containers-0.5.0.0: Assorted concrete container types

Portabilityportable
Stabilityprovisional
Maintainerlibraries@haskell.org
Safe HaskellSafe

Data.Map

Description

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

This module re-exports the value lazy Lazy API, plus several value strict functions from Strict.

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.

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).

Synopsis

Documentation

insertWith' :: Ord k => (a -> a -> a) -> k -> a -> Map k a -> Map k aSource

Deprecated. As of version 0.5, replaced by insertWith.

O(log n). Same as insertWith, but the combining function is applied strictly. This is often the most desirable behavior.

For example, to update a counter:

 insertWith' (+) k 1 m

insertWithKey' :: Ord k => (k -> a -> a -> a) -> k -> a -> Map k a -> Map k aSource

Deprecated. As of version 0.5, replaced by insertWithKey.

O(log n). Same as insertWithKey, but the combining function is applied strictly.

insertLookupWithKey' :: Ord k => (k -> a -> a -> a) -> k -> a -> Map k a -> (Maybe a, Map k a)Source

Deprecated. As of version 0.5, replaced by insertLookupWithKey.

O(log n). A strict version of insertLookupWithKey.

fold :: (a -> b -> b) -> b -> Map k a -> bSource

Deprecated. As of version 0.5, replaced by foldr.

O(n). Fold the values in the map using the given right-associative binary operator. This function is an equivalent of foldr and is present for compatibility only.

foldWithKey :: (k -> a -> b -> b) -> b -> Map k a -> bSource

Deprecated. As of version 0.4, replaced by foldrWithKey.

O(n). Fold the keys and values in the map using the given right-associative binary operator. This function is an equivalent of foldrWithKey and is present for compatibility only.