---------------------------------------------------------------------------------
-{-| Module : Data.IntSet
- Copyright : (c) Daan Leijen 2002
- License : BSD-style
- Maintainer : libraries@haskell.org
- Stability : provisional
- Portability : portable
-
- An efficient implementation of integer sets.
-
- This module is intended to be imported @qualified@, to avoid name
- clashes with Prelude functions. eg.
-
- > import Data.IntSet as Set
-
- 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 set implementation (see "Set").
-
- * Chris Okasaki and Andy Gill, \"/Fast Mergeable Integer Maps/\",
- Workshop on ML, September 1998, pages 77--86, <http://www.cse.ogi.edu/~andy/pub/finite.htm>
-
- * D.R. Morrison, \"/PATRICIA -- Practical Algorithm To Retrieve Information
- Coded In Alphanumeric/\", Journal of the ACM, 15(4), October 1968, pages 514--534.
+-----------------------------------------------------------------------------
+-- |
+-- Module : Data.IntSet
+-- Copyright : (c) Daan Leijen 2002
+-- License : BSD-style
+-- Maintainer : libraries@haskell.org
+-- Stability : provisional
+-- Portability : portable
+--
+-- An efficient implementation of integer sets.
+--
+-- This module is intended to be imported @qualified@, to avoid name
+-- clashes with "Prelude" functions. eg.
+--
+-- > import Data.IntSet as Set
+--
+-- 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 set implementation (see "Data.Set").
+--
+-- * Chris Okasaki and Andy Gill, \"/Fast Mergeable Integer Maps/\",
+-- Workshop on ML, September 1998, pages 77-86,
+-- <http://www.cse.ogi.edu/~andy/pub/finite.htm>
+--
+-- * D.R. Morrison, \"/PATRICIA -- Practical Algorithm To Retrieve
+-- Information Coded In Alphanumeric/\", Journal of the ACM, 15(4),
+-- October 1968, pages 514-534.
+--
+-- 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).
+-----------------------------------------------------------------------------