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