1 -----------------------------------------------------------------------------
3 -- Module : Data.FiniteMap
4 -- Copyright : (c) The University of Glasgow 2001
5 -- License : BSD-style (see the file libraries/base/LICENSE)
7 -- Maintainer : libraries@haskell.org
8 -- Stability : provisional
9 -- Portability : portable
11 -- A finite map implementation, derived from the paper:
12 -- /Efficient sets: a balancing act/, S. Adams,
13 -- Journal of functional programming 3(4) Oct 1993, pp553-562
15 -----------------------------------------------------------------------------
17 -- ToDo: clean up, remove the COMPILING_GHC stuff.
19 -- The code is SPECIALIZEd to various highly-desirable types (e.g., Id)
20 -- near the end (only \tr{#ifdef COMPILING_GHC}).
23 #include "HsVersions.h"
24 #define IF_NOT_GHC(a) {--}
26 #define ASSERT(e) {--}
27 #define IF_NOT_GHC(a) a
29 #define _tagCmp compare
35 #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)/* NB NB NB */
36 #define OUTPUTABLE_key , Outputable key
38 #define OUTPUTABLE_key {--}
41 module Data.FiniteMap (
42 -- * The @FiniteMap@ type
43 FiniteMap, -- abstract type
46 emptyFM, unitFM, listToFM,
48 -- * Lookup operations
49 lookupFM, lookupWithDefaultFM,
58 -- * Deleting elements
59 IF_NOT_GHC(delFromFM COMMA)
66 -- * Extracting information
67 fmToList, keysFM, eltsFM,
73 IF_NOT_GHC(intersectFM COMMA)
74 IF_NOT_GHC(intersectFM_C COMMA)
75 IF_NOT_GHC(mapFM COMMA filterFM COMMA)
77 foldFM_GE, fmToList_GE, keysFM_GE, eltsFM_GE
84 import Data.Maybe ( isJust )
85 #ifdef __GLASGOW_HASKELL__
94 import Bag ( foldBag )
96 # if ! OMIT_NATIVE_CODEGEN
99 # define IF_NCG(a) {--}
103 -- SIGH: but we use unboxed "sizes"...
104 #if __GLASGOW_HASKELL__
105 #define IF_GHC(a,b) a
107 #define IF_GHC(a,b) b
111 -- ---------------------------------------------------------------------------
112 -- The signature of the module
114 -- | An empty 'FiniteMap'.
115 emptyFM :: FiniteMap key elt
117 -- | A 'FiniteMap' containing a single mapping
118 unitFM :: key -> elt -> FiniteMap key elt
120 -- | Makes a 'FiniteMap' from a list of @(key,value)@ pairs. In the
121 -- case of duplicates, the last is taken
122 listToFM :: (Ord key OUTPUTABLE_key) => [(key,elt)] -> FiniteMap key elt
125 bagToFM :: (Ord key OUTPUTABLE_key) => Bag (key,elt) -> FiniteMap key elt
126 -- In the case of duplicates, who knows which is taken
129 -- ADDING AND DELETING
131 -- | Adds an element to a 'FiniteMap'. Any previous mapping with the same
132 -- key is overwritten.
133 addToFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> elt -> FiniteMap key elt
135 -- | Adds a list of elements to a 'FiniteMap', in the order given in
136 -- the list. Overwrites previous mappings.
137 addListToFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [(key,elt)] -> FiniteMap key elt
139 -- Combines with previous binding
140 -- In the combining function, the first argument is the "old" element,
141 -- while the second is the "new" one.
143 -- | Adds an element to a 'FiniteMap'. If there is already an element
144 -- with the same key, then the specified combination function is used
145 -- to calculate the new value. The already present element is passed as
146 -- the first argument and the new element to add as second.
147 addToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
148 -> FiniteMap key elt -> key -> elt
151 -- | A list version of 'addToFM_C'. The elements are added in the
152 -- order given in the list.
153 addListToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
154 -> FiniteMap key elt -> [(key,elt)]
157 -- | Deletes an element from a 'FiniteMap'. If there is no element with
158 -- the specified key, then the original 'FiniteMap' is returned.
159 delFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt
161 -- | List version of 'delFromFM'.
162 delListFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [key] -> FiniteMap key elt
164 -- | Combine two 'FiniteMap's. Mappings in the second argument shadow
165 -- those in the first.
166 plusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
169 -- | Combine two 'FiniteMap's. The specified combination function is
170 -- used to calculate the new value when there are two elements with
172 plusFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
173 -> FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
175 -- | @(minusFM a1 a2)@ deletes from @a1@ any mappings which are bound in @a2@
176 minusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
178 -- | @(intersectFM a1 a2)@ returns a new 'FiniteMap' containing
179 -- mappings from @a1@ for which @a2@ also has a mapping with the same
181 intersectFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
183 -- | Returns the interesction of two mappings, using the specified
184 -- combination function to combine values.
185 intersectFM_C :: (Ord key OUTPUTABLE_key) => (elt1 -> elt2 -> elt3)
186 -> FiniteMap key elt1 -> FiniteMap key elt2 -> FiniteMap key elt3
188 -- MAPPING, FOLDING, FILTERING
189 foldFM :: (key -> elt -> a -> a) -> a -> FiniteMap key elt -> a
190 mapFM :: (key -> elt1 -> elt2) -> FiniteMap key elt1 -> FiniteMap key elt2
191 filterFM :: (Ord key OUTPUTABLE_key) => (key -> elt -> Bool)
192 -> FiniteMap key elt -> FiniteMap key elt
195 sizeFM :: FiniteMap key elt -> Int
196 isEmptyFM :: FiniteMap key elt -> Bool
198 -- | Returns 'True' if the specified @key@ has a mapping in this
199 -- 'FiniteMap', or 'False' otherwise.
200 elemFM :: (Ord key OUTPUTABLE_key) => key -> FiniteMap key elt -> Bool
202 -- | Looks up a key in a 'FiniteMap', returning @'Just' v@ if the key
203 -- was found with value @v@, or 'Nothing' otherwise.
204 lookupFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> Maybe elt
206 -- | Looks up a key in a 'FiniteMap', returning @elt@ if the specified
207 -- @key@ was not found.
209 :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> elt -> key -> elt
210 -- lookupWithDefaultFM supplies a "default" elt
211 -- to return for an unmapped key
215 -- | Convert a 'FiniteMap' to a @[(key, elt)]@ sorted by 'Ord' key
217 fmToList :: FiniteMap key elt -> [(key,elt)]
219 -- | Extract the keys from a 'FiniteMap', in the order of the keys, so
221 -- > keysFM == map fst . fmToList
223 keysFM :: FiniteMap key elt -> [key]
225 -- | Extract the elements from a 'FiniteMap', in the order of the keys, so
227 -- > eltsFM == map snd . fmToList
229 eltsFM :: FiniteMap key elt -> [elt]
231 -- ---------------------------------------------------------------------------
232 -- The @FiniteMap@ data type, and building of same
234 -- Invariants about @FiniteMap@:
236 -- * all keys in a FiniteMap are distinct
238 -- * all keys in left subtree are $<$ key in Branch and
239 -- all keys in right subtree are $>$ key in Branch
241 -- * size field of a Branch gives number of Branch nodes in the tree
243 -- * size of left subtree is differs from size of right subtree by a
244 -- factor of at most \tr{sIZE_RATIO}
246 -- | A mapping from @key@s to @elt@s.
247 data FiniteMap key elt
249 | Branch key elt -- Key and elt stored here
250 IF_GHC(Int#,Int{-STRICT-}) -- Size >= 1
251 (FiniteMap key elt) -- Children
258 = Branch bottom bottom IF_GHC(0#,0) bottom bottom
260 bottom = panic "emptyFM"
263 -- #define EmptyFM (Branch _ _ IF_GHC(0#,0) _ _)
265 unitFM key elt = Branch key elt IF_GHC(1#,1) emptyFM emptyFM
267 listToFM = addListToFM emptyFM
270 bagToFM = foldBag plusFM (\ (k,v) -> unitFM k v) emptyFM
274 -- ---------------------------------------------------------------------------
275 -- Adding to and deleting from @FiniteMaps@
277 addToFM fm key elt = addToFM_C (\ old new -> new) fm key elt
279 addToFM_C combiner EmptyFM key elt = unitFM key elt
280 addToFM_C combiner (Branch key elt size fm_l fm_r) new_key new_elt
281 #ifdef __GLASGOW_HASKELL__
282 = case _tagCmp new_key key of
283 _LT -> mkBalBranch key elt (addToFM_C combiner fm_l new_key new_elt) fm_r
284 _GT -> mkBalBranch key elt fm_l (addToFM_C combiner fm_r new_key new_elt)
285 _EQ -> Branch new_key (combiner elt new_elt) size fm_l fm_r
287 | new_key < key = mkBalBranch key elt (addToFM_C combiner fm_l new_key new_elt) fm_r
288 | new_key > key = mkBalBranch key elt fm_l (addToFM_C combiner fm_r new_key new_elt)
289 | otherwise = Branch new_key (combiner elt new_elt) size fm_l fm_r
292 addListToFM fm key_elt_pairs = addListToFM_C (\ old new -> new) fm key_elt_pairs
294 addListToFM_C combiner fm key_elt_pairs
295 = foldl add fm key_elt_pairs -- foldl adds from the left
297 add fmap (key,elt) = addToFM_C combiner fmap key elt
300 delFromFM EmptyFM del_key = emptyFM
301 delFromFM (Branch key elt size fm_l fm_r) del_key
302 #if __GLASGOW_HASKELL__
303 = case _tagCmp del_key key of
304 _GT -> mkBalBranch key elt fm_l (delFromFM fm_r del_key)
305 _LT -> mkBalBranch key elt (delFromFM fm_l del_key) fm_r
306 _EQ -> glueBal fm_l fm_r
309 = mkBalBranch key elt fm_l (delFromFM fm_r del_key)
312 = mkBalBranch key elt (delFromFM fm_l del_key) fm_r
318 delListFromFM fm keys = foldl delFromFM fm keys
320 -- ---------------------------------------------------------------------------
321 -- Combining @FiniteMaps@
323 plusFM_C combiner EmptyFM fm2 = fm2
324 plusFM_C combiner fm1 EmptyFM = fm1
325 plusFM_C combiner fm1 (Branch split_key elt2 _ left right)
326 = mkVBalBranch split_key new_elt
327 (plusFM_C combiner lts left)
328 (plusFM_C combiner gts right)
330 lts = splitLT fm1 split_key
331 gts = splitGT fm1 split_key
332 new_elt = case lookupFM fm1 split_key of
334 Just elt1 -> combiner elt1 elt2
336 -- It's worth doing plusFM specially, because we don't need
337 -- to do the lookup in fm1.
339 plusFM EmptyFM fm2 = fm2
340 plusFM fm1 EmptyFM = fm1
341 plusFM fm1 (Branch split_key elt1 _ left right)
342 = mkVBalBranch split_key elt1 (plusFM lts left) (plusFM gts right)
344 lts = splitLT fm1 split_key
345 gts = splitGT fm1 split_key
347 minusFM EmptyFM fm2 = emptyFM
348 minusFM fm1 EmptyFM = fm1
349 minusFM fm1 (Branch split_key elt _ left right)
350 = glueVBal (minusFM lts left) (minusFM gts right)
351 -- The two can be way different, so we need glueVBal
353 lts = splitLT fm1 split_key -- NB gt and lt, so the equal ones
354 gts = splitGT fm1 split_key -- are not in either.
356 intersectFM fm1 fm2 = intersectFM_C (\ left right -> right) fm1 fm2
358 intersectFM_C combiner fm1 EmptyFM = emptyFM
359 intersectFM_C combiner EmptyFM fm2 = emptyFM
360 intersectFM_C combiner fm1 (Branch split_key elt2 _ left right)
362 | isJust maybe_elt1 -- split_elt *is* in intersection
363 = mkVBalBranch split_key (combiner elt1 elt2) (intersectFM_C combiner lts left)
364 (intersectFM_C combiner gts right)
366 | otherwise -- split_elt is *not* in intersection
367 = glueVBal (intersectFM_C combiner lts left) (intersectFM_C combiner gts right)
370 lts = splitLT fm1 split_key -- NB gt and lt, so the equal ones
371 gts = splitGT fm1 split_key -- are not in either.
373 maybe_elt1 = lookupFM fm1 split_key
374 Just elt1 = maybe_elt1
377 -- ---------------------------------------------------------------------------
378 -- Mapping, folding, and filtering with @FiniteMaps@
380 foldFM k z EmptyFM = z
381 foldFM k z (Branch key elt _ fm_l fm_r)
382 = foldFM k (k key elt (foldFM k z fm_r)) fm_l
384 mapFM f EmptyFM = emptyFM
385 mapFM f (Branch key elt size fm_l fm_r)
386 = Branch key (f key elt) size (mapFM f fm_l) (mapFM f fm_r)
388 filterFM p EmptyFM = emptyFM
389 filterFM p (Branch key elt _ fm_l fm_r)
390 | p key elt -- Keep the item
391 = mkVBalBranch key elt (filterFM p fm_l) (filterFM p fm_r)
393 | otherwise -- Drop the item
394 = glueVBal (filterFM p fm_l) (filterFM p fm_r)
397 -- ---------------------------------------------------------------------------
398 -- Interrogating @FiniteMaps@
400 --{-# INLINE sizeFM #-}
402 sizeFM (Branch _ _ size _ _) = IF_GHC(I# size, size)
404 isEmptyFM fm = sizeFM fm == 0
406 lookupFM EmptyFM key = Nothing
407 lookupFM (Branch key elt _ fm_l fm_r) key_to_find
408 #if __GLASGOW_HASKELL__
409 = case _tagCmp key_to_find key of
410 _LT -> lookupFM fm_l key_to_find
411 _GT -> lookupFM fm_r key_to_find
414 | key_to_find < key = lookupFM fm_l key_to_find
415 | key_to_find > key = lookupFM fm_r key_to_find
416 | otherwise = Just elt
420 = case (lookupFM fm key) of { Nothing -> False; Just elt -> True }
422 lookupWithDefaultFM fm deflt key
423 = case (lookupFM fm key) of { Nothing -> deflt; Just elt -> elt }
426 -- ---------------------------------------------------------------------------
427 -- Listifying @FiniteMaps@
429 fmToList fm = foldFM (\ key elt rest -> (key,elt) : rest) [] fm
430 keysFM fm = foldFM (\ key elt rest -> key : rest) [] fm
431 eltsFM fm = foldFM (\ key elt rest -> elt : rest) [] fm
434 -- ---------------------------------------------------------------------------
435 -- Bulk operations on all keys >= a certain threshold
437 -- | Fold through all elements greater than or equal to the supplied key,
438 -- in increasing order.
439 foldFM_GE :: Ord key => (key -> elt -> a -> a) -> a -> key ->
440 FiniteMap key elt -> a
442 foldFM_GE k z fr EmptyFM = z
443 foldFM_GE k z fr (Branch key elt _ fm_l fm_r)
444 | key >= fr = foldFM_GE k (k key elt (foldFM_GE k z fr fm_r)) fr fm_l
445 | otherwise = foldFM_GE k z fr fm_r
447 -- | List elements greater than or equal to the supplied key, in increasing
449 fmToList_GE :: Ord key => FiniteMap key elt -> key -> [(key,elt)]
450 fmToList_GE fm fr = foldFM_GE (\ key elt rest -> (key,elt) : rest) [] fr fm
452 -- | List keys greater than or equal to the supplied key, in increasing order
453 keysFM_GE :: Ord key => FiniteMap key elt -> key -> [key]
454 keysFM_GE fm fr = foldFM_GE (\ key elt rest -> key : rest) [] fr fm
456 -- | List elements corresponding to keys greater than or equal to the supplied
457 -- key, in increasing order of key.
458 eltsFM_GE :: Ord key => FiniteMap key elt -> key -> [elt]
459 eltsFM_GE fm fr = foldFM_GE (\ key elt rest -> elt : rest) [] fr fm
461 -- ---------------------------------------------------------------------------
462 -- The implementation of balancing
464 -- Basic construction of a @FiniteMap@:
466 -- @mkBranch@ simply gets the size component right. This is the ONLY
467 -- (non-trivial) place the Branch object is built, so the ASSERTion
468 -- recursively checks consistency. (The trivial use of Branch is in
474 mkBranch :: (Ord key OUTPUTABLE_key) -- Used for the assertion checking only
477 -> FiniteMap key elt -> FiniteMap key elt
480 mkBranch which key elt fm_l fm_r
481 = --ASSERT( left_ok && right_ok && balance_ok )
482 #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)
483 if not ( left_ok && right_ok && balance_ok ) then
484 pprPanic ("mkBranch:"++show which) (ppAboves [ppr PprDebug [left_ok, right_ok, balance_ok],
491 result = Branch key elt (unbox (1 + left_size + right_size)) fm_l fm_r
493 -- if sizeFM result <= 8 then
496 -- pprTrace ("mkBranch:"++(show which)) (ppr PprDebug result) (
500 left_ok = case fm_l of
502 Branch left_key _ _ _ _ -> let
503 biggest_left_key = fst (findMax fm_l)
505 biggest_left_key < key
506 right_ok = case fm_r of
508 Branch right_key _ _ _ _ -> let
509 smallest_right_key = fst (findMin fm_r)
511 key < smallest_right_key
512 balance_ok = True -- sigh
515 = -- Both subtrees have one or no elements...
516 (left_size + right_size <= 1)
517 -- NO || left_size == 0 -- ???
518 -- NO || right_size == 0 -- ???
519 -- ... or the number of elements in a subtree does not exceed
520 -- sIZE_RATIO times the number of elements in the other subtree
521 || (left_size * sIZE_RATIO >= right_size &&
522 right_size * sIZE_RATIO >= left_size)
525 left_size = sizeFM fm_l
526 right_size = sizeFM fm_r
528 #if __GLASGOW_HASKELL__
530 unbox (I# size) = size
537 -- ---------------------------------------------------------------------------
538 -- {\em Balanced} construction of a @FiniteMap@
540 -- @mkBalBranch@ rebalances, assuming that the subtrees aren't too far
543 mkBalBranch :: (Ord key OUTPUTABLE_key)
545 -> FiniteMap key elt -> FiniteMap key elt
548 mkBalBranch key elt fm_L fm_R
550 | size_l + size_r < 2
551 = mkBranch 1{-which-} key elt fm_L fm_R
553 | size_r > sIZE_RATIO * size_l -- Right tree too big
555 Branch _ _ _ fm_rl fm_rr
556 | sizeFM fm_rl < 2 * sizeFM fm_rr -> single_L fm_L fm_R
557 | otherwise -> double_L fm_L fm_R
558 -- Other case impossible
560 | size_l > sIZE_RATIO * size_r -- Left tree too big
562 Branch _ _ _ fm_ll fm_lr
563 | sizeFM fm_lr < 2 * sizeFM fm_ll -> single_R fm_L fm_R
564 | otherwise -> double_R fm_L fm_R
565 -- Other case impossible
567 | otherwise -- No imbalance
568 = mkBranch 2{-which-} key elt fm_L fm_R
574 single_L fm_l (Branch key_r elt_r _ fm_rl fm_rr)
575 = mkBranch 3{-which-} key_r elt_r (mkBranch 4{-which-} key elt fm_l fm_rl) fm_rr
577 double_L fm_l (Branch key_r elt_r _ (Branch key_rl elt_rl _ fm_rll fm_rlr) fm_rr)
578 = mkBranch 5{-which-} key_rl elt_rl (mkBranch 6{-which-} key elt fm_l fm_rll)
579 (mkBranch 7{-which-} key_r elt_r fm_rlr fm_rr)
581 single_R (Branch key_l elt_l _ fm_ll fm_lr) fm_r
582 = mkBranch 8{-which-} key_l elt_l fm_ll (mkBranch 9{-which-} key elt fm_lr fm_r)
584 double_R (Branch key_l elt_l _ fm_ll (Branch key_lr elt_lr _ fm_lrl fm_lrr)) fm_r
585 = mkBranch 10{-which-} key_lr elt_lr (mkBranch 11{-which-} key_l elt_l fm_ll fm_lrl)
586 (mkBranch 12{-which-} key elt fm_lrr fm_r)
589 mkVBalBranch :: (Ord key OUTPUTABLE_key)
591 -> FiniteMap key elt -> FiniteMap key elt
594 -- Assert: in any call to (mkVBalBranch_C comb key elt l r),
595 -- (a) all keys in l are < all keys in r
596 -- (b) all keys in l are < key
597 -- (c) all keys in r are > key
599 mkVBalBranch key elt EmptyFM fm_r = addToFM fm_r key elt
600 mkVBalBranch key elt fm_l EmptyFM = addToFM fm_l key elt
602 mkVBalBranch key elt fm_l@(Branch key_l elt_l _ fm_ll fm_lr)
603 fm_r@(Branch key_r elt_r _ fm_rl fm_rr)
604 | sIZE_RATIO * size_l < size_r
605 = mkBalBranch key_r elt_r (mkVBalBranch key elt fm_l fm_rl) fm_rr
607 | sIZE_RATIO * size_r < size_l
608 = mkBalBranch key_l elt_l fm_ll (mkVBalBranch key elt fm_lr fm_r)
611 = mkBranch 13{-which-} key elt fm_l fm_r
617 -- ---------------------------------------------------------------------------
618 -- Gluing two trees together
620 -- @glueBal@ assumes its two arguments aren't too far out of whack, just
621 -- like @mkBalBranch@. But: all keys in first arg are $<$ all keys in
624 glueBal :: (Ord key OUTPUTABLE_key)
625 => FiniteMap key elt -> FiniteMap key elt
628 glueBal EmptyFM fm2 = fm2
629 glueBal fm1 EmptyFM = fm1
631 -- The case analysis here (absent in Adams' program) is really to deal
632 -- with the case where fm2 is a singleton. Then deleting the minimum means
633 -- we pass an empty tree to mkBalBranch, which breaks its invariant.
634 | sizeFM fm2 > sizeFM fm1
635 = mkBalBranch mid_key2 mid_elt2 fm1 (deleteMin fm2)
638 = mkBalBranch mid_key1 mid_elt1 (deleteMax fm1) fm2
640 (mid_key1, mid_elt1) = findMax fm1
641 (mid_key2, mid_elt2) = findMin fm2
643 -- @glueVBal@ copes with arguments which can be of any size.
644 -- But: all keys in first arg are $<$ all keys in second.
646 glueVBal :: (Ord key OUTPUTABLE_key)
647 => FiniteMap key elt -> FiniteMap key elt
650 glueVBal EmptyFM fm2 = fm2
651 glueVBal fm1 EmptyFM = fm1
652 glueVBal fm_l@(Branch key_l elt_l _ fm_ll fm_lr)
653 fm_r@(Branch key_r elt_r _ fm_rl fm_rr)
654 | sIZE_RATIO * size_l < size_r
655 = mkBalBranch key_r elt_r (glueVBal fm_l fm_rl) fm_rr
657 | sIZE_RATIO * size_r < size_l
658 = mkBalBranch key_l elt_l fm_ll (glueVBal fm_lr fm_r)
660 | otherwise -- We now need the same two cases as in glueBal above.
667 -- ---------------------------------------------------------------------------
670 splitLT, splitGT :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt
672 -- splitLT fm split_key = fm restricted to keys < split_key
673 -- splitGT fm split_key = fm restricted to keys > split_key
675 splitLT EmptyFM split_key = emptyFM
676 splitLT (Branch key elt _ fm_l fm_r) split_key
677 #if __GLASGOW_HASKELL__
678 = case _tagCmp split_key key of
679 _LT -> splitLT fm_l split_key
680 _GT -> mkVBalBranch key elt fm_l (splitLT fm_r split_key)
683 | split_key < key = splitLT fm_l split_key
684 | split_key > key = mkVBalBranch key elt fm_l (splitLT fm_r split_key)
688 splitGT EmptyFM split_key = emptyFM
689 splitGT (Branch key elt _ fm_l fm_r) split_key
690 #if __GLASGOW_HASKELL__
691 = case _tagCmp split_key key of
692 _GT -> splitGT fm_r split_key
693 _LT -> mkVBalBranch key elt (splitGT fm_l split_key) fm_r
696 | split_key > key = splitGT fm_r split_key
697 | split_key < key = mkVBalBranch key elt (splitGT fm_l split_key) fm_r
701 findMin :: FiniteMap key elt -> (key,elt)
702 findMin (Branch key elt _ EmptyFM _) = (key,elt)
703 findMin (Branch key elt _ fm_l _) = findMin fm_l
705 deleteMin :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
706 deleteMin (Branch key elt _ EmptyFM fm_r) = fm_r
707 deleteMin (Branch key elt _ fm_l fm_r) = mkBalBranch key elt (deleteMin fm_l) fm_r
709 findMax :: FiniteMap key elt -> (key,elt)
710 findMax (Branch key elt _ _ EmptyFM) = (key,elt)
711 findMax (Branch key elt _ _ fm_r) = findMax fm_r
713 deleteMax :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
714 deleteMax (Branch key elt _ fm_l EmptyFM) = fm_l
715 deleteMax (Branch key elt _ fm_l fm_r) = mkBalBranch key elt fm_l (deleteMax fm_r)
718 -- ---------------------------------------------------------------------------
721 #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)
723 instance (Outputable key) => Outputable (FiniteMap key elt) where
724 ppr sty fm = pprX sty fm
726 pprX sty EmptyFM = ppChar '!'
727 pprX sty (Branch key elt sz fm_l fm_r)
728 = ppBesides [ppLparen, pprX sty fm_l, ppSP,
729 ppr sty key, ppSP, ppInt (IF_GHC(I# sz, sz)), ppSP,
730 pprX sty fm_r, ppRparen]
733 #ifndef COMPILING_GHC
734 instance (Eq key, Eq elt) => Eq (FiniteMap key elt) where
735 fm_1 == fm_2 = (sizeFM fm_1 == sizeFM fm_2) && -- quick test
736 (fmToList fm_1 == fmToList fm_2)
738 {- NO: not clear what The Right Thing to do is:
739 instance (Ord key, Ord elt) => Ord (FiniteMap key elt) where
740 fm_1 <= fm_2 = (sizeFM fm_1 <= sizeFM fm_2) && -- quick test
741 (fmToList fm_1 <= fmToList fm_2)
745 -- ---------------------------------------------------------------------------
746 -- Efficiency pragmas for GHC
748 -- When the FiniteMap module is used in GHC, we specialise it for
749 -- \tr{Uniques}, for dastardly efficiency reasons.
751 #if defined(COMPILING_GHC) && __GLASGOW_HASKELL__ && !defined(REALLY_HASKELL_1_3)
753 {-# SPECIALIZE addListToFM
754 :: FiniteMap (FAST_STRING, FAST_STRING) elt -> [((FAST_STRING, FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) elt
755 , FiniteMap RdrName elt -> [(RdrName,elt)] -> FiniteMap RdrName elt
756 IF_NCG(COMMA FiniteMap Reg elt -> [(Reg COMMA elt)] -> FiniteMap Reg elt)
758 {-# SPECIALIZE addListToFM_C
759 :: (elt -> elt -> elt) -> FiniteMap TyCon elt -> [(TyCon,elt)] -> FiniteMap TyCon elt
760 , (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> [(FAST_STRING,elt)] -> FiniteMap FAST_STRING elt
761 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> [(Reg COMMA elt)] -> FiniteMap Reg elt)
763 {-# SPECIALIZE addToFM
764 :: FiniteMap CLabel elt -> CLabel -> elt -> FiniteMap CLabel elt
765 , FiniteMap FAST_STRING elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt
766 , FiniteMap (FAST_STRING, FAST_STRING) elt -> (FAST_STRING, FAST_STRING) -> elt -> FiniteMap (FAST_STRING, FAST_STRING) elt
767 , FiniteMap RdrName elt -> RdrName -> elt -> FiniteMap RdrName elt
768 , FiniteMap OrigName elt -> OrigName -> elt -> FiniteMap OrigName elt
769 IF_NCG(COMMA FiniteMap Reg elt -> Reg -> elt -> FiniteMap Reg elt)
771 {-# SPECIALIZE addToFM_C
772 :: (elt -> elt -> elt) -> FiniteMap (RdrName, RdrName) elt -> (RdrName, RdrName) -> elt -> FiniteMap (RdrName, RdrName) elt
773 , (elt -> elt -> elt) -> FiniteMap (OrigName, OrigName) elt -> (OrigName, OrigName) -> elt -> FiniteMap (OrigName, OrigName) elt
774 , (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt
775 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> Reg -> elt -> FiniteMap Reg elt)
777 {-# SPECIALIZE bagToFM
778 :: Bag (FAST_STRING,elt) -> FiniteMap FAST_STRING elt
780 {-# SPECIALIZE delListFromFM
781 :: FiniteMap RdrName elt -> [RdrName] -> FiniteMap RdrName elt
782 , FiniteMap OrigName elt -> [OrigName] -> FiniteMap OrigName elt
783 , FiniteMap FAST_STRING elt -> [FAST_STRING] -> FiniteMap FAST_STRING elt
784 IF_NCG(COMMA FiniteMap Reg elt -> [Reg] -> FiniteMap Reg elt)
786 {-# SPECIALIZE listToFM
787 :: [([Char],elt)] -> FiniteMap [Char] elt
788 , [(FAST_STRING,elt)] -> FiniteMap FAST_STRING elt
789 , [((FAST_STRING,FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) elt
790 , [(OrigName,elt)] -> FiniteMap OrigName elt
791 IF_NCG(COMMA [(Reg COMMA elt)] -> FiniteMap Reg elt)
793 {-# SPECIALIZE lookupFM
794 :: FiniteMap CLabel elt -> CLabel -> Maybe elt
795 , FiniteMap [Char] elt -> [Char] -> Maybe elt
796 , FiniteMap FAST_STRING elt -> FAST_STRING -> Maybe elt
797 , FiniteMap (FAST_STRING,FAST_STRING) elt -> (FAST_STRING,FAST_STRING) -> Maybe elt
798 , FiniteMap OrigName elt -> OrigName -> Maybe elt
799 , FiniteMap (OrigName,OrigName) elt -> (OrigName,OrigName) -> Maybe elt
800 , FiniteMap RdrName elt -> RdrName -> Maybe elt
801 , FiniteMap (RdrName,RdrName) elt -> (RdrName,RdrName) -> Maybe elt
802 IF_NCG(COMMA FiniteMap Reg elt -> Reg -> Maybe elt)
804 {-# SPECIALIZE lookupWithDefaultFM
805 :: FiniteMap FAST_STRING elt -> elt -> FAST_STRING -> elt
806 IF_NCG(COMMA FiniteMap Reg elt -> elt -> Reg -> elt)
808 {-# SPECIALIZE plusFM
809 :: FiniteMap RdrName elt -> FiniteMap RdrName elt -> FiniteMap RdrName elt
810 , FiniteMap OrigName elt -> FiniteMap OrigName elt -> FiniteMap OrigName elt
811 , FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt
812 IF_NCG(COMMA FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt)
814 {-# SPECIALIZE plusFM_C
815 :: (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt
816 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt)
819 #endif /* compiling for GHC */