Remapped regexp last-match-info to put subject and index before match indices.

src/regexp-delay.js

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // 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
@@ skipping 282 matching lines @@
 function RegExpGetRightContext() {
   var subject = LAST_SUBJECT(lastMatchInfo);
   return SubString(subject,
                    lastMatchInfo[CAPTURE1],
                    subject.length);
 }
 
 
 // The properties $1..$9 are the first nine capturing substrings of the last
 // successful match, or ''.  The function RegExpMakeCaptureGetter will be
-// called with indeces from 1 to 9.
+// called with indices from 1 to 9.
 function RegExpMakeCaptureGetter(n) {
   return function() {
     var index = n * 2;
     if (index >= NUMBER_OF_CAPTURES(lastMatchInfo)) return '';
     var matchStart = lastMatchInfo[CAPTURE(index)];
     var matchEnd = lastMatchInfo[CAPTURE(index + 1)];
     if (matchStart == -1 || matchEnd == -1) return '';
     return SubString(LAST_SUBJECT(lastMatchInfo), matchStart, matchEnd);
   };
 }
 
 
 // Property of the builtins object for recording the result of the last
 // regexp match.  The property lastMatchInfo includes the matchIndices
 // array of the last successful regexp match (an array of start/end index
 // pairs for the match and all the captured substrings), the invariant is
 // that there are at least two capture indeces.  The array also contains
 // the subject string for the last successful match.
 var lastMatchInfo = [
     2,                 // REGEXP_NUMBER_OF_CAPTURES
+    "",                // Last subject.
+    void 0,            // Last input - settable with RegExpSetInput.
     0,                 // REGEXP_FIRST_CAPTURE + 0
     0,                 // REGEXP_FIRST_CAPTURE + 1
-    "",                // Last subject.
-    void 0,            // Last input - settable with RegExpSetInput.
 ];
 
 // -------------------------------------------------------------------
 
 function SetupRegExp() {
   %FunctionSetInstanceClassName($RegExp, 'RegExp');
   %FunctionSetPrototype($RegExp, new $Object());
   %SetProperty($RegExp.prototype, 'constructor', $RegExp, DONT_ENUM);
   %SetCode($RegExp, RegExpConstructor);
 
   InstallFunctions($RegExp.prototype, DONT_ENUM, $Array(
     "exec", RegExpExec,
     "test", RegExpTest,
     "toString", RegExpToString,
     "compile", CompileRegExp
   ));
 
   // The length of compile is 1 in SpiderMonkey.
   %FunctionSetLength($RegExp.prototype.compile, 1);
 
   // The properties input, $input, and $_ are aliases for each other.  When this
   // value is set the value it is set to is coerced to a string. 
   // Getter and setter for the input.
   function RegExpGetInput() {
     var regExpInput = LAST_INPUT(lastMatchInfo);
     return IS_UNDEFINED(regExpInput) ? "" : regExpInput;
   }
   function RegExpSetInput(string) {
-    lastMatchInfo[lastMatchInfo[REGEXP_NUMBER_OF_CAPTURES] + 2] =
-        ToString(string);
+    LAST_INPUT(lastMatchInfo) = ToString(string);

[Erik Corry, 2009/03/17 12:39:32]

This is much prettier, thanks!

   };
 
   // All these accessors are set with the 'never_used' flag set to true.
   // This is because at this point there can be no existing ics for setting
   // these properties and so we don't have to bother clearing them.
   %DefineAccessor($RegExp, 'input', GETTER, RegExpGetInput, DONT_DELETE);
   %DefineAccessor($RegExp, 'input', SETTER, RegExpSetInput, DONT_DELETE, true);
   %DefineAccessor($RegExp, '$_', GETTER, RegExpGetInput, DONT_ENUM | DONT_DELETE);
   %DefineAccessor($RegExp, '$_', SETTER, RegExpSetInput, DONT_ENUM | DONT_DELETE, true);
   %DefineAccessor($RegExp, '$input', GETTER, RegExpGetInput, DONT_ENUM | DONT_DELETE);
@@ skipping 39 matching lines @@
   %DefineAccessor($RegExp, "$'", SETTER, NoOpSetter, DONT_ENUM | DONT_DELETE, true);
 
   for (var i = 1; i < 10; ++i) {
     %DefineAccessor($RegExp, '$' + i, GETTER, RegExpMakeCaptureGetter(i), DONT_DELETE);
     %DefineAccessor($RegExp, '$' + i, SETTER, NoOpSetter, DONT_DELETE, true);
   }
 }
 
 
 SetupRegExp();