Relude.List.NonEmpty

This module contains safe functions to work with list type in terms of NonEmpty.

Documentation

viaNonEmpty :: (NonEmpty a -> b) -> [a] -> Maybe b

For safe work with lists using functinons for NonEmpty.

>>> viaNonEmpty head [1]
Just 1
>>> viaNonEmpty head []
Nothing

whenNotNull :: Applicative f => [a] -> (NonEmpty a -> f ()) -> f ()

Performs given action over NonEmpty list if given list is non empty.

>>> whenNotNull [] $ \(b :| _) -> print (not b)
>>> whenNotNull [False,True] $ \(b :| _) -> print (not b)
True

whenNotNullM :: Monad m => m [a] -> (NonEmpty a -> m ()) -> m ()

Monadic version of whenNotNull.