Implementing CustomElement's attributeChanged callback.

Implementing CustomElement's attributeChanged callback in dart2js.

BUG=
R=jmesserly@google.com

Committed: https://code.google.com/p/dart/source/detail?r=28168

[blois, 2013-09-30 21:45:04]

https://codereview.chromium.org/25325004/diff/9001/sdk/lib/_internal/lib/js_h...
File sdk/lib/_internal/lib/js_helper.dart (right):

https://codereview.chromium.org/25325004/diff/9001/sdk/lib/_internal/lib/js_h...
sdk/lib/_internal/lib/js_helper.dart:1533: r' return function($0, $1, $4, $5) {
'
Not sure about the variable naming here- the message above has a warning about
not clashing. What are the rules? Can I change $2 and $3?

[Jennifer Messerly, 2013-09-30 22:16:07]

LGTM. I'll let Stephen answer the other questions :)

[sra1, 2013-10-01 02:27:17]

https://codereview.chromium.org/25325004/diff/9001/sdk/lib/_internal/lib/js_h...
File sdk/lib/_internal/lib/js_helper.dart (right):

https://codereview.chromium.org/25325004/diff/9001/sdk/lib/_internal/lib/js_h...
sdk/lib/_internal/lib/js_helper.dart:1533: r' return function($0, $1, $4, $5) {
'
On 2013/09/30 21:45:04, blois wrote:
> Not sure about the variable naming here- the message above has a warning about
> not clashing. What are the rules? Can I change $2 and $3?

Actually, the original code is slightly broken.
The passing of arity would be broken if convertDartCLosureToJS was inlined and
simpler.

The rule is: bind all values to variables with an enclosing call, and do
whatever you like inside that.

This is just the equivalent of the macro-expansion of Lisp's LET form.


'(function(closure, arity, context, invoke) {'
'  return function(a1, a2, a3, a4) {'
'     return invoke(closure, context, arity, a1, a2, a3, a4);'
'  };'
'})(#,#,#,#)', closure, arity, JS_..., DART....);

[blois, 2013-10-01 16:45:42]

Much better- I was trying to understand why those horrible variable names.

[blois, 2013-10-02 15:58:05]

Committed patchset #4 manually as r28168 (presubmit successful).