Modulepolysemy-plugin-0.4.5.2Haskell2010

Polysemy.Plugin.Fundep.Utils

valuesingleListToJust :: [a] -> Maybe a

Returns the head of the list iff there is exactly one element.

valuewhenA :: (Monad m, Alternative z) => Bool -> m a -> m (z a)

Like when, but in the context of an Alternative.

valuecountLength :: Eq a => [a] -> [(a, Int)]

Count the number of times a is present in the list.