Fix unparse for empty initializer or conditionStatement.

Fix unparse for empty initializer or conditionStatement.

R=ahe@google.com,smok@google.com

Committed: https://code.google.com/p/dart/source/detail?r=8665

[Anton Muhin, 2012-06-07 15:31:29]

https://chromiumcodereview.appspot.com/10543051/diff/1/lib/compiler/implement...
File lib/compiler/implementation/tree/unparser.dart (right):

https://chromiumcodereview.appspot.com/10543051/diff/1/lib/compiler/implement...
lib/compiler/implementation/tree/unparser.dart:79: visitPart(part) {
another option would be to yield empty statements out of parser for those.

[Anton Muhin, 2012-06-07 15:40:21]

https://chromiumcodereview.appspot.com/10543051/diff/7001/lib/compiler/implem...
File lib/compiler/implementation/tree/unparser.dart (right):

https://chromiumcodereview.appspot.com/10543051/diff/7001/lib/compiler/implem...
lib/compiler/implementation/tree/unparser.dart:80: if (node.initializer is
!Statement) sb.add(';');
I think it's the best variant.

node.initializer can be null, a simple expression (x = 1) or a statement.  That
covers all the cases.  We still may prefer to make EmptyStatement instead of
null for 'for(;...)', but that's a separate issue.

[ahe, 2012-06-08 07:35:03]

I'm having a hard time understanding these fixes without seeing what is failing.

Could you add an unparser unit test to frog/tests/leg? Then I think the changes
would be easier to understand because I can see the test cases.

[ahe, 2012-06-14 15:14:50]

LGTM