lean4-htt/library/Init/Control/Conditional.lean
Leonardo de Moura a2abbdbf9a chore: fix imports using script
This is just a draft.
```
for f in `find . -name '*.lean'`; do echo $f; gsed "/^import/s/\b\(.\)/\u\1/g" $f > tmp; gsed "/^Import/s/Import/import/g" tmp > $f; done
```
2019-10-04 14:34:58 -07:00

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/-
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
-/
prelude
import Init.Control.Monad
import Init.Data.Option.Basic
universes u v
class HasToBool (α : Type u) :=
(toBool : α → Bool)
export HasToBool (toBool)
instance : HasToBool Bool := ⟨id⟩
instance {α} : HasToBool (Option α) := ⟨Option.toBool⟩
@[macroInline] def bool {β : Type u} {α : Type v} [HasToBool β] (f t : α) (b : β) : α :=
match toBool b with
| true => t
| false => f
@[macroInline] def orM {m : Type u → Type v} {β : Type u} [Monad m] [HasToBool β] (x y : m β) : m β :=
do b ← x;
match toBool b with
| true => pure b
| false => y
@[macroInline] def andM {m : Type u → Type v} {β : Type u} [Monad m] [HasToBool β] (x y : m β) : m β :=
do b ← x;
match toBool b with
| true => y
| false => pure b
infixl ` <||> `:30 := orM
infixl ` <&&> `:35 := andM
@[macroInline] def notM {m : Type → Type v} [Applicative m] (x : m Bool) : m Bool :=
not <$> x