fix PathObserver to avoid try+catch

fix PathObserver to avoid try+catch
also fixes staticwarnings

R=sigmund@google.com

Committed: https://code.google.com/p/dart/source/detail?r=29498

[Siggi Cherem (dart-lang), 2013-10-29 21:48:38]

lgtm

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
File pkg/observe/lib/src/path_observer.dart (right):

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
pkg/observe/lib/src/path_observer.dart:210: if (_hasMethod(type, const
Symbol('[]'))) {
does the # grammar support `#[]`?

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
pkg/observe/lib/src/path_observer.dart:211: return
object[MirrorSystem.getName(property)];
interesting, this will let people use:
  $.id.foo

instead of 
  $['id'].foo

?

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
pkg/observe/lib/src/path_observer.dart:216: if (!_hasMethod(type,
#noSuchMethod)) rethrow;
given your earlier check with _canGetProperty, what is a scenario where this
condition is false? (i.e. aren't we always rethrowing now?)

[Jennifer Messerly, 2013-10-29 22:03:29]

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
File pkg/observe/lib/src/path_observer.dart (right):

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
pkg/observe/lib/src/path_observer.dart:210: if (_hasMethod(type, const
Symbol('[]'))) {
On 2013/10/29 21:48:38, Siggi Cherem (dart-lang) wrote:
> does the # grammar support `#[]`?

crazy. apparently yes. changed.

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
pkg/observe/lib/src/path_observer.dart:211: return
object[MirrorSystem.getName(property)];
On 2013/10/29 21:48:38, Siggi Cherem (dart-lang) wrote:
> interesting, this will let people use:
>   $.id.foo
> 
> instead of 
>   $['id'].foo
> 
> ?

yes. This has always been the case with PathObserver and the built-in
TemplateBinding syntax.

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
pkg/observe/lib/src/path_observer.dart:216: if (!_hasMethod(type,
#noSuchMethod)) rethrow;
On 2013/10/29 21:48:38, Siggi Cherem (dart-lang) wrote:
> given your earlier check with _canGetProperty, what is a scenario where this
> condition is false? (i.e. aren't we always rethrowing now?)

consider the following:
* the object has noSuchMethod
* _canGetProperty with true -- yes, it might have the property!
* getField calls noSuchMethod, which throws
* we do not want to rethrow this error. And we don't.

[Jennifer Messerly, 2013-10-29 22:10:32]

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
File pkg/observe/lib/src/path_observer.dart (right):

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
pkg/observe/lib/src/path_observer.dart:211: return
object[MirrorSystem.getName(property)];
On 2013/10/29 22:03:30, John Messerly wrote:
> On 2013/10/29 21:48:38, Siggi Cherem (dart-lang) wrote:
> > interesting, this will let people use:
> >   $.id.foo
> > 
> > instead of 
> >   $['id'].foo
> > 
> > ?
> 
> yes. This has always been the case with PathObserver and the built-in
> TemplateBinding syntax.

added a comment

https://codereview.chromium.org/51483002/diff/40001/pkg/observe/lib/src/path_...
pkg/observe/lib/src/path_observer.dart:216: if (!_hasMethod(type,
#noSuchMethod)) rethrow;
On 2013/10/29 22:03:30, John Messerly wrote:
> On 2013/10/29 21:48:38, Siggi Cherem (dart-lang) wrote:
> > given your earlier check with _canGetProperty, what is a scenario where this
> > condition is false? (i.e. aren't we always rethrowing now?)
> 
> consider the following:
> * the object has noSuchMethod
> * _canGetProperty with true -- yes, it might have the property!
> * getField calls noSuchMethod, which throws
> * we do not want to rethrow this error. And we don't.

renamed to _maybeHasGetter/_maybeHasSetter

[Jennifer Messerly, 2013-10-29 22:18:50]

Committed patchset #7 manually as r29498 (presubmit successful).