29 lines
810 B
Text
29 lines
810 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.category.monad init.category.alternative init.data.list.basic
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import init.meta.mk_dec_eq_instance
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open list
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universe variables u v
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@[inline] def list.bind {α : Type u} {β : Type v} (a : list α) (b : α → list β) : list β :=
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join (map b a)
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@[inline] def list.ret {α : Type u} (a : α) : list α :=
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[a]
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instance : monad list :=
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{map := @map, ret := @list.ret, bind := @list.bind}
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instance : alternative list :=
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⟨@map, @list.ret, @fapp _ _, @nil, @list.append⟩
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instance {α : Type u} [decidable_eq α] : decidable_eq (list α) :=
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by tactic.mk_dec_eq_instance
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instance : decidable_eq string :=
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list.decidable_eq
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