% (c) The AQUA Project, Glasgow University, 1994-1998
%
-``Finite maps'' are the heart of the compiler's
-lookup-tables/environments and its implementation of sets. Important
-stuff!
+``Finite maps'' are the heart of the compiler's lookup-tables/environments
+and its implementation of sets. Important stuff!
-This code is derived from that in the paper:
-\begin{display}
- S Adams
- "Efficient sets: a balancing act"
- Journal of functional programming 3(4) Oct 1993, pp553-562
-\end{display}
+The implementation uses @Data.Map@ from the containers package, which
+is both maintained and faster than the past implementation (see commit log).
-The code is SPECIALIZEd to various highly-desirable types (e.g., Id)
-near the end.
+The orinigal interface is being kept around. It maps directly to Data.Map,
+only ``Data.Map.union'' is left-biased and ``plusFM'' right-biased and
+``addToFM\_C'' and ``Data.Map.insertWith'' differ in the order of
+arguments of combining function.
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings
--- for details
-
module FiniteMap (
- FiniteMap, -- abstract type
-
- emptyFM, unitFM, listToFM,
+ -- * Mappings keyed from arbitrary types
+ FiniteMap, -- abstract data type
- addToFM,
- addToFM_C,
- addListToFM,
- addListToFM_C,
- delFromFM,
- delListFromFM,
+ -- ** Manipulating those mappings
+ emptyFM, unitFM, listToFM,
- plusFM,
- plusFM_C,
- minusFM,
- foldFM,
+ addToFM,
+ addToFM_C,
+ addListToFM,
+ addListToFM_C,
+ delFromFM,
+ delListFromFM,
- intersectFM,
- intersectFM_C,
- mapFM, filterFM,
+ plusFM,
+ plusFM_C,
+ minusFM,
+ foldFM,
- sizeFM, isEmptyFM, elemFM, lookupFM, lookupWithDefaultFM,
+ intersectFM,
+ intersectFM_C,
+ mapFM, filterFM,
- fmToList, keysFM, eltsFM
+ sizeFM, isEmptyFM, elemFM, lookupFM, lookupWithDefaultFM,
- , bagToFM
+ fmToList, keysFM, eltsFM,
+ bagToFM
) where
-#include "HsVersions.h"
-
-#if defined(DEBUG_FINITEMAPS)/* NB NB NB */
-#define OUTPUTABLE_key , Outputable key
-#else
-#define OUTPUTABLE_key {--}
-#endif
-
-import Maybes
-import Bag ( Bag, foldrBag )
-import Util
+import Bag ( Bag, foldrBag )
import Outputable
-#if 0
-import GHC.Exts
--- was this import only needed for I#, or does it have something
--- to do with the (not-presently-used) IF_NCG also?
-#endif
-
-import Data.List
+import qualified Data.Map as M
-#if 0
-#if ! OMIT_NATIVE_CODEGEN
-# define IF_NCG(a) a
-#else
-# define IF_NCG(a) {--}
-#endif
-#endif
\end{code}
%************************************************************************
-%* *
+%* *
\subsection{The signature of the module}
-%* *
-%************************************************************************
-
-\begin{code}
--- BUILDING
-emptyFM :: FiniteMap key elt
-unitFM :: key -> elt -> FiniteMap key elt
-listToFM :: (Ord key OUTPUTABLE_key) => [(key,elt)] -> FiniteMap key elt
- -- In the case of duplicates, the last is taken
-bagToFM :: (Ord key OUTPUTABLE_key) => Bag (key,elt) -> FiniteMap key elt
- -- In the case of duplicates, who knows which is taken
-
--- ADDING AND DELETING
- -- Throws away any previous binding
- -- In the list case, the items are added starting with the
- -- first one in the list
-addToFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> elt -> FiniteMap key elt
-addListToFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [(key,elt)] -> FiniteMap key elt
-
- -- Combines with previous binding
- -- The combining fn goes (old -> new -> new)
-addToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
- -> FiniteMap key elt -> key -> elt
- -> FiniteMap key elt
-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
-delFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt
-delListFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [key] -> FiniteMap key elt
-
--- COMBINING
- -- Bindings in right argument shadow those in the left
-plusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
- -> FiniteMap key elt
-
- -- Combines bindings for the same thing with the given function
-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
-
-intersectFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
-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
-
-elemFM :: (Ord key OUTPUTABLE_key) => key -> FiniteMap key elt -> Bool
-lookupFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> Maybe elt
-lookupWithDefaultFM
- :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> elt -> key -> elt
- -- lookupWithDefaultFM supplies a "default" elt
- -- to return for an unmapped key
-
--- LISTIFYING
-fmToList :: FiniteMap key elt -> [(key,elt)]
-keysFM :: FiniteMap key elt -> [key]
-eltsFM :: FiniteMap key elt -> [elt]
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{The @FiniteMap@ data type, and building of same}
-%* *
-%************************************************************************
-
-Invariants about @FiniteMap@:
-\begin{enumerate}
-\item
-all keys in a FiniteMap are distinct
-\item
-all keys in left subtree are $<$ key in Branch and
-all keys in right subtree are $>$ key in Branch
-\item
-size field of a Branch gives number of Branch nodes in the tree
-\item
-size of left subtree is differs from size of right subtree by a
-factor of at most \tr{sIZE_RATIO}
-\end{enumerate}
-
-\begin{code}
-data FiniteMap key elt
- = EmptyFM
- | Branch key elt -- Key and elt stored here
- {-# UNPACK #-} !Int -- Size >= 1
- (FiniteMap key elt) -- Children
- (FiniteMap key elt)
-\end{code}
-
-\begin{code}
-emptyFM = EmptyFM
-{-
-emptyFM
- = Branch bottom bottom 0 bottom bottom
- where
- bottom = panic "emptyFM"
--}
-
--- #define EmptyFM (Branch _ _ 0 _ _)
-
-unitFM key elt = Branch key elt 1 emptyFM emptyFM
-
-listToFM = addListToFM emptyFM
-
-bagToFM = foldrBag (\(k,v) fm -> addToFM fm k v) emptyFM
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Adding to and deleting from @FiniteMaps@}
-%* *
-%************************************************************************
-
-\begin{code}
-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
- = case compare 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
-
-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
-\end{code}
-
-\begin{code}
-delFromFM EmptyFM del_key = emptyFM
-delFromFM (Branch key elt size fm_l fm_r) del_key
- = case compare 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
-
-delListFromFM fm keys = foldl' delFromFM fm keys
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Combining @FiniteMaps@}
-%* *
-%************************************************************************
-
-\begin{code}
-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.
--- FM2 over-rides 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)
-
- | maybeToBool 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
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Mapping, folding, and filtering with @FiniteMaps@}
-%* *
-%************************************************************************
-
-\begin{code}
-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)
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Interrogating @FiniteMaps@}
-%* *
-%************************************************************************
-
-\begin{code}
---{-# INLINE sizeFM #-}
-sizeFM EmptyFM = 0
-sizeFM (Branch _ _ size _ _) = size
-
-isEmptyFM fm = sizeFM fm == 0
-
-lookupFM EmptyFM key = Nothing
-lookupFM (Branch key elt _ fm_l fm_r) key_to_find
- = case compare key_to_find key of
- LT -> lookupFM fm_l key_to_find
- GT -> lookupFM fm_r key_to_find
- EQ -> Just elt
-
-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 }
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Listifying @FiniteMaps@}
-%* *
-%************************************************************************
-
-\begin{code}
-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
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{The implementation of balancing}
-%* *
-%************************************************************************
-
-%************************************************************************
-%* *
-\subsubsection{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@.)
-
-\begin{code}
-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(DEBUG_FINITEMAPS)
- if not ( left_ok && right_ok && balance_ok ) then
- pprPanic ("mkBranch:"++show which) (vcat [ppr [left_ok, right_ok, balance_ok],
- ppr key,
- ppr fm_l,
- ppr fm_r])
- else
+%* *
+%************************************************************************
+
+\begin{code}
+-- BUILDING
+emptyFM :: FiniteMap key elt
+unitFM :: key -> elt -> FiniteMap key elt
+-- | In the case of duplicates keys, the last item is taken
+listToFM :: (Ord key) => [(key,elt)] -> FiniteMap key elt
+-- | In the case of duplicate keys, who knows which item is taken
+bagToFM :: (Ord key) => Bag (key,elt) -> FiniteMap key elt
+
+-- ADDING AND DELETING
+
+-- | Throws away any previous binding
+addToFM :: (Ord key)
+ => FiniteMap key elt -> key -> elt -> FiniteMap key elt
+-- | Throws away any previous binding, items are added left-to-right
+addListToFM :: (Ord key)
+ => FiniteMap key elt -> [(key,elt)] -> FiniteMap key elt
+
+-- | Combines added item with previous item, if any --
+-- if the key is present, ``addToFM_C f`` inserts
+-- ``(key, f old_value new_value)''
+addToFM_C :: (Ord key) => (elt -> elt -> elt)
+ -> FiniteMap key elt -> key -> elt
+ -> FiniteMap key elt
+-- | Combines added item with previous item, if any, items are added left-to-right
+addListToFM_C :: (Ord 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
+delFromFM :: (Ord key)
+ => FiniteMap key elt -> key -> FiniteMap key elt
+-- | Deletion doesn't complain if you try to delete something which isn't there
+delListFromFM :: (Ord key)
+ => FiniteMap key elt -> [key] -> FiniteMap key elt
+
+-- COMBINING
+
+-- | Bindings in right argument shadow those in the left
+plusFM :: (Ord key)
+ => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
+
+-- | Combines bindings for the same thing with the given function,
+-- bindings in right argument shadow those in the left
+plusFM_C :: (Ord key)
+ => (elt -> elt -> elt)
+ -> FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
+
+-- | Deletes from the left argument any bindings in the right argument
+minusFM :: (Ord key)
+ => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
+
+intersectFM :: (Ord key)
+ => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
+-- | Combines bindings for the same thing in the two maps with the given function
+intersectFM_C :: (Ord 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)
+ => (key -> elt -> Bool)
+ -> FiniteMap key elt -> FiniteMap key elt
+
+-- INTERROGATING
+sizeFM :: FiniteMap key elt -> Int
+isEmptyFM :: FiniteMap key elt -> Bool
+
+elemFM :: (Ord key)
+ => key -> FiniteMap key elt -> Bool
+lookupFM :: (Ord key)
+ => FiniteMap key elt -> key -> Maybe elt
+-- | Supplies a "default" element in return for an unmapped key
+lookupWithDefaultFM :: (Ord key)
+ => FiniteMap key elt -> elt -> key -> elt
+
+-- LISTIFYING
+fmToList :: FiniteMap key elt -> [(key,elt)]
+keysFM :: FiniteMap key elt -> [key]
+eltsFM :: FiniteMap key elt -> [elt]
+\end{code}
+
+%************************************************************************
+%* *
+\subsection{Implementation using ``Data.Map''}
+%* *
+%************************************************************************
+
+\begin{code}
+newtype FiniteMap key elt = FM (M.Map key elt)
+
+emptyFM = FM M.empty
+unitFM k v = FM (M.singleton k v)
+listToFM l = FM (M.fromList l)
+
+addToFM (FM m) k v = FM (M.insert k v m)
+-- Arguments of combining function of M.insertWith and addToFM_C are flipped.
+addToFM_C f (FM m) k v = FM (M.insertWith (flip f) k v m)
+addListToFM = foldl (\m (k, v) -> addToFM m k v)
+addListToFM_C f = foldl (\m (k, v) -> addToFM_C f m k v)
+delFromFM (FM m) k = FM (M.delete k m)
+delListFromFM = foldl delFromFM
+
+-- M.union is left-biased, plusFM should be right-biased.
+plusFM (FM x) (FM y) = FM (M.union y x)
+plusFM_C f (FM x) (FM y) = FM (M.unionWith f x y)
+minusFM (FM x) (FM y) = FM (M.difference x y)
+#if MIN_VERSION_containers(0,4,0)
+foldFM k z (FM m) = M.foldrWithKey k z m
+#else
+foldFM k z (FM m) = M.foldWithKey k z m
#endif
- let
- result = Branch key elt (1 + left_size + right_size) fm_l fm_r
- in
--- if sizeFM result <= 8 then
- result
--- else
--- pprTrace ("mkBranch:"++(show which)) (ppr 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
-\end{code}
-
-%************************************************************************
-%* *
-\subsubsection{{\em Balanced} construction of a @FiniteMap@}
-%* *
-%************************************************************************
-
-@mkBalBranch@ rebalances, assuming that the subtrees aren't too far
-out of whack.
-
-\begin{code}
-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)
-\end{code}
-
-
-\begin{code}
-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
+intersectFM (FM x) (FM y) = FM (M.intersection x y)
+intersectFM_C f (FM x) (FM y) = FM (M.intersectionWith f x y)
+mapFM f (FM m) = FM (M.mapWithKey f m)
+filterFM p (FM m) = FM (M.filterWithKey p m)
-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
+sizeFM (FM m) = M.size m
+isEmptyFM (FM m) = M.null m
+elemFM k (FM m) = M.member k m
+lookupFM (FM m) k = M.lookup k m
+lookupWithDefaultFM (FM m) v k = M.findWithDefault v k m
- | sIZE_RATIO * size_r < size_l
- = mkBalBranch key_l elt_l fm_ll (mkVBalBranch key elt fm_lr fm_r)
+fmToList (FM m) = M.toList m
+keysFM (FM m) = M.keys m
+eltsFM (FM m) = M.elems m
- | otherwise
- = mkBranch 13{-which-} key elt fm_l fm_r
+bagToFM = foldrBag (\(k,v) m -> addToFM m k v) emptyFM
- where
- size_l = sizeFM fm_l
- size_r = sizeFM fm_r
\end{code}
%************************************************************************
-%* *
-\subsubsection{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.
-
-\begin{code}
-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
-\end{code}
-
-@glueVBal@ copes with arguments which can be of any size.
-But: all keys in first arg are $<$ all keys in second.
-
-\begin{code}
-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
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Local utilities}
-%* *
-%************************************************************************
-
-\begin{code}
-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
- = case compare split_key key of
- LT -> splitLT fm_l split_key
- GT -> mkVBalBranch key elt fm_l (splitLT fm_r split_key)
- EQ -> fm_l
-
-splitGT EmptyFM split_key = emptyFM
-splitGT (Branch key elt _ fm_l fm_r) split_key
- = case compare split_key key of
- GT -> splitGT fm_r split_key
- LT -> mkVBalBranch key elt (splitGT fm_l split_key) fm_r
- EQ -> fm_r
-
-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)
-\end{code}
-
-%************************************************************************
-%* *
+%* *
\subsection{Output-ery}
-%* *
+%* *
%************************************************************************
\begin{code}
-#if defined(DEBUG_FINITEMAPS)
-
-instance (Outputable key) => Outputable (FiniteMap key elt) where
- ppr fm = pprX fm
-
-pprX EmptyFM = char '!'
-pprX (Branch key elt sz fm_l fm_r)
- = parens (hcat [pprX fm_l, space,
- ppr key, space, int sz, space,
- pprX fm_r])
-#else
--- and when not debugging the package itself...
instance (Outputable key, Outputable elt) => Outputable (FiniteMap key elt) where
ppr fm = ppr (fmToList fm)
-#endif
-
-#if 0
-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
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Efficiency pragmas for GHC}
-%* *
-%************************************************************************
-
-When the FiniteMap module is used in GHC, we specialise it for
-\tr{Uniques}, for dastardly efficiency reasons.
-
-\begin{code}
-#if 0
-
-#if __GLASGOW_HASKELL__
-
-{-# SPECIALIZE addListToFM
- :: FiniteMap (FastString, 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 FastString 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 FastString elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt
- , FiniteMap (FastString, 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 -> 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 FastString 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 (FastString,elt) -> FiniteMap FAST_STRING elt
- #-}
-{-# SPECIALIZE delListFromFM
- :: FiniteMap RdrName elt -> [RdrName] -> FiniteMap RdrName elt
- , FiniteMap FastString elt -> [FAST_STRING] -> FiniteMap FAST_STRING elt
- IF_NCG(COMMA FiniteMap Reg elt -> [Reg] -> FiniteMap Reg elt)
- #-}
-{-# SPECIALIZE listToFM
- :: [([Char],elt)] -> FiniteMap [Char] elt
- , [(FastString,elt)] -> FiniteMap FAST_STRING elt
- , [((FastString,FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) 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 FastString elt -> FAST_STRING -> Maybe elt
- , FiniteMap (FastString,FAST_STRING) elt -> (FAST_STRING,FAST_STRING) -> 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 FastString 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 FastString 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 FastString 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 with ghc and have specialiser */
-
-#endif /* 0 */
\end{code}
projects / ghc-hetmet.git / blobdiff