Set and Map from lazy/infinite lists. https://github.com/happyherp/lazyset
|Latest on Hackage:||0.1.0.0|
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A Lazy Set and Map implemented in Haskell.
Allows efficient, lazy lookups on sorted lists. The list may be of ininite size.
The Source-List must + contain elements that implement Ord + must be ascending (or descending: see fromDescList) + either produce an infinite number of elements or terminate
Set Sample usage
import Data.Set.Lazy set = fromAscList $ map (*3) [1..] 3 `member` set -> True 4 `member` set -> False
Map Sample usage
import Prelude hiding(lookup) import Data.Map.Lazier sqrtmap = fromList $ map (\i->(i, sqrt i)) [1..] lookup 2 sqrtmap -> Just 1.4142135623730951
Elements from the Source-List will be requested in batches of increasing size. By default the batch-size is increases by two. This would lead to batches of 1,2,4,8,16. This can be changed by using growFromAscList factor list. For Example a factor of 1.3 casues the batches to be 1,2,2,3,3,4,5.
Increasing the growth-factor reduces lookup times but increases the batch-size. When it is set to 1.0 it performs like a list.
lookup: O(m) = log m where m is the index of the element in the source-list.
This breaks the set, because the underlying list stops producing elements.
set = fromList $ filter (<4) [1..] 5 `member` set
Revision history for lazyset
0.1.0.0 -- YYYY-mm-dd
- First version. Released on an unsuspecting world.
- Import of files from https://github.com/happyherp/littlethings/tree/master/euler
- making this a cabal-module