{-# OPTIONS -cpp -fglasgow-exts #-}
---------------------------------------------------------------------------------
-{-| Module : Data.IntMap
- Copyright : (c) Daan Leijen 2002
- License : BSD-style
- Maintainer : libraries@haskell.org
- Stability : provisional
- Portability : portable
-
- An efficient implementation of maps from integer keys to values.
-
- This module is intended to be imported @qualified@, to avoid name
- clashes with Prelude functions. eg.
-
- > import Data.IntMap as Map
-
- 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 "Map" and "Data.FiniteMap").
-
- * 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.IntMap
+-- Copyright : (c) Daan Leijen 2002
+-- License : BSD-style
+-- Maintainer : libraries@haskell.org
+-- Stability : provisional
+-- Portability : portable
+--
+-- An efficient implementation of maps from integer keys to values.
+--
+-- This module is intended to be imported @qualified@, to avoid name
+-- clashes with "Prelude" functions. eg.
+--
+-- > import Data.IntMap as Map
+--
+-- 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" and "Data.FiniteMap").
+--
+-- * 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).
+-----------------------------------------------------------------------------
- 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 (
-- * Map type
IntMap, Key -- instance Eq,Show
import Data.Int
import Data.Monoid
import qualified Data.IntSet as IntSet
+import Data.Typeable
{-
-- just for testing
import qualified List
-}
-#ifdef __GLASGOW_HASKELL__
-{--------------------------------------------------------------------
- GHC: use unboxing to get @shiftRL@ inlined.
---------------------------------------------------------------------}
+#if __GLASGOW_HASKELL__
+import Data.Generics.Basics
+import Data.Generics.Instances
+#endif
+
#if __GLASGOW_HASKELL__ >= 503
import GHC.Word
import GHC.Exts ( Word(..), Int(..), shiftRL# )
-#else
+#elif __GLASGOW_HASKELL__
import Word
import GlaExts ( Word(..), Int(..), shiftRL# )
+#else
+import Data.Word
#endif
infixl 9 \\{-This comment teaches CPP correct behaviour -}
+-- A "Nat" is a natural machine word (an unsigned Int)
type Nat = Word
natFromInt :: Key -> Nat
intFromNat w = fromIntegral w
shiftRL :: Nat -> Key -> Nat
-shiftRL (W# x) (I# i)
- = W# (shiftRL# x i)
-
-#elif __HUGS__
+#if __GLASGOW_HASKELL__
{--------------------------------------------------------------------
- Hugs:
- * raises errors on boundary values when using 'fromIntegral'
- but not with the deprecated 'fromInt/toInt'.
- * Older Hugs doesn't define 'Word'.
- * Newer Hugs defines 'Word' in the Prelude but no operations.
+ GHC: use unboxing to get @shiftRL@ inlined.
--------------------------------------------------------------------}
-import Data.Word
-infixl 9 \\
-
-type Nat = Word32 -- illegal on 64-bit platforms!
-
-natFromInt :: Key -> Nat
-natFromInt i = fromInt i
-
-intFromNat :: Nat -> Key
-intFromNat w = toInt w
-
-shiftRL :: Nat -> Key -> Nat
-shiftRL x i = shiftR x i
-
+shiftRL (W# x) (I# i)
+ = W# (shiftRL# x i)
#else
-{--------------------------------------------------------------------
- 'Standard' Haskell
- * A "Nat" is a natural machine word (an unsigned Int)
---------------------------------------------------------------------}
-import Data.Word
-infixl 9 \\
-
-type Nat = Word
-
-natFromInt :: Key -> Nat
-natFromInt i = fromIntegral i
-
-intFromNat :: Nat -> Key
-intFromNat w = fromIntegral w
-
-shiftRL :: Nat -> Key -> Nat
-shiftRL w i = shiftR w i
-
+shiftRL x i = shiftR x i
#endif
-
{--------------------------------------------------------------------
Operators
--------------------------------------------------------------------}
type Key = Int
{--------------------------------------------------------------------
+ A Data instance
+--------------------------------------------------------------------}
+
+#if __GLASGOW_HASKELL__
+
+-- This instance preserves data abstraction at the cost of inefficiency.
+-- We omit reflection services for the sake of data abstraction.
+
+instance Data a => Data (IntMap a) where
+ gfoldl f z im = z fromList `f` (toList im)
+ toConstr _ = error "toConstr"
+ gunfold _ _ = error "gunfold"
+ dataTypeOf _ = mkNorepType "Data.IntMap.IntMap"
+
+#endif
+
+{--------------------------------------------------------------------
Query
--------------------------------------------------------------------}
-- | /O(1)/. Is the map empty?
showElem (k,x) = shows k . showString ":=" . shows x
{--------------------------------------------------------------------
+ Typeable
+--------------------------------------------------------------------}
+
+#include "Typeable.h"
+INSTANCE_TYPEABLE1(IntMap,intMapTc,"IntMap")
+
+{--------------------------------------------------------------------
Debugging
--------------------------------------------------------------------}
-- | /O(n)/. Show the tree that implements the map. The tree is shown
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