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 -- NOTE: Data.FiniteMap is DEPRECATED, please use "Data.Map" instead.
13 -- A finite map implementation, derived from the paper:
14 -- /Efficient sets: a balancing act/, S. Adams,
15 -- Journal of functional programming 3(4) Oct 1993, pp553-562
17 -----------------------------------------------------------------------------
19 -- ToDo: clean up, remove the COMPILING_GHC stuff.
21 -- The code is SPECIALIZEd to various highly-desirable types (e.g., Id)
22 -- near the end (only \tr{#ifdef COMPILING_GHC}).
25 #include "HsVersions.h"
26 #define IF_NOT_GHC(a) {--}
28 #define ASSERT(e) {--}
29 #define IF_NOT_GHC(a) a
31 #define _tagCmp compare
37 #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)/* NB NB NB */
38 #define OUTPUTABLE_key , Outputable key
40 #define OUTPUTABLE_key {--}
44 {-# DEPRECATED "Please use Data.Map instead." #-}
46 -- * The @FiniteMap@ type
47 FiniteMap, -- abstract type
50 emptyFM, unitFM, listToFM,
52 -- * Lookup operations
53 lookupFM, lookupWithDefaultFM,
62 -- * Deleting elements
63 IF_NOT_GHC(delFromFM COMMA)
70 -- * Extracting information
71 fmToList, keysFM, eltsFM,
77 IF_NOT_GHC(intersectFM COMMA)
78 IF_NOT_GHC(intersectFM_C COMMA)
79 IF_NOT_GHC(mapFM COMMA filterFM COMMA)
81 foldFM_GE, fmToList_GE, keysFM_GE, eltsFM_GE,
82 foldFM_LE, fmToList_LE, keysFM_LE, eltsFM_LE,
91 import Prelude -- necessary to get dependencies right
93 import Data.Maybe ( isJust )
94 #ifdef __GLASGOW_HASKELL__
107 import Bag ( foldBag )
109 # if ! OMIT_NATIVE_CODEGEN
112 # define IF_NCG(a) {--}
116 -- SIGH: but we use unboxed "sizes"...
117 #if __GLASGOW_HASKELL__
118 #define IF_GHC(a,b) a
120 #define IF_GHC(a,b) b
124 -- ---------------------------------------------------------------------------
125 -- The signature of the module
127 -- | An empty 'FiniteMap'.
128 emptyFM :: FiniteMap key elt
130 -- | A 'FiniteMap' containing a single mapping
131 unitFM :: key -> elt -> FiniteMap key elt
133 -- | Makes a 'FiniteMap' from a list of @(key,value)@ pairs. In the
134 -- case of duplicates, the last is taken
135 listToFM :: (Ord key OUTPUTABLE_key) => [(key,elt)] -> FiniteMap key elt
138 bagToFM :: (Ord key OUTPUTABLE_key) => Bag (key,elt) -> FiniteMap key elt
139 -- In the case of duplicates, who knows which is taken
142 -- ADDING AND DELETING
144 -- | Adds an element to a 'FiniteMap'. Any previous mapping with the same
145 -- key is overwritten.
146 addToFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> elt -> FiniteMap key elt
148 -- | Adds a list of elements to a 'FiniteMap', in the order given in
149 -- the list. Overwrites previous mappings.
150 addListToFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [(key,elt)] -> FiniteMap key elt
152 -- Combines with previous binding
153 -- In the combining function, the first argument is the "old" element,
154 -- while the second is the "new" one.
156 -- | Adds an element to a 'FiniteMap'. If there is already an element
157 -- with the same key, then the specified combination function is used
158 -- to calculate the new value. The already present element is passed as
159 -- the first argument and the new element to add as second.
160 addToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
161 -> FiniteMap key elt -> key -> elt
164 -- | A list version of 'addToFM_C'. The elements are added in the
165 -- order given in the list.
166 addListToFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
167 -> FiniteMap key elt -> [(key,elt)]
170 -- | Deletes an element from a 'FiniteMap'. If there is no element with
171 -- the specified key, then the original 'FiniteMap' is returned.
172 delFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt
174 -- | List version of 'delFromFM'.
175 delListFromFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> [key] -> FiniteMap key elt
177 -- | Combine two 'FiniteMap's. Mappings in the second argument shadow
178 -- those in the first.
179 plusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
182 -- | Combine two 'FiniteMap's. The specified combination function is
183 -- used to calculate the new value when there are two elements with
185 plusFM_C :: (Ord key OUTPUTABLE_key) => (elt -> elt -> elt)
186 -> FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
188 -- | @(minusFM a1 a2)@ deletes from @a1@ any mappings which are bound in @a2@
189 minusFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt1 -> FiniteMap key elt2 -> FiniteMap key elt1
191 -- | @(intersectFM a1 a2)@ returns a new 'FiniteMap' containing
192 -- mappings from @a1@ for which @a2@ also has a mapping with the same
194 intersectFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
196 -- | Returns the intersection of two mappings, using the specified
197 -- combination function to combine values.
198 intersectFM_C :: (Ord key OUTPUTABLE_key) => (elt1 -> elt2 -> elt3)
199 -> FiniteMap key elt1 -> FiniteMap key elt2 -> FiniteMap key elt3
201 -- MAPPING, FOLDING, FILTERING
202 foldFM :: (key -> elt -> a -> a) -> a -> FiniteMap key elt -> a
203 mapFM :: (key -> elt1 -> elt2) -> FiniteMap key elt1 -> FiniteMap key elt2
204 filterFM :: (Ord key OUTPUTABLE_key) => (key -> elt -> Bool)
205 -> FiniteMap key elt -> FiniteMap key elt
208 sizeFM :: FiniteMap key elt -> Int
209 isEmptyFM :: FiniteMap key elt -> Bool
211 -- | Returns 'True' if the specified @key@ has a mapping in this
212 -- 'FiniteMap', or 'False' otherwise.
213 elemFM :: (Ord key OUTPUTABLE_key) => key -> FiniteMap key elt -> Bool
215 -- | Looks up a key in a 'FiniteMap', returning @'Just' v@ if the key
216 -- was found with value @v@, or 'Nothing' otherwise.
217 lookupFM :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> Maybe elt
219 -- | Looks up a key in a 'FiniteMap', returning @elt@ if the specified
220 -- @key@ was not found.
222 :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> elt -> key -> elt
223 -- lookupWithDefaultFM supplies a "default" elt
224 -- to return for an unmapped key
228 -- | Convert a 'FiniteMap' to a @[(key, elt)]@ sorted by 'Ord' key
230 fmToList :: FiniteMap key elt -> [(key,elt)]
232 -- | Extract the keys from a 'FiniteMap', in the order of the keys, so
234 -- > keysFM == map fst . fmToList
236 keysFM :: FiniteMap key elt -> [key]
238 -- | Extract the elements from a 'FiniteMap', in the order of the keys, so
240 -- > eltsFM == map snd . fmToList
242 eltsFM :: FiniteMap key elt -> [elt]
244 -- ---------------------------------------------------------------------------
245 -- The @FiniteMap@ data type, and building of same
247 -- Invariants about @FiniteMap@:
249 -- * all keys in a FiniteMap are distinct
251 -- * all keys in left subtree are $<$ key in Branch and
252 -- all keys in right subtree are $>$ key in Branch
254 -- * size field of a Branch gives number of Branch nodes in the tree
256 -- * size of left subtree is differs from size of right subtree by a
257 -- factor of at most \tr{sIZE_RATIO}
259 -- | A mapping from @key@s to @elt@s.
260 data FiniteMap key elt
262 | Branch key elt -- Key and elt stored here
263 IF_GHC(Int#,Int{-STRICT-}) -- Size >= 1
264 (FiniteMap key elt) -- Children
271 = Branch bottom bottom IF_GHC(0#,0) bottom bottom
273 bottom = panic "emptyFM"
276 -- #define EmptyFM (Branch _ _ IF_GHC(0#,0) _ _)
278 unitFM key elt = Branch key elt IF_GHC(1#,1) emptyFM emptyFM
280 listToFM = addListToFM emptyFM
283 bagToFM = foldBag plusFM (\ (k,v) -> unitFM k v) emptyFM
286 instance (Show k, Show e) => Show (FiniteMap k e) where
287 showsPrec p m = showsPrec p (fmToList m)
289 instance Functor (FiniteMap k) where
290 fmap f = mapFM (const f)
292 -- ---------------------------------------------------------------------------
293 -- Adding to and deleting from @FiniteMaps@
295 addToFM fm key elt = addToFM_C (\ old new -> new) fm key elt
297 addToFM_C combiner EmptyFM key elt = unitFM key elt
298 addToFM_C combiner (Branch key elt size fm_l fm_r) new_key new_elt
299 #ifdef __GLASGOW_HASKELL__
300 = case _tagCmp new_key key of
301 _LT -> mkBalBranch key elt (addToFM_C combiner fm_l new_key new_elt) fm_r
302 _GT -> mkBalBranch key elt fm_l (addToFM_C combiner fm_r new_key new_elt)
303 _EQ -> Branch new_key (combiner elt new_elt) size fm_l fm_r
305 | new_key < key = mkBalBranch key elt (addToFM_C combiner fm_l new_key new_elt) fm_r
306 | new_key > key = mkBalBranch key elt fm_l (addToFM_C combiner fm_r new_key new_elt)
307 | otherwise = Branch new_key (combiner elt new_elt) size fm_l fm_r
310 addListToFM fm key_elt_pairs = addListToFM_C (\ old new -> new) fm key_elt_pairs
312 addListToFM_C combiner fm key_elt_pairs
313 = foldl add fm key_elt_pairs -- foldl adds from the left
315 add fmap (key,elt) = addToFM_C combiner fmap key elt
318 delFromFM EmptyFM del_key = emptyFM
319 delFromFM (Branch key elt size fm_l fm_r) del_key
320 #if __GLASGOW_HASKELL__
321 = case _tagCmp del_key key of
322 _GT -> mkBalBranch key elt fm_l (delFromFM fm_r del_key)
323 _LT -> mkBalBranch key elt (delFromFM fm_l del_key) fm_r
324 _EQ -> glueBal fm_l fm_r
327 = mkBalBranch key elt fm_l (delFromFM fm_r del_key)
330 = mkBalBranch key elt (delFromFM fm_l del_key) fm_r
336 delListFromFM fm keys = foldl delFromFM fm keys
338 -- ---------------------------------------------------------------------------
339 -- Combining @FiniteMaps@
341 plusFM_C combiner EmptyFM fm2 = fm2
342 plusFM_C combiner fm1 EmptyFM = fm1
343 plusFM_C combiner fm1 (Branch split_key elt2 _ left right)
344 = mkVBalBranch split_key new_elt
345 (plusFM_C combiner lts left)
346 (plusFM_C combiner gts right)
348 lts = splitLT fm1 split_key
349 gts = splitGT fm1 split_key
350 new_elt = case lookupFM fm1 split_key of
352 Just elt1 -> combiner elt1 elt2
354 -- It's worth doing plusFM specially, because we don't need
355 -- to do the lookup in fm1.
357 plusFM EmptyFM fm2 = fm2
358 plusFM fm1 EmptyFM = fm1
359 plusFM fm1 (Branch split_key elt1 _ left right)
360 = mkVBalBranch split_key elt1 (plusFM lts left) (plusFM gts right)
362 lts = splitLT fm1 split_key
363 gts = splitGT fm1 split_key
365 minusFM EmptyFM fm2 = emptyFM
366 minusFM fm1 EmptyFM = fm1
367 minusFM fm1 (Branch split_key elt _ left right)
368 = glueVBal (minusFM lts left) (minusFM gts right)
369 -- The two can be way different, so we need glueVBal
371 lts = splitLT fm1 split_key -- NB gt and lt, so the equal ones
372 gts = splitGT fm1 split_key -- are not in either.
374 intersectFM fm1 fm2 = intersectFM_C (\ left right -> right) fm1 fm2
376 intersectFM_C combiner fm1 EmptyFM = emptyFM
377 intersectFM_C combiner EmptyFM fm2 = emptyFM
378 intersectFM_C combiner fm1 (Branch split_key elt2 _ left right)
380 | isJust maybe_elt1 -- split_elt *is* in intersection
381 = mkVBalBranch split_key (combiner elt1 elt2) (intersectFM_C combiner lts left)
382 (intersectFM_C combiner gts right)
384 | otherwise -- split_elt is *not* in intersection
385 = glueVBal (intersectFM_C combiner lts left) (intersectFM_C combiner gts right)
388 lts = splitLT fm1 split_key -- NB gt and lt, so the equal ones
389 gts = splitGT fm1 split_key -- are not in either.
391 maybe_elt1 = lookupFM fm1 split_key
392 Just elt1 = maybe_elt1
395 -- ---------------------------------------------------------------------------
396 -- Mapping, folding, and filtering with @FiniteMaps@
398 foldFM k z EmptyFM = z
399 foldFM k z (Branch key elt _ fm_l fm_r)
400 = foldFM k (k key elt (foldFM k z fm_r)) fm_l
402 mapFM f EmptyFM = emptyFM
403 mapFM f (Branch key elt size fm_l fm_r)
404 = Branch key (f key elt) size (mapFM f fm_l) (mapFM f fm_r)
406 filterFM p EmptyFM = emptyFM
407 filterFM p (Branch key elt _ fm_l fm_r)
408 | p key elt -- Keep the item
409 = mkVBalBranch key elt (filterFM p fm_l) (filterFM p fm_r)
411 | otherwise -- Drop the item
412 = glueVBal (filterFM p fm_l) (filterFM p fm_r)
415 -- ---------------------------------------------------------------------------
416 -- Interrogating @FiniteMaps@
418 --{-# INLINE sizeFM #-}
420 sizeFM (Branch _ _ size _ _) = IF_GHC(I# size, size)
422 isEmptyFM fm = sizeFM fm == 0
424 lookupFM EmptyFM key = Nothing
425 lookupFM (Branch key elt _ fm_l fm_r) key_to_find
426 #if __GLASGOW_HASKELL__
427 = case _tagCmp key_to_find key of
428 _LT -> lookupFM fm_l key_to_find
429 _GT -> lookupFM fm_r key_to_find
432 | key_to_find < key = lookupFM fm_l key_to_find
433 | key_to_find > key = lookupFM fm_r key_to_find
434 | otherwise = Just elt
438 = case (lookupFM fm key) of { Nothing -> False; Just elt -> True }
440 lookupWithDefaultFM fm deflt key
441 = case (lookupFM fm key) of { Nothing -> deflt; Just elt -> elt }
444 -- ---------------------------------------------------------------------------
445 -- Listifying @FiniteMaps@
447 fmToList fm = foldFM (\ key elt rest -> (key,elt) : rest) [] fm
448 keysFM fm = foldFM (\ key elt rest -> key : rest) [] fm
449 eltsFM fm = foldFM (\ key elt rest -> elt : rest) [] fm
452 -- ---------------------------------------------------------------------------
453 -- Bulk operations on all keys >= or <= a certain threshold
455 -- | Fold through all elements greater than or equal to the supplied key,
456 -- in increasing order.
457 foldFM_GE :: Ord key => (key -> elt -> a -> a) -> a -> key ->
458 FiniteMap key elt -> a
460 foldFM_GE k z fr EmptyFM = z
461 foldFM_GE k z fr (Branch key elt _ fm_l fm_r)
462 | key >= fr = foldFM_GE k (k key elt (foldFM_GE k z fr fm_r)) fr fm_l
463 | otherwise = foldFM_GE k z fr fm_r
465 -- | List elements greater than or equal to the supplied key, in increasing
467 fmToList_GE :: Ord key => FiniteMap key elt -> key -> [(key,elt)]
468 fmToList_GE fm fr = foldFM_GE (\ key elt rest -> (key,elt) : rest) [] fr fm
470 -- | List keys greater than or equal to the supplied key, in increasing order
471 keysFM_GE :: Ord key => FiniteMap key elt -> key -> [key]
472 keysFM_GE fm fr = foldFM_GE (\ key elt rest -> key : rest) [] fr fm
474 -- | List elements corresponding to keys greater than or equal to the supplied
475 -- key, in increasing order of key.
476 eltsFM_GE :: Ord key => FiniteMap key elt -> key -> [elt]
477 eltsFM_GE fm fr = foldFM_GE (\ key elt rest -> elt : rest) [] fr fm
479 -- | Fold through all elements less than or equal to the supplied key,
480 -- in decreasing order.
481 foldFM_LE :: Ord key => (key -> elt -> a -> a) -> a -> key ->
482 FiniteMap key elt -> a
483 foldFM_LE k z fr EmptyFM = z
484 foldFM_LE k z fr (Branch key elt _ fm_l fm_r)
485 | key <= fr = foldFM_LE k (k key elt (foldFM_LE k z fr fm_l)) fr fm_r
486 | otherwise = foldFM_LE k z fr fm_l
488 -- | List elements greater than or equal to the supplied key, in decreasing
490 fmToList_LE :: Ord key => FiniteMap key elt -> key -> [(key,elt)]
491 fmToList_LE fm fr = foldFM_LE (\ key elt rest -> (key,elt) : rest) [] fr fm
493 -- | List keys greater than or equal to the supplied key, in decreasing order
494 keysFM_LE :: Ord key => FiniteMap key elt -> key -> [key]
495 keysFM_LE fm fr = foldFM_LE (\ key elt rest -> key : rest) [] fr fm
497 -- | List elements corresponding to keys greater than or equal to the supplied
498 -- key, in decreasing order of key.
499 eltsFM_LE :: Ord key => FiniteMap key elt -> key -> [elt]
500 eltsFM_LE fm fr = foldFM_LE (\ key elt rest -> elt : rest) [] fr fm
502 -- ---------------------------------------------------------------------------
503 -- Getting minimum and maximum key out.
504 -- ---------------------------------------------------------------------------
506 -- | Extract minimum key, or Nothing if the map is empty.
507 minFM :: Ord key => FiniteMap key elt -> Maybe key
508 minFM EmptyFM = Nothing
509 minFM (Branch key _ _ fm_l _) =
512 Just key1 -> Just key1
514 -- | Extract maximum key, or Nothing if the map is empty.
515 maxFM :: Ord key => FiniteMap key elt -> Maybe key
516 maxFM EmptyFM = Nothing
517 maxFM (Branch key _ _ _ fm_r) =
520 Just key1 -> Just key1
523 -- ---------------------------------------------------------------------------
524 -- The implementation of balancing
526 -- Basic construction of a @FiniteMap@:
528 -- @mkBranch@ simply gets the size component right. This is the ONLY
529 -- (non-trivial) place the Branch object is built, so the ASSERTion
530 -- recursively checks consistency. (The trivial use of Branch is in
536 mkBranch :: (Ord key OUTPUTABLE_key) -- Used for the assertion checking only
539 -> FiniteMap key elt -> FiniteMap key elt
542 mkBranch which key elt fm_l fm_r
543 = --ASSERT( left_ok && right_ok && balance_ok )
544 #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)
545 if not ( left_ok && right_ok && balance_ok ) then
546 pprPanic ("mkBranch:"++show which) (ppAboves [ppr PprDebug [left_ok, right_ok, balance_ok],
553 result = Branch key elt (unbox (1 + left_size + right_size)) fm_l fm_r
555 -- if sizeFM result <= 8 then
558 -- pprTrace ("mkBranch:"++(show which)) (ppr PprDebug result) (
562 left_ok = case fm_l of
564 Branch left_key _ _ _ _ -> let
565 biggest_left_key = fst (findMax fm_l)
567 biggest_left_key < key
568 right_ok = case fm_r of
570 Branch right_key _ _ _ _ -> let
571 smallest_right_key = fst (findMin fm_r)
573 key < smallest_right_key
574 balance_ok = True -- sigh
577 = -- Both subtrees have one or no elements...
578 (left_size + right_size <= 1)
579 -- NO || left_size == 0 -- ???
580 -- NO || right_size == 0 -- ???
581 -- ... or the number of elements in a subtree does not exceed
582 -- sIZE_RATIO times the number of elements in the other subtree
583 || (left_size * sIZE_RATIO >= right_size &&
584 right_size * sIZE_RATIO >= left_size)
587 left_size = sizeFM fm_l
588 right_size = sizeFM fm_r
590 #if __GLASGOW_HASKELL__
592 unbox (I# size) = size
599 -- ---------------------------------------------------------------------------
600 -- {\em Balanced} construction of a @FiniteMap@
602 -- @mkBalBranch@ rebalances, assuming that the subtrees aren't too far
605 mkBalBranch :: (Ord key OUTPUTABLE_key)
607 -> FiniteMap key elt -> FiniteMap key elt
610 mkBalBranch key elt fm_L fm_R
612 | size_l + size_r < 2
613 = mkBranch 1{-which-} key elt fm_L fm_R
615 | size_r > sIZE_RATIO * size_l -- Right tree too big
617 Branch _ _ _ fm_rl fm_rr
618 | sizeFM fm_rl < 2 * sizeFM fm_rr -> single_L fm_L fm_R
619 | otherwise -> double_L fm_L fm_R
620 -- Other case impossible
622 | size_l > sIZE_RATIO * size_r -- Left tree too big
624 Branch _ _ _ fm_ll fm_lr
625 | sizeFM fm_lr < 2 * sizeFM fm_ll -> single_R fm_L fm_R
626 | otherwise -> double_R fm_L fm_R
627 -- Other case impossible
629 | otherwise -- No imbalance
630 = mkBranch 2{-which-} key elt fm_L fm_R
636 single_L fm_l (Branch key_r elt_r _ fm_rl fm_rr)
637 = mkBranch 3{-which-} key_r elt_r (mkBranch 4{-which-} key elt fm_l fm_rl) fm_rr
639 double_L fm_l (Branch key_r elt_r _ (Branch key_rl elt_rl _ fm_rll fm_rlr) fm_rr)
640 = mkBranch 5{-which-} key_rl elt_rl (mkBranch 6{-which-} key elt fm_l fm_rll)
641 (mkBranch 7{-which-} key_r elt_r fm_rlr fm_rr)
643 single_R (Branch key_l elt_l _ fm_ll fm_lr) fm_r
644 = mkBranch 8{-which-} key_l elt_l fm_ll (mkBranch 9{-which-} key elt fm_lr fm_r)
646 double_R (Branch key_l elt_l _ fm_ll (Branch key_lr elt_lr _ fm_lrl fm_lrr)) fm_r
647 = mkBranch 10{-which-} key_lr elt_lr (mkBranch 11{-which-} key_l elt_l fm_ll fm_lrl)
648 (mkBranch 12{-which-} key elt fm_lrr fm_r)
651 mkVBalBranch :: (Ord key OUTPUTABLE_key)
653 -> FiniteMap key elt -> FiniteMap key elt
656 -- Assert: in any call to (mkVBalBranch_C comb key elt l r),
657 -- (a) all keys in l are < all keys in r
658 -- (b) all keys in l are < key
659 -- (c) all keys in r are > key
661 mkVBalBranch key elt EmptyFM fm_r = addToFM fm_r key elt
662 mkVBalBranch key elt fm_l EmptyFM = addToFM fm_l key elt
664 mkVBalBranch key elt fm_l@(Branch key_l elt_l _ fm_ll fm_lr)
665 fm_r@(Branch key_r elt_r _ fm_rl fm_rr)
666 | sIZE_RATIO * size_l < size_r
667 = mkBalBranch key_r elt_r (mkVBalBranch key elt fm_l fm_rl) fm_rr
669 | sIZE_RATIO * size_r < size_l
670 = mkBalBranch key_l elt_l fm_ll (mkVBalBranch key elt fm_lr fm_r)
673 = mkBranch 13{-which-} key elt fm_l fm_r
679 -- ---------------------------------------------------------------------------
680 -- Gluing two trees together
682 -- @glueBal@ assumes its two arguments aren't too far out of whack, just
683 -- like @mkBalBranch@. But: all keys in first arg are $<$ all keys in
686 glueBal :: (Ord key OUTPUTABLE_key)
687 => FiniteMap key elt -> FiniteMap key elt
690 glueBal EmptyFM fm2 = fm2
691 glueBal fm1 EmptyFM = fm1
693 -- The case analysis here (absent in Adams' program) is really to deal
694 -- with the case where fm2 is a singleton. Then deleting the minimum means
695 -- we pass an empty tree to mkBalBranch, which breaks its invariant.
696 | sizeFM fm2 > sizeFM fm1
697 = mkBalBranch mid_key2 mid_elt2 fm1 (deleteMin fm2)
700 = mkBalBranch mid_key1 mid_elt1 (deleteMax fm1) fm2
702 (mid_key1, mid_elt1) = findMax fm1
703 (mid_key2, mid_elt2) = findMin fm2
705 -- @glueVBal@ copes with arguments which can be of any size.
706 -- But: all keys in first arg are $<$ all keys in second.
708 glueVBal :: (Ord key OUTPUTABLE_key)
709 => FiniteMap key elt -> FiniteMap key elt
712 glueVBal EmptyFM fm2 = fm2
713 glueVBal fm1 EmptyFM = fm1
714 glueVBal fm_l@(Branch key_l elt_l _ fm_ll fm_lr)
715 fm_r@(Branch key_r elt_r _ fm_rl fm_rr)
716 | sIZE_RATIO * size_l < size_r
717 = mkBalBranch key_r elt_r (glueVBal fm_l fm_rl) fm_rr
719 | sIZE_RATIO * size_r < size_l
720 = mkBalBranch key_l elt_l fm_ll (glueVBal fm_lr fm_r)
722 | otherwise -- We now need the same two cases as in glueBal above.
729 -- ---------------------------------------------------------------------------
732 splitLT, splitGT :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> key -> FiniteMap key elt
734 -- splitLT fm split_key = fm restricted to keys < split_key
735 -- splitGT fm split_key = fm restricted to keys > split_key
737 splitLT EmptyFM split_key = emptyFM
738 splitLT (Branch key elt _ fm_l fm_r) split_key
739 #if __GLASGOW_HASKELL__
740 = case _tagCmp split_key key of
741 _LT -> splitLT fm_l split_key
742 _GT -> mkVBalBranch key elt fm_l (splitLT fm_r split_key)
745 | split_key < key = splitLT fm_l split_key
746 | split_key > key = mkVBalBranch key elt fm_l (splitLT fm_r split_key)
750 splitGT EmptyFM split_key = emptyFM
751 splitGT (Branch key elt _ fm_l fm_r) split_key
752 #if __GLASGOW_HASKELL__
753 = case _tagCmp split_key key of
754 _GT -> splitGT fm_r split_key
755 _LT -> mkVBalBranch key elt (splitGT fm_l split_key) fm_r
758 | split_key > key = splitGT fm_r split_key
759 | split_key < key = mkVBalBranch key elt (splitGT fm_l split_key) fm_r
763 findMin :: FiniteMap key elt -> (key,elt)
764 findMin (Branch key elt _ EmptyFM _) = (key,elt)
765 findMin (Branch key elt _ fm_l _) = findMin fm_l
767 deleteMin :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
768 deleteMin (Branch key elt _ EmptyFM fm_r) = fm_r
769 deleteMin (Branch key elt _ fm_l fm_r) = mkBalBranch key elt (deleteMin fm_l) fm_r
771 findMax :: FiniteMap key elt -> (key,elt)
772 findMax (Branch key elt _ _ EmptyFM) = (key,elt)
773 findMax (Branch key elt _ _ fm_r) = findMax fm_r
775 deleteMax :: (Ord key OUTPUTABLE_key) => FiniteMap key elt -> FiniteMap key elt
776 deleteMax (Branch key elt _ fm_l EmptyFM) = fm_l
777 deleteMax (Branch key elt _ fm_l fm_r) = mkBalBranch key elt fm_l (deleteMax fm_r)
780 -- ---------------------------------------------------------------------------
783 #if defined(COMPILING_GHC) && defined(DEBUG_FINITEMAPS)
785 instance (Outputable key) => Outputable (FiniteMap key elt) where
786 ppr sty fm = pprX sty fm
788 pprX sty EmptyFM = ppChar '!'
789 pprX sty (Branch key elt sz fm_l fm_r)
790 = ppBesides [ppLparen, pprX sty fm_l, ppSP,
791 ppr sty key, ppSP, ppInt (IF_GHC(I# sz, sz)), ppSP,
792 pprX sty fm_r, ppRparen]
795 #ifndef COMPILING_GHC
796 instance (Eq key, Eq elt) => Eq (FiniteMap key elt) where
797 fm_1 == fm_2 = (sizeFM fm_1 == sizeFM fm_2) && -- quick test
798 (fmToList fm_1 == fmToList fm_2)
800 {- NO: not clear what The Right Thing to do is:
801 instance (Ord key, Ord elt) => Ord (FiniteMap key elt) where
802 fm_1 <= fm_2 = (sizeFM fm_1 <= sizeFM fm_2) && -- quick test
803 (fmToList fm_1 <= fmToList fm_2)
807 -- ---------------------------------------------------------------------------
808 -- Efficiency pragmas for GHC
810 -- When the FiniteMap module is used in GHC, we specialise it for
811 -- \tr{Uniques}, for dastardly efficiency reasons.
813 #if defined(COMPILING_GHC) && __GLASGOW_HASKELL__ && !defined(REALLY_HASKELL_1_3)
815 {-# SPECIALIZE addListToFM
816 :: FiniteMap (FAST_STRING, FAST_STRING) elt -> [((FAST_STRING, FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) elt
817 , FiniteMap RdrName elt -> [(RdrName,elt)] -> FiniteMap RdrName elt
818 IF_NCG(COMMA FiniteMap Reg elt -> [(Reg COMMA elt)] -> FiniteMap Reg elt)
820 {-# SPECIALIZE addListToFM_C
821 :: (elt -> elt -> elt) -> FiniteMap TyCon elt -> [(TyCon,elt)] -> FiniteMap TyCon elt
822 , (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> [(FAST_STRING,elt)] -> FiniteMap FAST_STRING elt
823 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> [(Reg COMMA elt)] -> FiniteMap Reg elt)
825 {-# SPECIALIZE addToFM
826 :: FiniteMap CLabel elt -> CLabel -> elt -> FiniteMap CLabel elt
827 , FiniteMap FAST_STRING elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt
828 , FiniteMap (FAST_STRING, FAST_STRING) elt -> (FAST_STRING, FAST_STRING) -> elt -> FiniteMap (FAST_STRING, FAST_STRING) elt
829 , FiniteMap RdrName elt -> RdrName -> elt -> FiniteMap RdrName elt
830 , FiniteMap OrigName elt -> OrigName -> elt -> FiniteMap OrigName elt
831 IF_NCG(COMMA FiniteMap Reg elt -> Reg -> elt -> FiniteMap Reg elt)
833 {-# SPECIALIZE addToFM_C
834 :: (elt -> elt -> elt) -> FiniteMap (RdrName, RdrName) elt -> (RdrName, RdrName) -> elt -> FiniteMap (RdrName, RdrName) elt
835 , (elt -> elt -> elt) -> FiniteMap (OrigName, OrigName) elt -> (OrigName, OrigName) -> elt -> FiniteMap (OrigName, OrigName) elt
836 , (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> FAST_STRING -> elt -> FiniteMap FAST_STRING elt
837 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> Reg -> elt -> FiniteMap Reg elt)
839 {-# SPECIALIZE bagToFM
840 :: Bag (FAST_STRING,elt) -> FiniteMap FAST_STRING elt
842 {-# SPECIALIZE delListFromFM
843 :: FiniteMap RdrName elt -> [RdrName] -> FiniteMap RdrName elt
844 , FiniteMap OrigName elt -> [OrigName] -> FiniteMap OrigName elt
845 , FiniteMap FAST_STRING elt -> [FAST_STRING] -> FiniteMap FAST_STRING elt
846 IF_NCG(COMMA FiniteMap Reg elt -> [Reg] -> FiniteMap Reg elt)
848 {-# SPECIALIZE listToFM
849 :: [([Char],elt)] -> FiniteMap [Char] elt
850 , [(FAST_STRING,elt)] -> FiniteMap FAST_STRING elt
851 , [((FAST_STRING,FAST_STRING),elt)] -> FiniteMap (FAST_STRING, FAST_STRING) elt
852 , [(OrigName,elt)] -> FiniteMap OrigName elt
853 IF_NCG(COMMA [(Reg COMMA elt)] -> FiniteMap Reg elt)
855 {-# SPECIALIZE lookupFM
856 :: FiniteMap CLabel elt -> CLabel -> Maybe elt
857 , FiniteMap [Char] elt -> [Char] -> Maybe elt
858 , FiniteMap FAST_STRING elt -> FAST_STRING -> Maybe elt
859 , FiniteMap (FAST_STRING,FAST_STRING) elt -> (FAST_STRING,FAST_STRING) -> Maybe elt
860 , FiniteMap OrigName elt -> OrigName -> Maybe elt
861 , FiniteMap (OrigName,OrigName) elt -> (OrigName,OrigName) -> Maybe elt
862 , FiniteMap RdrName elt -> RdrName -> Maybe elt
863 , FiniteMap (RdrName,RdrName) elt -> (RdrName,RdrName) -> Maybe elt
864 IF_NCG(COMMA FiniteMap Reg elt -> Reg -> Maybe elt)
866 {-# SPECIALIZE lookupWithDefaultFM
867 :: FiniteMap FAST_STRING elt -> elt -> FAST_STRING -> elt
868 IF_NCG(COMMA FiniteMap Reg elt -> elt -> Reg -> elt)
870 {-# SPECIALIZE plusFM
871 :: FiniteMap RdrName elt -> FiniteMap RdrName elt -> FiniteMap RdrName elt
872 , FiniteMap OrigName elt -> FiniteMap OrigName elt -> FiniteMap OrigName elt
873 , FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt
874 IF_NCG(COMMA FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt)
876 {-# SPECIALIZE plusFM_C
877 :: (elt -> elt -> elt) -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt -> FiniteMap FAST_STRING elt
878 IF_NCG(COMMA (elt -> elt -> elt) -> FiniteMap Reg elt -> FiniteMap Reg elt -> FiniteMap Reg elt)
881 #endif /* compiling for GHC */