Support async getters.

Support async getters.

BUG=http://dartbug.com/22184
R=floitsch@google.com

Committed: https://code.google.com/p/dart/source/detail?r=43333

[Johnni Winther, 2015-01-30 09:49:34]

johnniwinther@google.com changed reviewers:
+ floitsch@google.com

[floitsch, 2015-01-30 10:48:13]

LGTM.

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
File pkg/compiler/lib/src/scanner/parser.dart (right):

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
pkg/compiler/lib/src/scanner/parser.dart:949: bool hasAsync = false;
So far this seems unused.

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
pkg/compiler/lib/src/scanner/parser.dart:953: if (identical(value, 'get')) {
Why is this "identical"?

(it was already there before, but it feels unnecessary and error-prone)

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
pkg/compiler/lib/src/scanner/parser.dart:958: token = token.next;
shouldn't you set the 'hasAsync' to true?

[Johnni Winther, 2015-01-30 12:14:25]

Committed patchset #2 (id:20001) manually as 43333 (presubmit successful).

[Johnni Winther, 2015-01-30 12:16:33]

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
File pkg/compiler/lib/src/scanner/parser.dart (right):

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
pkg/compiler/lib/src/scanner/parser.dart:949: bool hasAsync = false;
On 2015/01/30 10:48:13, floitsch wrote:
> So far this seems unused.

Removed.

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
pkg/compiler/lib/src/scanner/parser.dart:953: if (identical(value, 'get')) {
On 2015/01/30 10:48:13, floitsch wrote:
> Why is this "identical"?
> 
> (it was already there before, but it feels unnecessary and error-prone)

The pattern is from when identical on String was faster than ==. I guess that is
no longer the case.

Replaced all uses in this method.

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
pkg/compiler/lib/src/scanner/parser.dart:958: token = token.next;
On 2015/01/30 10:48:13, floitsch wrote:
> shouldn't you set the 'hasAsync' to true?

Wasn't needed after all.

[floitsch, 2015-01-30 12:18:14]

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
File pkg/compiler/lib/src/scanner/parser.dart (right):

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
pkg/compiler/lib/src/scanner/parser.dart:953: if (identical(value, 'get')) {
On 2015/01/30 12:16:33, Johnni Winther wrote:
> On 2015/01/30 10:48:13, floitsch wrote:
> > Why is this "identical"?
> > 
> > (it was already there before, but it feels unnecessary and error-prone)
> 
> The pattern is from when identical on String was faster than ==. I guess that
is
> no longer the case.
> 
> Replaced all uses in this method.

It might still be, but it feels error-prone to depend on the fact that the token
uses the literal "get" and not anything else.

[Johnni Winther, 2015-01-30 15:40:16]

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
File pkg/compiler/lib/src/scanner/parser.dart (right):

https://codereview.chromium.org/892583002/diff/1/pkg/compiler/lib/src/scanner...
pkg/compiler/lib/src/scanner/parser.dart:953: if (identical(value, 'get')) {
On 2015/01/30 12:18:14, floitsch wrote:
> On 2015/01/30 12:16:33, Johnni Winther wrote:
> > On 2015/01/30 10:48:13, floitsch wrote:
> > > Why is this "identical"?
> > > 
> > > (it was already there before, but it feels unnecessary and error-prone)
> > 
> > The pattern is from when identical on String was faster than ==. I guess
that
> is
> > no longer the case.
> > 
> > Replaced all uses in this method.
> 
> It might still be, but it feels error-prone to depend on the fact that the
token
> uses the literal "get" and not anything else.

According to http://dartbug.com/15514 the problem is resolved.

[ahe, 2016-04-25 12:54:14]

ahe@google.com changed reviewers:
+ ahe@google.com

[ahe, 2016-04-25 12:54:15]

DBC

https://codereview.chromium.org/892583002/diff/20001/pkg/compiler/lib/src/sca...
File pkg/compiler/lib/src/scanner/parser.dart (right):

https://codereview.chromium.org/892583002/diff/20001/pkg/compiler/lib/src/sca...
pkg/compiler/lib/src/scanner/parser.dart:954: (value == 'sync' || value ==
'async')) {
FWIW, for sake of performance, it's important that you use identical when
comparing keywords in the parser.

[Johnni Winther, 2016-04-25 13:36:02]

https://codereview.chromium.org/892583002/diff/20001/pkg/compiler/lib/src/sca...
File pkg/compiler/lib/src/scanner/parser.dart (right):

https://codereview.chromium.org/892583002/diff/20001/pkg/compiler/lib/src/sca...
pkg/compiler/lib/src/scanner/parser.dart:954: (value == 'sync' || value ==
'async')) {
On 2016/04/25 12:54:15, ahe wrote:
> FWIW, for sake of performance, it's important that you use identical when
> comparing keywords in the parser.

I was under the imprecision that the VM had optimized for this.

[ahe, 2016-04-25 13:39:53]

https://codereview.chromium.org/892583002/diff/20001/pkg/compiler/lib/src/sca...
File pkg/compiler/lib/src/scanner/parser.dart (right):

https://codereview.chromium.org/892583002/diff/20001/pkg/compiler/lib/src/sca...
pkg/compiler/lib/src/scanner/parser.dart:954: (value == 'sync' || value ==
'async')) {
On 2016/04/25 13:36:02, Johnni Winther wrote:
> On 2016/04/25 12:54:15, ahe wrote:
> > FWIW, for sake of performance, it's important that you use identical when
> > comparing keywords in the parser.
> 
> I was under the imprecision that the VM had optimized for this.

It's probably optimized with something like this:

operator ==(String s) {
  if (identical(this, s)) return true;
  // Normal "slow" case.
}

So we often end up in the slow case.