1'use strict';
2
3var isRegExp = require('./_is-regexp');
4var anObject = require('./_an-object');
5var speciesConstructor = require('./_species-constructor');
6var advanceStringIndex = require('./_advance-string-index');
7var toLength = require('./_to-length');
8var callRegExpExec = require('./_regexp-exec-abstract');
9var regexpExec = require('./_regexp-exec');
10var fails = require('./_fails');
11var $min = Math.min;
12var $push = [].push;
13var $SPLIT = 'split';
14var LENGTH = 'length';
15var LAST_INDEX = 'lastIndex';
16var MAX_UINT32 = 0xffffffff;
17
18// babel-minify transpiles RegExp('x', 'y') -> /x/y and it causes SyntaxError
19var SUPPORTS_Y = !fails(function () { RegExp(MAX_UINT32, 'y'); });
20
21// @@split logic
22require('./_fix-re-wks')('split', 2, function (defined, SPLIT, $split, maybeCallNative) {
23  var internalSplit;
24  if (
25    'abbc'[$SPLIT](/(b)*/)[1] == 'c' ||
26    'test'[$SPLIT](/(?:)/, -1)[LENGTH] != 4 ||
27    'ab'[$SPLIT](/(?:ab)*/)[LENGTH] != 2 ||
28    '.'[$SPLIT](/(.?)(.?)/)[LENGTH] != 4 ||
29    '.'[$SPLIT](/()()/)[LENGTH] > 1 ||
30    ''[$SPLIT](/.?/)[LENGTH]
31  ) {
32    // based on es5-shim implementation, need to rework it
33    internalSplit = function (separator, limit) {
34      var string = String(this);
35      if (separator === undefined && limit === 0) return [];
36      // If `separator` is not a regex, use native split
37      if (!isRegExp(separator)) return $split.call(string, separator, limit);
38      var output = [];
39      var flags = (separator.ignoreCase ? 'i' : '') +
40                  (separator.multiline ? 'm' : '') +
41                  (separator.unicode ? 'u' : '') +
42                  (separator.sticky ? 'y' : '');
43      var lastLastIndex = 0;
44      var splitLimit = limit === undefined ? MAX_UINT32 : limit >>> 0;
45      // Make `global` and avoid `lastIndex` issues by working with a copy
46      var separatorCopy = new RegExp(separator.source, flags + 'g');
47      var match, lastIndex, lastLength;
48      while (match = regexpExec.call(separatorCopy, string)) {
49        lastIndex = separatorCopy[LAST_INDEX];
50        if (lastIndex > lastLastIndex) {
51          output.push(string.slice(lastLastIndex, match.index));
52          if (match[LENGTH] > 1 && match.index < string[LENGTH]) $push.apply(output, match.slice(1));
53          lastLength = match[0][LENGTH];
54          lastLastIndex = lastIndex;
55          if (output[LENGTH] >= splitLimit) break;
56        }
57        if (separatorCopy[LAST_INDEX] === match.index) separatorCopy[LAST_INDEX]++; // Avoid an infinite loop
58      }
59      if (lastLastIndex === string[LENGTH]) {
60        if (lastLength || !separatorCopy.test('')) output.push('');
61      } else output.push(string.slice(lastLastIndex));
62      return output[LENGTH] > splitLimit ? output.slice(0, splitLimit) : output;
63    };
64  // Chakra, V8
65  } else if ('0'[$SPLIT](undefined, 0)[LENGTH]) {
66    internalSplit = function (separator, limit) {
67      return separator === undefined && limit === 0 ? [] : $split.call(this, separator, limit);
68    };
69  } else {
70    internalSplit = $split;
71  }
72
73  return [
74    // `String.prototype.split` method
75    // https://tc39.github.io/ecma262/#sec-string.prototype.split
76    function split(separator, limit) {
77      var O = defined(this);
78      var splitter = separator == undefined ? undefined : separator[SPLIT];
79      return splitter !== undefined
80        ? splitter.call(separator, O, limit)
81        : internalSplit.call(String(O), separator, limit);
82    },
83    // `RegExp.prototype[@@split]` method
84    // https://tc39.github.io/ecma262/#sec-regexp.prototype-@@split
85    //
86    // NOTE: This cannot be properly polyfilled in engines that don't support
87    // the 'y' flag.
88    function (regexp, limit) {
89      var res = maybeCallNative(internalSplit, regexp, this, limit, internalSplit !== $split);
90      if (res.done) return res.value;
91
92      var rx = anObject(regexp);
93      var S = String(this);
94      var C = speciesConstructor(rx, RegExp);
95
96      var unicodeMatching = rx.unicode;
97      var flags = (rx.ignoreCase ? 'i' : '') +
98                  (rx.multiline ? 'm' : '') +
99                  (rx.unicode ? 'u' : '') +
100                  (SUPPORTS_Y ? 'y' : 'g');
101
102      // ^(? + rx + ) is needed, in combination with some S slicing, to
103      // simulate the 'y' flag.
104      var splitter = new C(SUPPORTS_Y ? rx : '^(?:' + rx.source + ')', flags);
105      var lim = limit === undefined ? MAX_UINT32 : limit >>> 0;
106      if (lim === 0) return [];
107      if (S.length === 0) return callRegExpExec(splitter, S) === null ? [S] : [];
108      var p = 0;
109      var q = 0;
110      var A = [];
111      while (q < S.length) {
112        splitter.lastIndex = SUPPORTS_Y ? q : 0;
113        var z = callRegExpExec(splitter, SUPPORTS_Y ? S : S.slice(q));
114        var e;
115        if (
116          z === null ||
117          (e = $min(toLength(splitter.lastIndex + (SUPPORTS_Y ? 0 : q)), S.length)) === p
118        ) {
119          q = advanceStringIndex(S, q, unicodeMatching);
120        } else {
121          A.push(S.slice(p, q));
122          if (A.length === lim) return A;
123          for (var i = 1; i <= z.length - 1; i++) {
124            A.push(z[i]);
125            if (A.length === lim) return A;
126          }
127          q = p = e;
128        }
129      }
130      A.push(S.slice(p));
131      return A;
132    }
133  ];
134});
135