lean4-htt/library/init/list_classes.lean
2016-09-24 16:38:39 -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.
Author: Leonardo de Moura
-/
prelude
import init.monad init.alternative
open list
universe variables u v
@[inline] def list_fmap {A : Type u} {B : Type v} (f : A → B) (l : list A) : list B :=
map f l
@[inline] def list_bind {A : Type u} {B : Type v} (a : list A) (b : A → list B) : list B :=
join (map b a)
@[inline] def list_return {A : Type u} (a : A) : list A :=
[a]
instance : monad list :=
⟨@list_fmap, @list_return, @list_bind⟩
instance : alternative list :=
⟨@list_fmap, @list_return, @fapp _ _, @nil, @list.append⟩