lean4-htt/src/Init/Data/Hashable.lean
2021-06-29 17:14:52 -07:00

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/-
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
-/
prelude
import Init.Data.UInt
import Init.Data.String
universe u
instance : Hashable Nat where
hash n := UInt64.ofNat n
instance [Hashable α] [Hashable β] : Hashable (α × β) where
hash | (a, b) => mixHash (hash a) (hash b)
instance : Hashable Bool where
hash
| true => 11
| false => 13
instance [Hashable α] : Hashable (Option α) where
hash
| none => 11
| some a => mixHash (hash a) 13
instance [Hashable α] : Hashable (List α) where
hash as := as.foldl (fun r a => mixHash r (hash a)) 7
instance : Hashable UInt32 where
hash n := n.toUInt64
instance : Hashable UInt64 where
hash n := n
instance : Hashable USize where
hash n := n.toUInt64
instance : Hashable Int where
hash
| Int.ofNat n => UInt64.ofNat (2 * n)
| Int.negSucc n => UInt64.ofNat (2 * n + 1)
instance (P : Prop) : Hashable P where
hash p := 0