24 lines
881 B
Text
24 lines
881 B
Text
/-
|
||
Copyright (c) Luke Nelson and Jared Roesch. All rights reserved.
|
||
Released under Apache 2.0 license as described in the file LICENSE.
|
||
Authors: Luke Nelson, Jared Roesch, Sebastian Ullrich, Leonardo de Moura
|
||
-/
|
||
prelude
|
||
import init.core
|
||
open Function
|
||
universes u v
|
||
|
||
class Functor (f : Type u → Type v) : Type (max (u+1) v) :=
|
||
(map : ∀ {α β : Type u}, (α → β) → f α → f β)
|
||
(mapConst : ∀ {α β : Type u}, α → f β → f α := fun α β => map ∘ const β)
|
||
|
||
infixr `<$>` := Functor.map
|
||
infixr `<$` := Functor.mapConst
|
||
|
||
@[reducible] def Functor.mapConstRev {f : Type u → Type v} [Functor f] {α β : Type u} : f β → α → f α :=
|
||
fun a b => b <$ a
|
||
infixr `$>` := Functor.mapConstRev
|
||
|
||
@[reducible] def Functor.mapRev {f : Type u → Type v} [Functor f] {α β : Type u} : f α → (α → β) → f β :=
|
||
fun a f => f <$> a
|
||
infixl `<&>` := Functor.mapRev
|