Open IOperation issues in recursive patterns

[gafter]

The following open issues relating to IOperation exist in the features/recursive-patterns branch after #31967 and #32018:

Addressed in #32018 and elsewhere

• Need to get some feedback on whether we should be using Tuples in the API here. We could potentially replace with a struct instead. IOperation for recursive pattern and switch expression #31967 (comment) [Moved to https://github.com/Tuples in public API of IRecursivePatternOperation #32756]
• Add additional verifications in tests for recursive patterns. IOperation for recursive pattern and switch expression #31967 (comment) [https://github.com/dotnet/roslyn/commit/511c06e0414a073e534f4e956deb083e5546e9ac]
• Testing around HasErrors scenarios, such as when there is no DeconstructSymbol but there are patterns. IOperation for recursive pattern and switch expression #31967 (comment) [https://github.com/dotnet/roslyn/commit/511c06e0414a073e534f4e956deb083e5546e9ac]
• Additional tests for CFG for switch expressions, including error scenarios.
• Add CFG tests for control-flow within a constant pattern within a recursive pattern within an is-expression.
  • @AlekseyTs says "The kind of test that would be interesting is a scenario with a control flow somewhere at the end of the recursive pattern, in the last sub-pattern, etc. I think the added test (IsPattern_ControlFlowInPattern_02) isn't a good representative of possible shortcomings of the current rewrite. It is not blocking for this PR, but please open an issue to follow-up on this subject." Since the test does precisely as requested, I am not sure what this is suggesting.
• switch expression IOperation still needs to be designed and implemented.
• The discard pattern should be a separate IOperation node from the discard expression. IOperation for recursive pattern and switch expression #31967 (comment)
• Could improve code slightly by using the SetParentOperation that takes an array IOperation for recursive pattern and switch expression #31967 (review)
• Remove DataFlow from test IOperation for recursive pattern and switch expression #31967 (comment)
• Use nameof to keep code in sync IOperation for recursive pattern and switch expression #31967 (comment) IOperation for recursive pattern and switch expression #31967 (comment) IOperation for recursive pattern and switch expression #31967 (comment)
• Rename d to p in foreach (var d in propertySubpatterns) [https://github.com/IOperation for recursive pattern and switch expression #31967#discussion_r244034690]
• IPatternOperation.InputType should be printed in IOperation tests.
• Revert the change to VisitArray to permit default arrays. IOperation for recursive pattern and switch expression #31967 (comment)

[gafter]

Closing, as there are no longer any items on this list.