text: (function (global, factory) {
  	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
  	typeof define === 'function' && define.amd ? define(['exports'], factory) :
  	(factory((global.acorn = global.acorn || {})));
  }(this, (function (exports) { 'use strict';
  
  // Reserved word lists for various dialects of the language
  
  var reservedWords = {
    3: "abstract boolean byte char class double enum export extends final float goto implements import int interface long native package private protected public short static super synchronized throws transient volatile",
    5: "class enum extends super const export import",
    6: "enum",
    strict: "implements interface let package private protected public static yield",
    strictBind: "eval arguments"
  };
  
  // And the keywords
  
  var ecma5AndLessKeywords = "break case catch continue debugger default do else finally for function if return switch throw try var while with null true false instanceof typeof void delete new in this";
  
  var keywords = {
    5: ecma5AndLessKeywords,
    6: ecma5AndLessKeywords + " const class extends export import super"
  };
  
  // ## Character categories
  
  // Big ugly regular expressions that match characters in the
  // whitespace, identifier, and identifier-start categories. These
  // are only applied when a character is found to actually have a
  // code point above 128.
  // Generated by `bin/generate-identifier-regex.js`.
  
  var nonASCIIidentifierStartChars = "\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\u0561-\u0587\u05d0-\u05ea\u05f0-\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\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\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-\u1877\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\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-\u312d\u3131-\u318e\u31a0-\u31ba\u31f0-\u31ff\u3400-\u4db5\u4e00-\u9fd5\ua000-\ua48c\ua4d0-\ua4fd\ua500-\ua60c\ua610-\ua61f\ua62a\ua62b\ua640-\ua66e\ua67f-\ua69d\ua6a0-\ua6ef\ua717-\ua71f\ua722-\ua788\ua78b-\ua7ae\ua7b0-\ua7b7\ua7f7-\ua801\ua803-\ua805\ua807-\ua80a\ua80c-\ua822\ua840-\ua873\ua882-\ua8b3\ua8f2-\ua8f7\ua8fb\ua8fd\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";
  var nonASCIIidentifierChars = "\u200c\u200d\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\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0859-\u085b\u08d4-\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\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\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-\u0c03\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\u0d01-\u0d03\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\u1cf8\u1cf9\u1dc0-\u1df5\u1dfb-\u1dff\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\ua900-\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";
  
  var nonASCIIidentifierStart = new RegExp("[" + nonASCIIidentifierStartChars + "]");
  var nonASCIIidentifier = new RegExp("[" + nonASCIIidentifierStartChars + nonASCIIidentifierChars + "]");
  
  nonASCIIidentifierStartChars = nonASCIIidentifierChars = null;
  
  // These are a run-length and offset encoded representation of the
  // >0xffff code points that are a valid part of identifiers. The
  // offset starts at 0x10000, and each pair of numbers represents an
  // offset to the next range, and then a size of the range. They were
  // generated by bin/generate-identifier-regex.js
  
  // eslint-disable-next-line comma-spacing
  var astralIdentifierStartCodes = [0,11,2,25,2,18,2,1,2,14,3,13,35,122,70,52,268,28,4,48,48,31,17,26,6,37,11,29,3,35,5,7,2,4,43,157,19,35,5,35,5,39,9,51,157,310,10,21,11,7,153,5,3,0,2,43,2,1,4,0,3,22,11,22,10,30,66,18,2,1,11,21,11,25,71,55,7,1,65,0,16,3,2,2,2,26,45,28,4,28,36,7,2,27,28,53,11,21,11,18,14,17,111,72,56,50,14,50,785,52,76,44,33,24,27,35,42,34,4,0,13,47,15,3,22,0,2,0,36,17,2,24,85,6,2,0,2,3,2,14,2,9,8,46,39,7,3,1,3,21,2,6,2,1,2,4,4,0,19,0,13,4,159,52,19,3,54,47,21,1,2,0,185,46,42,3,37,47,21,0,60,42,86,25,391,63,32,0,449,56,264,8,2,36,18,0,50,29,881,921,103,110,18,195,2749,1070,4050,582,8634,568,8,30,114,29,19,47,17,3,32,20,6,18,881,68,12,0,67,12,65,0,32,6124,20,754,9486,1,3071,106,6,12,4,8,8,9,5991,84,2,70,2,1,3,0,3,1,3,3,2,11,2,0,2,6,2,64,2,3,3,7,2,6,2,27,2,3,2,4,2,0,4,6,2,339,3,24,2,24,2,30,2,24,2,30,2,24,2,30,2,24,2,30,2,24,2,7,4149,196,60,67,1213,3,2,26,2,1,2,0,3,0,2,9,2,3,2,0,2,0,7,0,5,0,2,0,2,0,2,2,2,1,2,0,3,0,2,0,2,0,2,0,2,0,2,1,2,0,3,3,2,6,2,3,2,3,2,0,2,9,2,16,6,2,2,4,2,16,4421,42710,42,4148,12,221,3,5761,10591,541];
  
  // eslint-disable-next-line comma-spacing
  var astralIdentifierCodes = [509,0,227,0,150,4,294,9,1368,2,2,1,6,3,41,2,5,0,166,1,1306,2,54,14,32,9,16,3,46,10,54,9,7,2,37,13,2,9,52,0,13,2,49,13,10,2,4,9,83,11,7,0,161,11,6,9,7,3,57,0,2,6,3,1,3,2,10,0,11,1,3,6,4,4,193,17,10,9,87,19,13,9,214,6,3,8,28,1,83,16,16,9,82,12,9,9,84,14,5,9,423,9,838,7,2,7,17,9,57,21,2,13,19882,9,135,4,60,6,26,9,1016,45,17,3,19723,1,5319,4,4,5,9,7,3,6,31,3,149,2,1418,49,513,54,5,49,9,0,15,0,23,4,2,14,1361,6,2,16,3,6,2,1,2,4,2214,6,110,6,6,9,792487,239];
  
  // This has a complexity linear to the value of the code. The
  // assumption is that looking up astral identifier characters is
  // rare.
  function isInAstralSet(code, set) {
    var pos = 0x10000;
    for (var i = 0; i < set.length; i += 2) {
      pos += set[i];
      if (pos > code) { return false }
      pos += set[i + 1];
      if (pos >= code) { return true }
    }
  }
  
  // Test whether a given character code starts an identifier.
  
  function isIdentifierStart(code, astral) {
    if (code < 65) { return code === 36 }
    if (code < 91) { return true }
    if (code < 97) { return code === 95 }
    if (code < 123) { return true }
    if (code <= 0xffff) { return code >= 0xaa && nonASCIIidentifierStart.test(String.fromCharCode(code)) }
    if (astral === false) { return false }
    return isInAstralSet(code, astralIdentifierStartCodes)
  }
  
  // Test whether a given character is part of an identifier.
  
  function isIdentifierChar(code, astral) {
    if (code < 48) { return code === 36 }
    if (code < 58) { return true }
    if (code < 65) { return false }
    if (code < 91) { return true }
    if (code < 97) { return code === 95 }
    if (code < 123) { return true }
    if (code <= 0xffff) { return code >= 0xaa && nonASCIIidentifier.test(String.fromCharCode(code)) }
    if (astral === false) { return false }
    return isInAstralSet(code, astralIdentifierStartCodes) || isInAstralSet(code, astralIdentifierCodes)
  }
  
  // ## Token types
  
  // The assignment of fine-grained, information-carrying type objects
  // allows the tokenizer to store the information it has about a
  // token in a way that is very cheap for the parser to look up.
  
  // All token type variables start with an underscore, to make them
  // easy to recognize.
  
  // The `beforeExpr` property is used to disambiguate between regular
  // expressions and divisions. It is set on all token types that can
  // be followed by an expression (thus, a slash after them would be a
  // regular expression).
  //
  // The `startsExpr` property is used to check if the token ends a
  // `yield` expression. It is set on all token types that either can
  // directly start an expression (like a quotation mark) or can
  // continue an expression (like the body of a string).
  //
  // `isLoop` marks a keyword as starting a loop, which is important
  // to know when parsing a label, in order to allow or disallow
  // continue jumps to that label.
  
  var TokenType = function TokenType(label, conf) {
    if ( conf === void 0 ) conf = {};
  
    this.label = label;
    this.keyword = conf.keyword;
    this.beforeExpr = !!conf.beforeExpr;
    this.startsExpr = !!conf.startsExpr;
    this.isLoop = !!conf.isLoop;
    this.isAssign = !!conf.isAssign;
    this.prefix = !!conf.prefix;
    this.postfix = !!conf.postfix;
    this.binop = conf.binop || null;
    this.updateContext = null;
  };
  
  function binop(name, prec) {
    return new TokenType(name, {beforeExpr: true, binop: prec})
  }
  var beforeExpr = {beforeExpr: true};
  var startsExpr = {startsExpr: true};
  
  // Map keyword names to token types.
  
  var keywords$1 = {};
  
  // Succinct definitions of keyword token types
  function kw(name, options) {
    if ( options === void 0 ) options = {};
  
    options.keyword = name;
    return keywords$1[name] = new TokenType(name, options)
  }
  
  var types = {
    num: new TokenType("num", startsExpr),
    regexp: new TokenType("regexp", startsExpr),
    string: new TokenType("string", startsExpr),
    name: new TokenType("name", startsExpr),
    eof: new TokenType("eof"),
  
    // Punctuation token types.
    bracketL: new TokenType("[", {beforeExpr: true, startsExpr: true}),
    bracketR: new TokenType("]"),
    braceL: new TokenType("{", {beforeExpr: true, startsExpr: true}),
    braceR: new TokenType("}"),
    parenL: new TokenType("(", {beforeExpr: true, startsExpr: true}),
    parenR: new TokenType(")"),
    comma: new TokenType(",", beforeExpr),
    semi: new TokenType(";", beforeExpr),
    colon: new TokenType(":", beforeExpr),
    dot: new TokenType("."),
    question: new TokenType("?", beforeExpr),
    arrow: new TokenType("=>", beforeExpr),
    template: new TokenType("template"),
    invalidTemplate: new TokenType("invalidTemplate"),
    ellipsis: new TokenType("...", beforeExpr),
    backQuote: new TokenType("`", startsExpr),
    dollarBraceL: new TokenType("${", {beforeExpr: true, startsExpr: true}),
  
    // Operators. These carry several kinds of properties to help the
    // parser use them properly (the presence of these properties is
    // what categorizes them as operators).
    //
    // `binop`, when present, specifies that this operator is a binary
    // operator, and will refer to its precedence.
    //
    // `prefix` and `postfix` mark the operator as a prefix or postfix
    // unary operator.
    //
    // `isAssign` marks all of `=`, `+=`, `-=` etcetera, which act as
    // binary operators with a very low precedence, that should result
    // in AssignmentExpression nodes.
  
    eq: new TokenType("=", {beforeExpr: true, isAssign: true}),
    assign: new TokenType("_=", {beforeExpr: true, isAssign: true}),
    incDec: new TokenType("++/--", {prefix: true, postfix: true, startsExpr: true}),
    prefix: new TokenType("!/~", {beforeExpr: true, prefix: true, startsExpr: true}),
    logicalOR: binop("||", 1),
    logicalAND: binop("&&", 2),
    bitwiseOR: binop("|", 3),
    bitwiseXOR: binop("^", 4),
    bitwiseAND: binop("&", 5),
    equality: binop("==/!=/===/!==", 6),
    relational: binop("</>/<=/>=", 7),
    bitShift: binop("<</>>/>>>", 8),
    plusMin: new TokenType("+/-", {beforeExpr: true, binop: 9, prefix: true, startsExpr: true}),
    modulo: binop("%", 10),
    star: binop("*", 10),
    slash: binop("/", 10),
    starstar: new TokenType("**", {beforeExpr: true}),
  
    // Keyword token types.
    _break: kw("break"),
    _case: kw("case", beforeExpr),
    _catch: kw("catch"),
    _continue: kw("continue"),
    _debugger: kw("debugger"),
    _default: kw("default", beforeExpr),
    _do: kw("do", {isLoop: true, beforeExpr: true}),
    _else: kw("else", beforeExpr),
    _finally: kw("finally"),
    _for: kw("for", {isLoop: true}),
    _function: kw("function", startsExpr),
    _if: kw("if"),
    _return: kw("return", beforeExpr),
    _switch: kw("switch"),
    _throw: kw("throw", beforeExpr),
    _try: kw("try"),
    _var: kw("var"),
    _const: kw("const"),
    _while: kw("while", {isLoop: true}),
    _with: kw("with"),
    _new: kw("new", {beforeExpr: true, startsExpr: true}),
    _this: kw("this", startsExpr),
    _super: kw("super", startsExpr),
    _class: kw("class", startsExpr),
    _extends: kw("extends", beforeExpr),
    _export: kw("export"),
    _import: kw("import"),
    _null: kw("null", startsExpr),
    _true: kw("true", startsExpr),
    _false: kw("false", startsExpr),
    _in: kw("in", {beforeExpr: true, binop: 7}),
    _instanceof: kw("instanceof", {beforeExpr: true, binop: 7}),
    _typeof: kw("typeof", {beforeExpr: true, prefix: true, startsExpr: true}),
    _void: kw("void", {beforeExpr: true, prefix: true, startsExpr: true}),
    _delete: kw("delete", {beforeExpr: true, prefix: true, startsExpr: true})
  };
  
  // Matches a whole line break (where CRLF is considered a single
  // line break). Used to count lines.
  
  var lineBreak = /\r\n?|\n|\u2028|\u2029/;
  var lineBreakG = new RegExp(lineBreak.source, "g");
  
  function isNewLine(code) {
    return code === 10 || code === 13 || code === 0x2028 || code === 0x2029
  }
  
  var nonASCIIwhitespace = /[\u1680\u180e\u2000-\u200a\u202f\u205f\u3000\ufeff]/;
  
  var skipWhiteSpace = /(?:\s|\/\/.*|\/\*[^]*?\*\/)*/g;
  
  var ref = Object.prototype;
  var hasOwnProperty = ref.hasOwnProperty;
  var toString = ref.toString;
  
  // Checks if an object has a property.
  
  function has(obj, propName) {
    return hasOwnProperty.call(obj, propName)
  }
  
  var isArray = Array.isArray || (function (obj) { return (
    toString.call(obj) === "[object Array]"
  ); });
  
  // These are used when `options.locations` is on, for the
  // `startLoc` and `endLoc` properties.
  
  var Position = function Position(line, col) {
    this.line = line;
    this.column = col;
  };
  
  Position.prototype.offset = function offset (n) {
    return new Position(this.line, this.column + n)
  };
  
  var SourceLocation = function SourceLocation(p, start, end) {
    this.start = start;
    this.end = end;
    if (p.sourceFile !== null) { this.source = p.sourceFile; }
  };
  
  // The `getLineInfo` function is mostly useful when the
  // `locations` option is off (for performance reasons) and you
  // want to find the line/column position for a given character
  // offset. `input` should be the code string that the offset refers
  // into.
  
  function getLineInfo(input, offset) {
    for (var line = 1, cur = 0;;) {
      lineBreakG.lastIndex = cur;
      var match = lineBreakG.exec(input);
      if (match && match.index < offset) {
        ++line;
        cur = match.index + match[0].length;
      } else {
        return new Position(line, offset - cur)
      }
    }
  }
  
  // A second optional argument can be given to further configure
  // the parser process. These options are recognized:
  
  var defaultOptions = {
    // `ecmaVersion` indicates the ECMAScript version to parse. Must
    // be either 3, 5, 6 (2015), 7 (2016), or 8 (2017). This influences support
    // for strict mode, the set of reserved words, and support for
    // new syntax features. The default is 7.
    ecmaVersion: 7,
    // `sourceType` indicates the mode the code should be parsed in.
    // Can be either `"script"` or `"module"`. This influences global
    // strict mode and parsing of `import` and `export` declarations.
    sourceType: "script",
    // `onInsertedSemicolon` can be a callback that will be called
    // when a semicolon is automatically inserted. It will be passed
    // th position of the comma as an offset, and if `locations` is
    // enabled, it is given the location as a `{line, column}` object
    // as second argument.
    onInsertedSemicolon: null,
    // `onTrailingComma` is similar to `onInsertedSemicolon`, but for
    // trailing commas.
    onTrailingComma: null,
    // By default, reserved words are only enforced if ecmaVersion >= 5.
    // Set `allowReserved` to a boolean value to explicitly turn this on
    // an off. When this option has the value "never", reserved words
    // and keywords can also not be used as property names.
    allowReserved: null,
    // When enabled, a return at the top level is not considered an
    // error.
    allowReturnOutsideFunction: false,
    // When enabled, import/export statements are not constrained to
    // appearing at the top of the program.
    allowImportExportEverywhere: false,
    // When enabled, hashbang directive in the beginning of file
    // is allowed and treated as a line comment.
    allowHashBang: false,
    // When `locations` is on, `loc` properties holding objects with
    // `start` and `end` properties in `{line, column}` form (with
    // line being 1-based and column 0-based) will be attached to the
    // nodes.
    locations: false,
    // A function can be passed as `onToken` option, which will
    // cause Acorn to call that function with object in the same
    // format as tokens returned from `tokenizer().getToken()`. Note
    // that you are not allowed to call the parser from the
    // callback—that will corrupt its internal state.
    onToken: null,
    // A function can be passed as `onComment` option, which will
    // cause Acorn to call that function with `(block, text, start,
    // end)` parameters whenever a comment is skipped. `block` is a
    // boolean indicating whether this is a block (`/* */`) comment,
    // `text` is the content of the comment, and `start` and `end` are
    // character offsets that denote the start and end of the comment.
    // When the `locations` option is on, two more parameters are
    // passed, the full `{line, column}` locations of the start and
    // end of the comments. Note that you are not allowed to call the
    // parser from the callback—that will corrupt its internal state.
    onComment: null,
    // Nodes have their start and end characters offsets recorded in
    // `start` and `end` properties (directly on the node, rather than
    // the `loc` object, which holds line/column data. To also add a
    // [semi-standardized][range] `range` property holding a `[start,
    // end]` array with the same numbers, set the `ranges` option to
    // `true`.
    //
    // [range]: https://bugzilla.mozilla.org/show_bug.cgi?id=745678
    ranges: false,
    // It is possible to parse multiple files into a single AST by
    // passing the tree produced by parsing the first file as
    // `program` option in subsequent parses. This will add the
    // toplevel forms of the parsed file to the `Program` (top) node
    // of an existing parse tree.
    program: null,
    // When `locations` is on, you can pass this to record the source
    // file in every node's `loc` object.
    sourceFile: null,
    // This value, if given, is stored in every node, whether
    // `locations` is on or off.
    directSourceFile: null,
    // When enabled, parenthesized expressions are represented by
    // (non-standard) ParenthesizedExpression nodes
    preserveParens: false,
    plugins: {}
  };
  
  // Interpret and default an options object
  
  function getOptions(opts) {
    var options = {};
  
    for (var opt in defaultOptions)
      { options[opt] = opts && has(opts, opt) ? opts[opt] : defaultOptions[opt]; }
  
    if (options.ecmaVersion >= 2015)
      { options.ecmaVersion -= 2009; }
  
    if (options.allowReserved == null)
      { options.allowReserved = options.ecmaVersion < 5; }
  
    if (isArray(options.onToken)) {
      var tokens = options.onToken;
      options.onToken = function (token) { return tokens.push(token); };
    }
    if (isArray(options.onComment))
      { options.onComment = pushComment(options, options.onComment); }
  
    return options
  }
  
  function pushComment(options, array) {
    return function(block, text, start, end, startLoc, endLoc) {
      var comment = {
        type: block ? "Block" : "Line",
        value: text,
        start: start,
        end: end
      };
      if (options.locations)
        { comment.loc = new SourceLocation(this, startLoc, endLoc); }
      if (options.ranges)
        { comment.range = [start, end]; }
      array.push(comment);
    }
  }
  
  // Registered plugins
  var plugins = {};
  
  function keywordRegexp(words) {
    return new RegExp("^(?:" + words.replace(/ /g, "|") + ")$")
  }
  
  var Parser = function Parser(options, input, startPos) {
    this.options = options = getOptions(options);
    this.sourceFile = options.sourceFile;
    this.keywords = keywordRegexp(keywords[options.ecmaVersion >= 6 ? 6 : 5]);
    var reserved = "";
    if (!options.allowReserved) {
      for (var v = options.ecmaVersion;; v--)
        { if (reserved = reservedWords[v]) { break } }
      if (options.sourceType == "module") { reserved += " await"; }
    }
    this.reservedWords = keywordRegexp(reserved);
    var reservedStrict = (reserved ? reserved + " " : "") + reservedWords.strict;
    this.reservedWordsStrict = keywordRegexp(reservedStrict);
    this.reservedWordsStrictBind = keywordRegexp(reservedStrict + " " + reservedWords.strictBind);
    this.input = String(input);
  
    // Used to signal to callers of `readWord1` whether the word
    // contained any escape sequences. This is needed because words with
    // escape sequences must not be interpreted as keywords.
    this.containsEsc = false;
  
    // Load plugins
    this.loadPlugins(options.plugins);
  
    // Set up token state
  
    // The current position of the tokenizer in the input.
    if (startPos) {
      this.pos = startPos;
      this.lineStart = this.input.lastIndexOf("\n", startPos - 1) + 1;
      this.curLine = this.input.slice(0, this.lineStart).split(lineBreak).length;
    } else {
      this.pos = this.lineStart = 0;
      this.curLine = 1;
    }
  
    // Properties of the current token:
    // Its type
    this.type = types.eof;
    // For tokens that include more information than their type, the value
    this.value = null;
    // Its start and end offset
    this.start = this.end = this.pos;
    // And, if locations are used, the {line, column} object
    // corresponding to those offsets
    this.startLoc = this.endLoc = this.curPosition();
  
    // Position information for the previous token
    this.lastTokEndLoc = this.lastTokStartLoc = null;
    this.lastTokStart = this.lastTokEnd = this.pos;
  
    // The context stack is used to superficially track syntactic
    // context to predict whether a regular expression is allowed in a
    // given position.
    this.context = this.initialContext();
    this.exprAllowed = true;
  
    // Figure out if it's a module code.
    this.inModule = options.sourceType === "module";
    this.strict = this.inModule || this.strictDirective(this.pos);
  
    // Used to signify the start of a potential arrow function
    this.potentialArrowAt = -1;
  
    // Flags to track whether we are in a function, a generator, an async function.
    this.inFunction = this.inGenerator = this.inAsync = false;
    // Positions to delayed-check that yield/await does not exist in default parameters.
    this.yieldPos = this.awaitPos = 0;
    // Labels in scope.
    this.labels = [];
  
    // If enabled, skip leading hashbang line.
    if (this.pos === 0 && options.allowHashBang && this.input.slice(0, 2) === "#!")
      { this.skipLineComment(2); }
  
    // Scope tracking for duplicate variable names (see scope.js)
    this.scopeStack = [];
    this.enterFunctionScope();
  };
  
  // DEPRECATED Kept for backwards compatibility until 3.0 in case a plugin uses them
  Parser.prototype.isKeyword = function isKeyword (word) { return this.keywords.test(word) };
  Parser.prototype.isReservedWord = function isReservedWord (word) { return this.reservedWords.test(word) };
  
  Parser.prototype.extend = function extend (name, f) {
    this[name] = f(this[name]);
  };
  
  Parser.prototype.loadPlugins = function loadPlugins (pluginConfigs) {
      var this$1 = this;
  
    for (var name in pluginConfigs) {
      var plugin = plugins[name];
      if (!plugin) { throw new Error("Plugin '" + name + "' not found") }
      plugin(this$1, pluginConfigs[name]);
    }
  };
  
  Parser.prototype.parse = function parse () {
    var node = this.options.program || this.startNode();
    this.nextToken();
    return this.parseTopLevel(node)
  };
  
  var pp = Parser.prototype;
  
  // ## Parser utilities
  
  var literal = /^(?:'((?:\\.|[^'])*?)'|"((?:\\.|[^"])*?)"|;)/;
  pp.strictDirective = function(start) {
    var this$1 = this;
  
    for (;;) {
      skipWhiteSpace.lastIndex = start;
      start += skipWhiteSpace.exec(this$1.input)[0].length;
      var match = literal.exec(this$1.input.slice(start));
      if (!match) { return false }
      if ((match[1] || match[2]) == "use strict") { return true }
      start += match[0].length;
    }
  };
  
  // Predicate that tests whether the next token is of the given
  // type, and if yes, consumes it as a side effect.
  
  pp.eat = function(type) {
    if (this.type === type) {
      this.next();
      return true
    } else {
      return false
    }
  };
  
  // Tests whether parsed token is a contextual keyword.
  
  pp.isContextual = function(name) {
    return this.type === types.name && this.value === name
  };
  
  // Consumes contextual keyword if possible.
  
  pp.eatContextual = function(name) {
    return this.value === name && this.eat(types.name)
  };
  
  // Asserts that following token is given contextual keyword.
  
  pp.expectContextual = function(name) {
    if (!this.eatContextual(name)) { this.unexpected(); }
  };
  
  // Test whether a semicolon can be inserted at the current position.
  
  pp.canInsertSemicolon = function() {
    return this.type === types.eof ||
      this.type === types.braceR ||
      lineBreak.test(this.input.slice(this.lastTokEnd, this.start))
  };
  
  pp.insertSemicolon = function() {
    if (this.canInsertSemicolon()) {
      if (this.options.onInsertedSemicolon)
        { this.options.onInsertedSemicolon(this.lastTokEnd, this.lastTokEndLoc); }
      return true
    }
  };
  
  // Consume a semicolon, or, failing that, see if we are allowed to
  // pretend that there is a semicolon at this position.
  
  pp.semicolon = function() {
    if (!this.eat(types.semi) && !this.insertSemicolon()) { this.unexpected(); }
  };
  
  pp.afterTrailingComma = function(tokType, notNext) {
    if (this.type == tokType) {
      if (this.options.onTrailingComma)
        { this.options.onTrailingComma(this.lastTokStart, this.lastTokStartLoc); }
      if (!notNext)
        { this.next(); }
      return true
    }
  };
  
  // Expect a token of a given type. If found, consume it, otherwise,
  // raise an unexpected token error.
  
  pp.expect = function(type) {
    this.eat(type) || this.unexpected();
  };
  
  // Raise an unexpected token error.
  
  pp.unexpected = function(pos) {
    this.raise(pos != null ? pos : this.start, "Unexpected token");
  };
  
  function DestructuringErrors() {
    this.shorthandAssign =
    this.trailingComma =
    this.parenthesizedAssign =
    this.parenthesizedBind =
      -1;
  }
  
  pp.checkPatternErrors = function(refDestructuringErrors, isAssign) {
    if (!refDestructuringErrors) { return }
    if (refDestructuringErrors.trailingComma > -1)
      { this.raiseRecoverable(refDestructuringErrors.trailingComma, "Comma is not permitted after the rest element"); }
    var parens = isAssign ? refDestructuringErrors.parenthesizedAssign : refDestructuringErrors.parenthesizedBind;
    if (parens > -1) { this.raiseRecoverable(parens, "Parenthesized pattern"); }
  };
  
  pp.checkExpressionErrors = function(refDestructuringErrors, andThrow) {
    var pos = refDestructuringErrors ? refDestructuringErrors.shorthandAssign : -1;
    if (!andThrow) { return pos >= 0 }
    if (pos > -1) { this.raise(pos, "Shorthand property assignments are valid only in destructuring patterns"); }
  };
  
  pp.checkYieldAwaitInDefaultParams = function() {
    if (this.yieldPos && (!this.awaitPos || this.yieldPos < this.awaitPos))
      { this.raise(this.yieldPos, "Yield expression cannot be a default value"); }
    if (this.awaitPos)
      { this.raise(this.awaitPos, "Await expression cannot be a default value"); }
  };
  
  pp.isSimpleAssignTarget = function(expr) {
    if (expr.type === "ParenthesizedExpression")
      { return this.isSimpleAssignTarget(expr.expression) }
    return expr.type === "Identifier" || expr.type === "MemberExpression"
  };
  
  var pp$1 = Parser.prototype;
  
  // ### Statement parsing
  
  // Parse a program. Initializes the parser, reads any number of
  // statements, and wraps them in a Program node.  Optionally takes a
  // `program` argument.  If present, the statements will be appended
  // to its body instead of creating a new node.
  
  pp$1.parseTopLevel = function(node) {
    var this$1 = this;
  
    var exports = {};
    if (!node.body) { node.body = []; }
    while (this.type !== types.eof) {
      var stmt = this$1.parseStatement(true, true, exports);
      node.body.push(stmt);
    }
    this.adaptDirectivePrologue(node.body);
    this.next();
    if (this.options.ecmaVersion >= 6) {
      node.sourceType = this.options.sourceType;
    }
    return this.finishNode(node, "Program")
  };
  
  var loopLabel = {kind: "loop"};
  var switchLabel = {kind: "switch"};
  
  pp$1.isLet = function() {
    if (this.type !== types.name || this.options.ecmaVersion < 6 || this.value != "let") { return false }
    skipWhiteSpace.lastIndex = this.pos;
    var skip = skipWhiteSpace.exec(this.input);
    var next = this.pos + skip[0].length, nextCh = this.input.charCodeAt(next);
    if (nextCh === 91 || nextCh == 123) { return true } // '{' and '['
    if (isIdentifierStart(nextCh, true)) {
      var pos = next + 1;
      while (isIdentifierChar(this.input.charCodeAt(pos), true)) { ++pos; }
      var ident = this.input.slice(next, pos);
      if (!this.isKeyword(ident)) { return true }
    }
    return false
  };
  
  // check 'async [no LineTerminator here] function'
  // - 'async /*foo*/ function' is OK.
  // - 'async /*\n*/ function' is invalid.
  pp$1.isAsyncFunction = function() {
    if (this.type !== types.name || this.options.ecmaVersion < 8 || this.value != "async")
      { return false }
  
    skipWhiteSpace.lastIndex = this.pos;
    var skip = skipWhiteSpace.exec(this.input);
    var next = this.pos + skip[0].length;
    return !lineBreak.test(this.input.slice(this.pos, next)) &&
      this.input.slice(next, next + 8) === "function" &&
      (next + 8 == this.input.length || !isIdentifierChar(this.input.charAt(next + 8)))
  };
  
  // Parse a single statement.
  //
  // If expecting a statement and finding a slash operator, parse a
  // regular expression literal. This is to handle cases like
  // `if (foo) /blah/.exec(foo)`, where looking at the previous token
  // does not help.
  
  pp$1.parseStatement = function(declaration, topLevel, exports) {
    var starttype = this.type, node = this.startNode(), kind;
  
    if (this.isLet()) {
      starttype = types._var;
      kind = "let";
    }
  
    // Most types of statements are recognized by the keyword they
    // start with. Many are trivial to parse, some require a bit of
    // complexity.
  
    switch (starttype) {
    case types._break: case types._continue: return this.parseBreakContinueStatement(node, starttype.keyword)
    case types._debugger: return this.parseDebuggerStatement(node)
    case types._do: return this.parseDoStatement(node)
    case types._for: return this.parseForStatement(node)
    case types._function:
      if (!declaration && this.options.ecmaVersion >= 6) { this.unexpected(); }
      return this.parseFunctionStatement(node, false)
    case types._class:
      if (!declaration) { this.unexpected(); }
      return this.parseClass(node, true)
    case types._if: return this.parseIfStatement(node)
    case types._return: return this.parseReturnStatement(node)
    case types._switch: return this.parseSwitchStatement(node)
    case types._throw: return this.parseThrowStatement(node)
    case types._try: return this.parseTryStatement(node)
    case types._const: case types._var:
      kind = kind || this.value;
      if (!declaration && kind != "var") { this.unexpected(); }
      return this.parseVarStatement(node, kind)
    case types._while: return this.parseWhileStatement(node)
    case types._with: return this.parseWithStatement(node)
    case types.braceL: return this.parseBlock()
    case types.semi: return this.parseEmptyStatement(node)
    case types._export:
    case types._import:
      if (!this.options.allowImportExportEverywhere) {
        if (!topLevel)
          { this.raise(this.start, "'import' and 'export' may only appear at the top level"); }
        if (!this.inModule)
          { this.raise(this.start, "'import' and 'export' may appear only with 'sourceType: module'"); }
      }
      return starttype === types._import ? this.parseImport(node) : this.parseExport(node, exports)
  
      // If the statement does not start with a statement keyword or a
      // brace, it's an ExpressionStatement or LabeledStatement. We
      // simply start parsing an expression, and afterwards, if the
      // next token is a colon and the expression was a simple
      // Identifier node, we switch to interpreting it as a label.
    default:
      if (this.isAsyncFunction() && declaration) {
        this.next();
        return this.parseFunctionStatement(node, true)
      }
  
      var maybeName = this.value, expr = this.parseExpression();
      if (starttype === types.name && expr.type === "Identifier" && this.eat(types.colon))
        { return this.parseLabeledStatement(node, maybeName, expr) }
      else { return this.parseExpressionStatement(node, expr) }
    }
  };
  
  pp$1.parseBreakContinueStatement = function(node, keyword) {
    var this$1 = this;
  
    var isBreak = keyword == "break";
    this.next();
    if (this.eat(types.semi) || this.insertSemicolon()) { node.label = null; }
    else if (this.type !== types.name) { this.unexpected(); }
    else {
      node.label = this.parseIdent();
      this.semicolon();
    }
  
    // Verify that there is an actual destination to break or
    // continue to.
    var i = 0;
    for (; i < this.labels.length; ++i) {
      var lab = this$1.labels[i];
      if (node.label == null || lab.name === node.label.name) {
        if (lab.kind != null && (isBreak || lab.kind === "loop")) { break }
        if (node.label && isBreak) { break }
      }
    }
    if (i === this.labels.length) { this.raise(node.start, "Unsyntactic " + keyword); }
    return this.finishNode(node, isBreak ? "BreakStatement" : "ContinueStatement")
  };
  
  pp$1.parseDebuggerStatement = function(node) {
    this.next();
    this.semicolon();
    return this.finishNode(node, "DebuggerStatement")
  };
  
  pp$1.parseDoStatement = function(node) {
    this.next();
    this.labels.push(loopLabel);
    node.body = this.parseStatement(false);
    this.labels.pop();
    this.expect(types._while);
    node.test = this.parseParenExpression();
    if (this.options.ecmaVersion >= 6)
      { this.eat(types.semi); }
    else
      { this.semicolon(); }
    return this.finishNode(node, "DoWhileStatement")
  };
  
  // Disambiguating between a `for` and a `for`/`in` or `for`/`of`
  // loop is non-trivial. Basically, we have to parse the init `var`
  // statement or expression, disallowing the `in` operator (see
  // the second parameter to `parseExpression`), and then check
  // whether the next token is `in` or `of`. When there is no init
  // part (semicolon immediately after the opening parenthesis), it
  // is a regular `for` loop.
  
  pp$1.parseForStatement = function(node) {
    this.next();
    this.labels.push(loopLabel);
    this.enterLexicalScope();
    this.expect(types.parenL);
    if (this.type === types.semi) { return this.parseFor(node, null) }
    var isLet = this.isLet();
    if (this.type === types._var || this.type === types._const || isLet) {
      var init$1 = this.startNode(), kind = isLet ? "let" : this.value;
      this.next();
      this.parseVar(init$1, true, kind);
      this.finishNode(init$1, "VariableDeclaration");
      if ((this.type === types._in || (this.options.ecmaVersion >= 6 && this.isContextual("of"))) && init$1.declarations.length === 1 &&
          !(kind !== "var" && init$1.declarations[0].init))
        { return this.parseForIn(node, init$1) }
      return this.parseFor(node, init$1)
    }
    var refDestructuringErrors = new DestructuringErrors;
    var init = this.parseExpression(true, refDestructuringErrors);
    if (this.type === types._in || (this.options.ecmaVersion >= 6 && this.isContextual("of"))) {
      this.toAssignable(init);
      this.checkLVal(init);
      this.checkPatternErrors(refDestructuringErrors, true);
      return this.parseForIn(node, init)
    } else {
      this.checkExpressionErrors(refDestructuringErrors, true);
    }
    return this.parseFor(node, init)
  };
  
  pp$1.parseFunctionStatement = function(node, isAsync) {
    this.next();
    return this.parseFunction(node, true, false, isAsync)
  };
  
  pp$1.isFunction = function() {
    return this.type === types._function || this.isAsyncFunction()
  };
  
  pp$1.parseIfStatement = function(node) {
    this.next();
    node.test = this.parseParenExpression();
    // allow function declarations in branches, but only in non-strict mode
    node.consequent = this.parseStatement(!this.strict && this.isFunction());
    node.alternate = this.eat(types._else) ? this.parseStatement(!this.strict && this.isFunction()) : null;
    return this.finishNode(node, "IfStatement")
  };
  
  pp$1.parseReturnStatement = function(node) {
    if (!this.inFunction && !this.options.allowReturnOutsideFunction)
      { this.raise(this.start, "'return' outside of function"); }
    this.next();
  
    // In `return` (and `break`/`continue`), the keywords with
    // optional arguments, we eagerly look for a semicolon or the
    // possibility to insert one.
  
    if (this.eat(types.semi) || this.insertSemicolon()) { node.argument = null; }
    else { node.argument = this.parseExpression(); this.semicolon(); }
    return this.finishNode(node, "ReturnStatement")
  };
  
  pp$1.parseSwitchStatement = function(node) {
    var this$1 = this;
  
    this.next();
    node.discriminant = this.parseParenExpression();
    node.cases = [];
    this.expect(types.braceL);
    this.labels.push(switchLabel);
    this.enterLexicalScope();
  
    // Statements under must be grouped (by label) in SwitchCase
    // nodes. `cur` is used to keep the node that we are currently
    // adding statements to.
  
    var cur;
    for (var sawDefault = false; this.type != types.braceR;) {
      if (this$1.type === types._case || this$1.type === types._default) {
        var isCase = this$1.type === types._case;
        if (cur) { this$1.finishNode(cur, "SwitchCase"); }
        node.cases.push(cur = this$1.startNode());
        cur.consequent = [];
        this$1.next();
        if (isCase) {
          cur.test = this$1.parseExpression();
        } else {
          if (sawDefault) { this$1.raiseRecoverable(this$1.lastTokStart, "Multiple default clauses"); }
          sawDefault = true;
          cur.test = null;
        }
        this$1.expect(types.colon);
      } else {
        if (!cur) { this$1.unexpected(); }
        cur.consequent.push(this$1.parseStatement(true));
      }
    }
    this.exitLexicalScope();
    if (cur) { this.finishNode(cur, "SwitchCase"); }
    this.next(); // Closing brace
    this.labels.pop();
    return this.finishNode(node, "SwitchStatement")
  };
  
  pp$1.parseThrowStatement = function(node) {
    this.next();
    if (lineBreak.test(this.input.slice(this.lastTokEnd, this.start)))
      { this.raise(this.lastTokEnd, "Illegal newline after throw"); }
    node.argument = this.parseExpression();
    this.semicolon();
    return this.finishNode(node, "ThrowStatement")
  };
  
  // Reused empty array added for node fields that are always empty.
  
  var empty = [];
  
  pp$1.parseTryStatement = function(node) {
    this.next();
    node.block = this.parseBlock();
    node.handler = null;
    if (this.type === types._catch) {
      var clause = this.startNode();
      this.next();
      this.expect(types.parenL);
      clause.param = this.parseBindingAtom();
      this.enterLexicalScope();
      this.checkLVal(clause.param, "let");
      this.expect(types.parenR);
      clause.body = this.parseBlock(false);
      this.exitLexicalScope();
      node.handler = this.finishNode(clause, "CatchClause");
    }
    node.finalizer = this.eat(types._finally) ? this.parseBlock() : null;
    if (!node.handler && !node.finalizer)
      { this.raise(node.start, "Missing catch or finally clause"); }
    return this.finishNode(node, "TryStatement")
  };
  
  pp$1.parseVarStatement = function(node, kind) {
    this.next();
    this.parseVar(node, false, kind);
    this.semicolon();
    return this.finishNode(node, "VariableDeclaration")
  };
  
  pp$1.parseWhileStatement = function(node) {
    this.next();
    node.test = this.parseParenExpression();
    this.labels.push(loopLabel);
    node.body = this.parseStatement(false);
    this.labels.pop();
    return this.finishNode(node, "WhileStatement")
  };
  
  pp$1.parseWithStatement = function(node) {
    if (this.strict) { this.raise(this.start, "'with' in strict mode"); }
    this.next();
    node.object = this.parseParenExpression();
    node.body = this.parseStatement(false);
    return this.finishNode(node, "WithStatement")
  };
  
  pp$1.parseEmptyStatement = function(node) {
    this.next();
    return this.finishNode(node, "EmptyStatement")
  };
  
  pp$1.parseLabeledStatement = function(node, maybeName, expr) {
    var this$1 = this;
  
    for (var i$1 = 0, list = this$1.labels; i$1 < list.length; i$1 += 1)
      {
      var label = list[i$1];
  
      if (label.name === maybeName)
        { this$1.raise(expr.start, "Label '" + maybeName + "' is already declared");
    } }
    var kind = this.type.isLoop ? "loop" : this.type === types._switch ? "switch" : null;
    for (var i = this.labels.length - 1; i >= 0; i--) {
      var label$1 = this$1.labels[i];
      if (label$1.statementStart == node.start) {
        label$1.statementStart = this$1.start;
        label$1.kind = kind;
      } else { break }
    }
    this.labels.push({name: maybeName, kind: kind, statementStart: this.start});
    node.body = this.parseStatement(true);
    if (node.body.type == "ClassDeclaration" ||
        node.body.type == "VariableDeclaration" && node.body.kind != "var" ||
        node.body.type == "FunctionDeclaration" && (this.strict || node.body.generator))
      { this.raiseRecoverable(node.body.start, "Invalid labeled declaration"); }
    this.labels.pop();
    node.label = expr;
    return this.finishNode(node, "LabeledStatement")
  };
  
  pp$1.parseExpressionStatement = function(node, expr) {
    node.expression = expr;
    this.semicolon();
    return this.finishNode(node, "ExpressionStatement")
  };
  
  // Parse a semicolon-enclosed block of statements, handling `"use
  // strict"` declarations when `allowStrict` is true (used for
  // function bodies).
  
  pp$1.parseBlock = function(createNewLexicalScope) {
    var this$1 = this;
    if ( createNewLexicalScope === void 0 ) createNewLexicalScope = true;
  
    var node = this.startNode();
    node.body = [];
    this.expect(types.braceL);
    if (createNewLexicalScope) {
      this.enterLexicalScope();
    }
    while (!this.eat(types.braceR)) {
      var stmt = this$1.parseStatement(true);
      node.body.push(stmt);
    }
    if (createNewLexicalScope) {
      this.exitLexicalScope();
    }
    return this.finishNode(node, "BlockStatement")
  };
  
  // Parse a regular `for` loop. The disambiguation code in
  // `parseStatement` will already have parsed the init statement or
  // expression.
  
  pp$1.parseFor = function(node, init) {
    node.init = init;
    this.expect(types.semi);
    node.test = this.type === types.semi ? null : this.parseExpression();
    this.expect(types.semi);
    node.update = this.type === types.parenR ? null : this.parseExpression();
    this.expect(types.parenR);
    this.exitLexicalScope();
    node.body = this.parseStatement(false);
    this.labels.pop();
    return this.finishNode(node, "ForStatement")
  };
  
  // Parse a `for`/`in` and `for`/`of` loop, which are almost
  // same from parser's perspective.
  
  pp$1.parseForIn = function(node, init) {
    var type = this.type === types._in ? "ForInStatement" : "ForOfStatement";
    this.next();
    node.left = init;
    node.right = this.parseExpression();
    this.expect(types.parenR);
    this.exitLexicalScope();
    node.body = this.parseStatement(false);
    this.labels.pop();
    return this.finishNode(node, type)
  };
  
  // Parse a list of variable declarations.
  
  pp$1.parseVar = function(node, isFor, kind) {
    var this$1 = this;
  
    node.declarations = [];
    node.kind = kind;
    for (;;) {
      var decl = this$1.startNode();
      this$1.parseVarId(decl, kind);
      if (this$1.eat(types.eq)) {
        decl.init = this$1.parseMaybeAssign(isFor);
      } else if (kind === "const" && !(this$1.type === types._in || (this$1.options.ecmaVersion >= 6 && this$1.isContextual("of")))) {
        this$1.unexpected();
      } else if (decl.id.type != "Identifier" && !(isFor && (this$1.type === types._in || this$1.isContextual("of")))) {
        this$1.raise(this$1.lastTokEnd, "Complex binding patterns require an initialization value");
      } else {
        decl.init = null;
      }
      node.declarations.push(this$1.finishNode(decl, "VariableDeclarator"));
      if (!this$1.eat(types.comma)) { break }
    }
    return node
  };
  
  pp$1.parseVarId = function(decl, kind) {
    decl.id = this.parseBindingAtom(kind);
    this.checkLVal(decl.id, kind, false);
  };
  
  // Parse a function declaration or literal (depending on the
  // `isStatement` parameter).
  
  pp$1.parseFunction = function(node, isStatement, allowExpressionBody, isAsync) {
    this.initFunction(node);
    if (this.options.ecmaVersion >= 6 && !isAsync)
      { node.generator = this.eat(types.star); }
    if (this.options.ecmaVersion >= 8)
      { node.async = !!isAsync; }
  
    if (isStatement) {
      node.id = isStatement === "nullableID" && this.type != types.name ? null : this.parseIdent();
      if (node.id) {
        this.checkLVal(node.id, "var");
      }
    }
  
    var oldInGen = this.inGenerator, oldInAsync = this.inAsync,
        oldYieldPos = this.yieldPos, oldAwaitPos = this.awaitPos, oldInFunc = this.inFunction;
    this.inGenerator = node.generator;
    this.inAsync = node.async;
    this.yieldPos = 0;
    this.awaitPos = 0;
    this.inFunction = true;
    this.enterFunctionScope();
  
    if (!isStatement)
      { node.id = this.type == types.name ? this.parseIdent() : null; }
  
    this.parseFunctionParams(node);
    this.parseFunctionBody(node, allowExpressionBody);
  
    this.inGenerator = oldInGen;
    this.inAsync = oldInAsync;
    this.yieldPos = oldYieldPos;
    this.awaitPos = oldAwaitPos;
    this.inFunction = oldInFunc;
    return this.finishNode(node, isStatement ? "FunctionDeclaration" : "FunctionExpression")
  };
  
  pp$1.parseFunctionParams = function(node) {
    this.expect(types.parenL);
    node.params = this.parseBindingList(types.parenR, false, this.options.ecmaVersion >= 8);
    this.checkYieldAwaitInDefaultParams();
  };
  
  // Parse a class declaration or literal (depending on the
  // `isStatement` parameter).
  
  pp$1.parseClass = function(node, isStatement) {
    var this$1 = this;
  
    this.next();
  
    this.parseClassId(node, isStatement);
    this.parseClassSuper(node);
    var classBody = this.startNode();
    var hadConstructor = false;
    classBody.body = [];
    this.expect(types.braceL);
    while (!this.eat(types.braceR)) {
      if (this$1.eat(types.semi)) { continue }
      var method = this$1.startNode();
      var isGenerator = this$1.eat(types.star);
      var isAsync = false;
      var isMaybeStatic = this$1.type === types.name && this$1.value === "static";
      this$1.parsePropertyName(method);
      method.static = isMaybeStatic && this$1.type !== types.parenL;
      if (method.static) {
        if (isGenerator) { this$1.unexpected(); }
        isGenerator = this$1.eat(types.star);
        this$1.parsePropertyName(method);
      }
      if (this$1.options.ecmaVersion >= 8 && !isGenerator && !method.computed &&
          method.key.type === "Identifier" && method.key.name === "async" && this$1.type !== types.parenL &&
          !this$1.canInsertSemicolon()) {
        isAsync = true;
        this$1.parsePropertyName(method);
      }
      method.kind = "method";
      var isGetSet = false;
      if (!method.computed) {
        var key = method.key;
        if (!isGenerator && !isAsync && key.type === "Identifier" && this$1.type !== types.parenL && (key.name === "get" || key.name === "set")) {
          isGetSet = true;
          method.kind = key.name;
          key = this$1.parsePropertyName(method);
        }
        if (!method.static && (key.type === "Identifier" && key.name === "constructor" ||
            key.type === "Literal" && key.value === "constructor")) {
          if (hadConstructor) { this$1.raise(key.start, "Duplicate constructor in the same class"); }
          if (isGetSet) { this$1.raise(key.start, "Constructor can't have get/set modifier"); }
          if (isGenerator) { this$1.raise(key.start, "Constructor can't be a generator"); }
          if (isAsync) { this$1.raise(key.start, "Constructor can't be an async method"); }
          method.kind = "constructor";
          hadConstructor = true;
        }
      }
      this$1.parseClassMethod(classBody, method, isGenerator, isAsync);
      if (isGetSet) {
        var paramCount = method.kind === "get" ? 0 : 1;
        if (method.value.params.length !== paramCount) {
          var start = method.value.start;
          if (method.kind === "get")
            { this$1.raiseRecoverable(start, "getter should have no params"); }
          else
            { this$1.raiseRecoverable(start, "setter should have exactly one param"); }
        } else {
          if (method.kind === "set" && method.value.params[0].type === "RestElement")
            { this$1.raiseRecoverable(method.value.params[0].start, "Setter cannot use rest params"); }
        }
      }
    }
    node.body = this.finishNode(classBody, "ClassBody");
    return this.finishNode(node, isStatement ? "ClassDeclaration" : "ClassExpression")
  };
  
  pp$1.parseClassMethod = function(classBody, method, isGenerator, isAsync) {
    method.value = this.parseMethod(isGenerator, isAsync);
    classBody.body.push(this.finishNode(method, "MethodDefinition"));
  };
  
  pp$1.parseClassId = function(node, isStatement) {
    node.id = this.type === types.name ? this.parseIdent() : isStatement === true ? this.unexpected() : null;
  };
  
  pp$1.parseClassSuper = function(node) {
    node.superClass = this.eat(types._extends) ? this.parseExprSubscripts() : null;
  };
  
  // Parses module export declaration.
  
  pp$1.parseExport = function(node, exports) {
    var this$1 = this;
  
    this.next();
    // export * from '...'
    if (this.eat(types.star)) {
      this.expectContextual("from");
      node.source = this.type === types.string ? this.parseExprAtom() : this.unexpected();
      this.semicolon();
      return this.finishNode(node, "ExportAllDeclaration")
    }
    if (this.eat(types._default)) { // export default ...
      this.checkExport(exports, "default", this.lastTokStart);
      var isAsync;
      if (this.type === types._function || (isAsync = this.isAsyncFunction())) {
        var fNode = this.startNode();
        this.next();
        if (isAsync) { this.next(); }
        node.declaration = this.parseFunction(fNode, "nullableID", false, isAsync);
      } else if (this.type === types._class) {
        var cNode = this.startNode();
        node.declaration = this.parseClass(cNode, "nullableID");
      } else {
        node.declaration = this.parseMaybeAssign();
        this.semicolon();
      }
      return this.finishNode(node, "ExportDefaultDeclaration")
    }
    // export var|const|let|function|class ...
    if (this.shouldParseExportStatement()) {
      node.declaration = this.parseStatement(true);
      if (node.declaration.type === "VariableDeclaration")
        { this.checkVariableExport(exports, node.declaration.declarations); }
      else
        { this.checkExport(exports, node.declaration.id.name, node.declaration.id.start); }
      node.specifiers = [];
      node.source = null;
    } else { // export { x, y as z } [from '...']
      node.declaration = null;
      node.specifiers = this.parseExportSpecifiers(exports);
      if (this.eatContextual("from")) {
        node.source = this.type === types.string ? this.parseExprAtom() : this.unexpected();
      } else {
        // check for keywords used as local names
        for (var i = 0, list = node.specifiers; i < list.length; i += 1) {
          var spec = list[i];
  
          this$1.checkUnreserved(spec.local);
        }
  
        node.source = null;
      }
      this.semicolon();
    }
    return this.finishNode(node, "ExportNamedDeclaration")
  };
  
  pp$1.checkExport = function(exports, name, pos) {
    if (!exports) { return }
    if (has(exports, name))
      { this.raiseRecoverable(pos, "Duplicate export '" + name + "'"); }
    exports[name] = true;
  };
  
  pp$1.checkPatternExport = function(exports, pat) {
    var this$1 = this;
  
    var type = pat.type;
    if (type == "Identifier")
      { this.checkExport(exports, pat.name, pat.start); }
    else if (type == "ObjectPattern")
      { for (var i = 0, list = pat.properties; i < list.length; i += 1)
        {
          var prop = list[i];
  
          this$1.checkPatternExport(exports, prop.value);
        } }
    else if (type == "ArrayPattern")
      { for (var i$1 = 0, list$1 = pat.elements; i$1 < list$1.length; i$1 += 1) {
        var elt = list$1[i$1];
  
          if (elt) { this$1.checkPatternExport(exports, elt); }
      } }
    else if (type == "AssignmentPattern")
      { this.checkPatternExport(exports, pat.left); }
    else if (type == "ParenthesizedExpression")
      { this.checkPatternExport(exports, pat.expression); }
  };
  
  pp$1.checkVariableExport = function(exports, decls) {
    var this$1 = this;
  
    if (!exports) { return }
    for (var i = 0, list = decls; i < list.length; i += 1)
      {
      var decl = list[i];
  
      this$1.checkPatternExport(exports, decl.id);
    }
  };
  
  pp$1.shouldParseExportStatement = function() {
    return this.type.keyword === "var" ||
      this.type.keyword === "const" ||
      this.type.keyword === "class" ||
      this.type.keyword === "function" ||
      this.isLet() ||
      this.isAsyncFunction()
  };
  
  // Parses a comma-separated list of module exports.
  
  pp$1.parseExportSpecifiers = function(exports) {
    var this$1 = this;
  
    var nodes = [], first = true;
    // export { x, y as z } [from '...']
    this.expect(types.braceL);
    while (!this.eat(types.braceR)) {
      if (!first) {
        this$1.expect(types.comma);
        if (this$1.afterTrailingComma(types.braceR)) { break }
      } else { first = false; }
  
      var node = this$1.startNode();
      node.local = this$1.parseIdent(true);
      node.exported = this$1.eatContextual("as") ? this$1.parseIdent(true) : node.local;
      this$1.checkExport(exports, node.exported.name, node.exported.start);
      nodes.push(this$1.finishNode(node, "ExportSpecifier"));
    }
    return nodes
  };
  
  // Parses import declaration.
  
  pp$1.parseImport = function(node) {
    this.next();
    // import '...'
    if (this.type === types.string) {
      node.specifiers = empty;
      node.source = this.parseExprAtom();
    } else {
      node.specifiers = this.parseImportSpecifiers();
      this.expectContextual("from");
      node.source = this.type === types.string ? this.parseExprAtom() : this.unexpected();
    }
    this.semicolon();
    return this.finishNode(node, "ImportDeclaration")
  };
  
  // Parses a comma-separated list of module imports.
  
  pp$1.parseImportSpecifiers = function() {
    var this$1 = this;
  
    var nodes = [], first = true;
    if (this.type === types.name) {
      // import defaultObj, { x, y as z } from '...'
      var node = this.startNode();
      node.local = this.parseIdent();
      this.checkLVal(node.local, "let");
      nodes.push(this.finishNode(node, "ImportDefaultSpecifier"));
      if (!this.eat(types.comma)) { return nodes }
    }
    if (this.type === types.star) {
      var node$1 = this.startNode();
      this.next();
      this.expectContextual("as");
      node$1.local = this.parseIdent();
      this.checkLVal(node$1.local, "let");
      nodes.push(this.finishNode(node$1, "ImportNamespaceSpecifier"));
      return nodes
    }
    this.expect(types.braceL);
    while (!this.eat(types.braceR)) {
      if (!first) {
        this$1.expect(types.comma);
        if (this$1.afterTrailingComma(types.braceR)) { break }
      } else { first = false; }
  
      var node$2 = this$1.startNode();
      node$2.imported = this$1.parseIdent(true);
      if (this$1.eatContextual("as")) {
        node$2.local = this$1.parseIdent();
      } else {
        this$1.checkUnreserved(node$2.imported);
        node$2.local = node$2.imported;
      }
      this$1.checkLVal(node$2.local, "let");
      nodes.push(this$1.finishNode(node$2, "ImportSpecifier"));
    }
    return nodes
  };
  
  // Set `ExpressionStatement#directive` property for directive prologues.
  pp$1.adaptDirectivePrologue = function(statements) {
    for (var i = 0; i < statements.length && this.isDirectiveCandidate(statements[i]); ++i) {
      statements[i].directive = statements[i].expression.raw.slice(1, -1);
    }
  };
  pp$1.isDirectiveCandidate = function(statement) {
    return (
      statement.type === "ExpressionStatement" &&
      statement.expression.type === "Literal" &&
      typeof statement.expression.value === "string" &&
      // Reject parenthesized strings.
      (this.input[statement.start] === "\"" || this.input[statement.start] === "'")
    )
  };
  
  var pp$2 = Parser.prototype;
  
  // Convert existing expression atom to assignable pattern
  // if possible.
  
  pp$2.toAssignable = function(node, isBinding) {
    var this$1 = this;
  
    if (this.options.ecmaVersion >= 6 && node) {
      switch (node.type) {
      case "Identifier":
        if (this.inAsync && node.name === "await")
          { this.raise(node.start, "Can not use 'await' as identifier inside an async function"); }
        break
  
      case "ObjectPattern":
      case "ArrayPattern":
        break
  
      case "ObjectExpression":
        node.type = "ObjectPattern";
        for (var i = 0, list = node.properties; i < list.length; i += 1) {
          var prop = list[i];
  
        if (prop.kind !== "init") { this$1.raise(prop.key.start, "Object pattern can't contain getter or setter"); }
          this$1.toAssignable(prop.value, isBinding);
        }
        break
  
      case "ArrayExpression":
        node.type = "ArrayPattern";
        this.toAssignableList(node.elements, isBinding);
        break
  
      case "AssignmentExpression":
        if (node.operator === "=") {
          node.type = "AssignmentPattern";
          delete node.operator;
          this.toAssignable(node.left, isBinding);
          // falls through to AssignmentPattern
        } else {
          this.raise(node.left.end, "Only '=' operator can be used for specifying default value.");
          break
        }
  
      case "AssignmentPattern":
        break
  
      case "ParenthesizedExpression":
        this.toAssignable(node.expression, isBinding);
        break
  
      case "MemberExpression":
        if (!isBinding) { break }
  
      default:
        this.raise(node.start, "Assigning to rvalue");
      }
    }
    return node
  };
  
  // Convert list of expression atoms to binding list.
  
  pp$2.toAssignableList = function(exprList, isBinding) {
    var this$1 = this;
  
    var end = exprList.length;
    if (end) {
      var last = exprList[end - 1];
      if (last && last.type == "RestElement") {
        --end;
      } else if (last && last.type == "SpreadElement") {
        last.type = "RestElement";
        var arg = last.argument;
        this.toAssignable(arg, isBinding);
        --end;
      }
  
      if (this.options.ecmaVersion === 6 && isBinding && last && last.type === "RestElement" && last.argument.type !== "Identifier")
        { this.unexpected(last.argument.start); }
    }
    for (var i = 0; i < end; i++) {
      var elt = exprList[i];
      if (elt) { this$1.toAssignable(elt, isBinding); }
    }
    return exprList
  };
  
  // Parses spread element.
  
  pp$2.parseSpread = function(refDestructuringErrors) {
    var node = this.startNode();
    this.next();
    node.argument = this.parseMaybeAssign(false, refDestructuringErrors);
    return this.finishNode(node, "SpreadElement")
  };
  
  pp$2.parseRestBinding = function() {
    var node = this.startNode();
    this.next();
  
    // RestElement inside of a function parameter must be an identifier
    if (this.options.ecmaVersion === 6 && this.type !== types.name)
      { this.unexpected(); }
  
    node.argument = this.parseBindingAtom();
  
    return this.finishNode(node, "RestElement")
  };
  
  // Parses lvalue (assignable) atom.
  
  pp$2.parseBindingAtom = function() {
    if (this.options.ecmaVersion >= 6) {
      switch (this.type) {
      case types.bracketL:
        var node = this.startNode();
        this.next();
        node.elements = this.parseBindingList(types.bracketR, true, true);
        return this.finishNode(node, "ArrayPattern")
  
      case types.braceL:
        return this.parseObj(true)
      }
    }
    return this.parseIdent()
  };
  
  pp$2.parseBindingList = function(close, allowEmpty, allowTrailingComma) {
    var this$1 = this;
  
    var elts = [], first = true;
    while (!this.eat(close)) {
      if (first) { first = false; }
      else { this$1.expect(types.comma); }
      if (allowEmpty && this$1.type === types.comma) {
        elts.push(null);
      } else if (allowTrailingComma && this$1.afterTrailingComma(close)) {
        break
      } else if (this$1.type === types.ellipsis) {
        var rest = this$1.parseRestBinding();
        this$1.parseBindingListItem(rest);
        elts.push(rest);
        if (this$1.type === types.comma) { this$1.raise(this$1.start, "Comma is not permitted after the rest element"); }
        this$1.expect(close);
        break
      } else {
        var elem = this$1.parseMaybeDefault(this$1.start, this$1.startLoc);
        this$1.parseBindingListItem(elem);
        elts.push(elem);
      }
    }
    return elts
  };
  
  pp$2.parseBindingListItem = function(param) {
    return param
  };
  
  // Parses assignment pattern around given atom if possible.
  
  pp$2.parseMaybeDefault = function(startPos, startLoc, left) {
    left = left || this.parseBindingAtom();
    if (this.options.ecmaVersion < 6 || !this.eat(types.eq)) { return left }
    var node = this.startNodeAt(startPos, startLoc);
    node.left = left;
    node.right = this.parseMaybeAssign();
    return this.finishNode(node, "AssignmentPattern")
  };
  
  // Verify that a node is an lval — something that can be assigned
  // to.
  // bindingType can be either:
  // 'var' indicating that the lval creates a 'var' binding
  // 'let' indicating that the lval creates a lexical ('let' or 'const') binding
  // 'none' indicating that the binding should be checked for illegal identifiers, but not for duplicate references
  
  pp$2.checkLVal = function(expr, bindingType, checkClashes) {
    var this$1 = this;
  
    switch (expr.type) {
    case "Identifier":
      if (this.strict && this.reservedWordsStrictBind.test(expr.name))
        { this.raiseRecoverable(expr.start, (bindingType ? "Binding " : "Assigning to ") + expr.name + " in strict mode"); }
      if (checkClashes) {
        if (has(checkClashes, expr.name))
          { this.raiseRecoverable(expr.start, "Argument name clash"); }
        checkClashes[expr.name] = true;
      }
      if (bindingType && bindingType !== "none") {
        if (
          bindingType === "var" && !this.canDeclareVarName(expr.name) ||
          bindingType !== "var" && !this.canDeclareLexicalName(expr.name)
        ) {
          this.raiseRecoverable(expr.start, ("Identifier '" + (expr.name) + "' has already been declared"));
        }
        if (bindingType === "var") {
          this.declareVarName(expr.name);
        } else {
          this.declareLexicalName(expr.name);
        }
      }
      break
  
    case "MemberExpression":
      if (bindingType) { this.raiseRecoverable(expr.start, (bindingType ? "Binding" : "Assigning to") + " member expression"); }
      break
  
    case "ObjectPattern":
      for (var i = 0, list = expr.properties; i < list.length; i += 1)
        {
      var prop = list[i];
  
      this$1.checkLVal(prop.value, bindingType, checkClashes);
    }
      break
  
    case "ArrayPattern":
      for (var i$1 = 0, list$1 = expr.elements; i$1 < list$1.length; i$1 += 1) {
        var elem = list$1[i$1];
  
      if (elem) { this$1.checkLVal(elem, bindingType, checkClashes); }
      }
      break
  
    case "AssignmentPattern":
      this.checkLVal(expr.left, bindingType, checkClashes);
      break
  
    case "RestElement":
      this.checkLVal(expr.argument, bindingType, checkClashes);
      break
  
    case "ParenthesizedExpression":
      this.checkLVal(expr.expression, bindingType, checkClashes);
      break
  
    default:
      this.raise(expr.start, (bindingType ? "Binding" : "Assigning to") + " rvalue");
    }
  };
  
  // A recursive descent parser operates by defining functions for all
  // syntactic elements, and recursively calling those, each function
  // advancing the input stream and returning an AST node. Precedence
  // of constructs (for example, the fact that `!x[1]` means `!(x[1])`
  // instead of `(!x)[1]` is handled by the fact that the parser
  // function that parses unary prefix operators is called first, and
  // in turn calls the function that parses `[]` subscripts — that
  // way, it'll receive the node for `x[1]` already parsed, and wraps
  // *that* in the unary operator node.
  //
  // Acorn uses an [operator precedence parser][opp] to handle binary
  // operator precedence, because it is much more compact than using
  // the technique outlined above, which uses different, nesting
  // functions to specify precedence, for all of the ten binary
  // precedence levels that JavaScript defines.
  //
  // [opp]: http://en.wikipedia.org/wiki/Operator-precedence_parser
  
  var pp$3 = Parser.prototype;
  
  // Check if property name clashes with already added.
  // Object/class getters and setters are not allowed to clash —
  // either with each other or with an init property — and in
  // strict mode, init properties are also not allowed to be repeated.
  
  pp$3.checkPropClash = function(prop, propHash) {
    if (this.options.ecmaVersion >= 6 && (prop.computed || prop.method || prop.shorthand))
      { return }
    var key = prop.key;
    var name;
    switch (key.type) {
    case "Identifier": name = key.name; break
    case "Literal": name = String(key.value); break
    default: return
    }
    var kind = prop.kind;
    if (this.options.ecmaVersion >= 6) {
      if (name === "__proto__" && kind === "init") {
        if (propHash.proto) { this.raiseRecoverable(key.start, "Redefinition of __proto__ property"); }
        propHash.proto = true;
      }
      return
    }
    name = "$" + name;
    var other = propHash[name];
    if (other) {
      var redefinition;
      if (kind === "init") {
        redefinition = this.strict && other.init || other.get || other.set;
      } else {
        redefinition = other.init || other[kind];
      }
      if (redefinition)
        { this.raiseRecoverable(key.start, "Redefinition of property"); }
    } else {
      other = propHash[name] = {
        init: false,
        get: false,
        set: false
      };
    }
    other[kind] = true;
  };
  
  // ### Expression parsing
  
  // These nest, from the most general expression type at the top to
  // 'atomic', nondivisible expression types at the bottom. Most of
  // the functions will simply let the function(s) below them parse,
  // and, *if* the syntactic construct they handle is present, wrap
  // the AST node that the inner parser gave them in another node.
  
  // Parse a full expression. The optional arguments are used to
  // forbid the `in` operator (in for loops initalization expressions)
  // and provide reference for storing '=' operator inside shorthand
  // property assignment in contexts where both object expression
  // and object pattern might appear (so it's possible to raise
  // delayed syntax error at correct position).
  
  pp$3.parseExpression = function(noIn, refDestructuringErrors) {
    var this$1 = this;
  
    var startPos = this.start, startLoc = this.startLoc;
    var expr = this.parseMaybeAssign(noIn, refDestructuringErrors);
    if (this.type === types.comma) {
      var node = this.startNodeAt(startPos, startLoc);
      node.expressions = [expr];
      while (this.eat(types.comma)) { node.expressions.push(this$1.parseMaybeAssign(noIn, refDestructuringErrors)); }
      return this.finishNode(node, "SequenceExpression")
    }
    return expr
  };
  
  // Parse an assignment expression. This includes applications of
  // operators like `+=`.
  
  pp$3.parseMaybeAssign = function(noIn, refDestructuringErrors, afterLeftParse) {
    if (this.inGenerator && this.isContextual("yield")) { return this.parseYield() }
  
    var ownDestructuringErrors = false, oldParenAssign = -1, oldTrailingComma = -1;
    if (refDestructuringErrors) {
      oldParenAssign = refDestructuringErrors.parenthesizedAssign;
      oldTrailingComma = refDestructuringErrors.trailingComma;
      refDestructuringErrors.parenthesizedAssign = refDestructuringErrors.trailingComma = -1;
    } else {
      refDestructuringErrors = new DestructuringErrors;
      ownDestructuringErrors = true;
    }
  
    var startPos = this.start, startLoc = this.startLoc;
    if (this.type == types.parenL || this.type == types.name)
      { this.potentialArrowAt = this.start; }
    var left = this.parseMaybeConditional(noIn, refDestructuringErrors);
    if (afterLeftParse) { left = afterLeftParse.call(this, left, startPos, startLoc); }
    if (this.type.isAssign) {
      this.checkPatternErrors(refDestructuringErrors, true);
      if (!ownDestructuringErrors) { DestructuringErrors.call(refDestructuringErrors); }
      var node = this.startNodeAt(startPos, startLoc);
      node.operator = this.value;
      node.left = this.type === types.eq ? this.toAssignable(left) : left;
      refDestructuringErrors.shorthandAssign = -1; // reset because shorthand default was used correctly
      this.checkLVal(left);
      this.next();
      node.right = this.parseMaybeAssign(noIn);
      return this.finishNode(node, "AssignmentExpression")
    } else {
      if (ownDestructuringErrors) { this.checkExpressionErrors(refDestructuringErrors, true); }
    }
    if (oldParenAssign > -1) { refDestructuringErrors.parenthesizedAssign = oldParenAssign; }
    if (oldTrailingComma > -1) { refDestructuringErrors.trailingComma = oldTrailingComma; }
    return left
  };
  
  // Parse a ternary conditional (`?:`) operator.
  
  pp$3.parseMaybeConditional = function(noIn, refDestructuringErrors) {
    var startPos = this.start, startLoc = this.startLoc;
    var expr = this.parseExprOps(noIn, refDestructuringErrors);
    if (this.checkExpressionErrors(refDestructuringErrors)) { return expr }
    if (this.eat(types.question)) {
      var node = this.startNodeAt(startPos, startLoc);
      node.test = expr;
      node.consequent = this.parseMaybeAssign();
      this.expect(types.colon);
      node.alternate = this.parseMaybeAssign(noIn);
      return this.finishNode(node, "ConditionalExpression")
    }
    return expr
  };
  
  // Start the precedence parser.
  
  pp$3.parseExprOps = function(noIn, refDestructuringErrors) {
    var startPos = this.start, startLoc = this.startLoc;
    var expr = this.parseMaybeUnary(refDestructuringErrors, false);
    if (this.checkExpressionErrors(refDestructuringErrors)) { return expr }
    return expr.start == startPos && expr.type === "ArrowFunctionExpression" ? expr : this.parseExprOp(expr, startPos, startLoc, -1, noIn)
  };
  
  // Parse binary operators with the operator precedence parsing
  // algorithm. `left` is the left-hand side of the operator.
  // `minPrec` provides context that allows the function to stop and
  // defer further parser to one of its callers when it encounters an
  // operator that has a lower precedence than the set it is parsing.
  
  pp$3.parseExprOp = function(left, leftStartPos, leftStartLoc, minPrec, noIn) {
    var prec = this.type.binop;
    if (prec != null && (!noIn || this.type !== types._in)) {
      if (prec > minPrec) {
        var logical = this.type === types.logicalOR || this.type === types.logicalAND;
        var op = this.value;
        this.next();
        var startPos = this.start, startLoc = this.startLoc;
        var right = this.parseExprOp(this.parseMaybeUnary(null, false), startPos, startLoc, prec, noIn);
        var node = this.buildBinary(leftStartPos, leftStartLoc, left, right, op, logical);
        return this.parseExprOp(node, leftStartPos, leftStartLoc, minPrec, noIn)
      }
    }
    return left
  };
  
  pp$3.buildBinary = function(startPos, startLoc, left, right, op, logical) {
    var node = this.startNodeAt(startPos, startLoc);
    node.left = left;
    node.operator = op;
    node.right = right;
    return this.finishNode(node, logical ? "LogicalExpression" : "BinaryExpression")
  };
  
  // Parse unary operators, both prefix and postfix.
  
  pp$3.parseMaybeUnary = function(refDestructuringErrors, sawUnary) {
    var this$1 = this;
  
    var startPos = this.start, startLoc = this.startLoc, expr;
    if (this.inAsync && this.isContextual("await")) {
      expr = this.parseAwait();
      sawUnary = true;
    } else if (this.type.prefix) {
      var node = this.startNode(), update = this.type === types.incDec;
      node.operator = this.value;
      node.prefix = true;
      this.next();
      node.argument = this.parseMaybeUnary(null, true);
      this.checkExpressionErrors(refDestructuringErrors, true);
      if (update) { this.checkLVal(node.argument); }
      else if (this.strict && node.operator === "delete" &&
               node.argument.type === "Identifier")
        { this.raiseRecoverable(node.start, "Deleting local variable in strict mode"); }
      else { sawUnary = true; }
      expr = this.finishNode(node, update ? "UpdateExpression" : "UnaryExpression");
    } else {
      expr = this.parseExprSubscripts(refDestructuringErrors);
      if (this.checkExpressionErrors(refDestructuringErrors)) { return expr }
      while (this.type.postfix && !this.canInsertSemicolon()) {
        var node$1 = this$1.startNodeAt(startPos, startLoc);
        node$1.operator = this$1.value;
        node$1.prefix = false;
        node$1.argument = expr;
        this$1.checkLVal(expr);
        this$1.next();
        expr = this$1.finishNode(node$1, "UpdateExpression");
      }
    }
  
    if (!sawUnary && this.eat(types.starstar))
      { return this.buildBinary(startPos, startLoc, expr, this.parseMaybeUnary(null, false), "**", false) }
    else
      { return expr }
  };
  
  // Parse call, dot, and `[]`-subscript expressions.
  
  pp$3.parseExprSubscripts = function(refDestructuringErrors) {
    var startPos = this.start, startLoc = this.startLoc;
    var expr = this.parseExprAtom(refDestructuringErrors);
    var skipArrowSubscripts = expr.type === "ArrowFunctionExpression" && this.input.slice(this.lastTokStart, this.lastTokEnd) !== ")";
    if (this.checkExpressionErrors(refDestructuringErrors) || skipArrowSubscripts) { return expr }
    var result = this.parseSubscripts(expr, startPos, startLoc);
    if (refDestructuringErrors && result.type === "MemberExpression") {
      if (refDestructuringErrors.parenthesizedAssign >= result.start) { refDestructuringErrors.parenthesizedAssign = -1; }
      if (refDestructuringErrors.parenthesizedBind >= result.start) { refDestructuringErrors.parenthesizedBind = -1; }
    }
    return result
  };
  
  pp$3.parseSubscripts = function(base, startPos, startLoc, noCalls) {
    var this$1 = this;
  
    var maybeAsyncArrow = this.options.ecmaVersion >= 8 && base.type === "Identifier" && base.name === "async" &&
        this.lastTokEnd == base.end && !this.canInsertSemicolon();
    for (var computed = (void 0);;) {
      if ((computed = this$1.eat(types.bracketL)) || this$1.eat(types.dot)) {
        var node = this$1.startNodeAt(startPos, startLoc);
        node.object = base;
        node.property = computed ? this$1.parseExpression() : this$1.parseIdent(true);
        node.computed = !!computed;
        if (computed) { this$1.expect(types.bracketR); }
        base = this$1.finishNode(node, "MemberExpression");
      } else if (!noCalls && this$1.eat(types.parenL)) {
        var refDestructuringErrors = new DestructuringErrors, oldYieldPos = this$1.yieldPos, oldAwaitPos = this$1.awaitPos;
        this$1.yieldPos = 0;
        this$1.awaitPos = 0;
        var exprList = this$1.parseExprList(types.parenR, this$1.options.ecmaVersion >= 8, false, refDestructuringErrors);
        if (maybeAsyncArrow && !this$1.canInsertSemicolon() && this$1.eat(types.arrow)) {
          this$1.checkPatternErrors(refDestructuringErrors, false);
          this$1.checkYieldAwaitInDefaultParams();
          this$1.yieldPos = oldYieldPos;
          this$1.awaitPos = oldAwaitPos;
          return this$1.parseArrowExpression(this$1.startNodeAt(startPos, startLoc), exprList, true)
        }
        this$1.checkExpressionErrors(refDestructuringErrors, true);
        this$1.yieldPos = oldYieldPos || this$1.yieldPos;
        this$1.awaitPos = oldAwaitPos || this$1.awaitPos;
        var node$1 = this$1.startNodeAt(startPos, startLoc);
        node$1.callee = base;
        node$1.arguments = exprList;
        base = this$1.finishNode(node$1, "CallExpression");
      } else if (this$1.type === types.backQuote) {
        var node$2 = this$1.startNodeAt(startPos, startLoc);
        node$2.tag = base;
        node$2.quasi = this$1.parseTemplate({isTagged: true});
        base = this$1.finishNode(node$2, "TaggedTemplateExpression");
      } else {
        return base
      }
    }
  };
  
  // Parse an atomic expression — either a single token that is an
  // expression, an expression started by a keyword like `function` or
  // `new`, or an expression wrapped in punctuation like `()`, `[]`,
  // or `{}`.
  
  pp$3.parseExprAtom = function(refDestructuringErrors) {
    var node, canBeArrow = this.potentialArrowAt == this.start;
    switch (this.type) {
    case types._super:
      if (!this.inFunction)
        { this.raise(this.start, "'super' outside of function or class"); }
      node = this.startNode();
      this.next();
      // The `super` keyword can appear at below:
      // SuperProperty:
      //     super [ Expression ]
      //     super . IdentifierName
      // SuperCall:
      //     super Arguments
      if (this.type !== types.dot && this.type !== types.bracketL && this.type !== types.parenL)
        { this.unexpected(); }
      return this.finishNode(node, "Super")
  
    case types._this:
      node = this.startNode();
      this.next();
      return this.finishNode(node, "ThisExpression")
  
    case types.name:
      var startPos = this.start, startLoc = this.startLoc;
      var id = this.parseIdent(this.type !== types.name);
      if (this.options.ecmaVersion >= 8 && id.name === "async" && !this.canInsertSemicolon() && this.eat(types._function))
        { return this.parseFunction(this.startNodeAt(startPos, startLoc), false, false, true) }
      if (canBeArrow && !this.canInsertSemicolon()) {
        if (this.eat(types.arrow))
          { return this.parseArrowExpression(this.startNodeAt(startPos, startLoc), [id], false) }
        if (this.options.ecmaVersion >= 8 && id.name === "async" && this.type === types.name) {
          id = this.parseIdent();
          if (this.canInsertSemicolon() || !this.eat(types.arrow))
            { this.unexpected(); }
          return this.parseArrowExpression(this.startNodeAt(startPos, startLoc), [id], true)
        }
      }
      return id
  
    case types.regexp:
      var value = this.value;
      node = this.parseLiteral(value.value);
      node.regex = {pattern: value.pattern, flags: value.flags};
      return node
  
    case types.num: case types.string:
      return this.parseLiteral(this.value)
  
    case types._null: case types._true: case types._false:
      node = this.startNode();
      node.value = this.type === types._null ? null : this.type === types._true;
      node.raw = this.type.keyword;
      this.next();
      return this.finishNode(node, "Literal")
  
    case types.parenL:
      var start = this.start, expr = this.parseParenAndDistinguishExpression(canBeArrow);
      if (refDestructuringErrors) {
        if (refDestructuringErrors.parenthesizedAssign < 0 && !this.isSimpleAssignTarget(expr))
          { refDestructuringErrors.parenthesizedAssign = start; }
        if (refDestructuringErrors.parenthesizedBind < 0)
          { refDestructuringErrors.parenthesizedBind = start; }
      }
      return expr
  
    case types.bracketL:
      node = this.startNode();
      this.next();
      node.elements = this.parseExprList(types.bracketR, true, true, refDestructuringErrors);
      return this.finishNode(node, "ArrayExpression")
  
    case types.braceL:
      return this.parseObj(false, refDestructuringErrors)
  
    case types._function:
      node = this.startNode();
      this.next();
      return this.parseFunction(node, false)
  
    case types._class:
      return this.parseClass(this.startNode(), false)
  
    case types._new:
      return this.parseNew()
  
    case types.backQuote:
      return this.parseTemplate()
  
    default:
      this.unexpected();
    }
  };
  
  pp$3.parseLiteral = function(value) {
    var node = this.startNode();
    node.value = value;
    node.raw = this.input.slice(this.start, this.end);
    this.next();
    return this.finishNode(node, "Literal")
  };
  
  pp$3.parseParenExpression = function() {
    this.expect(types.parenL);
    var val = this.parseExpression();
    this.expect(types.parenR);
    return val
  };
  
  pp$3.parseParenAndDistinguishExpression = function(canBeArrow) {
    var this$1 = this;
  
    var startPos = this.start, startLoc = this.startLoc, val, allowTrailingComma = this.options.ecmaVersion >= 8;
    if (this.options.ecmaVersion >= 6) {
      this.next();
  
      var innerStartPos = this.start, innerStartLoc = this.startLoc;
      var exprList = [], first = true, lastIsComma = false;
      var refDestructuringErrors = new DestructuringErrors, oldYieldPos = this.yieldPos, oldAwaitPos = this.awaitPos, spreadStart, innerParenStart;
      this.yieldPos = 0;
      this.awaitPos = 0;
      while (this.type !== types.parenR) {
        first ? first = false : this$1.expect(types.comma);
        if (allowTrailingComma && this$1.afterTrailingComma(types.parenR, true)) {
          lastIsComma = true;
          break
        } else if (this$1.type === types.ellipsis) {
          spreadStart = this$1.start;
          exprList.push(this$1.parseParenItem(this$1.parseRestBinding()));
          if (this$1.type === types.comma) { this$1.raise(this$1.start, "Comma is not permitted after the rest element"); }
          break
        } else {
          if (this$1.type === types.parenL && !innerParenStart) {
            innerParenStart = this$1.start;
          }
          exprList.push(this$1.parseMaybeAssign(false, refDestructuringErrors, this$1.parseParenItem));
        }
      }
      var innerEndPos = this.start, innerEndLoc = this.startLoc;
      this.expect(types.parenR);
  
      if (canBeArrow && !this.canInsertSemicolon() && this.eat(types.arrow)) {
        this.checkPatternErrors(refDestructuringErrors, false);
        this.checkYieldAwaitInDefaultParams();
        if (innerParenStart) { this.unexpected(innerParenStart); }
        this.yieldPos = oldYieldPos;
        this.awaitPos = oldAwaitPos;
        return this.parseParenArrowList(startPos, startLoc, exprList)
      }
  
      if (!exprList.length || lastIsComma) { this.unexpected(this.lastTokStart); }
      if (spreadStart) { this.unexpected(spreadStart); }
      this.checkExpressionErrors(refDestructuringErrors, true);
      this.yieldPos = oldYieldPos || this.yieldPos;
      this.awaitPos = oldAwaitPos || this.awaitPos;
  
      if (exprList.length > 1) {
        val = this.startNodeAt(innerStartPos, innerStartLoc);
        val.expressions = exprList;
        this.finishNodeAt(val, "SequenceExpression", innerEndPos, innerEndLoc);
      } else {
        val = exprList[0];
      }
    } else {
      val = this.parseParenExpression();
    }
  
    if (this.options.preserveParens) {
      var par = this.startNodeAt(startPos, startLoc);
      par.expression = val;
      return this.finishNode(par, "ParenthesizedExpression")
    } else {
      return val
    }
  };
  
  pp$3.parseParenItem = function(item) {
    return item
  };
  
  pp$3.parseParenArrowList = function(startPos, startLoc, exprList) {
    return this.parseArrowExpression(this.startNodeAt(startPos, startLoc), exprList)
  };
  
  // New's precedence is slightly tricky. It must allow its argument to
  // be a `[]` or dot subscript expression, but not a call — at least,
  // not without wrapping it in parentheses. Thus, it uses the noCalls
  // argument to parseSubscripts to prevent it from consuming the
  // argument list.
  
  var empty$1 = [];
  
  pp$3.parseNew = function() {
    var node = this.startNode();
    var meta = this.parseIdent(true);
    if (this.options.ecmaVersion >= 6 && this.eat(types.dot)) {
      node.meta = meta;
      node.property = this.parseIdent(true);
      if (node.property.name !== "target")
        { this.raiseRecoverable(node.property.start, "The only valid meta property for new is new.target"); }
      if (!this.inFunction)
        { this.raiseRecoverable(node.start, "new.target can only be used in functions"); }
      return this.finishNode(node, "MetaProperty")
    }
    var startPos = this.start, startLoc = this.startLoc;
    node.callee = this.parseSubscripts(this.parseExprAtom(), startPos, startLoc, true);
    if (this.eat(types.parenL)) { node.arguments = this.parseExprList(types.parenR, this.options.ecmaVersion >= 8, false); }
    else { node.arguments = empty$1; }
    return this.finishNode(node, "NewExpression")
  };
  
  // Parse template expression.
  
  pp$3.parseTemplateElement = function(ref) {
    var isTagged = ref.isTagged;
  
    var elem = this.startNode();
    if (this.type === types.invalidTemplate) {
      if (!isTagged) {
        this.raiseRecoverable(this.start, "Bad escape sequence in untagged template literal");
      }
      elem.value = {
        raw: this.value,
        cooked: null
      };
    } else {
      elem.value = {
        raw: this.input.slice(this.start, this.end).replace(/\r\n?/g, "\n"),
        cooked: this.value
      };
    }
    this.next();
    elem.tail = this.type === types.backQuote;
    return this.finishNode(elem, "TemplateElement")
  };
  
  pp$3.parseTemplate = function(ref) {
    var this$1 = this;
    if ( ref === void 0 ) ref = {};
    var isTagged = ref.isTagged; if ( isTagged === void 0 ) isTagged = false;
  
    var node = this.startNode();
    this.next();
    node.expressions = [];
    var curElt = this.parseTemplateElement({isTagged: isTagged});
    node.quasis = [curElt];
    while (!curElt.tail) {
      this$1.expect(types.dollarBraceL);
      node.expressions.push(this$1.parseExpression());
      this$1.expect(types.braceR);
      node.quasis.push(curElt = this$1.parseTemplateElement({isTagged: isTagged}));
    }
    this.next();
    return this.finishNode(node, "TemplateLiteral")
  };
  
  pp$3.isAsyncProp = function(prop) {
    return !prop.computed && prop.key.type === "Identifier" && prop.key.name === "async" &&
      (this.type === types.name || this.type === types.num || this.type === types.string || this.type === types.bracketL || this.type.keyword) &&
      !lineBreak.test(this.input.slice(this.lastTokEnd, this.start))
  };
  
  // Parse an object literal or binding pattern.
  
  pp$3.parseObj = function(isPattern, refDestructuringErrors) {
    var this$1 = this;
  
    var node = this.startNode(), first = true, propHash = {};
    node.properties = [];
    this.next();
    while (!this.eat(types.braceR)) {
      if (!first) {
        this$1.expect(types.comma);
        if (this$1.afterTrailingComma(types.braceR)) { break }
      } else { first = false; }
  
      var prop = this$1.parseProperty(isPattern, refDestructuringErrors);
      this$1.checkPropClash(prop, propHash);
      node.properties.push(prop);
    }
    return this.finishNode(node, isPattern ? "ObjectPattern" : "ObjectExpression")
  };
  
  pp$3.parseProperty = function(isPattern, refDestructuringErrors) {
    var prop = this.startNode(), isGenerator, isAsync, startPos, startLoc;
    if (this.options.ecmaVersion >= 6) {
      prop.method = false;
      prop.shorthand = false;
      if (isPattern || refDestructuringErrors) {
        startPos = this.start;
        startLoc = this.startLoc;
      }
      if (!isPattern)
        { isGenerator = this.eat(types.star); }
    }
    this.parsePropertyName(prop);
    if (!isPattern && this.options.ecmaVersion >= 8 && !isGenerator && this.isAsyncProp(prop)) {
      isAsync = true;
      this.parsePropertyName(prop, refDestructuringErrors);
    } else {
      isAsync = false;
    }
    this.parsePropertyValue(prop, isPattern, isGenerator, isAsync, startPos, startLoc, refDestructuringErrors);
    return this.finishNode(prop, "Property")
  };
  
  pp$3.parsePropertyValue = function(prop, isPattern, isGenerator, isAsync, startPos, startLoc, refDestructuringErrors) {
    if ((isGenerator || isAsync) && this.type === types.colon)
      { this.unexpected(); }
  
    if (this.eat(types.colon)) {
      prop.value = isPattern ? this.parseMaybeDefault(this.start, this.startLoc) : this.parseMaybeAssign(false, refDestructuringErrors);
      prop.kind = "init";
    } else if (this.options.ecmaVersion >= 6 && this.type === types.parenL) {
      if (isPattern) { this.unexpected(); }
      prop.kind = "init";
      prop.method = true;
      prop.value = this.parseMethod(isGenerator, isAsync);
    } else if (!isPattern &&
               this.options.ecmaVersion >= 5 && !prop.computed && prop.key.type === "Identifier" &&
               (prop.key.name === "get" || prop.key.name === "set") &&
               (this.type != types.comma && this.type != types.braceR)) {
      if (isGenerator || isAsync) { this.unexpected(); }
      prop.kind = prop.key.name;
      this.parsePropertyName(prop);
      prop.value = this.parseMethod(false);
      var paramCount = prop.kind === "get" ? 0 : 1;
      if (prop.value.params.length !== paramCount) {
        var start = prop.value.start;
        if (prop.kind === "get")
          { this.raiseRecoverable(start, "getter should have no params"); }
        else
          { this.raiseRecoverable(start, "setter should have exactly one param"); }
      } else {
        if (prop.kind === "set" && prop.value.params[0].type === "RestElement")
          { this.raiseRecoverable(prop.value.params[0].start, "Setter cannot use rest params"); }
      }
    } else if (this.options.ecmaVersion >= 6 && !prop.computed && prop.key.type === "Identifier") {
      this.checkUnreserved(prop.key);
      prop.kind = "init";
      if (isPattern) {
        prop.value = this.parseMaybeDefault(startPos, startLoc, prop.key);
      } else if (this.type === types.eq && refDestructuringErrors) {
        if (refDestructuringErrors.shorthandAssign < 0)
          { refDestructuringErrors.shorthandAssign = this.start; }
        prop.value = this.parseMaybeDefault(startPos, startLoc, prop.key);
      } else {
        prop.value = prop.key;
      }
      prop.shorthand = true;
    } else { this.unexpected(); }
  };
  
  pp$3.parsePropertyName = function(prop) {
    if (this.options.ecmaVersion >= 6) {
      if (this.eat(types.bracketL)) {
        prop.computed = true;
        prop.key = this.parseMaybeAssign();
        this.expect(types.bracketR);
        return prop.key
      } else {
        prop.computed = false;
      }
    }
    return prop.key = this.type === types.num || this.type === types.string ? this.parseExprAtom() : this.parseIdent(true)
  };
  
  // Initialize empty function node.
  
  pp$3.initFunction = function(node) {
    node.id = null;
    if (this.options.ecmaVersion >= 6) {
      node.generator = false;
      node.expression = false;
    }
    if (this.options.ecmaVersion >= 8)
      { node.async = false; }
  };
  
  // Parse object or class method.
  
  pp$3.parseMethod = function(isGenerator, isAsync) {
    var node = this.startNode(), oldInGen = this.inGenerator, oldInAsync = this.inAsync,
        oldYieldPos = this.yieldPos, oldAwaitPos = this.awaitPos, oldInFunc = this.inFunction;
  
    this.initFunction(node);
    if (this.options.ecmaVersion >= 6)
      { node.generator = isGenerator; }
    if (this.options.ecmaVersion >= 8)
      { node.async = !!isAsync; }
  
    this.inGenerator = node.generator;
    this.inAsync = node.async;
    this.yieldPos = 0;
    this.awaitPos = 0;
    this.inFunction = true;
    this.enterFunctionScope();
  
    this.expect(types.parenL);
    node.params = this.parseBindingList(types.parenR, false, this.options.ecmaVersion >= 8);
    this.checkYieldAwaitInDefaultParams();
    this.parseFunctionBody(node, false);
  
    this.inGenerator = oldInGen;
    this.inAsync = oldInAsync;
    this.yieldPos = oldYieldPos;
    this.awaitPos = oldAwaitPos;
    this.inFunction = oldInFunc;
    return this.finishNode(node, "FunctionExpression")
  };
  
  // Parse arrow function expression with given parameters.
  
  pp$3.parseArrowExpression = function(node, params, isAsync) {
    var oldInGen = this.inGenerator, oldInAsync = this.inAsync,
        oldYieldPos = this.yieldPos, oldAwaitPos = this.awaitPos, oldInFunc = this.inFunction;
  
    this.enterFunctionScope();
    this.initFunction(node);
    if (this.options.ecmaVersion >= 8)
      { node.async = !!isAsync; }
  
    this.inGenerator = false;
    this.inAsync = node.async;
    this.yieldPos = 0;
    this.awaitPos = 0;
    this.inFunction = true;
  
    node.params = this.toAssignableList(params, true);
    this.parseFunctionBody(node, true);
  
    this.inGenerator = oldInGen;
    this.inAsync = oldInAsync;
    this.yieldPos = oldYieldPos;
    this.awaitPos = oldAwaitPos;
    this.inFunction = oldInFunc;
    return this.finishNode(node, "ArrowFunctionExpression")
  };
  
  // Parse function body and check parameters.
  
  pp$3.parseFunctionBody = function(node, isArrowFunction) {
    var isExpression = isArrowFunction && this.type !== types.braceL;
    var oldStrict = this.strict, useStrict = false;
  
    if (isExpression) {
      node.body = this.parseMaybeAssign();
      node.expression = true;
      this.checkParams(node, false);
    } else {
      var nonSimple = this.options.ecmaVersion >= 7 && !this.isSimpleParamList(node.params);
      if (!oldStrict || nonSimple) {
        useStrict = this.strictDirective(this.end);
        // If this is a strict mode function, verify that argument names
        // are not repeated, and it does not try to bind the words `eval`
        // or `arguments`.
        if (useStrict && nonSimple)
          { this.raiseRecoverable(node.start, "Illegal 'use strict' directive in function with non-simple parameter list"); }
      }
      // Start a new scope with regard to labels and the `inFunction`
      // flag (restore them to their old value afterwards).
      var oldLabels = this.labels;
      this.labels = [];
      if (useStrict) { this.strict = true; }
  
      // Add the params to varDeclaredNames to ensure that an error is thrown
      // if a let/const declaration in the function clashes with one of the params.
      this.checkParams(node, !oldStrict && !useStrict && !isArrowFunction && this.isSimpleParamList(node.params));
      node.body = this.parseBlock(false);
      node.expression = false;
      this.adaptDirectivePrologue(node.body.body);
      this.labels = oldLabels;
    }
    this.exitFunctionScope();
  
    if (this.strict && node.id) {
      // Ensure the function name isn't a forbidden identifier in strict mode, e.g. 'eval'
      this.checkLVal(node.id, "none");
    }
    this.strict = oldStrict;
  };
  
  pp$3.isSimpleParamList = function(params) {
    for (var i = 0, list = params; i < list.length; i += 1)
      {
      var param = list[i];
  
      if (param.type !== "Identifier") { return false
    } }
    return true
  };
  
  // Checks function params for various disallowed patterns such as using "eval"
  // or "arguments" and duplicate parameters.
  
  pp$3.checkParams = function(node, allowDuplicates) {
    var this$1 = this;
  
    var nameHash = {};
    for (var i = 0, list = node.params; i < list.length; i += 1)
      {
      var param = list[i];
  
      this$1.checkLVal(param, "var", allowDuplicates ? null : nameHash);
    }
  };
  
  // Parses a comma-separated list of expressions, and returns them as
  // an array. `close` is the token type that ends the list, and
  // `allowEmpty` can be turned on to allow subsequent commas with
  // nothing in between them to be parsed as `null` (which is needed
  // for array literals).
  
  pp$3.parseExprList = function(close, allowTrailingComma, allowEmpty, refDestructuringErrors) {
    var this$1 = this;
  
    var elts = [], first = true;
    while (!this.eat(close)) {
      if (!first) {
        this$1.expect(types.comma);
        if (allowTrailingComma && this$1.afterTrailingComma(close)) { break }
      } else { first = false; }
  
      var elt = (void 0);
      if (allowEmpty && this$1.type === types.comma)
        { elt = null; }
      else if (this$1.type === types.ellipsis) {
        elt = this$1.parseSpread(refDestructuringErrors);
        if (refDestructuringErrors && this$1.type === types.comma && refDestructuringErrors.trailingComma < 0)
          { refDestructuringErrors.trailingComma = this$1.start; }
      } else {
        elt = this$1.parseMaybeAssign(false, refDestructuringErrors);
      }
      elts.push(elt);
    }
    return elts
  };
  
  pp$3.checkUnreserved = function(ref) {
    var start = ref.start;
    var end = ref.end;
    var name = ref.name;
  
    if (this.inGenerator && name === "yield")
      { this.raiseRecoverable(start, "Can not use 'yield' as identifier inside a generator"); }
    if (this.inAsync && name === "await")
      { this.raiseRecoverable(start, "Can not use 'await' as identifier inside an async function"); }
    if (this.isKeyword(name))
      { this.raise(start, ("Unexpected keyword '" + name + "'")); }
    if (this.options.ecmaVersion < 6 &&
      this.input.slice(start, end).indexOf("\\") != -1) { return }
    var re = this.strict ? this.reservedWordsStrict : this.reservedWords;
    if (re.test(name))
      { this.raiseRecoverable(start, ("The keyword '" + name + "' is reserved")); }
  };
  
  // Parse the next token as an identifier. If `liberal` is true (used
  // when parsing properties), it will also convert keywords into
  // identifiers.
  
  pp$3.parseIdent = function(liberal, isBinding) {
    var node = this.startNode();
    if (liberal && this.options.allowReserved == "never") { liberal = false; }
    if (this.type === types.name) {
      node.name = this.value;
    } else if (this.type.keyword) {
      node.name = this.type.keyword;
  
      // To fix https://github.com/ternjs/acorn/issues/575
      // `class` and `function` keywords push new context into this.context.
      // But there is no chance to pop the context if the keyword is consumed as an identifier such as a property name.
      // If the previous token is a dot, this does not apply because the context-managing code already ignored the keyword
      if ((node.name === "class" || node.name === "function") &&
          (this.lastTokEnd !== this.lastTokStart + 1 || this.input.charCodeAt(this.lastTokStart) !== 46)) {
        this.context.pop();
      }
    } else {
      this.unexpected();
    }
    this.next();
    this.finishNode(node, "Identifier");
    if (!liberal) { this.checkUnreserved(node); }
    return node
  };
  
  // Parses yield expression inside generator.
  
  pp$3.parseYield = function() {
    if (!this.yieldPos) { this.yieldPos = this.start; }
  
    var node = this.startNode();
    this.next();
    if (this.type == types.semi || this.canInsertSemicolon() || (this.type != types.star && !this.type.startsExpr)) {
      node.delegate = false;
      node.argument = null;
    } else {
      node.delegate = this.eat(types.star);
      node.argument = this.parseMaybeAssign();
    }
    return this.finishNode(node, "YieldExpression")
  };
  
  pp$3.parseAwait = function() {
    if (!this.awaitPos) { this.awaitPos = this.start; }
  
    var node = this.startNode();
    this.next();
    node.argument = this.parseMaybeUnary(null, true);
    return this.finishNode(node, "AwaitExpression")
  };
  
  var pp$4 = Parser.prototype;
  
  // This function is used to raise exceptions on parse errors. It
  // takes an offset integer (into the current `input`) to indicate
  // the location of the error, attaches the position to the end
  // of the error message, and then raises a `SyntaxError` with that
  // message.
  
  pp$4.raise = function(pos, message) {
    var loc = getLineInfo(this.input, pos);
    message += " (" + loc.line + ":" + loc.column + ")";
    var err = new SyntaxError(message);
    err.pos = pos; err.loc = loc; err.raisedAt = this.pos;
    throw err
  };
  
  pp$4.raiseRecoverable = pp$4.raise;
  
  pp$4.curPosition = function() {
    if (this.options.locations) {
      return new Position(this.curLine, this.pos - this.lineStart)
    }
  };
  
  var pp$5 = Parser.prototype;
  
  // Object.assign polyfill
  var assign = Object.assign || function(target) {
    var sources = [], len = arguments.length - 1;
    while ( len-- > 0 ) sources[ len ] = arguments[ len + 1 ];
  
    for (var i = 0, list = sources; i < list.length; i += 1) {
      var source = list[i];
  
      for (var key in source) {
        if (has(source, key)) {
          target[key] = source[key];
        }
      }
    }
    return target
  };
  
  // The functions in this module keep track of declared variables in the current scope in order to detect duplicate variable names.
  
  pp$5.enterFunctionScope = function() {
    // var: a hash of var-declared names in the current lexical scope
    // lexical: a hash of lexically-declared names in the current lexical scope
    // childVar: a hash of var-declared names in all child lexical scopes of the current lexical scope (within the current function scope)
    // parentLexical: a hash of lexically-declared names in all parent lexical scopes of the current lexical scope (within the current function scope)
    this.scopeStack.push({var: {}, lexical: {}, childVar: {}, parentLexical: {}});
  };
  
  pp$5.exitFunctionScope = function() {
    this.scopeStack.pop();
  };
  
  pp$5.enterLexicalScope = function() {
    var parentScope = this.scopeStack[this.scopeStack.length - 1];
    var childScope = {var: {}, lexical: {}, childVar: {}, parentLexical: {}};
  
    this.scopeStack.push(childScope);
    assign(childScope.parentLexical, parentScope.lexical, parentScope.parentLexical);
  };
  
  pp$5.exitLexicalScope = function() {
    var childScope = this.scopeStack.pop();
    var parentScope = this.scopeStack[this.scopeStack.length - 1];
  
    assign(parentScope.childVar, childScope.var, childScope.childVar);
  };
  
  /**
   * A name can be declared with `var` if there are no variables with the same name declared with `let`/`const`
   * in the current lexical scope or any of the parent lexical scopes in this function.
   */
  pp$5.canDeclareVarName = function(name) {
    var currentScope = this.scopeStack[this.scopeStack.length - 1];
  
    return !has(currentScope.lexical, name) && !has(currentScope.parentLexical, name)
  };
  
  /**
   * A name can be declared with `let`/`const` if there are no variables with the same name declared with `let`/`const`
   * in the current scope, and there are no variables with the same name declared with `var` in the current scope or in
   * any child lexical scopes in this function.
   */
  pp$5.canDeclareLexicalName = function(name) {
    var currentScope = this.scopeStack[this.scopeStack.length - 1];
  
    return !has(currentScope.lexical, name) && !has(currentScope.var, name) && !has(currentScope.childVar, name)
  };
  
  pp$5.declareVarName = function(name) {
    this.scopeStack[this.scopeStack.length - 1].var[name] = true;
  };
  
  pp$5.declareLexicalName = function(name) {
    this.scopeStack[this.scopeStack.length - 1].lexical[name] = true;
  };
  
  var Node = function Node(parser, pos, loc) {
    this.type = "";
    this.start = pos;
    this.end = 0;
    if (parser.options.locations)
      { this.loc = new SourceLocation(parser, loc); }
    if (parser.options.directSourceFile)
      { this.sourceFile = parser.options.directSourceFile; }
    if (parser.options.ranges)
      { this.range = [pos, 0]; }
  };
  
  // Start an AST node, attaching a start offset.
  
  var pp$6 = Parser.prototype;
  
  pp$6.startNode = function() {
    return new Node(this, this.start, this.startLoc)
  };
  
  pp$6.startNodeAt = function(pos, loc) {
    return new Node(this, pos, loc)
  };
  
  // Finish an AST node, adding `type` and `end` properties.
  
  function finishNodeAt(node, type, pos, loc) {
    node.type = type;
    node.end = pos;
    if (this.options.locations)
      { node.loc.end = loc; }
    if (this.options.ranges)
      { node.range[1] = pos; }
    return node
  }
  
  pp$6.finishNode = function(node, type) {
    return finishNodeAt.call(this, node, type, this.lastTokEnd, this.lastTokEndLoc)
  };
  
  // Finish node at given position
  
  pp$6.finishNodeAt = function(node, type, pos, loc) {
    return finishNodeAt.call(this, node, type, pos, loc)
  };
  
  // The algorithm used to determine whether a regexp can appear at a
  // given point in the program is loosely based on sweet.js' approach.
  // See https://github.com/mozilla/sweet.js/wiki/design
  
  var TokContext = function TokContext(token, isExpr, preserveSpace, override, generator) {
    this.token = token;
    this.isExpr = !!isExpr;
    this.preserveSpace = !!preserveSpace;
    this.override = override;
    this.generator = !!generator;
  };
  
  var types$1 = {
    b_stat: new TokContext("{", false),
    b_expr: new TokContext("{", true),
    b_tmpl: new TokContext("${", false),
    p_stat: new TokContext("(", false),
    p_expr: new TokContext("(", true),
    q_tmpl: new TokContext("`", true, true, function (p) { return p.tryReadTemplateToken(); }),
    f_stat: new TokContext("function", false),
    f_expr: new TokContext("function", true),
    f_expr_gen: new TokContext("function", true, false, null, true),
    f_gen: new TokContext("function", false, false, null, true)
  };
  
  var pp$7 = Parser.prototype;
  
  pp$7.initialContext = function() {
    return [types$1.b_stat]
  };
  
  pp$7.braceIsBlock = function(prevType) {
    var parent = this.curContext();
    if (parent === types$1.f_expr || parent === types$1.f_stat)
      { return true }
    if (prevType === types.colon && (parent === types$1.b_stat || parent === types$1.b_expr))
      { return !parent.isExpr }
  
    // The check for `tt.name && exprAllowed` detects whether we are
    // after a `yield` or `of` construct. See the `updateContext` for
    // `tt.name`.
    if (prevType === types._return || prevType == types.name && this.exprAllowed)
      { return lineBreak.test(this.input.slice(this.lastTokEnd, this.start)) }
    if (prevType === types._else || prevType === types.semi || prevType === types.eof || prevType === types.parenR || prevType == types.arrow)
      { return true }
    if (prevType == types.braceL)
      { return parent === types$1.b_stat }
    if (prevType == types._var || prevType == types.name)
      { return false }
    return !this.exprAllowed
  };
  
  pp$7.inGeneratorContext = function() {
    var this$1 = this;
  
    for (var i = this.context.length - 1; i >= 1; i--) {
      var context = this$1.context[i];
      if (context.token === "function")
        { return context.generator }
    }
    return false
  };
  
  pp$7.updateContext = function(prevType) {
    var update, type = this.type;
    if (type.keyword && prevType == types.dot)
      { this.exprAllowed = false; }
    else if (update = type.updateContext)
      { update.call(this, prevType); }
    else
      { this.exprAllowed = type.beforeExpr; }
  };
  
  // Token-specific context update code
  
  types.parenR.updateContext = types.braceR.updateContext = function() {
    if (this.context.length == 1) {
      this.exprAllowed = true;
      return
    }
    var out = this.context.pop();
    if (out === types$1.b_stat && this.curContext().token === "function") {
      out = this.context.pop();
    }
    this.exprAllowed = !out.isExpr;
  };
  
  types.braceL.updateContext = function(prevType) {
    this.context.push(this.braceIsBlock(prevType) ? types$1.b_stat : types$1.b_expr);
    this.exprAllowed = true;
  };
  
  types.dollarBraceL.updateContext = function() {
    this.context.push(types$1.b_tmpl);
    this.exprAllowed = true;
  };
  
  types.parenL.updateContext = function(prevType) {
    var statementParens = prevType === types._if || prevType === types._for || prevType === types._with || prevType === types._while;
    this.context.push(statementParens ? types$1.p_stat : types$1.p_expr);
    this.exprAllowed = true;
  };
  
  types.incDec.updateContext = function() {
    // tokExprAllowed stays unchanged
  };
  
  types._function.updateContext = types._class.updateContext = function(prevType) {
    if (prevType.beforeExpr && prevType !== types.semi && prevType !== types._else &&
        !((prevType === types.colon || prevType === types.braceL) && this.curContext() === types$1.b_stat))
      { this.context.push(types$1.f_expr); }
    else
      { this.context.push(types$1.f_stat); }
    this.exprAllowed = false;
  };
  
  types.backQuote.updateContext = function() {
    if (this.curContext() === types$1.q_tmpl)
      { this.context.pop(); }
    else
      { this.context.push(types$1.q_tmpl); }
    this.exprAllowed = false;
  };
  
  types.star.updateContext = function(prevType) {
    if (prevType == types._function) {
      var index = this.context.length - 1;
      if (this.context[index] === types$1.f_expr)
        { this.context[index] = types$1.f_expr_gen; }
      else
        { this.context[index] = types$1.f_gen; }
    }
    this.exprAllowed = true;
  };
  
  types.name.updateContext = function(prevType) {
    var allowed = false;
    if (this.options.ecmaVersion >= 6) {
      if (this.value == "of" && !this.exprAllowed ||
          this.value == "yield" && this.inGeneratorContext())
        { allowed = true; }
    }
    this.exprAllowed = allowed;
  };
  
  // Object type used to represent tokens. Note that normally, tokens
  // simply exist as properties on the parser object. This is only
  // used for the onToken callback and the external tokenizer.
  
  var Token = function Token(p) {
    this.type = p.type;
    this.value = p.value;
    this.start = p.start;
    this.end = p.end;
    if (p.options.locations)
      { this.loc = new SourceLocation(p, p.startLoc, p.endLoc); }
    if (p.options.ranges)
      { this.range = [p.start, p.end]; }
  };
  
  // ## Tokenizer
  
  var pp$8 = Parser.prototype;
  
  // Are we running under Rhino?
  var isRhino = typeof Packages == "object" && Object.prototype.toString.call(Packages) == "[object JavaPackage]";
  
  // Move to the next token
  
  pp$8.next = function() {
    if (this.options.onToken)
      { this.options.onToken(new Token(this)); }
  
    this.lastTokEnd = this.end;
    this.lastTokStart = this.start;
    this.lastTokEndLoc = this.endLoc;
    this.lastTokStartLoc = this.startLoc;
    this.nextToken();
  };
  
  pp$8.getToken = function() {
    this.next();
    return new Token(this)
  };
  
  // If we're in an ES6 environment, make parsers iterable
  if (typeof Symbol !== "undefined")
    { pp$8[Symbol.iterator] = function() {
      var this$1 = this;
  
      return {
        next: function () {
          var token = this$1.getToken();
          return {
            done: token.type === types.eof,
            value: token
          }
        }
      }
    }; }
  
  // Toggle strict mode. Re-reads the next number or string to please
  // pedantic tests (`"use strict"; 010;` should fail).
  
  pp$8.curContext = function() {
    return this.context[this.context.length - 1]
  };
  
  // Read a single token, updating the parser object's token-related
  // properties.
  
  pp$8.nextToken = function() {
    var curContext = this.curContext();
    if (!curContext || !curContext.preserveSpace) { this.skipSpace(); }
  
    this.start = this.pos;
    if (this.options.locations) { this.startLoc = this.curPosition(); }
    if (this.pos >= this.input.length) { return this.finishToken(types.eof) }
  
    if (curContext.override) { return curContext.override(this) }
    else { this.readToken(this.fullCharCodeAtPos()); }
  };
  
  pp$8.readToken = function(code) {
    // Identifier or keyword. '\uXXXX' sequences are allowed in
    // identifiers, so '\' also dispatches to that.
    if (isIdentifierStart(code, this.options.ecmaVersion >= 6) || code === 92 /* '\' */)
      { return this.readWord() }
  
    return this.getTokenFromCode(code)
  };
  
  pp$8.fullCharCodeAtPos = function() {
    var code = this.input.charCodeAt(this.pos);
    if (code <= 0xd7ff || code >= 0xe000) { return code }
    var next = this.input.charCodeAt(this.pos + 1);
    return (code << 10) + next - 0x35fdc00
  };
  
  pp$8.skipBlockComment = function() {
    var this$1 = this;
  
    var startLoc = this.options.onComment && this.curPosition();
    var start = this.pos, end = this.input.indexOf("*/", this.pos += 2);
    if (end === -1) { this.raise(this.pos - 2, "Unterminated comment"); }
    this.pos = end + 2;
    if (this.options.locations) {
      lineBreakG.lastIndex = start;
      var match;
      while ((match = lineBreakG.exec(this.input)) && match.index < this.pos) {
        ++this$1.curLine;
        this$1.lineStart = match.index + match[0].length;
      }
    }
    if (this.options.onComment)
      { this.options.onComment(true, this.input.slice(start + 2, end), start, this.pos,
                             startLoc, this.curPosition()); }
  };
  
  pp$8.skipLineComment = function(startSkip) {
    var this$1 = this;
  
    var start = this.pos;
    var startLoc = this.options.onComment && this.curPosition();
    var ch = this.input.charCodeAt(this.pos += startSkip);
    while (this.pos < this.input.length && !isNewLine(ch)) {
      ch = this$1.input.charCodeAt(++this$1.pos);
    }
    if (this.options.onComment)
      { this.options.onComment(false, this.input.slice(start + startSkip, this.pos), start, this.pos,
                             startLoc, this.curPosition()); }
  };
  
  // Called at the start of the parse and after every token. Skips
  // whitespace and comments, and.
  
  pp$8.skipSpace = function() {
    var this$1 = this;
  
    loop: while (this.pos < this.input.length) {
      var ch = this$1.input.charCodeAt(this$1.pos);
      switch (ch) {
      case 32: case 160: // ' '
        ++this$1.pos;
        break
      case 13:
        if (this$1.input.charCodeAt(this$1.pos + 1) === 10) {
          ++this$1.pos;
        }
      case 10: case 8232: case 8233:
        ++this$1.pos;
        if (this$1.options.locations) {
          ++this$1.curLine;
          this$1.lineStart = this$1.pos;
        }
        break
      case 47: // '/'
        switch (this$1.input.charCodeAt(this$1.pos + 1)) {
        case 42: // '*'
          this$1.skipBlockComment();
          break
        case 47:
          this$1.skipLineComment(2);
          break
        default:
          break loop
        }
        break
      default:
        if (ch > 8 && ch < 14 || ch >= 5760 && nonASCIIwhitespace.test(String.fromCharCode(ch))) {
          ++this$1.pos;
        } else {
          break loop
        }
      }
    }
  };
  
  // Called at the end of every token. Sets `end`, `val`, and
  // maintains `context` and `exprAllowed`, and skips the space after
  // the token, so that the next one's `start` will point at the
  // right position.
  
  pp$8.finishToken = function(type, val) {
    this.end = this.pos;
    if (this.options.locations) { this.endLoc = this.curPosition(); }
    var prevType = this.type;
    this.type = type;
    this.value = val;
  
    this.updateContext(prevType);
  };
  
  // ### Token reading
  
  // This is the function that is called to fetch the next token. It
  // is somewhat obscure, because it works in character codes rather
  // than characters, and because operator parsing has been inlined
  // into it.
  //
  // All in the name of speed.
  //
  pp$8.readToken_dot = function() {
    var next = this.input.charCodeAt(this.pos + 1);
    if (next >= 48 && next <= 57) { return this.readNumber(true) }
    var next2 = this.input.charCodeAt(this.pos + 2);
    if (this.options.ecmaVersion >= 6 && next === 46 && next2 === 46) { // 46 = dot '.'
      this.pos += 3;
      return this.finishToken(types.ellipsis)
    } else {
      ++this.pos;
      return this.finishToken(types.dot)
    }
  };
  
  pp$8.readToken_slash = function() { // '/'
    var next = this.input.charCodeAt(this.pos + 1);
    if (this.exprAllowed) { ++this.pos; return this.readRegexp() }
    if (next === 61) { return this.finishOp(types.assign, 2) }
    return this.finishOp(types.slash, 1)
  };
  
  pp$8.readToken_mult_modulo_exp = function(code) { // '%*'
    var next = this.input.charCodeAt(this.pos + 1);
    var size = 1;
    var tokentype = code === 42 ? types.star : types.modulo;
  
    // exponentiation operator ** and **=
    if (this.options.ecmaVersion >= 7 && code == 42 && next === 42) {
      ++size;
      tokentype = types.starstar;
      next = this.input.charCodeAt(this.pos + 2);
    }
  
    if (next === 61) { return this.finishOp(types.assign, size + 1) }
    return this.finishOp(tokentype, size)
  };
  
  pp$8.readToken_pipe_amp = function(code) { // '|&'
    var next = this.input.charCodeAt(this.pos + 1);
    if (next === code) { return this.finishOp(code === 124 ? types.logicalOR : types.logicalAND, 2) }
    if (next === 61) { return this.finishOp(types.assign, 2) }
    return this.finishOp(code === 124 ? types.bitwiseOR : types.bitwiseAND, 1)
  };
  
  pp$8.readToken_caret = function() { // '^'
    var next = this.input.charCodeAt(this.pos + 1);
    if (next === 61) { return this.finishOp(types.assign, 2) }
    return this.finishOp(types.bitwiseXOR, 1)
  };
  
  pp$8.readToken_plus_min = function(code) { // '+-'
    var next = this.input.charCodeAt(this.pos + 1);
    if (next === code) {
      if (next == 45 && !this.inModule && this.input.charCodeAt(this.pos + 2) == 62 &&
          (this.lastTokEnd === 0 || lineBreak.test(this.input.slice(this.lastTokEnd, this.pos)))) {
        // A `-->` line comment
        this.skipLineComment(3);
        this.skipSpace();
        return this.nextToken()
      }
      return this.finishOp(types.incDec, 2)
    }
    if (next === 61) { return this.finishOp(types.assign, 2) }
    return this.finishOp(types.plusMin, 1)
  };
  
  pp$8.readToken_lt_gt = function(code) { // '<>'
    var next = this.input.charCodeAt(this.pos + 1);
    var size = 1;
    if (next === code) {
      size = code === 62 && this.input.charCodeAt(this.pos + 2) === 62 ? 3 : 2;
      if (this.input.charCodeAt(this.pos + size) === 61) { return this.finishOp(types.assign, size + 1) }
      return this.finishOp(types.bitShift, size)
    }
    if (next == 33 && code == 60 && !this.inModule && this.input.charCodeAt(this.pos + 2) == 45 &&
        this.input.charCodeAt(this.pos + 3) == 45) {
      // `<!--`, an XML-style comment that should be interpreted as a line comment
      this.skipLineComment(4);
      this.skipSpace();
      return this.nextToken()
    }
    if (next === 61) { size = 2; }
    return this.finishOp(types.relational, size)
  };
  
  pp$8.readToken_eq_excl = function(code) { // '=!'
    var next = this.input.charCodeAt(this.pos + 1);
    if (next === 61) { return this.finishOp(types.equality, this.input.charCodeAt(this.pos + 2) === 61 ? 3 : 2) }
    if (code === 61 && next === 62 && this.options.ecmaVersion >= 6) { // '=>'
      this.pos += 2;
      return this.finishToken(types.arrow)
    }
    return this.finishOp(code === 61 ? types.eq : types.prefix, 1)
  };
  
  pp$8.getTokenFromCode = function(code) {
    switch (code) {
      // The interpretation of a dot depends on whether it is followed
      // by a digit or another two dots.
    case 46: // '.'
      return this.readToken_dot()
  
      // Punctuation tokens.
    case 40: ++this.pos; return this.finishToken(types.parenL)
    case 41: ++this.pos; return this.finishToken(types.parenR)
    case 59: ++this.pos; return this.finishToken(types.semi)
    case 44: ++this.pos; return this.finishToken(types.comma)
    case 91: ++this.pos; return this.finishToken(types.bracketL)
    case 93: ++this.pos; return this.finishToken(types.bracketR)
    case 123: ++this.pos; return this.finishToken(types.braceL)
    case 125: ++this.pos; return this.finishToken(types.braceR)
    case 58: ++this.pos; return this.finishToken(types.colon)
    case 63: ++this.pos; return this.finishToken(types.question)
  
    case 96: // '`'
      if (this.options.ecmaVersion < 6) { break }
      ++this.pos;
      return this.finishToken(types.backQuote)
  
    case 48: // '0'
      var next = this.input.charCodeAt(this.pos + 1);
      if (next === 120 || next === 88) { return this.readRadixNumber(16) } // '0x', '0X' - hex number
      if (this.options.ecmaVersion >= 6) {
        if (next === 111 || next === 79) { return this.readRadixNumber(8) } // '0o', '0O' - octal number
        if (next === 98 || next === 66) { return this.readRadixNumber(2) } // '0b', '0B' - binary number
      }
      // Anything else beginning with a digit is an integer, octal
      // number, or float.
    case 49: case 50: case 51: case 52: case 53: case 54: case 55: case 56: case 57: // 1-9
      return this.readNumber(false)
  
      // Quotes produce strings.
    case 34: case 39: // '"', "'"
      return this.readString(code)
  
      // Operators are parsed inline in tiny state machines. '=' (61) is
      // often referred to. `finishOp` simply skips the amount of
      // characters it is given as second argument, and returns a token
      // of the type given by its first argument.
  
    case 47: // '/'
      return this.readToken_slash()
  
    case 37: case 42: // '%*'
      return this.readToken_mult_modulo_exp(code)
  
    case 124: case 38: // '|&'
      return this.readToken_pipe_amp(code)
  
    case 94: // '^'
      return this.readToken_caret()
  
    case 43: case 45: // '+-'
      return this.readToken_plus_min(code)
  
    case 60: case 62: // '<>'
      return this.readToken_lt_gt(code)
  
    case 61: case 33: // '=!'
      return this.readToken_eq_excl(code)
  
    case 126: // '~'
      return this.finishOp(types.prefix, 1)
    }
  
    this.raise(this.pos, "Unexpected character '" + codePointToString(code) + "'");
  };
  
  pp$8.finishOp = function(type, size) {
    var str = this.input.slice(this.pos, this.pos + size);
    this.pos += size;
    return this.finishToken(type, str)
  };
  
  // Parse a regular expression. Some context-awareness is necessary,
  // since a '/' inside a '[]' set does not end the expression.
  
  function tryCreateRegexp(src, flags, throwErrorAt, parser) {
    try {
      return new RegExp(src, flags)
    } catch (e) {
      if (throwErrorAt !== undefined) {
        if (e instanceof SyntaxError) { parser.raise(throwErrorAt, "Error parsing regular expression: " + e.message); }
        throw e
      }
    }
  }
  
  var regexpUnicodeSupport = !!tryCreateRegexp("\uffff", "u");
  
  pp$8.readRegexp = function() {
    var this$1 = this;
  
    var escaped, inClass, start = this.pos;
    for (;;) {
      if (this$1.pos >= this$1.input.length) { this$1.raise(start, "Unterminated regular expression"); }
      var ch = this$1.input.charAt(this$1.pos);
      if (lineBreak.test(ch)) { this$1.raise(start, "Unterminated regular expression"); }
      if (!escaped) {
        if (ch === "[") { inClass = true; }
        else if (ch === "]" && inClass) { inClass = false; }
        else if (ch === "/" && !inClass) { break }
        escaped = ch === "\\";
      } else { escaped = false; }
      ++this$1.pos;
    }
    var content = this.input.slice(start, this.pos);
    ++this.pos;
    // Need to use `readWord1` because '\uXXXX' sequences are allowed
    // here (don't ask).
    var mods = this.readWord1();
    var tmp = content, tmpFlags = "";
    if (mods) {
      var validFlags = /^[gim]*$/;
      if (this.options.ecmaVersion >= 6) { validFlags = /^[gimuy]*$/; }
      if (!validFlags.test(mods)) { this.raise(start, "Invalid regular expression flag"); }
      if (mods.indexOf("u") >= 0) {
        if (regexpUnicodeSupport) {
          tmpFlags = "u";
        } else {
          // Replace each astral symbol and every Unicode escape sequence that
          // possibly represents an astral symbol or a paired surrogate with a
          // single ASCII symbol to avoid throwing on regular expressions that
          // are only valid in combination with the `/u` flag.
          // Note: replacing with the ASCII symbol `x` might cause false
          // negatives in unlikely scenarios. For example, `[\u{61}-b]` is a
          // perfectly valid pattern that is equivalent to `[a-b]`, but it would
          // be replaced by `[x-b]` which throws an error.
          tmp = tmp.replace(/\\u\{([0-9a-fA-F]+)\}/g, function (_match, code, offset) {
            code = Number("0x" + code);
            if (code > 0x10FFFF) { this$1.raise(start + offset + 3, "Code point out of bounds"); }
            return "x"
          });
          tmp = tmp.replace(/\\u([a-fA-F0-9]{4})|[\uD800-\uDBFF][\uDC00-\uDFFF]/g, "x");
          tmpFlags = tmpFlags.replace("u", "");
        }
      }
    }
    // Detect invalid regular expressions.
    var value = null;
    // Rhino's regular expression parser is flaky and throws uncatchable exceptions,
    // so don't do detection if we are running under Rhino
    if (!isRhino) {
      tryCreateRegexp(tmp, tmpFlags, start, this);
      // Get a regular expression object for this pattern-flag pair, or `null` in
      // case the current environment doesn't support the flags it uses.
      value = tryCreateRegexp(content, mods);
    }
    return this.finishToken(types.regexp, {pattern: content, flags: mods, value: value})
  };
  
  // Read an integer in the given radix. Return null if zero digits
  // were read, the integer value otherwise. When `len` is given, this
  // will return `null` unless the integer has exactly `len` digits.
  
  pp$8.readInt = function(radix, len) {
    var this$1 = this;
  
    var start = this.pos, total = 0;
    for (var i = 0, e = len == null ? Infinity : len; i < e; ++i) {
      var code = this$1.input.charCodeAt(this$1.pos), val = (void 0);
      if (code >= 97) { val = code - 97 + 10; } // a
      else if (code >= 65) { val = code - 65 + 10; } // A
      else if (code >= 48 && code <= 57) { val = code - 48; } // 0-9
      else { val = Infinity; }
      if (val >= radix) { break }
      ++this$1.pos;
      total = total * radix + val;
    }
    if (this.pos === start || len != null && this.pos - start !== len) { return null }
  
    return total
  };
  
  pp$8.readRadixNumber = function(radix) {
    this.pos += 2; // 0x
    var val = this.readInt(radix);
    if (val == null) { this.raise(this.start + 2, "Expected number in radix " + radix); }
    if (isIdentifierStart(this.fullCharCodeAtPos())) { this.raise(this.pos, "Identifier directly after number"); }
    return this.finishToken(types.num, val)
  };
  
  // Read an integer, octal integer, or floating-point number.
  
  pp$8.readNumber = function(startsWithDot) {
    var start = this.pos, isFloat = false, octal = this.input.charCodeAt(this.pos) === 48;
    if (!startsWithDot && this.readInt(10) === null) { this.raise(start, "Invalid number"); }
    if (octal && this.pos == start + 1) { octal = false; }
    var next = this.input.charCodeAt(this.pos);
    if (next === 46 && !octal) { // '.'
      ++this.pos;
      this.readInt(10);
      isFloat = true;
      next = this.input.charCodeAt(this.pos);
    }
    if ((next === 69 || next === 101) && !octal) { // 'eE'
      next = this.input.charCodeAt(++this.pos);
      if (next === 43 || next === 45) { ++this.pos; } // '+-'
      if (this.readInt(10) === null) { this.raise(start, "Invalid number"); }
      isFloat = true;
    }
    if (isIdentifierStart(this.fullCharCodeAtPos())) { this.raise(this.pos, "Identifier directly after number"); }
  
    var str = this.input.slice(start, this.pos), val;
    if (isFloat) { val = parseFloat(str); }
    else if (!octal || str.length === 1) { val = parseInt(str, 10); }
    else if (this.strict) { this.raise(start, "Invalid number"); }
    else if (/[89]/.test(str)) { val = parseInt(str, 10); }
    else { val = parseInt(str, 8); }
    return this.finishToken(types.num, val)
  };
  
  // Read a string value, interpreting backslash-escapes.
  
  pp$8.readCodePoint = function() {
    var ch = this.input.charCodeAt(this.pos), code;
  
    if (ch === 123) { // '{'
      if (this.options.ecmaVersion < 6) { this.unexpected(); }
      var codePos = ++this.pos;
      code = this.readHexChar(this.input.indexOf("}", this.pos) - this.pos);
      ++this.pos;
      if (code > 0x10FFFF) { this.invalidStringToken(codePos, "Code point out of bounds"); }
    } else {
      code = this.readHexChar(4);
    }
    return code
  };
  
  function codePointToString(code) {
    // UTF-16 Decoding
    if (code <= 0xFFFF) { return String.fromCharCode(code) }
    code -= 0x10000;
    return String.fromCharCode((code >> 10) + 0xD800, (code & 1023) + 0xDC00)
  }
  
  pp$8.readString = function(quote) {
    var this$1 = this;
  
    var out = "", chunkStart = ++this.pos;
    for (;;) {
      if (this$1.pos >= this$1.input.length) { this$1.raise(this$1.start, "Unterminated string constant"); }
      var ch = this$1.input.charCodeAt(this$1.pos);
      if (ch === quote) { break }
      if (ch === 92) { // '\'
        out += this$1.input.slice(chunkStart, this$1.pos);
        out += this$1.readEscapedChar(false);
        chunkStart = this$1.pos;
      } else {
        if (isNewLine(ch)) { this$1.raise(this$1.start, "Unterminated string constant"); }
        ++this$1.pos;
      }
    }
    out += this.input.slice(chunkStart, this.pos++);
    return this.finishToken(types.string, out)
  };
  
  // Reads template string tokens.
  
  var INVALID_TEMPLATE_ESCAPE_ERROR = {};
  
  pp$8.tryReadTemplateToken = function() {
    this.inTemplateElement = true;
    try {
      this.readTmplToken();
    } catch (err) {
      if (err === INVALID_TEMPLATE_ESCAPE_ERROR) {
        this.readInvalidTemplateToken();
      } else {
        throw err
      }
    }
  
    this.inTemplateElement = false;
  };
  
  pp$8.invalidStringToken = function(position, message) {
    if (this.inTemplateElement && this.options.ecmaVersion >= 9) {
      throw INVALID_TEMPLATE_ESCAPE_ERROR
    } else {
      this.raise(position, message);
    }
  };
  
  pp$8.readTmplToken = function() {
    var this$1 = this;
  
    var out = "", chunkStart = this.pos;
    for (;;) {
      if (this$1.pos >= this$1.input.length) { this$1.raise(this$1.start, "Unterminated template"); }
      var ch = this$1.input.charCodeAt(this$1.pos);
      if (ch === 96 || ch === 36 && this$1.input.charCodeAt(this$1.pos + 1) === 123) { // '`', '${'
        if (this$1.pos === this$1.start && (this$1.type === types.template || this$1.type === types.invalidTemplate)) {
          if (ch === 36) {
            this$1.pos += 2;
            return this$1.finishToken(types.dollarBraceL)
          } else {
            ++this$1.pos;
            return this$1.finishToken(types.backQuote)
          }
        }
        out += this$1.input.slice(chunkStart, this$1.pos);
        return this$1.finishToken(types.template, out)
      }
      if (ch === 92) { // '\'
        out += this$1.input.slice(chunkStart, this$1.pos);
        out += this$1.readEscapedChar(true);
        chunkStart = this$1.pos;
      } else if (isNewLine(ch)) {
        out += this$1.input.slice(chunkStart, this$1.pos);
        ++this$1.pos;
        switch (ch) {
        case 13:
          if (this$1.input.charCodeAt(this$1.pos) === 10) { ++this$1.pos; }
        case 10:
          out += "\n";
          break
        default:
          out += String.fromCharCode(ch);
          break
        }
        if (this$1.options.locations) {
          ++this$1.curLine;
          this$1.lineStart = this$1.pos;
        }
        chunkStart = this$1.pos;
      } else {
        ++this$1.pos;
      }
    }
  };
  
  // Reads a template token to search for the end, without validating any escape sequences
  pp$8.readInvalidTemplateToken = function() {
    var this$1 = this;
  
    for (; this.pos < this.input.length; this.pos++) {
      switch (this$1.input[this$1.pos]) {
      case "\\":
        ++this$1.pos;
        break
  
      case "$":
        if (this$1.input[this$1.pos + 1] !== "{") {
          break
        }
      // falls through
  
      case "`":
        return this$1.finishToken(types.invalidTemplate, this$1.input.slice(this$1.start, this$1.pos))
  
      // no default
      }
    }
    this.raise(this.start, "Unterminated template");
  };
  
  // Used to read escaped characters
  
  pp$8.readEscapedChar = function(inTemplate) {
    var ch = this.input.charCodeAt(++this.pos);
    ++this.pos;
    switch (ch) {
    case 110: return "\n" // 'n' -> '\n'
    case 114: return "\r" // 'r' -> '\r'
    case 120: return String.fromCharCode(this.readHexChar(2)) // 'x'
    case 117: return codePointToString(this.readCodePoint()) // 'u'
    case 116: return "\t" // 't' -> '\t'
    case 98: return "\b" // 'b' -> '\b'
    case 118: return "\u000b" // 'v' -> '\u000b'
    case 102: return "\f" // 'f' -> '\f'
    case 13: if (this.input.charCodeAt(this.pos) === 10) { ++this.pos; } // '\r\n'
    case 10: // ' \n'
      if (this.options.locations) { this.lineStart = this.pos; ++this.curLine; }
      return ""
    default:
      if (ch >= 48 && ch <= 55) {
        var octalStr = this.input.substr(this.pos - 1, 3).match(/^[0-7]+/)[0];
        var octal = parseInt(octalStr, 8);
        if (octal > 255) {
          octalStr = octalStr.slice(0, -1);
          octal = parseInt(octalStr, 8);
        }
        if (octalStr !== "0" && (this.strict || inTemplate)) {
          this.invalidStringToken(this.pos - 2, "Octal literal in strict mode");
        }
        this.pos += octalStr.length - 1;
        return String.fromCharCode(octal)
      }
      return String.fromCharCode(ch)
    }
  };
  
  // Used to read character escape sequences ('\x', '\u', '\U').
  
  pp$8.readHexChar = function(len) {
    var codePos = this.pos;
    var n = this.readInt(16, len);
    if (n === null) { this.invalidStringToken(codePos, "Bad character escape sequence"); }
    return n
  };
  
  // Read an identifier, and return it as a string. Sets `this.containsEsc`
  // to whether the word contained a '\u' escape.
  //
  // Incrementally adds only escaped chars, adding other chunks as-is
  // as a micro-optimization.
  
  pp$8.readWord1 = function() {
    var this$1 = this;
  
    this.containsEsc = false;
    var word = "", first = true, chunkStart = this.pos;
    var astral = this.options.ecmaVersion >= 6;
    while (this.pos < this.input.length) {
      var ch = this$1.fullCharCodeAtPos();
      if (isIdentifierChar(ch, astral)) {
        this$1.pos += ch <= 0xffff ? 1 : 2;
      } else if (ch === 92) { // "\"
        this$1.containsEsc = true;
        word += this$1.input.slice(chunkStart, this$1.pos);
        var escStart = this$1.pos;
        if (this$1.input.charCodeAt(++this$1.pos) != 117) // "u"
          { this$1.invalidStringToken(this$1.pos, "Expecting Unicode escape sequence \\uXXXX"); }
        ++this$1.pos;
        var esc = this$1.readCodePoint();
        if (!(first ? isIdentifierStart : isIdentifierChar)(esc, astral))
          { this$1.invalidStringToken(escStart, "Invalid Unicode escape"); }
        word += codePointToString(esc);
        chunkStart = this$1.pos;
      } else {
        break
      }
      first = false;
    }
    return word + this.input.slice(chunkStart, this.pos)
  };
  
  // Read an identifier or keyword token. Will check for reserved
  // words when necessary.
  
  pp$8.readWord = function() {
    var word = this.readWord1();
    var type = types.name;
    if (this.keywords.test(word)) {
      if (this.containsEsc) { this.raiseRecoverable(this.start, "Escape sequence in keyword " + word); }
      type = keywords$1[word];
    }
    return this.finishToken(type, word)
  };
  
  // Acorn is a tiny, fast JavaScript parser written in JavaScript.
  //
  // Acorn was written by Marijn Haverbeke, Ingvar Stepanyan, and
  // various contributors and released under an MIT license.
  //
  // Git repositories for Acorn are available at
  //
  //     http://marijnhaverbeke.nl/git/acorn
  //     https://github.com/ternjs/acorn.git
  //
  // Please use the [github bug tracker][ghbt] to report issues.
  //
  // [ghbt]: https://github.com/ternjs/acorn/issues
  //
  // This file defines the main parser interface. The library also comes
  // with a [error-tolerant parser][dammit] and an
  // [abstract syntax tree walker][walk], defined in other files.
  //
  // [dammit]: acorn_loose.js
  // [walk]: util/walk.js
  
  var version = "5.2.1";
  
  // The main exported interface (under `self.acorn` when in the
  // browser) is a `parse` function that takes a code string and
  // returns an abstract syntax tree as specified by [Mozilla parser
  // API][api].
  //
  // [api]: https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API
  
  function parse(input, options) {
    return new Parser(options, input).parse()
  }
  
  // This function tries to parse a single expression at a given
  // offset in a string. Useful for parsing mixed-language formats
  // that embed JavaScript expressions.
  
  function parseExpressionAt(input, pos, options) {
    var p = new Parser(options, input, pos);
    p.nextToken();
    return p.parseExpression()
  }
  
  // Acorn is organized as a tokenizer and a recursive-descent parser.
  // The `tokenizer` export provides an interface to the tokenizer.
  
  function tokenizer(input, options) {
    return new Parser(options, input)
  }
  
  // This is a terrible kludge to support the existing, pre-ES6
  // interface where the loose parser module retroactively adds exports
  // to this module.
   // eslint-disable-line camelcase
  function addLooseExports(parse, Parser$$1, plugins$$1) {
    exports.parse_dammit = parse; // eslint-disable-line camelcase
    exports.LooseParser = Parser$$1;
    exports.pluginsLoose = plugins$$1;
  }
  
  exports.version = version;
  exports.parse = parse;
  exports.parseExpressionAt = parseExpressionAt;
  exports.tokenizer = tokenizer;
  exports.addLooseExports = addLooseExports;
  exports.Parser = Parser;
  exports.plugins = plugins;
  exports.defaultOptions = defaultOptions;
  exports.Position = Position;
  exports.SourceLocation = SourceLocation;
  exports.getLineInfo = getLineInfo;
  exports.Node = Node;
  exports.TokenType = TokenType;
  exports.tokTypes = types;
  exports.keywordTypes = keywords$1;
  exports.TokContext = TokContext;
  exports.tokContexts = types$1;
  exports.isIdentifierChar = isIdentifierChar;
  exports.isIdentifierStart = isIdentifierStart;
  exports.Token = Token;
  exports.isNewLine = isNewLine;
  exports.lineBreak = lineBreak;
  exports.lineBreakG = lineBreakG;
  exports.nonASCIIwhitespace = nonASCIIwhitespace;
  
  Object.defineProperty(exports, '__esModule', { value: true });
  
  })));