34bd6e8bfd
This PR improves the error messages produced by the `split` tactic, including suggesting syntax fixes and related tactics with which it might be confused. Note that, to avoid clashing with the new error message styling conventions used in these messages, this PR also updates the formatting of the message produced by `throwTacticEx`. Closes #6224
49 lines
907 B
Text
49 lines
907 B
Text
/-!
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# Testing the autoparam feature
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-/
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def f (x y : Nat) (h : x = y := by assumption) : Nat :=
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x + x
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def g (x y z : Nat) (h : x = y) : Nat :=
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f x y
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def f2 (x y : Nat) (h : x = y := by exact rfl) : Nat :=
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x + x
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def f3 (x y : Nat) (h : x = y := by exact Eq.refl x) : Nat :=
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x + x
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#check fun x => f2 x x
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#check fun x => f3 x x
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/--
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error: could not synthesize default value for parameter 'h' using tactics
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---
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error: Tactic `assumption` failed
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⊢ 1 = 2
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-/
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#guard_msgs in example := f 1 2
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/-!
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From #2950, field autoparam should mention which field failed.
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-/
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structure Foo where
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val : String
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len : Nat := val.length
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inv : val.length = len := by next => decide
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/--
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error: could not synthesize default value for field 'inv' of 'Foo' using tactics
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---
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error: tactic 'decide' proved that the proposition
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"abc".length = 5
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is false
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-/
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#guard_msgs in
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def test2 : Foo := {
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val := "abc"
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len := 5
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}
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