995fa4766b
This PR refines the new wording of the "application type mismatch" error message to avoid ambiguity in references to the "final" argument in a subexpression that may be followed by additional arguments. It does so by replacing "final" with "last," rephrasing the message so that this adjective modifies the argument itself rather than the word "argument," and only displaying this wording when two arguments could be confused (determined by expression equality). These changes were motivated by a report that in cases where a function application `f a b c` fails to elaborate because `b` is incorrectly typed, the existing error message's reference to `b` being the "final" argument in the application `f a b` may create confusion because it is not the final argument in the full application expression.
62 lines
1.2 KiB
Text
62 lines
1.2 KiB
Text
/-!
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# Check types when pretty printing dot notation for structure projections
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In type mismatch errors, the 'object of dot notation' might not be valid for dot notation.
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-/
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structure Foo : Type where
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out : Nat
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/-!
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Was printing `true.out`, but it should have been `Foo.out true`.
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-/
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/--
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error: Application type mismatch: In the application
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Foo.out true
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the argument
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true
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has type
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Bool : Type
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but is expected to have type
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Foo : Type
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---
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info: sorry.out : Nat
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-/
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#guard_msgs in #check Foo.out true
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/-!
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Verifying that generalized field notation does not have this bug.
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-/
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def Foo.out' (f : Foo) : Nat := f.out
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/--
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error: Application type mismatch: In the application
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Foo.out' true
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the argument
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true
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has type
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Bool : Type
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but is expected to have type
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Foo : Type
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---
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info: sorry.out' : Nat
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-/
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#guard_msgs in #check Foo.out' true
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/-!
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Verifying that projection notation still pretty prints as normal.
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-/
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section
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variable (f : Foo)
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/-- info: f.out : Nat -/
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#guard_msgs in #check f.out
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end
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/-!
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Verifying that projection notation still pretty prints through type synonys.
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-/
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section
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def Baz := Foo
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variable (f : Baz)
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/-- info: f.out : Nat -/
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#guard_msgs in #check f.out
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end
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