This is in preparation to migrate package:kernel to null safety.
For the visitor interfaces to support non-nullable return types, the
implementations must avoid using `null` as return value in its base case.
TEST=Refactoring
Change-Id: Ie8fa5d41b99850d9e4abb59634c72920c64128d9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/183691
Reviewed-by: Jens Johansen <jensj@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>
This is in preparation to migrate package:kernel to null safety.
For the visitor interfaces to support non-nullable return types, the
implementations must avoid using `null` as return value in its base case.
TEST=Refactoring
Change-Id: Ie5e4153f8d3779d94957bb13b3d2d2a942040ff2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/179760
Commit-Queue: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>
This is in preparation to migrate package:kernel to null safety.
For the visitor interfaces to support non-nullable return types, the
implementations must avoid using `null` as return value in its base case.
TEST=Refactoring
Change-Id: I9f9b318982148d844be9826a5f8c88374a9fc402
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/172180
Commit-Queue: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>