úÎ(ÿ&F.      !"#$%&'()*+,-)A class for list types. % Every list has an underlying monad. :Transform an action returning a list to the returned list  > joinL $ Identity "hello"  "hello" ./  foldr for s.  the result and ' right side' values are monadic actions. Prepend an item to a 0 Convert a list to a 0  > fromList [] :: Maybe Int  Nothing  > fromList [5] :: Maybe Int  Just 5 filter for any MonadPlus  > filter (> 5) (Just 3)  Nothing An action to do foldl for s !Execute the monadic actions in a  7Transform a list of actions to a list of their results " > joinM [Identity 4, Identity 7]  [4,7] An action to transform a  to a list ! > runIdentity $ toList "hello!"  "hello!" ;Consume a list (execute its actions) and return its length ! > runIdentity $ lengthL [1,2,3]  3 LTransform the underlying monad of a list given a way to transform the monad  > import Data.List.Tree (bfs) M > bfs (transformListMonad (\(Identity x) -> [x, x]) "hey" :: ListT [] Char)  "hheeeeyyyyyyyy" *Consume all items and return the last one  > runIdentity $ lastL "hello"  'o'  9Merge many lists sorted by a criteria given the criteria V > mergeOn length [["hi", "hey", "hello"], ["cat", "falcon"], ["banana", "cucumber"]] 9 ["hi","cat","hey","hello","banana","falcon","cucumber"] !8Merge two lists sorted by a criteria given the criteria  > merge2On id "01568" "239"  "01235689" "#Monadic version of iterate. A Can be used to produce trees given a children of node function. # import Data.List.Tree (bfsLayers) H take 3 $ bfsLayers (iterateM (\i -> [i*2, i*2+1]) [1] :: ListT [] Int)  [[1],[2,3],[4,5,6,7]] $listStateJoin can transform a  ListT (StateT s m) a to a StateT s m (ListT m a). FWhen iterating a list, a state is already maintained and passed along - in the form of the location along the list.  This joins the inner StateT s into the list. 1 The list will fork the state given to it and won't share its changes. % Generalized % For List l => l (l a) -> l a use 1 &Genereralized & For "List l => (a -> l b) -> l a -> l b use 2 (monadic bind) '  !"#$%&' %& ! #"$'  !"#$%&'()34'()'()'()()'()'()*+,-*+,-*+,-*+,-5      !"#$%&'()*+,,-(#./01201301456 List-0.4.1Data.List.ClassControl.Monad.Trans.ListControl.Monad.Trans.List.FuncsControl.Monad.ListTListItemMrunListjoinLListItemConsheadLtailLNilfoldrLconsfromListfilterfoldlLfoldl1Lscanlscanl1 genericTakeexecutejoinMmapL takeWhilerepeatM takeWhileMtoListlengthLtransformListMonadzipzipWithlastLrepeat transposemergeOnmerge2OnsortOniterateM listStateJoinconcat concatMapListTrunListTdeconstructListdeconstructList'base Control.Monad MonadPlusjoin=<<foldrL'