Handle active patterns with inferred function ty & unsolved range typar #18642
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That is, for an active pattern whose type is known to be a function type but whose range type is not yet solved, assume that it _could_ be solved to, e.g., another function type. This can show up in, e.g., an active pattern that is defined mutually-recursively with `and`, has no type annotations, and returns a lambda with `fun` or `function`.
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edgarfgp
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Jun 2, 2025
abonie
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Jun 2, 2025
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Description
Fixes #18638, originally introduced in #16846 (I think?).
Treat
(|P|) : 'a -> 'bsimilarly to(|P|) : 'a.That is, for an active pattern whose type is known to be a function type but whose range type is not yet solved, assume that it could be solved to, e.g., another function type. This can show up in, e.g., an active pattern that is defined mutually-recursively with
and, has no type annotations, and returns a lambda withfunorfunction.Checklist