22 lines
689 B
Text
22 lines
689 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 and Jared Roesch
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-/
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prelude
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import init.functor init.string init.trace
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structure monad [class] (m : Type → Type) extends functor m : Type :=
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(ret : Π {a:Type}, a → m a)
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(bind : Π {a b: Type}, m a → (a → m b) → m b)
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inline definition return {m : Type → Type} [monad m] {A : Type} (a : A) : m A :=
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monad.ret m a
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inline definition fapp {A B : Type} {m : Type → Type} [monad m] (f : m (A → B)) (a : m A) : m B :=
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do g ← f,
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b ← a,
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return (g b)
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infixr ` <*> `:100 := fapp
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infixl ` >>= `:100 := monad.bind
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