[regexp] Port split

src/js/regexp.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(global, utils) {
 
 'use strict';
 
 %CheckIsBootstrapping();
 
@@ skipping 104 matching lines @@
     if (!IS_RECEIVER(result) && !IS_NULL(result)) {
       throw %make_type_error(kInvalidRegExpExecResult);
     }
     return result;
   }
   return %_Call(RegExpExecJS, regexp, string);
 }
 %SetForceInlineFlag(RegExpSubclassExec);
 
 
-function AtSurrogatePair(subject, index) {
-  if (index + 1 >= subject.length) return false;
-  var first = %_StringCharCodeAt(subject, index);
-  if (first < 0xD800 || first > 0xDBFF) return false;
-  var second = %_StringCharCodeAt(subject, index + 1);
-  return second >= 0xDC00 && second <= 0xDFFF;
-}
-
-
-// Fast path implementation of RegExp.prototype[Symbol.split] which
-// doesn't properly call the underlying exec, @@species methods
-function RegExpSplit(string, limit) {
-  if (!IS_REGEXP(this)) {
-    throw %make_type_error(kIncompatibleMethodReceiver,
-                        "RegExp.prototype.@@split", this);
-  }
-  var separator = this;
-  var subject = TO_STRING(string);
-
-  limit = (IS_UNDEFINED(limit)) ? kMaxUint32 : TO_UINT32(limit);
-  var length = subject.length;
-
-  if (limit === 0) return [];
-
-  if (length === 0) {
-    if (DoRegExpExec(separator, subject, 0, 0) !== null) return [];
-    return [subject];
-  }
-
-  var currentIndex = 0;
-  var startIndex = 0;
-  var startMatch = 0;
-  var result = new InternalArray();
-
-  outer_loop:
-  while (true) {
-    if (startIndex === length) {
-      result[result.length] = %_SubString(subject, currentIndex, length);
-      break;
-    }
-
-    var matchInfo = DoRegExpExec(separator, subject, startIndex);
-    if (matchInfo === null || length === (startMatch = matchInfo[CAPTURE0])) {
-      result[result.length] = %_SubString(subject, currentIndex, length);
-      break;
-    }
-    var endIndex = matchInfo[CAPTURE1];
-
-    // We ignore a zero-length match at the currentIndex.
-    if (startIndex === endIndex && endIndex === currentIndex) {
-      if (REGEXP_UNICODE(this) && AtSurrogatePair(subject, startIndex)) {
-        startIndex += 2;
-      } else {
-        startIndex++;
-      }
-      continue;
-    }
-
-    result[result.length] = %_SubString(subject, currentIndex, startMatch);
-
-    if (result.length === limit) break;
-
-    var matchinfo_len = NUMBER_OF_CAPTURES(matchInfo) + REGEXP_FIRST_CAPTURE;
-    for (var i = REGEXP_FIRST_CAPTURE + 2; i < matchinfo_len; ) {
-      var start = matchInfo[i++];
-      var end = matchInfo[i++];
-      if (end != -1) {
-        result[result.length] = %_SubString(subject, start, end);
-      } else {
-        result[result.length] = UNDEFINED;
-      }
-      if (result.length === limit) break outer_loop;
-    }
-
-    startIndex = currentIndex = endIndex;
-  }
-
-  var array_result = [];
-  %MoveArrayContents(result, array_result);
-  return array_result;
-}
-
-
-// ES#sec-regexp.prototype-@@split
-// RegExp.prototype [ @@split ] ( string, limit )
-function RegExpSubclassSplit(string, limit) {
-  if (!IS_RECEIVER(this)) {
-    throw %make_type_error(kIncompatibleMethodReceiver,
-                        "RegExp.prototype.@@split", this);
-  }
-  string = TO_STRING(string);
-  var constructor = SpeciesConstructor(this, GlobalRegExp);
-  var flags = TO_STRING(this.flags);
-
-  // TODO(adamk): this fast path is wrong as we doesn't ensure that 'exec'
-  // is actually a data property on RegExp.prototype.
-  if (IS_REGEXP(this) && constructor === GlobalRegExp) {
-    var exec = this.exec;
-    if (exec === RegExpExecJS) {
-      return %_Call(RegExpSplit, this, string, limit);
-    }
-  }
-
-  var unicode = %StringIndexOf(flags, 'u', 0) >= 0;
-  var sticky = %StringIndexOf(flags, 'y', 0) >= 0;
-  var newFlags = sticky ? flags : flags + "y";
-  var splitter = new constructor(this, newFlags);
-  var array = new GlobalArray();
-  var arrayIndex = 0;
-  var lim = (IS_UNDEFINED(limit)) ? kMaxUint32 : TO_UINT32(limit);
-  var size = string.length;
-  var prevStringIndex = 0;
-  if (lim === 0) return array;
-  var result;
-  if (size === 0) {
-    result = RegExpSubclassExec(splitter, string);
-    if (IS_NULL(result)) %AddElement(array, 0, string);
-    return array;
-  }
-  var stringIndex = prevStringIndex;
-  while (stringIndex < size) {
-    splitter.lastIndex = stringIndex;
-    result = RegExpSubclassExec(splitter, string);
-    if (IS_NULL(result)) {
-      stringIndex += AdvanceStringIndex(string, stringIndex, unicode);
-    } else {
-      var end = MinSimple(TO_LENGTH(splitter.lastIndex), size);
-      if (end === prevStringIndex) {
-        stringIndex += AdvanceStringIndex(string, stringIndex, unicode);
-      } else {
-        %AddElement(
-            array, arrayIndex,
-            %_SubString(string, prevStringIndex, stringIndex));
-        arrayIndex++;
-        if (arrayIndex === lim) return array;
-        prevStringIndex = end;
-        var numberOfCaptures = MaxSimple(TO_LENGTH(result.length), 0);
-        for (var i = 1; i < numberOfCaptures; i++) {
-          %AddElement(array, arrayIndex, result[i]);
-          arrayIndex++;
-          if (arrayIndex === lim) return array;
-        }
-        stringIndex = prevStringIndex;
-      }
-    }
-  }
-  %AddElement(array, arrayIndex,
-                     %_SubString(string, prevStringIndex, size));
-  return array;
-}
-%FunctionRemovePrototype(RegExpSubclassSplit);
-
-
 // Legacy implementation of RegExp.prototype[Symbol.replace] which
 // doesn't properly call the underlying exec method.
 
 // TODO(lrn): This array will survive indefinitely if replace is never
 // called again. However, it will be empty, since the contents are cleared
 // in the finally block.
 var reusableReplaceArray = new InternalArray(4);
 
 // Helper function for replacing regular expressions with the result of a
 // function application in String.prototype.replace.
@@ skipping 379 matching lines @@
   return accumulatedResult + %_SubString(string, nextSourcePosition, length);
 }
 %FunctionRemovePrototype(RegExpSubclassReplace);
 
 
 
 // -------------------------------------------------------------------
 
 utils.InstallFunctions(GlobalRegExp.prototype, DONT_ENUM, [
   replaceSymbol, RegExpSubclassReplace,
-  splitSymbol, RegExpSubclassSplit,
 ]);
 
 %InstallToContext(["regexp_last_match_info", RegExpLastMatchInfo]);
 
 // -------------------------------------------------------------------
 // Internal
 
 var InternalRegExpMatchInfo = {
   REGEXP_NUMBER_OF_CAPTURES: 2,
   REGEXP_LAST_SUBJECT:       "",
@@ skipping 22 matching lines @@
   to.GetSubstitution = GetSubstitution;
   to.InternalRegExpMatch = InternalRegExpMatch;
   to.InternalRegExpReplace = InternalRegExpReplace;
   to.IsRegExp = IsRegExp;
   to.RegExpExec = DoRegExpExec;
   to.RegExpInitialize = RegExpInitialize;
   to.RegExpLastMatchInfo = RegExpLastMatchInfo;
 });
 
 })