removed speculative edges from PrecedenceTo Insert -> unnecessary

CupPlugin/src/de/tum/in/www2/cupplugin/views/PrecedenceToInsert.java

@@ -23,7 +23,7 @@ class PrecedenceToInsert {
 	private HashMap<terminal,Set<terminal>> edges = new HashMap<>();
 	
 	// These need to be inserted whenever an edge that contains the key is to be inserted
-	private HashMap<terminal,Set<terminal>> speculativeEdges = new HashMap<>();
+	private Pair<terminal,terminal> originalEdge;
 	
 	private int tarjanIndex;
 	private HashMap<terminal,TarjanNodeInfo> tarjanNodeInfos;
@@ -77,7 +77,6 @@ class PrecedenceToInsert {
 	 */
 	public boolean isResolvedInFavorOfShift(ShiftReduceDetails srd){
 		if(!srd.shiftAndReducePrecedenceFromSameTerminal())
-			//TODO: Check if precedence set for terminal at all
 			return hasPrecedence(srd.shift,srd.reduce);
 		else
 			return precs.get(srd.shift) == Precedence.Type.Right;
@@ -90,7 +89,6 @@ class PrecedenceToInsert {
 	 */
 	public boolean isResolvedInFavorOfReduce(ShiftReduceDetails srd) {
 		if(!srd.shiftAndReducePrecedenceFromSameTerminal())
-			//TODO: Check if precedence set for terminal at all
 			return hasPrecedence(srd.reduce,srd.shift);
 		else
 			return precs.get(srd.shift) == Precedence.Type.Left;
@@ -129,9 +127,7 @@ class PrecedenceToInsert {
 		precs.put(t, Precedence.Type.NoPrec);
 		edges.put(t, new HashSet<>());
 		
-		HashSet<terminal> spec = new HashSet<>();
-		spec.add(t);
-		speculativeEdges.put(other,spec);
+		originalEdge = new Pair<>(other,t);
 	}
 	
 	/**
@@ -152,20 +148,16 @@ class PrecedenceToInsert {
 			addedHigher = true;
 		}
 		
-		if(!precs.containsKey(lower)){
-			precs.put(lower, Precedence.Type.NoPrec);
-			edges.put(lower, new HashSet<>());
+		// Lower is guaranteed to be part of the current conflict,
+		// otherwise we would not need to insert prec since
+		// 	- not affected
+		//	- resolved the way we want it to be resolved anyway		
+		if(originalEdge.getFirst().equals(higher)){
+			// We know the for original edge u->v that u is present since u == higher
 			
-			addedLower = true;
-		}
-		
-		Set<terminal> outgoingSpecEdgesHigher = new HashSet<>();
-		if(speculativeEdges.containsKey(higher)){
-			// Insert all speculative edges that are outgoing from the node with higher pred
-			// We don't need to add it it to precs, it is already there
-			edges.get(higher).addAll(speculativeEdges.get(higher));
-			outgoingSpecEdgesHigher.addAll(speculativeEdges.get(higher));
-			speculativeEdges.remove(higher);
+			// This is a guarantee for cyclic but we let the algorithm run anyway in order to give the user
+			// the feedback about the cycle
+			edges.get(higher).add(originalEdge.getSecond());
 		}
 		
 		// Insert edge
@@ -175,20 +167,12 @@ class PrecedenceToInsert {
 			//Do rollback
 			edges.get(lower).remove(higher);
 			
-			if(outgoingSpecEdgesHigher.size() != 0){
-				// Remove from real edges
-				edges.get(higher).removeAll(outgoingSpecEdgesHigher);
+			// Remove original edge if it was added.
+			edges.get(higher).remove(originalEdge.getSecond());
 				
-				//Add to spec edges again
-				speculativeEdges.put(higher, outgoingSpecEdgesHigher);
-			}
-			
 			if(addedHigher){
 				precs.remove(higher);
 			}
-			if(addedLower){
-				precs.remove(lower);
-			}
 					
 			throw new PrecedenceCyclicException("",cycle);
 		}
@@ -368,15 +352,6 @@ class PrecedenceToInsert {
 		}
 		toCheck.addAll(edges.get(over));
 		
-		// We need to consider those as well
-		if(speculativeEdges.get(over) != null){
-			toCheck.addAll(speculativeEdges.get(over));
-		}
-		
-		// TODO:Sure ?
-		if(toCheck.size() == 0){
-			return false;
-		}
 		
 		while(toCheck.size() > 0){
 			if(toCheck.contains(t)){