22 lines
740 B
Text
22 lines
740 B
Text
/-
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Copyright (c) 2016 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.functor
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set_option new_elaborator true
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structure [class] {u₁ u₂} applicative (f : Type u₁ → Type u₂) extends functor f : Type (max u₁+1 u₂) :=
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(pure : Π {A : Type u₁}, A → f A)
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(seq : Π {A B : Type u₁}, f (A → B) → f A → f B)
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attribute [inline]
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definition pure {f : Type → Type} [applicative f] {A : Type} (a : A) : f A :=
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applicative.pure f a
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attribute [inline]
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definition {u} seq_app {A B : Type u} {f : Type → Type} [applicative f] (g : f (A → B)) (a : f A) : f B :=
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applicative.seq g a
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infixr ` <*> `:2 := seq_app
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