----------------------------------------------------------------------------- -- | -- Module : FiniteMap -- Copyright : (c) The University of Glasgow 2001 -- 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: -- /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. -- The code is SPECIALIZEd to various highly-desirable types (e.g., Id) -- near the end (only \tr{#ifdef COMPILING_GHC}). #ifdef COMPILING_GHC #include "HsVersions.h" #define IF_NOT_GHC(a) {--} #else #define ASSERT(e) {--} #define IF_NOT_GHC(a) a #define COMMA , #define _tagCmp compare #define _LT LT #define _GT GT #define _EQ EQ #endif #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)/* NB NB NB */ #define OUTPUTABLE_key , Outputable key #else #define OUTPUTABLE_key {--} #endif module FiniteMap1 ( -- * 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) foldFM_GE, fmToList_GE, keysFM_GE, eltsFM_GE, foldFM_LE, fmToList_LE, keysFM_LE, eltsFM_LE, minFM, maxFM, #ifdef COMPILING_GHC , bagToFM #endif ) where 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 IMP_Ubiq(){-uitous-} # ifdef DEBUG import Pretty # endif import Bag ( foldBag ) # if ! OMIT_NATIVE_CODEGEN # define IF_NCG(a) a # else # define IF_NCG(a) {--} # endif #endif -- SIGH: but we use unboxed "sizes"... #if __GLASGOW_HASKELL__ #define IF_GHC(a,b) a #else /* not GHC */ #define IF_GHC(a,b) b #endif /* not GHC */ -- --------------------------------------------------------------------------- -- The signature of the module -- | 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 #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 -- | 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 -- | 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 -- | 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 -- | 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 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 -- MAPPING, FOLDING, FILTERING foldFM :: (key -> elt -> a -> a) -> a -> FiniteMap key elt -> a mapFM :: (key -> elt1 -> elt2) -> FiniteMap key elt1 -> FiniteMap key elt2 filterFM :: (Ord key OUTPUTABLE_key) => (key -> elt -> Bool) -> FiniteMap key elt -> FiniteMap key elt -- INTERROGATING 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] -- --------------------------------------------------------------------------- -- The @FiniteMap@ data type, and building of same -- Invariants about @FiniteMap@: -- -- * all keys in a FiniteMap are distinct -- -- * all keys in left subtree are $<$ key in Branch and -- all keys in right subtree are $>$ key in Branch -- -- * size field of a Branch gives number of Branch nodes in the tree -- -- * 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 IF_GHC(Int#,Int{-STRICT-}) -- Size >= 1 (FiniteMap key elt) -- Children (FiniteMap key elt) emptyFM = EmptyFM {- emptyFM = Branch bottom bottom IF_GHC(0#,0) bottom bottom where bottom = panic "emptyFM" -} -- #define EmptyFM (Branch _ _ IF_GHC(0#,0) _ _) unitFM key elt = Branch key elt IF_GHC(1#,1) emptyFM emptyFM listToFM = addListToFM emptyFM #ifdef COMPILING_GHC 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@ addToFM fm key elt = addToFM_C (\ old new -> new) fm key elt addToFM_C combiner EmptyFM key elt = unitFM key elt addToFM_C combiner (Branch key elt size fm_l fm_r) new_key new_elt #ifdef __GLASGOW_HASKELL__ = case _tagCmp new_key key of _LT -> mkBalBranch key elt (addToFM_C combiner fm_l new_key new_elt) fm_r _GT -> mkBalBranch key elt fm_l (addToFM_C combiner fm_r new_key new_elt) _EQ -> Branch new_key (combiner elt new_elt) size fm_l fm_r #else | new_key < key = mkBalBranch key elt (addToFM_C combiner fm_l new_key new_elt) fm_r | new_key > key = mkBalBranch key elt fm_l (addToFM_C combiner fm_r new_key new_elt) | otherwise = Branch new_key (combiner elt new_elt) size fm_l fm_r #endif addListToFM fm key_elt_pairs = addListToFM_C (\ old new -> new) fm key_elt_pairs addListToFM_C combiner fm key_elt_pairs = foldl add fm key_elt_pairs -- foldl adds from the left where add fmap (key,elt) = addToFM_C combiner fmap key elt delFromFM EmptyFM del_key = emptyFM delFromFM (Branch key elt size fm_l fm_r) del_key #if __GLASGOW_HASKELL__ = case _tagCmp del_key key of _GT -> mkBalBranch key elt fm_l (delFromFM fm_r del_key) _LT -> mkBalBranch key elt (delFromFM fm_l del_key) fm_r _EQ -> glueBal fm_l fm_r #else | del_key > key = mkBalBranch key elt fm_l (delFromFM fm_r del_key) | del_key < key = mkBalBranch key elt (delFromFM fm_l del_key) fm_r | key == del_key = glueBal fm_l fm_r #endif delListFromFM fm keys = foldl delFromFM fm keys -- --------------------------------------------------------------------------- -- Combining @FiniteMaps@ plusFM_C combiner EmptyFM fm2 = fm2 plusFM_C combiner fm1 EmptyFM = fm1 plusFM_C combiner fm1 (Branch split_key elt2 _ left right) = mkVBalBranch split_key new_elt (plusFM_C combiner lts left) (plusFM_C combiner gts right) where lts = splitLT fm1 split_key gts = splitGT fm1 split_key new_elt = case lookupFM fm1 split_key of Nothing -> elt2 Just elt1 -> combiner elt1 elt2 -- It's worth doing plusFM specially, because we don't need -- to do the lookup in fm1. plusFM EmptyFM fm2 = fm2 plusFM fm1 EmptyFM = fm1 plusFM fm1 (Branch split_key elt1 _ left right) = mkVBalBranch split_key elt1 (plusFM lts left) (plusFM gts right) where lts = splitLT fm1 split_key gts = splitGT fm1 split_key minusFM EmptyFM fm2 = emptyFM minusFM fm1 EmptyFM = fm1 minusFM fm1 (Branch split_key elt _ left right) = glueVBal (minusFM lts left) (minusFM gts right) -- The two can be way different, so we need glueVBal where lts = splitLT fm1 split_key -- NB gt and lt, so the equal ones gts = splitGT fm1 split_key -- are not in either. intersectFM fm1 fm2 = intersectFM_C (\ left right -> right) fm1 fm2 intersectFM_C combiner fm1 EmptyFM = emptyFM intersectFM_C combiner EmptyFM fm2 = emptyFM intersectFM_C combiner fm1 (Branch split_key elt2 _ left right) | isJust maybe_elt1 -- split_elt *is* in intersection = mkVBalBranch split_key (combiner elt1 elt2) (intersectFM_C combiner lts left) (intersectFM_C combiner gts right) | otherwise -- split_elt is *not* in intersection = glueVBal (intersectFM_C combiner lts left) (intersectFM_C combiner gts right) where lts = splitLT fm1 split_key -- NB gt and lt, so the equal ones gts = splitGT fm1 split_key -- are not in either. maybe_elt1 = lookupFM fm1 split_key Just elt1 = maybe_elt1 -- --------------------------------------------------------------------------- -- Mapping, folding, and filtering with @FiniteMaps@ foldFM k z EmptyFM = z foldFM k z (Branch key elt _ fm_l fm_r) = foldFM k (k key elt (foldFM k z fm_r)) fm_l mapFM f EmptyFM = emptyFM mapFM f (Branch key elt size fm_l fm_r) = Branch key (f key elt) size (mapFM f fm_l) (mapFM f fm_r) filterFM p EmptyFM = emptyFM filterFM p (Branch key elt _ fm_l fm_r) | p key elt -- Keep the item = mkVBalBranch key elt (filterFM p fm_l) (filterFM p fm_r) | otherwise -- Drop the item = glueVBal (filterFM p fm_l) (filterFM p fm_r) -- --------------------------------------------------------------------------- -- Interrogating @FiniteMaps@ --{-# INLINE sizeFM #-} sizeFM EmptyFM = 0 sizeFM (Branch _ _ size _ _) = IF_GHC(I# size, size) isEmptyFM fm = sizeFM fm == 0 lookupFM EmptyFM key = Nothing lookupFM (Branch key elt _ fm_l fm_r) key_to_find #if __GLASGOW_HASKELL__ = case _tagCmp key_to_find key of _LT -> lookupFM fm_l key_to_find _GT -> lookupFM fm_r key_to_find _EQ -> Just elt #else | key_to_find < key = lookupFM fm_l key_to_find | key_to_find > key = lookupFM fm_r key_to_find | otherwise = Just elt #endif key `elemFM` fm = case (lookupFM fm key) of { Nothing -> False; Just elt -> True } lookupWithDefaultFM fm deflt key = case (lookupFM fm key) of { Nothing -> deflt; Just elt -> elt } -- --------------------------------------------------------------------------- -- Listifying @FiniteMaps@ fmToList fm = foldFM (\ key elt rest -> (key,elt) : rest) [] fm keysFM fm = foldFM (\ key elt rest -> key : rest) [] fm eltsFM fm = foldFM (\ key elt rest -> elt : rest) [] fm -- --------------------------------------------------------------------------- -- 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@: -- @mkBranch@ simply gets the size component right. This is the ONLY -- (non-trivial) place the Branch object is built, so the ASSERTion -- recursively checks consistency. (The trivial use of Branch is in -- @unitFM@.) sIZE_RATIO :: Int sIZE_RATIO = 5 mkBranch :: (Ord key OUTPUTABLE_key) -- Used for the assertion checking only => Int -> key -> elt -> FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt mkBranch which key elt fm_l fm_r = --ASSERT( left_ok && right_ok && balance_ok ) #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS) if not ( left_ok && right_ok && balance_ok ) then pprPanic ("mkBranch:"++show which) (ppAboves [ppr PprDebug [left_ok, right_ok, balance_ok], ppr PprDebug key, ppr PprDebug fm_l, ppr PprDebug fm_r]) else #endif let result = Branch key elt (unbox (1 + left_size + right_size)) fm_l fm_r in -- if sizeFM result <= 8 then result -- else -- pprTrace ("mkBranch:"++(show which)) (ppr PprDebug result) ( -- result -- ) where left_ok = case fm_l of EmptyFM -> True Branch left_key _ _ _ _ -> let biggest_left_key = fst (findMax fm_l) in biggest_left_key < key right_ok = case fm_r of EmptyFM -> True Branch right_key _ _ _ _ -> let smallest_right_key = fst (findMin fm_r) in key < smallest_right_key balance_ok = True -- sigh {- LATER: balance_ok = -- Both subtrees have one or no elements... (left_size + right_size <= 1) -- NO || left_size == 0 -- ??? -- NO || right_size == 0 -- ??? -- ... or the number of elements in a subtree does not exceed -- sIZE_RATIO times the number of elements in the other subtree || (left_size * sIZE_RATIO >= right_size && right_size * sIZE_RATIO >= left_size) -} left_size = sizeFM fm_l right_size = sizeFM fm_r #if __GLASGOW_HASKELL__ unbox :: Int -> Int# unbox (I# size) = size #else unbox :: Int -> Int unbox x = x #endif -- --------------------------------------------------------------------------- -- {\em Balanced} construction of a @FiniteMap@ -- @mkBalBranch@ rebalances, assuming that the subtrees aren't too far -- out of whack. mkBalBranch :: (Ord key OUTPUTABLE_key) => key -> elt -> FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt mkBalBranch key elt fm_L fm_R | size_l + size_r < 2 = mkBranch 1{-which-} key elt fm_L fm_R | size_r > sIZE_RATIO * size_l -- Right tree too big = case fm_R of Branch _ _ _ fm_rl fm_rr | sizeFM fm_rl < 2 * sizeFM fm_rr -> single_L fm_L fm_R | otherwise -> double_L fm_L fm_R -- Other case impossible | size_l > sIZE_RATIO * size_r -- Left tree too big = case fm_L of Branch _ _ _ fm_ll fm_lr | sizeFM fm_lr < 2 * sizeFM fm_ll -> single_R fm_L fm_R | otherwise -> double_R fm_L fm_R -- Other case impossible | otherwise -- No imbalance = mkBranch 2{-which-} key elt fm_L fm_R where size_l = sizeFM fm_L size_r = sizeFM fm_R single_L fm_l (Branch key_r elt_r _ fm_rl fm_rr) = mkBranch 3{-which-} key_r elt_r (mkBranch 4{-which-} key elt fm_l fm_rl) fm_rr double_L fm_l (Branch key_r elt_r _ (Branch key_rl elt_rl _ fm_rll fm_rlr) fm_rr) = mkBranch 5{-which-} key_rl elt_rl (mkBranch 6{-which-} key elt fm_l fm_rll) (mkBranch 7{-which-} key_r elt_r fm_rlr fm_rr) single_R (Branch key_l elt_l _ fm_ll fm_lr) fm_r = mkBranch 8{-which-} key_l elt_l fm_ll (mkBranch 9{-which-} key elt fm_lr fm_r) double_R (Branch key_l elt_l _ fm_ll (Branch key_lr elt_lr _ fm_lrl fm_lrr)) fm_r = mkBranch 10{-which-} key_lr elt_lr (mkBranch 11{-which-} key_l elt_l fm_ll fm_lrl) (mkBranch 12{-which-} key elt fm_lrr fm_r) mkVBalBranch :: (Ord key OUTPUTABLE_key) => key -> elt -> FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt -- Assert: in any call to (mkVBalBranch_C comb key elt l r), -- (a) all keys in l are < all keys in r -- (b) all keys in l are < key -- (c) all keys in r are > key mkVBalBranch key elt EmptyFM fm_r = addToFM fm_r key elt mkVBalBranch key elt fm_l EmptyFM = addToFM fm_l key elt mkVBalBranch key elt fm_l@(Branch key_l elt_l _ fm_ll fm_lr) fm_r@(Branch key_r elt_r _ fm_rl fm_rr) | sIZE_RATIO * size_l < size_r = mkBalBranch key_r elt_r (mkVBalBranch key elt fm_l fm_rl) fm_rr | sIZE_RATIO * size_r < size_l = mkBalBranch key_l elt_l fm_ll (mkVBalBranch key elt fm_lr fm_r) | otherwise = mkBranch 13{-which-} key elt fm_l fm_r where size_l = sizeFM fm_l size_r = sizeFM fm_r -- --------------------------------------------------------------------------- -- Gluing two trees together -- @glueBal@ assumes its two arguments aren't too far out of whack, just -- like @mkBalBranch@. But: all keys in first arg are $<$ all keys in -- second. glueBal :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt glueBal EmptyFM fm2 = fm2 glueBal fm1 EmptyFM = fm1 glueBal fm1 fm2 -- The case analysis here (absent in Adams' program) is really to deal -- with the case where fm2 is a singleton. Then deleting the minimum means -- we pass an empty tree to mkBalBranch, which breaks its invariant. | sizeFM fm2 > sizeFM fm1 = mkBalBranch mid_key2 mid_elt2 fm1 (deleteMin fm2) | otherwise = mkBalBranch mid_key1 mid_elt1 (deleteMax fm1) fm2 where (mid_key1, mid_elt1) = findMax fm1 (mid_key2, mid_elt2) = findMin fm2 -- @glueVBal@ copes with arguments which can be of any size. -- But: all keys in first arg are $<$ all keys in second. glueVBal :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt glueVBal EmptyFM fm2 = fm2 glueVBal fm1 EmptyFM = fm1 glueVBal fm_l@(Branch key_l elt_l _ fm_ll fm_lr) fm_r@(Branch key_r elt_r _ fm_rl fm_rr) | sIZE_RATIO * size_l < size_r = mkBalBranch key_r elt_r (glueVBal fm_l fm_rl) fm_rr | sIZE_RATIO * size_r < size_l = mkBalBranch key_l elt_l fm_ll (glueVBal fm_lr fm_r) | otherwise -- We now need the same two cases as in glueBal above. = glueBal fm_l fm_r where size_l = sizeFM fm_l size_r = sizeFM fm_r -- --------------------------------------------------------------------------- -- Local utilities splitLT, splitGT :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt -- splitLT fm split_key = fm restricted to keys < split_key -- splitGT fm split_key = fm restricted to keys > split_key splitLT EmptyFM split_key = emptyFM splitLT (Branch key elt _ fm_l fm_r) split_key #if __GLASGOW_HASKELL__ = case _tagCmp split_key key of _LT -> splitLT fm_l split_key _GT -> mkVBalBranch key elt fm_l (splitLT fm_r split_key) _EQ -> fm_l #else | split_key < key = splitLT fm_l split_key | split_key > key = mkVBalBranch key elt fm_l (splitLT fm_r split_key) | otherwise = fm_l #endif splitGT EmptyFM split_key = emptyFM splitGT (Branch key elt _ fm_l fm_r) split_key #if __GLASGOW_HASKELL__ = case _tagCmp split_key key of _GT -> splitGT fm_r split_key _LT -> mkVBalBranch key elt (splitGT fm_l split_key) fm_r _EQ -> fm_r #else | split_key > key = splitGT fm_r split_key | split_key < key = mkVBalBranch key elt (splitGT fm_l split_key) fm_r | otherwise = fm_r #endif findMin :: FiniteMap key elt -> (key,elt) findMin (Branch key elt _ EmptyFM _) = (key,elt) findMin (Branch key elt _ fm_l _) = findMin fm_l deleteMin :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt deleteMin (Branch key elt _ EmptyFM fm_r) = fm_r deleteMin (Branch key elt _ fm_l fm_r) = mkBalBranch key elt (deleteMin fm_l) fm_r findMax :: FiniteMap key elt -> (key,elt) findMax (Branch key elt _ _ EmptyFM) = (key,elt) findMax (Branch key elt _ _ fm_r) = findMax fm_r deleteMax :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt deleteMax (Branch key elt _ fm_l EmptyFM) = fm_l deleteMax (Branch key elt _ fm_l fm_r) = mkBalBranch key elt fm_l (deleteMax fm_r) -- --------------------------------------------------------------------------- -- Output-ery #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS) instance (Outputable key) => Outputable (FiniteMap key elt) where ppr sty fm = pprX sty fm pprX sty EmptyFM = ppChar '!' pprX sty (Branch key elt sz fm_l fm_r) = ppBesides [ppLparen, pprX sty fm_l, ppSP, ppr sty key, ppSP, ppInt (IF_GHC(I# sz, sz)), ppSP, pprX sty fm_r, ppRparen] #endif #ifndef COMPILING_GHC instance (Eq key, Eq elt) => Eq (FiniteMap key elt) where fm_1 == fm_2 = (sizeFM fm_1 == sizeFM fm_2) && -- quick test (fmToList fm_1 == fmToList fm_2) {- NO: not clear what The Right Thing to do is: instance (Ord key, Ord elt) => Ord (FiniteMap key elt) where fm_1 <= fm_2 = (sizeFM fm_1 <= sizeFM fm_2) && -- quick test (fmToList fm_1 <= fmToList fm_2) -} #endif -- --------------------------------------------------------------------------- -- Efficiency pragmas for GHC -- When the FiniteMap module is used in GHC, we specialise it for -- \tr{Uniques}, for dastardly efficiency reasons. #if defined(COMPILING_GHC) && __GLASGOW_HASKELL__ && !defined(REALLY_HASKELL_1_3) {-# SPECIALIZE addListToFM :: FiniteMap (FAST_STRING, FAST_STRING) elt -> [((FAST_STRING, FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) elt , FiniteMap RdrName elt -> [(RdrName,elt)] -> FiniteMap RdrName elt IF_NCG(COMMA FiniteMap Reg elt -> [(Reg COMMA elt)] -> FiniteMap Reg elt) #-} {-# SPECIALIZE addListToFM_C :: (elt -> elt -> elt) -> FiniteMap TyCon elt -> [(TyCon,elt)] -> FiniteMap TyCon elt , (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> [(FAST_STRING,elt)] -> FiniteMap FAST_STRING elt IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> [(Reg COMMA elt)] -> FiniteMap Reg elt) #-} {-# SPECIALIZE addToFM :: FiniteMap CLabel elt -> CLabel -> elt -> FiniteMap CLabel elt , FiniteMap FAST_STRING elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt , FiniteMap (FAST_STRING, FAST_STRING) elt -> (FAST_STRING, FAST_STRING) -> elt -> FiniteMap (FAST_STRING, FAST_STRING) elt , FiniteMap RdrName elt -> RdrName -> elt -> FiniteMap RdrName elt , FiniteMap OrigName elt -> OrigName -> elt -> FiniteMap OrigName elt IF_NCG(COMMA FiniteMap Reg elt -> Reg -> elt -> FiniteMap Reg elt) #-} {-# SPECIALIZE addToFM_C :: (elt -> elt -> elt) -> FiniteMap (RdrName, RdrName) elt -> (RdrName, RdrName) -> elt -> FiniteMap (RdrName, RdrName) elt , (elt -> elt -> elt) -> FiniteMap (OrigName, OrigName) elt -> (OrigName, OrigName) -> elt -> FiniteMap (OrigName, OrigName) elt , (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> Reg -> elt -> FiniteMap Reg elt) #-} {-# SPECIALIZE bagToFM :: Bag (FAST_STRING,elt) -> FiniteMap FAST_STRING elt #-} {-# SPECIALIZE delListFromFM :: FiniteMap RdrName elt -> [RdrName] -> FiniteMap RdrName elt , FiniteMap OrigName elt -> [OrigName] -> FiniteMap OrigName elt , FiniteMap FAST_STRING elt -> [FAST_STRING] -> FiniteMap FAST_STRING elt IF_NCG(COMMA FiniteMap Reg elt -> [Reg] -> FiniteMap Reg elt) #-} {-# SPECIALIZE listToFM :: [([Char],elt)] -> FiniteMap [Char] elt , [(FAST_STRING,elt)] -> FiniteMap FAST_STRING elt , [((FAST_STRING,FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) elt , [(OrigName,elt)] -> FiniteMap OrigName elt IF_NCG(COMMA [(Reg COMMA elt)] -> FiniteMap Reg elt) #-} {-# SPECIALIZE lookupFM :: FiniteMap CLabel elt -> CLabel -> Maybe elt , FiniteMap [Char] elt -> [Char] -> Maybe elt , FiniteMap FAST_STRING elt -> FAST_STRING -> Maybe elt , FiniteMap (FAST_STRING,FAST_STRING) elt -> (FAST_STRING,FAST_STRING) -> Maybe elt , FiniteMap OrigName elt -> OrigName -> Maybe elt , FiniteMap (OrigName,OrigName) elt -> (OrigName,OrigName) -> Maybe elt , FiniteMap RdrName elt -> RdrName -> Maybe elt , FiniteMap (RdrName,RdrName) elt -> (RdrName,RdrName) -> Maybe elt IF_NCG(COMMA FiniteMap Reg elt -> Reg -> Maybe elt) #-} {-# SPECIALIZE lookupWithDefaultFM :: FiniteMap FAST_STRING elt -> elt -> FAST_STRING -> elt IF_NCG(COMMA FiniteMap Reg elt -> elt -> Reg -> elt) #-} {-# SPECIALIZE plusFM :: FiniteMap RdrName elt -> FiniteMap RdrName elt -> FiniteMap RdrName elt , FiniteMap OrigName elt -> FiniteMap OrigName elt -> FiniteMap OrigName elt , FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt IF_NCG(COMMA FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt) #-} {-# SPECIALIZE plusFM_C :: (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt) #-} #endif /* compiling for GHC */