Split up String.split to deal with normal separator and regexp separator separately.

src/string.js

 // Copyright 2006-2009 the V8 project authors. All rights reserved.

[Jakob Kummerow, 2012/03/13 15:39:06]

2012

 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
@@ skipping 573 matching lines @@
   }
   var subject = TO_STRING_INLINE(this);
   limit = (IS_UNDEFINED(limit)) ? 0xffffffff : TO_UINT32(limit);
 
   // ECMA-262 says that if separator is undefined, the result should
   // be an array of size 1 containing the entire string.
   if (IS_UNDEFINED(separator)) {
     return [subject];
   }
 
+  if (limit === 0) return [];
+
   var length = subject.length;
   if (!IS_REGEXP(separator)) {
     separator = TO_STRING_INLINE(separator);
 
-    if (limit === 0) return [];
-
     var separator_length = separator.length;
 
     // If the separator string is empty then return the elements in the subject.
     if (separator_length === 0) return %StringToArray(subject, limit);
 
     var result = %StringSplit(subject, separator, limit);
 
     return result;
   }
 
-  if (limit === 0) return [];
+  // Separator is a regular expression.
+  return StringSplitOnRegExp(subject, separator, limit, length);
+}
 
+
+function StringSplitOnRegExp(subject, separator, limit, length) {
   %_Log('regexp', 'regexp-split,%0S,%1r', [subject, separator]);
 
   if (length === 0) {
     if (DoRegExpExec(separator, subject, 0, 0) != null) {
       return [];
     }
     return [subject];
   }
 
   var currentIndex = 0;
@@ skipping 381 matching lines @@
     "fixed", StringFixed,
     "italics", StringItalics,
     "small", StringSmall,
     "strike", StringStrike,
     "sub", StringSub,
     "sup", StringSup
   ));
 }
 
 SetUpString();