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42 lines
1.0 KiB
Idris
42 lines
1.0 KiB
Idris
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module Data.Linear.Notation
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%default total
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infixr 0 -@
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||| Infix notation for linear implication
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public export
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(-@) : Type -> Type -> Type
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a -@ b = (1 _ : a) -> b
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||| An interface for consumable types
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public export
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interface Consumable a where
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consume : a -@ ()
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||| Void and the unit type are trivially consumable
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export
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Consumable Void where consume v impossible
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export
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Consumable () where consume u = u
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||| Unions can be consumed by pattern matching
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export
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Consumable Bool where
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consume True = ()
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consume False = ()
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||| We can cheat to make built-in types consumable
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export
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Consumable Int where
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consume = believe_me (\ 0 i : Int => ())
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-- But crucially we don't have `Consumable World` or `Consumable Handle`.
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infixr 5 `seq`
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||| consumable with another computation. This is done by first consuming
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||| the result of the first computation and then returning the second one.
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export
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seq : Consumable a => a -@ b -@ b
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a `seq` b = let 1 () = consume a in b
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