es.string.split.js 4.7 KB

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  1. 'use strict';
  2. var call = require('../internals/function-call');
  3. var uncurryThis = require('../internals/function-uncurry-this');
  4. var fixRegExpWellKnownSymbolLogic = require('../internals/fix-regexp-well-known-symbol-logic');
  5. var anObject = require('../internals/an-object');
  6. var isObject = require('../internals/is-object');
  7. var requireObjectCoercible = require('../internals/require-object-coercible');
  8. var speciesConstructor = require('../internals/species-constructor');
  9. var advanceStringIndex = require('../internals/advance-string-index');
  10. var toLength = require('../internals/to-length');
  11. var toString = require('../internals/to-string');
  12. var getMethod = require('../internals/get-method');
  13. var getRegExpFlags = require('../internals/regexp-get-flags');
  14. var regExpExec = require('../internals/regexp-exec-abstract');
  15. var stickyHelpers = require('../internals/regexp-sticky-helpers');
  16. var fails = require('../internals/fails');
  17. var UNSUPPORTED_Y = stickyHelpers.UNSUPPORTED_Y;
  18. var MAX_UINT32 = 0xFFFFFFFF;
  19. var min = Math.min;
  20. var push = uncurryThis([].push);
  21. var stringSlice = uncurryThis(''.slice);
  22. var stringIndexOf = uncurryThis(''.indexOf);
  23. // Chrome 51 has a buggy "split" implementation when RegExp#exec !== nativeExec
  24. // Weex JS has frozen built-in prototypes, so use try / catch wrapper
  25. var SPLIT_WORKS_WITH_OVERWRITTEN_EXEC = !fails(function () {
  26. // eslint-disable-next-line regexp/no-empty-group -- required for testing
  27. var re = /(?:)/;
  28. var originalExec = re.exec;
  29. re.exec = function () { return originalExec.apply(this, arguments); };
  30. var result = 'ab'.split(re);
  31. return result.length !== 2 || result[0] !== 'a' || result[1] !== 'b';
  32. });
  33. var BUGGY = 'abbc'.split(/(b)*/)[1] === 'c' ||
  34. // eslint-disable-next-line regexp/no-empty-group -- required for testing
  35. 'test'.split(/(?:)/, -1).length !== 4 ||
  36. 'ab'.split(/(?:ab)*/).length !== 2 ||
  37. '.'.split(/(.?)(.?)/).length !== 4 ||
  38. // eslint-disable-next-line regexp/no-empty-capturing-group, regexp/no-empty-group -- required for testing
  39. '.'.split(/()()/).length > 1 ||
  40. ''.split(/.?/).length;
  41. // @@split logic
  42. fixRegExpWellKnownSymbolLogic('split', function (SPLIT, nativeSplit, maybeCallNative) {
  43. var internalSplit = '0'.split(undefined, 0).length ? function (separator, limit) {
  44. return separator === undefined && limit === 0 ? [] : call(nativeSplit, this, separator, limit);
  45. } : nativeSplit;
  46. return [
  47. // `String.prototype.split` method
  48. // https://tc39.es/ecma262/#sec-string.prototype.split
  49. function split(separator, limit) {
  50. var O = requireObjectCoercible(this);
  51. var splitter = isObject(separator) ? getMethod(separator, SPLIT) : undefined;
  52. return splitter
  53. ? call(splitter, separator, O, limit)
  54. : call(internalSplit, toString(O), separator, limit);
  55. },
  56. // `RegExp.prototype[@@split]` method
  57. // https://tc39.es/ecma262/#sec-regexp.prototype-@@split
  58. //
  59. // NOTE: This cannot be properly polyfilled in engines that don't support
  60. // the 'y' flag.
  61. function (string, limit) {
  62. var rx = anObject(this);
  63. var S = toString(string);
  64. if (!BUGGY) {
  65. var res = maybeCallNative(internalSplit, rx, S, limit, internalSplit !== nativeSplit);
  66. if (res.done) return res.value;
  67. }
  68. var C = speciesConstructor(rx, RegExp);
  69. var flags = toString(getRegExpFlags(rx));
  70. var unicodeMatching = !!~stringIndexOf(flags, 'u') || !!~stringIndexOf(flags, 'v');
  71. if (UNSUPPORTED_Y) {
  72. if (!~stringIndexOf(flags, 'g')) flags += 'g';
  73. } else if (!~stringIndexOf(flags, 'y')) flags += 'y';
  74. // ^(? + rx + ) is needed, in combination with some S slicing, to
  75. // simulate the 'y' flag.
  76. var splitter = new C(UNSUPPORTED_Y ? '^(?:' + rx.source + ')' : rx, flags);
  77. var lim = limit === undefined ? MAX_UINT32 : limit >>> 0;
  78. if (lim === 0) return [];
  79. if (S.length === 0) return regExpExec(splitter, S) === null ? [S] : [];
  80. var p = 0;
  81. var q = 0;
  82. var A = [];
  83. while (q < S.length) {
  84. splitter.lastIndex = UNSUPPORTED_Y ? 0 : q;
  85. var z = regExpExec(splitter, UNSUPPORTED_Y ? stringSlice(S, q) : S);
  86. var e;
  87. if (
  88. z === null ||
  89. (e = min(toLength(splitter.lastIndex + (UNSUPPORTED_Y ? q : 0)), S.length)) === p
  90. ) {
  91. q = advanceStringIndex(S, q, unicodeMatching);
  92. } else {
  93. push(A, stringSlice(S, p, q));
  94. if (A.length === lim) return A;
  95. for (var i = 1; i <= z.length - 1; i++) {
  96. push(A, z[i]);
  97. if (A.length === lim) return A;
  98. }
  99. q = p = e;
  100. }
  101. }
  102. push(A, stringSlice(S, p));
  103. return A;
  104. }
  105. ];
  106. }, BUGGY || !SPLIT_WORKS_WITH_OVERWRITTEN_EXEC, UNSUPPORTED_Y);