| Copyright | (c) 2016 Stephen Diehl (c) 20016-2018 Serokell (c) 2018 Kowainik |
|---|---|
| License | MIT |
| Maintainer | Kowainik <xrom.xkov@gmail.com> |
| Safe Haskell | Safe |
| Language | Haskell2010 |
Relude.List.NonEmpty
Description
This module contains safe functions to work with list type in terms of NonEmpty.
Synopsis
- viaNonEmpty :: (NonEmpty a -> b) -> [a] -> Maybe b
- uncons :: [a] -> Maybe (a, [a])
- whenNotNull :: Applicative f => [a] -> (NonEmpty a -> f ()) -> f ()
- whenNotNullM :: Monad m => m [a] -> (NonEmpty a -> m ()) -> m ()
Documentation
viaNonEmpty :: (NonEmpty a -> b) -> [a] -> Maybe b Source #
For safe work with lists using functinons for NonEmpty.
>>>viaNonEmpty head [1]Just 1>>>viaNonEmpty head []Nothing
uncons :: [a] -> Maybe (a, [a]) Source #
Destructuring list into its head and tail if possible. This function is total.
>>>uncons []Nothing>>>uncons [1..5]Just (1,[2,3,4,5])>>>uncons (5 : [1..5]) >>= \(f, l) -> pure $ f == length lJust True
whenNotNull :: Applicative f => [a] -> (NonEmpty a -> f ()) -> f () Source #
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 () Source #
Monadic version of whenNotNull.