Fixes #151

Fixes #151

Type check async-return, async*-yield, and sync*-yield.

R=leafp@google.com

Committed: https://github.com/dart-lang/dev_compiler/commit/da59b9304a81cbbc636b13671a3083719274916e

[vsm, 2015-06-19 21:01:09]

vsm@google.com changed reviewers:
+ leafp@google.com

[Leaf, 2015-06-19 22:15:27]

I think this is missing support for yield*, but otherwise LGTM.  If you're just
not worrying about yield* yet, maybe a comment to that effect, and/or an
assertion that we're not in that case?

https://codereview.chromium.org/1190413005/diff/1/lib/src/checker/checker.dart
File lib/src/checker/checker.dart (right):

https://codereview.chromium.org/1190413005/diff/1/lib/src/checker/checker.dar...
lib/src/checker/checker.dart:656: _checkReturnOrYield(node.expression, node);
I think this will do the wrong thing if this yield statement is a yield*
statement.  For yield* e you want to check the type of e against the return
type, but I think this will fall into one of the generator cases above and
project out the type argument.

https://codereview.chromium.org/1190413005/diff/1/test/checker/checker_test.dart
File test/checker/checker_test.dart (right):

https://codereview.chromium.org/1190413005/diff/1/test/checker/checker_test.d...
test/checker/checker_test.dart:2701: Stream<int> bar4() async* { yield
(/*severe:StaticTypeError*/new Stream<int>()); }
Maybe test yield* as well?

[vsm, 2015-06-19 23:09:45]

yield*

[vsm, 2015-06-19 23:12:34]

Reformat

[vsm, 2015-06-19 23:15:25]

Added yield* - PTAL

https://codereview.chromium.org/1190413005/diff/40001/test/checker/checker_te...
File test/checker/checker_test.dart (right):

https://codereview.chromium.org/1190413005/diff/40001/test/checker/checker_te...
test/checker/checker_test.dart:2705: Stream<int> baz3() async* { yield*
(/*warning:DownCastComposite*/x); }
A bit odd that these are not DynamicCasts, but for now we're complaining a
little more loudly here.

[vsm, 2015-06-22 17:22:31]

Committed patchset #3 (id:40001) manually as
da59b9304a81cbbc636b13671a3083719274916e (presubmit successful).

[Leaf, 2015-06-23 01:19:28]

On 2015/06/22 17:22:31, vsm wrote:
> Committed patchset #3 (id:40001) manually as
> da59b9304a81cbbc636b13671a3083719274916e (presubmit successful).

still lgtm