Ensure UnionTypeMask.operator== works in the presence of nullability.

Ensure UnionTypeMask.operator== works in the presence of nullability.

R=kasperl@google.com

Committed: https://code.google.com/p/dart/source/detail?r=27173

[kasperl, 2013-09-05 06:40:56]

LGTM.

https://codereview.chromium.org/23672022/diff/3001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/types/union_type_mask.dart
(right):

https://codereview.chromium.org/23672022/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/types/union_type_mask.dart:270: var
map = disjointMasks.map((e) => e.nonNullable());
Freaky indentation. Maybe it would be simpler to understand if you did:

   other.disjointMasks
     .map((e) => e.nonNullable())
     .every((e) => disjointMasks.contains(e.nonNullable())

https://codereview.chromium.org/23672022/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/types/union_type_mask.dart:276: int
hashCode = 43;
Shouldn't the hashCode take the nullability of this into account?

https://codereview.chromium.org/23672022/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/types/union_type_mask.dart:278:
hashCode = (hashCode ^ mask.nonNullable().hashCode) & 0x3fffffff;
Add a comment that explains that it is important that the order of the masks in
the disjointMasks list doesn't affect the hash code?

[ngeoffray, 2013-09-05 06:53:18]

Thanks Kasper.

https://codereview.chromium.org/23672022/diff/3001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/types/union_type_mask.dart
(right):

https://codereview.chromium.org/23672022/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/types/union_type_mask.dart:270: var
map = disjointMasks.map((e) => e.nonNullable());
On 2013/09/05 06:40:56, kasperl wrote:
> Freaky indentation. Maybe it would be simpler to understand if you did:
> 
>    other.disjointMasks
>      .map((e) => e.nonNullable())
>      .every((e) => disjointMasks.contains(e.nonNullable())

Unfortunately I also need to map disjointMasks to an iterable non-nullable
types. I added a helper method to get rid of the weird indentation.

https://codereview.chromium.org/23672022/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/types/union_type_mask.dart:276: int
hashCode = 43;
On 2013/09/05 06:40:56, kasperl wrote:
> Shouldn't the hashCode take the nullability of this into account?

Done.

https://codereview.chromium.org/23672022/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/types/union_type_mask.dart:278:
hashCode = (hashCode ^ mask.nonNullable().hashCode) & 0x3fffffff;
On 2013/09/05 06:40:56, kasperl wrote:
> Add a comment that explains that it is important that the order of the masks
in
> the disjointMasks list doesn't affect the hash code?

Done.

[ngeoffray, 2013-09-05 07:01:16]

Committed patchset #2 manually as r27173 (presubmit successful).