918075 - Iteration of GeneratorObject user made is broken

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[teramako]

User Agent: Mozilla/5.0 (Windows NT 5.1; rv:27.0) Gecko/20100101 Firefox/27.0 (Beta/Release)
Build ID: 20130918030202

Steps to reproduce:

function * gene() {
  for (var i = 0; i < 3; ++i) {
    yield i;
  }
}
for (var v of gene()) {
  console.log(v);
}



Actual results:

Each 'v' variables are logged:
[object Object]: { done: false, value: 0 }
[object Object]: { done: false, value: 1 }
[object Object]: { done: false, value: 2 }
[object Object]: { done: true,  value: undefined }

And finally, an exception is occurred: TypeError: generator has already finished.



Expected results:

Each 'v' variables are should be logged:
0
1
2

Comment 1

[Jeff Walden [:Waldo]]

Yeah, star_generator_next is just wrong about this.  Looks like our iteration protocol stuff, internally, still needs a bit of cleanup/work to account for next on a closed star generator.  (Might also be the case that the patchwork to fix this is in a bug but isn't landed yet; not sure offhand.)

Comment 2

[Jason Orendorff [:jorendorff]]

I believe star_generator_next is correct. But for-of is still using the old iteration protocol. for-of is getting the necessary upgrade in bug 907077.

In the current ES6 draft, Generator.prototype.next calls GeneratorResume, which throws a TypeError in step 5 if the [[GeneratorState]] is not either "suspendedStart" or "suspendedYield".

http://people.mozilla.org/~jorendorff/es6-draft.html#sec-25.4.3.2

Comment 3

[Andy Wingo [:wingo]]

As Jason says, this is fixed in bug 907077.

Comment 4

[teramako]

It seems fixed by bug 907077 .

Comment 5

[Jason Orendorff [:jorendorff]]

We know what fixed it, so -> RESO FIXED. Thanks teramako!