// regjsparser
//
// ==================================================================
//
// See ECMA-262 Standard: 15.10.1
//
// NOTE: The ECMA-262 standard uses the term "Assertion" for /^/. Here the
//   term "Anchor" is used.
//
// Pattern ::
//      Disjunction
//
// Disjunction ::
//      Alternative
//      Alternative | Disjunction
//
// Alternative ::
//      [empty]
//      Alternative Term
//
// Term ::
//      Anchor
//      Atom
//      Atom Quantifier
//
// Anchor ::
//      ^
//      $
//      \ b
//      \ B
//      ( ? = Disjunction )
//      ( ? ! Disjunction )
//
// Quantifier ::
//      QuantifierPrefix
//      QuantifierPrefix ?
//
// QuantifierPrefix ::
//      *
//      +
//      ?
//      { DecimalDigits }
//      { DecimalDigits , }
//      { DecimalDigits , DecimalDigits }
//
// Atom ::
//      PatternCharacter
//      .
//      \ AtomEscape
//      CharacterClass
//      ( Disjunction )
//      ( ? : Disjunction )
//
// PatternCharacter ::
//      SourceCharacter but not any of: ^ $ \ . * + ? ( ) [ ] { } |
//
// AtomEscape ::
//      DecimalEscape
//      CharacterEscape
//      CharacterClassEscape
//
// CharacterEscape[U] ::
//      ControlEscape
//      c ControlLetter
//      HexEscapeSequence
//      RegExpUnicodeEscapeSequence[?U] (ES6)
//      IdentityEscape[?U]
//
// ControlEscape ::
//      one of f n r t v
// ControlLetter ::
//      one of
//          a b c d e f g h i j k l m n o p q r s t u v w x y z
//          A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
//
// IdentityEscape ::
//      SourceCharacter but not IdentifierPart
//      <ZWJ>
//      <ZWNJ>
//
// DecimalEscape ::
//      DecimalIntegerLiteral [lookahead ∉ DecimalDigit]
//
// CharacterClassEscape ::
//      one of d D s S w W
//
// CharacterClass ::
//      [ [lookahead ∉ {^}] ClassRanges ]
//      [ ^ ClassRanges ]
//
// ClassRanges ::
//      [empty]
//      NonemptyClassRanges
//
// NonemptyClassRanges ::
//      ClassAtom
//      ClassAtom NonemptyClassRangesNoDash
//      ClassAtom - ClassAtom ClassRanges
//
// NonemptyClassRangesNoDash ::
//      ClassAtom
//      ClassAtomNoDash NonemptyClassRangesNoDash
//      ClassAtomNoDash - ClassAtom ClassRanges
//
// ClassAtom ::
//      -
//      ClassAtomNoDash
//
// ClassAtomNoDash ::
//      SourceCharacter but not one of \ or ] or -
//      \ ClassEscape
//
// ClassEscape ::
//      DecimalEscape
//      b
//      CharacterEscape
//      CharacterClassEscape

(function() {

  function parse(str, flags) {
    function addRaw(node) {
      node.raw = str.substring(node.range[0], node.range[1]);
      return node;
    }

    function updateRawStart(node, start) {
      node.range[0] = start;
      return addRaw(node);
    }

    function createAnchor(kind, rawLength) {
      return addRaw({
        type: 'anchor',
        kind: kind,
        range: [
          pos - rawLength,
          pos
        ]
      });
    }

    function createValue(kind, codePoint, from, to) {
      return addRaw({
        type: 'value',
        kind: kind,
        codePoint: codePoint,
        range: [from, to]
      });
    }

    function createEscaped(kind, codePoint, value, fromOffset) {
      fromOffset = fromOffset || 0;
      return createValue(kind, codePoint, pos - (value.length + fromOffset), pos);
    }

    function createCharacter(matches) {
      var _char = matches[0];
      var first = _char.charCodeAt(0);
      if (hasUnicodeFlag) {
        var second;
        if (_char.length === 1 && first >= 0xD800 && first <= 0xDBFF) {
          second = lookahead().charCodeAt(0);
          if (second >= 0xDC00 && second <= 0xDFFF) {
            // Unicode surrogate pair
            pos++;
            return createValue(
                'symbol',
                (first - 0xD800) * 0x400 + second - 0xDC00 + 0x10000,
                pos - 2, pos);
          }
        }
      }
      return createValue('symbol', first, pos - 1, pos);
    }

    function createDisjunction(alternatives, from, to) {
      return addRaw({
        type: 'disjunction',
        body: alternatives,
        range: [
          from,
          to
        ]
      });
    }

    function createDot() {
      return addRaw({
        type: 'dot',
        range: [
          pos - 1,
          pos
        ]
      });
    }

    function createCharacterClassEscape(value) {
      return addRaw({
        type: 'characterClassEscape',
        value: value,
        range: [
          pos - 2,
          pos
        ]
      });
    }

    function createReference(matchIndex) {
      return addRaw({
        type: 'reference',
        matchIndex: parseInt(matchIndex, 10),
        range: [
          pos - 1 - matchIndex.length,
          pos
        ]
      });
    }

    function createGroup(behavior, disjunction, from, to) {
      return addRaw({
        type: 'group',
        behavior: behavior,
        body: disjunction,
        range: [
          from,
          to
        ]
      });
    }

    function createQuantifier(min, max, from, to) {
      if (to == null) {
        from = pos - 1;
        to = pos;
      }

      return addRaw({
        type: 'quantifier',
        min: min,
        max: max,
        greedy: true,
        body: null, // set later on,
        range: [
          from,
          to
        ]
      });
    }

    function createAlternative(terms, from, to) {
      return addRaw({
        type: 'alternative',
        body: terms,
        range: [
          from,
          to
        ]
      });
    }

    function createCharacterClass(classRanges, negative, from, to) {
      return addRaw({
        type: 'characterClass',
        body: classRanges,
        negative: negative,
        range: [
          from,
          to
        ]
      });
    }

    function createClassRange(min, max, from, to) {
      // See 15.10.2.15:
      if (min.codePoint > max.codePoint) {
        throw SyntaxError('invalid range in character class');
      }

      return addRaw({
        type: 'characterClassRange',
        min: min,
        max: max,
        range: [
          from,
          to
        ]
      });
    }

    function flattenBody(body) {
      if (body.type === 'alternative') {
        return body.body;
      } else {
        return [body];
      }
    }

    function isEmpty(obj) {
      return obj.type === 'empty';
    }

    function incr(amount) {
      amount = (amount || 1);
      var res = str.substring(pos, pos + amount);
      pos += (amount || 1);
      return res;
    }

    function skip(value) {
      if (!match(value)) {
        throw SyntaxError('character: ' + value);
      }
    }

    function match(value) {
      if (str.indexOf(value, pos) === pos) {
        return incr(value.length);
      }
    }

    function lookahead() {
      return str[pos];
    }

    function current(value) {
      return str.indexOf(value, pos) === pos;
    }

    function next(value) {
      return str[pos + 1] === value;
    }

    function matchReg(regExp) {
      var subStr = str.substring(pos);
      var res = subStr.match(regExp);
      if (res) {
        res.range = [];
        res.range[0] = pos;
        incr(res[0].length);
        res.range[1] = pos;
      }
      return res;
    }

    function parseDisjunction() {
      // Disjunction ::
      //      Alternative
      //      Alternative | Disjunction
      var res = [], from = pos;
      res.push(parseAlternative());

      while (match('|')) {
        res.push(parseAlternative());
      }

      if (res.length === 1) {
        return res[0];
      }

      return createDisjunction(res, from, pos);
    }

    function parseAlternative() {
      var res = [], from = pos;
      var term;

      // Alternative ::
      //      [empty]
      //      Alternative Term
      while (term = parseTerm()) {
        res.push(term);
      }

      if (res.length === 1) {
        return res[0];
      }

      return createAlternative(res, from, pos);
    }

    function parseTerm() {
      // Term ::
      //      Anchor
      //      Atom
      //      Atom Quantifier

      if (pos >= str.length || current('|') || current(')')) {
        return null; /* Means: The term is empty */
      }

      var anchor = parseAnchor();

      if (anchor) {
        return anchor;
      }

      var atom = parseAtom();
      if (!atom) {
        throw SyntaxError('Expected atom')
      }
      var quantifier = parseQuantifier() || false;
      if (quantifier) {
        quantifier.body = flattenBody(atom);
        // The quantifier contains the atom. Therefore, the beginning of the
        // quantifier range is given by the beginning of the atom.
        updateRawStart(quantifier, atom.range[0]);
        return quantifier;
      }
      return atom;
    }

    function parseGroup(matchA, typeA, matchB, typeB) {
      var type = null, from = pos;

      if (match(matchA)) {
        type = typeA;
      } else if (match(matchB)) {
        type = typeB;
      } else {
        return false;
      }

      var body = parseDisjunction();
      if (!body) {
        throw SyntaxError('Expected disjunction');
      }
      skip(')');
      var group = createGroup(type, flattenBody(body), from, pos);

      if (type == 'normal') {
        // Keep track of the number of closed groups. This is required for
        // parseDecimalEscape(). In case the string is parsed a second time the
        // value already holds the total count and no incrementation is required.
        if (firstIteration) {
          closedCaptureCounter++;
        }
      }
      return group;
    }

    function parseAnchor() {
      // Anchor ::
      //      ^
      //      $
      //      \ b
      //      \ B
      //      ( ? = Disjunction )
      //      ( ? ! Disjunction )
      var res, from = pos;

      if (match('^')) {
        return createAnchor('start', 1 /* rawLength */);
      } else if (match('$')) {
        return createAnchor('end', 1 /* rawLength */);
      } else if (match('\\b')) {
        return createAnchor('boundary', 2 /* rawLength */);
      } else if (match('\\B')) {
        return createAnchor('not-boundary', 2 /* rawLength */);
      } else {
        return parseGroup('(?=', 'lookahead', '(?!', 'negativeLookahead');
      }
    }

    function parseQuantifier() {
      // Quantifier ::
      //      QuantifierPrefix
      //      QuantifierPrefix ?
      //
      // QuantifierPrefix ::
      //      *
      //      +
      //      ?
      //      { DecimalDigits }
      //      { DecimalDigits , }
      //      { DecimalDigits , DecimalDigits }

      var res;
      var quantifier;
      var min, max;

      if (match('*')) {
        quantifier = createQuantifier(0);
      }
      else if (match('+')) {
        quantifier = createQuantifier(1);
      }
      else if (match('?')) {
        quantifier = createQuantifier(0, 1);
      }
      else if (res = matchReg(/^\{([0-9]+)\}/)) {
        min = parseInt(res[1], 10);
        quantifier = createQuantifier(min, min, res.range[0], res.range[1]);
      }
      else if (res = matchReg(/^\{([0-9]+),\}/)) {
        min = parseInt(res[1], 10);
        quantifier = createQuantifier(min, undefined, res.range[0], res.range[1]);
      }
      else if (res = matchReg(/^\{([0-9]+),([0-9]+)\}/)) {
        min = parseInt(res[1], 10);
        max = parseInt(res[2], 10);
        if (min > max) {
          throw SyntaxError('numbers out of order in {} quantifier');
        }
        quantifier = createQuantifier(min, max, res.range[0], res.range[1]);
      }

      if (quantifier) {
        if (match('?')) {
          quantifier.greedy = false;
          quantifier.range[1] += 1;
        }
      }

      return quantifier;
    }

    function parseAtom() {
      // Atom ::
      //      PatternCharacter
      //      .
      //      \ AtomEscape
      //      CharacterClass
      //      ( Disjunction )
      //      ( ? : Disjunction )

      var res;

      // jviereck: allow ']', '}' here as well to be compatible with browser's
      //   implementations: ']'.match(/]/);
      // if (res = matchReg(/^[^^$\\.*+?()[\]{}|]/)) {
      if (res = matchReg(/^[^^$\\.*+?(){[|]/)) {
        //      PatternCharacter
        return createCharacter(res);
      }
      else if (match('.')) {
        //      .
        return createDot();
      }
      else if (match('\\')) {
        //      \ AtomEscape
        res = parseAtomEscape();
        if (!res) {
          throw SyntaxError('atomEscape');
        }
        return res;
      }
      else if (res = parseCharacterClass()) {
        return res;
      }
      else {
        //      ( Disjunction )
        //      ( ? : Disjunction )
        return parseGroup('(?:', 'ignore', '(', 'normal');
      }
    }

    function parseUnicodeSurrogatePairEscape(firstEscape) {
      if (hasUnicodeFlag) {
        var first, second;
        if (firstEscape.kind == 'unicodeEscape' &&
          (first = firstEscape.codePoint) >= 0xD800 && first <= 0xDBFF &&
          current('\\') && next('u') ) {
          var prevPos = pos;
          pos++;
          var secondEscape = parseClassEscape();
          if (secondEscape.kind == 'unicodeEscape' &&
            (second = secondEscape.codePoint) >= 0xDC00 && second <= 0xDFFF) {
            // Unicode surrogate pair
            firstEscape.range[1] = secondEscape.range[1];
            firstEscape.codePoint = (first - 0xD800) * 0x400 + second - 0xDC00 + 0x10000;
            firstEscape.type = 'value';
            firstEscape.kind = 'unicodeCodePointEscape';
            addRaw(firstEscape);
          }
          else {
            pos = prevPos;
          }
        }
      }
      return firstEscape;
    }

    function parseClassEscape() {
      return parseAtomEscape(true);
    }

    function parseAtomEscape(insideCharacterClass) {
      // AtomEscape ::
      //      DecimalEscape
      //      CharacterEscape
      //      CharacterClassEscape

      var res;

      res = parseDecimalEscape();
      if (res) {
        return res;
      }

      // For ClassEscape
      if (insideCharacterClass) {
        if (match('b')) {
          // 15.10.2.19
          // The production ClassEscape :: b evaluates by returning the
          // CharSet containing the one character <BS> (Unicode value 0008).
          return createEscaped('singleEscape', 0x0008, '\\b');
        } else if (match('B')) {
          throw SyntaxError('\\B not possible inside of CharacterClass');
        }
      }

      res = parseCharacterEscape();

      return res;
    }


    function parseDecimalEscape() {
      // DecimalEscape ::
      //      DecimalIntegerLiteral [lookahead ∉ DecimalDigit]
      //      CharacterClassEscape :: one of d D s S w W

      var res, match;

      if (res = matchReg(/^(?!0)\d+/)) {
        match = res[0];
        var refIdx = parseInt(res[0], 10);
        if (refIdx <= closedCaptureCounter) {
          // If the number is smaller than the normal-groups found so
          // far, then it is a reference...
          return createReference(res[0]);
        } else {
          // ... otherwise it needs to be interpreted as a octal (if the
          // number is in an octal format). If it is NOT octal format,
          // then the slash is ignored and the number is matched later
          // as normal characters.

          // Recall the negative decision to decide if the input must be parsed
          // a second time with the total normal-groups.
          backrefDenied.push(refIdx);

          // Reset the position again, as maybe only parts of the previous
          // matched numbers are actual octal numbers. E.g. in '019' only
          // the '01' should be matched.
          incr(-res[0].length);
          if (res = matchReg(/^[0-7]{1,3}/)) {
            return createEscaped('octal', parseInt(res[0], 8), res[0], 1);
          } else {
            // If we end up here, we have a case like /\91/. Then the
            // first slash is to be ignored and the 9 & 1 to be treated
            // like ordinary characters. Create a character for the
            // first number only here - other number-characters
            // (if available) will be matched later.
            res = createCharacter(matchReg(/^[89]/));
            return updateRawStart(res, res.range[0] - 1);
          }
        }
      }
      // Only allow octal numbers in the following. All matched numbers start
      // with a zero (if the do not, the previous if-branch is executed).
      // If the number is not octal format and starts with zero (e.g. `091`)
      // then only the zeros `0` is treated here and the `91` are ordinary
      // characters.
      // Example:
      //   /\091/.exec('\091')[0].length === 3
      else if (res = matchReg(/^[0-7]{1,3}/)) {
        match = res[0];
        if (/^0{1,3}$/.test(match)) {
          // If they are all zeros, then only take the first one.
          return createEscaped('null', 0x0000, '0', match.length + 1);
        } else {
          return createEscaped('octal', parseInt(match, 8), match, 1);
        }
      } else if (res = matchReg(/^[dDsSwW]/)) {
        return createCharacterClassEscape(res[0]);
      }
      return false;
    }

    function parseCharacterEscape() {
      // CharacterEscape ::
      //      ControlEscape
      //      c ControlLetter
      //      HexEscapeSequence
      //      UnicodeEscapeSequence
      //      IdentityEscape

      var res;
      if (res = matchReg(/^[fnrtv]/)) {
        // ControlEscape
        var codePoint = 0;
        switch (res[0]) {
          case 't': codePoint = 0x009; break;
          case 'n': codePoint = 0x00A; break;
          case 'v': codePoint = 0x00B; break;
          case 'f': codePoint = 0x00C; break;
          case 'r': codePoint = 0x00D; break;
        }
        return createEscaped('singleEscape', codePoint, '\\' + res[0]);
      } else if (res = matchReg(/^c([a-zA-Z])/)) {
        // c ControlLetter
        return createEscaped('controlLetter', res[1].charCodeAt(0) % 32, res[1], 2);
      } else if (res = matchReg(/^x([0-9a-fA-F]{2})/)) {
        // HexEscapeSequence
        return createEscaped('hexadecimalEscape', parseInt(res[1], 16), res[1], 2);
      } else if (res = matchReg(/^u([0-9a-fA-F]{4})/)) {
        // UnicodeEscapeSequence
        return parseUnicodeSurrogatePairEscape(
          createEscaped('unicodeEscape', parseInt(res[1], 16), res[1], 2)
        );
      } else if (hasUnicodeFlag && (res = matchReg(/^u\{([0-9a-fA-F]+)\}/))) {
        // RegExpUnicodeEscapeSequence (ES6 Unicode code point escape)
        return createEscaped('unicodeCodePointEscape', parseInt(res[1], 16), res[1], 4);
      } else {
        // IdentityEscape
        return parseIdentityEscape();
      }
    }

    // Taken from the Esprima parser.
    function isIdentifierPart(ch) {
      // Generated by `tools/generate-identifier-regex.js`.
      var NonAsciiIdentifierPart = new RegExp('[\xAA\xB5\xBA\xC0-\xD6\xD8-\xF6\xF8-\u02C1\u02C6-\u02D1\u02E0-\u02E4\u02EC\u02EE\u0300-\u0374\u0376\u0377\u037A-\u037D\u037F\u0386\u0388-\u038A\u038C\u038E-\u03A1\u03A3-\u03F5\u03F7-\u0481\u0483-\u0487\u048A-\u052F\u0531-\u0556\u0559\u0561-\u0587\u0591-\u05BD\u05BF\u05C1\u05C2\u05C4\u05C5\u05C7\u05D0-\u05EA\u05F0-\u05F2\u0610-\u061A\u0620-\u0669\u066E-\u06D3\u06D5-\u06DC\u06DF-\u06E8\u06EA-\u06FC\u06FF\u0710-\u074A\u074D-\u07B1\u07C0-\u07F5\u07FA\u0800-\u082D\u0840-\u085B\u08A0-\u08B2\u08E4-\u0963\u0966-\u096F\u0971-\u0983\u0985-\u098C\u098F\u0990\u0993-\u09A8\u09AA-\u09B0\u09B2\u09B6-\u09B9\u09BC-\u09C4\u09C7\u09C8\u09CB-\u09CE\u09D7\u09DC\u09DD\u09DF-\u09E3\u09E6-\u09F1\u0A01-\u0A03\u0A05-\u0A0A\u0A0F\u0A10\u0A13-\u0A28\u0A2A-\u0A30\u0A32\u0A33\u0A35\u0A36\u0A38\u0A39\u0A3C\u0A3E-\u0A42\u0A47\u0A48\u0A4B-\u0A4D\u0A51\u0A59-\u0A5C\u0A5E\u0A66-\u0A75\u0A81-\u0A83\u0A85-\u0A8D\u0A8F-\u0A91\u0A93-\u0AA8\u0AAA-\u0AB0\u0AB2\u0AB3\u0AB5-\u0AB9\u0ABC-\u0AC5\u0AC7-\u0AC9\u0ACB-\u0ACD\u0AD0\u0AE0-\u0AE3\u0AE6-\u0AEF\u0B01-\u0B03\u0B05-\u0B0C\u0B0F\u0B10\u0B13-\u0B28\u0B2A-\u0B30\u0B32\u0B33\u0B35-\u0B39\u0B3C-\u0B44\u0B47\u0B48\u0B4B-\u0B4D\u0B56\u0B57\u0B5C\u0B5D\u0B5F-\u0B63\u0B66-\u0B6F\u0B71\u0B82\u0B83\u0B85-\u0B8A\u0B8E-\u0B90\u0B92-\u0B95\u0B99\u0B9A\u0B9C\u0B9E\u0B9F\u0BA3\u0BA4\u0BA8-\u0BAA\u0BAE-\u0BB9\u0BBE-\u0BC2\u0BC6-\u0BC8\u0BCA-\u0BCD\u0BD0\u0BD7\u0BE6-\u0BEF\u0C00-\u0C03\u0C05-\u0C0C\u0C0E-\u0C10\u0C12-\u0C28\u0C2A-\u0C39\u0C3D-\u0C44\u0C46-\u0C48\u0C4A-\u0C4D\u0C55\u0C56\u0C58\u0C59\u0C60-\u0C63\u0C66-\u0C6F\u0C81-\u0C83\u0C85-\u0C8C\u0C8E-\u0C90\u0C92-\u0CA8\u0CAA-\u0CB3\u0CB5-\u0CB9\u0CBC-\u0CC4\u0CC6-\u0CC8\u0CCA-\u0CCD\u0CD5\u0CD6\u0CDE\u0CE0-\u0CE3\u0CE6-\u0CEF\u0CF1\u0CF2\u0D01-\u0D03\u0D05-\u0D0C\u0D0E-\u0D10\u0D12-\u0D3A\u0D3D-\u0D44\u0D46-\u0D48\u0D4A-\u0D4E\u0D57\u0D60-\u0D63\u0D66-\u0D6F\u0D7A-\u0D7F\u0D82\u0D83\u0D85-\u0D96\u0D9A-\u0DB1\u0DB3-\u0DBB\u0DBD\u0DC0-\u0DC6\u0DCA\u0DCF-\u0DD4\u0DD6\u0DD8-\u0DDF\u0DE6-\u0DEF\u0DF2\u0DF3\u0E01-\u0E3A\u0E40-\u0E4E\u0E50-\u0E59\u0E81\u0E82\u0E84\u0E87\u0E88\u0E8A\u0E8D\u0E94-\u0E97\u0E99-\u0E9F\u0EA1-\u0EA3\u0EA5\u0EA7\u0EAA\u0EAB\u0EAD-\u0EB9\u0EBB-\u0EBD\u0EC0-\u0EC4\u0EC6\u0EC8-\u0ECD\u0ED0-\u0ED9\u0EDC-\u0EDF\u0F00\u0F18\u0F19\u0F20-\u0F29\u0F35\u0F37\u0F39\u0F3E-\u0F47\u0F49-\u0F6C\u0F71-\u0F84\u0F86-\u0F97\u0F99-\u0FBC\u0FC6\u1000-\u1049\u1050-\u109D\u10A0-\u10C5\u10C7\u10CD\u10D0-\u10FA\u10FC-\u1248\u124A-\u124D\u1250-\u1256\u1258\u125A-\u125D\u1260-\u1288\u128A-\u128D\u1290-\u12B0\u12B2-\u12B5\u12B8-\u12BE\u12C0\u12C2-\u12C5\u12C8-\u12D6\u12D8-\u1310\u1312-\u1315\u1318-\u135A\u135D-\u135F\u1380-\u138F\u13A0-\u13F4\u1401-\u166C\u166F-\u167F\u1681-\u169A\u16A0-\u16EA\u16EE-\u16F8\u1700-\u170C\u170E-\u1714\u1720-\u1734\u1740-\u1753\u1760-\u176C\u176E-\u1770\u1772\u1773\u1780-\u17D3\u17D7\u17DC\u17DD\u17E0-\u17E9\u180B-\u180D\u1810-\u1819\u1820-\u1877\u1880-\u18AA\u18B0-\u18F5\u1900-\u191E\u1920-\u192B\u1930-\u193B\u1946-\u196D\u1970-\u1974\u1980-\u19AB\u19B0-\u19C9\u19D0-\u19D9\u1A00-\u1A1B\u1A20-\u1A5E\u1A60-\u1A7C\u1A7F-\u1A89\u1A90-\u1A99\u1AA7\u1AB0-\u1ABD\u1B00-\u1B4B\u1B50-\u1B59\u1B6B-\u1B73\u1B80-\u1BF3\u1C00-\u1C37\u1C40-\u1C49\u1C4D-\u1C7D\u1CD0-\u1CD2\u1CD4-\u1CF6\u1CF8\u1CF9\u1D00-\u1DF5\u1DFC-\u1F15\u1F18-\u1F1D\u1F20-\u1F45\u1F48-\u1F4D\u1F50-\u1F57\u1F59\u1F5B\u1F5D\u1F5F-\u1F7D\u1F80-\u1FB4\u1FB6-\u1FBC\u1FBE\u1FC2-\u1FC4\u1FC6-\u1FCC\u1FD0-\u1FD3\u1FD6-\u1FDB\u1FE0-\u1FEC\u1FF2-\u1FF4\u1FF6-\u1FFC\u200C\u200D\u203F\u2040\u2054\u2071\u207F\u2090-\u209C\u20D0-\u20DC\u20E1\u20E5-\u20F0\u2102\u2107\u210A-\u2113\u2115\u2119-\u211D\u2124\u2126\u2128\u212A-\u212D\u212F-\u2139\u213C-\u213F\u2145-\u2149\u214E\u2160-\u2188\u2C00-\u2C2E\u2C30-\u2C5E\u2C60-\u2CE4\u2CEB-\u2CF3\u2D00-\u2D25\u2D27\u2D2D\u2D30-\u2D67\u2D6F\u2D7F-\u2D96\u2DA0-\u2DA6\u2DA8-\u2DAE\u2DB0-\u2DB6\u2DB8-\u2DBE\u2DC0-\u2DC6\u2DC8-\u2DCE\u2DD0-\u2DD6\u2DD8-\u2DDE\u2DE0-\u2DFF\u2E2F\u3005-\u3007\u3021-\u302F\u3031-\u3035\u3038-\u303C\u3041-\u3096\u3099\u309A\u309D-\u309F\u30A1-\u30FA\u30FC-\u30FF\u3105-\u312D\u3131-\u318E\u31A0-\u31BA\u31F0-\u31FF\u3400-\u4DB5\u4E00-\u9FCC\uA000-\uA48C\uA4D0-\uA4FD\uA500-\uA60C\uA610-\uA62B\uA640-\uA66F\uA674-\uA67D\uA67F-\uA69D\uA69F-\uA6F1\uA717-\uA71F\uA722-\uA788\uA78B-\uA78E\uA790-\uA7AD\uA7B0\uA7B1\uA7F7-\uA827\uA840-\uA873\uA880-\uA8C4\uA8D0-\uA8D9\uA8E0-\uA8F7\uA8FB\uA900-\uA92D\uA930-\uA953\uA960-\uA97C\uA980-\uA9C0\uA9CF-\uA9D9\uA9E0-\uA9FE\uAA00-\uAA36\uAA40-\uAA4D\uAA50-\uAA59\uAA60-\uAA76\uAA7A-\uAAC2\uAADB-\uAADD\uAAE0-\uAAEF\uAAF2-\uAAF6\uAB01-\uAB06\uAB09-\uAB0E\uAB11-\uAB16\uAB20-\uAB26\uAB28-\uAB2E\uAB30-\uAB5A\uAB5C-\uAB5F\uAB64\uAB65\uABC0-\uABEA\uABEC\uABED\uABF0-\uABF9\uAC00-\uD7A3\uD7B0-\uD7C6\uD7CB-\uD7FB\uF900-\uFA6D\uFA70-\uFAD9\uFB00-\uFB06\uFB13-\uFB17\uFB1D-\uFB28\uFB2A-\uFB36\uFB38-\uFB3C\uFB3E\uFB40\uFB41\uFB43\uFB44\uFB46-\uFBB1\uFBD3-\uFD3D\uFD50-\uFD8F\uFD92-\uFDC7\uFDF0-\uFDFB\uFE00-\uFE0F\uFE20-\uFE2D\uFE33\uFE34\uFE4D-\uFE4F\uFE70-\uFE74\uFE76-\uFEFC\uFF10-\uFF19\uFF21-\uFF3A\uFF3F\uFF41-\uFF5A\uFF66-\uFFBE\uFFC2-\uFFC7\uFFCA-\uFFCF\uFFD2-\uFFD7\uFFDA-\uFFDC]');

      return (ch === 36) || (ch === 95) ||  // $ (dollar) and _ (underscore)
        (ch >= 65 && ch <= 90) ||         // A..Z
        (ch >= 97 && ch <= 122) ||        // a..z
        (ch >= 48 && ch <= 57) ||         // 0..9
        (ch === 92) ||                    // \ (backslash)
        ((ch >= 0x80) && NonAsciiIdentifierPart.test(String.fromCharCode(ch)));
    }

    function parseIdentityEscape() {
      // IdentityEscape ::
      //      SourceCharacter but not IdentifierPart
      //      <ZWJ>
      //      <ZWNJ>

      var ZWJ = '\u200C';
      var ZWNJ = '\u200D';

      var res;
      var tmp;

      if (!isIdentifierPart(lookahead())) {
        tmp = incr();
        return createEscaped('identifier', tmp.charCodeAt(0), tmp, 1);
      }

      if (match(ZWJ)) {
        // <ZWJ>
        return createEscaped('identifier', 0x200C, ZWJ);
      } else if (match(ZWNJ)) {
        // <ZWNJ>
        return createEscaped('identifier', 0x200D, ZWNJ);
      }

      return null;
    }

    function parseCharacterClass() {
      // CharacterClass ::
      //      [ [lookahead ∉ {^}] ClassRanges ]
      //      [ ^ ClassRanges ]

      var res, from = pos;
      if (res = matchReg(/^\[\^/)) {
        res = parseClassRanges();
        skip(']');
        return createCharacterClass(res, true, from, pos);
      } else if (match('[')) {
        res = parseClassRanges();
        skip(']');
        return createCharacterClass(res, false, from, pos);
      }

      return null;
    }

    function parseClassRanges() {
      // ClassRanges ::
      //      [empty]
      //      NonemptyClassRanges

      var res;
      if (current(']')) {
        // Empty array means nothing insinde of the ClassRange.
        return [];
      } else {
        res = parseNonemptyClassRanges();
        if (!res) {
          throw SyntaxError('nonEmptyClassRanges');
        }
        return res;
      }
    }

    function parseHelperClassRanges(atom) {
      var from, to, res;
      if (current('-') && !next(']')) {
        // ClassAtom - ClassAtom ClassRanges
        skip('-');

        res = parseClassAtom();
        if (!res) {
          throw SyntaxError('classAtom');
        }
        to = pos;
        var classRanges = parseClassRanges();
        if (!classRanges) {
          throw SyntaxError('classRanges');
        }
        from = atom.range[0];
        if (classRanges.type === 'empty') {
          return [createClassRange(atom, res, from, to)];
        }
        return [createClassRange(atom, res, from, to)].concat(classRanges);
      }

      res = parseNonemptyClassRangesNoDash();
      if (!res) {
        throw SyntaxError('nonEmptyClassRangesNoDash');
      }

      return [atom].concat(res);
    }

    function parseNonemptyClassRanges() {
      // NonemptyClassRanges ::
      //      ClassAtom
      //      ClassAtom NonemptyClassRangesNoDash
      //      ClassAtom - ClassAtom ClassRanges

      var atom = parseClassAtom();
      if (!atom) {
        throw SyntaxError('classAtom');
      }

      if (current(']')) {
        // ClassAtom
        return [atom];
      }

      // ClassAtom NonemptyClassRangesNoDash
      // ClassAtom - ClassAtom ClassRanges
      return parseHelperClassRanges(atom);
    }

    function parseNonemptyClassRangesNoDash() {
      // NonemptyClassRangesNoDash ::
      //      ClassAtom
      //      ClassAtomNoDash NonemptyClassRangesNoDash
      //      ClassAtomNoDash - ClassAtom ClassRanges

      var res = parseClassAtom();
      if (!res) {
        throw SyntaxError('classAtom');
      }
      if (current(']')) {
        //      ClassAtom
        return res;
      }

      // ClassAtomNoDash NonemptyClassRangesNoDash
      // ClassAtomNoDash - ClassAtom ClassRanges
      return parseHelperClassRanges(res);
    }

    function parseClassAtom() {
      // ClassAtom ::
      //      -
      //      ClassAtomNoDash
      if (match('-')) {
        return createCharacter('-');
      } else {
        return parseClassAtomNoDash();
      }
    }

    function parseClassAtomNoDash() {
      // ClassAtomNoDash ::
      //      SourceCharacter but not one of \ or ] or -
      //      \ ClassEscape

      var res;
      if (res = matchReg(/^[^\\\]-]/)) {
        return createCharacter(res[0]);
      } else if (match('\\')) {
        res = parseClassEscape();
        if (!res) {
          throw SyntaxError('classEscape');
        }

        return parseUnicodeSurrogatePairEscape(res);
      }
    }

    var backrefDenied = [];
    var closedCaptureCounter = 0;
    var firstIteration = true;
    var hasUnicodeFlag = (flags || "").indexOf("u") !== -1;
    var pos = 0;

    // Convert the input to a string and treat the empty string special.
    str = String(str);
    if (str === '') {
      str = '(?:)';
    }

    var result = parseDisjunction();

    if (result.range[1] !== str.length) {
      throw SyntaxError('Could not parse entire input - got stuck: ' + str);
    }

    // The spec requires to interpret the `\2` in `/\2()()/` as backreference.
    // As the parser collects the number of capture groups as the string is
    // parsed it is impossible to make these decisions at the point the `\2` is
    // handled. In case the local decision turns out to be wrongq after the
    // parsing has finished, the input string is parsed a second time with the
    // total count of capture groups set.
    //
    // SEE: https://github.com/jviereck/regjsparser/issues/70
    for (var i = 0; i < backrefDenied.length; i++) {
      if (backrefDenied[i] <= closedCaptureCounter) {
        // Parse the input a second time.
        pos = 0;
        firstIteration = false;
        return parseDisjunction();
      }
    }

    return result;
  };

  var regjsparser = {
    parse: parse
  };

  if (typeof module !== 'undefined' && module.exports) {
    module.exports = regjsparser;
  } else {
    window.regjsparser = regjsparser;
  }

}());
