@hackage IntervalMap0.6.2.0

Containers for intervals, with efficient search.

IntervalMap Hackage Build Status

Containers for intervals. Like Data.Set and Data.Map with Intervals as keys and functions for efficiently getting the subset of all intervals containing a point, intersecting an interval, and more.

Home page and documentation: [http://www.chr-breitkopf.de/comp/IntervalMap/index.html](http://www.chr-breitkopf.de/comp/IntervalMap/index.html)

Getting started

Enable necessary language extensions:

{-# LANGUAGE MultiParamTypeClasses, FlexibleInstances #-}

In most cases, you should use the value-strict version:

import qualified Data.IntervalMap.Generic.Strict as IM

Make tuples an instance of Interval:

instance Ord e => IM.Interval (e,e) e where
    lowerBound (a,_) = a
    upperBound (_,b) = b
    rightClosed _ = False

By using rightClosed _ = False we have defined tuples to be half-open intervals - they include the starting value, but not the end value.

Let's create a map from (Int,Int) intervals to strings:

type MyMap = IM.IntervalMap (Int,Int) String

sample :: MyMap
sample = IM.fromList [((1,6), "Foo"), ((2,4), "Bar"), ((4,7), "Baz")]

Lookup intervals containing a given point ("stabbing query"):

> IM.toAscList (sample `IM.containing` 3)
[((1,6),"Foo"),((2,4),"Bar")]
> IM.toAscList (sample `IM.containing` 4)
[((1,6),"Foo"),((4,7),"Baz")]