34765c97d7
We now use `mapM`, `foldlM`, ... like Haskell. Motivation: fixes the inconsistent naming convetion. We are already using the `M` suffix for functions such as `anyM`. We used `anyM` because `many` is a valid English word. cc @kha @dselsam
50 lines
1.5 KiB
Text
50 lines
1.5 KiB
Text
/-
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Copyright (c) 2019 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Leonardo de Moura
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-/
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prelude
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import Init.Control.Id
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universes u v w
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/- List-like type to avoid extra level of indirection -/
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inductive AssocList (α : Type u) (β : Type v)
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| nil {} : AssocList
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| cons (key : α) (value : β) (tail : AssocList) : AssocList
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namespace AssocList
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variables {α : Type u} {β : Type v} {δ : Type w} {m : Type w → Type w} [Monad m]
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def empty : AssocList α β :=
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nil
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@[specialize] def foldlM (f : δ → α → β → m δ) : δ → AssocList α β → m δ
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| d, nil => pure d
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| d, cons a b es => do d ← f d a b; foldlM d es
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@[inline] def foldl (f : δ → α → β → δ) (d : δ) (as : AssocList α β) : δ :=
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Id.run (foldlM f d as)
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def find [HasBeq α] (a : α) : AssocList α β → Option β
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| nil => none
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| cons k v es => match k == a with
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| true => some v
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| false => find es
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def contains [HasBeq α] (a : α) : AssocList α β → Bool
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| nil => false
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| cons k v es => k == a || contains es
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def replace [HasBeq α] (a : α) (b : β) : AssocList α β → AssocList α β
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| nil => nil
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| cons k v es => match k == a with
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| true => cons a b es
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| false => cons k v (replace es)
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def erase [HasBeq α] (a : α) : AssocList α β → AssocList α β
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| nil => nil
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| cons k v es => match k == a with
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| true => es
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| false => cons k v (erase es)
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end AssocList
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