move the char
     * pointer.
     *
     * This method recognizes pseudo-multiline JavaScript strings:
     *
     *   var str = "hello\
     *   world";
     */
    scanStringLiteral: function () {
      /*jshint loopfunc:true */
      var quote = this.peek();

      // String must start with a quote.
      if (quote !== "\"" && quote !== "'") {
        return null;
      }

      var value = "";

      this.skip();

      while (this.peek() !== quote) {
        if (this.peek() === "") { // End Of Line
          return {
            type: 'string',
            value: value,
            isUnclosed: true,
            quote: quote,
            pos: this.char
          };
        }

        var char = this.peek();
        var jump = 1; // A length of a jump, after we're done
                      // parsing this character.

        value += char;
        this.skip(jump);
      }

      this.skip();
      return {
        type: 'string',
        value: value,
        isUnclosed: false,
        quote: quote,
        pos: this.char
      };
    },

  };

  return Lexer;

});