modified: src/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java

new file:   src/de/dhbwstuttgart/typeinference/unify/distributeVariance.java
	modified:   src/de/dhbwstuttgart/typeinference/unify/model/PlaceholderType.java
	new file:   src/de/dhbwstuttgart/typeinference/unify/visitUnifyTypeVisitor.java

src/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java

@@ -312,7 +312,14 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 		ArrayList<Set<Set<UnifyPair>>> remainingSets = new ArrayList<>(topLevelSets);
 		Set<Set<UnifyPair>> nextSet = remainingSets.remove(0);
 		writeLog("nextSet: " + nextSet.toString());
-		List<Set<UnifyPair>> nextSetasList = oup.sortedCopy(nextSet);//new ArrayList<>(nextSet);
+		List<Set<UnifyPair>> nextSetasList =new ArrayList<>(nextSet);
+		try {
+		//List<Set<UnifyPair>> 
+		nextSetasList = oup.sortedCopy(nextSet);//new ArrayList<>(nextSet);
+		}
+		catch (java.lang.IllegalArgumentException e) {
+			System.out.print("");
+		}
 		Set<Set<UnifyPair>> result = new HashSet<>(); 
 		int variance = 0;
 		Optional<Integer> xi = nextSetasList.stream().map(x -> x.stream().filter(y -> y.getLhsType() instanceof PlaceholderType)
@@ -615,8 +622,20 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 		// Init all 8 cases
 		for(int i = 0; i < 8; i++)
 			result.add(new HashSet<>());
+		ArrayList<UnifyPair> eq2sprime = new ArrayList<>(eq2s);
+		Iterator<UnifyPair> eq2sprimeit = eq2sprime.iterator();
+		ArrayList<UnifyPair> eq2sAsList = new ArrayList<>();
+		while(eq2sprimeit.hasNext()) {// alle mit Variance != 0 nach vorne schieben
+			UnifyPair up = eq2sprimeit.next();
+			if ((up.getLhsType() instanceof PlaceholderType && ((PlaceholderType)up.getLhsType()).getVariance() != 0)
+					|| (up.getRhsType() instanceof PlaceholderType && ((PlaceholderType)up.getRhsType()).getVariance() != 0)) {
+				eq2sAsList.add(up);
+				eq2s.remove(up);
+			}
+		}
+		eq2sAsList.addAll(eq2s);
 		Boolean first = true;
-		for(UnifyPair pair : eq2s) {
+		for(UnifyPair pair : eq2sAsList) {
 			PairOperator pairOp = pair.getPairOp();
 			UnifyType lhsType = pair.getLhsType();
 			UnifyType rhsType = pair.getRhsType();

src/de/dhbwstuttgart/typeinference/unify/distributeVariance.java

@@ -0,0 +1,19 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
+
+public class distributeVariance extends visitUnifyTypeVisitor<Integer> {
+
+	@Override
+	public PlaceholderType visit(PlaceholderType phty, Integer ht) {
+		if (ht != 0) {
+			if (phty.getVariance() == 0) {
+				phty.setVariance(ht);
+			}
+			else if (phty.getVariance() != ht) {
+				phty.setVariance(0);
+			}
+		}
+		return phty;
+	}
+}

src/de/dhbwstuttgart/typeinference/unify/model/PlaceholderType.java

@@ -7,6 +7,7 @@ import java.util.HashSet;
 import java.util.Random;
 import java.util.Set;
 
+import de.dhbwstuttgart.typeinference.unify.distributeVariance;
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
 import de.dhbwstuttgart.typeinference.unify.interfaces.UnifyTypeVisitor;
 
@@ -119,8 +120,11 @@ public final class PlaceholderType extends UnifyType{
 	
 	@Override
 	UnifyType apply(Unifier unif) {
-		if(unif.hasSubstitute(this))
-			return unif.getSubstitute(this);
+		if(unif.hasSubstitute(this)) {
+			UnifyType ret = unif.getSubstitute(this);
+			ret.accept(new distributeVariance(), this.getVariance());
+			return ret;
+		}
 		return this;
 	}
 	

src/de/dhbwstuttgart/typeinference/unify/visitUnifyTypeVisitor.java

@@ -0,0 +1,47 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.HashMap;
+import java.util.stream.Collectors;
+
+import de.dhbwstuttgart.typeinference.unify.interfaces.UnifyTypeVisitor;
+import de.dhbwstuttgart.typeinference.unify.model.ExtendsType;
+import de.dhbwstuttgart.typeinference.unify.model.FunNType;
+import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
+import de.dhbwstuttgart.typeinference.unify.model.ReferenceType;
+import de.dhbwstuttgart.typeinference.unify.model.SuperType;
+import de.dhbwstuttgart.typeinference.unify.model.TypeParams;
+
+public class visitUnifyTypeVisitor<T> implements UnifyTypeVisitor<T> {
+
+	public ReferenceType visit(ReferenceType refty, T ht) {
+		return new ReferenceType(refty.getName(),
+				new TypeParams(
+						Arrays.stream(refty.getTypeParams().get())
+						.map(x -> x.accept(this, ht))
+						.collect(Collectors.toCollection(ArrayList::new))));
+	}
+	
+	public PlaceholderType visit(PlaceholderType phty, T ht) {
+		return phty;
+	}
+	
+	public FunNType visit(FunNType funnty, T ht) {
+		return FunNType.getFunNType(
+				new TypeParams(
+						Arrays.stream(funnty.getTypeParams().get())
+						.map(x -> x.accept(this, ht))
+						.collect(Collectors.toCollection(ArrayList::new)))
+				);	
+	}
+	
+	public SuperType visit(SuperType suty, T ht) {
+		return new SuperType(suty.getWildcardedType().accept(this, ht));
+	}
+	
+	public ExtendsType visit(ExtendsType extty, T ht) {
+		return new ExtendsType(extty.getWildcardedType().accept(this, ht));
+	}
+}