commit 15c02393441a743880c025947897ad71392ba3db
author Paul Berry <paulberry@google.com> Mon Jan 15 18:17:08 2024 +0000
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon Jan 15 18:17:08 2024 +0000
tree 9a10fdc1c3a3cfdce27c86205d20d42e0f9f15ae
parent 5ad284b1a4a5550cacf01d1cf22c2d15b83d4832

Fix context type for `==` and `!=` patterns.

According to the patterns spec
(https://github.com/dart-lang/language/blob/main/accepted/3.0/patterns/feature-specification.md),
if `A` is the type of the formal parameter of the operator
declaration, then operand should be type checked with context type
`A?` when op is `==` or `!=`, and with context type `A` otherwise.

Prior to this commit, context type `A` was always used.

There should be no observable behavior difference, because the operand
of a relational operator is required to be a constant expression, and
there is no constant expression that behaves differently when its
context is `A?` vs `A`.

However, we are contemplating some possible future language changes
that *would* make the difference observable (e.g.,
https://github.com/dart-lang/language/issues/3471), so it seems
prudent to fix the behavior to match the spec.

Change-Id: Ib3a1c82de45c65a851cbd613899ba1f72c215fbe
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/346420
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>