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
+S Adams
+"Efficient sets: a balancing act"
+Journal of functional programming 3(4) Oct 1993, pp553-562
\end{display}
The code is SPECIALIZEd to various highly-desirable types (e.g., Id)
-- for details
module FiniteMap (
- FiniteMap, -- abstract type
+ FiniteMap, -- abstract type
- emptyFM, unitFM, listToFM,
+ emptyFM, unitFM, listToFM,
- addToFM,
- addToFM_C,
- addListToFM,
- addListToFM_C,
- delFromFM,
- delListFromFM,
+ addToFM,
+ addToFM_C,
+ addListToFM,
+ addListToFM_C,
+ delFromFM,
+ delListFromFM,
- plusFM,
- plusFM_C,
- minusFM,
- foldFM,
+ plusFM,
+ plusFM_C,
+ minusFM,
+ foldFM,
- intersectFM,
- intersectFM_C,
- mapFM, filterFM,
+ intersectFM,
+ intersectFM_C,
+ mapFM, filterFM,
- sizeFM, isEmptyFM, elemFM, lookupFM, lookupWithDefaultFM,
+ sizeFM, isEmptyFM, elemFM, lookupFM, lookupWithDefaultFM,
- fmToList, keysFM, eltsFM
-
- , bagToFM
+ fmToList, keysFM, eltsFM,
+ bagToFM
) where
#include "HsVersions.h"
#endif
import Maybes
-import Bag ( Bag, foldrBag )
+import Bag ( Bag, foldrBag )
import Util
import Outputable
%************************************************************************
-%* *
+%* *
\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]
+-- BUILDING
+emptyFM :: FiniteMap key elt
+unitFM :: key -> elt -> FiniteMap key elt
+-- In the case of duplicates, the last is taken:
+listToFM :: (Ord key OUTPUTABLE_key) => [(key,elt)] -> FiniteMap key elt
+-- In the case of duplicates, who knows which is taken:
+bagToFM :: (Ord key OUTPUTABLE_key) => Bag (key,elt) -> FiniteMap key elt
+
+-- 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 a1 a2) deletes from a1 any bindings which are bound in a2
+minusFM :: (Ord key OUTPUTABLE_key)
+ => FiniteMap key elt -> FiniteMap key elt -> FiniteMap key elt
+
+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 supplies a "default" elt
+-- to return for an unmapped key
+lookupWithDefaultFM :: (Ord key OUTPUTABLE_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{The @FiniteMap@ data type, and building of same}
-%* *
+%* *
%************************************************************************
Invariants about @FiniteMap@:
\end{code}
%************************************************************************
-%* *
+%* *
\subsection{Adding to and deleting from @FiniteMaps@}
-%* *
+%* *
%************************************************************************
\begin{code}
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
+ 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
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
+ 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 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)
+ (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
+ Nothing -> elt2
+ Just elt1 -> combiner elt1 elt2
-- It's worth doing plusFM specially, because we don't need
-- to do the lookup in fm1.
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
+ -- 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.
+ 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 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)
+ | 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)
+ | 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.
+ 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}
filterFM p EmptyFM = emptyFM
filterFM p (Branch key elt _ fm_l fm_r)
- | p key elt -- Keep the item
+ | p key elt -- Keep the item
= mkVBalBranch key elt (filterFM p fm_l) (filterFM p fm_r)
- | otherwise -- Drop the item
+ | 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 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
+ 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 }
\end{code}
%************************************************************************
-%* *
+%* *
\subsection{Listifying @FiniteMaps@}
-%* *
+%* *
%************************************************************************
\begin{code}
%************************************************************************
-%* *
+%* *
\subsection{The implementation of balancing}
-%* *
+%* *
%************************************************************************
%************************************************************************
-%* *
+%* *
\subsubsection{Basic construction of a @FiniteMap@}
-%* *
+%* *
%************************************************************************
@mkBranch@ simply gets the size component right. This is the ONLY
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 :: (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])
+ pprPanic ("mkBranch:"++show which)
+ (vcat [ppr [left_ok, right_ok, balance_ok],
+ ppr key,
+ ppr fm_l,
+ ppr fm_r])
else
#endif
let
- result = Branch key elt (1 + left_size + right_size) fm_l fm_r
+ result = Branch key elt (1 + left_size + right_size) fm_l fm_r
in
-- if sizeFM result <= 8 then
- result
+ result
-- else
--- pprTrace ("mkBranch:"++(show which)) (ppr result) (
--- result
--- )
+-- 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
+ 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
+ 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 + 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)
+ right_size * sIZE_RATIO >= left_size)
-}
left_size = sizeFM fm_l
\end{code}
%************************************************************************
-%* *
+%* *
\subsubsection{{\em Balanced} construction of a @FiniteMap@}
-%* *
+%* *
%************************************************************************
@mkBalBranch@ rebalances, assuming that the subtrees aren't too far
\begin{code}
mkBalBranch :: (Ord key OUTPUTABLE_key)
- => key -> elt
- -> FiniteMap key elt -> FiniteMap key elt
- -> FiniteMap key elt
+ => 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
+ | 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
+ 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
+ | 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
+ 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
+ | otherwise -- No imbalance
= mkBranch 2{-which-} key elt fm_L fm_R
where
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
+ = 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)
+ = 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)
+ = 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)
+ = 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
+ => 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
+-- (a) all keys in l are < all keys in r
+-- (b) all keys in l are < key
+-- (c) all keys in r are > key
mkVBalBranch key elt EmptyFM fm_r = addToFM fm_r key elt
mkVBalBranch key elt fm_l EmptyFM = addToFM fm_l key elt
mkVBalBranch key elt fm_l@(Branch key_l elt_l _ fm_ll fm_lr)
- fm_r@(Branch key_r elt_r _ fm_rl fm_rr)
+ 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
\end{code}
%************************************************************************
-%* *
+%* *
\subsubsection{Gluing two trees together}
-%* *
+%* *
%************************************************************************
@glueBal@ assumes its two arguments aren't too far out of whack, just
\begin{code}
glueBal :: (Ord key OUTPUTABLE_key)
- => FiniteMap key elt -> FiniteMap key elt
- -> FiniteMap key elt
+ => 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.
+ -- 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)
\begin{code}
glueVBal :: (Ord key OUTPUTABLE_key)
- => FiniteMap key elt -> FiniteMap key elt
- -> FiniteMap key elt
+ => 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)
+ 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.
+ | otherwise -- We now need the same two cases as in glueBal above.
= glueBal fm_l fm_r
where
size_l = sizeFM fm_l
\end{code}
%************************************************************************
-%* *
+%* *
\subsection{Local utilities}
-%* *
+%* *
%************************************************************************
\begin{code}
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
+ 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
+ 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)
\end{code}
%************************************************************************
-%* *
+%* *
\subsection{Output-ery}
-%* *
+%* *
%************************************************************************
\begin{code}
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])
+ 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
#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)
+ (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)
+ (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
#ifdef __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
+ :: 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
+ :: (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
+ :: 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
+ :: (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
+ :: 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
+ :: 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
+ :: [([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
+ :: 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
+ :: 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
+ :: 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
+ :: (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)
#-}
projects / ghc-hetmet.git / blobdiff