c98b3a5388
When inductives are indirectly mutually recursive, say `inductive T | t (args: List T)` instead of `inductive T | t (arg : T)`, Lean would fail to find an instance of Hashable for `T` because it was not yet defined. This commit makes sure that the deriving handler adds a needed Hashable T instance to the local scope so that Hashable.hash can be resolved recursively.
39 lines
1 KiB
Text
39 lines
1 KiB
Text
structure Foo where
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name : String
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val : List Nat
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lower : Nat := List.length val
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inv : val.length >= lower
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flag : Bool
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deriving Hashable
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#eval hash <| { name := "Joe", val := List.iota 40, flag := true, inv := by decide : Foo }
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inductive Tree (α : Type) where
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| node : List (Tree α) → Bool → Tree α
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| leaf : α → Tree α
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deriving Hashable
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#eval hash <| Tree.node (List.iota 10 |>.map fun i => Tree.node [Tree.leaf i] (i%2==0)) true
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inductive StructureLikeInductive where
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| field : Nat -> StructureLikeInductive
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deriving Hashable
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#eval StructureLikeInductive.field 5 |> hash
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namespace Foo
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mutual
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inductive Tree (α : Type u) where
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| node : TreeList α → Tree α
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| leaf : α → Tree α
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deriving Hashable
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inductive TreeList (α : Type u) where
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| nil : TreeList α
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| cons : Tree α → TreeList α → TreeList α
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deriving Hashable
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end
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#eval hash <| Tree.node (TreeList.cons (Tree.leaf 30) (TreeList.cons (Tree.leaf 20) (TreeList.cons (Tree.leaf 10) TreeList.nil)))
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end Foo
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