Fwd: [JS-internals] additional test for 15.10.6.2, RegExp.prototype.exec

[Paul Ruizendaal]

 From: Brendan Eich bren...@mozilla.com
 Subject: Re: [JS-internals] additional test for 15.10.6.2, 
 RegExp.prototype.exec
 Date: 27 June 2013 0:16:49 GMT+02:00
 To: Paul Ruizendaal p...@planet.nl
 
 Please resend to es-discuss. At least two browsers agree on each side of the 
 fence, so this isn't just a mozilla.dev.tech.js-engine.internal issue.
 
 /be
 
 Paul Ruizendaal wrote:
 The Spidermonkey test suite contains the following test (in file 
 ecma_5/RegExp/exec.js):
 
 r = /abc/;
 r.lastIndex = -17;
 res = r.exec(cdefg);
 assertEq(res, null);
 assertEq(r.lastIndex, -17);
 
 In my understanding this test is wrong, lastIndex should be 0 due to step 
 9.a.(i). Safari and Firefox report -17, Chrome and IE report 0. I guess it 
 is a tricky part of the spec as most real world implementations will move 
 the iteration of step 9 into the [[Match]] routine as to enable first 
 character optimizations and alike. The correct behavior is not covered in 
 test262. Recommend to add the following test:
 
 /*
  * @es5id 15.10.6.2 (step 9.a.i)
  * @description If the pattern does not match, lastIndex is always set to 0, 
 even if the 'global' flag is false.
  */
 function testCase()
 {
   var r = /abc/;
   r.lastIndex = -17;
   res = r.exec(defg);
   return r.lastIndex===0;
 }
 
 Note that the original Spidermonkey test is in the public domain, according 
 to the file header. This post is also placed in the public domain.
 
 Paul
 
 ___
 dev-tech-js-engine-internals mailing list
 dev-tech-js-engine-intern...@lists.mozilla.org
 https://lists.mozilla.org/listinfo/dev-tech-js-engine-internals

___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss

Re: [JS-internals] additional test for 15.10.6.2, RegExp.prototype.exec

[Till Schneidereit]

Note that we have a bug[1] open and a patch in review for that now. As of
now, it looks like a bug we're going to fix, but Jeff might come to a
different conclusion during the review.


[1]: https://bugzilla.mozilla.org/show_bug.cgi?id=887676


On Fri, Jun 28, 2013 at 1:23 PM, Paul Ruizendaal p...@planet.nl wrote:


  From: Brendan Eich bren...@mozilla.com
  Subject: Re: [JS-internals] additional test for 15.10.6.2,
 RegExp.prototype.exec
  Date: 27 June 2013 0:16:49 GMT+02:00
  To: Paul Ruizendaal p...@planet.nl
 
  Please resend to es-discuss. At least two browsers agree on each side of
 the fence, so this isn't just a mozilla.dev.tech.js-engine.internal issue.
 
  /be
 
  Paul Ruizendaal wrote:
  The Spidermonkey test suite contains the following test (in file
 ecma_5/RegExp/exec.js):
 
  r = /abc/;
  r.lastIndex = -17;
  res = r.exec(cdefg);
  assertEq(res, null);
  assertEq(r.lastIndex, -17);
 
  In my understanding this test is wrong, lastIndex should be 0 due to
 step 9.a.(i). Safari and Firefox report -17, Chrome and IE report 0. I
 guess it is a tricky part of the spec as most real world implementations
 will move the iteration of step 9 into the [[Match]] routine as to enable
 first character optimizations and alike. The correct behavior is not
 covered in test262. Recommend to add the following test:
 
  /*
   * @es5id 15.10.6.2 (step 9.a.i)
   * @description If the pattern does not match, lastIndex is always set
 to 0, even if the 'global' flag is false.
   */
  function testCase()
  {
var r = /abc/;
r.lastIndex = -17;
res = r.exec(defg);
return r.lastIndex===0;
  }
 
  Note that the original Spidermonkey test is in the public domain,
 according to the file header. This post is also placed in the public domain.
 
  Paul
 
  ___
  dev-tech-js-engine-internals mailing list
  dev-tech-js-engine-intern...@lists.mozilla.org
  https://lists.mozilla.org/listinfo/dev-tech-js-engine-internals

 ___
 es-discuss mailing list
 es-discuss@mozilla.org
 https://mail.mozilla.org/listinfo/es-discuss

___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss