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This PR adds a warning to any `def` of class type that does not also declare an appropriate reducibility. The warning check runs after elaboration (checking the actual reducibility status via `getReducibilityStatus`) rather than syntactically checking modifiers before elaboration. This is necessary to accommodate patterns like `@[to_additive (attr := implicit_reducible)]` in Mathlib, where the reducibility attribute is applied during `.afterCompilation` by another attribute, and would be missed by a purely syntactic check. --------- Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com> Co-authored-by: Kim Morrison <kim@tqft.net> Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
6 lines
355 B
Plaintext
6 lines
355 B
Plaintext
2273.lean:9:8-9:14: error(lean.synthInstanceFailed): failed to synthesize instance of type class
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P 37
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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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2273.lean:24:0-24:31: warning: Definition `instP` of class type must be marked with `@[reducible]` or `@[implicit_reducible]`
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