| definition: |
class Applicative f => Alternative f where
-- | The identity of '<|>'
empty :: f a
-- | An associative binary operation
(<|>) :: f a -> f a -> f a
-- | One or more.
some :: f a -> f [a]
some v = some_ v
where
many_ x = some_ x <|> pure []
some_ x = (:) <$> x <*> many_ x
-- | Zero or more.
many :: f a -> f [a]
many v = many_ v
where
many_ x = some_ x <|> pure []
some_ x = (:) <$> x <*> many_ x
|
| documentation: |
-- | A monoid on applicative functors. -- -- If defined, 'some' and 'many' should be the least solutions -- of the equations: -- -- * @'some' v = (:) '<$>' v '<*>' 'many' v@ -- -- * @'many' v = 'some' v '<|>' 'pure' []@ |
| methods: |
["empty :: a b","(<|>) :: a b -> a b -> a b","some 1 :: a b -> a [b]","many 1 :: a b -> a [b]"] |
| name: |
Alternative |