map :: (a -> b) -> Map k a -> Map k b

containers - Data.Map.Lazy  

O(n). Map a function over all values in the map.

 map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
map :: (a -> b) -> IntervalMap k a -> IntervalMap k b

IntervalMap - Data.IntervalMap.Lazy  

O(n). Map a function over all values in the map.

map :: (v -> t) -> EnumMapMap k v -> EnumMapMap k t Class Method

enummapmap - Data.EnumMapMap.Lazy  

Map a function over all values in the EnumMapMap.

map :: (a -> b) -> IntMap a -> IntMap b

containers - Data.IntMap.Lazy  

O(n). Map a function over all values in the map.

 map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
map :: (v -> w) -> CritBit k v -> CritBit k w

critbit - Data.CritBit.Map.Lazy  

O(n). Apply a function to all values.

 map show (fromList [("b",5), ("a",3)]) == fromList [("b","5"), ("a","3")]
map :: (Word8 -> Word8) -> ByteString -> ByteString

bytestring - Data.ByteString.Lazy  

O(n) map f xs is the ByteString obtained by applying f to each element of xs.

map :: (Char -> Char) -> ByteString -> ByteString

vector-bytestring - Data.Vector.Storable.ByteString.Lazy.Char8  

O(n) map f xs is the ByteString obtained by applying f to each element of xs

map :: (Char -> Char) -> Text -> Text

text - Data.Text.Lazy  

O(n) map f t is the Text obtained by applying f to each element of t. Subject to fusion. Performs replacement on invalid scalar values.

map :: forall k a b. (a -> b) -> EnumMap k a -> EnumMap k b
map :: (v1 -> v2) -> HashMap k v1 -> HashMap k v2

unordered-containers - Data.HashMap.Lazy  

O(n) Transform this map by applying a function to every value.

map :: (Word8 -> Word8) -> ByteString -> ByteString

vector-bytestring - Data.Vector.Storable.ByteString.Lazy  

O(n) map f xs is the ByteString obtained by applying f to each element of xs.

map :: (Char -> Char) -> ByteString -> ByteString

bytestring - Data.ByteString.Lazy.Char8  

O(n) map f xs is the ByteString obtained by applying f to each element of xs

containers - Data.Map.Lazy  

An efficient implementation of ordered maps from keys to values (dictionaries).

API of this module is strict in the keys, but lazy in the values. If you need value-strict maps, use Data.Map.Strict instead. The Map type itself is shared between the lazy and strict modules, meaning that the same Map value can be passed to functions in both modules (although that is rarely needed).

These modules are intended to be imported qualified, to avoid name clashes with Prelude functions, e.g.

  import qualified Data.Map.Lazy as Map

The implementation of Map is based on size balanced binary trees (or trees of bounded balance) as described by:

  • Stephen Adams, "Efficient sets: a balancing act", Journal of Functional Programming 3(4):553-562, October 1993, http://www.swiss.ai.mit.edu/~adams/BB/.
  • J. Nievergelt and E.M. Reingold, "Binary search trees of bounded balance", SIAM journal of computing 2(1), March 1973.

Note that the implementation is left-biased -- the elements of a first argument are always preferred to the second, for example in union or insert.

Operation comments contain the operation time complexity in the Big-O notation (http://en.wikipedia.org/wiki/Big_O_notation).

showTreeWith :: (k -> a -> String) -> Bool -> Bool -> Map k a -> String

containers - Data.Map.Lazy  

O(n). The expression (showTreeWith showelem hang wide map) shows the tree that implements the map. Elements are shown using the showElem function. If hang is True, a hanging tree is shown otherwise a rotated tree is shown. If wide is True, 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,())

containers - Data.Map.Lazy  Data.Map.Strict  

O(1). Is the map empty?

 Data.Map.null (empty)           == True
 Data.Map.null (singleton 1 'a') == False
foldrWithKey :: (k -> a -> b -> b) -> b -> Map k a -> b

containers - Data.Map.Lazy  

O(n). Fold the keys and values in the map using the given right-associative binary operator, such that foldrWithKey f z == foldr (uncurry f) z . toAscList.

For example,

 keys 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)"
foldrWithKey :: (k -> v -> a -> a) -> a -> CritBit k v -> a

critbit - Data.CritBit.Map.Lazy  

O(n). Fold the keys and values in the map using the given right-associative function, such that foldrWithKey f z == foldr (uncurry f) z . toAscList.

Examples:

 keys map = foldrWithKey (\k x ks -> k:ks) [] map
 let f k a result = result ++ "(" ++ show k ++ ":" ++ a ++ ")"
 foldrWithKey f "Map: " (fromList [("a",5), ("b",3)]) == "Map: (a:5)(b:3)"