Portability | portable |
---|---|

Stability | provisional |

Maintainer | libraries@haskell.org |

Safe Haskell | Trustworthy |

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).

- 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 aSource

*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. In contrast to
`insertWith`

, the value argument is not evaluted when not
needed by the combining function.

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

*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. In contrast to
`insertWithKey`

, the value argument is not evaluted when
not needed by the combining function.

foldWithKey :: (Key -> a -> b -> b) -> b -> IntMap a -> bSource

*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.