Reviewers: Lasse Reichstein,
Description:
Simplify regexp test call when the regexp starts and ends with '.*'.
Please review this at http://codereview.chromium.org/2645002/show
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/
Affected files:
M src/regexp.js
Index: src/regexp.js
===================================================================
--- src/regexp.js (revision 4793)
+++ src/regexp.js (working copy)
@@ -257,6 +257,10 @@
}
+// One-element cache for the simplified test regexp.
+var regexp_key;
+var regexp_val;
+
// Section 15.10.6.3 doesn't actually make sense, but the intention seems
to be
// that test is defined in terms of String.prototype.exec. However, it
probably
// means the original value of String.prototype.exec, which is what
everybody
@@ -281,9 +285,7 @@
}
var lastIndex = this.lastIndex;
-
var cache = regExpCache;
-
if (%_ObjectEquals(cache.type, 'test') &&
%_ObjectEquals(cache.regExp, this) &&
%_ObjectEquals(cache.subject, string) &&
@@ -291,6 +293,26 @@
return cache.answer;
}
+ // Remove irrelevant '.*' around a test regexp. The expression
+ // checks whether this.source starts and ends with '.*' and that the
third
+ // char is not a '?' and that the third to last char is not a '\'.
+ if (%_StringCharCodeAt(this.source,0) == 46 && // '.'
+ %_StringCharCodeAt(this.source,1) == 42 && // '*'
+ %_StringCharCodeAt(this.source,2) != 63 && // '?'
+ %_StringCharCodeAt(this.source,this.source.length - 3) != 28 &&
// '\'
+ %_StringCharCodeAt(this.source,this.source.length - 2) == 46 &&
// '.'
+ %_StringCharCodeAt(this.source,this.source.length - 1) == 42) {
// '*'
+ if (!%_ObjectEquals(regexp_key, this)) {
+ regexp_key = this;
+ regexp_val = new $RegExp(this.source.substring(2,
+ this.source.length -
2),
+ (this.global ? 'g' : '')
+ + (this.ignoreCase ? 'i' : '')
+ + (this.multiline ? 'm' : ''));
+ }
+ if (!regexp_val.test(s)) return false;
+ }
+
var length = s.length;
var i = this.global ? TO_INTEGER(lastIndex) : 0;
@@ -299,7 +321,7 @@
cache.subject = s;
cache.lastIndex = i;
- if (i < 0 || i > s.length) {
+ if (i < 0 || i > length) {
this.lastIndex = 0;
cache.answer = false;
return false;
--
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