db6aa9d8d3
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>
84 lines
1.7 KiB
Text
84 lines
1.7 KiB
Text
module
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set_option warn.classDefReducibility false
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inductive Foo (α : Type u) (β : Type v) where
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| mk₁ : α → Foo α β
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| mk₂ : List β → Foo α β
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deriving instance Inhabited for Foo
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def ex1 : Inhabited (Foo α β) :=
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inferInstance
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inductive Bla (α : Type u) (β : Type v) where
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| mk₁ : α → Bla α β
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| mk₂ : β → Bla α β
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deriving instance Inhabited for Bla
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def ex2 [Inhabited α] : Inhabited (Foo α β) :=
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inferInstance
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structure Point (α : Type) where
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x : α
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y : α
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deriving Inhabited
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def ex3 [Inhabited α] : Inhabited (Point α) :=
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inferInstance
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inductive Lst (α : Type) where
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| nil
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| cons : α → Lst α → Lst α
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deriving Inhabited
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def ex4 : Inhabited (Lst α) :=
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inferInstance
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mutual
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inductive FooLst (α : Type) where
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| nil
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| cons : Boo α → FooLst α → FooLst α
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deriving Inhabited
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inductive Boo (α : Type) where
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| node : FooLst α → Boo α
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deriving Inhabited
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end
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def ex5 : Inhabited (Boo α) :=
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inferInstance
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structure A where
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deriving Inhabited
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/--
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info: @[implicit_reducible] private def instInhabitedA : Inhabited A :=
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{ default := instInhabitedA.default }
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-/
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#guard_msgs in
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#print instInhabitedA
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/-! Public structures with private fields should yield public opaque instances. -/
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public structure PrivField where
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private a : Nat
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deriving Inhabited
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/-- info: instInhabitedPrivField.default -/
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#guard_msgs in
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#with_exporting
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#reduce (default : PrivField)
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/-! ...which should not be compatible with explicit `@[expose]`. -/
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/--
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error: cannot use `deriving ... @[expose]` with `PrivFieldExp` as it has one or more private constructors
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-/
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#guard_msgs in
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public structure PrivFieldExp where
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private a : Nat
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deriving @[expose] Inhabited
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