commit dbd9f2d59b393a3244308506e6e233d5d584be95
author Kallen Tu <kallentu@google.com> Tue Oct 15 19:12:31 2024 +0000
committer dart-internal-monorepo <dart-internal-monorepo@dart-ci-internal.iam.gserviceaccount.com> Tue Oct 15 12:17:02 2024 -0700
tree 5e140baff2b51618642b7fe4237ec2df5cc56b6b
parent b29a352a46d0d4ad5b6550bceaae08f2c88f5fa6

Enable 'wildcard-variables' feature flag.

This CL enables the wildcard variables feature by default in Dart 3.7.

Local variables and parameters named `_` are now non-binding and they can be declared multiple times without collisions. All wildcard variable declaration types that have this behavior are described in the
wildcard variables specification: https://github.com/dart-lang/language/blob/main/accepted/future-releases/wildcard-variables/feature-specification.md.

Top-level variables, top-level function names, type names, member names, etc.
are unchanged. They can be named `_` and used as they are today.

These are a few examples of where wildcard variables can be used:
```dart
Foo(_, this._, super._, void _()) {}

typedef T = void Function(String _, String _);

main() {
  var _ = 1;
  int _ = 2;

  list.where((_) => true);
}
```

Bug: https://github.com/dart-lang/sdk/issues/55673
Fixes: https://github.com/dart-lang/sdk/issues/55654
Change-Id: I80e904d39b364f5e54b8406b4db02ec40ecc9db0
TEST=Existing tests, language tests for wildcards.
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/381311
Reviewed-by: Mark Zhou <markzipan@google.com>
Reviewed-by: Mayank Patke <fishythefish@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Kallen Tu <kallentu@google.com>
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Bob Nystrom <rnystrom@google.com>

https://dart.googlesource.com/sdk/+/1bf5482e1e35ba1b0ccee299887812e6410aa026