3bd1dd633f
This PR causes Lean to search through `@[suggest_for]` annotations on certain errors that look like unknown identifiers that got incorrectly autobound. This will correctly identify that a declaration of type `Maybe String` should be `Option String` instead. ## Example ``` example : Except String Unit := return .ok () ``` ``` Function expected at Result but this term has type ?m.1 Note: Expected a function because this term is being applied to the argument String Hint: The identifier `Result` is unknown, and Lean's `autoImplicit` option causes an unknown identifier to be treated as an implicitly bound variable with an unknown type. However, the unknown type cannot be a function, and a function is what Lean expects here. This is often the result of a typo or a missing `import` or `open` statement. Perhaps you meant `Except` in place of `Result`? ``` The last line is added by this PR.
69 lines
2.3 KiB
Text
69 lines
2.3 KiB
Text
set_option autoImplicit false
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/--
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error: Unknown identifier `ℕ`
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Note: It is not possible to treat `ℕ` as an implicitly bound variable here because the `autoImplicit` option is set to `false`.
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Hint: Perhaps you meant `Nat` in place of `ℕ`:
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[apply] `Nat`
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-/
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#guard_msgs in example : ℕ := 3
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/--
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error: Unknown identifier `Result`
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Note: It is not possible to treat `Result` as an implicitly bound variable here because the `autoImplicit` option is set to `false`.
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Hint: Perhaps you meant `Except` in place of `Result`:
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[apply] `Except`
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-/
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#guard_msgs in example : Result String Nat := .ok 3
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set_option autoImplicit true
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-- The suggestion infrastructure doesn't help us here due to autobinding
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/--
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error: failed to synthesize instance of type class
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OfNat ℕ 3
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numerals are polymorphic in Lean, but the numeral `3` cannot be used in a context where the expected type is
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ℕ
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due to the absence of the instance above
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Hint: Type class instance resolution failures can be inspected with the `set_option trace.Meta.synthInstance true` command.
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-/
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#guard_msgs in example : ℕ := 3
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/--
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@ +0:45...62
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error: Function expected at
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Result
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but this term has type
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?m.1
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Note: Expected a function because this term is being applied to the argument
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String
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Hint: The identifier `Result` is unknown, and Lean's `autoImplicit` option causes an unknown identifier to be treated as an implicitly bound variable with an unknown type. However, the unknown type cannot be a function, and a function is what Lean expects here. This is often the result of a typo or a missing `import` or `open` statement.
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Perhaps you meant `Except` in place of `Result`?
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-/
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#guard_msgs (positions := true) in example : Result String Nat := .ok 3
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/--
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@ +0:45...62
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error: Function expected at
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Either
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but this term has type
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?m.1
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Note: Expected a function because this term is being applied to the argument
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String
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Hint: The identifier `Either` is unknown, and Lean's `autoImplicit` option causes an unknown identifier to be treated as an implicitly bound variable with an unknown type. However, the unknown type cannot be a function, and a function is what Lean expects here. This is often the result of a typo or a missing `import` or `open` statement.
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Perhaps you meant one of these in place of `Either`:
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• `Sum`
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• `Except`
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-/
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#guard_msgs (positions := true) in example : Either String Nat := .ok 3
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