Approximate annotated types in wildApprox
#22893
Merged
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Fixes #22874.
wildApprox
approximates parameter references and type variables by wildcards. When doing so for anAnnotatedType
, this can produce trees with wildcards types, causing the type assigner to fail. For example, considerApply(fn, args)
wherefn
has typeTermParamRef
. ApplyingwildApprox
will approximate the type offn
to a wildcard, leading the type assigner forApply
to emit an error stating that<?>
does not take parameters.This issue is somehow similar to the one described in #19957 (comment), which was fixed by #21941 (and re-worked in #22839).
This PR fixes the issue by approximating annotated types in
wildApprox
: annotated types are approximated by their parent types if they are not refining, or by wildcards upper-bounded by their parent types if they are.