Agda.Utils.Null

Overloaded null and empty for collections and sequences.

Documentation

class Null a where

Methods

empty :: a

null :: a -> Bool

Satisfying null empty == True.

Instances

Null ByteString

Null [a]

Null (Set a)

Null (Seq a)

Null (Range' a)

Null (Map k a)

Testing for null.

ifNull :: Null a => a -> b -> (a -> b) -> b

ifNullM :: (Monad m, Null a) => m a -> m b -> (a -> m b) -> m b

whenNull :: (Monad m, Null a) => a -> m () -> m ()

unlessNull :: (Monad m, Null a) => a -> (a -> m ()) -> m ()

whenNullM :: (Monad m, Null a) => m a -> m () -> m ()

unlessNullM :: (Monad m, Null a) => m a -> (a -> m ()) -> m ()