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)
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.
146 addToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
147 -> FiniteMap key elt -> key -> elt
150 -- | A list version of 'addToFM_C'. The elements are added in the
151 -- order given in the list.
152 addListToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
153 -> FiniteMap key elt -> [(key,elt)]
156 -- | Deletes an element from a 'FiniteMap'. If there is no element with
157 -- the specified key, then the original 'FiniteMap' is returned.
158 delFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt
160 -- | List version of 'delFromFM'.
161 delListFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [key] -> FiniteMap key elt
163 -- | Combine two 'FiniteMaps'. Mappings in the second argument shadow
164 -- those in the first.
165 plusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
168 -- | Combine two 'FiniteMaps'. The specified combination function is
169 -- used to calculate the new value when there are two elements with
171 plusFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
172 -> FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
174 -- | @(minusFM a1 a2)@ deletes from @a1@ any mappings which are bound in @a2@
175 minusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
177 -- | @(intersectFM a1 a2)@ returns a new 'FiniteMap' containing
178 -- mappings from @a1@ for which @a2@ also has a mapping with the same
180 intersectFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
182 -- | Returns the interesction of two mappings, using the specified
183 -- combination function to combine values.
184 intersectFM_C :: (Ord key OUTPUTABLE_key) => (elt1 -> elt2 -> elt3)
185 -> FiniteMap key elt1 -> FiniteMap key elt2 -> FiniteMap key elt3
187 -- MAPPING, FOLDING, FILTERING
188 foldFM :: (key -> elt -> a -> a) -> a -> FiniteMap key elt -> a
189 mapFM :: (key -> elt1 -> elt2) -> FiniteMap key elt1 -> FiniteMap key elt2
190 filterFM :: (Ord key OUTPUTABLE_key) => (key -> elt -> Bool)
191 -> FiniteMap key elt -> FiniteMap key elt
194 sizeFM :: FiniteMap key elt -> Int
195 isEmptyFM :: FiniteMap key elt -> Bool
197 -- | Returns 'True' if the specified @key@ has a mapping in this
198 -- 'FiniteMap', or 'False' otherwise.
199 elemFM :: (Ord key OUTPUTABLE_key) => key -> FiniteMap key elt -> Bool
201 -- | Looks up a key in a 'FiniteMap', returning @'Just' v@ if the key
202 -- was found with value @v@, or 'Nothing' otherwise.
203 lookupFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> Maybe elt
205 -- | Looks up a key in a 'FiniteMap', returning @elt@ if the specified
206 -- @key@ was not found.
208 :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> elt -> key -> elt
209 -- lookupWithDefaultFM supplies a "default" elt
210 -- to return for an unmapped key
214 -- | Convert a 'FiniteMap' to a @[(key, elt)]@ sorted by 'Ord' key
216 fmToList :: FiniteMap key elt -> [(key,elt)]
218 -- | Extract the keys from a 'FiniteMap', in the order of the keys, so
220 -- > keysFM == map fst . fmToList
222 keysFM :: FiniteMap key elt -> [key]
224 -- | Extract the elements from a 'FiniteMap', in the order of the keys, so
226 -- > eltsFM == map snd . fmToList
228 eltsFM :: FiniteMap key elt -> [elt]
230 -- ---------------------------------------------------------------------------
231 -- The @FiniteMap@ data type, and building of same
233 -- Invariants about @FiniteMap@:
235 -- * all keys in a FiniteMap are distinct
237 -- * all keys in left subtree are $<$ key in Branch and
238 -- all keys in right subtree are $>$ key in Branch
240 -- * size field of a Branch gives number of Branch nodes in the tree
242 -- * size of left subtree is differs from size of right subtree by a
243 -- factor of at most \tr{sIZE_RATIO}
245 -- | A mapping from @key@s to @elt@s.
246 data FiniteMap key elt
248 | Branch key elt -- Key and elt stored here
249 IF_GHC(Int#,Int{-STRICT-}) -- Size >= 1
250 (FiniteMap key elt) -- Children
257 = Branch bottom bottom IF_GHC(0#,0) bottom bottom
259 bottom = panic "emptyFM"
262 -- #define EmptyFM (Branch _ _ IF_GHC(0#,0) _ _)
264 unitFM key elt = Branch key elt IF_GHC(1#,1) emptyFM emptyFM
266 listToFM = addListToFM emptyFM
269 bagToFM = foldBag plusFM (\ (k,v) -> unitFM k v) emptyFM
273 -- ---------------------------------------------------------------------------
274 -- Adding to and deleting from @FiniteMaps@
276 addToFM fm key elt = addToFM_C (\ old new -> new) fm key elt
278 addToFM_C combiner EmptyFM key elt = unitFM key elt
279 addToFM_C combiner (Branch key elt size fm_l fm_r) new_key new_elt
280 #ifdef __GLASGOW_HASKELL__
281 = case _tagCmp new_key key of
282 _LT -> mkBalBranch key elt (addToFM_C combiner fm_l new_key new_elt) fm_r
283 _GT -> mkBalBranch key elt fm_l (addToFM_C combiner fm_r new_key new_elt)
284 _EQ -> Branch new_key (combiner elt new_elt) size fm_l fm_r
286 | new_key < key = mkBalBranch key elt (addToFM_C combiner fm_l new_key new_elt) fm_r
287 | new_key > key = mkBalBranch key elt fm_l (addToFM_C combiner fm_r new_key new_elt)
288 | otherwise = Branch new_key (combiner elt new_elt) size fm_l fm_r
291 addListToFM fm key_elt_pairs = addListToFM_C (\ old new -> new) fm key_elt_pairs
293 addListToFM_C combiner fm key_elt_pairs
294 = foldl add fm key_elt_pairs -- foldl adds from the left
296 add fmap (key,elt) = addToFM_C combiner fmap key elt
299 delFromFM EmptyFM del_key = emptyFM
300 delFromFM (Branch key elt size fm_l fm_r) del_key
301 #if __GLASGOW_HASKELL__
302 = case _tagCmp del_key key of
303 _GT -> mkBalBranch key elt fm_l (delFromFM fm_r del_key)
304 _LT -> mkBalBranch key elt (delFromFM fm_l del_key) fm_r
305 _EQ -> glueBal fm_l fm_r
308 = mkBalBranch key elt fm_l (delFromFM fm_r del_key)
311 = mkBalBranch key elt (delFromFM fm_l del_key) fm_r
317 delListFromFM fm keys = foldl delFromFM fm keys
319 -- ---------------------------------------------------------------------------
320 -- Combining @FiniteMaps@
322 plusFM_C combiner EmptyFM fm2 = fm2
323 plusFM_C combiner fm1 EmptyFM = fm1
324 plusFM_C combiner fm1 (Branch split_key elt2 _ left right)
325 = mkVBalBranch split_key new_elt
326 (plusFM_C combiner lts left)
327 (plusFM_C combiner gts right)
329 lts = splitLT fm1 split_key
330 gts = splitGT fm1 split_key
331 new_elt = case lookupFM fm1 split_key of
333 Just elt1 -> combiner elt1 elt2
335 -- It's worth doing plusFM specially, because we don't need
336 -- to do the lookup in fm1.
338 plusFM EmptyFM fm2 = fm2
339 plusFM fm1 EmptyFM = fm1
340 plusFM fm1 (Branch split_key elt1 _ left right)
341 = mkVBalBranch split_key elt1 (plusFM lts left) (plusFM gts right)
343 lts = splitLT fm1 split_key
344 gts = splitGT fm1 split_key
346 minusFM EmptyFM fm2 = emptyFM
347 minusFM fm1 EmptyFM = fm1
348 minusFM fm1 (Branch split_key elt _ left right)
349 = glueVBal (minusFM lts left) (minusFM gts right)
350 -- The two can be way different, so we need glueVBal
352 lts = splitLT fm1 split_key -- NB gt and lt, so the equal ones
353 gts = splitGT fm1 split_key -- are not in either.
355 intersectFM fm1 fm2 = intersectFM_C (\ left right -> right) fm1 fm2
357 intersectFM_C combiner fm1 EmptyFM = emptyFM
358 intersectFM_C combiner EmptyFM fm2 = emptyFM
359 intersectFM_C combiner fm1 (Branch split_key elt2 _ left right)
361 | isJust maybe_elt1 -- split_elt *is* in intersection
362 = mkVBalBranch split_key (combiner elt1 elt2) (intersectFM_C combiner lts left)
363 (intersectFM_C combiner gts right)
365 | otherwise -- split_elt is *not* in intersection
366 = glueVBal (intersectFM_C combiner lts left) (intersectFM_C combiner gts right)
369 lts = splitLT fm1 split_key -- NB gt and lt, so the equal ones
370 gts = splitGT fm1 split_key -- are not in either.
372 maybe_elt1 = lookupFM fm1 split_key
373 Just elt1 = maybe_elt1
376 -- ---------------------------------------------------------------------------
377 -- Mapping, folding, and filtering with @FiniteMaps@
379 foldFM k z EmptyFM = z
380 foldFM k z (Branch key elt _ fm_l fm_r)
381 = foldFM k (k key elt (foldFM k z fm_r)) fm_l
383 mapFM f EmptyFM = emptyFM
384 mapFM f (Branch key elt size fm_l fm_r)
385 = Branch key (f key elt) size (mapFM f fm_l) (mapFM f fm_r)
387 filterFM p EmptyFM = emptyFM
388 filterFM p (Branch key elt _ fm_l fm_r)
389 | p key elt -- Keep the item
390 = mkVBalBranch key elt (filterFM p fm_l) (filterFM p fm_r)
392 | otherwise -- Drop the item
393 = glueVBal (filterFM p fm_l) (filterFM p fm_r)
396 -- ---------------------------------------------------------------------------
397 -- Interrogating @FiniteMaps@
399 --{-# INLINE sizeFM #-}
401 sizeFM (Branch _ _ size _ _) = IF_GHC(I# size, size)
403 isEmptyFM fm = sizeFM fm == 0
405 lookupFM EmptyFM key = Nothing
406 lookupFM (Branch key elt _ fm_l fm_r) key_to_find
407 #if __GLASGOW_HASKELL__
408 = case _tagCmp key_to_find key of
409 _LT -> lookupFM fm_l key_to_find
410 _GT -> lookupFM fm_r key_to_find
413 | key_to_find < key = lookupFM fm_l key_to_find
414 | key_to_find > key = lookupFM fm_r key_to_find
415 | otherwise = Just elt
419 = case (lookupFM fm key) of { Nothing -> False; Just elt -> True }
421 lookupWithDefaultFM fm deflt key
422 = case (lookupFM fm key) of { Nothing -> deflt; Just elt -> elt }
425 -- ---------------------------------------------------------------------------
426 -- Listifying @FiniteMaps@
428 fmToList fm = foldFM (\ key elt rest -> (key,elt) : rest) [] fm
429 keysFM fm = foldFM (\ key elt rest -> key : rest) [] fm
430 eltsFM fm = foldFM (\ key elt rest -> elt : rest) [] fm
433 -- ---------------------------------------------------------------------------
434 -- The implementation of balancing
436 -- Basic construction of a @FiniteMap@:
438 -- @mkBranch@ simply gets the size component right. This is the ONLY
439 -- (non-trivial) place the Branch object is built, so the ASSERTion
440 -- recursively checks consistency. (The trivial use of Branch is in
446 mkBranch :: (Ord key OUTPUTABLE_key) -- Used for the assertion checking only
449 -> FiniteMap key elt -> FiniteMap key elt
452 mkBranch which key elt fm_l fm_r
453 = --ASSERT( left_ok && right_ok && balance_ok )
454 #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)
455 if not ( left_ok && right_ok && balance_ok ) then
456 pprPanic ("mkBranch:"++show which) (ppAboves [ppr PprDebug [left_ok, right_ok, balance_ok],
463 result = Branch key elt (unbox (1 + left_size + right_size)) fm_l fm_r
465 -- if sizeFM result <= 8 then
468 -- pprTrace ("mkBranch:"++(show which)) (ppr PprDebug result) (
472 left_ok = case fm_l of
474 Branch left_key _ _ _ _ -> let
475 biggest_left_key = fst (findMax fm_l)
477 biggest_left_key < key
478 right_ok = case fm_r of
480 Branch right_key _ _ _ _ -> let
481 smallest_right_key = fst (findMin fm_r)
483 key < smallest_right_key
484 balance_ok = True -- sigh
487 = -- Both subtrees have one or no elements...
488 (left_size + right_size <= 1)
489 -- NO || left_size == 0 -- ???
490 -- NO || right_size == 0 -- ???
491 -- ... or the number of elements in a subtree does not exceed
492 -- sIZE_RATIO times the number of elements in the other subtree
493 || (left_size * sIZE_RATIO >= right_size &&
494 right_size * sIZE_RATIO >= left_size)
497 left_size = sizeFM fm_l
498 right_size = sizeFM fm_r
500 #if __GLASGOW_HASKELL__
502 unbox (I# size) = size
509 -- ---------------------------------------------------------------------------
510 -- {\em Balanced} construction of a @FiniteMap@
512 -- @mkBalBranch@ rebalances, assuming that the subtrees aren't too far
515 mkBalBranch :: (Ord key OUTPUTABLE_key)
517 -> FiniteMap key elt -> FiniteMap key elt
520 mkBalBranch key elt fm_L fm_R
522 | size_l + size_r < 2
523 = mkBranch 1{-which-} key elt fm_L fm_R
525 | size_r > sIZE_RATIO * size_l -- Right tree too big
527 Branch _ _ _ fm_rl fm_rr
528 | sizeFM fm_rl < 2 * sizeFM fm_rr -> single_L fm_L fm_R
529 | otherwise -> double_L fm_L fm_R
530 -- Other case impossible
532 | size_l > sIZE_RATIO * size_r -- Left tree too big
534 Branch _ _ _ fm_ll fm_lr
535 | sizeFM fm_lr < 2 * sizeFM fm_ll -> single_R fm_L fm_R
536 | otherwise -> double_R fm_L fm_R
537 -- Other case impossible
539 | otherwise -- No imbalance
540 = mkBranch 2{-which-} key elt fm_L fm_R
546 single_L fm_l (Branch key_r elt_r _ fm_rl fm_rr)
547 = mkBranch 3{-which-} key_r elt_r (mkBranch 4{-which-} key elt fm_l fm_rl) fm_rr
549 double_L fm_l (Branch key_r elt_r _ (Branch key_rl elt_rl _ fm_rll fm_rlr) fm_rr)
550 = mkBranch 5{-which-} key_rl elt_rl (mkBranch 6{-which-} key elt fm_l fm_rll)
551 (mkBranch 7{-which-} key_r elt_r fm_rlr fm_rr)
553 single_R (Branch key_l elt_l _ fm_ll fm_lr) fm_r
554 = mkBranch 8{-which-} key_l elt_l fm_ll (mkBranch 9{-which-} key elt fm_lr fm_r)
556 double_R (Branch key_l elt_l _ fm_ll (Branch key_lr elt_lr _ fm_lrl fm_lrr)) fm_r
557 = mkBranch 10{-which-} key_lr elt_lr (mkBranch 11{-which-} key_l elt_l fm_ll fm_lrl)
558 (mkBranch 12{-which-} key elt fm_lrr fm_r)
561 mkVBalBranch :: (Ord key OUTPUTABLE_key)
563 -> FiniteMap key elt -> FiniteMap key elt
566 -- Assert: in any call to (mkVBalBranch_C comb key elt l r),
567 -- (a) all keys in l are < all keys in r
568 -- (b) all keys in l are < key
569 -- (c) all keys in r are > key
571 mkVBalBranch key elt EmptyFM fm_r = addToFM fm_r key elt
572 mkVBalBranch key elt fm_l EmptyFM = addToFM fm_l key elt
574 mkVBalBranch key elt fm_l@(Branch key_l elt_l _ fm_ll fm_lr)
575 fm_r@(Branch key_r elt_r _ fm_rl fm_rr)
576 | sIZE_RATIO * size_l < size_r
577 = mkBalBranch key_r elt_r (mkVBalBranch key elt fm_l fm_rl) fm_rr
579 | sIZE_RATIO * size_r < size_l
580 = mkBalBranch key_l elt_l fm_ll (mkVBalBranch key elt fm_lr fm_r)
583 = mkBranch 13{-which-} key elt fm_l fm_r
589 -- ---------------------------------------------------------------------------
590 -- Gluing two trees together
592 -- @glueBal@ assumes its two arguments aren't too far out of whack, just
593 -- like @mkBalBranch@. But: all keys in first arg are $<$ all keys in
596 glueBal :: (Ord key OUTPUTABLE_key)
597 => FiniteMap key elt -> FiniteMap key elt
600 glueBal EmptyFM fm2 = fm2
601 glueBal fm1 EmptyFM = fm1
603 -- The case analysis here (absent in Adams' program) is really to deal
604 -- with the case where fm2 is a singleton. Then deleting the minimum means
605 -- we pass an empty tree to mkBalBranch, which breaks its invariant.
606 | sizeFM fm2 > sizeFM fm1
607 = mkBalBranch mid_key2 mid_elt2 fm1 (deleteMin fm2)
610 = mkBalBranch mid_key1 mid_elt1 (deleteMax fm1) fm2
612 (mid_key1, mid_elt1) = findMax fm1
613 (mid_key2, mid_elt2) = findMin fm2
615 -- @glueVBal@ copes with arguments which can be of any size.
616 -- But: all keys in first arg are $<$ all keys in second.
618 glueVBal :: (Ord key OUTPUTABLE_key)
619 => FiniteMap key elt -> FiniteMap key elt
622 glueVBal EmptyFM fm2 = fm2
623 glueVBal fm1 EmptyFM = fm1
624 glueVBal fm_l@(Branch key_l elt_l _ fm_ll fm_lr)
625 fm_r@(Branch key_r elt_r _ fm_rl fm_rr)
626 | sIZE_RATIO * size_l < size_r
627 = mkBalBranch key_r elt_r (glueVBal fm_l fm_rl) fm_rr
629 | sIZE_RATIO * size_r < size_l
630 = mkBalBranch key_l elt_l fm_ll (glueVBal fm_lr fm_r)
632 | otherwise -- We now need the same two cases as in glueBal above.
639 -- ---------------------------------------------------------------------------
642 splitLT, splitGT :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt
644 -- splitLT fm split_key = fm restricted to keys < split_key
645 -- splitGT fm split_key = fm restricted to keys > split_key
647 splitLT EmptyFM split_key = emptyFM
648 splitLT (Branch key elt _ fm_l fm_r) split_key
649 #if __GLASGOW_HASKELL__
650 = case _tagCmp split_key key of
651 _LT -> splitLT fm_l split_key
652 _GT -> mkVBalBranch key elt fm_l (splitLT fm_r split_key)
655 | split_key < key = splitLT fm_l split_key
656 | split_key > key = mkVBalBranch key elt fm_l (splitLT fm_r split_key)
660 splitGT EmptyFM split_key = emptyFM
661 splitGT (Branch key elt _ fm_l fm_r) split_key
662 #if __GLASGOW_HASKELL__
663 = case _tagCmp split_key key of
664 _GT -> splitGT fm_r split_key
665 _LT -> mkVBalBranch key elt (splitGT fm_l split_key) fm_r
668 | split_key > key = splitGT fm_r split_key
669 | split_key < key = mkVBalBranch key elt (splitGT fm_l split_key) fm_r
673 findMin :: FiniteMap key elt -> (key,elt)
674 findMin (Branch key elt _ EmptyFM _) = (key,elt)
675 findMin (Branch key elt _ fm_l _) = findMin fm_l
677 deleteMin :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
678 deleteMin (Branch key elt _ EmptyFM fm_r) = fm_r
679 deleteMin (Branch key elt _ fm_l fm_r) = mkBalBranch key elt (deleteMin fm_l) fm_r
681 findMax :: FiniteMap key elt -> (key,elt)
682 findMax (Branch key elt _ _ EmptyFM) = (key,elt)
683 findMax (Branch key elt _ _ fm_r) = findMax fm_r
685 deleteMax :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
686 deleteMax (Branch key elt _ fm_l EmptyFM) = fm_l
687 deleteMax (Branch key elt _ fm_l fm_r) = mkBalBranch key elt fm_l (deleteMax fm_r)
690 -- ---------------------------------------------------------------------------
693 #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)
695 instance (Outputable key) => Outputable (FiniteMap key elt) where
696 ppr sty fm = pprX sty fm
698 pprX sty EmptyFM = ppChar '!'
699 pprX sty (Branch key elt sz fm_l fm_r)
700 = ppBesides [ppLparen, pprX sty fm_l, ppSP,
701 ppr sty key, ppSP, ppInt (IF_GHC(I# sz, sz)), ppSP,
702 pprX sty fm_r, ppRparen]
705 #ifndef COMPILING_GHC
706 instance (Eq key, Eq elt) => Eq (FiniteMap key elt) where
707 fm_1 == fm_2 = (sizeFM fm_1 == sizeFM fm_2) && -- quick test
708 (fmToList fm_1 == fmToList fm_2)
710 {- NO: not clear what The Right Thing to do is:
711 instance (Ord key, Ord elt) => Ord (FiniteMap key elt) where
712 fm_1 <= fm_2 = (sizeFM fm_1 <= sizeFM fm_2) && -- quick test
713 (fmToList fm_1 <= fmToList fm_2)
717 -- ---------------------------------------------------------------------------
718 -- Efficiency pragmas for GHC
720 -- When the FiniteMap module is used in GHC, we specialise it for
721 -- \tr{Uniques}, for dastardly efficiency reasons.
723 #if defined(COMPILING_GHC) && __GLASGOW_HASKELL__ && !defined(REALLY_HASKELL_1_3)
725 {-# SPECIALIZE addListToFM
726 :: FiniteMap (FAST_STRING, FAST_STRING) elt -> [((FAST_STRING, FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) elt
727 , FiniteMap RdrName elt -> [(RdrName,elt)] -> FiniteMap RdrName elt
728 IF_NCG(COMMA FiniteMap Reg elt -> [(Reg COMMA elt)] -> FiniteMap Reg elt)
730 {-# SPECIALIZE addListToFM_C
731 :: (elt -> elt -> elt) -> FiniteMap TyCon elt -> [(TyCon,elt)] -> FiniteMap TyCon elt
732 , (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> [(FAST_STRING,elt)] -> FiniteMap FAST_STRING elt
733 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> [(Reg COMMA elt)] -> FiniteMap Reg elt)
735 {-# SPECIALIZE addToFM
736 :: FiniteMap CLabel elt -> CLabel -> elt -> FiniteMap CLabel elt
737 , FiniteMap FAST_STRING elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt
738 , FiniteMap (FAST_STRING, FAST_STRING) elt -> (FAST_STRING, FAST_STRING) -> elt -> FiniteMap (FAST_STRING, FAST_STRING) elt
739 , FiniteMap RdrName elt -> RdrName -> elt -> FiniteMap RdrName elt
740 , FiniteMap OrigName elt -> OrigName -> elt -> FiniteMap OrigName elt
741 IF_NCG(COMMA FiniteMap Reg elt -> Reg -> elt -> FiniteMap Reg elt)
743 {-# SPECIALIZE addToFM_C
744 :: (elt -> elt -> elt) -> FiniteMap (RdrName, RdrName) elt -> (RdrName, RdrName) -> elt -> FiniteMap (RdrName, RdrName) elt
745 , (elt -> elt -> elt) -> FiniteMap (OrigName, OrigName) elt -> (OrigName, OrigName) -> elt -> FiniteMap (OrigName, OrigName) elt
746 , (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt
747 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> Reg -> elt -> FiniteMap Reg elt)
749 {-# SPECIALIZE bagToFM
750 :: Bag (FAST_STRING,elt) -> FiniteMap FAST_STRING elt
752 {-# SPECIALIZE delListFromFM
753 :: FiniteMap RdrName elt -> [RdrName] -> FiniteMap RdrName elt
754 , FiniteMap OrigName elt -> [OrigName] -> FiniteMap OrigName elt
755 , FiniteMap FAST_STRING elt -> [FAST_STRING] -> FiniteMap FAST_STRING elt
756 IF_NCG(COMMA FiniteMap Reg elt -> [Reg] -> FiniteMap Reg elt)
758 {-# SPECIALIZE listToFM
759 :: [([Char],elt)] -> FiniteMap [Char] elt
760 , [(FAST_STRING,elt)] -> FiniteMap FAST_STRING elt
761 , [((FAST_STRING,FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) elt
762 , [(OrigName,elt)] -> FiniteMap OrigName elt
763 IF_NCG(COMMA [(Reg COMMA elt)] -> FiniteMap Reg elt)
765 {-# SPECIALIZE lookupFM
766 :: FiniteMap CLabel elt -> CLabel -> Maybe elt
767 , FiniteMap [Char] elt -> [Char] -> Maybe elt
768 , FiniteMap FAST_STRING elt -> FAST_STRING -> Maybe elt
769 , FiniteMap (FAST_STRING,FAST_STRING) elt -> (FAST_STRING,FAST_STRING) -> Maybe elt
770 , FiniteMap OrigName elt -> OrigName -> Maybe elt
771 , FiniteMap (OrigName,OrigName) elt -> (OrigName,OrigName) -> Maybe elt
772 , FiniteMap RdrName elt -> RdrName -> Maybe elt
773 , FiniteMap (RdrName,RdrName) elt -> (RdrName,RdrName) -> Maybe elt
774 IF_NCG(COMMA FiniteMap Reg elt -> Reg -> Maybe elt)
776 {-# SPECIALIZE lookupWithDefaultFM
777 :: FiniteMap FAST_STRING elt -> elt -> FAST_STRING -> elt
778 IF_NCG(COMMA FiniteMap Reg elt -> elt -> Reg -> elt)
780 {-# SPECIALIZE plusFM
781 :: FiniteMap RdrName elt -> FiniteMap RdrName elt -> FiniteMap RdrName elt
782 , FiniteMap OrigName elt -> FiniteMap OrigName elt -> FiniteMap OrigName elt
783 , FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt
784 IF_NCG(COMMA FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt)
786 {-# SPECIALIZE plusFM_C
787 :: (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt
788 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt)
791 #endif {- compiling for GHC -}