8424ddbb3e
This PR improves the “expected type mismatch” error message by omitting the type's types when they are defeq, and putting them into separate lines when not. I found it rather tediuos to parse the error message when the expected type is long, because I had to find the `:` in the middle of a large expression somewhere. Also, when both are of sort `Prop` or `Type` it doesn't add much value to print the sort (and it’s only one hover away anyways).
39 lines
891 B
Text
39 lines
891 B
Text
import Lean.PremiseSelection
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/--
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error: type mismatch
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Nat
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has type
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Type
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of sort `Type 1` but is expected to have type
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Lean.PremiseSelection.Selector
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of sort `Type`
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---
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error: Failed to elaborate Nat as a `MVarId → Config → MetaM (Array Suggestion)`.
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-/
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#guard_msgs in
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set_premise_selector Nat
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/--
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error: No premise selector registered. (Note the Lean does not provide a default premise selector, these must be installed by a downstream library.)
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-/
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#guard_msgs in
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example : True := by
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suggest_premises
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trivial
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set_premise_selector (fun _ _ => pure #[])
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/-- info: Premise suggestions: [] -/
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#guard_msgs in
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example : True := by
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suggest_premises
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trivial
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set_premise_selector Lean.PremiseSelection.random ⟨1,1⟩
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-- This would be an extremely fragile test (select 10 random constants!)
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-- so we do not use #guard_msgs.
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example : True := by
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suggest_premises
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trivial
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