# map -package:base -is:exact -is:exact -package:Cabal -package:bytestring -package:ghc -package:aeson

O(n). Map a function over all values in the map.
```map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
```
O(n*min(n,W)). map f s is the set obtained by applying f to each element of s. It's worth noting that the size of the result may be smaller if, for some (x,y), x /= y && f x == f y
O(n). Map a function over all values in the map.
```map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
```
O(n*log n). map f s is the set obtained by applying f to each element of s. It's worth noting that the size of the result may be smaller if, for some (x,y), x /= y && f x == f y
O(n) map f t is the Text obtained by applying f to each element of t. Example:
```>>> let message = pack "I am not angry. Not at all."

>>> T.map (\c -> if c == '.' then '!' else c) message
"I am not angry! Not at all!"
```
Performs replacement on invalid scalar values.
O(n) map f xs is the Stream Char obtained by applying f to each element of xs. Properties
```unstream . map f . stream = map f
```
O(n) map f t is the Text obtained by applying f to each element of t. Performs replacement on invalid scalar values.
O(n) Map a function over a vector.
Map a function over a Bundle
O(n) Map a function over a vector.
O(n) Map a function over a vector.
O(n) Map a function over a vector.
O(n) Map a function over a vector.
Transform this map by applying a function to every value.
Transform this set by applying a function to every value. The resulting set may be smaller than the source.
```>>> HashSet.map show (HashSet.fromList [1,2,3])
HashSet.fromList ["1","2","3"]
```
Transform the original string-like value but keep it case insensitive.
Note: You should use Data.Map.Strict instead of this module if:
• You will eventually need all the values stored.
• The stored values don't represent large virtual data structures to be lazily computed.
An efficient implementation of ordered maps from keys to values (dictionaries). These modules are intended to be imported qualified, to avoid name clashes with Prelude functions, e.g.
```import qualified Data.Map 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.
Bounds for union, intersection, and difference are as given by
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. Warning: The size of the map must not exceed maxBound::Int. Violation of this condition is not detected and if the size limit is exceeded, its behaviour is undefined. Operation comments contain the operation time complexity in the Big-O notation (http://en.wikipedia.org/wiki/Big_O_notation).
A Map from keys k to values a. The Semigroup operation for Map is union, which prefers values from the left operand. If m1 maps a key k to a value a1, and m2 maps the same key to a different value a2, then their union m1 <> m2 maps k to a1.
Not on Stackage, so not searched. Class of key-value maps
O(n). The function mapAccum 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 mapAccumRWithKey threads an accumulating argument through the map in descending order of keys.
O(n). The function mapAccumWithKey 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). Map values and separate the Left and Right results.
```let 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")])
```