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

104 lines
3.3 KiB
Text
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/-
Copyright (c) 2019 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
-/
universe u v w w'
namespace Std
/- List-like type to avoid extra level of indirection -/
inductive AssocList (α : Type u) (β : Type v) where
| nil : AssocList α β
| cons (key : α) (value : β) (tail : AssocList α β) : AssocList α β
deriving Inhabited
namespace AssocList
variable {α : Type u} {β : Type v} {δ : Type w} {m : Type w → Type w} [Monad m]
abbrev empty : AssocList α β :=
nil
instance : EmptyCollection (AssocList α β) := ⟨empty⟩
abbrev insert (m : AssocList α β) (k : α) (v : β) : AssocList α β :=
m.cons k v
def isEmpty : AssocList α β → Bool
| nil => true
| _ => false
@[specialize] def foldlM (f : δ → α → β → m δ) : (init : δ) → AssocList α β → m δ
| d, nil => pure d
| d, cons a b es => do
let d ← f d a b
foldlM f d es
@[inline] def foldl (f : δ → α → β → δ) (init : δ) (as : AssocList α β) : δ :=
Id.run (foldlM f init as)
@[specialize] def forM (f : α → β → m PUnit) : AssocList α β → m PUnit
| nil => pure ⟨⟩
| cons a b es => do f a b; forM f es
def mapKey (f : α → δ) : AssocList α β → AssocList δ β
| nil => nil
| cons k v t => cons (f k) v (mapKey f t)
def mapVal (f : β → δ) : AssocList α β → AssocList α δ
| nil => nil
| cons k v t => cons k (f v) (mapVal f t)
def findEntry? [BEq α] (a : α) : AssocList α β → Option (α × β)
| nil => none
| cons k v es => match k == a with
| true => some (k, v)
| false => findEntry? a es
def find? [BEq α] (a : α) : AssocList α β → Option β
| nil => none
| cons k v es => match k == a with
| true => some v
| false => find? a es
def contains [BEq α] (a : α) : AssocList α β → Bool
| nil => false
| cons k v es => k == a || contains a es
def replace [BEq α] (a : α) (b : β) : AssocList α β → AssocList α β
| nil => nil
| cons k v es => match k == a with
| true => cons a b es
| false => cons k v (replace a b es)
def erase [BEq α] (a : α) : AssocList α β → AssocList α β
| nil => nil
| cons k v es => match k == a with
| true => es
| false => cons k v (erase a es)
def any (p : α → β → Bool) : AssocList α β → Bool
| nil => false
| cons k v es => p k v || any p es
def all (p : α → β → Bool) : AssocList α β → Bool
| nil => true
| cons k v es => p k v && all p es
@[inline] protected def forIn {α : Type u} {β : Type v} {δ : Type w} {m : Type w → Type w'} [Monad m]
(as : AssocList α β) (init : δ) (f : (α × β) → δ → m (ForInStep δ)) : m δ :=
let rec @[specialize] loop
| d, nil => pure d
| d, cons k v es => do
match (← f (k, v) d) with
| ForInStep.done d => pure d
| ForInStep.yield d => loop d es
loop init as
instance : ForIn m (AssocList α β) (α × β) where
forIn := AssocList.forIn
end Std.AssocList
def List.toAssocList {α : Type u} {β : Type v} : List (α × β) → Std.AssocList α β
| [] => Std.AssocList.nil
| (a,b) :: es => Std.AssocList.cons a b (toAssocList es)