// 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 ) // ( ? < = Disjunction ) // ( ? < ! Disjunction ) //

// Quantifier

// QuantifierPrefix // QuantifierPrefix ? //

// QuantifierPrefix

// * // + // ? // { DecimalDigits } // { DecimalDigits , } // { DecimalDigits , DecimalDigits } //

// Atom

// PatternCharacter // . // \ AtomEscape // CharacterClass // ( GroupSpecifier Disjunction ) // ( ? : Disjunction ) //

// PatternCharacter

// SourceCharacter but not any of: ^ $ \ . * + ? ( ) [ ] { } | //

// AtomEscape

// DecimalEscape // CharacterEscape // CharacterClassEscape // k GroupName //

// CharacterEscape

// ControlEscape // c ControlLetter // HexEscapeSequence // RegExpUnicodeEscapeSequence (ES6) // IdentityEscape //

// 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 c //

// 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 //

// GroupSpecifier

// [empty] // ? GroupName //

// GroupName

// < RegExpIdentifierName > //

// RegExpIdentifierName

// RegExpIdentifierStart // RegExpIdentifierName RegExpIdentifierContinue //

// RegExpIdentifierStart

// UnicodeIDStart // $ // _ // \ RegExpUnicodeEscapeSequence //

// RegExpIdentifierContinue

// UnicodeIDContinue // $ // _ // \ RegExpUnicodeEscapeSequence // <ZWNJ> // <ZWJ>

(function() {

var fromCodePoint = String.fromCodePoint || (function() {
  // Implementation taken from
  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/fromCodePoint

  var stringFromCharCode = String.fromCharCode;
  var floor = Math.floor;

  return function fromCodePoint() {
    var MAX_SIZE = 0x4000;
    var codeUnits = [];
    var highSurrogate;
    var lowSurrogate;
    var index = -1;
    var length = arguments.length;
    if (!length) {
      return '';
    }
    var result = '';
    while (++index < length) {
      var codePoint = Number(arguments[index]);
      if (
        !isFinite(codePoint) ||       // `NaN`, `+Infinity`, or `-Infinity`
        codePoint < 0 ||              // not a valid Unicode code point
        codePoint > 0x10FFFF ||       // not a valid Unicode code point
        floor(codePoint) != codePoint // not an integer
      ) {
        throw RangeError('Invalid code point: ' + codePoint);
      }
      if (codePoint <= 0xFFFF) { // BMP code point
        codeUnits.push(codePoint);
      } else { // Astral code point; split in surrogate halves
        // http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
        codePoint -= 0x10000;
        highSurrogate = (codePoint >> 10) + 0xD800;
        lowSurrogate = (codePoint % 0x400) + 0xDC00;
        codeUnits.push(highSurrogate, lowSurrogate);
      }
      if (index + 1 == length || codeUnits.length > MAX_SIZE) {
        result += stringFromCharCode.apply(null, codeUnits);
        codeUnits.length = 0;
      }
    }
    return result;
  };
}());

function parse(str, flags, features) {
  if (!features) {
    features = {};
  }
  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 createNamedReference(name) {
    return addRaw({
      type: 'reference',
      name: name,
      range: [
        name.range[0] - 3,
        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) {
      bail('invalid range in character class', min.raw + '-' + max.raw, from, to);
    }

    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)) {
      bail('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) {
      bail('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;
    }

    return finishGroup(type, from);
  }

  function finishGroup(type, from) {
    var body = parseDisjunction();
    if (!body) {
      bail('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, from = pos;
    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) {
        bail('numbers out of order in {} quantifier', '', from, pos);
      }
      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
    //      ( GroupSpecifier 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) {
        if (!hasUnicodeFlag && lookahead() == 'c') {
          // B.1.4 ExtendedAtom
          // \[lookahead = c]
          return createValue('symbol', 92, pos - 1, pos);
        }
        bail('atomEscape');
      }
      return res;
    }
    else if (res = parseCharacterClass()) {
      return res;
    }
    else if (features.lookbehind && (res = parseGroup('(?<=', 'lookbehind', '(?<!', 'negativeLookbehind'))) {
      return res;
    }
    else if (features.namedGroups && match("(?<")) {
      var name = parseIdentifier();
      skip(">");
      var group = finishGroup("normal", name.range[0] - 3);
      group.name = name;
      return group;
    }
    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
    //      k GroupName

    var res, from = pos;

    res = parseDecimalEscape() || parseNamedReference();
    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')) {
        bail('\\B not possible inside of CharacterClass', '', from);
      } else if (!hasUnicodeFlag && (res = matchReg(/^c([0-9])/))) {
        // B.1.4
        // c ClassControlLetter
        return createEscaped('controlLetter', res[1] + 16, res[1], 2);
      }
    }

    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 parseNamedReference() {
    if (features.namedGroups && matchReg(/^k<(?=.*?>)/)) {
      var name = parseIdentifier();
      skip('>');
      return createNamedReference(name);
    }
  }

  function parseRegExpUnicodeEscapeSequence() {
    var res;
    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);
    }
  }

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

    var res;
    var from = pos;
    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 = parseRegExpUnicodeEscapeSequence()) {
      if (!res || res.codePoint > 0x10FFFF) {
        bail('Invalid escape sequence', null, from, pos);
      }
      return res;
    } else if (features.unicodePropertyEscape && hasUnicodeFlag && (res = matchReg(/^([pP])\{([^\}]+)\}/))) {
      // https://github.com/jviereck/regjsparser/issues/77
      return addRaw({
        type: 'unicodePropertyEscape',
        negative: res[1] === 'P',
        value: res[2],
        range: [res.range[0] - 1, res.range[1]],
        raw: res[0]
      });
    } else {
      // IdentityEscape
      return parseIdentityEscape();
    }
  }

  function parseIdentifierAtom(check) {
    var ch = lookahead();
    var from = pos;
    if (ch === '\\') {
      incr();
      var esc = parseRegExpUnicodeEscapeSequence();
      if (!esc || !check(esc.codePoint)) {
        bail('Invalid escape sequence', null, from, pos);
      }
      return fromCodePoint(esc.codePoint);
    }
    var code = ch.charCodeAt(0);
    if (code >= 0xD800 && code <= 0xDBFF) {
      ch += str[pos + 1];
      var second = ch.charCodeAt(1);
      if (second >= 0xDC00 && second <= 0xDFFF) {
        // Unicode surrogate pair
        code = (code - 0xD800) * 0x400 + second - 0xDC00 + 0x10000;
      }
    }
    if (!check(code)) return;
    incr();
    if (code > 0xFFFF) incr();
    return ch;
  }

  function parseIdentifier() {
    // RegExpIdentifierName ::
    //      RegExpIdentifierStart
    //      RegExpIdentifierName RegExpIdentifierContinue
    //
    // RegExpIdentifierStart ::
    //      UnicodeIDStart
    //      $
    //      _
    //      \ RegExpUnicodeEscapeSequence
    //
    // RegExpIdentifierContinue ::
    //      UnicodeIDContinue
    //      $
    //      _
    //      \ RegExpUnicodeEscapeSequence
    //      <ZWNJ>
    //      <ZWJ>

    var start = pos;
    var res = parseIdentifierAtom(isIdentifierStart);
    if (!res) {
      bail('Invalid identifier');
    }

    var ch;
    while (ch = parseIdentifierAtom(isIdentifierPart)) {
      res += ch;
    }

    return addRaw({
      type: 'identifier',
      value: res,
      range: [start, pos]
    });
  }

  function isIdentifierStart(ch) {
    // Generated by `tools/generate-identifier-regex.js`.
    var NonAsciiIdentifierStart = /[\$A-Z_a-z\xAA\xB5\xBA\xC0-\xD6\xD8-\xF6\xF8-\u02C1\u02C6-\u02D1\u02E0-\u02E4\u02EC\u02EE\u0370-\u0374\u0376\u0377\u037A-\u037D\u037F\u0386\u0388-\u038A\u038C\u038E-\u03A1\u03A3-\u03F5\u03F7-\u0481\u048A-\u052F\u0531-\u0556\u0559\u0560-\u0588\u05D0-\u05EA\u05EF-\u05F2\u0620-\u064A\u066E\u066F\u0671-\u06D3\u06D5\u06E5\u06E6\u06EE\u06EF\u06FA-\u06FC\u06FF\u0710\u0712-\u072F\u074D-\u07A5\u07B1\u07CA-\u07EA\u07F4\u07F5\u07FA\u0800-\u0815\u081A\u0824\u0828\u0840-\u0858\u0860-\u086A\u08A0-\u08B4\u08B6-\u08BD\u0904-\u0939\u093D\u0950\u0958-\u0961\u0971-\u0980\u0985-\u098C\u098F\u0990\u0993-\u09A8\u09AA-\u09B0\u09B2\u09B6-\u09B9\u09BD\u09CE\u09DC\u09DD\u09DF-\u09E1\u09F0\u09F1\u09FC\u0A05-\u0A0A\u0A0F\u0A10\u0A13-\u0A28\u0A2A-\u0A30\u0A32\u0A33\u0A35\u0A36\u0A38\u0A39\u0A59-\u0A5C\u0A5E\u0A72-\u0A74\u0A85-\u0A8D\u0A8F-\u0A91\u0A93-\u0AA8\u0AAA-\u0AB0\u0AB2\u0AB3\u0AB5-\u0AB9\u0ABD\u0AD0\u0AE0\u0AE1\u0AF9\u0B05-\u0B0C\u0B0F\u0B10\u0B13-\u0B28\u0B2A-\u0B30\u0B32\u0B33\u0B35-\u0B39\u0B3D\u0B5C\u0B5D\u0B5F-\u0B61\u0B71\u0B83\u0B85-\u0B8A\u0B8E-\u0B90\u0B92-\u0B95\u0B99\u0B9A\u0B9C\u0B9E\u0B9F\u0BA3\u0BA4\u0BA8-\u0BAA\u0BAE-\u0BB9\u0BD0\u0C05-\u0C0C\u0C0E-\u0C10\u0C12-\u0C28\u0C2A-\u0C39\u0C3D\u0C58-\u0C5A\u0C60\u0C61\u0C80\u0C85-\u0C8C\u0C8E-\u0C90\u0C92-\u0CA8\u0CAA-\u0CB3\u0CB5-\u0CB9\u0CBD\u0CDE\u0CE0\u0CE1\u0CF1\u0CF2\u0D05-\u0D0C\u0D0E-\u0D10\u0D12-\u0D3A\u0D3D\u0D4E\u0D54-\u0D56\u0D5F-\u0D61\u0D7A-\u0D7F\u0D85-\u0D96\u0D9A-\u0DB1\u0DB3-\u0DBB\u0DBD\u0DC0-\u0DC6\u0E01-\u0E30\u0E32\u0E33\u0E40-\u0E46\u0E81\u0E82\u0E84\u0E87\u0E88\u0E8A\u0E8D\u0E94-\u0E97\u0E99-\u0E9F\u0EA1-\u0EA3\u0EA5\u0EA7\u0EAA\u0EAB\u0EAD-\u0EB0\u0EB2\u0EB3\u0EBD\u0EC0-\u0EC4\u0EC6\u0EDC-\u0EDF\u0F00\u0F40-\u0F47\u0F49-\u0F6C\u0F88-\u0F8C\u1000-\u102A\u103F\u1050-\u1055\u105A-\u105D\u1061\u1065\u1066\u106E-\u1070\u1075-\u1081\u108E\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\u1380-\u138F\u13A0-\u13F5\u13F8-\u13FD\u1401-\u166C\u166F-\u167F\u1681-\u169A\u16A0-\u16EA\u16EE-\u16F8\u1700-\u170C\u170E-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176C\u176E-\u1770\u1780-\u17B3\u17D7\u17DC\u1820-\u1878\u1880-\u18A8\u18AA\u18B0-\u18F5\u1900-\u191E\u1950-\u196D\u1970-\u1974\u1980-\u19AB\u19B0-\u19C9\u1A00-\u1A16\u1A20-\u1A54\u1AA7\u1B05-\u1B33\u1B45-\u1B4B\u1B83-\u1BA0\u1BAE\u1BAF\u1BBA-\u1BE5\u1C00-\u1C23\u1C4D-\u1C4F\u1C5A-\u1C7D\u1C80-\u1C88\u1C90-\u1CBA\u1CBD-\u1CBF\u1CE9-\u1CEC\u1CEE-\u1CF1\u1CF5\u1CF6\u1D00-\u1DBF\u1E00-\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\u2071\u207F\u2090-\u209C\u2102\u2107\u210A-\u2113\u2115\u2118-\u211D\u2124\u2126\u2128\u212A-\u2139\u213C-\u213F\u2145-\u2149\u214E\u2160-\u2188\u2C00-\u2C2E\u2C30-\u2C5E\u2C60-\u2CE4\u2CEB-\u2CEE\u2CF2\u2CF3\u2D00-\u2D25\u2D27\u2D2D\u2D30-\u2D67\u2D6F\u2D80-\u2D96\u2DA0-\u2DA6\u2DA8-\u2DAE\u2DB0-\u2DB6\u2DB8-\u2DBE\u2DC0-\u2DC6\u2DC8-\u2DCE\u2DD0-\u2DD6\u2DD8-\u2DDE\u3005-\u3007\u3021-\u3029\u3031-\u3035\u3038-\u303C\u3041-\u3096\u309B-\u309F\u30A1-\u30FA\u30FC-\u30FF\u3105-\u312F\u3131-\u318E\u31A0-\u31BA\u31F0-\u31FF\u3400-\u4DB5\u4E00-\u9FEF\uA000-\uA48C\uA4D0-\uA4FD\uA500-\uA60C\uA610-\uA61F\uA62A\uA62B\uA640-\uA66E\uA67F-\uA69D\uA6A0-\uA6EF\uA717-\uA71F\uA722-\uA788\uA78B-\uA7B9\uA7F7-\uA801\uA803-\uA805\uA807-\uA80A\uA80C-\uA822\uA840-\uA873\uA882-\uA8B3\uA8F2-\uA8F7\uA8FB\uA8FD\uA8FE\uA90A-\uA925\uA930-\uA946\uA960-\uA97C\uA984-\uA9B2\uA9CF\uA9E0-\uA9E4\uA9E6-\uA9EF\uA9FA-\uA9FE\uAA00-\uAA28\uAA40-\uAA42\uAA44-\uAA4B\uAA60-\uAA76\uAA7A\uAA7E-\uAAAF\uAAB1\uAAB5\uAAB6\uAAB9-\uAABD\uAAC0\uAAC2\uAADB-\uAADD\uAAE0-\uAAEA\uAAF2-\uAAF4\uAB01-\uAB06\uAB09-\uAB0E\uAB11-\uAB16\uAB20-\uAB26\uAB28-\uAB2E\uAB30-\uAB5A\uAB5C-\uAB65\uAB70-\uABE2\uAC00-\uD7A3\uD7B0-\uD7C6\uD7CB-\uD7FB\uF900-\uFA6D\uFA70-\uFAD9\uFB00-\uFB06\uFB13-\uFB17\uFB1D\uFB1F-\uFB28\uFB2A-\uFB36\uFB38-\uFB3C\uFB3E\uFB40\uFB41\uFB43\uFB44\uFB46-\uFBB1\uFBD3-\uFD3D\uFD50-\uFD8F\uFD92-\uFDC7\uFDF0-\uFDFB\uFE70-\uFE74\uFE76-\uFEFC\uFF21-\uFF3A\uFF41-\uFF5A\uFF66-\uFFBE\uFFC2-\uFFC7\uFFCA-\uFFCF\uFFD2-\uFFD7\uFFDA-\uFFDC]|\uD800[\uDC00-\uDC0B\uDC0D-\uDC26\uDC28-\uDC3A\uDC3C\uDC3D\uDC3F-\uDC4D\uDC50-\uDC5D\uDC80-\uDCFA\uDD40-\uDD74\uDE80-\uDE9C\uDEA0-\uDED0\uDF00-\uDF1F\uDF2D-\uDF4A\uDF50-\uDF75\uDF80-\uDF9D\uDFA0-\uDFC3\uDFC8-\uDFCF\uDFD1-\uDFD5]|\uD801[\uDC00-\uDC9D\uDCB0-\uDCD3\uDCD8-\uDCFB\uDD00-\uDD27\uDD30-\uDD63\uDE00-\uDF36\uDF40-\uDF55\uDF60-\uDF67]|\uD802[\uDC00-\uDC05\uDC08\uDC0A-\uDC35\uDC37\uDC38\uDC3C\uDC3F-\uDC55\uDC60-\uDC76\uDC80-\uDC9E\uDCE0-\uDCF2\uDCF4\uDCF5\uDD00-\uDD15\uDD20-\uDD39\uDD80-\uDDB7\uDDBE\uDDBF\uDE00\uDE10-\uDE13\uDE15-\uDE17\uDE19-\uDE35\uDE60-\uDE7C\uDE80-\uDE9C\uDEC0-\uDEC7\uDEC9-\uDEE4\uDF00-\uDF35\uDF40-\uDF55\uDF60-\uDF72\uDF80-\uDF91]|\uD803[\uDC00-\uDC48\uDC80-\uDCB2\uDCC0-\uDCF2\uDD00-\uDD23\uDF00-\uDF1C\uDF27\uDF30-\uDF45]|\uD804[\uDC03-\uDC37\uDC83-\uDCAF\uDCD0-\uDCE8\uDD03-\uDD26\uDD44\uDD50-\uDD72\uDD76\uDD83-\uDDB2\uDDC1-\uDDC4\uDDDA\uDDDC\uDE00-\uDE11\uDE13-\uDE2B\uDE80-\uDE86\uDE88\uDE8A-\uDE8D\uDE8F-\uDE9D\uDE9F-\uDEA8\uDEB0-\uDEDE\uDF05-\uDF0C\uDF0F\uDF10\uDF13-\uDF28\uDF2A-\uDF30\uDF32\uDF33\uDF35-\uDF39\uDF3D\uDF50\uDF5D-\uDF61]|\uD805[\uDC00-\uDC34\uDC47-\uDC4A\uDC80-\uDCAF\uDCC4\uDCC5\uDCC7\uDD80-\uDDAE\uDDD8-\uDDDB\uDE00-\uDE2F\uDE44\uDE80-\uDEAA\uDF00-\uDF1A]|\uD806[\uDC00-\uDC2B\uDCA0-\uDCDF\uDCFF\uDE00\uDE0B-\uDE32\uDE3A\uDE50\uDE5C-\uDE83\uDE86-\uDE89\uDE9D\uDEC0-\uDEF8]|\uD807[\uDC00-\uDC08\uDC0A-\uDC2E\uDC40\uDC72-\uDC8F\uDD00-\uDD06\uDD08\uDD09\uDD0B-\uDD30\uDD46\uDD60-\uDD65\uDD67\uDD68\uDD6A-\uDD89\uDD98\uDEE0-\uDEF2]|\uD808[\uDC00-\uDF99]|\uD809[\uDC00-\uDC6E\uDC80-\uDD43]|[\uD80C\uD81C-\uD820\uD840-\uD868\uD86A-\uD86C\uD86F-\uD872\uD874-\uD879][\uDC00-\uDFFF]|\uD80D[\uDC00-\uDC2E]|\uD811[\uDC00-\uDE46]|\uD81A[\uDC00-\uDE38\uDE40-\uDE5E\uDED0-\uDEED\uDF00-\uDF2F\uDF40-\uDF43\uDF63-\uDF77\uDF7D-\uDF8F]|\uD81B[\uDE40-\uDE7F\uDF00-\uDF44\uDF50\uDF93-\uDF9F\uDFE0\uDFE1]|\uD821[\uDC00-\uDFF1]|\uD822[\uDC00-\uDEF2]|\uD82C[\uDC00-\uDD1E\uDD70-\uDEFB]|\uD82F[\uDC00-\uDC6A\uDC70-\uDC7C\uDC80-\uDC88\uDC90-\uDC99]|\uD835[\uDC00-\uDC54\uDC56-\uDC9C\uDC9E\uDC9F\uDCA2\uDCA5\uDCA6\uDCA9-\uDCAC\uDCAE-\uDCB9\uDCBB\uDCBD-\uDCC3\uDCC5-\uDD05\uDD07-\uDD0A\uDD0D-\uDD14\uDD16-\uDD1C\uDD1E-\uDD39\uDD3B-\uDD3E\uDD40-\uDD44\uDD46\uDD4A-\uDD50\uDD52-\uDEA5\uDEA8-\uDEC0\uDEC2-\uDEDA\uDEDC-\uDEFA\uDEFC-\uDF14\uDF16-\uDF34\uDF36-\uDF4E\uDF50-\uDF6E\uDF70-\uDF88\uDF8A-\uDFA8\uDFAA-\uDFC2\uDFC4-\uDFCB]|\uD83A[\uDC00-\uDCC4\uDD00-\uDD43]|\uD83B[\uDE00-\uDE03\uDE05-\uDE1F\uDE21\uDE22\uDE24\uDE27\uDE29-\uDE32\uDE34-\uDE37\uDE39\uDE3B\uDE42\uDE47\uDE49\uDE4B\uDE4D-\uDE4F\uDE51\uDE52\uDE54\uDE57\uDE59\uDE5B\uDE5D\uDE5F\uDE61\uDE62\uDE64\uDE67-\uDE6A\uDE6C-\uDE72\uDE74-\uDE77\uDE79-\uDE7C\uDE7E\uDE80-\uDE89\uDE8B-\uDE9B\uDEA1-\uDEA3\uDEA5-\uDEA9\uDEAB-\uDEBB]|\uD869[\uDC00-\uDED6\uDF00-\uDFFF]|\uD86D[\uDC00-\uDF34\uDF40-\uDFFF]|\uD86E[\uDC00-\uDC1D\uDC20-\uDFFF]|\uD873[\uDC00-\uDEA1\uDEB0-\uDFFF]|\uD87A[\uDC00-\uDFE0]|\uD87E[\uDC00-\uDE1D]/;

    return (ch === 36) || (ch === 95) ||  // $ (dollar) and _ (underscore)
      (ch >= 65 && ch <= 90) ||         // A..Z
      (ch >= 97 && ch <= 122) ||        // a..z
      ((ch >= 0x80) && NonAsciiIdentifierStart.test(fromCodePoint(ch)));
  }

  // Taken from the Esprima parser.
  function isIdentifierPart(ch) {
    // Generated by `tools/generate-identifier-regex.js`.
    var NonAsciiIdentifierPartOnly = /[0-9_\xB7\u0300-\u036F\u0387\u0483-\u0487\u0591-\u05BD\u05BF\u05C1\u05C2\u05C4\u05C5\u05C7\u0610-\u061A\u064B-\u0669\u0670\u06D6-\u06DC\u06DF-\u06E4\u06E7\u06E8\u06EA-\u06ED\u06F0-\u06F9\u0711\u0730-\u074A\u07A6-\u07B0\u07C0-\u07C9\u07EB-\u07F3\u07FD\u0816-\u0819\u081B-\u0823\u0825-\u0827\u0829-\u082D\u0859-\u085B\u08D3-\u08E1\u08E3-\u0903\u093A-\u093C\u093E-\u094F\u0951-\u0957\u0962\u0963\u0966-\u096F\u0981-\u0983\u09BC\u09BE-\u09C4\u09C7\u09C8\u09CB-\u09CD\u09D7\u09E2\u09E3\u09E6-\u09EF\u09FE\u0A01-\u0A03\u0A3C\u0A3E-\u0A42\u0A47\u0A48\u0A4B-\u0A4D\u0A51\u0A66-\u0A71\u0A75\u0A81-\u0A83\u0ABC\u0ABE-\u0AC5\u0AC7-\u0AC9\u0ACB-\u0ACD\u0AE2\u0AE3\u0AE6-\u0AEF\u0AFA-\u0AFF\u0B01-\u0B03\u0B3C\u0B3E-\u0B44\u0B47\u0B48\u0B4B-\u0B4D\u0B56\u0B57\u0B62\u0B63\u0B66-\u0B6F\u0B82\u0BBE-\u0BC2\u0BC6-\u0BC8\u0BCA-\u0BCD\u0BD7\u0BE6-\u0BEF\u0C00-\u0C04\u0C3E-\u0C44\u0C46-\u0C48\u0C4A-\u0C4D\u0C55\u0C56\u0C62\u0C63\u0C66-\u0C6F\u0C81-\u0C83\u0CBC\u0CBE-\u0CC4\u0CC6-\u0CC8\u0CCA-\u0CCD\u0CD5\u0CD6\u0CE2\u0CE3\u0CE6-\u0CEF\u0D00-\u0D03\u0D3B\u0D3C\u0D3E-\u0D44\u0D46-\u0D48\u0D4A-\u0D4D\u0D57\u0D62\u0D63\u0D66-\u0D6F\u0D82\u0D83\u0DCA\u0DCF-\u0DD4\u0DD6\u0DD8-\u0DDF\u0DE6-\u0DEF\u0DF2\u0DF3\u0E31\u0E34-\u0E3A\u0E47-\u0E4E\u0E50-\u0E59\u0EB1\u0EB4-\u0EB9\u0EBB\u0EBC\u0EC8-\u0ECD\u0ED0-\u0ED9\u0F18\u0F19\u0F20-\u0F29\u0F35\u0F37\u0F39\u0F3E\u0F3F\u0F71-\u0F84\u0F86\u0F87\u0F8D-\u0F97\u0F99-\u0FBC\u0FC6\u102B-\u103E\u1040-\u1049\u1056-\u1059\u105E-\u1060\u1062-\u1064\u1067-\u106D\u1071-\u1074\u1082-\u108D\u108F-\u109D\u135D-\u135F\u1369-\u1371\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17B4-\u17D3\u17DD\u17E0-\u17E9\u180B-\u180D\u1810-\u1819\u18A9\u1920-\u192B\u1930-\u193B\u1946-\u194F\u19D0-\u19DA\u1A17-\u1A1B\u1A55-\u1A5E\u1A60-\u1A7C\u1A7F-\u1A89\u1A90-\u1A99\u1AB0-\u1ABD\u1B00-\u1B04\u1B34-\u1B44\u1B50-\u1B59\u1B6B-\u1B73\u1B80-\u1B82\u1BA1-\u1BAD\u1BB0-\u1BB9\u1BE6-\u1BF3\u1C24-\u1C37\u1C40-\u1C49\u1C50-\u1C59\u1CD0-\u1CD2\u1CD4-\u1CE8\u1CED\u1CF2-\u1CF4\u1CF7-\u1CF9\u1DC0-\u1DF9\u1DFB-\u1DFF\u200C\u200D\u203F\u2040\u2054\u20D0-\u20DC\u20E1\u20E5-\u20F0\u2CEF-\u2CF1\u2D7F\u2DE0-\u2DFF\u302A-\u302F\u3099\u309A\uA620-\uA629\uA66F\uA674-\uA67D\uA69E\uA69F\uA6F0\uA6F1\uA802\uA806\uA80B\uA823-\uA827\uA880\uA881\uA8B4-\uA8C5\uA8D0-\uA8D9\uA8E0-\uA8F1\uA8FF-\uA909\uA926-\uA92D\uA947-\uA953\uA980-\uA983\uA9B3-\uA9C0\uA9D0-\uA9D9\uA9E5\uA9F0-\uA9F9\uAA29-\uAA36\uAA43\uAA4C\uAA4D\uAA50-\uAA59\uAA7B-\uAA7D\uAAB0\uAAB2-\uAAB4\uAAB7\uAAB8\uAABE\uAABF\uAAC1\uAAEB-\uAAEF\uAAF5\uAAF6\uABE3-\uABEA\uABEC\uABED\uABF0-\uABF9\uFB1E\uFE00-\uFE0F\uFE20-\uFE2F\uFE33\uFE34\uFE4D-\uFE4F\uFF10-\uFF19\uFF3F]|\uD800[\uDDFD\uDEE0\uDF76-\uDF7A]|\uD801[\uDCA0-\uDCA9]|\uD802[\uDE01-\uDE03\uDE05\uDE06\uDE0C-\uDE0F\uDE38-\uDE3A\uDE3F\uDEE5\uDEE6]|\uD803[\uDD24-\uDD27\uDD30-\uDD39\uDF46-\uDF50]|\uD804[\uDC00-\uDC02\uDC38-\uDC46\uDC66-\uDC6F\uDC7F-\uDC82\uDCB0-\uDCBA\uDCF0-\uDCF9\uDD00-\uDD02\uDD27-\uDD34\uDD36-\uDD3F\uDD45\uDD46\uDD73\uDD80-\uDD82\uDDB3-\uDDC0\uDDC9-\uDDCC\uDDD0-\uDDD9\uDE2C-\uDE37\uDE3E\uDEDF-\uDEEA\uDEF0-\uDEF9\uDF00-\uDF03\uDF3B\uDF3C\uDF3E-\uDF44\uDF47\uDF48\uDF4B-\uDF4D\uDF57\uDF62\uDF63\uDF66-\uDF6C\uDF70-\uDF74]|\uD805[\uDC35-\uDC46\uDC50-\uDC59\uDC5E\uDCB0-\uDCC3\uDCD0-\uDCD9\uDDAF-\uDDB5\uDDB8-\uDDC0\uDDDC\uDDDD\uDE30-\uDE40\uDE50-\uDE59\uDEAB-\uDEB7\uDEC0-\uDEC9\uDF1D-\uDF2B\uDF30-\uDF39]|\uD806[\uDC2C-\uDC3A\uDCE0-\uDCE9\uDE01-\uDE0A\uDE33-\uDE39\uDE3B-\uDE3E\uDE47\uDE51-\uDE5B\uDE8A-\uDE99]|\uD807[\uDC2F-\uDC36\uDC38-\uDC3F\uDC50-\uDC59\uDC92-\uDCA7\uDCA9-\uDCB6\uDD31-\uDD36\uDD3A\uDD3C\uDD3D\uDD3F-\uDD45\uDD47\uDD50-\uDD59\uDD8A-\uDD8E\uDD90\uDD91\uDD93-\uDD97\uDDA0-\uDDA9\uDEF3-\uDEF6]|\uD81A[\uDE60-\uDE69\uDEF0-\uDEF4\uDF30-\uDF36\uDF50-\uDF59]|\uD81B[\uDF51-\uDF7E\uDF8F-\uDF92]|\uD82F[\uDC9D\uDC9E]|\uD834[\uDD65-\uDD69\uDD6D-\uDD72\uDD7B-\uDD82\uDD85-\uDD8B\uDDAA-\uDDAD\uDE42-\uDE44]|\uD835[\uDFCE-\uDFFF]|\uD836[\uDE00-\uDE36\uDE3B-\uDE6C\uDE75\uDE84\uDE9B-\uDE9F\uDEA1-\uDEAF]|\uD838[\uDC00-\uDC06\uDC08-\uDC18\uDC1B-\uDC21\uDC23\uDC24\uDC26-\uDC2A]|\uD83A[\uDCD0-\uDCD6\uDD44-\uDD4A\uDD50-\uDD59]|\uDB40[\uDD00-\uDDEF]/;

    return isIdentifierStart(ch) ||
      (ch >= 48 && ch <= 57) ||         // 0..9
      ((ch >= 0x80) && NonAsciiIdentifierPartOnly.test(fromCodePoint(ch)));
  }

  function parseIdentityEscape() {
    // IdentityEscape ::
    //      SourceCharacter but not c

    var tmp;

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

    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) {
        bail('nonEmptyClassRanges');
      }
      return res;
    }
  }

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

      res = parseClassAtom();
      if (!res) {
        bail('classAtom');
      }
      to = pos;
      var classRanges = parseClassRanges();
      if (!classRanges) {
        bail('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) {
      bail('nonEmptyClassRangesNoDash');
    }

    return [atom].concat(res);
  }

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

    var atom = parseClassAtom();
    if (!atom) {
      bail('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) {
      bail('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) {
        bail('classEscape');
      }

      return parseUnicodeSurrogatePairEscape(res);
    }
  }

  function bail(message, details, from, to) {
    from = from == null ? pos : from;
    to = to == null ? from : to;

    var contextStart = Math.max(0, from - 10);
    var contextEnd = Math.min(to + 10, str.length);

    // Output a bit of context and a line pointing to where our error is.
    //
    // We are assuming that there are no actual newlines in the content as this is a regular expression.
    var context = '    ' + str.substring(contextStart, contextEnd);
    var pointer = '    ' + new Array(from - contextStart + 1).join(' ') + '^';

    throw SyntaxError(message + ' at position ' + from + (details ? ': ' + details : '') + '\n' + context + '\n' + pointer);
  }

  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) {
    bail('Could not parse entire input - got stuck', '', result.range[1]);
  }

  // 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 when the
  // `\2` is handled. In case the local decision turns out to be wrong after
  // the parsing has finished, the input string is parsed a second time with
  // the total number 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;
}

}());