cleanup

diff --git a/scc.icl b/scc.icl
index 8c879cf..0014f50 100644 (file)
--- a/scc.icl
+++ b/scc.icl
@@ -3,36 +3,35 @@ implementation module scc
 import StdEnv, StdMaybe
 import Data.Map => qualified updateAt
 
-:: St a = {nextindex :: Int, stack :: [a], map :: Map a Annot, sccs :: [[a]]}
+:: St a  = {nextindex :: Int, stack :: [a], map :: Map a Annot, sccs :: [[a]]}
 :: Annot = {index :: Int, lowlink :: Int, onstack :: Bool}
 
 scc :: [(a, [a])] -> [[a]] | Eq, Ord a
-scc nodes = reverse (foldr strongconnect {nextindex=0,stack=[],map=newMap,sccs=[]} nodes).sccs
+scc nodes = reverse (foldr (strongconnect nodes) {nextindex=zero,stack=[],map=newMap,sccs=[]} nodes).sccs
 where
-//     strongconnect :: (a, [a]) (St a) -> St a | Eq, Ord a
-       strongconnect (v, suc) s
+       strongconnect :: [(a, [a])] (a, [a]) (St a) -> St a | Eq, Ord a
+       strongconnect nodes (v, suc) s
                | isJust (get v s.map) = s
-               # s = foldr processSucc
+               # s = foldr (processSucc nodes v)
                        { s & map   = put v {index=s.nextindex, lowlink=s.nextindex, onstack=True} s.map
                        , stack     = [v:s.stack]
-                       , nextindex = s.nextindex + 1
+                       , nextindex = inc s.nextindex
                        } suc
                # (Just a) = get v s.map
-               | a.index == a.lowlink
-                       # (scc, [sl:stack]) = span ((<>) v) s.stack
-                       # scc = scc ++ [sl]
-                       = { s & sccs = [scc:s.sccs]
-                         , stack    = stack
-                         , map      = foldr (alter \(Just s)->Just {s & onstack=False}) s.map scc
-                         }
-               = s
+               | a.index <> a.lowlink = s
+               # (scc, [sl:stack]) = span ((<>) v) s.stack
+               # scc = scc ++ [sl]
+               = { s & sccs = [scc:s.sccs]
+                 , stack    = stack
+                 , map      = foldr (alter \(Just s)->Just {s & onstack=False}) s.map scc
+                 }
        where
-//             processSucc :: a (St a) -> St a | Eq, Ord a
-               processSucc w s = case get w s.map of
+               processSucc :: [(a, [a])] a a (St a) -> St a | Eq, Ord a
+               processSucc nodes v w s = case get w s.map of
                        Nothing
-                               # n = [l\\l=:(n, _)<-nodes | n == w]
+                               # n = filter ((==)w o fst) nodes
                                | n =: [] = s
-                               # s = strongconnect (hd n) s
+                               # s = strongconnect nodes (hd n) s
                                # (Just aw) = get w s.map
                                # (Just av) = get v s.map
                                = {s & map=put v {av & lowlink=min av.lowlink aw.lowlink} s.map}