30 lines
800 B
Text
30 lines
800 B
Text
/-
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Copyright (c) 2019 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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Authors: Leonardo de Moura
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-/
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universe u
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namespace Lean
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inductive LOption (α : Type u) where
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| none : LOption α
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| some : α → LOption α
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| undef : LOption α
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deriving Inhabited, BEq
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instance [ToString α] : ToString (LOption α) where
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toString
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| LOption.none => "none"
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| LOption.undef => "undef"
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| LOption.some a => "(some " ++ toString a ++ ")"
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end Lean
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def Option.toLOption {α : Type u} : Option α → Lean.LOption α
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| none => Lean.LOption.none
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| some a => Lean.LOption.some a
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@[inline] def toLOptionM {α} {m : Type → Type} [Monad m] (x : m (Option α)) : m (Lean.LOption α) := do
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let b ← x
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pure b.toLOption
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