f771dea78b
This PR fixes an issue where the "eta feature" in the app elaborator, which is invoked when positional arguments are skipped due to named arguments, results in variables that can be captured by those named arguments. Now the temporary local variables that implement this feature get fresh names. The names used for the closed lambda expression still use the original parameter names. Closes #6373
23 lines
468 B
Text
23 lines
468 B
Text
/-!
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# Eta arguments had wrong context in "don't know how to synthesize implicit" errors
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https://github.com/leanprover/lean4/issues/5475
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-/
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set_option pp.mvars false
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/-!
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Formerly, argument `x` appeared as `_fvar.123`
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-/
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def f {α β : Type} (x: α) (y: β) : α := x
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/--
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error: don't know how to synthesize implicit argument `α`
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@f ?_ Nat x✝ Nat.zero
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context:
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⊢ Type
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---
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error: Failed to infer type of example
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-/
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#guard_msgs in
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example :=
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f (y := Nat.zero)
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