f7de0c408f
This PR improves the error message when `initialize` (or `opaque`) fails to find an `Inhabited` or `Nonempty` instance. **Before:** ``` failed to synthesize Inhabited Foo ``` **After:** ``` failed to synthesize 'Inhabited' or 'Nonempty' instance for Foo If this type is defined using the 'structure' or 'inductive' command, you can try adding a 'deriving Nonempty' clause to it. ``` Prompted by https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/initialize.20structure.20with.20IO.2ERef/near/564936030 🤖 Prepared with Claude Code --------- Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
27 lines
1.5 KiB
Text
27 lines
1.5 KiB
Text
sanitychecks.lean:1:8-1:15: error: fail to show termination for
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unsound
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with errors
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failed to infer structural recursion:
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no parameters suitable for structural recursion
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well-founded recursion cannot be used, `unsound` does not take any (non-fixed) arguments
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sanitychecks.lean:4:8-4:32: error: 'partial' theorems are not allowed, 'partial' is a code generation directive
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sanitychecks.lean:7:7-7:31: error: 'unsafe' theorems are not allowed
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sanitychecks.lean:10:0-10:23: error: failed to synthesize 'Inhabited' or 'Nonempty' instance for
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False
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If this type is defined using the 'structure' or 'inductive' command, you can try adding a 'deriving Nonempty' clause to it.
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sanitychecks.lean:18:12-18:20: error: invalid use of `partial`, `Foo.unsound3` is not a function
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False
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sanitychecks.lean:20:0-20:54: error: failed to compile 'partial' definition `Foo.unsound4`, could not prove that the type
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∀ (x : Unit), False
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is nonempty.
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This process uses multiple strategies:
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- It looks for a parameter that matches the return type.
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- It tries synthesizing 'Inhabited' and 'Nonempty' instances for the return type, while making every parameter into a local 'Inhabited' instance.
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- It tries unfolding the return type.
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If the return type is defined using the 'structure' or 'inductive' command, you can try adding a 'deriving Nonempty' clause to it.
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sanitychecks.lean:22:12-22:20: error: (kernel) invalid declaration, it uses unsafe declaration 'unsafeCast'
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sanitychecks.lean:25:12-25:20: error: (kernel) invalid declaration, it uses unsafe declaration 'unsafeCast'
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