-- |
-- Module : Data.FiniteMap
-- Copyright : (c) The University of Glasgow 2001
--- License : BSD-style (see the file libraries/core/LICENSE)
+-- License : BSD-style (see the file libraries/base/LICENSE)
--
-- Maintainer : libraries@haskell.org
-- Stability : provisional
-- Portability : portable
--
+-- NOTE: Data.FiniteMap is DEPRECATED, please use "Data.Map" instead.
+--
-- A finite map implementation, derived from the paper:
--- S Adams, "Efficient sets: a balancing act"
+-- /Efficient sets: a balancing act/, S. Adams,
-- Journal of functional programming 3(4) Oct 1993, pp553-562
--
--- ToDo: clean up, remove the COMPILING_GHC stuff.
---
-----------------------------------------------------------------------------
+-- ToDo: clean up, remove the COMPILING_GHC stuff.
+
-- The code is SPECIALIZEd to various highly-desirable types (e.g., Id)
-- near the end (only \tr{#ifdef COMPILING_GHC}).
#define OUTPUTABLE_key {--}
#endif
-module Data.FiniteMap (
+module Data.FiniteMap
+ {-# DEPRECATED "Please use Data.Map instead." #-}
+ (
+ -- * The @FiniteMap@ type
FiniteMap, -- abstract type
+ -- * Construction
emptyFM, unitFM, listToFM,
+ -- * Lookup operations
+ lookupFM, lookupWithDefaultFM,
+ elemFM,
+
+ -- * Adding elements
addToFM,
addToFM_C,
addListToFM,
addListToFM_C,
+
+ -- * Deleting elements
IF_NOT_GHC(delFromFM COMMA)
delListFromFM,
+ -- * Combination
plusFM,
plusFM_C,
+
+ -- * Extracting information
+ fmToList, keysFM, eltsFM,
+ sizeFM, isEmptyFM,
+
+ -- * Other operations
minusFM,
foldFM,
-
IF_NOT_GHC(intersectFM COMMA)
IF_NOT_GHC(intersectFM_C COMMA)
IF_NOT_GHC(mapFM COMMA filterFM COMMA)
- sizeFM, isEmptyFM, elemFM, lookupFM, lookupWithDefaultFM,
+ foldFM_GE, fmToList_GE, keysFM_GE, eltsFM_GE,
+ foldFM_LE, fmToList_LE, keysFM_LE, eltsFM_LE,
- fmToList, keysFM, eltsFM
+ minFM, maxFM,
#ifdef COMPILING_GHC
, bagToFM
#endif
) where
-import Prelude
+import Prelude -- necessary to get dependencies right
import Data.Maybe ( isJust )
#ifdef __GLASGOW_HASKELL__
import GHC.Base
+import Data.Typeable
+import Data.Generics.Basics
+import Data.Generics.Instances
+#endif
+
+#ifdef __HADDOCK__
+import Prelude
#endif
#ifdef COMPILING_GHC
#endif /* not GHC */
+
-- ---------------------------------------------------------------------------
-- The signature of the module
--- BUILDING
+-- | An empty 'FiniteMap'.
emptyFM :: FiniteMap key elt
+
+-- | A 'FiniteMap' containing a single mapping
unitFM :: key -> elt -> FiniteMap key elt
+
+-- | Makes a 'FiniteMap' from a list of @(key,value)@ pairs. In the
+-- case of duplicates, the last is taken
listToFM :: (Ord key OUTPUTABLE_key) => [(key,elt)] -> FiniteMap key elt
- -- In the case of duplicates, the last is taken
+
#ifdef COMPILING_GHC
bagToFM :: (Ord key OUTPUTABLE_key) => Bag (key,elt) -> FiniteMap key elt
-- In the case of duplicates, who knows which is taken
#endif
-- ADDING AND DELETING
- -- Throws away any previous binding
- -- In the list case, the items are added starting with the
- -- first one in the list
+
+-- | Adds an element to a 'FiniteMap'. Any previous mapping with the same
+-- key is overwritten.
addToFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> elt -> FiniteMap key elt
+
+-- | Adds a list of elements to a 'FiniteMap', in the order given in
+-- the list. Overwrites previous mappings.
addListToFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [(key,elt)] -> FiniteMap key elt
-- Combines with previous binding
-- In the combining function, the first argument is the "old" element,
-- while the second is the "new" one.
+
+-- | Adds an element to a 'FiniteMap'. If there is already an element
+-- with the same key, then the specified combination function is used
+-- to calculate the new value. The already present element is passed as
+-- the first argument and the new element to add as second.
addToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
-> FiniteMap key elt -> key -> elt
-> FiniteMap key elt
+
+-- | A list version of 'addToFM_C'. The elements are added in the
+-- order given in the list.
addListToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
-> FiniteMap key elt -> [(key,elt)]
-> FiniteMap key elt
- -- Deletion doesn't complain if you try to delete something
- -- which isn't there
+-- | Deletes an element from a 'FiniteMap'. If there is no element with
+-- the specified key, then the original 'FiniteMap' is returned.
delFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt
+
+-- | List version of 'delFromFM'.
delListFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [key] -> FiniteMap key elt
--- COMBINING
- -- Bindings in right argument shadow those in the left
+-- | Combine two 'FiniteMap's. Mappings in the second argument shadow
+-- those in the first.
plusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
-> FiniteMap key elt
- -- Combines bindings for the same thing with the given function
+-- | Combine two 'FiniteMap's. The specified combination function is
+-- used to calculate the new value when there are two elements with
+-- the same key.
plusFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
-> FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
-minusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
- -- (minusFM a1 a2) deletes from a1 any bindings which are bound in a2
+-- | @(minusFM a1 a2)@ deletes from @a1@ any mappings which are bound in @a2@
+minusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt1 -> FiniteMap key elt2 -> FiniteMap key elt1
+-- | @(intersectFM a1 a2)@ returns a new 'FiniteMap' containing
+-- mappings from @a1@ for which @a2@ also has a mapping with the same
+-- key.
intersectFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
+
+-- | Returns the intersection of two mappings, using the specified
+-- combination function to combine values.
intersectFM_C :: (Ord key OUTPUTABLE_key) => (elt1 -> elt2 -> elt3)
-> FiniteMap key elt1 -> FiniteMap key elt2 -> FiniteMap key elt3
sizeFM :: FiniteMap key elt -> Int
isEmptyFM :: FiniteMap key elt -> Bool
+-- | Returns 'True' if the specified @key@ has a mapping in this
+-- 'FiniteMap', or 'False' otherwise.
elemFM :: (Ord key OUTPUTABLE_key) => key -> FiniteMap key elt -> Bool
+
+-- | Looks up a key in a 'FiniteMap', returning @'Just' v@ if the key
+-- was found with value @v@, or 'Nothing' otherwise.
lookupFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> Maybe elt
+
+-- | Looks up a key in a 'FiniteMap', returning @elt@ if the specified
+-- @key@ was not found.
lookupWithDefaultFM
:: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> elt -> key -> elt
-- lookupWithDefaultFM supplies a "default" elt
-- to return for an unmapped key
-- LISTIFYING
+
+-- | Convert a 'FiniteMap' to a @[(key, elt)]@ sorted by 'Ord' key
+--
fmToList :: FiniteMap key elt -> [(key,elt)]
+
+-- | Extract the keys from a 'FiniteMap', in the order of the keys, so
+--
+-- > keysFM == map fst . fmToList
+--
keysFM :: FiniteMap key elt -> [key]
+
+-- | Extract the elements from a 'FiniteMap', in the order of the keys, so
+--
+-- > eltsFM == map snd . fmToList
+--
eltsFM :: FiniteMap key elt -> [elt]
-- ---------------------------------------------------------------------------
-- * size of left subtree is differs from size of right subtree by a
-- factor of at most \tr{sIZE_RATIO}
+-- | A mapping from @key@s to @elt@s.
data FiniteMap key elt
= EmptyFM
| Branch key elt -- Key and elt stored here
bottom = panic "emptyFM"
-}
--- #define EmptyFM (Branch _ _ IF_GHC(0#,0) _ _)
+-- #define EmptyFM (Branch _ _ IF_GHC(0#,0) _ _)
unitFM key elt = Branch key elt IF_GHC(1#,1) emptyFM emptyFM
bagToFM = foldBag plusFM (\ (k,v) -> unitFM k v) emptyFM
#endif
+instance (Show k, Show e) => Show (FiniteMap k e) where
+ showsPrec p m = showsPrec p (fmToList m)
+
+instance Functor (FiniteMap k) where
+ fmap f = mapFM (const f)
+
+#if __GLASGOW_HASKELL__
+
+#include "Typeable.h"
+INSTANCE_TYPEABLE2(FiniteMap,arrayTc,"FiniteMap")
+
+-- This instance preserves data abstraction at the cost of inefficiency.
+-- We omit reflection services for the sake of data abstraction.
+
+instance (Data a, Data b, Ord a) => Data (FiniteMap a b) where
+ gfoldl f z fm = z listToFM `f` (fmToList fm)
+ toConstr _ = error "toConstr"
+ gunfold _ _ = error "gunfold"
+ dataTypeOf _ = mkNorepType "Data.FiniteMap.FiniteMap"
+
+#endif
+
-- ---------------------------------------------------------------------------
-- Adding to and deleting from @FiniteMaps@
-- ---------------------------------------------------------------------------
+-- Bulk operations on all keys >= or <= a certain threshold
+
+-- | Fold through all elements greater than or equal to the supplied key,
+-- in increasing order.
+foldFM_GE :: Ord key => (key -> elt -> a -> a) -> a -> key ->
+ FiniteMap key elt -> a
+
+foldFM_GE k z fr EmptyFM = z
+foldFM_GE k z fr (Branch key elt _ fm_l fm_r)
+ | key >= fr = foldFM_GE k (k key elt (foldFM_GE k z fr fm_r)) fr fm_l
+ | otherwise = foldFM_GE k z fr fm_r
+
+-- | List elements greater than or equal to the supplied key, in increasing
+-- order
+fmToList_GE :: Ord key => FiniteMap key elt -> key -> [(key,elt)]
+fmToList_GE fm fr = foldFM_GE (\ key elt rest -> (key,elt) : rest) [] fr fm
+
+-- | List keys greater than or equal to the supplied key, in increasing order
+keysFM_GE :: Ord key => FiniteMap key elt -> key -> [key]
+keysFM_GE fm fr = foldFM_GE (\ key elt rest -> key : rest) [] fr fm
+
+-- | List elements corresponding to keys greater than or equal to the supplied
+-- key, in increasing order of key.
+eltsFM_GE :: Ord key => FiniteMap key elt -> key -> [elt]
+eltsFM_GE fm fr = foldFM_GE (\ key elt rest -> elt : rest) [] fr fm
+
+-- | Fold through all elements less than or equal to the supplied key,
+-- in decreasing order.
+foldFM_LE :: Ord key => (key -> elt -> a -> a) -> a -> key ->
+ FiniteMap key elt -> a
+foldFM_LE k z fr EmptyFM = z
+foldFM_LE k z fr (Branch key elt _ fm_l fm_r)
+ | key <= fr = foldFM_LE k (k key elt (foldFM_LE k z fr fm_l)) fr fm_r
+ | otherwise = foldFM_LE k z fr fm_l
+
+-- | List elements greater than or equal to the supplied key, in decreasing
+-- order
+fmToList_LE :: Ord key => FiniteMap key elt -> key -> [(key,elt)]
+fmToList_LE fm fr = foldFM_LE (\ key elt rest -> (key,elt) : rest) [] fr fm
+
+-- | List keys greater than or equal to the supplied key, in decreasing order
+keysFM_LE :: Ord key => FiniteMap key elt -> key -> [key]
+keysFM_LE fm fr = foldFM_LE (\ key elt rest -> key : rest) [] fr fm
+
+-- | List elements corresponding to keys greater than or equal to the supplied
+-- key, in decreasing order of key.
+eltsFM_LE :: Ord key => FiniteMap key elt -> key -> [elt]
+eltsFM_LE fm fr = foldFM_LE (\ key elt rest -> elt : rest) [] fr fm
+
+-- ---------------------------------------------------------------------------
+-- Getting minimum and maximum key out.
+-- ---------------------------------------------------------------------------
+
+-- | Extract minimum key, or Nothing if the map is empty.
+minFM :: Ord key => FiniteMap key elt -> Maybe key
+minFM EmptyFM = Nothing
+minFM (Branch key _ _ fm_l _) =
+ case minFM fm_l of
+ Nothing -> Just key
+ Just key1 -> Just key1
+
+-- | Extract maximum key, or Nothing if the map is empty.
+maxFM :: Ord key => FiniteMap key elt -> Maybe key
+maxFM EmptyFM = Nothing
+maxFM (Branch key _ _ _ fm_r) =
+ case maxFM fm_r of
+ Nothing -> Just key
+ Just key1 -> Just key1
+
+
+-- ---------------------------------------------------------------------------
-- The implementation of balancing
-- Basic construction of a @FiniteMap@:
IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt)
#-}
-#endif {- compiling for GHC -}
+#endif /* compiling for GHC */
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