null is an instance of Dynamic (fix issue 443).

null is an instance of Dynamic (fix issue 443).
Committed: https://code.google.com/p/dart/source/detail?r=1715

[hausner, 2011-11-21 19:33:36]

lgtm

[srdjan, 2011-11-21 19:37:08]

DBC

http://codereview.chromium.org/8592004/diff/1/runtime/vm/code_generator_ia32.cc
File runtime/vm/code_generator_ia32.cc (right):

http://codereview.chromium.org/8592004/diff/1/runtime/vm/code_generator_ia32....
runtime/vm/code_generator_ia32.cc:1409: // and Null type.
It may be simpler to explain this in positive formulation:
"A null type is only an instance of Object, Dynamic or Null type."
Can we ever see a Null type here?

The case for "null is Object" is handled above, isn't it? Maybe add a comment.

[regis, 2011-11-21 19:53:31]

Thanks for the feedback.

http://codereview.chromium.org/8592004/diff/1/runtime/vm/code_generator_ia32.cc
File runtime/vm/code_generator_ia32.cc (right):

http://codereview.chromium.org/8592004/diff/1/runtime/vm/code_generator_ia32....
runtime/vm/code_generator_ia32.cc:1409: // and Null type.
On 2011/11/21 19:37:08, srdjan wrote:
> It may be simpler to explain this in positive formulation:
> "A null type is only an instance of Object, Dynamic or Null type."
> Can we ever see a Null type here?
> 
> The case for "null is Object" is handled above, isn't it? Maybe add a comment.

I'll remove the mention of Null type, since it is only a VM internal type that
cannot be seen by the user.

The cases for "null is Object" and for "null is Dynamic" are only handled above
if the other type (Object or Dynamic) is instantiated.

I'll add a comment in my next cl.