ghc-9.10.1: GHC/Data/Graph/Inductive/PatriciaTree.hs
-- |An efficient implementation of 'Data.Graph.Inductive.Graph.Graph'
-- using big-endian patricia tree (i.e. "Data.IntMap").
--
-- This module provides the following specialised functions to gain
-- more performance, using GHC's RULES pragma:
--
-- * 'Data.Graph.Inductive.Graph.insNode'
--
-- * 'Data.Graph.Inductive.Graph.insEdge'
--
-- * 'Data.Graph.Inductive.Graph.gmap'
--
-- * 'Data.Graph.Inductive.Graph.nmap'
--
-- * 'Data.Graph.Inductive.Graph.emap'
--
-- Code is from Hackage `fgl` package version 5.7.0.3
module GHC.Data.Graph.Inductive.PatriciaTree
( Gr
, UGr
)
where
import GHC.Prelude
import GHC.Data.Graph.Inductive.Graph
import Data.IntMap (IntMap)
import qualified Data.IntMap as IM
import Data.List (sort)
import Data.Maybe (fromMaybe)
import Data.Tuple (swap)
import qualified Data.IntMap.Strict as IMS
import GHC.Generics (Generic)
import Data.Bifunctor
----------------------------------------------------------------------
-- GRAPH REPRESENTATION
----------------------------------------------------------------------
newtype Gr a b = Gr (GraphRep a b)
deriving (Generic)
type GraphRep a b = IntMap (Context' a b)
type Context' a b = (IntMap [b], a, IntMap [b])
type UGr = Gr () ()
----------------------------------------------------------------------
-- CLASS INSTANCES
----------------------------------------------------------------------
instance (Eq a, Ord b) => Eq (Gr a b) where
(Gr g1) == (Gr g2) = fmap sortAdj g1 == fmap sortAdj g2
where
sortAdj (p,n,s) = (fmap sort p,n,fmap sort s)
instance (Show a, Show b) => Show (Gr a b) where
showsPrec d g = showParen (d > 10) $
showString "mkGraph "
. shows (labNodes g)
. showString " "
. shows (labEdges g)
instance (Read a, Read b) => Read (Gr a b) where
readsPrec p = readParen (p > 10) $ \ r -> do
("mkGraph", s) <- lex r
(ns,t) <- reads s
(es,u) <- reads t
return (mkGraph ns es, u)
instance Graph Gr where
empty = Gr IM.empty
isEmpty (Gr g) = IM.null g
match = matchGr
mkGraph vs es = insEdges es
. Gr
. IM.fromList
. map (second (\l -> (IM.empty,l,IM.empty)))
$ vs
labNodes (Gr g) = [ (node, label)
| (node, (_, label, _)) <- IM.toList g ]
noNodes (Gr g) = IM.size g
nodeRange (Gr g) = fromMaybe (error "nodeRange of empty graph")
$ liftA2 (,) (ix (IM.minViewWithKey g))
(ix (IM.maxViewWithKey g))
where
ix = fmap (fst . fst)
labEdges (Gr g) = do (node, (_, _, s)) <- IM.toList g
(next, labels) <- IM.toList s
label <- labels
return (node, next, label)
instance DynGraph Gr where
(p, v, l, s) & (Gr g)
= let !g1 = IM.insert v (preds, l, succs) g
!(np, preds) = fromAdjCounting p
!(ns, succs) = fromAdjCounting s
!g2 = addSucc g1 v np preds
!g3 = addPred g2 v ns succs
in Gr g3
instance Functor (Gr a) where
fmap = fastEMap
instance Bifunctor Gr where
bimap = fastNEMap
first = fastNMap
second = fastEMap
matchGr :: Node -> Gr a b -> Decomp Gr a b
matchGr node (Gr g)
= case IM.lookup node g of
Nothing
-> (Nothing, Gr g)
Just (p, label, s)
-> let !g1 = IM.delete node g
!p' = IM.delete node p
!s' = IM.delete node s
!g2 = clearPred g1 node s'
!g3 = clearSucc g2 node p'
in (Just (toAdj p', node, label, toAdj s), Gr g3)
----------------------------------------------------------------------
-- OVERRIDING FUNCTIONS
----------------------------------------------------------------------
{-
{- RULES
"insNode/Data.Graph.Inductive.PatriciaTree" insNode = fastInsNode
-}
fastInsNode :: LNode a -> Gr a b -> Gr a b
fastInsNode (v, l) (Gr g) = g' `seq` Gr g'
where
g' = IM.insert v (IM.empty, l, IM.empty) g
-}
{-# RULES
"insEdge/GHC.Data.Graph.Inductive.PatriciaTree" insEdge = fastInsEdge
#-}
fastInsEdge :: LEdge b -> Gr a b -> Gr a b
fastInsEdge (v, w, l) (Gr g) = g2 `seq` Gr g2
where
g1 = IM.adjust addS' v g
g2 = IM.adjust addP' w g1
addS' (ps, l', ss) = (ps, l', IM.insertWith addLists w [l] ss)
addP' (ps, l', ss) = (IM.insertWith addLists v [l] ps, l', ss)
{-
{- RULES
"gmap/Data.Graph.Inductive.PatriciaTree" gmap = fastGMap
-}
fastGMap :: forall a b c d. (Context a b -> Context c d) -> Gr a b -> Gr c d
fastGMap f (Gr g) = Gr (IM.mapWithKey f' g)
where
f' :: Node -> Context' a b -> Context' c d
f' = ((fromContext . f) .) . toContext
{- RULES
"nmap/Data.Graph.Inductive.PatriciaTree" nmap = fastNMap
-}
-}
fastNMap :: forall a b c. (a -> c) -> Gr a b -> Gr c b
fastNMap f (Gr g) = Gr (IM.map f' g)
where
f' :: Context' a b -> Context' c b
f' (ps, a, ss) = (ps, f a, ss)
{-
{- RULES
"emap/GHC.Data.Graph.Inductive.PatriciaTree" emap = fastEMap
-}
-}
fastEMap :: forall a b c. (b -> c) -> Gr a b -> Gr a c
fastEMap f (Gr g) = Gr (IM.map f' g)
where
f' :: Context' a b -> Context' a c
f' (ps, a, ss) = (IM.map (map f) ps, a, IM.map (map f) ss)
{- RULES
"nemap/GHC.Data.Graph.Inductive.PatriciaTree" nemap = fastNEMap
-}
fastNEMap :: forall a b c d. (a -> c) -> (b -> d) -> Gr a b -> Gr c d
fastNEMap fn fe (Gr g) = Gr (IM.map f g)
where
f :: Context' a b -> Context' c d
f (ps, a, ss) = (IM.map (map fe) ps, fn a, IM.map (map fe) ss)
----------------------------------------------------------------------
-- UTILITIES
----------------------------------------------------------------------
toAdj :: IntMap [b] -> Adj b
toAdj = concatMap expand . IM.toList
where
expand (n,ls) = map (flip (,) n) ls
--fromAdj :: Adj b -> IntMap [b]
--fromAdj = IM.fromListWith addLists . map (second (:[]) . swap)
data FromListCounting a = FromListCounting !Int !(IntMap a)
deriving (Eq, Show, Read)
getFromListCounting :: FromListCounting a -> (Int, IntMap a)
getFromListCounting (FromListCounting i m) = (i, m)
{-# INLINE getFromListCounting #-}
fromListWithKeyCounting :: (Int -> a -> a -> a) -> [(Int, a)] -> (Int, IntMap a)
fromListWithKeyCounting f = getFromListCounting . foldl' ins (FromListCounting 0 IM.empty)
where
ins (FromListCounting i t) (k,x) = FromListCounting (i + 1) (IM.insertWithKey f k x t)
{-# INLINE fromListWithKeyCounting #-}
fromListWithCounting :: (a -> a -> a) -> [(Int, a)] -> (Int, IntMap a)
fromListWithCounting f = fromListWithKeyCounting (\_ x y -> f x y)
{-# INLINE fromListWithCounting #-}
fromAdjCounting :: Adj b -> (Int, IntMap [b])
fromAdjCounting = fromListWithCounting addLists . map (second (:[]) . swap)
-- We use differenceWith to modify a graph more than bulkThreshold times,
-- and repeated insertWith otherwise.
bulkThreshold :: Int
bulkThreshold = 5
--toContext :: Node -> Context' a b -> Context a b
--toContext v (ps, a, ss) = (toAdj ps, v, a, toAdj ss)
--fromContext :: Context a b -> Context' a b
--fromContext (ps, _, a, ss) = (fromAdj ps, a, fromAdj ss)
-- A version of @++@ where order isn't important, so @xs ++ [x]@
-- becomes @x:xs@. Used when we have to have a function of type @[a]
-- -> [a] -> [a]@ but one of the lists is just going to be a single
-- element (and it isn't possible to tell which).
addLists :: [a] -> [a] -> [a]
addLists [a] as = a : as
addLists as [a] = a : as
addLists xs ys = xs ++ ys
addSucc :: forall a b . GraphRep a b -> Node -> Int -> IM.IntMap [b] -> GraphRep a b
addSucc g0 v numAdd xs
| numAdd < bulkThreshold = foldlWithKey' go g0 xs
where
go :: GraphRep a b -> Node -> [b] -> GraphRep a b
go g p l = IMS.adjust f p g
where f (ps, l', ss) = let !ss' = IM.insertWith addLists v l ss
in (ps, l', ss')
addSucc g v _ xs = IMS.differenceWith go g xs
where
go :: Context' a b -> [b] -> Maybe (Context' a b)
go (ps, l', ss) l = let !ss' = IM.insertWith addLists v l ss
in Just (ps, l', ss')
foldlWithKey' :: (a -> IM.Key -> b -> a) -> a -> IntMap b -> a
foldlWithKey' =
IM.foldlWithKey'
addPred :: forall a b . GraphRep a b -> Node -> Int -> IM.IntMap [b] -> GraphRep a b
addPred g0 v numAdd xs
| numAdd < bulkThreshold = foldlWithKey' go g0 xs
where
go :: GraphRep a b -> Node -> [b] -> GraphRep a b
go g p l = IMS.adjust f p g
where f (ps, l', ss) = let !ps' = IM.insertWith addLists v l ps
in (ps', l', ss)
addPred g v _ xs = IMS.differenceWith go g xs
where
go :: Context' a b -> [b] -> Maybe (Context' a b)
go (ps, l', ss) l = let !ps' = IM.insertWith addLists v l ps
in Just (ps', l', ss)
clearSucc :: forall a b x . GraphRep a b -> Node -> IM.IntMap x -> GraphRep a b
clearSucc g v = IMS.differenceWith go g
where
go :: Context' a b -> x -> Maybe (Context' a b)
go (ps, l, ss) _ = let !ss' = IM.delete v ss
in Just (ps, l, ss')
clearPred :: forall a b x . GraphRep a b -> Node -> IM.IntMap x -> GraphRep a b
clearPred g v = IMS.differenceWith go g
where
go :: Context' a b -> x -> Maybe (Context' a b)
go (ps, l, ss) _ = let !ps' = IM.delete v ps
in Just (ps', l, ss)
{-----------------------------------------------------------------
Copyright (c) 1999-2008, Martin Erwig
2010, Ivan Lazar Miljenovic
2022, Norman Ramsey
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