From 194b34ae4216c864d341f2dfe2055d0f3c09ed33 Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Mon, 18 Mar 2019 15:13:41 +0100
Subject: [PATCH] cleanup

---
 scc.icl | 35 +++++++++++++++++------------------
 1 file changed, 17 insertions(+), 18 deletions(-)

diff --git a/scc.icl b/scc.icl
index 8c879cf..0014f50 100644
--- 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}
-- 
2.20.1