implement tear offs

implement tear offs

R=jacobr@google.com

Committed: https://github.com/dart-lang/dev_compiler/commit/4138cbc6239fabd31ad892b4ebe51ab6799f7d3f

[Jennifer Messerly, 2015-04-21 18:49:59]

jmesserly@google.com changed reviewers:
+ jacobr@google.com

[Jacob, 2015-04-21 20:27:57]

https://codereview.chromium.org/1088943006/diff/1/lib/runtime/dart/convert.js
File lib/runtime/dart/convert.js (right):

https://codereview.chromium.org/1088943006/diff/1/lib/runtime/dart/convert.js...
lib/runtime/dart/convert.js:1579: return new
ClosableStringSink.fromStringSink(this[_stringSink], dart.bind(this, 'close'));
I don't get why this case is dart.bind(this, 'close') instead of
this.close.bind(this)

seems like "this" is stateless. what am I missing?

[Jennifer Messerly, 2015-04-21 21:11:06]

https://codereview.chromium.org/1088943006/diff/1/lib/runtime/dart/convert.js
File lib/runtime/dart/convert.js (right):

https://codereview.chromium.org/1088943006/diff/1/lib/runtime/dart/convert.js...
lib/runtime/dart/convert.js:1579: return new
ClosableStringSink.fromStringSink(this[_stringSink], dart.bind(this, 'close'));
On 2015/04/21 20:27:56, Jacob wrote:
> I don't get why this case is dart.bind(this, 'close') instead of
> this.close.bind(this)
> 
> seems like "this" is stateless. what am I missing?

Hmmm. The stateless checker may only work for identifiers (which `this` is not).
Well the good news, improving it here probably improves it everywhere that uses
isStateless :)

Does it look good other than this? It might be cleaner to fix in a follow up, in
case there are other diffs to baselines

[Jacob, 2015-04-21 21:15:46]

lgtm

[Jennifer Messerly, 2015-04-21 22:30:22]

Committed patchset #1 (id:1) manually as
4138cbc6239fabd31ad892b4ebe51ab6799f7d3f (presubmit successful).