Make sure we use lexical scope consistently when dealing with prefixes.

Make sure we use lexical scope consistently when dealing with prefixes.

BUG=
R=lrn@google.com, paulberry@google.com

Committed: https://github.com/dart-lang/sdk/commit/67b99e4b33023ecf162148fb8400da8839d73065

[gbracha, 2015-06-11 22:58:17]

gbracha@google.com changed reviewers:
+ hausner@google.com, lrn@google.com, paulberry@google.com

[gbracha, 2015-06-11 22:58:17]

Per discussion with Lars, we want to make the handling of prefixes consistent.
It may be a while before we actually choose to implement this, depending on how
much of a concern we have over compatibility. But this should go into the spec
so we can get it past TC52 in the upcoming iteration.

[Paul Berry, 2015-06-11 23:33:19]

lgtm.

Regarding when to implement this, my inclination would be to do the analyzer
implementation ASAP so we can try to get it into the first dev release for 1.12
at the end of June.  That way any users who are unfortunate enough to be relying
on our current inconsistency will be given as much notice as possible in the
form of an analyzer error, but their code won't break yet.  The Dart2js and VM
implementations can wait until a later release if we want to give people more
time to fix their code.

Does that sound reasonable?

[Lasse Reichstein Nielsen, 2015-06-12 07:17:01]

LGTM.

The only thing users could currently be doing wrong is having a setter with the
same name as the prefix, right? 
And that already doesn't work in dart2js, so I don't think we'll have much
breakage if we change it.

[Paul Berry, 2015-06-12 14:10:36]

On 2015/06/12 07:17:01, Lasse Reichstein Nielsen wrote:
> LGTM.
> 
> The only thing users could currently be doing wrong is having a setter with
the
> same name as the prefix, right? 
> And that already doesn't work in dart2js, so I don't think we'll have much
> breakage if we change it.

It's actually not just setters.  Currently the VM translates *all* references to
a prefix that aren't followed by "." into "this.prefix"
(https://github.com/dart-lang/sdk/issues/23612).  AFAICT, dart2js translates all
references to a prefix that aren't followed by "." into something that either
throws a runtime error or crashes the compiler.  So people who are using dart2js
won't be broken by the change, but people who have only been using the
standalone VM and/or Dartium might.

But in any case I agree with you that this particular spec change is unlikely to
cause much breakage.

[gbracha, 2015-06-13 00:38:47]

Committed patchset #1 (id:1) manually as
67b99e4b33023ecf162148fb8400da8839d73065 (presubmit successful).