Data.IntMap

containers-0.5.5.1: Assorted concrete container types

Copyright | (c) Daan Leijen 2002 (c) Andriy Palamarchuk 2008
License | BSD-style
Maintainer | libraries@haskell.org
Stability | provisional
Portability | portable
Safe Haskell | Trustworthy
Language | Haskell98

Data.IntMap

Description

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

This module re-exports the value lazy Data.IntMap.Lazy API, plus several deprecated value strict functions. Please note that these functions have different strictness properties than those in Data.IntMap.Strict: they only evaluate the result of the combining function. For example, the default value to `insertWith'` is only evaluated if the combining function is called and uses it.

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

     import Data.IntMap (IntMap)
     import qualified Data.IntMap as IntMap

The implementation is based on big-endian patricia trees. This data structure performs especially well on binary operations like `union` and `intersection`. However, my benchmarks show that it is also (much) faster on insertions and deletions when compared to a generic size-balanced map implementation (see Data.Map).

- Chris Okasaki and Andy Gill, "Fast Mergeable Integer Maps", Workshop on ML, September 1998, pages 77-86, http://citeseer.ist.psu.edu/okasaki98fast.html
  - D.R. Morrison, "/PATRICIA -- Practical Algorithm To Retrieve Information Coded In Alphanumeric/", Journal of the ACM, 15(4), October 1968, pages 514-534.

Operation comments contain the operation time complexity in the Big-O notation http://en.wikipedia.org/wiki/Big_O_notation. Many operations have a worst-case complexity of O(min(n,W)). This means that the operation can become linear in the number of elements with a maximum of W -- the number of bits in an `Int` (32 or 64).

Synopsis

- module Data.IntMap.Lazy
- insertWith' :: (a -> a -> a) -> Key -> a -> IntMap a -> IntMap a
- insertWithKey' :: (Key -> a -> a -> a) -> Key -> a -> IntMap a -> IntMap a
- fold :: (a -> b -> b) -> b -> IntMap a -> b
- foldWithKey :: (Key -> a -> b -> b) -> b -> IntMap a -> b

# Documentation

module Data.IntMap.Lazy

insertWith' :: (a -> a -> a) -> Key -> a -> IntMap a -> IntMap a Source

Deprecated. As of version 0.5, replaced by `insertWith`.

O(log n). Same as `insertWith`, but the result of the combining function is evaluated to WHNF before inserted to the map.

insertWithKey' :: (Key -> a -> a -> a) -> Key -> a -> IntMap a -> IntMap a Source

Deprecated. As of version 0.5, replaced by `insertWithKey`.

O(log n). Same as `insertWithKey`, but the result of the combining function is evaluated to WHNF before inserted to the map.

fold :: (a -> b -> b) -> b -> IntMap a -> b Source

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 :: (Key -> a -> b -> b) -> b -> IntMap a -> b Source

Deprecated. As of version 0.5, 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.