Y      !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~      !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrs t u v w x y z { | } ~                                                                                                                                         (c) Ross Paterson 2005 (c) Louis Wasserman 2009 (c) Bertram Felgenhauer, David Feuer, Ross Paterson, and Milan Straka 2014 BSD-stylelibraries@haskell.org experimentalportable Trustworthy *+35>L[A  is a simple pairing heap.$View of the right end of a sequence.empty sequenceDthe sequence minus the rightmost element, and the rightmost element#View of the left end of a sequence.empty sequence-leftmost element and the rest of the sequence:This is essentially a clone of Control.Monad.State.Strict. VSometimes, we want to emphasize that we are viewing a node as a top-level digit of a   tree. 0A finger tree whose digits are all ones and twos 'A finger tree whose top level has only Two and/or Three digits, and whose other levels have only One and Two digits. A Rigid tree is precisely what one gets by unzipping/inverting a 2-3 tree, so it is precisely what we need to turn a finger tree into in order to transform it into a 2-3 tree.!General-purpose finite sequences.  ) does most of the hard work of computing fs *xs`. It produces the center part of a finger tree, with a prefix corresponding to the prefix of xs- and a suffix corresponding to the suffix of xs omitted; the missing suffix and prefix are added by the caller. For the recursive call, it squashes the prefix and the suffix into the center tree. Once it gets to the bottom, it turns the tree into a 2-3 tree, applies  > to produce the main body, and glues all the pieces together.map23 itself is a bit horrifying because of the nested types involved. Its job is to map over the *elements* of a 2-3 tree, rather than the subtrees. If we used a higher-order nested type with MPTC, we could probably use a class, but as it is we have to build up map23# explicitly through the recursion. O(m*n) (incremental) Takes an O(m)% function and a finger tree of size n> and maps the function over the tree leaves. Unlike the usual 2, the function is applied to the "leaves" of the  (i.e., given a FingerTree (Elem a)., it applies the function to elements of type Elem aJ), replacing the leaves with subtrees of at least the same height, e.g., Node(Node(Elem y))L. The multiplier argument serves to make the annotations match up properly.O(log n)4 (incremental) Takes the extra flexibility out of a 6 to make it a genuine 2-3 finger tree. The result of  will have only two and three digits at the top level and only one and two digits elsewhere. If the tree has fewer than four elements, 6 will simply extract them, and will not build a tree.O(log n)V (incremental) Takes a tree whose left side has been rigidified and finishes the job.O(log n)K (incremental) Rejigger a finger tree so the digits are all ones and twos.YGiven the size of a digit and the digit itself, efficiently converts it to a FingerTree. takes an Applicative-wrapped construction of a piece of a FingerTree, assumed to always have the same size (which is put in the second argument), and replicates it as many times as specified. This is a generalization of  B, which itself is a generalization of many Data.Sequence methods.O(1). The empty sequence.O(1). A singleton sequence. O(log n).  replicate n x is a sequence consisting of n copies of x.   is an  version of   , and makes O(log n) calls to  and . *replicateA n x = sequenceA (replicate n x)   is a sequence counterpart of  . )replicateM n x = sequence (replicate n x) n xs concatenates n copies of xs. O(1)p. Add an element to the left end of a sequence. Mnemonic: a triangle with the single element at the pointy end. O(1)q. Add an element to the right end of a sequence. Mnemonic: a triangle with the single element at the pointy end.O(log(min(n1,n2))). Concatenate two sequences._Builds a sequence from a seed value. Takes time linear in the number of generated elements. WARNING:R If the number of generated elements is infinite, this method will not terminate. f x is equivalent to : ( ( swap . f) x).O(n)P. Constructs a sequence by repeated application of a function to a seed value. @iterateN n f x = fromList (Prelude.take n (Prelude.iterate f x))O(1). Is this the empty sequence?O(1)). The number of elements in the sequence.O(1)%. Analyse the left end of a sequence.O(1)&. Analyse the right end of a sequence. is similar to :, but returns a sequence of reduced values from the left: Sscanl f z (fromList [x1, x2, ...]) = fromList [z, z `f` x1, (z `f` x1) `f` x2, ...] is a variant of % that has no starting value argument: Ascanl1 f (fromList [x1, x2, ...]) = fromList [x1, x1 `f` x2, ...] is the right-to-left dual of . is a variant of % that has no starting value argument.O(log(min(i,n-i))). The element at the specified position, counting from 0. The argument should thus be a non-negative integer less than the size of the sequence. If the position is out of range,  fails with an error.O(log(min(i,n-i)))u. Replace the element at the specified position. If the position is out of range, the original sequence is returned.O(log(min(i,n-i)))t. Update the element at the specified position. If the position is out of range, the original sequence is returned.O(n). A generalization of , v takes a mapping function that also depends on the element's index, and applies it to every element in the sequence.O(n)]. Convert a given sequence length and a function representing that sequence into a sequence.O(n)5. Create a sequence consisting of the elements of an . Note that the resulting sequence elements may be evaluated lazily (as on GHC), so you must force the entire structure to be sure that the original array can be garbage-collected. O(log(min(i,n-i))) . The first i elements of a sequence. If i is negative,   i sA yields the empty sequence. If the sequence contains fewer than i+ elements, the whole sequence is returned.!O(log(min(i,n-i)))). Elements of a sequence after the first i. If i is negative, ! i sA yields the whole sequence. If the sequence contains fewer than i+ elements, the empty sequence is returned."O(log(min(i,n-i)))). Split a sequence at a given position. " i s = (  i s, ! i s).(/O(log(min(i,n-i))) A strict version of ".#O(n)U. Returns a sequence of all suffixes of this sequence, longest first. For example, \tails (fromList "abc") = fromList [fromList "abc", fromList "bc", fromList "c", fromList ""]Evaluating the ith suffix takes O(log(min(i, n-i)))5, but evaluating every suffix in the sequence takes O(n) due to sharing.$O(n)V. Returns a sequence of all prefixes of this sequence, shortest first. For example, \inits (fromList "abc") = fromList [fromList "", fromList "a", fromList "ab", fromList "abc"]Evaluating the ith prefix takes O(log(min(i, n-i)))5, but evaluating every prefix in the sequence takes O(n) due to sharing.iGiven a function to apply to tails of a tree, applies that function to every tail of the specified tree.iGiven a function to apply to inits of a tree, applies that function to every init of the specified tree.%% is a version of 9 that also provides access to the index of each element.&& is a version of 9 that also provides access to the index of each element.'O(i) where i is the prefix length. ', applied to a predicate p and a sequence xs2, returns the longest prefix (possibly empty) of xs of elements that satisfy p.(O(i) where i is the suffix length. (, applied to a predicate p and a sequence xs2, returns the longest suffix (possibly empty) of xs of elements that satisfy p.( p xs is equivalent to : (' p (: xs)).)O(i) where i is the prefix length. ) p xs% returns the suffix remaining after ' p xs.*O(i) where i is the suffix length. * p xs% returns the prefix remaining after ( p xs.* p xs is equivalent to : () p (: xs)).+O(i) where i is the prefix length. +, applied to a predicate p and a sequence xsP, returns a pair whose first element is the longest prefix (possibly empty) of xs of elements that satisfy p9 and the second element is the remainder of the sequence.,O(i) where i is the suffix length. ,, applied to a predicate p and a sequence xs, returns a pair whose first element is the longest suffix (possibly empty) of xs of elements that satisfy p9 and the second element is the remainder of the sequence.-O(i) where i is the breakpoint index. -, applied to a predicate p and a sequence xsP, returns a pair whose first element is the longest prefix (possibly empty) of xs of elements that do not satisfy p: and the second element is the remainder of the sequence.- p is equivalent to + (not . p)... p is equivalent to , (not . p)./O(n). The / function takes a predicate p and a sequence xsT and returns sequences of those elements which do and do not satisfy the predicate.0O(n). The 0 function takes a predicate p and a sequence xsG and returns a sequence of those elements which satisfy the predicate.11U finds the leftmost index of the specified element, if it is present, and otherwise .22V finds the rightmost index of the specified element, if it is present, and otherwise .33[ finds the indices of the specified element, from left to right (i.e. in ascending order).44\ finds the indices of the specified element, from right to left (i.e. in descending order).55 p xs9 finds the index of the leftmost element that satisfies p, if any exist.66 p xs: finds the index of the rightmost element that satisfies p, if any exist.77 p, finds all indices of elements that satisfy p, in ascending order.88 p, finds all indices of elements that satisfy p, in descending order.9O(n)I. Create a sequence from a finite list of elements. There is a function  5 in the opposite direction for all instances of the ! class, including .:O(n). The reverse of a sequence."O(n). Constructs a new sequence with the same structure as an existing sequence using a user-supplied mapping function along with a splittable value and a way to split it. The value is split up lazily according to the structure of the sequence, so one piece of the value is distributed to each element of the sequence. The caller should provide a splitter function that takes a number, n5, and a splittable value, breaks off a chunk of size n from the value, and returns that chunk and the remainder as a pair. The following examples will hopefully make the usage clear: zipWith :: (a -> b -> c) -> Seq a -> Seq b -> Seq c zipWith f s1 s2 = splitMap splitAt (\b a -> f a (b `index` 0)) s2' s1' where minLen = min (length s1) (length s2) s1' = take minLen s1 s2' = take minLen s2 bmapWithIndex :: (Int -> a -> b) -> Seq a -> Seq b mapWithIndex f = splitMap (\n i -> (i, n+i)) f 0; O(min(n1,n2)). ; takes two sequences and returns a sequence of corresponding pairs. If one input is short, excess elements are discarded from the right end of the longer sequence.< O(min(n1,n2)). < generalizes ;i by zipping with the function given as the first argument, instead of a tupling function. For example,  zipWith (+)I is applied to two sequences to take the sequence of corresponding sums.#EA version of zipWith that assumes the sequences have the same length.=O(min(n1,n2,n3)). =H takes three sequences and returns a sequence of triples, analogous to ;.>O(min(n1,n2,n3)). > takes a function which combines three elements, as well as three sequences and returns a sequence of their point-wise combinations, analogous to <.?O(min(n1,n2,n3,n4)). ?J takes four sequences and returns a sequence of quadruples, analogous to ;.@O(min(n1,n2,n3,n4)). @ takes a function which combines four elements, as well as four sequences and returns a sequence of their point-wise combinations, analogous to <.A O(n log n). A sorts the specified _ by the natural ordering of its elements. The sort is stable. If stability is not required, CA can be considerably faster, and in particular uses less memory.B O(n log n). B sorts the specified ] according to the specified comparator. The sort is stable. If stability is not required, DA can be considerably faster, and in particular uses less memory.C O(n log n). C sorts the specified  by the natural ordering of its elements, but the sort is not stable. This algorithm is frequently faster and uses less memory than A>, and performs extremely well -- frequently twice as fast as A0 -- when the sequence is already nearly sorted.D O(n log n). A generalization of C, D takes an arbitrary comparator and sorts the specified sequence. The sort is not stable. This algorithm is frequently faster and uses less memory than B>, and performs extremely well -- frequently twice as fast as B0 -- when the sequence is already nearly sorted.$fromList2, given a list and its length, constructs a completely balanced Seq whose elements are that list using the replicateA generalization.%%), given a comparator function, unrolls a  into a sorted list.&&S, given an ordering function and a mechanism for queueifying elements, converts a  to a .'' merges two s.()*+,-./0123456789:;<=>?@AB CDE FGH IJKLMNOPQRSTU VWX YZ[\]^_`abcdefg h i jklmnopqrstuvwxyz{| !"}~#$%&'()*+,-./0123456789:";<#=>?@ABCD$%&'E  !"#$%&'()*+,-./0123456789:;<=>?@ABCDE 9 #$'()*+,-./0ABCD !"13245768%&:;<=>?@()*+,-./0123456789:;<=>?@AB CDE FGH IJKLMNOPQRSTU VWX YZ[\]^_`abcdefg h i jklmnopqrstuvwxyz{| !"}~#$%&'()*+,-./0123456789:";<#=>?@ABCD$%&' * i jk"(c) The University of Glasgow 2002/BSD-style (see the file libraries/base/LICENSE)libraries@haskell.org experimentalportable Trustworthy*+ FMulti-way trees, also known as  rose trees.H label valueIzero or more child treesJ%Neat 2-dimensional drawing of a tree.K'Neat 2-dimensional drawing of a forest.L$The elements of a tree in pre-order.M)Lists of nodes at each level of the tree.NBuild a tree from a seed valueO)Build a forest from a list of seed valuesP*Monadic tree builder, in depth-first orderQ,Monadic forest builder, in depth-first orderRPMonadic tree builder, in breadth-first order, using an algorithm adapted from JBreadth-First Numbering: Lessons from a Small Exercise in Algorithm Design, by Chris Okasaki, ICFP'00.SRMonadic forest builder, in breadth-first order, using an algorithm adapted from JBreadth-First Numbering: Lessons from a Small Exercise in Algorithm Design, by Chris Okasaki, ICFP'00.EFGHIJKLMNOPQRSEFGHIJKLMNOPQRSFGHIEJKLMNOPQRSEFGHIJKLMNOPQRS"(c) The University of Glasgow 2002/BSD-style (see the file libraries/base/LICENSE)libraries@haskell.org experimentalportable TrustworthyINT,An edge from the first vertex to the second.UThe bounds of a W.VYAdjacency list representation of a graph, mapping each vertex to its list of successors.W.Table indexed by a contiguous set of vertices.X$Abstract representation of vertices.YStrongly connected component.Z*A single vertex that is not in any cycle.[.A maximal set of mutually reachable vertices.\8The vertices of a list of strongly connected components.]/The vertices of a strongly connected component.^MThe strongly connected components of a directed graph, topologically sorted._kThe strongly connected components of a directed graph, topologically sorted. The function is the same as ^n, except that all the information about each node retained. This interface is used when you expect to apply Y to (some of) the result of Y8, so you don't want to lose the dependency information.`All vertices of a graph.aAll edges of a graph.b#Build a graph from a list of edges.c*The graph obtained by reversing all edges.d-A table of the count of edges from each node.e-A table of the count of edges into each node.f Identical to gm, except that the return value does not include the function which maps keys to vertices. This version of g is for backwards compatibility.gBuild a graph from a list of nodes uniquely identified by keys, with a list of keys of nodes this node should have edges to. The out-list may contain keys that don't correspond to nodes of the graph; they are ignored.hA spanning forest of the graph, obtained from a depth-first search of the graph starting from each vertex in an unspecified order.iA spanning forest of the part of the graph reachable from the listed vertices, obtained from a depth-first search of the graph starting at each of the listed vertices in order.jbA topological sort of the graph. The order is partially specified by the condition that a vertex i precedes j whenever j is reachable from i but not vice versa.kThe connected components of a graph. Two vertices are connected if there is a path between them, traversing edges in either direction.l-The strongly connected components of a graph.m1A list of vertices reachable from a given vertex.n.Is the second vertex reachable from the first?o~The biconnected components of a graph. An undirected graph is biconnected if the deletion of any vertex leaves it connected.8TUVWXYZ[\]^The graph: a list of nodes uniquely identified by keys, with a list of keys of nodes this node has edges to. The out-list may contain keys that don't correspond to nodes of the graph; such edges are ignored._The graph: a list of nodes uniquely identified by keys, with a list of keys of nodes this node has edges to. The out-list may contain keys that don't correspond to nodes of the graph; such edges are ignored.Topologically sorted`abcdefghijklmnoEFGTUVWXYZ[\]^_`abcdefghijklmno^_YZ[]\VWUTXgfbc`adeihjklomn4TUVWXYZ[\]^_`abcdefghijklmnoSafeCSame as regular Haskell pairs, but (x :*: _|_) = (_|_ :*: y) = _|_SafeSame as regular }, but marked INLINE so that it is always inlined. This allows further optimization of the call to f, which can be optimized specialisedinlined.(c) Daan Leijen 2002 BSD-stylelibraries@haskell.org provisionalportable Trustworthy*+>?L6pA set of values a.qO(n+m). See .rO(1). Is this the empty set?sO(1)$. The number of elements in the set.tO(log n). Is the element in the set?uO(log n) . Is the element not in the set?vO(log n)2. Find largest element smaller than the given one. NlookupLT 3 (fromList [3, 5]) == Nothing lookupLT 5 (fromList [3, 5]) == Just 3wO(log n)3. Find smallest element greater than the given one. NlookupGT 4 (fromList [3, 5]) == Just 5 lookupGT 5 (fromList [3, 5]) == NothingxO(log n)9. Find largest element smaller or equal to the given one. ulookupLE 2 (fromList [3, 5]) == Nothing lookupLE 4 (fromList [3, 5]) == Just 3 lookupLE 5 (fromList [3, 5]) == Just 5yO(log n):. Find smallest element greater or equal to the given one. ulookupGE 3 (fromList [3, 5]) == Just 3 lookupGE 4 (fromList [3, 5]) == Just 5 lookupGE 6 (fromList [3, 5]) == NothingzO(1). The empty set.{O(1). Create a singleton set.|O(log n). Insert an element in a set. If the set already contains an element equal to the given value, it is replaced with the new value.}O(log n). Delete an element from a set.~O(n+m)8. Is this a proper subset? (ie. a subset but not equal).O(n+m). Is this a subset? (s1  s2) tells whether s1 is a subset of s2.O(log n). The minimal element of a set.O(log n). The maximal element of a set.O(log n)G. Delete the minimal element. Returns an empty set if the set is empty.O(log n)G. Delete the maximal element. Returns an empty set if the set is empty.The union of a list of sets: ( ==   z).O(n+m). The union of two sets, preferring the first set when equal elements are encountered. The implementation uses the efficient  hedge-union algorithm.O(n+m)@. Difference of two sets. The implementation uses an efficient hedge algorithm comparable with  hedge-union.O(n+m)G. The intersection of two sets. The implementation uses an efficient hedge algorithm comparable with  hedge-unionB. Elements of the result come from the first set, so for example import qualified Data.Set as S data AB = A | B deriving Show instance Ord AB where compare _ _ = EQ instance Eq AB where _ == _ = True main = print (S.singleton A `S.intersection` S.singleton B, S.singleton B `S.intersection` S.singleton A)prints (fromList [A],fromList [B]).O(n)1. Filter all elements that satisfy the predicate.O(n). Partition the set into two sets, one with all elements that satisfy the predicate and one with all elements that don't satisfy the predicate. See also . O(n*log n).  f s! is the set obtained by applying f to each element of s.KIt's worth noting that the size of the result may be smaller if, for some (x,y), x /= y && f x == f yO(n). The f s ==  f s, but works only when f is monotonic.  The precondition is not checked. Semi-formally, we have: xand [x < y ==> f x < f y | x <- ls, y <- ls] ==> mapMonotonic f s == map f s where ls = toList sO(n)u. Fold the elements in the set using the given right-associative binary operator. This function is an equivalent of ( and is present for compatibility only.CPlease note that fold will be deprecated in the future and removed.O(n)]. Fold the elements in the set using the given right-associative binary operator, such that  f z ==  f z . . For example,  toAscList set = foldr (:) [] setO(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)\. Fold the elements in the set using the given left-associative binary operator, such that  f z ==  f z . . For example, (toDescList set = foldl (flip (:)) [] setO(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n). An alias of D. The elements of a set in ascending order. Subject to list fusion.O(n)@. Convert the set to a list of elements. Subject to list fusion.O(n)K. Convert the set to an ascending list of elements. Subject to list fusion.O(n)L. Convert the set to a descending list of elements. Subject to list fusion. O(n*log n)'. Create a set from a list of elements.bIf the elements are ordered, a linear-time implementation is used, with the performance equal to .O(n)6. Build a set from an ascending list in linear time. :The precondition (input list is ascending) is not checked.O(n)K. Build a set from an ascending list of distinct elements in linear time. CThe precondition (input list is strictly ascending) is not checked.O(log n). The expression ( x set ) is a pair  (set1,set2) where set1 comprises the elements of set less than x and set2 comprises the elements of set greater than x.O(log n) . Performs a K but also returns whether the pivot element was found in the original set.O(log n) . Return the indexn of an element, which is its zero-based index in the sorted sequence of elements. The index is a number from 0 up to, but not including, the s of the set. Calls  when the element is not a t of the set. findIndex 2 (fromList [5,3]) Error: element is not in the set findIndex 3 (fromList [5,3]) == 0 findIndex 5 (fromList [5,3]) == 1 findIndex 6 (fromList [5,3]) Error: element is not in the setO(log n) . Lookup the indexn of an element, which is its zero-based index in the sorted sequence of elements. The index is a number from 0 up to, but not including, the s of the set. isJust (lookupIndex 2 (fromList [5,3])) == False fromJust (lookupIndex 3 (fromList [5,3])) == 0 fromJust (lookupIndex 5 (fromList [5,3])) == 1 isJust (lookupIndex 6 (fromList [5,3])) == FalseO(log n). Retrieve an element by its indexK, i.e. by its zero-based index in the sorted sequence of elements. If the index7 is out of range (less than zero, greater or equal to s of the set),  is called. telemAt 0 (fromList [5,3]) == 3 elemAt 1 (fromList [5,3]) == 5 elemAt 2 (fromList [5,3]) Error: index out of rangeO(log n). Delete the element at indexK, i.e. by its zero-based index in the sorted sequence of elements. If the index7 is out of range (less than zero, greater or equal to s of the set),  is called. deleteAt 0 (fromList [5,3]) == singleton 5 deleteAt 1 (fromList [5,3]) == singleton 3 deleteAt 2 (fromList [5,3]) Error: index out of range deleteAt (-1) (fromList [5,3]) Error: index out of rangeO(log n)&. Delete and find the minimal element. 0deleteFindMin set = (findMin set, deleteMin set)O(log n)&. Delete and find the maximal element. 0deleteFindMax set = (findMax set, deleteMax set)O(log n)R. Retrieves the minimal key of the set, and the set stripped of that element, or  if passed an empty set.O(log n)R. Retrieves the maximal key of the set, and the set stripped of that element, or  if passed an empty set.O(1). Decompose a set into pieces based on the structure of the underlying tree. This function is useful for consuming a set in parallel.No guarantee is made as to the sizes of the pieces; an internal, but deterministic process determines this. However, it is guaranteed that the pieces returned will be in ascending order (all elements in the first subset less than all elements in the second, and so on). Examples: OsplitRoot (fromList [1..6]) == [fromList [1,2,3],fromList [4],fromList [5,6]] splitRoot empty == []Note that the current implementation does not return more than three subsets, but you should not depend on this behaviour because it can change in the future without notice.O(n)\. Show the tree that implements the set. The tree is shown in a compressed, hanging format.O(n). The expression (showTreeWith hang wide map.) shows the tree that implements the set. If hang is True, a hanging6 tree is shown otherwise a rotated tree is shown. If wide is !, an extra wide version is shown. ?Set> putStrLn $ showTreeWith True False $ fromDistinctAscList [1..5] 4 +--2 | +--1 | +--3 +--5 Set> putStrLn $ showTreeWith True True $ fromDistinctAscList [1..5] 4 | +--2 | | | +--1 | | | +--3 | +--5 Set> putStrLn $ showTreeWith False True $ fromDistinctAscList [1..5] +--5 | 4 | | +--3 | | +--2 | +--1O(n).. Test if the internal set structure is valid.epqrstuvwxyz{|}~     <pqrstuvwxyz{|}~apqrstuvwxyz{|}~     q @(c) Daan Leijen 2002 (c) Andriy Palamarchuk 2008 BSD-stylelibraries@haskell.org provisionalportable Trustworthy*+>?LoA Map from keys k to values a.O(log n)". Find the value at a key. Calls # when the element can not be found. gfromList [(5,'a'), (3,'b')] ! 1 Error: element not in the map fromList [(5,'a'), (3,'b')] ! 5 == 'a'Same as .O(1). Is the map empty? PData.Map.null (empty) == True Data.Map.null (singleton 1 'a') == FalseO(1)$. The number of elements in the map. size empty == 0 size (singleton 1 'a') == 1 size (fromList([(1,'a'), (2,'c'), (3,'b')])) == 3O(log n)'. Lookup the value at a key in the map.4The function will return the corresponding value as ( value), or  if the key isn't in the map.An example of using lookup: 7import Prelude hiding (lookup) import Data.Map employeeDept = fromList([("John","Sales"), ("Bob","IT")]) deptCountry = fromList([("IT","USA"), ("Sales","France")]) countryCurrency = fromList([("USA", "Dollar"), ("France", "Euro")]) employeeCurrency :: String -> Maybe String employeeCurrency name = do dept <- lookup name employeeDept country <- lookup dept deptCountry lookup country countryCurrency main = do putStrLn $ "John's currency: " ++ (show (employeeCurrency "John")) putStrLn $ "Pete's currency: " ++ (show (employeeCurrency "Pete"))The output of this program: 9 John's currency: Just "Euro" Pete's currency: NothingO(log n)+. Is the key a member of the map? See also . ^member 5 (fromList [(5,'a'), (3,'b')]) == True member 1 (fromList [(5,'a'), (3,'b')]) == FalseO(log n)/. Is the key not a member of the map? See also . dnotMember 5 (fromList [(5,'a'), (3,'b')]) == False notMember 1 (fromList [(5,'a'), (3,'b')]) == TrueO(log n)". Find the value at a key. Calls # when the element can not be found.O(log n). The expression ( def k map) returns the value at key k or returns default value def! when the key is not in the map. ufindWithDefault 'x' 1 (fromList [(5,'a'), (3,'b')]) == 'x' findWithDefault 'x' 5 (fromList [(5,'a'), (3,'b')]) == 'a'O(log n)^. Find largest key smaller than the given one and return the corresponding (key, value) pair. mlookupLT 3 (fromList [(3,'a'), (5,'b')]) == Nothing lookupLT 4 (fromList [(3,'a'), (5,'b')]) == Just (3, 'a')O(log n)_. Find smallest key greater than the given one and return the corresponding (key, value) pair. mlookupGT 4 (fromList [(3,'a'), (5,'b')]) == Just (5, 'b') lookupGT 5 (fromList [(3,'a'), (5,'b')]) == NothingO(log n)e. Find largest key smaller or equal to the given one and return the corresponding (key, value) pair. lookupLE 2 (fromList [(3,'a'), (5,'b')]) == Nothing lookupLE 4 (fromList [(3,'a'), (5,'b')]) == Just (3, 'a') lookupLE 5 (fromList [(3,'a'), (5,'b')]) == Just (5, 'b')O(log n)f. Find smallest key greater or equal to the given one and return the corresponding (key, value) pair. lookupGE 3 (fromList [(3,'a'), (5,'b')]) == Just (3, 'a') lookupGE 4 (fromList [(3,'a'), (5,'b')]) == Just (5, 'b') lookupGE 6 (fromList [(3,'a'), (5,'b')]) == NothingO(1). The empty map. )empty == fromList [] size empty == 0O(1). A map with a single element. Isingleton 1 'a' == fromList [(1, 'a')] size (singleton 1 'a') == 1O(log n). Insert a new key and value in the map. If the key is already present in the map, the associated value is replaced with the supplied value.  is equivalent to  . insert 5 'x' (fromList [(5,'a'), (3,'b')]) == fromList [(3, 'b'), (5, 'x')] insert 7 'x' (fromList [(5,'a'), (3,'b')]) == fromList [(3, 'b'), (5, 'a'), (7, 'x')] insert 5 'x' empty == singleton 5 'x'O(log n)>. Insert with a function, combining new value and old value.  f key value mp) will insert the pair (key, value) into mp^ if key does not exist in the map. If the key does exist, the function will insert the pair (key, f new_value old_value). insertWith (++) 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "xxxa")] insertWith (++) 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")] insertWith (++) 5 "xxx" empty == singleton 5 "xxx"O(log n)C. Insert with a function, combining key, new value and old value.  f key value mp) will insert the pair (key, value) into mp^ if key does not exist in the map. If the key does exist, the function will insert the pair (key,f key new_value old_value);. Note that the key passed to f is the same key passed to . ]let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")] insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")] insertWithKey f 5 "xxx" empty == singleton 5 "xxx"O(log n)G. Combines insert operation with old value retrieval. The expression ( f k x map2) is a pair where the first element is equal to ( k map$) and the second element equal to ( f k x map). let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value insertLookupWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "5:xxx|a")]) insertLookupWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a"), (7, "xxx")]) insertLookupWithKey f 5 "xxx" empty == (Nothing, singleton 5 "xxx")This is how to define  insertLookup using insertLookupWithKey: let insertLookup kx x t = insertLookupWithKey (\_ a _ -> a) kx x t insertLookup 5 "x" (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "x")]) insertLookup 7 "x" (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a"), (7, "x")])O(log n)r. Delete a key and its value from the map. When the key is not a member of the map, the original map is returned. delete 5 (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" delete 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] delete 5 empty == emptyO(log n). Update a value at a specific key with the result of the provided function. When the key is not a member of the map, the original map is returned. adjust ("new " ++) 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] adjust ("new " ++) 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] adjust ("new " ++) 7 empty == emptyO(log n)k. Adjust a value at a specific key. When the key is not a member of the map, the original map is returned.  let f key x = (show key) ++ ":new " ++ x adjustWithKey f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:new a")] adjustWithKey f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] adjustWithKey f 7 empty == emptyO(log n). The expression ( f k map) updates the value x at k (if it is in the map). If (f x) is %, the element is deleted. If it is ( y ), the key k is bound to the new value y. let f x = if x == "a" then Just "new a" else Nothing update f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] update f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] update f 3 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(log n). The expression ( f k map) updates the value x at k (if it is in the map). If (f k x) is %, the element is deleted. If it is ( y ), the key k is bound to the new value y. 0let f k x = if x == "a" then Just ((show k) ++ ":new a") else Nothing updateWithKey f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:new a")] updateWithKey f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] updateWithKey f 3 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(log n). Lookup and update. See also u. The function returns changed value, if it is updated. Returns the original key value if the map entry is deleted. llet f k x = if x == "a" then Just ((show k) ++ ":new a") else Nothing updateLookupWithKey f 5 (fromList [(5,"a"), (3,"b")]) == (Just "5:new a", fromList [(3, "b"), (5, "5:new a")]) updateLookupWithKey f 7 (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a")]) updateLookupWithKey f 3 (fromList [(5,"a"), (3,"b")]) == (Just "b", singleton 5 "a")O(log n). The expression ( f k map) alters the value x at k, or absence thereof. 7 can be used to insert, delete, or update a value in a . In short :  k ( f k m) = f ( k m). Elet f _ = Nothing alter f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] alter f 5 (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" let f _ = Just "c" alter f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "c")] alter f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "c")]O(log n) . Return the indexe of a key, which is its zero-based index in the sequence sorted by keys. The index is a number from 0 up to, but not including, the  of the map. Calls  when the key is not a  of the map. findIndex 2 (fromList [(5,"a"), (3,"b")]) Error: element is not in the map findIndex 3 (fromList [(5,"a"), (3,"b")]) == 0 findIndex 5 (fromList [(5,"a"), (3,"b")]) == 1 findIndex 6 (fromList [(5,"a"), (3,"b")]) Error: element is not in the mapO(log n) . Lookup the indexe of a key, which is its zero-based index in the sequence sorted by keys. The index is a number from 0 up to, but not including, the  of the map. isJust (lookupIndex 2 (fromList [(5,"a"), (3,"b")])) == False fromJust (lookupIndex 3 (fromList [(5,"a"), (3,"b")])) == 0 fromJust (lookupIndex 5 (fromList [(5,"a"), (3,"b")])) == 1 isJust (lookupIndex 6 (fromList [(5,"a"), (3,"b")])) == FalseO(log n). Retrieve an element by its indexG, i.e. by its zero-based index in the sequence sorted by keys. If the index7 is out of range (less than zero, greater or equal to  of the map),  is called. elemAt 0 (fromList [(5,"a"), (3,"b")]) == (3,"b") elemAt 1 (fromList [(5,"a"), (3,"b")]) == (5, "a") elemAt 2 (fromList [(5,"a"), (3,"b")]) Error: index out of rangeO(log n). Update the element at indexG, i.e. by its zero-based index in the sequence sorted by keys. If the index7 is out of range (less than zero, greater or equal to  of the map),  is called. updateAt (\ _ _ -> Just "x") 0 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "x"), (5, "a")] updateAt (\ _ _ -> Just "x") 1 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "x")] updateAt (\ _ _ -> Just "x") 2 (fromList [(5,"a"), (3,"b")]) Error: index out of range updateAt (\ _ _ -> Just "x") (-1) (fromList [(5,"a"), (3,"b")]) Error: index out of range updateAt (\_ _ -> Nothing) 0 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" updateAt (\_ _ -> Nothing) 1 (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" updateAt (\_ _ -> Nothing) 2 (fromList [(5,"a"), (3,"b")]) Error: index out of range updateAt (\_ _ -> Nothing) (-1) (fromList [(5,"a"), (3,"b")]) Error: index out of rangeO(log n). Delete the element at indexG, i.e. by its zero-based index in the sequence sorted by keys. If the index7 is out of range (less than zero, greater or equal to  of the map),  is called. deleteAt 0 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" deleteAt 1 (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" deleteAt 2 (fromList [(5,"a"), (3,"b")]) Error: index out of range deleteAt (-1) (fromList [(5,"a"), (3,"b")]) Error: index out of rangeO(log n)$. The minimal key of the map. Calls  if the map is empty. findMin (fromList [(5,"a"), (3,"b")]) == (3,"b") findMin empty Error: empty map has no minimal elementO(log n)$. The maximal key of the map. Calls  if the map is empty. findMax (fromList [(5,"a"), (3,"b")]) == (5,"a") findMax empty Error: empty map has no maximal elementO(log n)C. Delete the minimal key. Returns an empty map if the map is empty. hdeleteMin (fromList [(5,"a"), (3,"b"), (7,"c")]) == fromList [(5,"a"), (7,"c")] deleteMin empty == emptyO(log n)C. Delete the maximal key. Returns an empty map if the map is empty. hdeleteMax (fromList [(5,"a"), (3,"b"), (7,"c")]) == fromList [(3,"b"), (5,"a")] deleteMax empty == emptyO(log n)&. Update the value at the minimal key. updateMin (\ a -> Just ("X" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3, "Xb"), (5, "a")] updateMin (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(log n)&. Update the value at the maximal key. updateMax (\ a -> Just ("X" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "Xa")] updateMax (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 3 "b"O(log n)&. Update the value at the minimal key. updateMinWithKey (\ k a -> Just ((show k) ++ ":" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3,"3:b"), (5,"a")] updateMinWithKey (\ _ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(log n)&. Update the value at the maximal key. updateMaxWithKey (\ k a -> Just ((show k) ++ ":" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3,"b"), (5,"5:a")] updateMaxWithKey (\ _ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 3 "b"O(log n)_. Retrieves the minimal (key,value) pair of the map, and the map stripped of that element, or  if passed an empty map. ominViewWithKey (fromList [(5,"a"), (3,"b")]) == Just ((3,"b"), singleton 5 "a") minViewWithKey empty == NothingO(log n)_. Retrieves the maximal (key,value) pair of the map, and the map stripped of that element, or  if passed an empty map. omaxViewWithKey (fromList [(5,"a"), (3,"b")]) == Just ((5,"a"), singleton 3 "b") maxViewWithKey empty == NothingO(log n)h. Retrieves the value associated with minimal key of the map, and the map stripped of that element, or  if passed an empty map. ]minView (fromList [(5,"a"), (3,"b")]) == Just ("b", singleton 5 "a") minView empty == NothingO(log n)h. Retrieves the value associated with maximal key of the map, and the map stripped of that element, or  if passed an empty map. ]maxView (fromList [(5,"a"), (3,"b")]) == Just ("a", singleton 3 "b") maxView empty == Nothing!The union of a list of maps: ( ==   ). 9unions [(fromList [(5, "a"), (3, "b")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "A3"), (3, "B3")])] == fromList [(3, "b"), (5, "a"), (7, "C")] unions [(fromList [(5, "A3"), (3, "B3")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "a"), (3, "b")])] == fromList [(3, "B3"), (5, "A3"), (7, "C")]=The union of a list of maps, with a combining operation: ( f ==  ( f) ). unionsWith (++) [(fromList [(5, "a"), (3, "b")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "A3"), (3, "B3")])] == fromList [(3, "bB3"), (5, "aAA3"), (7, "C")]O(n+m). The expression ( t1 t2!) takes the left-biased union of t1 and t2. It prefers t1- when duplicate keys are encountered, i.e. ( ==  *). The implementation uses the efficient  hedge-union algorithm. punion (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "a"), (7, "C")]O(n+m)I. Union with a combining function. The implementation uses the efficient  hedge-union algorithm. zunionWith (++) (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "aA"), (7, "C")]O(n+m)J. Union with a combining function. The implementation uses the efficient  hedge-union algorithm. let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value unionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "5:a|A"), (7, "C")]O(n+m). Difference of two maps. Return elements of the first map not existing in the second map. The implementation uses an efficient hedge algorithm comparable with  hedge-union. ]difference (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 3 "b"O(n+m). Difference with a combining function. When two equal keys are encountered, the combining function is applied to the values of these keys. If it returns D, the element is discarded (proper set difference). If it returns ( y+), the element is updated with a new value y(. The implementation uses an efficient hedge algorithm comparable with  hedge-union. let f al ar = if al == "b" then Just (al ++ ":" ++ ar) else Nothing differenceWith f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (3, "B"), (7, "C")]) == singleton 3 "b:B"O(n+m). Difference with a combining function. When two equal keys are encountered, the combining function is applied to the key and both values. If it returns D, the element is discarded (proper set difference). If it returns ( y+), the element is updated with a new value y(. The implementation uses an efficient hedge algorithm comparable with  hedge-union. let f k al ar = if al == "b" then Just ((show k) ++ ":" ++ al ++ "|" ++ ar) else Nothing differenceWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (3, "B"), (10, "C")]) == singleton 3 "3:b|B"O(n+m)`. Intersection of two maps. Return data in the first map for the keys existing in both maps. ( m1 m2 ==   m1 m2)). The implementation uses an efficient hedge algorithm comparable with  hedge-union. _intersection (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "a"O(n+m)Q. Intersection with a combining function. The implementation uses an efficient hedge algorithm comparable with  hedge-union. iintersectionWith (++) (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "aA"O(n+m)Q. Intersection with a combining function. The implementation uses an efficient hedge algorithm comparable with  hedge-union. let f k al ar = (show k) ++ ":" ++ al ++ "|" ++ ar intersectionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "5:a|A"O(n+m)T. A high-performance universal combining function. This function is used to define , , , , , ; and can be used to define other custom combine functions.6Please make sure you know what is going on when using f, otherwise you can be surprised by unexpected code growth or even corruption of the data structure.When U is given three arguments, it is inlined to the call site. You should therefore use P only to define your custom combining functions. For example, you could define ,  and  as myUnionWithKey f m1 m2 = mergeWithKey (\k x1 x2 -> Just (f k x1 x2)) id id m1 m2 myDifferenceWithKey f m1 m2 = mergeWithKey f id (const empty) m1 m2 myIntersectionWithKey f m1 m2 = mergeWithKey (\k x1 x2 -> Just (f k x1 x2)) (const empty) (const empty) m1 m2 When calling  combine only1 only2, a function combining two s is created, such thatXif a key is present in both maps, it is passed with both corresponding values to the combinet function. Depending on the result, the key is either present in the result with specified value, or is left out;>a nonempty subtree present only in the first map is passed to only1* and the output is added to the result;?a nonempty subtree present only in the second map is passed to only2* and the output is added to the result.The only1 and only2 methods Mmust return a map with a subset (possibly empty) of the keys of the given mapC. The values can be modified arbitrarily. Most common variants of only1 and only2 are  and  , but for example  f or  f could be used for any f.O(n+m) . This function is defined as ( =  (==)).O(n+m). The expression ( f t1 t2 ) returns  if all keys in t1 are in tree t2 , and when f returns [ when applied to their respective values. For example, the following expressions are all : isSubmapOfBy (==) (fromList [('a',1)]) (fromList [('a',1),('b',2)]) isSubmapOfBy (<=) (fromList [('a',1)]) (fromList [('a',1),('b',2)]) isSubmapOfBy (==) (fromList [('a',1),('b',2)]) (fromList [('a',1),('b',2)])But the following are all : isSubmapOfBy (==) (fromList [('a',2)]) (fromList [('a',1),('b',2)]) isSubmapOfBy (<) (fromList [('a',1)]) (fromList [('a',1),('b',2)]) isSubmapOfBy (==) (fromList [('a',1),('b',2)]) (fromList [('a',1)])O(n+m)F. Is this a proper submap? (ie. a submap but not equal). Defined as ( =  (==)).O(n+m)J. Is this a proper submap? (ie. a submap but not equal). The expression ( f m1 m2 ) returns  when m1 and m2 are not equal, all keys in m1 are in m2 , and when f returns [ when applied to their respective values. For example, the following expressions are all : isProperSubmapOfBy (==) (fromList [(1,1)]) (fromList [(1,1),(2,2)]) isProperSubmapOfBy (<=) (fromList [(1,1)]) (fromList [(1,1),(2,2)])But the following are all : isProperSubmapOfBy (==) (fromList [(1,1),(2,2)]) (fromList [(1,1),(2,2)]) isProperSubmapOfBy (==) (fromList [(1,1),(2,2)]) (fromList [(1,1)]) isProperSubmapOfBy (<) (fromList [(1,1)]) (fromList [(1,1),(2,2)])O(n)/. Filter all values that satisfy the predicate. filter (> "a") (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" filter (> "x") (fromList [(5,"a"), (3,"b")]) == empty filter (< "a") (fromList [(5,"a"), (3,"b")]) == emptyO(n)4. Filter all keys/values that satisfy the predicate. NfilterWithKey (\k _ -> k > 4) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(n). Partition the map according to a predicate. The first map contains all elements that satisfy the predicate, the second all elements that fail the predicate. See also  .  partition (> "a") (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", singleton 5 "a") partition (< "x") (fromList [(5,"a"), (3,"b")]) == (fromList [(3, "b"), (5, "a")], empty) partition (> "x") (fromList [(5,"a"), (3,"b")]) == (empty, fromList [(3, "b"), (5, "a")])O(n). Partition the map according to a predicate. The first map contains all elements that satisfy the predicate, the second all elements that fail the predicate. See also  . 9partitionWithKey (\ k _ -> k > 3) (fromList [(5,"a"), (3,"b")]) == (singleton 5 "a", singleton 3 "b") partitionWithKey (\ k _ -> k < 7) (fromList [(5,"a"), (3,"b")]) == (fromList [(3, "b"), (5, "a")], empty) partitionWithKey (\ k _ -> k > 7) (fromList [(5,"a"), (3,"b")]) == (empty, fromList [(3, "b"), (5, "a")])O(n). Map values and collect the  results. tlet f x = if x == "a" then Just "new a" else Nothing mapMaybe f (fromList [(5,"a"), (3,"b")]) == singleton 5 "new a"O(n)". Map keys/values and collect the  results. let f k _ = if k < 5 then Just ("key : " ++ (show k)) else Nothing mapMaybeWithKey f (fromList [(5,"a"), (3,"b")]) == singleton 3 "key : 3"O(n). Map values and separate the  and  results. 5let f a = if a < "c" then Left a else Right a mapEither f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (fromList [(3,"b"), (5,"a")], fromList [(1,"x"), (7,"z")]) mapEither (\ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (empty, fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])O(n)#. Map keys/values and separate the  and  results. Olet f k a = if k < 5 then Left (k * 2) else Right (a ++ a) mapEitherWithKey f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (fromList [(1,2), (3,6)], fromList [(5,"aa"), (7,"zz")]) mapEitherWithKey (\_ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (empty, fromList [(1,"x"), (3,"b"), (5,"a"), (7,"z")])O(n),. Map a function over all values in the map. Mmap (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]O(n),. Map a function over all values in the map. tlet f key x = (show key) ++ ":" ++ x mapWithKey f (fromList [(5,"a"), (3,"b")]) == fromList [(3, "3:b"), (5, "5:a")]O(n).  f m ==   $  ((k, v) -> (,) k  $ f k v) ( m)* That is, behaves exactly like a regular Y except that the traversing function also has access to the key associated with a value. traverseWithKey (\k v -> if odd k then Just (succ v) else Nothing) (fromList [(1, 'a'), (5, 'e')]) == Just (fromList [(1, 'b'), (5, 'f')]) traverseWithKey (\k v -> if odd k then Just (succ v) else Nothing) (fromList [(2, 'c')]) == NothingO(n). The function N threads an accumulating argument through the map in ascending order of keys. let f a b = (a ++ b, b ++ "X") mapAccum f "Everything: " (fromList [(5,"a"), (3,"b")]) == ("Everything: ba", fromList [(3, "bX"), (5, "aX")])O(n). The function N threads an accumulating argument through the map in ascending order of keys. let f a k b = (a ++ " " ++ (show k) ++ "-" ++ b, b ++ "X") mapAccumWithKey f "Everything:" (fromList [(5,"a"), (3,"b")]) == ("Everything: 3-b 5-a", fromList [(3, "bX"), (5, "aX")])O(n). The function N threads an accumulating argument through the map in ascending order of keys.O(n). The function  mapAccumRO threads an accumulating argument through the map in descending order of keys. O(n*log n).  f s! is the map obtained by applying f to each key of s.)The size of the result may be smaller if f maps two or more distinct keys to the same new key. In this case the value at the greatest of the original keys is retained. mapKeys (+ 1) (fromList [(5,"a"), (3,"b")]) == fromList [(4, "b"), (6, "a")] mapKeys (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "c" mapKeys (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "c" O(n*log n).  c f s! is the map obtained by applying f to each key of s.)The size of the result may be smaller if fr maps two or more distinct keys to the same new key. In this case the associated values will be combined using c. mapKeysWith (++) (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "cdab" mapKeysWith (++) (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "cdab"O(n).  f s ==  f s, but works only when f2 is strictly monotonic. That is, for any values x and y, if x < y then f x < f y.  The precondition is not checked. Semi-formally, we have: ~and [x < y ==> f x < f y | x <- ls, y <- ls] ==> mapKeysMonotonic f s == mapKeys f s where ls = keys sThis means that fd maps distinct original keys to distinct resulting keys. This function has better performance than . mapKeysMonotonic (\ k -> k * 2) (fromList [(5,"a"), (3,"b")]) == fromList [(6, "b"), (10, "a")] valid (mapKeysMonotonic (\ k -> k * 2) (fromList [(5,"a"), (3,"b")])) == True valid (mapKeysMonotonic (\ _ -> 1) (fromList [(5,"a"), (3,"b")])) == FalseO(n)[. Fold the values in the map using the given right-associative binary operator, such that  f z ==  f z . . For example, elems map = foldr (:) [] map Mlet f a len = len + (length a) foldr f 0 (fromList [(5,"a"), (3,"bbb")]) == 4O(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)Z. Fold the values in the map using the given left-associative binary operator, such that  f z ==  f z . . For example, %elems = reverse . foldl (flip (:)) [] Mlet f len a = len + (length a) foldl f 0 (fromList [(5,"a"), (3,"bbb")]) == 4O(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)e. Fold the keys and values in the map using the given right-associative binary operator, such that  f z ==  ( f) z . . For example, 0keys map = foldrWithKey (\k x ks -> k:ks) [] map let f k a result = result ++ "(" ++ (show k) ++ ":" ++ a ++ ")" foldrWithKey f "Map: " (fromList [(5,"a"), (3,"b")]) == "Map: (5:a)(3:b)"O(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)d. Fold the keys and values in the map using the given left-associative binary operator, such that  f z ==  (\z' (kx, x) -> f z' kx x) z . . For example, 2keys = reverse . foldlWithKey (\ks k x -> k:ks) [] let f result k a = result ++ "(" ++ (show k) ++ ":" ++ a ++ ")" foldlWithKey f "Map: " (fromList [(5,"a"), (3,"b")]) == "Map: (3:b)(5:a)"O(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)G. Fold the keys and values in the map using the given monoid, such that  f =  .  f*This can be an asymptotically faster than  or  for some monoids.O(n)`. Return all elements of the map in the ascending order of their keys. Subject to list fusion. Belems (fromList [(5,"a"), (3,"b")]) == ["b","a"] elems empty == []O(n)I. Return all keys of the map in ascending order. Subject to list fusion. <keys (fromList [(5,"a"), (3,"b")]) == [3,5] keys empty == []O(n). An alias for X. Return all key/value pairs in the map in ascending key order. Subject to list fusion. Massocs (fromList [(5,"a"), (3,"b")]) == [(3,"b"), (5,"a")] assocs empty == []O(n)!. The set of all keys of the map. `keysSet (fromList [(5,"a"), (3,"b")]) == Data.Set.fromList [3,5] keysSet empty == Data.Set.emptyO(n)W. Build a map from a set of keys and a function which for each key computes its value. fromSet (\k -> replicate k 'a') (Data.Set.fromList [3, 5]) == fromList [(5,"aaaaa"), (3,"aaa")] fromSet undefined Data.Set.empty == empty O(n*log n)7. Build a map from a list of key/value pairs. See also f. If the list contains more than one value for the same key, the last value for the key is retained.hIf the keys of the list are ordered, linear-time implementation is used, with the performance equal to  . fromList [] == empty fromList [(5,"a"), (3,"b"), (5, "c")] == fromList [(5,"c"), (3,"b")] fromList [(5,"c"), (3,"b"), (5, "a")] == fromList [(5,"a"), (3,"b")] O(n*log n)Q. Build a map from a list of key/value pairs with a combining function. See also . fromListWith (++) [(5,"a"), (5,"b"), (3,"b"), (3,"a"), (5,"a")] == fromList [(3, "ab"), (5, "aba")] fromListWith (++) [] == empty O(n*log n)Q. Build a map from a list of key/value pairs with a combining function. See also . let f k a1 a2 = (show k) ++ a1 ++ a2 fromListWithKey f [(5,"a"), (5,"b"), (3,"b"), (3,"a"), (5,"a")] == fromList [(3, "3ab"), (5, "5a5ba")] fromListWithKey f [] == emptyO(n)G. Convert the map to a list of key/value pairs. Subject to list fusion. MtoList (fromList [(5,"a"), (3,"b")]) == [(3,"b"), (5,"a")] toList empty == []O(n)n. Convert the map to a list of key/value pairs where the keys are in ascending order. Subject to list fusion. =toAscList (fromList [(5,"a"), (3,"b")]) == [(3,"b"), (5,"a")]O(n)o. Convert the map to a list of key/value pairs where the keys are in descending order. Subject to list fusion. >toDescList (fromList [(5,"a"), (3,"b")]) == [(5,"a"), (3,"b")]O(n)6. Build a map from an ascending list in linear time. :The precondition (input list is ascending) is not checked. fromAscList [(3,"b"), (5,"a")] == fromList [(3, "b"), (5, "a")] fromAscList [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "b")] valid (fromAscList [(3,"b"), (5,"a"), (5,"b")]) == True valid (fromAscList [(5,"a"), (3,"b"), (5,"b")]) == FalseO(n)_. Build a map from an ascending list in linear time with a combining function for equal keys. :The precondition (input list is ascending) is not checked. fromAscListWith (++) [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "ba")] valid (fromAscListWith (++) [(3,"b"), (5,"a"), (5,"b")]) == True valid (fromAscListWith (++) [(5,"a"), (3,"b"), (5,"b")]) == FalseO(n)`. Build a map from an ascending list in linear time with a combining function for equal keys. :The precondition (input list is ascending) is not checked. !let f k a1 a2 = (show k) ++ ":" ++ a1 ++ a2 fromAscListWithKey f [(3,"b"), (5,"a"), (5,"b"), (5,"b")] == fromList [(3, "b"), (5, "5:b5:ba")] valid (fromAscListWithKey f [(3,"b"), (5,"a"), (5,"b"), (5,"b")]) == True valid (fromAscListWithKey f [(5,"a"), (3,"b"), (5,"b"), (5,"b")]) == False O(n)K. Build a map from an ascending list of distinct elements in linear time.  The precondition is not checked. fromDistinctAscList [(3,"b"), (5,"a")] == fromList [(3, "b"), (5, "a")] valid (fromDistinctAscList [(3,"b"), (5,"a")]) == True valid (fromDistinctAscList [(3,"b"), (5,"a"), (5,"b")]) == False O(log n). The expression (  k map ) is a pair  (map1,map2) where the keys in map1 are smaller than k and the keys in map2 larger than k. Any key equal to k is found in neither map1 nor map2. ksplit 2 (fromList [(5,"a"), (3,"b")]) == (empty, fromList [(3,"b"), (5,"a")]) split 3 (fromList [(5,"a"), (3,"b")]) == (empty, singleton 5 "a") split 4 (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", singleton 5 "a") split 5 (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", empty) split 6 (fromList [(5,"a"), (3,"b")]) == (fromList [(3,"b"), (5,"a")], empty) O(log n). The expression (  k map) splits a map just like   but also returns  k map. splitLookup 2 (fromList [(5,"a"), (3,"b")]) == (empty, Nothing, fromList [(3,"b"), (5,"a")]) splitLookup 3 (fromList [(5,"a"), (3,"b")]) == (empty, Just "b", singleton 5 "a") splitLookup 4 (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", Nothing, singleton 5 "a") splitLookup 5 (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", Just "a", empty) splitLookup 6 (fromList [(5,"a"), (3,"b")]) == (fromList [(3,"b"), (5,"a")], Nothing, empty) O(log n)&. Delete and find the minimal element. deleteFindMin (fromList [(5,"a"), (3,"b"), (10,"c")]) == ((3,"b"), fromList[(5,"a"), (10,"c")]) deleteFindMin Error: can not return the minimal element of an empty map O(log n)&. Delete and find the maximal element. deleteFindMax (fromList [(5,"a"), (3,"b"), (10,"c")]) == ((10,"c"), fromList [(3,"b"), (5,"a")]) deleteFindMax empty Error: can not return the maximal element of an empty mapO(n)a. Show the tree that implements the map. The tree is shown in a compressed, hanging format. See .O(n). The expression ( showelem hang wide mapH) shows the tree that implements the map. Elements are shown using the showElem function. If hang is , a hanging6 tree is shown otherwise a rotated tree is shown. If wide is !, an extra wide version is shown.  Map> let t = fromDistinctAscList [(x,()) | x <- [1..5]] Map> putStrLn $ showTreeWith (\k x -> show (k,x)) True False t (4,()) +--(2,()) | +--(1,()) | +--(3,()) +--(5,()) Map> putStrLn $ showTreeWith (\k x -> show (k,x)) True True t (4,()) | +--(2,()) | | | +--(1,()) | | | +--(3,()) | +--(5,()) Map> putStrLn $ showTreeWith (\k x -> show (k,x)) False True t +--(5,()) | (4,()) | | +--(3,()) | | +--(2,()) | +--(1,())O(n).. Test if the internal map structure is valid. ^valid (fromAscList [(3,"b"), (5,"a")]) == True valid (fromAscList [(5,"a"), (3,"b")]) == FalseExported only for Debug.QuickCheckO(1). Decompose a map into pieces based on the structure of the underlying tree. This function is useful for consuming a map in parallel.No guarantee is made as to the sizes of the pieces; an internal, but deterministic process determines this. However, it is guaranteed that the pieces returned will be in ascending order (all elements in the first submap less than all elements in the second, and so on). Examples: splitRoot (fromList (zip [1..6] ['a'..])) == [fromList [(1,'a'),(2,'b'),(3,'c')],fromList [(4,'d')],fromList [(5,'e'),(6,'f')]] splitRoot empty == []Note that the current implementation does not return more than three submaps, but you should not depend on this behaviour because it can change in the future without notice. !"#$%&'()*+, -./0  12345  6789:;<=>?@ABCDEFGHIJKLMNO!" -./0  1245  689:; !"#$%&'()*+, -./0  12345  6789:;<=>?@ABCDEFGHIJKLMNO @(c) Daan Leijen 2002 (c) Andriy Palamarchuk 2008 BSD-stylelibraries@haskell.org provisionalportableSafel     l     @(c) Daan Leijen 2002 (c) Andriy Palamarchuk 2008 BSD-stylelibraries@haskell.org provisionalportable Trustworthy,O(log n). The expression ( def k map) returns the value at key k or returns default value def! when the key is not in the map. ufindWithDefault 'x' 1 (fromList [(5,'a'), (3,'b')]) == 'x' findWithDefault 'x' 5 (fromList [(5,'a'), (3,'b')]) == 'a'O(1). A map with a single element. Isingleton 1 'a' == fromList [(1, 'a')] size (singleton 1 'a') == 1O(log n). Insert a new key and value in the map. If the key is already present in the map, the associated value is replaced with the supplied value.  is equivalent to  . insert 5 'x' (fromList [(5,'a'), (3,'b')]) == fromList [(3, 'b'), (5, 'x')] insert 7 'x' (fromList [(5,'a'), (3,'b')]) == fromList [(3, 'b'), (5, 'a'), (7, 'x')] insert 5 'x' empty == singleton 5 'x'O(log n)>. Insert with a function, combining new value and old value.  f key value mp) will insert the pair (key, value) into mp^ if key does not exist in the map. If the key does exist, the function will insert the pair (key, f new_value old_value). insertWith (++) 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "xxxa")] insertWith (++) 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")] insertWith (++) 5 "xxx" empty == singleton 5 "xxx"O(log n)C. Insert with a function, combining key, new value and old value.  f key value mp) will insert the pair (key, value) into mp^ if key does not exist in the map. If the key does exist, the function will insert the pair (key,f key new_value old_value);. Note that the key passed to f is the same key passed to . ]let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")] insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")] insertWithKey f 5 "xxx" empty == singleton 5 "xxx"O(log n)G. Combines insert operation with old value retrieval. The expression ( f k x map2) is a pair where the first element is equal to ( k map$) and the second element equal to ( f k x map). let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value insertLookupWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "5:xxx|a")]) insertLookupWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a"), (7, "xxx")]) insertLookupWithKey f 5 "xxx" empty == (Nothing, singleton 5 "xxx")This is how to define  insertLookup using insertLookupWithKey: let insertLookup kx x t = insertLookupWithKey (\_ a _ -> a) kx x t insertLookup 5 "x" (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "x")]) insertLookup 7 "x" (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a"), (7, "x")])O(log n). Update a value at a specific key with the result of the provided function. When the key is not a member of the map, the original map is returned. adjust ("new " ++) 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] adjust ("new " ++) 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] adjust ("new " ++) 7 empty == emptyO(log n)k. Adjust a value at a specific key. When the key is not a member of the map, the original map is returned.  let f key x = (show key) ++ ":new " ++ x adjustWithKey f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:new a")] adjustWithKey f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] adjustWithKey f 7 empty == emptyO(log n). The expression ( f k map) updates the value x at k (if it is in the map). If (f x) is %, the element is deleted. If it is ( y ), the key k is bound to the new value y. let f x = if x == "a" then Just "new a" else Nothing update f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] update f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] update f 3 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(log n). The expression ( f k map) updates the value x at k (if it is in the map). If (f k x) is %, the element is deleted. If it is ( y ), the key k is bound to the new value y. 0let f k x = if x == "a" then Just ((show k) ++ ":new a") else Nothing updateWithKey f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:new a")] updateWithKey f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] updateWithKey f 3 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(log n). Lookup and update. See also u. The function returns changed value, if it is updated. Returns the original key value if the map entry is deleted. llet f k x = if x == "a" then Just ((show k) ++ ":new a") else Nothing updateLookupWithKey f 5 (fromList [(5,"a"), (3,"b")]) == (Just "5:new a", fromList [(3, "b"), (5, "5:new a")]) updateLookupWithKey f 7 (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a")]) updateLookupWithKey f 3 (fromList [(5,"a"), (3,"b")]) == (Just "b", singleton 5 "a")O(log n). The expression ( f k map) alters the value x at k, or absence thereof. 7 can be used to insert, delete, or update a value in a . In short :  k ( f k m) = f ( k m). Elet f _ = Nothing alter f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] alter f 5 (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" let f _ = Just "c" alter f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "c")] alter f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "c")]O(log n). Update the element at index. Calls  when an invalid index is used. updateAt (\ _ _ -> Just "x") 0 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "x"), (5, "a")] updateAt (\ _ _ -> Just "x") 1 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "x")] updateAt (\ _ _ -> Just "x") 2 (fromList [(5,"a"), (3,"b")]) Error: index out of range updateAt (\ _ _ -> Just "x") (-1) (fromList [(5,"a"), (3,"b")]) Error: index out of range updateAt (\_ _ -> Nothing) 0 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" updateAt (\_ _ -> Nothing) 1 (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" updateAt (\_ _ -> Nothing) 2 (fromList [(5,"a"), (3,"b")]) Error: index out of range updateAt (\_ _ -> Nothing) (-1) (fromList [(5,"a"), (3,"b")]) Error: index out of rangeO(log n)&. Update the value at the minimal key. updateMin (\ a -> Just ("X" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3, "Xb"), (5, "a")] updateMin (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" O(log n)&. Update the value at the maximal key. updateMax (\ a -> Just ("X" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "Xa")] updateMax (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 3 "b"!O(log n)&. Update the value at the minimal key. updateMinWithKey (\ k a -> Just ((show k) ++ ":" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3,"3:b"), (5,"a")] updateMinWithKey (\ _ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a""O(log n)&. Update the value at the maximal key. updateMaxWithKey (\ k a -> Just ((show k) ++ ":" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3,"b"), (5,"5:a")] updateMaxWithKey (\ _ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 3 "b"#=The union of a list of maps, with a combining operation: (# f ==  ($ f) ). unionsWith (++) [(fromList [(5, "a"), (3, "b")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "A3"), (3, "B3")])] == fromList [(3, "bB3"), (5, "aAA3"), (7, "C")]$O(n+m)I. Union with a combining function. The implementation uses the efficient  hedge-union algorithm. zunionWith (++) (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "aA"), (7, "C")]%O(n+m)J. Union with a combining function. The implementation uses the efficient  hedge-union algorithm. let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value unionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "5:a|A"), (7, "C")]&O(n+m). Difference with a combining function. When two equal keys are encountered, the combining function is applied to the values of these keys. If it returns D, the element is discarded (proper set difference). If it returns ( y+), the element is updated with a new value y(. The implementation uses an efficient hedge algorithm comparable with  hedge-union. let f al ar = if al == "b" then Just (al ++ ":" ++ ar) else Nothing differenceWith f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (3, "B"), (7, "C")]) == singleton 3 "b:B"'O(n+m). Difference with a combining function. When two equal keys are encountered, the combining function is applied to the key and both values. If it returns D, the element is discarded (proper set difference). If it returns ( y+), the element is updated with a new value y(. The implementation uses an efficient hedge algorithm comparable with  hedge-union. let f k al ar = if al == "b" then Just ((show k) ++ ":" ++ al ++ "|" ++ ar) else Nothing differenceWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (3, "B"), (10, "C")]) == singleton 3 "3:b|B"(O(n+m)Q. Intersection with a combining function. The implementation uses an efficient hedge algorithm comparable with  hedge-union. iintersectionWith (++) (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "aA")O(n+m)Q. Intersection with a combining function. The implementation uses an efficient hedge algorithm comparable with  hedge-union. let f k al ar = (show k) ++ ":" ++ al ++ "|" ++ ar intersectionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "5:a|A"*O(n+m)T. A high-performance universal combining function. This function is used to define $, %, &, ', (, ); and can be used to define other custom combine functions.6Please make sure you know what is going on when using *f, otherwise you can be surprised by unexpected code growth or even corruption of the data structure.When *U is given three arguments, it is inlined to the call site. You should therefore use *P only to define your custom combining functions. For example, you could define %, ' and ) as myUnionWithKey f m1 m2 = mergeWithKey (\k x1 x2 -> Just (f k x1 x2)) id id m1 m2 myDifferenceWithKey f m1 m2 = mergeWithKey f id (const empty) m1 m2 myIntersectionWithKey f m1 m2 = mergeWithKey (\k x1 x2 -> Just (f k x1 x2)) (const empty) (const empty) m1 m2 When calling * combine only1 only2, a function combining two IntMaps is created, such thatXif a key is present in both maps, it is passed with both corresponding values to the combinet function. Depending on the result, the key is either present in the result with specified value, or is left out;>a nonempty subtree present only in the first map is passed to only1* and the output is added to the result;?a nonempty subtree present only in the second map is passed to only2* and the output is added to the result.The only1 and only2 methods Mmust return a map with a subset (possibly empty) of the keys of the given mapC. The values can be modified arbitrarily. Most common variants of only1 and only2 are  and  , but for example / f or  f could be used for any f.+O(n). Map values and collect the  results. tlet f x = if x == "a" then Just "new a" else Nothing mapMaybe f (fromList [(5,"a"), (3,"b")]) == singleton 5 "new a",O(n)". Map keys/values and collect the  results. let f k _ = if k < 5 then Just ("key : " ++ (show k)) else Nothing mapMaybeWithKey f (fromList [(5,"a"), (3,"b")]) == singleton 3 "key : 3"-O(n). Map values and separate the  and  results. 5let f a = if a < "c" then Left a else Right a mapEither f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (fromList [(3,"b"), (5,"a")], fromList [(1,"x"), (7,"z")]) mapEither (\ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (empty, fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]).O(n)#. Map keys/values and separate the  and  results. Olet f k a = if k < 5 then Left (k * 2) else Right (a ++ a) mapEitherWithKey f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (fromList [(1,2), (3,6)], fromList [(5,"aa"), (7,"zz")]) mapEitherWithKey (\_ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (empty, fromList [(1,"x"), (3,"b"), (5,"a"), (7,"z")])/O(n),. Map a function over all values in the map. Mmap (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]0O(n),. Map a function over all values in the map. tlet f key x = (show key) ++ ":" ++ x mapWithKey f (fromList [(5,"a"), (3,"b")]) == fromList [(3, "3:b"), (5, "5:a")]1O(n). The function 1N threads an accumulating argument through the map in ascending order of keys. let f a b = (a ++ b, b ++ "X") mapAccum f "Everything: " (fromList [(5,"a"), (3,"b")]) == ("Everything: ba", fromList [(3, "bX"), (5, "aX")])2O(n). The function 2N threads an accumulating argument through the map in ascending order of keys. let f a k b = (a ++ " " ++ (show k) ++ "-" ++ b, b ++ "X") mapAccumWithKey f "Everything:" (fromList [(5,"a"), (3,"b")]) == ("Everything: 3-b 5-a", fromList [(3, "bX"), (5, "aX")])PO(n). The function PN threads an accumulating argument through the map in ascending order of keys.3O(n). The function  mapAccumRO threads an accumulating argument through the map in descending order of keys.4 O(n*log n). 4 c f s! is the map obtained by applying f to each key of s.)The size of the result may be smaller if fr maps two or more distinct keys to the same new key. In this case the associated values will be combined using c. mapKeysWith (++) (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "cdab" mapKeysWith (++) (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "cdab"5O(n)W. Build a map from a set of keys and a function which for each key computes its value. fromSet (\k -> replicate k 'a') (Data.Set.fromList [3, 5]) == fromList [(5,"aaaaa"), (3,"aaa")] fromSet undefined Data.Set.empty == empty6 O(n*log n)7. Build a map from a list of key/value pairs. See also 9f. If the list contains more than one value for the same key, the last value for the key is retained.hIf the keys of the list are ordered, linear-time implementation is used, with the performance equal to <. fromList [] == empty fromList [(5,"a"), (3,"b"), (5, "c")] == fromList [(5,"c"), (3,"b")] fromList [(5,"c"), (3,"b"), (5, "a")] == fromList [(5,"a"), (3,"b")]7 O(n*log n)Q. Build a map from a list of key/value pairs with a combining function. See also :. fromListWith (++) [(5,"a"), (5,"b"), (3,"b"), (3,"a"), (5,"a")] == fromList [(3, "ab"), (5, "aba")] fromListWith (++) [] == empty8 O(n*log n)Q. Build a map from a list of key/value pairs with a combining function. See also ;. let f k a1 a2 = (show k) ++ a1 ++ a2 fromListWithKey f [(5,"a"), (5,"b"), (3,"b"), (3,"a"), (5,"a")] == fromList [(3, "3ab"), (5, "5a5ba")] fromListWithKey f [] == empty9O(n)6. Build a map from an ascending list in linear time. :The precondition (input list is ascending) is not checked. fromAscList [(3,"b"), (5,"a")] == fromList [(3, "b"), (5, "a")] fromAscList [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "b")] valid (fromAscList [(3,"b"), (5,"a"), (5,"b")]) == True valid (fromAscList [(5,"a"), (3,"b"), (5,"b")]) == False:O(n)_. Build a map from an ascending list in linear time with a combining function for equal keys. :The precondition (input list is ascending) is not checked. fromAscListWith (++) [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "ba")] valid (fromAscListWith (++) [(3,"b"), (5,"a"), (5,"b")]) == True valid (fromAscListWith (++) [(5,"a"), (3,"b"), (5,"b")]) == False;O(n)`. Build a map from an ascending list in linear time with a combining function for equal keys. :The precondition (input list is ascending) is not checked. !let f k a1 a2 = (show k) ++ ":" ++ a1 ++ a2 fromAscListWithKey f [(3,"b"), (5,"a"), (5,"b"), (5,"b")] == fromList [(3, "b"), (5, "5:b5:ba")] valid (fromAscListWithKey f [(3,"b"), (5,"a"), (5,"b"), (5,"b")]) == True valid (fromAscListWithKey f [(5,"a"), (3,"b"), (5,"b"), (5,"b")]) == False<O(n)K. Build a map from an ascending list of distinct elements in linear time.  The precondition is not checked. fromDistinctAscList [(3,"b"), (5,"a")] == fromList [(3, "b"), (5, "a")] valid (fromDistinctAscList [(3,"b"), (5,"a")]) == True valid (fromDistinctAscList [(3,"b"), (5,"a"), (5,"b")]) == False, !"#$%&'()*+,-./012P3456789:;<l     !"#$%&'()*+,-./0123456789:; Deprecated.! As of version 0.5, replaced by .O(log n) . Same as K, but the value being inserted to the map is evaluated to WHNF beforehand.? Deprecated.! As of version 0.5, replaced by .O(log n) . Same as K, but the value being inserted to the map is evaluated to WHNF beforehand.@ Deprecated. As of version 0.5, replaced by .O(n)s. Fold the values in the map using the given right-associative binary operator. This function is an equivalent of ( and is present for compatibility only.A Deprecated. As of version 0.4, replaced by .O(n)|. Fold the keys and values in the map using the given right-associative binary operator. This function is an equivalent of ( and is present for compatibility only.=>?@Aq     =>?@A=>?@A=>?@A(c) Daan Leijen 2002 BSD-stylelibraries@haskell.org provisionalportableSafe6pqrstuvwxyz{|}~6pqrstuvwxy~z{|}:(c) Clark Gaebel 2012 (c) Johan Tibel 2012 BSD-stylelibraries@haskell.org provisionalportable Trustworthy<Q0Return a word where only the highest bit is set.QRSQRSQRS>(c) Daan Leijen 2002 (c) Joachim Breitner 2011 BSD-stylelibraries@haskell.org provisionalportable Trustworthy *+<>L0CA set of integers.DO(n+m). See S.EO(1). Is the set empty?FO(n). Cardinality of the set.G O(min(n,W))#. Is the value a member of the set?H O(min(n,W)) . Is the element not in the set?IO(log n)2. Find largest element smaller than the given one. NlookupLT 3 (fromList [3, 5]) == Nothing lookupLT 5 (fromList [3, 5]) == Just 3JO(log n)3. Find smallest element greater than the given one. NlookupGT 4 (fromList [3, 5]) == Just 5 lookupGT 5 (fromList [3, 5]) == NothingKO(log n)9. Find largest element smaller or equal to the given one. ulookupLE 2 (fromList [3, 5]) == Nothing lookupLE 4 (fromList [3, 5]) == Just 3 lookupLE 5 (fromList [3, 5]) == Just 5LO(log n):. Find smallest element greater or equal to the given one. ulookupGE 3 (fromList [3, 5]) == Just 3 lookupGE 4 (fromList [3, 5]) == Just 5 lookupGE 6 (fromList [3, 5]) == NothingMO(1). The empty set.NO(1). A set of one element.O O(min(n,W))G. Add a value to the set. There is no left- or right bias for IntSets.P O(min(n,W))V. Delete a value in the set. Returns the original set when the value was not present.QThe union of a list of sets.RO(n+m). The union of two sets.SO(n+m). Difference between two sets.TO(n+m). The intersection of two sets.UO(n+m)8. Is this a proper subset? (ie. a subset but not equal).VO(n+m). Is this a subset? (s1 V s2) tells whether s1 is a subset of s2.WO(n)2. Filter all elements that satisfy some predicate.XO(n)0. partition the set according to some predicate.Y O(min(n,W)). The expression (Y x set ) is a pair  (set1,set2) where set1 comprises the elements of set less than x and set2 comprises the elements of set greater than x. =split 3 (fromList [1..5]) == (fromList [1,2], fromList [4,5])Z O(min(n,W)) . Performs a YK but also returns whether the pivot element was found in the original set.[ O(min(n,W))R. Retrieves the maximal key of the set, and the set stripped of that element, or  if passed an empty set.\ O(min(n,W))R. Retrieves the minimal key of the set, and the set stripped of that element, or  if passed an empty set.] O(min(n,W))&. Delete and find the minimal element. 0deleteFindMin set = (findMin set, deleteMin set)^ O(min(n,W))&. Delete and find the maximal element. 0deleteFindMax set = (findMax set, deleteMax set)_ O(min(n,W))!. The minimal element of the set.` O(min(n,W)). The maximal element of a set.a O(min(n,W))G. Delete the minimal element. Returns an empty set if the set is empty.=Note that this is a change of behaviour for consistency with 0  versions prior to 0.5 threw an error if the C was already empty.b O(min(n,W))G. Delete the maximal element. Returns an empty set if the set is empty.=Note that this is a change of behaviour for consistency with 0  versions prior to 0.5 threw an error if the C was already empty.c O(n*min(n,W)). c f s! is the set obtained by applying f to each element of s.KIt's worth noting that the size of the result may be smaller if, for some (x,y), x /= y && f x == f ydO(n)u. Fold the elements in the set using the given right-associative binary operator. This function is an equivalent of e( and is present for compatibility only.CPlease note that fold will be deprecated in the future and removed.eO(n)]. Fold the elements in the set using the given right-associative binary operator, such that e f z ==  f z . k. For example,  toAscList set = foldr (:) [] setfO(n). A strict version of e. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.gO(n)\. Fold the elements in the set using the given left-associative binary operator, such that g f z ==  f z . k. For example, (toDescList set = foldl (flip (:)) [] sethO(n). A strict version of g. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.iO(n). An alias of kD. The elements of a set in ascending order. Subject to list fusion.jO(n)@. Convert the set to a list of elements. Subject to list fusion.kO(n)L. Convert the set to an ascending list of elements. Subject to list fusion.lO(n)L. Convert the set to a descending list of elements. Subject to list fusion.m O(n*min(n,W))'. Create a set from a list of integers.nO(n)3. Build a set from an ascending list of elements. :The precondition (input list is ascending) is not checked.oO(n)<. Build a set from an ascending list of distinct elements. CThe precondition (input list is strictly ascending) is not checked.pO(n)\. Show the tree that implements the set. The tree is shown in a compressed, hanging format.qO(n). The expression (q hang wide map.) shows the tree that implements the set. If hang is , a hanging6 tree is shown otherwise a rotated tree is shown. If wide is !, an extra wide version is shown.rO(1). Decompose a set into pieces based on the structure of the underlying tree. This function is useful for consuming a set in parallel.No guarantee is made as to the sizes of the pieces; an internal, but deterministic process determines this. However, it is guaranteed that the pieces returned will be in ascending order (all elements in the first submap less than all elements in the second, and so on). Examples: \splitRoot (fromList [1..120]) == [fromList [1..63],fromList [64..120]] splitRoot empty == []-Note that the current implementation does not return more than two subsets, but you should not depend on this behaviour because it can change in the future without notice. Also, the current version does not continue splitting all the way to individual singleton sets -- it stops at some point.tTUVBWXYCZ[\]^_D`aEFGHIJKLbcMNOdPeQRSTUfVWXYZ[\]^_`abcdefghijklghmnoijpqklmnopqrstuvwxyz{|}~r8BCZ[\DEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqxy}roTUVBWXYCZ[\]^_D`aEFGHIJKLbcMNOdPeQRSTUfVWXYZ[\]^_`abcdefghijklghmnoijpqklmnopqrstuvwxyz{|}~rD >(c) Daan Leijen 2002 (c) Joachim Breitner 2011 BSD-stylelibraries@haskell.org provisionalportableSafe1BCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqr1CBDEFGHIJKLVUMNOPRQSTWXYZrcegfhd_`ab]^[\ijmklnopq@(c) Daan Leijen 2002 (c) Andriy Palamarchuk 2008 BSD-stylelibraries@haskell.org provisionalportable Trustworthy *+<>LNgsA map of integers to values a.t O(min(n,W))". Find the value at a key. Calls # when the element can not be found. gfromList [(5,'a'), (3,'b')] ! 1 Error: element not in the map fromList [(5,'a'), (3,'b')] ! 5 == 'a'uSame as .vO(1). Is the map empty? VData.IntMap.null (empty) == True Data.IntMap.null (singleton 1 'a') == FalsewO(n) . Number of elements in the map. size empty == 0 size (singleton 1 'a') == 1 size (fromList([(1,'a'), (2,'c'), (3,'b')])) == 3x O(min(n,W))!. Is the key a member of the map? ^member 5 (fromList [(5,'a'), (3,'b')]) == True member 1 (fromList [(5,'a'), (3,'b')]) == Falsey O(min(n,W))%. Is the key not a member of the map? dnotMember 5 (fromList [(5,'a'), (3,'b')]) == False notMember 1 (fromList [(5,'a'), (3,'b')]) == Truez O(min(n,W))1. Lookup the value at a key in the map. See also .{ O(min(n,W)). The expression ({ def k map) returns the value at key k or returns def, when the key is not an element of the map. ufindWithDefault 'x' 1 (fromList [(5,'a'), (3,'b')]) == 'x' findWithDefault 'x' 5 (fromList [(5,'a'), (3,'b')]) == 'a'|O(log n)^. Find largest key smaller than the given one and return the corresponding (key, value) pair. mlookupLT 3 (fromList [(3,'a'), (5,'b')]) == Nothing lookupLT 4 (fromList [(3,'a'), (5,'b')]) == Just (3, 'a')}O(log n)_. Find smallest key greater than the given one and return the corresponding (key, value) pair. mlookupGT 4 (fromList [(3,'a'), (5,'b')]) == Just (5, 'b') lookupGT 5 (fromList [(3,'a'), (5,'b')]) == Nothing~O(log n)e. Find largest key smaller or equal to the given one and return the corresponding (key, value) pair. lookupLE 2 (fromList [(3,'a'), (5,'b')]) == Nothing lookupLE 4 (fromList [(3,'a'), (5,'b')]) == Just (3, 'a') lookupLE 5 (fromList [(3,'a'), (5,'b')]) == Just (5, 'b')O(log n)f. Find smallest key greater or equal to the given one and return the corresponding (key, value) pair. lookupGE 3 (fromList [(3,'a'), (5,'b')]) == Just (3, 'a') lookupGE 4 (fromList [(3,'a'), (5,'b')]) == Just (5, 'b') lookupGE 6 (fromList [(3,'a'), (5,'b')]) == NothingO(1). The empty map. )empty == fromList [] size empty == 0O(1). A map of one element. Isingleton 1 'a' == fromList [(1, 'a')] size (singleton 1 'a') == 1 O(min(n,W)). Insert a new key/value pair in the map. If the key is already present in the map, the associated value is replaced with the supplied value, i.e.  is equivalent to  . insert 5 'x' (fromList [(5,'a'), (3,'b')]) == fromList [(3, 'b'), (5, 'x')] insert 7 'x' (fromList [(5,'a'), (3,'b')]) == fromList [(3, 'b'), (5, 'a'), (7, 'x')] insert 5 'x' empty == singleton 5 'x' O(min(n,W))%. Insert with a combining function.  f key value mp) will insert the pair (key, value) into mpU if key does not exist in the map. If the key does exist, the function will insert f new_value old_value. insertWith (++) 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "xxxa")] insertWith (++) 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")] insertWith (++) 5 "xxx" empty == singleton 5 "xxx" O(min(n,W))%. Insert with a combining function.  f key value mp) will insert the pair (key, value) into mpU if key does not exist in the map. If the key does exist, the function will insert f key new_value old_value. ]let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")] insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")] insertWithKey f 5 "xxx" empty == singleton 5 "xxx" O(min(n,W)). The expression ( f k x map2) is a pair where the first element is equal to (z k map$) and the second element equal to ( f k x map). let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value insertLookupWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "5:xxx|a")]) insertLookupWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a"), (7, "xxx")]) insertLookupWithKey f 5 "xxx" empty == (Nothing, singleton 5 "xxx")This is how to define  insertLookup using insertLookupWithKey: let insertLookup kx x t = insertLookupWithKey (\_ a _ -> a) kx x t insertLookup 5 "x" (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "x")]) insertLookup 7 "x" (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a"), (7, "x")]) O(min(n,W))r. Delete a key and its value from the map. When the key is not a member of the map, the original map is returned. delete 5 (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" delete 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] delete 5 empty == empty O(min(n,W))k. Adjust a value at a specific key. When the key is not a member of the map, the original map is returned. adjust ("new " ++) 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] adjust ("new " ++) 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] adjust ("new " ++) 7 empty == empty O(min(n,W))k. Adjust a value at a specific key. When the key is not a member of the map, the original map is returned.  let f key x = (show key) ++ ":new " ++ x adjustWithKey f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:new a")] adjustWithKey f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] adjustWithKey f 7 empty == empty O(min(n,W)). The expression ( f k map) updates the value x at k (if it is in the map). If (f x) is %, the element is deleted. If it is ( y ), the key k is bound to the new value y. let f x = if x == "a" then Just "new a" else Nothing update f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] update f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] update f 3 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" O(min(n,W)). The expression ( f k map) updates the value x at k (if it is in the map). If (f k x) is %, the element is deleted. If it is ( y ), the key k is bound to the new value y. 0let f k x = if x == "a" then Just ((show k) ++ ":new a") else Nothing updateWithKey f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:new a")] updateWithKey f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] updateWithKey f 3 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" O(min(n,W))n. Lookup and update. The function returns original value, if it is updated. This is different behavior than  >. Returns the original key value if the map entry is deleted. flet f k x = if x == "a" then Just ((show k) ++ ":new a") else Nothing updateLookupWithKey f 5 (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "5:new a")]) updateLookupWithKey f 7 (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a")]) updateLookupWithKey f 3 (fromList [(5,"a"), (3,"b")]) == (Just "b", singleton 5 "a") O(min(n,W)). The expression ( f k map) alters the value x at k, or absence thereof. 8 can be used to insert, delete, or update a value in an s. In short : z k ( f k m) = f (z k m).The union of a list of maps. 9unions [(fromList [(5, "a"), (3, "b")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "A3"), (3, "B3")])] == fromList [(3, "b"), (5, "a"), (7, "C")] unions [(fromList [(5, "A3"), (3, "B3")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "a"), (3, "b")])] == fromList [(3, "B3"), (5, "A3"), (7, "C")]8The union of a list of maps, with a combining operation. unionsWith (++) [(fromList [(5, "a"), (3, "b")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "A3"), (3, "B3")])] == fromList [(3, "bB3"), (5, "aAA3"), (7, "C")]O(n+m)m. The (left-biased) union of two maps. It prefers the first map when duplicate keys are encountered, i.e. ( ==  ). punion (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "a"), (7, "C")]O(n+m)&. The union with a combining function. zunionWith (++) (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "aA"), (7, "C")]O(n+m)&. The union with a combining function. let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value unionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "5:a|A"), (7, "C")]O(n+m).. Difference between two maps (based on keys). ]difference (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 3 "b"O(n+m)'. Difference with a combining function. let f al ar = if al == "b" then Just (al ++ ":" ++ ar) else Nothing differenceWith f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (3, "B"), (7, "C")]) == singleton 3 "b:B"O(n+m). Difference with a combining function. When two equal keys are encountered, the combining function is applied to the key and both values. If it returns D, the element is discarded (proper set difference). If it returns ( y+), the element is updated with a new value y. let f k al ar = if al == "b" then Just ((show k) ++ ":" ++ al ++ "|" ++ ar) else Nothing differenceWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (3, "B"), (10, "C")]) == singleton 3 "3:b|B"O(n+m)=. The (left-biased) intersection of two maps (based on keys). _intersection (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "a"O(n+m)-. The intersection with a combining function. iintersectionWith (++) (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "aA"O(n+m)-. The intersection with a combining function. let f k al ar = (show k) ++ ":" ++ al ++ "|" ++ ar intersectionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "5:a|A"O(n+m):. A high-performance universal combining function. Using \, all combining functions can be defined without any loss of efficiency (with exception of ,  and ,, where sharing of some nodes is lost with ).6Please make sure you know what is going on when using f, otherwise you can be surprised by unexpected code growth or even corruption of the data structure.When U is given three arguments, it is inlined to the call site. You should therefore use P only to define your custom combining functions. For example, you could define ,  and  as myUnionWithKey f m1 m2 = mergeWithKey (\k x1 x2 -> Just (f k x1 x2)) id id m1 m2 myDifferenceWithKey f m1 m2 = mergeWithKey f id (const empty) m1 m2 myIntersectionWithKey f m1 m2 = mergeWithKey (\k x1 x2 -> Just (f k x1 x2)) (const empty) (const empty) m1 m2 When calling  combine only1 only2, a function combining two ss is created, such thatXif a key is present in both maps, it is passed with both corresponding values to the combinet function. Depending on the result, the key is either present in the result with specified value, or is left out;>a nonempty subtree present only in the first map is passed to only1* and the output is added to the result;?a nonempty subtree present only in the second map is passed to only2* and the output is added to the result.The only1 and only2 methods Mmust return a map with a subset (possibly empty) of the keys of the given mapC. The values can be modified arbitrarily. Most common variants of only1 and only2 are  and  , but for example  f or  f could be used for any f. O(min(n,W))&. Update the value at the minimal key. updateMinWithKey (\ k a -> Just ((show k) ++ ":" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3,"3:b"), (5,"a")] updateMinWithKey (\ _ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" O(min(n,W))&. Update the value at the maximal key. updateMaxWithKey (\ k a -> Just ((show k) ++ ":" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3,"b"), (5,"5:a")] updateMaxWithKey (\ _ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" O(min(n,W))_. Retrieves the maximal (key,value) pair of the map, and the map stripped of that element, or  if passed an empty map. omaxViewWithKey (fromList [(5,"a"), (3,"b")]) == Just ((5,"a"), singleton 3 "b") maxViewWithKey empty == Nothing O(min(n,W))_. Retrieves the minimal (key,value) pair of the map, and the map stripped of that element, or  if passed an empty map. ominViewWithKey (fromList [(5,"a"), (3,"b")]) == Just ((3,"b"), singleton 5 "a") minViewWithKey empty == Nothing O(min(n,W))&. Update the value at the maximal key. updateMax (\ a -> Just ("X" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "Xa")] updateMax (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" O(min(n,W))&. Update the value at the minimal key. updateMin (\ a -> Just ("X" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3, "Xb"), (5, "a")] updateMin (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" O(min(n,W))R. Retrieves the maximal key of the map, and the map stripped of that element, or  if passed an empty map. O(min(n,W))R. Retrieves the minimal key of the map, and the map stripped of that element, or  if passed an empty map. O(min(n,W))&. Delete and find the maximal element. O(min(n,W))&. Delete and find the minimal element. O(min(n,W)). The minimal key of the map. O(min(n,W)). The maximal key of the map. O(min(n,W))C. Delete the minimal key. Returns an empty map if the map is empty.=Note that this is a change of behaviour for consistency with !0  versions prior to 0.5 threw an error if the s was already empty. O(min(n,W))C. Delete the maximal key. Returns an empty map if the map is empty.=Note that this is a change of behaviour for consistency with !0  versions prior to 0.5 threw an error if the s was already empty.O(n+m)F. Is this a proper submap? (ie. a submap but not equal). Defined as ( =  (==)).O(n+m)J. Is this a proper submap? (ie. a submap but not equal). The expression ( f m1 m2 ) returns  when m1 and m2 are not equal, all keys in m1 are in m2 , and when f returns [ when applied to their respective values. For example, the following expressions are all : isProperSubmapOfBy (==) (fromList [(1,1)]) (fromList [(1,1),(2,2)]) isProperSubmapOfBy (<=) (fromList [(1,1)]) (fromList [(1,1),(2,2)])But the following are all : isProperSubmapOfBy (==) (fromList [(1,1),(2,2)]) (fromList [(1,1),(2,2)]) isProperSubmapOfBy (==) (fromList [(1,1),(2,2)]) (fromList [(1,1)]) isProperSubmapOfBy (<) (fromList [(1,1)]) (fromList [(1,1),(2,2)])O(n+m)!. Is this a submap? Defined as ( =  (==)).O(n+m). The expression ( f m1 m2 ) returns  if all keys in m1 are in m2 , and when f returns [ when applied to their respective values. For example, the following expressions are all : isSubmapOfBy (==) (fromList [(1,1)]) (fromList [(1,1),(2,2)]) isSubmapOfBy (<=) (fromList [(1,1)]) (fromList [(1,1),(2,2)]) isSubmapOfBy (==) (fromList [(1,1),(2,2)]) (fromList [(1,1),(2,2)])But the following are all : isSubmapOfBy (==) (fromList [(1,2)]) (fromList [(1,1),(2,2)]) isSubmapOfBy (<) (fromList [(1,1)]) (fromList [(1,1),(2,2)]) isSubmapOfBy (==) (fromList [(1,1),(2,2)]) (fromList [(1,1)])O(n),. Map a function over all values in the map. Mmap (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]O(n),. Map a function over all values in the map. tlet f key x = (show key) ++ ":" ++ x mapWithKey f (fromList [(5,"a"), (3,"b")]) == fromList [(3, "3:b"), (5, "5:a")]O(n).  f s ==   $  ((k, v) -> (,) k  $ f k v) ( m)* That is, behaves exactly like a regular Y except that the traversing function also has access to the key associated with a value. traverseWithKey (\k v -> if odd k then Just (succ v) else Nothing) (fromList [(1, 'a'), (5, 'e')]) == Just (fromList [(1, 'b'), (5, 'f')]) traverseWithKey (\k v -> if odd k then Just (succ v) else Nothing) (fromList [(2, 'c')]) == NothingO(n). The function N threads an accumulating argument through the map in ascending order of keys. let f a b = (a ++ b, b ++ "X") mapAccum f "Everything: " (fromList [(5,"a"), (3,"b")]) == ("Everything: ba", fromList [(3, "bX"), (5, "aX")])O(n). The function N threads an accumulating argument through the map in ascending order of keys. let f a k b = (a ++ " " ++ (show k) ++ "-" ++ b, b ++ "X") mapAccumWithKey f "Everything:" (fromList [(5,"a"), (3,"b")]) == ("Everything: 3-b 5-a", fromList [(3, "bX"), (5, "aX")])O(n). The function N threads an accumulating argument through the map in ascending order of keys.O(n). The function  mapAccumRO threads an accumulating argument through the map in descending order of keys. O(n*min(n,W)).  f s! is the map obtained by applying f to each key of s.)The size of the result may be smaller if f maps two or more distinct keys to the same new key. In this case the value at the greatest of the original keys is retained. mapKeys (+ 1) (fromList [(5,"a"), (3,"b")]) == fromList [(4, "b"), (6, "a")] mapKeys (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "c" mapKeys (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "c" O(n*min(n,W)).  c f s! is the map obtained by applying f to each key of s.)The size of the result may be smaller if fr maps two or more distinct keys to the same new key. In this case the associated values will be combined using c. mapKeysWith (++) (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "cdab" mapKeysWith (++) (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "cdab" O(n*min(n,W)).  f s ==  f s, but works only when f2 is strictly monotonic. That is, for any values x and y, if x < y then f x < f y.  The precondition is not checked. Semi-formally, we have: ~and [x < y ==> f x < f y | x <- ls, y <- ls] ==> mapKeysMonotonic f s == mapKeys f s where ls = keys sThis means that fm maps distinct original keys to distinct resulting keys. This function has slightly better performance than . _mapKeysMonotonic (\ k -> k * 2) (fromList [(5,"a"), (3,"b")]) == fromList [(6, "b"), (10, "a")]O(n)0. Filter all values that satisfy some predicate. filter (> "a") (fromList [(5,"a"), (3,"b")]) == singleton 3 "b" filter (> "x") (fromList [(5,"a"), (3,"b")]) == empty filter (< "a") (fromList [(5,"a"), (3,"b")]) == emptyO(n)5. Filter all keys/values that satisfy some predicate. NfilterWithKey (\k _ -> k > 4) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(n). Partition the map according to some predicate. The first map contains all elements that satisfy the predicate, the second all elements that fail the predicate. See also .  partition (> "a") (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", singleton 5 "a") partition (< "x") (fromList [(5,"a"), (3,"b")]) == (fromList [(3, "b"), (5, "a")], empty) partition (> "x") (fromList [(5,"a"), (3,"b")]) == (empty, fromList [(3, "b"), (5, "a")])O(n). Partition the map according to some predicate. The first map contains all elements that satisfy the predicate, the second all elements that fail the predicate. See also . 9partitionWithKey (\ k _ -> k > 3) (fromList [(5,"a"), (3,"b")]) == (singleton 5 "a", singleton 3 "b") partitionWithKey (\ k _ -> k < 7) (fromList [(5,"a"), (3,"b")]) == (fromList [(3, "b"), (5, "a")], empty) partitionWithKey (\ k _ -> k > 7) (fromList [(5,"a"), (3,"b")]) == (empty, fromList [(3, "b"), (5, "a")])O(n). Map values and collect the  results. tlet f x = if x == "a" then Just "new a" else Nothing mapMaybe f (fromList [(5,"a"), (3,"b")]) == singleton 5 "new a"O(n)". Map keys/values and collect the  results. let f k _ = if k < 5 then Just ("key : " ++ (show k)) else Nothing mapMaybeWithKey f (fromList [(5,"a"), (3,"b")]) == singleton 3 "key : 3"O(n). Map values and separate the  and  results. 5let f a = if a < "c" then Left a else Right a mapEither f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (fromList [(3,"b"), (5,"a")], fromList [(1,"x"), (7,"z")]) mapEither (\ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (empty, fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])O(n)#. Map keys/values and separate the  and  results. Olet f k a = if k < 5 then Left (k * 2) else Right (a ++ a) mapEitherWithKey f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (fromList [(1,2), (3,6)], fromList [(5,"aa"), (7,"zz")]) mapEitherWithKey (\_ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (empty, fromList [(1,"x"), (3,"b"), (5,"a"), (7,"z")]) O(min(n,W)). The expression ( k map ) is a pair  (map1,map2) where all keys in map1 are lower than k and all keys in map2 larger than k. Any key equal to k is found in neither map1 nor map2. ksplit 2 (fromList [(5,"a"), (3,"b")]) == (empty, fromList [(3,"b"), (5,"a")]) split 3 (fromList [(5,"a"), (3,"b")]) == (empty, singleton 5 "a") split 4 (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", singleton 5 "a") split 5 (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", empty) split 6 (fromList [(5,"a"), (3,"b")]) == (fromList [(3,"b"), (5,"a")], empty) O(min(n,W)) . Performs a G but also returns whether the pivot key was found in the original map. splitLookup 2 (fromList [(5,"a"), (3,"b")]) == (empty, Nothing, fromList [(3,"b"), (5,"a")]) splitLookup 3 (fromList [(5,"a"), (3,"b")]) == (empty, Just "b", singleton 5 "a") splitLookup 4 (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", Nothing, singleton 5 "a") splitLookup 5 (fromList [(5,"a"), (3,"b")]) == (singleton 3 "b", Just "a", empty) splitLookup 6 (fromList [(5,"a"), (3,"b")]) == (fromList [(3,"b"), (5,"a")], Nothing, empty)O(n)[. Fold the values in the map using the given right-associative binary operator, such that  f z ==  f z . . For example, elems map = foldr (:) [] map Mlet f a len = len + (length a) foldr f 0 (fromList [(5,"a"), (3,"bbb")]) == 4O(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)Z. Fold the values in the map using the given left-associative binary operator, such that  f z ==  f z . . For example, %elems = reverse . foldl (flip (:)) [] Mlet f len a = len + (length a) foldl f 0 (fromList [(5,"a"), (3,"bbb")]) == 4O(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)e. Fold the keys and values in the map using the given right-associative binary operator, such that  f z ==  ( f) z . . For example, 0keys map = foldrWithKey (\k x ks -> k:ks) [] map let f k a result = result ++ "(" ++ (show k) ++ ":" ++ a ++ ")" foldrWithKey f "Map: " (fromList [(5,"a"), (3,"b")]) == "Map: (5:a)(3:b)"O(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)d. Fold the keys and values in the map using the given left-associative binary operator, such that  f z ==  (\z' (kx, x) -> f z' kx x) z . . For example, 2keys = reverse . foldlWithKey (\ks k x -> k:ks) [] let f result k a = result ++ "(" ++ (show k) ++ ":" ++ a ++ ")" foldlWithKey f "Map: " (fromList [(5,"a"), (3,"b")]) == "Map: (3:b)(5:a)"O(n). A strict version of . Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.O(n)G. Fold the keys and values in the map using the given monoid, such that  f =  .  f*This can be an asymptotically faster than  or  for some monoids.O(n)`. Return all elements of the map in the ascending order of their keys. Subject to list fusion. Belems (fromList [(5,"a"), (3,"b")]) == ["b","a"] elems empty == []O(n)I. Return all keys of the map in ascending order. Subject to list fusion. <keys (fromList [(5,"a"), (3,"b")]) == [3,5] keys empty == []O(n). An alias for Y. Returns all key/value pairs in the map in ascending key order. Subject to list fusion. Massocs (fromList [(5,"a"), (3,"b")]) == [(3,"b"), (5,"a")] assocs empty == [] O(n*min(n,W))!. The set of all keys of the map. fkeysSet (fromList [(5,"a"), (3,"b")]) == Data.IntSet.fromList [3,5] keysSet empty == Data.IntSet.emptyO(n)W. Build a map from a set of keys and a function which for each key computes its value. fromSet (\k -> replicate k 'a') (Data.IntSet.fromList [3, 5]) == fromList [(5,"aaaaa"), (3,"aaa")] fromSet undefined Data.IntSet.empty == emptyO(n)H. Convert the map to a list of key/value pairs. Subject to list fusion. MtoList (fromList [(5,"a"), (3,"b")]) == [(3,"b"), (5,"a")] toList empty == []O(n)n. Convert the map to a list of key/value pairs where the keys are in ascending order. Subject to list fusion. =toAscList (fromList [(5,"a"), (3,"b")]) == [(3,"b"), (5,"a")]O(n)o. Convert the map to a list of key/value pairs where the keys are in descending order. Subject to list fusion. >toDescList (fromList [(5,"a"), (3,"b")]) == [(5,"a"), (3,"b")] O(n*min(n,W)).. Create a map from a list of key/value pairs. fromList [] == empty fromList [(5,"a"), (3,"b"), (5, "c")] == fromList [(5,"c"), (3,"b")] fromList [(5,"c"), (3,"b"), (5, "a")] == fromList [(5,"a"), (3,"b")] O(n*min(n,W))R. Create a map from a list of key/value pairs with a combining function. See also . fromListWith (++) [(5,"a"), (5,"b"), (3,"b"), (3,"a"), (5,"c")] == fromList [(3, "ab"), (5, "cba")] fromListWith (++) [] == empty O(n*min(n,W))e. Build a map from a list of key/value pairs with a combining function. See also fromAscListWithKey'. let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value fromListWithKey f [(5,"a"), (5,"b"), (3,"b"), (3,"a"), (5,"c")] == fromList [(3, "3:a|b"), (5, "5:c|5:b|a")] fromListWithKey f [] == emptyO(n)T. Build a map from a list of key/value pairs where the keys are in ascending order. fromAscList [(3,"b"), (5,"a")] == fromList [(3, "b"), (5, "a")] fromAscList [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "b")]O(n). Build a map from a list of key/value pairs where the keys are in ascending order, with a combining function on equal keys. :The precondition (input list is ascending) is not checked. RfromAscListWith (++) [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "ba")]O(n). Build a map from a list of key/value pairs where the keys are in ascending order, with a combining function on equal keys. :The precondition (input list is ascending) is not checked. let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value fromAscListWithKey f [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "5:b|a")]O(n)g. Build a map from a list of key/value pairs where the keys are in ascending order and all distinct. CThe precondition (input list is strictly ascending) is not checked. GfromDistinctAscList [(3,"b"), (5,"a")] == fromList [(3, "b"), (5, "a")]O(1). Decompose a map into pieces based on the structure of the underlying tree. This function is useful for consuming a map in parallel.No guarantee is made as to the sizes of the pieces; an internal, but deterministic process determines this. However, it is guaranteed that the pieces returned will be in ascending order (all elements in the first submap less than all elements in the second, and so on). Examples: {splitRoot (fromList (zip [1..6::Int] ['a'..])) == [fromList [(1,'a'),(2,'b'),(3,'c')],fromList [(4,'d'),(5,'e'),(6,'f')]] splitRoot empty == []Note that the current implementation does not return more than two submaps, but you should not depend on this behaviour because it can change in the future without notice.O(n)\. Show the tree that implements the map. The tree is shown in a compressed, hanging format.O(n). The expression ( hang wide map.) shows the tree that implements the map. If hang is , a hanging6 tree is shown otherwise a rotated tree is shown. If wide is !, an extra wide version is shown.stuvwxyz{|}~zQBstuvwxyz{|}~stuvwxyz{|}~u @(c) Daan Leijen 2002 (c) Andriy Palamarchuk 2008 BSD-stylelibraries@haskell.org provisionalportable Trustworthy+ O(min(n,W)). The expression ( def k map) returns the value at key k or returns def, when the key is not an element of the map. ufindWithDefault 'x' 1 (fromList [(5,'a'), (3,'b')]) == 'x' findWithDefault 'x' 5 (fromList [(5,'a'), (3,'b')]) == 'a'O(1). A map of one element. Isingleton 1 'a' == fromList [(1, 'a')] size (singleton 1 'a') == 1 O(min(n,W)). Insert a new key/value pair in the map. If the key is already present in the map, the associated value is replaced with the supplied value, i.e.  is equivalent to  . insert 5 'x' (fromList [(5,'a'), (3,'b')]) == fromList [(3, 'b'), (5, 'x')] insert 7 'x' (fromList [(5,'a'), (3,'b')]) == fromList [(3, 'b'), (5, 'a'), (7, 'x')] insert 5 'x' empty == singleton 5 'x' O(min(n,W))%. Insert with a combining function.  f key value mp) will insert the pair (key, value) into mpU if key does not exist in the map. If the key does exist, the function will insert f new_value old_value. insertWith (++) 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "xxxa")] insertWith (++) 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")] insertWith (++) 5 "xxx" empty == singleton 5 "xxx" O(min(n,W))%. Insert with a combining function.  f key value mp) will insert the pair (key, value) into mpU if key does not exist in the map. If the key does exist, the function will insert f key new_value old_value. ]let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")] insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")] insertWithKey f 5 "xxx" empty == singleton 5 "xxx"7If the key exists in the map, this function is lazy in x but strict in the result of f. O(min(n,W)). The expression ( f k x map2) is a pair where the first element is equal to (z k map$) and the second element equal to ( f k x map). let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value insertLookupWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "5:xxx|a")]) insertLookupWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a"), (7, "xxx")]) insertLookupWithKey f 5 "xxx" empty == (Nothing, singleton 5 "xxx")This is how to define  insertLookup using insertLookupWithKey: let insertLookup kx x t = insertLookupWithKey (\_ a _ -> a) kx x t insertLookup 5 "x" (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "x")]) insertLookup 7 "x" (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a"), (7, "x")]) O(min(n,W))k. Adjust a value at a specific key. When the key is not a member of the map, the original map is returned. adjust ("new " ++) 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] adjust ("new " ++) 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] adjust ("new " ++) 7 empty == empty O(min(n,W))k. Adjust a value at a specific key. When the key is not a member of the map, the original map is returned.  let f key x = (show key) ++ ":new " ++ x adjustWithKey f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:new a")] adjustWithKey f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] adjustWithKey f 7 empty == empty O(min(n,W)). The expression ( f k map) updates the value x at k (if it is in the map). If (f x) is %, the element is deleted. If it is ( y ), the key k is bound to the new value y. let f x = if x == "a" then Just "new a" else Nothing update f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] update f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] update f 3 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" O(min(n,W)). The expression ( f k map) updates the value x at k (if it is in the map). If (f k x) is %, the element is deleted. If it is ( y ), the key k is bound to the new value y. 0let f k x = if x == "a" then Just ((show k) ++ ":new a") else Nothing updateWithKey f 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:new a")] updateWithKey f 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] updateWithKey f 3 (fromList [(5,"a"), (3,"b")]) == singleton 5 "a" O(min(n,W))n. Lookup and update. The function returns original value, if it is updated. This is different behavior than  >. Returns the original key value if the map entry is deleted. flet f k x = if x == "a" then Just ((show k) ++ ":new a") else Nothing updateLookupWithKey f 5 (fromList [(5,"a"), (3,"b")]) == (Just "a", fromList [(3, "b"), (5, "5:new a")]) updateLookupWithKey f 7 (fromList [(5,"a"), (3,"b")]) == (Nothing, fromList [(3, "b"), (5, "a")]) updateLookupWithKey f 3 (fromList [(5,"a"), (3,"b")]) == (Just "b", singleton 5 "a") O(min(n,W)). The expression ( f k map) alters the value x at k, or absence thereof. 8 can be used to insert, delete, or update a value in an s. In short : z k ( f k m) = f (z k m).8The union of a list of maps, with a combining operation. unionsWith (++) [(fromList [(5, "a"), (3, "b")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "A3"), (3, "B3")])] == fromList [(3, "bB3"), (5, "aAA3"), (7, "C")]O(n+m)&. The union with a combining function. zunionWith (++) (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "aA"), (7, "C")]O(n+m)&. The union with a combining function. let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value unionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "5:a|A"), (7, "C")]O(n+m)'. Difference with a combining function. let f al ar = if al == "b" then Just (al ++ ":" ++ ar) else Nothing differenceWith f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (3, "B"), (7, "C")]) == singleton 3 "b:B"O(n+m). Difference with a combining function. When two equal keys are encountered, the combining function is applied to the key and both values. If it returns D, the element is discarded (proper set difference). If it returns ( y+), the element is updated with a new value y. let f k al ar = if al == "b" then Just ((show k) ++ ":" ++ al ++ "|" ++ ar) else Nothing differenceWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (3, "B"), (10, "C")]) == singleton 3 "3:b|B"O(n+m)-. The intersection with a combining function. iintersectionWith (++) (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "aA"O(n+m)-. The intersection with a combining function. let f k al ar = (show k) ++ ":" ++ al ++ "|" ++ ar intersectionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == singleton 5 "5:a|A"O(n+m):. A high-performance universal combining function. Using \, all combining functions can be defined without any loss of efficiency (with exception of ,  and ,, where sharing of some nodes is lost with ).6Please make sure you know what is going on when using f, otherwise you can be surprised by unexpected code growth or even corruption of the data structure.When U is given three arguments, it is inlined to the call site. You should therefore use P only to define your custom combining functions. For example, you could define ,  and  as myUnionWithKey f m1 m2 = mergeWithKey (\k x1 x2 -> Just (f k x1 x2)) id id m1 m2 myDifferenceWithKey f m1 m2 = mergeWithKey f id (const empty) m1 m2 myIntersectionWithKey f m1 m2 = mergeWithKey (\k x1 x2 -> Just (f k x1 x2)) (const empty) (const empty) m1 m2 When calling  combine only1 only2, a function combining two ss is created, such thatXif a key is present in both maps, it is passed with both corresponding values to the combinet function. Depending on the result, the key is either present in the result with specified value, or is left out;>a nonempty subtree present only in the first map is passed to only1* and the output is added to the result;?a nonempty subtree present only in the second map is passed to only2* and the output is added to the result.The only1 and only2 methods Mmust return a map with a subset (possibly empty) of the keys of the given mapD. The values can be modified arbitrarily. Most common variants of only1 and only2 are  and  , but for example  f or  f could be used for any f.O(log n)&. Update the value at the minimal key. updateMinWithKey (\ k a -> Just ((show k) ++ ":" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3,"3:b"), (5,"a")] updateMinWithKey (\ _ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(log n)&. Update the value at the maximal key. updateMaxWithKey (\ k a -> Just ((show k) ++ ":" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3,"b"), (5,"5:a")] updateMaxWithKey (\ _ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 3 "b"O(log n)&. Update the value at the maximal key. updateMax (\ a -> Just ("X" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "Xa")] updateMax (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 3 "b"O(log n)&. Update the value at the minimal key. updateMin (\ a -> Just ("X" ++ a)) (fromList [(5,"a"), (3,"b")]) == fromList [(3, "Xb"), (5, "a")] updateMin (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) == singleton 5 "a"O(n),. Map a function over all values in the map. Mmap (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]O(n),. Map a function over all values in the map. tlet f key x = (show key) ++ ":" ++ x mapWithKey f (fromList [(5,"a"), (3,"b")]) == fromList [(3, "3:b"), (5, "5:a")]O(n). The function N threads an accumulating argument through the map in ascending order of keys. let f a b = (a ++ b, b ++ "X") mapAccum f "Everything: " (fromList [(5,"a"), (3,"b")]) == ("Everything: ba", fromList [(3, "bX"), (5, "aX")])O(n). The function N threads an accumulating argument through the map in ascending order of keys. let f a k b = (a ++ " " ++ (show k) ++ "-" ++ b, b ++ "X") mapAccumWithKey f "Everything:" (fromList [(5,"a"), (3,"b")]) == ("Everything: 3-b 5-a", fromList [(3, "bX"), (5, "aX")])O(n). The function  threads an accumulating argument through the map in ascending order of keys. Strict in the accumulating argument and the both elements of the result of the function.O(n). The function  mapAccumRO threads an accumulating argument through the map in descending order of keys. O(n*log n).  c f s! is the map obtained by applying f to each key of s.)The size of the result may be smaller if fr maps two or more distinct keys to the same new key. In this case the associated values will be combined using c. mapKeysWith (++) (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "cdab" mapKeysWith (++) (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "cdab"O(n). Map values and collect the  results. tlet f x = if x == "a" then Just "new a" else Nothing mapMaybe f (fromList [(5,"a"), (3,"b")]) == singleton 5 "new a"O(n)". Map keys/values and collect the  results. let f k _ = if k < 5 then Just ("key : " ++ (show k)) else Nothing mapMaybeWithKey f (fromList [(5,"a"), (3,"b")]) == singleton 3 "key : 3"O(n). Map values and separate the  and  results. 5let f a = if a < "c" then Left a else Right a mapEither f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (fromList [(3,"b"), (5,"a")], fromList [(1,"x"), (7,"z")]) mapEither (\ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (empty, fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])O(n)#. Map keys/values and separate the  and  results. Olet f k a = if k < 5 then Left (k * 2) else Right (a ++ a) mapEitherWithKey f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (fromList [(1,2), (3,6)], fromList [(5,"aa"), (7,"zz")]) mapEitherWithKey (\_ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) == (empty, fromList [(1,"x"), (3,"b"), (5,"a"), (7,"z")])O(n)W. Build a map from a set of keys and a function which for each key computes its value. fromSet (\k -> replicate k 'a') (Data.IntSet.fromList [3, 5]) == fromList [(5,"aaaaa"), (3,"aaa")] fromSet undefined Data.IntSet.empty == empty O(n*min(n,W)).. Create a map from a list of key/value pairs. fromList [] == empty fromList [(5,"a"), (3,"b"), (5, "c")] == fromList [(5,"c"), (3,"b")] fromList [(5,"c"), (3,"b"), (5, "a")] == fromList [(5,"a"), (3,"b")] O(n*min(n,W))R. Create a map from a list of key/value pairs with a combining function. See also . fromListWith (++) [(5,"a"), (5,"b"), (3,"b"), (3,"a"), (5,"a")] == fromList [(3, "ab"), (5, "aba")] fromListWith (++) [] == empty O(n*min(n,W))e. Build a map from a list of key/value pairs with a combining function. See also fromAscListWithKey'. fromListWith (++) [(5,"a"), (5,"b"), (3,"b"), (3,"a"), (5,"a")] == fromList [(3, "ab"), (5, "aba")] fromListWith (++) [] == emptyO(n)T. Build a map from a list of key/value pairs where the keys are in ascending order. fromAscList [(3,"b"), (5,"a")] == fromList [(3, "b"), (5, "a")] fromAscList [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "b")]O(n). Build a map from a list of key/value pairs where the keys are in ascending order, with a combining function on equal keys. :The precondition (input list is ascending) is not checked. RfromAscListWith (++) [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "ba")]O(n). Build a map from a list of key/value pairs where the keys are in ascending order, with a combining function on equal keys. :The precondition (input list is ascending) is not checked. RfromAscListWith (++) [(3,"b"), (5,"a"), (5,"b")] == fromList [(3, "b"), (5, "ba")]O(n)g. Build a map from a list of key/value pairs where the keys are in ascending order and all distinct. CThe precondition (input list is strictly ascending) is not checked. GfromDistinctAscList [(3,"b"), (5,"a")] == fromList [(3, "b"), (5, "a")].gBstuvwxyz|}~gsBtuvwxyz|}~, @(c) Daan Leijen 2002 (c) Andriy Palamarchuk 2008 BSD-stylelibraries@haskell.org provisionalportableSafegBstuvwxyz{|}~gsBtuvwxyz{|}~ @(c) Daan Leijen 2002 (c) Andriy Palamarchuk 2008 BSD-stylelibraries@haskell.org provisionalportableSafe Deprecated.! As of version 0.5, replaced by  .O(log n) . Same as \, but the result of the combining function is evaluated to WHNF before inserted to the map. Deprecated.! As of version 0.5, replaced by  .O(log n) . Same as \, but the result of the combining function is evaluated to WHNF before inserted to the map. Deprecated. As of version 0.5, replaced by .O(n)t. Fold the values in the map using the given right-associative binary operator. This function is an equivalent of ' and is present for compatibility only. Deprecated. As of version 0.5, replaced by .O(n)}. Fold the keys and values in the map using the given right-associative binary operator. This function is an equivalent of ' and is present for compatibility only.kBstuvwxyz{|}~"#$%&'()*+, -./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~3)*QPZ!3)*=< QPZ*=< Z3)*QPZ3)*=< QPZ *    = < Z           !""#h$%&'()*+,-./0123456789(:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~      !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMN !"#O%&P Q*+6789:;<,RSTUVWXYZ[\    ]5PdUpygona5BnJSIVjEHwZ Data.Sequence Data.Tree Data.GraphData.Set Data.Map.LazyData.Map.StrictData.Map Data.IntSetData.IntMap.StrictData.IntMap.Lazy Data.IntMap Control.Monad replicateMData.Utils.StrictPairData.Utils.StrictFold Data.Listfoldl' Data.Set.BasePreludefoldrfoldl Data.Map.Basefold insertWith insertWithKeyinsertLookupWithKeyData.Utils.BitUtilData.IntSet.BaseSetData.IntMap.BaselookupupdateLookupWithKeyMapViewREmptyR:>ViewLEmptyL:<Seqempty singleton replicate replicateA<||>><unfoldrunfoldliterateNnulllengthviewlviewrscanlscanl1scanrscanr1indexupdateadjust 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