Remove Comprehension type in polymer expressions

Remove comprehension object, but return the list of scopes directly instead.

This is to fix https://code.google.com/p/dart/issues/detail?id=18792:
creating a new list of scopes on every invocation to _convertValue was causing us to issue extra notifications, which in turn caused the bug with <select> in that bug.

R=jmesserly@google.com, justinfagnani@google.com

Committed: https://code.google.com/p/dart/source/detail?r=36848

[Siggi Cherem (dart-lang), 2014-05-30 21:36:03]

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer/test/nested...
File pkg/polymer/test/nested_binding_test.dart (left):

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer/test/nested...
pkg/polymer/test/nested_binding_test.dart:27:
onMutation($['fruit']).then(_runTest);
with this change I'm seeing the mutation already in the page by the time ready
is called

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
File pkg/polymer_expressions/lib/polymer_expressions.dart (right):

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
pkg/polymer_expressions/lib/polymer_expressions.dart:127: _check(v, {bool
skipChanges: false}) {
this rename is not necessary, but it makes the code match closer what we do in
path_observer.dart. I'm happy to revert it if you prefer it like it was.

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
File pkg/polymer_expressions/test/bindings_test.dart (right):

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
pkg/polymer_expressions/test/bindings_test.dart:155: test('should preserve the
cursor position', () {
this test is unchanged, just moved down and changed indentation.

[Jennifer Messerly, 2014-05-30 22:55:09]

lgtm

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
File pkg/polymer_expressions/lib/eval.dart (left):

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
pkg/polymer_expressions/lib/eval.dart:733: // TODO: make Comprehension
observable and update it
does this TODO need to stick around?

[justinfagnani, 2014-05-30 22:58:32]

lgtm

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
File pkg/polymer_expressions/lib/polymer_expressions.dart (right):

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
pkg/polymer_expressions/lib/polymer_expressions.dart:127: _check(v, {bool
skipChanges: false}) {
On 2014/05/30 21:36:03, Siggi Cherem (dart-lang) wrote:
> this rename is not necessary, but it makes the code match closer what we do in
> path_observer.dart. I'm happy to revert it if you prefer it like it was.

Please make as few changes as possible, it makes my job rebasing the CL I have
outstanding much easier.

[Jennifer Messerly, 2014-05-30 23:00:56]

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
File pkg/polymer_expressions/lib/polymer_expressions.dart (right):

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
pkg/polymer_expressions/lib/polymer_expressions.dart:127: _check(v, {bool
skipChanges: false}) {
On 2014/05/30 22:58:33, justinfagnani wrote:
> On 2014/05/30 21:36:03, Siggi Cherem (dart-lang) wrote:
> > this rename is not necessary, but it makes the code match closer what we do
in
> > path_observer.dart. I'm happy to revert it if you prefer it like it was.
> 
> Please make as few changes as possible, it makes my job rebasing the CL I have
> outstanding much easier.

yeah, sorry about rebase difficulty.

But I just wanted to say Siggi: I really like these changes. Brining it more in
line with Rafael's observe-js style makes it much easier for me to read and
reason about. +1

[Siggi Cherem (dart-lang), 2014-05-30 23:25:11]

Committed patchset #1 manually as r36848 (presubmit successful).

[Siggi Cherem (dart-lang), 2014-05-31 00:56:17]

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
File pkg/polymer_expressions/lib/eval.dart (left):

https://codereview.chromium.org/304223004/diff/120001/pkg/polymer_expressions...
pkg/polymer_expressions/lib/eval.dart:733: // TODO: make Comprehension
observable and update it
On 2014/05/30 22:55:10, John Messerly wrote:
> does this TODO need to stick around?

Yes, but there was already an equivalent TODO in _LocalVariableScope, which is
where this would also be implemented :-)