85341d02ac
This PR gives a simpler semantics to `noncomputable`, improving predictability as well as preparing codegen to be moved into a separate build step without breaking immediate generation of error messages. Specifically, `noncomputable` is now needed whenever an axiom or another `noncomputable` def is used by a def except for the following special cases: * uses inside proofs, types, type formers, and constructor arguments corresponding to (fixed) inductive parameters are ignored * uses of functions marked `@[extern]/@[implemented_by]/@[csimp]` are ignored * for applications of a function marked `@[macro_inline]`, noncomputability of the inlining is instead inspected # Breaking change After this change, more `noncomputable` annotations than before may be required in exchange for improved future stability.
21 lines
706 B
Text
21 lines
706 B
Text
/-!
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Tests that `@[csimp]` rejects constant replacements with concrete universe parameters
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-/
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noncomputable def funnyChoice (x : α) : α := Classical.choice ⟨x⟩
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/--
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error: invalid 'csimp' theorem, only constant replacement theorems (e.g., `@f = @g`) are currently supported.
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-/
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#guard_msgs in
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@[csimp]
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theorem bad_csimp : @funnyChoice.{0} = @id.{0} := rfl
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/--
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error: Tactic `native_decide` failed. Error: failed to compile definition, consider marking it as 'noncomputable' because it depends on 'funnyChoice', which is 'noncomputable'
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-/
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#guard_msgs in
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example : False := by
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have : funnyChoice 2 = funnyChoice 3 := rfl
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have : funnyChoice 2 ≠ funnyChoice 3 := by native_decide
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contradiction
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