(c) Fumiaki Kinoshita 2015BSD3'Fumiaki Kinoshita <fumiexcel@gmail.com> provisional non-portable Trustworthy*-./3"Traversable containers which hold  are witherable.Like traverse7, but you can remove elements instead of updating them. traverse f "a  (  . f)A definition of ! must satisfy the following laws: identity ( . Just) "a  compositionCompose . fmap ( f) .  g "a  (Compose . fmap ( f) . g))Parametricity implies the naturality law: t .  f =  (t . f)   is   with its arguments flipped. zRemoves duplicate elements from a list, keeping only the first occurrence. This is exponentially quicker than using  from . jRemoves duplicate elements from a list, keeping only the first occurrence. This is usually faster than  <, especially for things that have a slow comparion (like )            !"#$%!&'witherable-0.1.2.3Data.Witherable Data.ListnubDataListChipped getChipped WitherablewithermapMaybe catMaybesfilterAfilterwitherMblightMordNubhashNub$fWitherableChipped$fApplicativeChipped$fWitherableSeq$fWitherableVector$fWitherableConst$fWitherableProxy$fWitherableHashMap$fWitherableMap$fWitherableIntMap$fWitherable[]$fWitherableEither$fWitherableMaybebase Data.MaybeMaybeGHC.BasefmapJustControl.ApplicativepureString