feat: introduce task cancelling

independentTest.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+
+REPO="https://gitea.hb.dhbw-stuttgart.de/f.holzwarth/JavaCompilerCore.git"
+TDIR="./testBuild"
+
+rm -rf "$TDIR" 2>/dev/null
+mkdir $TDIR
+
+cd $TDIR
+git clone $REPO .
+git checkout feat/unify-server
+# git checkout dad468368b86bdd5a3d3b2754b17617cee0a9107 # 1:55
+# git checkout a0c11b60e8c9d7addcbe0d3a09c9ce2924e9d5c0 # 2:25
+# git checkout 4cddf73e6d6c9116d3e1705c4b27a8e7f18d80c3 # 2:27
+# git checkout 6c2d97b7703d954e4a42eef3ec374bcf313af75c # 2:13
+# git checkout f722a00fbb6e69423d48a890e4a6283471763e64 # 1:35
+# git checkout f0a4a51ce65639ce9a9470ff0fdb538fdf9c02cc # 2:19
+# git checkout 1391206dfe59263cdb22f93371cfd1dd5465d97f # 1:29
+
+date "+%Y.%m.%d %H:%M:%S"
+
+# mvn clean compile -DskipTests package
+## prefix each stderr line with " | "
+# exec 2> >(trap "" INT TERM; sed 's/^/ | /' >&2)
+# echo -e "\nMatrix test:\n |"
+# time java -jar target/JavaTXcompiler-0.1-jar-with-dependencies.jar resources/bytecode/javFiles/Matrix.jav >/dev/null;
+
+
+mvn clean compile test
+
+
+echo -e "\nCleanup... "
+cd -
+rm -rf "$TDIR" 2>/dev/null
+
+echo -e "\nFinished "
+date "+%Y.%m.%d %H:%M:%S"
+echo -e "\n "
+

pom.xml

@@ -44,6 +44,21 @@ http://maven.apache.org/maven-v4_0_0.xsd">
 			<artifactId>asm</artifactId>
 			<version>9.5</version>
 		</dependency>
+		<dependency>
+			<groupId>org.java-websocket</groupId>
+			<artifactId>Java-WebSocket</artifactId>
+			<version>1.5.2</version>
+		</dependency>
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-simple</artifactId>
+			<version>1.7.25</version>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+			<version>2.17.2</version>
+		</dependency>
 	</dependencies>
 
 	<build>

src/main/java/de/dhbwstuttgart/core/ConsoleInterface.java

@@ -5,42 +5,61 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintStream;
 import java.util.*;
-public class ConsoleInterface {
-	private static final String directory = System.getProperty("user.dir");
 
-	public static void main(String[] args) throws IOException, ClassNotFoundException {
+public class ConsoleInterface {
-		List<File> input = new ArrayList<>();
+  private static final String directory = System.getProperty("user.dir");
-		List<File> classpath = new ArrayList<>();
+
-        String outputPath = null;
+  public static void main(String[] args) throws IOException, ClassNotFoundException {
-		Iterator<String> it = Arrays.asList(args).iterator();
+    List<File> input = new ArrayList<>();
-        if(args.length == 0){
+    List<File> classpath = new ArrayList<>();
-            System.out.println("No input files given. Get help with --help");
+    String outputPath = null;
-            System.exit(1);
+    Iterator<String> it = Arrays.asList(args).iterator();
-        }else if(args.length == 1 && args[0].equals("--help")){
+    Optional<Integer> serverPort = Optional.empty();
-            System.out.println("Usage: javatx [OPTION]... [FILE]...\n" +
+    Optional<String> unifyServer = Optional.empty();
-                    "\t-cp\tSet Classpath\n" +
+
-                    "\t-d\tSet destination directory");
+    if (args.length == 0) {
-            System.exit(1);
+      System.out.println("No input files given. Get help with --help");
+      System.exit(1);
+    } else if (args.length == 1 && args[0].equals("--help")) {
+      System.out.println("Usage: javatx [OPTION]... [FILE]...\n" +
+        "\t-cp\tSet Classpath\n" +
+        "\t-d\tSet destination directory\n" +
+        "\t[--server-mode <port>]\n" +
+        "\t[--unify-server <url>]\n");
+      System.exit(1);
+    }
+    while (it.hasNext()) {
+      String arg = it.next();
+      if (arg.equals("-d")) {
+        outputPath = it.next();
+      } else if (arg.startsWith("-d")) {
+        outputPath = arg.substring(2);
+      } else if (arg.equals("-cp") || arg.equals("-classpath")) {
+        String[] cps = it.next().split(":");
+        for (String cp : cps) {
+          classpath.add(new File(cp));
         }
-		while(it.hasNext()){
+      } else if (arg.equals("--server-mode")) {
-            String arg = it.next();
+        serverPort = Optional.of(Integer.parseInt(it.next()));
-            if(arg.equals("-d")){
+      } else if (arg.equals("--unify-server")) {
-                outputPath = it.next();
+        unifyServer = Optional.of(it.next());
-            }else if(arg.startsWith("-d")) {
+      } else {
-                outputPath = arg.substring(2);
+        input.add(new File(arg));
-            }else if(arg.equals("-cp") || arg.equals("-classpath")){
+      }
-                String[] cps = it.next().split(":");
+    }
-                for(String cp : cps){
+
-                    classpath.add(new File(cp));
+    if (serverPort.isPresent()) {
-                }
+      if (unifyServer.isPresent()) throw new RuntimeException("Cannot use unifyServer when in server mode!");
-            }else{
+
-                input.add(new File(arg));
+      JavaTXServer server = new JavaTXServer(serverPort.get());
-            }
+      server.listen();
-        }
+    }
-		JavaTXCompiler compiler = new JavaTXCompiler(input, classpath, outputPath != null ? new File(outputPath) : null);
+    else {
-		//compiler.typeInference();
+      JavaTXCompiler compiler = new JavaTXCompiler(input, classpath, outputPath != null ? new File(outputPath) : null, unifyServer);
-		compiler.generateBytecode();
+      //compiler.typeInference();
-	}
+      compiler.generateBytecode();
+    }
+  }
 
 
 }

src/main/java/de/dhbwstuttgart/core/JavaTXCompiler.java

@@ -12,6 +12,7 @@ import de.dhbwstuttgart.parser.SyntaxTreeGenerator.SyntaxTreeGenerator;
 import de.dhbwstuttgart.parser.antlr.Java17Parser.SourceFileContext;
 import de.dhbwstuttgart.parser.scope.JavaClassName;
 import de.dhbwstuttgart.parser.scope.JavaClassRegistry;
+import de.dhbwstuttgart.server.SocketClient;
 import de.dhbwstuttgart.syntaxtree.ClassOrInterface;
 import de.dhbwstuttgart.syntaxtree.GenericTypeVar;
 import de.dhbwstuttgart.syntaxtree.Method;
@@ -35,10 +36,13 @@ import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
 import de.dhbwstuttgart.typeinference.constraints.Pair;
 import de.dhbwstuttgart.typeinference.result.ResultSet;
 import de.dhbwstuttgart.typeinference.typeAlgo.TYPE;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
 import de.dhbwstuttgart.typeinference.unify.RuleSet;
 import de.dhbwstuttgart.typeinference.unify.TypeUnify;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import de.dhbwstuttgart.typeinference.unify.distributeVariance;
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
 import de.dhbwstuttgart.typeinference.unify.model.PairOperator;
 import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
 import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
@@ -61,24 +65,29 @@ import org.apache.commons.io.output.NullOutputStream;
 
 public class JavaTXCompiler {
 
+	// do not use this in any code, that can be executed serverside!
+	public static PlaceholderRegistry defaultClientPlaceholderRegistry = new PlaceholderRegistry();
+
 	// public static JavaTXCompiler INSTANCE;
 	final CompilationEnvironment environment;
 	Boolean resultmodel = true;
-    public final Map<File, SourceFile> sourceFiles = new HashMap<>();
+	public final Map<File, SourceFile> sourceFiles = new HashMap<>();
 
-    Boolean log = false; //gibt an ob ein Log-File nach System.getProperty("user.dir")+""/logFiles/"" geschrieben werden soll?
+	Boolean log = false; //gibt an ob ein Log-File nach System.getProperty("user.dir")+""/logFiles/"" geschrieben werden soll?
-    public volatile UnifyTaskModel usedTasks = new UnifyTaskModel();
+	public volatile UnifyTaskModel usedTasks = new UnifyTaskModel();
-    public final DirectoryClassLoader classLoader;
+	public final DirectoryClassLoader classLoader;
 
 	public final List<File> classPath;
 	private final File outputPath;
 
+	private final Optional<String> unifyServer;
+
 	public DirectoryClassLoader getClassLoader() {
 		return classLoader;
 	}
-   
+
 	public JavaTXCompiler(File sourceFile) throws IOException, ClassNotFoundException {
-		this(Arrays.asList(sourceFile), List.of(), new File("."));
+		this(Arrays.asList(sourceFile), List.of(), new File("."), Optional.empty());
 	}
 
 	public JavaTXCompiler(File sourceFile, Boolean log) throws IOException, ClassNotFoundException {
@@ -87,10 +96,18 @@ public class JavaTXCompiler {
 	}
 
 	public JavaTXCompiler(List<File> sourceFiles) throws IOException, ClassNotFoundException {
-		this(sourceFiles, List.of(), new File("."));
+		this(sourceFiles, List.of(), new File("."), Optional.empty());
 	}
 
 	public JavaTXCompiler(List<File> sources, List<File> contextPath, File outputPath) throws IOException, ClassNotFoundException {
+		this(sources, contextPath, outputPath, Optional.empty());
+	}
+
+	public JavaTXCompiler(List<File> sources, List<File> contextPath, File outputPath, Optional<String> unifyServer) throws IOException, ClassNotFoundException {
+		// ensure new default placeholder registry for tests
+		defaultClientPlaceholderRegistry = new PlaceholderRegistry();
+
+		this.unifyServer = unifyServer;
 		var path = new ArrayList<>(contextPath);
 		if (contextPath.isEmpty()) {
 			// When no contextPaths are given, the working directory is the sources root
@@ -300,13 +317,14 @@ public class JavaTXCompiler {
 		Set<Set<UnifyPair>> results = new HashSet<>();
 		UnifyResultModel urm = null;
 		// urm.addUnifyResultListener(resultListener);
+		UnifyContext context = new UnifyContext(logFile, log, true, urm, usedTasks, defaultClientPlaceholderRegistry);
 		try {
 			logFile = logFile == null ? new FileWriter(new File("log_" + sourceFiles.keySet().iterator().next().getName())) : logFile;
-			IFiniteClosure finiteClosure = UnifyTypeFactory.generateFC(allClasses, logFile, getClassLoader(), this);
+			IFiniteClosure finiteClosure = UnifyTypeFactory.generateFC(allClasses, logFile, getClassLoader(), this, context.placeholderRegistry());
 			System.out.println(finiteClosure);
 			urm = new UnifyResultModel(cons, finiteClosure);
 			urm.addUnifyResultListener(resultListener);
-			ConstraintSet<UnifyPair> unifyCons = UnifyTypeFactory.convert(this, cons);
+			ConstraintSet<UnifyPair> unifyCons = UnifyTypeFactory.convert(this, cons, context.placeholderRegistry());
 
 			Function<UnifyPair, UnifyPair> distributeInnerVars = x -> {
 				UnifyType lhs, rhs;
@@ -320,13 +338,12 @@ public class JavaTXCompiler {
 			logFile.write(unifyCons.toString());
 			unifyCons = unifyCons.map(distributeInnerVars);
 			logFile.write(unifyCons.toString());
-			TypeUnify unify = new TypeUnify();
 			// Set<Set<UnifyPair>> results = new HashSet<>(); Nach vorne gezogen
 			logFile.write("FC:\\" + finiteClosure.toString() + "\n");
 			for (SourceFile f : this.sourceFiles.values()) {
 				logFile.write(ASTTypePrinter.print(f));
 			}
-			logFile.flush();
+			// logFile.flush();
 			Set<PlaceholderType> varianceTPHold;
 			Set<PlaceholderType> varianceTPH = new HashSet<>();
 			varianceTPH = varianceInheritanceConstraintSet(unifyCons);
@@ -342,7 +359,7 @@ public class JavaTXCompiler {
 			List<Set<Constraint<UnifyPair>>> oderConstraints = unifyCons.getOderConstraints()/*
 																								 * .stream().map(x -> { Set<Set<UnifyPair>> ret = new HashSet<>(); for (Constraint<UnifyPair> y : x) { ret.add(new HashSet<>(y)); } return ret; }).collect(Collectors. toCollection(ArrayList::new))
 																								 */;
-			unify.unifyAsync(unifyCons.getUndConstraints(), oderConstraints, finiteClosure, logFile, log, urm, usedTasks);
+			TypeUnify.unifyAsync(unifyCons.getUndConstraints(), oderConstraints, finiteClosure, context);
 		} catch (IOException e) {
 			System.err.println("kein LogFile");
 		}
@@ -365,13 +382,14 @@ public class JavaTXCompiler {
 
 		final ConstraintSet<Pair> cons = getConstraints(file);
 		Set<Set<UnifyPair>> results = new HashSet<>();
+		PlaceholderRegistry placeholderRegistry = new PlaceholderRegistry();
 		try {
 			var logFolder = new File(System.getProperty("user.dir") + "/logFiles/");
 			if (log) logFolder.mkdirs();
 			Writer logFile = log ? new FileWriter(new File(logFolder, "log_" + sourceFiles.keySet().iterator().next().getName())) : new OutputStreamWriter(new NullOutputStream());
-			IFiniteClosure finiteClosure = UnifyTypeFactory.generateFC(allClasses.stream().toList(), logFile, classLoader, this);
+			FiniteClosure finiteClosure = UnifyTypeFactory.generateFC(allClasses.stream().toList(), logFile, classLoader, this, placeholderRegistry);
 			System.out.println(finiteClosure);
-			ConstraintSet<UnifyPair> unifyCons = UnifyTypeFactory.convert(this, cons);
+			ConstraintSet<UnifyPair> unifyCons = UnifyTypeFactory.convert(this, cons, placeholderRegistry);
 			System.out.println("xxx1");
 			Function<UnifyPair, UnifyPair> distributeInnerVars = x -> {
 				UnifyType lhs, rhs;
@@ -387,12 +405,11 @@ public class JavaTXCompiler {
 			System.out.println("Unify:" + unifyCons.toString());
 			unifyCons = unifyCons.map(distributeInnerVars);
 			logFile.write("\nUnify_distributeInnerVars: " + unifyCons.toString());
-			TypeUnify unify = new TypeUnify();
 			// Set<Set<UnifyPair>> results = new HashSet<>(); Nach vorne gezogen
 			logFile.write("FC:\\" + finiteClosure.toString() + "\n");
 			logFile.write(ASTTypePrinter.print(sf));
 			System.out.println(ASTTypePrinter.print(sf));
-			logFile.flush();
+			// logFile.flush();
 			System.out.println("Unify nach Oder-Constraints-Anpassung:" + unifyCons.toString());
 			Set<PlaceholderType> varianceTPHold;
 			Set<PlaceholderType> varianceTPH = new HashSet<>();
@@ -410,16 +427,24 @@ public class JavaTXCompiler {
 			/*
 			 * Set<Set<UnifyPair>> ret = new HashSet<>(); for (Constraint<UnifyPair> y : x) { ret.add(new HashSet<>(y)); } return ret; }).collect(Collectors.toCollection(ArrayList::new))
 			 */;
-			if (resultmodel) {
+
+		  if (unifyServer.isPresent()) {
+				UnifyResultModel urm = new UnifyResultModel(cons, finiteClosure);
+				UnifyContext context = new UnifyContext(logFile, log, true, urm, usedTasks, placeholderRegistry);
+				SocketClient socketClient = new SocketClient(unifyServer.get());
+				return socketClient.execute(finiteClosure, cons, unifyCons, context);
+		  }
+			else if (resultmodel) {
 				/* UnifyResultModel Anfang */
 				UnifyResultModel urm = new UnifyResultModel(cons, finiteClosure);
 				UnifyResultListenerImpl li = new UnifyResultListenerImpl();
 				urm.addUnifyResultListener(li);
-				unify.unifyParallel(unifyCons.getUndConstraints(), oderConstraints, finiteClosure, logFile, log, urm, usedTasks);
+				UnifyContext context = new UnifyContext(logFile, log, true, urm, usedTasks, placeholderRegistry);
+				TypeUnify.unifyParallel(unifyCons.getUndConstraints(), oderConstraints, finiteClosure, context);
 				System.out.println("RESULT Final: " + li.getResults());
 				System.out.println("Constraints for Generated Generics: " + " ???");
 				logFile.write("RES_FINAL: " + li.getResults().toString() + "\n");
-				logFile.flush();
+				// logFile.flush();
 				return li.getResults();
 			}
 			/* UnifyResultModel End */
@@ -427,34 +452,35 @@ public class JavaTXCompiler {
 				// Set<Set<UnifyPair>> result = unify.unify(unifyCons.getUndConstraints(),
 				// oderConstraints, finiteClosure, logFile, log, new UnifyResultModel(cons,
 				// finiteClosure));
-				Set<Set<UnifyPair>> result = unify.unifyOderConstraints(unifyCons.getUndConstraints(), oderConstraints, finiteClosure, logFile, log, new UnifyResultModel(cons, finiteClosure), usedTasks);
+				UnifyContext context = new UnifyContext(logFile, log, false, new UnifyResultModel(cons, finiteClosure), usedTasks, placeholderRegistry);
+				Set<Set<UnifyPair>> result = TypeUnify.unifyOderConstraints(unifyCons.getUndConstraints(), oderConstraints, finiteClosure, context);
 				System.out.println("RESULT: " + result);
 				logFile.write("RES: " + result.toString() + "\n");
-				logFile.flush();
+				// logFile.flush();
 				results.addAll(result);
 
 				results = results.stream().map(x -> {
-					Optional<Set<UnifyPair>> res = new RuleSet().subst(x.stream().map(y -> {
+					Optional<Set<UnifyPair>> res = new RuleSet(placeholderRegistry).subst(x.stream().map(y -> {
 						if (y.getPairOp() == PairOperator.SMALLERDOTWC)
 							y.setPairOp(PairOperator.EQUALSDOT);
 						return y; // alle Paare a <.? b erden durch a =. b ersetzt
 					}).collect(Collectors.toCollection(HashSet::new)));
 					if (res.isPresent()) {// wenn subst ein Erg liefert wurde was veraendert
-						return new TypeUnifyTask().applyTypeUnificationRules(res.get(), finiteClosure);
+						return new TypeUnifyTask(context).applyTypeUnificationRules(res.get(), finiteClosure);
 					} else
 						return x; // wenn nichts veraendert wurde wird x zurueckgegeben
 				}).collect(Collectors.toCollection(HashSet::new));
 				System.out.println("RESULT Final: " + results);
 				System.out.println("Constraints for Generated Generics: " + " ???");
 				logFile.write("RES_FINAL: " + results.toString() + "\n");
-				logFile.flush();
+				// logFile.flush();
-				logFile.write("PLACEHOLDERS: " + PlaceholderType.EXISTING_PLACEHOLDERS);
+				logFile.write("PLACEHOLDERS: " + placeholderRegistry);
-				logFile.flush();
+				// logFile.flush();
 			}
 		} catch (IOException e) {
 			System.err.println("kein LogFile");
 		}
-		return results.stream().map((unifyPairs -> new ResultSet(UnifyTypeFactory.convert(unifyPairs, Pair.generateTPHMap(cons))))).collect(Collectors.toList());
+		return results.stream().map((unifyPairs -> new ResultSet(UnifyTypeFactory.convert(unifyPairs, Pair.generateTPHMap(cons), placeholderRegistry)))).collect(Collectors.toList());
 	}
 
 	/**
@@ -586,10 +612,6 @@ public class JavaTXCompiler {
 		}
 	}
 
-	/**
-	 * @param path - output-Directory can be null, then class file output is in the same directory as the parsed source files
-	 * @return
-	 */
 	public Map<JavaClassName, byte[]> generateBytecode(File sourceFile) throws ClassNotFoundException, IOException {
 		var sf = sourceFiles.get(sourceFile);
 		if (sf.isGenerated()) return null;

src/main/java/de/dhbwstuttgart/core/JavaTXServer.java

@@ -0,0 +1,31 @@
+package de.dhbwstuttgart.core;
+
+import de.dhbwstuttgart.server.SocketServer;
+
+public class JavaTXServer {
+
+  public static boolean isRunning = false;
+
+  final SocketServer socketServer;
+
+  public JavaTXServer(int port) {
+    this.socketServer = new SocketServer(port);
+    isRunning = true;
+  }
+
+  public void listen() {
+    socketServer.start();
+  }
+
+  public void forceStop() {
+    try {
+      socketServer.stop();
+    }
+    catch (InterruptedException exception) {
+      System.err.println("Interrupted socketServer: " + exception);
+    }
+    isRunning = false;
+  }
+
+
+}

src/main/java/de/dhbwstuttgart/exceptions/UnifyCancelException.java

@@ -0,0 +1,11 @@
+package de.dhbwstuttgart.exceptions;
+
+
+/**
+ * Eine Runtime Exception, die für den Fall genutzt wird, dass eine Unifikation abgebrochen wird.
+ * Durch das Werfen einer Exception können Abbrüche auch aus Methodenaufrufen heraus
+ * geprüft werden, da zuvor nur ein return X; stattfinden würde.
+ */
+public class UnifyCancelException extends RuntimeException {
+
+}

src/main/java/de/dhbwstuttgart/parser/SourceLoc.java

@@ -1,4 +1,25 @@
 package de.dhbwstuttgart.parser;
 
-public record SourceLoc(String file, int line) {
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+
+public record SourceLoc(String file, int line) implements ISerializableData {
+
+
+  @Override
+  public SerialMap toSerial(KeyStorage keyStorage) {
+    var serialized = new SerialMap();
+    serialized.put("file", file);
+    serialized.put("line", line);
+    return serialized;
+  }
+
+  public static SourceLoc fromSerial(SerialMap data) {
+    return new SourceLoc(
+      data.getValue("file").getOf(String.class),
+      data.getValue("line").getOf(Integer.class)
+    );
+  }
+
 }

src/main/java/de/dhbwstuttgart/parser/SyntaxTreeGenerator/FCGenerator.java

@@ -12,6 +12,7 @@ import de.dhbwstuttgart.syntaxtree.factory.ASTFactory;
 import de.dhbwstuttgart.syntaxtree.factory.UnifyTypeFactory;
 import de.dhbwstuttgart.syntaxtree.type.*;
 import de.dhbwstuttgart.typeinference.constraints.Pair;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
 import de.dhbwstuttgart.typeinference.unify.model.*;
 
 import java.util.*;
@@ -26,16 +27,21 @@ public class FCGenerator {
      *
      * @param availableClasses - Alle geparsten Klassen
      */
-    public static Set<UnifyPair> toUnifyFC(JavaTXCompiler compiler, Collection<ClassOrInterface> availableClasses, ClassLoader classLoader) throws ClassNotFoundException {
+    public static Set<UnifyPair> toUnifyFC(JavaTXCompiler compiler, Collection<ClassOrInterface> availableClasses, ClassLoader classLoader, PlaceholderRegistry placeholderRegistry) throws ClassNotFoundException {
-        return toFC(availableClasses, classLoader).stream().map(t -> UnifyTypeFactory.convert(compiler, t)).collect(Collectors.toSet());
+        return toFC(
+          availableClasses,
+          classLoader,
+          placeholderRegistry
+        ).stream().map(t -> UnifyTypeFactory.convert(compiler, t, placeholderRegistry))
+          .collect(Collectors.toSet());
     }
 
-    public static Set<Pair> toFC(Collection<ClassOrInterface> availableClasses, ClassLoader classLoader) throws ClassNotFoundException {
+    public static Set<Pair> toFC(Collection<ClassOrInterface> availableClasses, ClassLoader classLoader, PlaceholderRegistry placeholderRegistry) throws ClassNotFoundException {
         HashSet<Pair> pairs = new HashSet<>();
         //PL 2018-09-18: gtvs vor die for-Schleife gezogen, damit immer die gleichen Typeplaceholder eingesetzt werden.
         HashMap<String, RefTypeOrTPHOrWildcardOrGeneric> gtvs = new HashMap<>();
         for(ClassOrInterface cly : availableClasses){
-        	List<Pair> newPairs = getSuperTypes(cly, availableClasses, gtvs, classLoader);
+        	List<Pair> newPairs = getSuperTypes(cly, availableClasses, gtvs, classLoader, placeholderRegistry);
             pairs.addAll(newPairs);
             
             //For all Functional Interfaces FI: FunN$$<... args auf dem Functional Interface ...> <. FI is added to FC 
@@ -75,8 +81,13 @@ public class FCGenerator {
      * @param forType
      * @return
      */
-    private static List<Pair> getSuperTypes(ClassOrInterface forType, Collection<ClassOrInterface> availableClasses, ClassLoader classLoader) throws ClassNotFoundException {
+    private static List<Pair> getSuperTypes(
-        return getSuperTypes(forType, availableClasses, new HashMap<>(), classLoader);
+      ClassOrInterface forType,
+      Collection<ClassOrInterface> availableClasses,
+      ClassLoader classLoader,
+      PlaceholderRegistry placeholderRegistry
+    ) throws ClassNotFoundException {
+        return getSuperTypes(forType, availableClasses, new HashMap<>(), classLoader, placeholderRegistry);
     }
 
     /**
@@ -87,8 +98,13 @@ public class FCGenerator {
      * @return
      * @throws ClassNotFoundException
      */
-    private static List<Pair> getSuperTypes(ClassOrInterface forType, Collection<ClassOrInterface> availableClasses,
+    private static List<Pair> getSuperTypes(
-                                            HashMap<String, RefTypeOrTPHOrWildcardOrGeneric> gtvs, ClassLoader classLoader) throws ClassNotFoundException {
+      ClassOrInterface forType,
+      Collection<ClassOrInterface> availableClasses,
+      HashMap<String, RefTypeOrTPHOrWildcardOrGeneric> gtvs,
+      ClassLoader classLoader,
+      PlaceholderRegistry placeholderRegistry
+    ) throws ClassNotFoundException {
         List<RefTypeOrTPHOrWildcardOrGeneric> params = new ArrayList<>();
         //Die GTVs, die in forType hinzukommen:
         HashMap<String, RefTypeOrTPHOrWildcardOrGeneric> newGTVs = new HashMap<>();
@@ -147,7 +163,7 @@ public class FCGenerator {
             if(superClass.getClassName().equals(ASTFactory.createObjectClass().getClassName())){
                 superTypes = Arrays.asList(new Pair(ASTFactory.createObjectType(), ASTFactory.createObjectType(), PairOperator.SMALLER));
             }else{
-                superTypes = getSuperTypes(superClass, availableClasses, newGTVs, classLoader);
+                superTypes = getSuperTypes(superClass, availableClasses, newGTVs, classLoader, placeholderRegistry);
             }
 
             retList.add(ret);

src/main/java/de/dhbwstuttgart/server/SocketClient.java

@@ -0,0 +1,158 @@
+package de.dhbwstuttgart.server;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import de.dhbwstuttgart.server.packet.IPacket;
+import de.dhbwstuttgart.server.packet.IServerToClientPacket;
+import de.dhbwstuttgart.server.packet.PacketContainer;
+import de.dhbwstuttgart.server.packet.UnifyRequestPacket;
+import de.dhbwstuttgart.server.packet.UnifyResultPacket;
+import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
+import de.dhbwstuttgart.typeinference.constraints.Pair;
+import de.dhbwstuttgart.typeinference.result.ResultSet;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import java.net.URI;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CountDownLatch;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import org.java_websocket.client.WebSocketClient;
+import org.java_websocket.enums.ReadyState;
+import org.java_websocket.handshake.ServerHandshake;
+
+
+/**
+ * The Client-side of the websocket
+ */
+public class SocketClient extends WebSocketClient {
+
+  // use a latch to wait until the connection is closed by the remote host
+  private final CountDownLatch closeLatch = new CountDownLatch(1);
+  // temporarily: The received unify result
+  // TODO: replace with uuid and future system, such that responses can be mapped by a uuid to fulfill a Future
+  private UnifyResultPacket unifyResultPacket;
+
+  public SocketClient(String url) {
+    super(URI.create(url), Map.of(
+      "packetProtocolVersion", SocketServer.packetProtocolVersion
+    ));
+    // make sure, the url is in a valid format
+    final String regex = "^wss?://(\\w+(\\.\\w+)?)*:(\\d+)$";
+    final Matcher matcher = Pattern.compile(regex).matcher(url);
+    if (!matcher.find()) {
+      throw new RuntimeException("Provided string \"" + url + "\" is not a valid server URL! Use pattern ws(s?)://<host.name>:<port>");
+    }
+  }
+
+  public SocketClient(String host, int port, boolean secure) {
+    super(URI.create(String.format("%s://%s:%d/", secure ? "wss" : "ws", host, port)));
+  }
+
+  /**
+   * The main method for connecting, requesting and waiting for the server to unify.
+   * This is synchronized to prevent multiple webSockets connections at the moment, but it is not called from any
+   * thread except the main thread right now and is not necessary at all, probably. Maybe remove it later
+   */
+  synchronized public List<ResultSet> execute(
+    FiniteClosure finiteClosure,
+    ConstraintSet<Pair> constraintSet,
+    ConstraintSet<UnifyPair> unifyConstraintSet,
+    UnifyContext context
+  ) throws JsonProcessingException {
+
+    try {
+      // wait for the connection to be set up
+      this.connectBlocking();
+      // make sure the connection has been established successfully
+      if (this.getReadyState() != ReadyState.OPEN) {
+        throw new RuntimeException("WebSocket Client could not connect to remote host at " + this.uri);
+      }
+
+      // send the unify task request
+      UnifyRequestPacket packet = new UnifyRequestPacket(finiteClosure, constraintSet, unifyConstraintSet, context.placeholderRegistry());
+      String json = PacketContainer.serialize(packet);
+      this.send(json);
+
+      // block the thread, until the connection is closed by the remote host (usually after sending the results)
+      this.waitUntilClosed();
+      // wait for the connection to fully close
+      this.closeBlocking();
+    } catch (InterruptedException exception) {
+      System.err.println("Server connection interrupted: " + exception);
+      this.notifyAll();
+      throw new RuntimeException("Aborted server connection", exception);
+    }
+    catch (Exception exception) {
+      throw new RuntimeException("Exception occurred in server connection: ", exception);
+    }
+
+    // detect error cases, in which no error was thrown, but also no result was sent back from the server
+    if (this.unifyResultPacket == null) {
+      throw new RuntimeException("Did not receive server response but closed connection already");
+    }
+
+    return unifyResultPacket.getResultSet(context);
+  }
+
+  /**
+   *  Specific client-side implementations to handle incoming packets
+   */
+  protected void handleReceivedPacket(IPacket packet) {
+    if (packet instanceof IServerToClientPacket serverToClientPacket) {
+
+      try {
+        serverToClientPacket.onHandle(this.getConnection(), this);
+      }
+      catch (Exception exception) {
+        this.closeLatch.countDown();
+        this.close();
+        throw exception;
+      }
+
+      return;
+    }
+
+    System.err.println("Received package of invalid type + " + packet.getClass().getName());
+    this.close();
+  }
+
+  public void setUnifyResultSets(UnifyResultPacket unifyResultPacket) {
+    this.unifyResultPacket = unifyResultPacket;
+  }
+
+  @Override
+  public void onOpen(ServerHandshake handshakedata) {
+    System.out.println("Connected to server with status " + handshakedata.getHttpStatus());
+  }
+
+  @Override
+  public void onMessage(String message) {
+    // System.out.println("received: " + message);
+    IPacket packet = PacketContainer.deserialize(message);
+    this.handleReceivedPacket(packet);
+  }
+
+  @Override
+  public void onClose(int code, String reason, boolean remote) {
+    System.out.println(
+      "Disconnected from server " +
+        "with code " + code + " " +
+        (reason.isEmpty() ? "" : "and reason " + reason + " ") +
+        "(closed by remote: " + remote + ")"
+    );
+    this.closeLatch.countDown();
+  }
+
+  @Override
+  public void onError(Exception e) {
+    System.out.println("Error: " + e.getMessage());
+    e.printStackTrace();
+  }
+
+  public void waitUntilClosed() throws InterruptedException {
+    closeLatch.await();
+  }
+}

src/main/java/de/dhbwstuttgart/server/SocketServer.java

@@ -0,0 +1,203 @@
+package de.dhbwstuttgart.server;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import de.dhbwstuttgart.server.packet.ErrorPacket;
+import de.dhbwstuttgart.server.packet.IClientToServerPacket;
+import de.dhbwstuttgart.server.packet.IPacket;
+import de.dhbwstuttgart.server.packet.MessagePacket;
+import de.dhbwstuttgart.server.packet.PacketContainer;
+import java.net.InetSocketAddress;
+import java.util.Objects;
+import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import org.java_websocket.WebSocket;
+import org.java_websocket.handshake.ClientHandshake;
+import org.java_websocket.server.WebSocketServer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class SocketServer extends WebSocketServer {
+
+  /**
+   * Increase this every time a breaking change to the server communication is done.
+   * This will prevent errors when server version and client version do not match.
+   */
+  public static final String packetProtocolVersion = "1";
+
+  public static final Logger log = LoggerFactory.getLogger(SocketServer.class);
+
+  public SocketServer(int port) {
+    super(new InetSocketAddress(port));
+  }
+
+  @Override
+  public void onOpen(WebSocket webSocket, ClientHandshake clientHandshake) {
+    String ppv = clientHandshake.getFieldValue("packetProtocolVersion");
+    if (!ppv.equals(packetProtocolVersion)) {
+      try {
+        ErrorPacket errorPacket = ErrorPacket.create(
+          "Mismatch in packet protocol version! Client (you): " + ppv + " and Server (me): " + packetProtocolVersion,
+          true
+        );
+        webSocket.send(PacketContainer.serialize(errorPacket));
+      }
+      catch (JsonProcessingException exception) {
+        System.err.println("Failed to serialize json: " + exception);
+      }
+      webSocket.close(1);
+      return;
+    }
+
+
+    SocketData socketData = new SocketData(UUID.randomUUID().toString());
+    webSocket.setAttachment(socketData);
+    System.out.println("New connection: " + socketData.id + " (with ppv " + ppv + ")");
+
+    try {
+      sendMessage(webSocket, "Welcome to the server!");
+
+      // wait 10 seconds for the client to send a task and close the connection if nothing has been received until then
+      try (ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor()) {
+        Runnable task = () -> {
+          if (webSocket.<SocketData>getAttachment().unhandledTasks.get() == 0 || !webSocket.isOpen()) {
+            return;
+          }
+          sendMessage(webSocket, "No task received after 10 seconds. Closing connection...");
+          webSocket.close();
+        };
+        executor.schedule(task, 10, TimeUnit.SECONDS);
+        executor.shutdown();
+      }
+
+      // and finally, when your program wants to exit
+    } catch (Exception e) {
+      log.error("e: ", e);
+      webSocket.close(1, e.getMessage());
+    }
+  }
+
+  @Override
+  public void onClose(WebSocket webSocket, int code, String reason, boolean remote) {
+    SocketData socketData = webSocket.getAttachment();
+    System.out.println("Connection closed: " + socketData.id);
+    System.out.println(
+      "Disconnected client " + socketData.id + " " +
+        "with code " + code + " " +
+        (reason.isEmpty() ? "" : "and reason " + reason + " ") +
+        "(closed by client: " + remote + ")"
+    );
+
+  }
+
+  @Override
+  public void onMessage(WebSocket webSocket, String s) {
+    // System.out.println("Received: " + s.substring(0, 50));
+    IPacket reconstructedPacket = PacketContainer.deserialize(s);
+    try {
+      this.onPacketReceived(webSocket, reconstructedPacket);
+    } catch (JsonProcessingException e) {
+      this.log("Error on processing incoming package: " + e.getMessage(), webSocket);
+    }
+  }
+
+  @Override
+  public void onError(WebSocket webSocket, Exception e) {
+    log(e.getMessage(), webSocket);
+    webSocket.close();
+  }
+
+  @Override
+  public void onStart() {
+    System.out.println("Websocket server started on port " + this.getPort());
+  }
+
+  /**
+   * A shorthand method for sending informational messages to the client
+   */
+  public void sendMessage(WebSocket webSocket, String text) {
+    try {
+      MessagePacket message = new MessagePacket();
+      message.message = text;
+      webSocket.send(PacketContainer.serialize(message));
+    } catch (Exception e) {
+      System.err.println("Failed to send message: " + text);
+      log.error("e: ", e);
+    }
+  }
+
+  /**
+   * A shorthand method for sending error messages to the client
+   */
+  public void sendError(WebSocket webSocket, String text) {
+    try {
+      ErrorPacket error = new ErrorPacket();
+      error.error = text;
+      webSocket.send(PacketContainer.serialize(error));
+    } catch (Exception e) {
+      System.err.println("Failed to send error: " + text);
+      log.error("e: ", e);
+    }
+  }
+
+  /**
+   *  The server-side implementation on how to handle certain packets when received
+   */
+  private void onPacketReceived(WebSocket webSocket, IPacket packet) throws JsonProcessingException {
+    SocketData socketData = webSocket.getAttachment();
+
+    // limit the amount of tasks per connection
+    final int maxTasks = 100;
+    if (socketData.totalTasks.get() >= maxTasks) {
+      sendError(webSocket, "Exceeded the maximum amount of " + maxTasks + " tasks per session");
+      webSocket.close();
+      return;
+    }
+
+    // only allow packets, that are meant to be handled by the server
+    if (!(packet instanceof IClientToServerPacket clientToServerPacket)) {
+      sendMessage(webSocket, "The package of type " + packet.getClass().getName() + " is not handled by the server!");
+      return;
+    }
+
+    // update the socket data
+    socketData.unhandledTasks.incrementAndGet();
+    socketData.totalTasks.incrementAndGet();
+
+    // add the packet to the queue, so it can be started by the worker
+    CompletableFuture.runAsync(() -> {
+      clientToServerPacket.onHandle(webSocket, this);
+
+      // if the websocket has 0 unhandled Tasks, close the connection
+      int remainingUnhandledTasks = socketData.unhandledTasks.decrementAndGet();
+      if (remainingUnhandledTasks <= 0) {
+        sendMessage(webSocket, "All requested tasks finished! Closing connection...");
+        webSocket.close();
+      }
+    });
+  }
+
+  public void log(String msg, WebSocket webSocket) {
+    SocketData socketData = webSocket == null ? new SocketData("???") : webSocket.getAttachment();
+    System.out.println("["+socketData.id+"] " + msg);
+  }
+
+  /**
+   * The data that is associated server-side with any connected client.
+   * This makes it possible to store information that can be mapped to any existing connection.
+   */
+  public static class SocketData {
+
+    public final String id;
+    public final AtomicInteger unhandledTasks = new AtomicInteger(0);
+    public final AtomicInteger totalTasks = new AtomicInteger(0);
+
+    public SocketData(String id) {
+      this.id = id;
+    }
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/DebugPacket.java

@@ -0,0 +1,30 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import de.dhbwstuttgart.server.SocketClient;
+import de.dhbwstuttgart.server.SocketServer;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.ISerialNode;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialUUID;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialValue;
+import org.java_websocket.WebSocket;
+
+public class DebugPacket implements IClientToServerPacket, IServerToClientPacket {
+
+  public SerialUUID a1;
+  public SerialUUID a2;
+  public SerialMap b1;
+  public SerialMap b2;
+  public SerialList<? extends ISerialNode> c1;
+  public SerialList<? extends ISerialNode> c2;
+  public SerialValue<?> d1;
+  public SerialValue<?> d2;
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketClient socketServer) {}
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketServer socketServer) {}
+
+}

src/main/java/de/dhbwstuttgart/server/packet/ErrorPacket.java

@@ -0,0 +1,41 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import de.dhbwstuttgart.server.SocketClient;
+import de.dhbwstuttgart.server.SocketServer;
+import org.java_websocket.WebSocket;
+
+/**
+ * A packet to send simple error messages between the client and the server
+ */
+public class ErrorPacket implements IClientToServerPacket, IServerToClientPacket {
+
+  /**
+   * The error endpoint for messages from the server, that should be logged out outputted
+   */
+  public String error;
+  public boolean isFatal;
+
+  @JsonIgnore
+  public static ErrorPacket create(String error, boolean isFatal) {
+    ErrorPacket packet = new ErrorPacket();
+    packet.error = error;
+    packet.isFatal = isFatal;
+    return packet;
+  }
+
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketClient socketClient) {
+    System.err.println("[socket] " + "ErrorPacket: " + this.error);
+    if (this.isFatal) {
+      throw new RuntimeException("Received fatal error from server: " + this.error);
+    }
+  }
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketServer socketServer) {
+    socketServer.log("ErrorPacket: " + this.error, webSocket);
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/IClientToServerPacket.java

@@ -0,0 +1,12 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import de.dhbwstuttgart.server.SocketServer;
+import org.java_websocket.WebSocket;
+
+public interface IClientToServerPacket extends IPacket {
+
+  @JsonIgnore
+  void onHandle(WebSocket webSocket, SocketServer socketServer);
+
+}

src/main/java/de/dhbwstuttgart/server/packet/IPacket.java

@@ -0,0 +1,12 @@
+package de.dhbwstuttgart.server.packet;
+
+/**
+ * The shared interface for all packet of the client-server connection.
+ * A packet must always:
+ * - Have a default / no-parameter constructor
+ * - Have only serializable public properties (or disable them via jackson annotations)
+ *
+ */
+public interface IPacket {
+
+}

src/main/java/de/dhbwstuttgart/server/packet/IServerToClientPacket.java

@@ -0,0 +1,12 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import de.dhbwstuttgart.server.SocketClient;
+import org.java_websocket.WebSocket;
+
+public interface IServerToClientPacket extends IPacket {
+
+  @JsonIgnore
+  void onHandle(WebSocket webSocket, SocketClient socketClient);
+
+}

src/main/java/de/dhbwstuttgart/server/packet/InvalidPacket.java

@@ -0,0 +1,29 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import de.dhbwstuttgart.server.SocketClient;
+import de.dhbwstuttgart.server.SocketServer;
+import org.java_websocket.WebSocket;
+
+/**
+ * A fallback packet that is generated, if the received json could not be mapped to an existing package
+ */
+public class InvalidPacket implements IClientToServerPacket, IServerToClientPacket {
+
+  /**
+   * If available, the error that caused this package to appear
+   */
+  public String error = "<unknown error>";
+
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketClient socketClient) {
+    System.err.println("[socket] " + "InvalidPacket: " + this.error);
+  }
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketServer socketServer) {
+    socketServer.log("InvalidPacket: " + this.error, webSocket);
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/MessagePacket.java

@@ -0,0 +1,36 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import de.dhbwstuttgart.server.SocketClient;
+import de.dhbwstuttgart.server.SocketServer;
+import org.java_websocket.WebSocket;
+
+/**
+ * A packet to send simple informational messages between the client and the server
+ */
+public class MessagePacket implements IClientToServerPacket, IServerToClientPacket {
+
+  /**
+   * The informational message from the server, that should be logged out outputted
+   */
+  public String message;
+
+  @JsonIgnore
+  public static MessagePacket create(String message) {
+    MessagePacket packet = new MessagePacket();
+    packet.message = message;
+    return packet;
+  }
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketClient socketClient) {
+    System.err.println("[socket] " + this.message);
+
+  }
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketServer socketServer) {
+    socketServer.log(this.message, webSocket);
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/PacketContainer.java

@@ -0,0 +1,90 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * A wrapper for the packet to ensure correct serialization/deserialization and make it possible to detect the matching
+ * packet type for deserialization.
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public class PacketContainer {
+
+  // The jackson serializer / deserializer tool
+  private static final ObjectMapper objectMapper = new ObjectMapper();
+
+  /*
+   * The available packet types. The one type that is represented in the JSON should always be the ONLY non-null value.
+   * They have to be public (for the moment) to let jackson fill them in while deserializing
+   */
+  public ErrorPacket errorPacket = null;
+  public MessagePacket messagePacket = null;
+  public InvalidPacket invalidPacket = null;
+  public UnifyRequestPacket unifyRequestPacket = null;
+  public UnifyResultPacket unifyResultPacket = null;
+  public DebugPacket debugPacket = null;
+
+
+  /**
+   * Generate the JSON string for the given packet
+   *
+   * @param packet The packet to serialize
+   * @return The json representation of the packet
+   */
+  public static String serialize(IPacket packet) throws JsonProcessingException {
+    objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
+    PacketContainer container = new PacketContainer();
+
+    if (packet instanceof ErrorPacket)
+      container.errorPacket = (ErrorPacket) packet;
+    else if (packet instanceof MessagePacket)
+      container.messagePacket = (MessagePacket) packet;
+    else if (packet instanceof UnifyRequestPacket)
+      container.unifyRequestPacket = (UnifyRequestPacket) packet;
+    else if (packet instanceof UnifyResultPacket)
+      container.unifyResultPacket = (UnifyResultPacket) packet;
+    else if (packet instanceof DebugPacket)
+      container.debugPacket = (DebugPacket) packet;
+    // Add new packets here and in the deserialize method
+
+    return objectMapper.writeValueAsString(container);
+  }
+
+  /**
+   * Use the JSON string to generate the matching packet object
+   *
+   * @param json The serialized representation of a packet container
+   * @return The deserialized Packet object
+   */
+  public static IPacket deserialize(String json) {
+    objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
+
+    try {
+      PacketContainer container = objectMapper.readValue(json, PacketContainer.class);
+
+      if (container.errorPacket != null)
+        return container.errorPacket;
+      if (container.messagePacket != null)
+        return container.messagePacket;
+      if (container.invalidPacket != null)
+        return container.invalidPacket;
+      if (container.unifyRequestPacket != null)
+        return container.unifyRequestPacket;
+      if (container.unifyResultPacket != null)
+        return container.unifyResultPacket;
+      if (container.debugPacket != null)
+        return container.debugPacket;
+      // Add new packets here and in the serialize method
+
+      throw new RuntimeException("Cannot map received json to any known packet class");
+    } catch (Exception e) {
+      System.out.println(e);
+      InvalidPacket packet = new InvalidPacket();
+      packet.error = e.getMessage();
+      return packet;
+    }
+  }
+
+
+}

src/main/java/de/dhbwstuttgart/server/packet/UnifyRequestPacket.java

@@ -0,0 +1,145 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import de.dhbwstuttgart.server.SocketServer;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialValue;
+import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
+import de.dhbwstuttgart.typeinference.constraints.Pair;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
+import de.dhbwstuttgart.typeinference.unify.TypeUnify;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.UnifyResultListenerImpl;
+import de.dhbwstuttgart.typeinference.unify.UnifyResultModel;
+import de.dhbwstuttgart.typeinference.unify.UnifyTaskModel;
+import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyType;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.concurrent.ForkJoinPool;
+import org.java_websocket.WebSocket;
+
+/**
+ * A packet to send all required data for the unification algorithm to the server and request the unification
+ */
+public class UnifyRequestPacket implements IClientToServerPacket {
+
+  public SerialMap finiteClosure;
+  public SerialMap constraintSet;
+  public SerialMap unifyConstraintSet;
+  public SerialMap serialKeyStorage;
+  public SerialValue<?> placeholders;
+  public SerialList<SerialMap> factoryplaceholders;
+
+  @JsonIgnore
+  private KeyStorage keyStorage = new KeyStorage();
+  @JsonIgnore
+  private boolean keyStorageLoaded = false;
+
+  public UnifyRequestPacket() {}
+
+  public UnifyRequestPacket(
+    FiniteClosure finiteClosure,
+    ConstraintSet<Pair> constraintSet,
+    ConstraintSet<UnifyPair> unifyConstraintSet,
+    PlaceholderRegistry placeholderRegistry
+  ) {
+    // store contraint and finite closure
+    this.finiteClosure = finiteClosure.toSerial(keyStorage);
+    this.constraintSet = constraintSet.toSerial(keyStorage);
+    this.unifyConstraintSet = unifyConstraintSet.toSerial(keyStorage);
+    // store placeholder registry
+    var serialRegistry = placeholderRegistry.toSerial(keyStorage);
+    this.placeholders = serialRegistry.getValue("ph");
+    this.factoryplaceholders = serialRegistry.getList("factoryPh").assertListOfMaps();
+    // store referenced objects separately
+    this.serialKeyStorage = keyStorage.toSerial(keyStorage);
+  }
+
+
+  @JsonIgnore
+  public void loadKeyStorage(UnifyContext context) {
+    if (!keyStorageLoaded) {
+      keyStorageLoaded = true;
+      keyStorage = KeyStorage.fromSerial(this.serialKeyStorage, context);
+    }
+  }
+
+  @JsonIgnore
+  private FiniteClosure retrieveFiniteClosure(UnifyContext context) {
+    this.loadKeyStorage(context);
+    return FiniteClosure.fromSerial(this.finiteClosure, context, keyStorage);
+  }
+
+  @JsonIgnore
+  private ConstraintSet<Pair> retrieveConstraintSet(UnifyContext context) {
+    this.loadKeyStorage(context);
+    return ConstraintSet.fromSerial(this.constraintSet, context, Pair.class, keyStorage);
+  }
+
+  @JsonIgnore
+  private ConstraintSet<UnifyPair> retrieveUnifyConstraintSet(UnifyContext context) {
+    this.loadKeyStorage(context);
+    return ConstraintSet.fromSerial(this.unifyConstraintSet, context, UnifyPair.class, keyStorage);
+  }
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketServer socketServer) {
+    socketServer.sendMessage(webSocket, "You requested a unify! Please wait until I calculated everything...");
+    System.out.println("Client " + webSocket.<SocketServer.SocketData>getAttachment().id + " requested a unification. Starting now...");
+
+    try {
+      var placeholderRegistry = new PlaceholderRegistry();
+      ArrayList<String> existingPlaceholders = (ArrayList) this.placeholders.getOf(ArrayList.class);
+      existingPlaceholders.forEach(placeholderRegistry::addPlaceholder);
+
+      var unifyContext = new UnifyContext(Writer.nullWriter(), false, true,
+        new UnifyResultModel(new ConstraintSet<>(), new FiniteClosure(new HashSet<>(), null, placeholderRegistry)),
+        new UnifyTaskModel(), ForkJoinPool.commonPool(), placeholderRegistry
+      );
+
+      this.factoryplaceholders.stream()
+        .map(p -> (PlaceholderType)UnifyType.fromSerial(p, unifyContext))
+        .forEach(placeholderRegistry.UnifyTypeFactory_PLACEHOLDERS::add);
+
+
+      // start the unification algorithm from the received data
+      IFiniteClosure finiteClosure = this.retrieveFiniteClosure(unifyContext);
+      ConstraintSet<Pair> constraintSet = this.retrieveConstraintSet(unifyContext);
+      ConstraintSet<UnifyPair> unifyConstraintSet = this.retrieveUnifyConstraintSet(unifyContext);
+
+      var resultModel = new UnifyResultModel(constraintSet, finiteClosure);
+      UnifyResultListenerImpl resultListener = new UnifyResultListenerImpl();
+      resultModel.addUnifyResultListener(resultListener);
+
+      TypeUnify.unifyParallel(
+        unifyConstraintSet.getUndConstraints(),
+        unifyConstraintSet.getOderConstraints(),
+        finiteClosure,
+        unifyContext.newWithResultModel(resultModel)
+      );
+
+      var resultSets = resultListener.getResults();
+
+      System.out.println("Finished unification for client " + webSocket.<SocketServer.SocketData>getAttachment().id);
+      socketServer.sendMessage(webSocket, "Unification finished. Found " + resultSets.size() + " result sets");
+
+      if (webSocket.isOpen()) {
+        UnifyResultPacket resultPacket = UnifyResultPacket.create(resultSets);
+        webSocket.send(PacketContainer.serialize(resultPacket));
+      }
+    } catch (Exception e) {
+      System.err.println(e);
+      SocketServer.log.error("e: ", e);
+    }
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/UnifyResultPacket.java

@@ -0,0 +1,43 @@
+package de.dhbwstuttgart.server.packet;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import de.dhbwstuttgart.server.SocketClient;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.ISerialNode;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.result.ResultSet;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import java.util.List;
+import org.java_websocket.WebSocket;
+
+/**
+ * A packet to send all calculated data from the unification algorithm back to the client
+ */
+public class UnifyResultPacket implements IServerToClientPacket {
+
+  public SerialList<ISerialNode> results;
+  public SerialMap keyStorage;
+
+  public static UnifyResultPacket create(List<ResultSet> resultSets) {
+    UnifyResultPacket serialized = new UnifyResultPacket();
+    KeyStorage keyStorage = new KeyStorage();
+    serialized.results = SerialList.fromMapped(resultSets, resultSet -> resultSet.toSerial(keyStorage));
+    serialized.keyStorage = keyStorage.toSerial(keyStorage);
+    return serialized;
+  }
+
+  @JsonIgnore
+  public List<ResultSet> getResultSet(UnifyContext context) {
+    return this.results.assertListOfMaps().stream()
+      .map(resultData -> ResultSet.fromSerial(resultData, context)).toList();
+  }
+
+  @JsonIgnore
+  public void onHandle(WebSocket webSocket, SocketClient socketClient) {
+    System.out.println("[socket] Received unify result");
+    socketClient.setUnifyResultSets(this);
+  }
+
+
+}

src/main/java/de/dhbwstuttgart/server/packet/dataContainers/ISerializableData.java

@@ -0,0 +1,16 @@
+package de.dhbwstuttgart.server.packet.dataContainers;
+
+import de.dhbwstuttgart.exceptions.NotImplementedException;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.ISerialNode;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+
+public interface ISerializableData {
+
+  public abstract ISerialNode toSerial(KeyStorage keyStorage);
+
+  public static Object fromSerial(SerialMap data, UnifyContext context) {
+    throw new NotImplementedException("Missing implementation of \"fromSerial\" for a serializable element");
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/dataContainers/KeyStorage.java

@@ -0,0 +1,103 @@
+package de.dhbwstuttgart.server.packet.dataContainers;
+
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class KeyStorage implements ISerializableData {
+
+  /**
+   *  Store a unique identifier for every element, so it can be referenced in the json
+   */
+  protected AtomicInteger identifierCount = new AtomicInteger();
+  /**
+   *  Store the serialized element per identifier when serializing
+   */
+  protected SerialMap serializedElements = new SerialMap();
+  /**
+   *  Store the unserialized element per identifier when unserializing
+   */
+  protected Map<String, ISerializableData> unserializedElements = new HashMap<>();
+
+
+  /**
+   *  Retrieve or generate a new identifier for a constraint
+   */
+  public String getIdentifier() {
+    return this.identifierCount.incrementAndGet() + "_";
+  }
+
+  /**
+   *  Checks if the given element identifier belongs to an element that was already serialized
+   */
+  public boolean isAlreadySerialized(String identifier) {
+    return this.serializedElements.containsKey(identifier);
+  }
+
+  /**
+   *  Checks if the given element identifier belongs to a element that was already unserialized
+   */
+  public boolean isAlreadyUnserialized(String identifier) {
+    return this.unserializedElements.containsKey(identifier);
+  }
+
+  /**
+   *  Register a serialized element to prevent it from being serialized again
+   */
+  public void putSerialized(String identifier, SerialMap serializedElement) {
+    this.serializedElements.put(identifier, serializedElement);
+  }
+
+  /**
+   *  Retrieve a serialized element
+   */
+  public SerialMap getSerialized(String identifier) {
+    if (!this.serializedElements.containsKey(identifier)) {
+      throw new RuntimeException("No serialized element of identifier " + identifier + " available to get");
+    }
+    return this.serializedElements.getMap(identifier);
+  }
+
+  /**
+   *  Register an unserialized element to prevent it from being unserialized again
+   */
+  public void putUnserialized(String identifier, ISerializableData element) {
+    this.unserializedElements.put(identifier, element);
+  }
+
+  /**
+   *  Retrieve an unserialized element
+   */
+  public <T extends ISerializableData> T getUnserialized(String identifier, Class<T> target) {
+    if (!this.unserializedElements.containsKey(identifier)) {
+      throw new RuntimeException("No unserialized element of identifier " + identifier + " available to get");
+    }
+    var element = this.unserializedElements.get(identifier);
+    if (target.isInstance(element)) {
+      return (T) element;
+    }
+    throw new RuntimeException("Failed to get unserialized element from KeyStorage. Expected instance of " +
+      target.getName() + " but found " + element.getClass().getName());
+  }
+
+  @Override
+  public SerialMap toSerial(KeyStorage keyStorage) {
+    SerialMap serialized = new SerialMap();
+    serialized.put("serializedElements", this.serializedElements);
+    return serialized;
+  }
+
+  public static KeyStorage fromSerial(SerialMap data, UnifyContext context) {
+    var serializedConstraintsData = data.getMap("serializedElements");
+    var constraintContext = new KeyStorage();
+    for (var entry : serializedConstraintsData.entrySet()) {
+      if (entry.getValue() instanceof SerialMap valueMap) {
+        constraintContext.putSerialized(entry.getKey(), valueMap);
+      }
+    }
+    return constraintContext;
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/dataContainers/serialized/ISerialNode.java

@@ -0,0 +1,31 @@
+package de.dhbwstuttgart.server.packet.dataContainers.serialized;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+
+
+/**
+ * Use the following classes for an intermediate serialized tree structure
+ */
+@JsonTypeInfo(
+  use = JsonTypeInfo.Id.NAME,
+  include = JsonTypeInfo.As.PROPERTY,
+  property = "_t"
+)
+@JsonSubTypes({
+  @JsonSubTypes.Type(value = SerialMap.class, name = "m"),
+  @JsonSubTypes.Type(value = SerialList.class, name = "l"),
+  @JsonSubTypes.Type(value = SerialValue.class, name = "v"),
+  @JsonSubTypes.Type(value = SerialUUID.class, name = "u")
+})
+public interface ISerialNode {
+
+  default <T extends ISerialNode> T assertType(Class<T> type) {
+    if (type.isInstance(this)) {
+      return (T) this;
+    }
+    throw new RuntimeException("Expected ISerialNode to be of type " + type.getName()
+      + " but found " + this.getClass().getName() + " instead");
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/dataContainers/serialized/SerialList.java

@@ -0,0 +1,74 @@
+package de.dhbwstuttgart.server.packet.dataContainers.serialized;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.function.Function;
+import java.util.stream.Stream;
+
+public class SerialList<I extends ISerialNode> extends ArrayList<I> implements ISerialNode {
+  public SerialList() {}
+  public SerialList(Collection<I> data) {
+    this.addAll(data);
+  }
+  public SerialList(Stream<I> data) {
+    this(data.toList());
+  }
+  public SerialList(I[] data) {
+    this(Arrays.stream(data).toList());
+  }
+
+  @SafeVarargs
+  @JsonIgnore
+  public static <A extends ISerialNode> ArrayList<A> from(A ...values) {
+    ArrayList<A> list = new SerialList<>();
+    Collections.addAll(list, values);
+    return list;
+  }
+  @JsonIgnore
+  public static <A,B extends ISerialNode> SerialList<B> fromMapped(Stream<A> data, Function<A,B> mapper) {
+    return new SerialList<>(data.map(mapper).toList());
+  }
+  @JsonIgnore
+  public static <A,B extends ISerialNode> SerialList<B> fromMapped(Collection<A> data, Function<A,B> mapper) {
+    return SerialList.fromMapped(data.stream(), mapper);
+  }
+  @JsonIgnore
+  public static <A,B extends ISerialNode> SerialList<B> fromMapped(A[] data, Function<A,B> mapper) {
+    return SerialList.fromMapped(Arrays.stream(data), mapper);
+  }
+
+  @JsonIgnore
+  public SerialList<SerialMap> assertListOfMaps() {
+    if (this.isEmpty() || this.get(0) instanceof SerialMap) {
+      return (SerialList<SerialMap>) this;
+    }
+    throw new RuntimeException("Required List to contain SerialMap elements but condition failed");
+  }
+
+  @JsonIgnore
+  public SerialList<SerialList<?>> assertListOfLists() {
+    if (this.isEmpty() || this.get(0) instanceof SerialList) {
+      return (SerialList<SerialList<?>>) this;
+    }
+    throw new RuntimeException("Required List to contain SerialList elements but condition failed");
+  }
+
+  @JsonIgnore
+  public SerialList<SerialValue<?>> assertListOfValues() {
+    if (this.isEmpty() || this.get(0) instanceof SerialValue) {
+      return (SerialList<SerialValue<?>>) this;
+    }
+    throw new RuntimeException("Required List to contain SerialValue elements but condition failed");
+  }
+
+  @JsonIgnore
+  public SerialList<SerialUUID> assertListOfUUIDs() {
+    if (this.isEmpty() || this.get(0) instanceof SerialUUID) {
+      return (SerialList<SerialUUID>) this;
+    }
+    throw new RuntimeException("Required List to contain SerialUUID elements but condition failed");
+  }
+}

src/main/java/de/dhbwstuttgart/server/packet/dataContainers/serialized/SerialMap.java

@@ -0,0 +1,84 @@
+package de.dhbwstuttgart.server.packet.dataContainers.serialized;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import java.util.HashMap;
+import java.util.Map;
+import javax.annotation.Nullable;
+
+public class SerialMap extends HashMap<String, ISerialNode> implements ISerialNode {
+
+  public SerialMap() {
+    super();
+  }
+
+  public SerialMap(Map<String, ISerialNode> data) {
+    super(data);
+  }
+
+  @JsonIgnore
+  public void put(String key, Boolean value) {
+    this.put(key, new SerialValue<>(value));
+  }
+
+  @JsonIgnore
+  public void put(String key, String value) {
+    this.put(key, new SerialValue<>(value));
+  }
+
+  @JsonIgnore
+  public void put(String key, Number value) {
+    this.put(key, new SerialValue<>(value));
+  }
+
+  @JsonIgnore
+  private <T> T get(String key, Class<T> expectedType) {
+    if (!this.containsKey(key)) {
+      throw new RuntimeException("Missing required value " + key + " in ObjectMap");
+    }
+    var element = this.get(key);
+    if (element != null && element.getClass() != expectedType) {
+      throw new RuntimeException(
+        "Required value " + key + " to be of type " + expectedType.getName() + " but found " + element.getClass().getName()
+      );
+    }
+    return (T)element;
+  }
+
+  @JsonIgnore
+  public SerialList<?> getList(String key) {
+    return this.get(key, SerialList.class);
+  }
+
+  @Nullable
+  @JsonIgnore
+  public SerialList<?> getListOrNull(String key) {
+    return this.containsKey(key) ? this.getList(key) : null;
+  }
+
+  @JsonIgnore
+  public SerialMap getMap(String key) {
+    return this.get(key, SerialMap.class);
+  }
+
+  @Nullable
+  @JsonIgnore
+  public SerialMap getMapOrNull(String key) {
+    return this.containsKey(key) ? this.getMap(key) : null;
+  }
+
+  @JsonIgnore
+  public SerialValue<?> getValue(String key) {
+    return this.get(key, SerialValue.class);
+  }
+
+  @JsonIgnore
+  public SerialUUID getUUID(String key) {
+    return this.get(key, SerialUUID.class);
+  }
+
+  @Nullable
+  @JsonIgnore
+  public SerialUUID getUUIDOrNull(String key) {
+    return this.containsKey(key) ? this.getUUID(key) : null;
+  }
+}

src/main/java/de/dhbwstuttgart/server/packet/dataContainers/serialized/SerialUUID.java

@@ -0,0 +1,13 @@
+package de.dhbwstuttgart.server.packet.dataContainers.serialized;
+
+public class SerialUUID implements ISerialNode {
+
+  public String uuid;
+
+  public SerialUUID() {}
+
+  public SerialUUID(String uuid) {
+    this.uuid = uuid;
+  }
+
+}

src/main/java/de/dhbwstuttgart/server/packet/dataContainers/serialized/SerialValue.java

@@ -0,0 +1,28 @@
+package de.dhbwstuttgart.server.packet.dataContainers.serialized;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+public class SerialValue<T> implements ISerialNode {
+  public T value;
+  public static final SerialValue<Object> NULL = new SerialValue<>(null);
+
+  public SerialValue() {}
+
+  public SerialValue(T value) {
+    this.value = value;
+  }
+
+  @JsonIgnore
+  public <A> SerialValue<A> assertValueOf(Class<A> targetClass) {
+    if (this.value == null || targetClass.isInstance(this.value)) {
+      return (SerialValue<A>) this;
+    }
+    throw new RuntimeException("Required Value to contain " + targetClass.getName() + " value but condition failed on" +
+      " type " + this.value.getClass().getName());
+  }
+
+  @JsonIgnore
+  public <A> A getOf(Class<A> targetClass) {
+    return this.assertValueOf(targetClass).value;
+  }
+}

src/main/java/de/dhbwstuttgart/syntaxtree/factory/NameGenerator.java

@@ -1,5 +1,8 @@
 package de.dhbwstuttgart.syntaxtree.factory;
 
+import de.dhbwstuttgart.core.JavaTXCompiler;
+import de.dhbwstuttgart.core.JavaTXServer;
+
 public class NameGenerator {
 
     private static String strNextName = "A";
@@ -26,7 +29,11 @@ public class NameGenerator {
     
         // n�chster Name berechnen und in strNextName speichern        
         inc( strNextName.length() - 1 );
-        
+
+        if (JavaTXServer.isRunning) {
+            throw new RuntimeException("Using the NameGenerator on a server is not allowed");
+        }
+        JavaTXCompiler.defaultClientPlaceholderRegistry.addPlaceholder(strReturn);
         return strReturn;        
     }
 

src/main/java/de/dhbwstuttgart/syntaxtree/factory/UnifyTypeFactory.java

@@ -1,5 +1,6 @@
 package de.dhbwstuttgart.syntaxtree.factory;
 
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
 import java.io.Writer;
 import java.lang.reflect.Modifier;
 import java.util.*;
@@ -31,9 +32,13 @@ import org.antlr.v4.runtime.Token;
 
 public class UnifyTypeFactory {
 	
-	private static ArrayList<PlaceholderType> PLACEHOLDERS = new ArrayList<>(); 
+    public static FiniteClosure generateFC(
-
+      List<ClassOrInterface> fromClasses,
-    public static FiniteClosure generateFC(List<ClassOrInterface> fromClasses, Writer logFile, ClassLoader classLoader, JavaTXCompiler compiler) throws ClassNotFoundException {
+      Writer logFile,
+      ClassLoader classLoader,
+      JavaTXCompiler compiler,
+      PlaceholderRegistry placeholderRegistry
+    ) throws ClassNotFoundException {
         /*
         Die transitive Hülle muss funktionieren.
         Man darf schreiben List<A> extends AL<A>
@@ -44,7 +49,7 @@ public class UnifyTypeFactory {
         Generell dürfen sie immer die gleichen Namen haben.
         TODO: die transitive Hülle bilden
          */
-        return new FiniteClosure(FCGenerator.toUnifyFC(compiler, fromClasses, classLoader), logFile, compiler);
+        return new FiniteClosure(FCGenerator.toUnifyFC(compiler, fromClasses, classLoader, placeholderRegistry), logFile, compiler, placeholderRegistry);
     }
 
     public static UnifyPair generateSmallerPair(UnifyType tl, UnifyType tr, SourceLoc location){
@@ -67,23 +72,23 @@ public class UnifyTypeFactory {
      * Convert from
      * ASTType -> UnifyType
      */
-    public static UnifyType convert(JavaTXCompiler compiler, RefTypeOrTPHOrWildcardOrGeneric t, Boolean innerType){
+    public static UnifyType convert(JavaTXCompiler compiler, RefTypeOrTPHOrWildcardOrGeneric t, Boolean innerType, PlaceholderRegistry placeholderRegistry){
         if (t instanceof GenericRefType){
-            return UnifyTypeFactory.convert(compiler, (GenericRefType)t, innerType);
+            return UnifyTypeFactory.convert(compiler, (GenericRefType)t, innerType, placeholderRegistry);
         } else if (t instanceof TypePlaceholder){
-            return UnifyTypeFactory.convert(compiler, (TypePlaceholder)t, innerType);
+            return UnifyTypeFactory.convert(compiler, (TypePlaceholder)t, innerType, placeholderRegistry);
         } else if (t instanceof ExtendsWildcardType){
-            return UnifyTypeFactory.convert(compiler, (ExtendsWildcardType)t, innerType);
+            return UnifyTypeFactory.convert(compiler, (ExtendsWildcardType)t, innerType, placeholderRegistry);
         } else if (t instanceof SuperWildcardType) {
-            return UnifyTypeFactory.convert(compiler, (SuperWildcardType) t, innerType);
+            return UnifyTypeFactory.convert(compiler, (SuperWildcardType) t, innerType, placeholderRegistry);
         } else if (t instanceof RefType){
-            return UnifyTypeFactory.convert(compiler, (RefType)t, innerType);
+            return UnifyTypeFactory.convert(compiler, (RefType)t, innerType, placeholderRegistry);
         }
         //Es wurde versucht ein Typ umzuwandeln, welcher noch nicht von der Factory abgedeckt ist
         throw new NotImplementedException("Der Typ "+t+" kann nicht umgewandelt werden");
     }
 
-    public static UnifyType convert(JavaTXCompiler compiler, RefType t, Boolean innerType){
+    public static UnifyType convert(JavaTXCompiler compiler, RefType t, Boolean innerType, PlaceholderRegistry placeholderRegistry){
         //Check if it is a FunN Type:
         Pattern p = Pattern.compile("Fun(\\d+)[$][$]");
         Matcher m = p.matcher(t.getName().toString());
@@ -91,76 +96,76 @@ public class UnifyTypeFactory {
         if(b){
             Integer N = Integer.valueOf(m.group(1));
             if((N + 1) == t.getParaList().size()){
-                return convertFunN(compiler, t.getParaList(), false);
+                return convertFunN(compiler, t.getParaList(), false, placeholderRegistry);
             }
         }
         UnifyType ret;
         List<UnifyType> params = new ArrayList<>();
         if (t.getParaList() != null) {
             for (RefTypeOrTPHOrWildcardOrGeneric pT : t.getParaList()) {
-                params.add(UnifyTypeFactory.convert(compiler, pT, true));
+                params.add(UnifyTypeFactory.convert(compiler, pT, true, placeholderRegistry));
             }
         }
 
         var clazz = compiler.getClass(t.getName());
         if (clazz != null && clazz.isInterface() && clazz.isFunctionalInterface()) {
             var method = clazz.getMethods().stream().filter(x -> Modifier.isAbstract(x.modifier)).findFirst().orElseThrow();
-            var methodParams = method.getParameterList().getFormalparalist().stream().map(x -> convert(compiler, x.getType(), true)).toList();
+            var methodParams = method.getParameterList().getFormalparalist().stream().map(x -> convert(compiler, x.getType(), true, placeholderRegistry)).toList();
             var generics = StreamSupport.stream(clazz.getGenerics().spliterator(), false).map(GenericTypeVar::getName).toList();
-            return new FunInterfaceType(t.getName().toString(), new TypeParams(params), methodParams, convert(compiler, method.getReturnType(), true), generics);
+            return new FunInterfaceType(t.getName().toString(), new TypeParams(params), methodParams, convert(compiler, method.getReturnType(), true, placeholderRegistry), generics);
         }
 
         return new ReferenceType(t.getName().toString(),new TypeParams(params));
     }
 
-    public static UnifyType convertFunN(JavaTXCompiler compiler, List<RefTypeOrTPHOrWildcardOrGeneric> paraList, Boolean innerType){
+    public static UnifyType convertFunN(JavaTXCompiler compiler, List<RefTypeOrTPHOrWildcardOrGeneric> paraList, Boolean innerType, PlaceholderRegistry placeholderRegistry){
         UnifyType ret;
         List<UnifyType> params = new ArrayList<>();
         if(paraList != null && paraList.size() > 0){
             for(RefTypeOrTPHOrWildcardOrGeneric pT : paraList){
-                params.add(UnifyTypeFactory.convert(compiler, pT, false));
+                params.add(UnifyTypeFactory.convert(compiler, pT, false, placeholderRegistry));
             }
         }
         ret = FunNType.getFunNType(new TypeParams(params));
         return ret;
     }
 
-    public static UnifyType convert(JavaTXCompiler compiler, TypePlaceholder tph, Boolean innerType){
+    public static UnifyType convert(JavaTXCompiler compiler, TypePlaceholder tph, Boolean innerType, PlaceholderRegistry placeholderRegistry) {
     	if (tph.getName().equals("AFR")) {
     		System.out.println("XXX"+innerType);
     	}
-    	PlaceholderType ntph = new PlaceholderType(tph.getName(), tph.getVariance());
+    	PlaceholderType ntph = new PlaceholderType(tph.getName(), tph.getVariance(), placeholderRegistry);
     	ntph.setVariance(tph.getVariance());
     	ntph.setOrCons(tph.getOrCons());
     	ntph.setWildcardtable(tph.getWildcardtable());
-    	int in = PLACEHOLDERS.indexOf(ntph);
+    	int in = placeholderRegistry.UnifyTypeFactory_PLACEHOLDERS.indexOf(ntph);
 		if (in == -1) {
-			PLACEHOLDERS.add(ntph);
+        placeholderRegistry.UnifyTypeFactory_PLACEHOLDERS.add(ntph);
 			ntph.setInnerType(innerType);
 			return ntph;
 		}
 		else {
-			 PlaceholderType oldpht = PLACEHOLDERS.get(in);
+			 PlaceholderType oldpht = placeholderRegistry.UnifyTypeFactory_PLACEHOLDERS.get(in);
 			 oldpht.setInnerType(oldpht.isInnerType() || innerType);
 			 return oldpht;
 		}
     }
 
-    public static UnifyType convert(JavaTXCompiler compiler, GenericRefType t, Boolean innerType){
+    public static UnifyType convert(JavaTXCompiler compiler, GenericRefType t, Boolean innerType, PlaceholderRegistry placeholderRegistry){
         return new ReferenceType(t.getParsedName(), true);
     }
 
-    public static UnifyType convert(JavaTXCompiler compiler, WildcardType t, Boolean innerType){
+    public static UnifyType convert(JavaTXCompiler compiler, WildcardType t, Boolean innerType, PlaceholderRegistry placeholderRegistry){
         if(t.isExtends())
-            return new ExtendsType(UnifyTypeFactory.convert(compiler, t.getInnerType(), false));
+            return new ExtendsType(UnifyTypeFactory.convert(compiler, t.getInnerType(), false, placeholderRegistry));
         else if(t.isSuper())
-            return new SuperType(UnifyTypeFactory.convert(compiler, t.getInnerType(), false));
+            return new SuperType(UnifyTypeFactory.convert(compiler, t.getInnerType(), false, placeholderRegistry));
         else throw new NotImplementedException();
     }
 
 
-    public static ConstraintSet<UnifyPair> convert(JavaTXCompiler compiler, ConstraintSet<Pair> constraints) {
+    public static ConstraintSet<UnifyPair> convert(JavaTXCompiler compiler, ConstraintSet<Pair> constraints, PlaceholderRegistry placeholderRegistry) {
-        return constraints.map(c -> UnifyTypeFactory.convert(compiler, c));
+        return constraints.map(c -> UnifyTypeFactory.convert(compiler, c, placeholderRegistry));
     }
 
     //NEVER USED
@@ -171,30 +176,30 @@ public class UnifyTypeFactory {
     //	return unifyPairConstraint;
     //}
 
-    public static UnifyPair convert(JavaTXCompiler compiler, Pair p) {
+    public static UnifyPair convert(JavaTXCompiler compiler, Pair p, PlaceholderRegistry placeholderRegistry) {
     	UnifyPair ret = null;
         if(p.GetOperator().equals(PairOperator.SMALLERDOT)) {
-             ret = generateSmallerDotPair(UnifyTypeFactory.convert(compiler, p.TA1, false)
+             ret = generateSmallerDotPair(UnifyTypeFactory.convert(compiler, p.TA1, false, placeholderRegistry)
-                    , UnifyTypeFactory.convert(compiler, p.TA2, false), p.getLocation());
+                    , UnifyTypeFactory.convert(compiler, p.TA2, false, placeholderRegistry), p.getLocation());
             //return ret;
         }else if(p.GetOperator().equals(PairOperator.SMALLERNEQDOT)) {
-             ret = generateSmallNotEqualDotPair(UnifyTypeFactory.convert(compiler, p.TA1, false)
+             ret = generateSmallNotEqualDotPair(UnifyTypeFactory.convert(compiler, p.TA1, false, placeholderRegistry)
-                    , UnifyTypeFactory.convert(compiler, p.TA2, false), p.getLocation());
+                    , UnifyTypeFactory.convert(compiler, p.TA2, false, placeholderRegistry), p.getLocation());
             //return ret;
         }else if(p.GetOperator().equals(PairOperator.EQUALSDOT)) {
-             ret = generateEqualDotPair(UnifyTypeFactory.convert(compiler, p.TA1, false)
+             ret = generateEqualDotPair(UnifyTypeFactory.convert(compiler, p.TA1, false, placeholderRegistry)
-                    , UnifyTypeFactory.convert(compiler, p.TA2, false), p.getLocation());
+                    , UnifyTypeFactory.convert(compiler, p.TA2, false, placeholderRegistry), p.getLocation());
             //return ret;
         }else if(p.GetOperator().equals(PairOperator.SMALLER)){
-            ret =  generateSmallerPair(UnifyTypeFactory.convert(compiler, p.TA1, false),
+            ret =  generateSmallerPair(UnifyTypeFactory.convert(compiler, p.TA1, false, placeholderRegistry),
-                    UnifyTypeFactory.convert(compiler, p.TA2, false), p.getLocation());
+                    UnifyTypeFactory.convert(compiler, p.TA2, false, placeholderRegistry), p.getLocation());
         }else            throw new NotImplementedException();
         UnifyType lhs, rhs;
         if (((lhs = ret.getLhsType()) instanceof PlaceholderType) 
         		&& ((PlaceholderType)lhs).isWildcardable() 
         		&&	(rhs = ret.getLhsType()) instanceof PlaceholderType) {
         	if (lhs.getName().equals("AQ")) {
-        		System.out.println("");
+        		// System.out.println("");
         	}
         	((PlaceholderType)rhs).enableWildcardtable();
         }
@@ -203,7 +208,7 @@ public class UnifyTypeFactory {
         		&& ((PlaceholderType)rhs).isWildcardable()
         		&&	(lhs = ret.getLhsType()) instanceof PlaceholderType) {
         	if (rhs.getName().equals("AQ")) {
-        		System.out.println("");
+        		// System.out.println("");
         	}
         	((PlaceholderType)lhs).enableWildcardtable();
         }
@@ -214,16 +219,16 @@ public class UnifyTypeFactory {
      * Convert from
      * UnifyType -> ASTType
      */
-    public static Set<ResultPair> convert(Set<UnifyPair> unifyPairSet, Map<String,TypePlaceholder> tphs) {
+    public static Set<ResultPair> convert(Set<UnifyPair> unifyPairSet, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
         return unifyPairSet.stream().map(
-                unifyPair -> convert(unifyPair, tphs))
+                unifyPair -> convert(unifyPair, tphs, placeholderRegistry))
                         .collect(Collectors.toSet());
     }
 
-    public static ResultPair convert(UnifyPair mp, Map<String,TypePlaceholder> tphs) {
+    public static ResultPair convert(UnifyPair mp, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
     	if (mp == null) { return null;} //kann bei basePairs passieren
-        RefTypeOrTPHOrWildcardOrGeneric tl = UnifyTypeFactory.convert(mp.getLhsType(), tphs);
+        RefTypeOrTPHOrWildcardOrGeneric tl = UnifyTypeFactory.convert(mp.getLhsType(), tphs, placeholderRegistry);
-        RefTypeOrTPHOrWildcardOrGeneric tr = UnifyTypeFactory.convert(mp.getRhsType(), tphs);
+        RefTypeOrTPHOrWildcardOrGeneric tr = UnifyTypeFactory.convert(mp.getRhsType(), tphs, placeholderRegistry);
         if(tl instanceof TypePlaceholder){
             if(tr instanceof TypePlaceholder) {
 
@@ -232,7 +237,7 @@ public class UnifyTypeFactory {
                     //Einfach ignorieren TODO: Das hier muss ausgebessert werden:
                     //return new PairTPHequalRefTypeOrWildcardType((TypePlaceholder)tl, ASTFactory.createObjectType());
                 }else{
-                    return new PairTPHsmallerTPH((TypePlaceholder)tl, (TypePlaceholder)tr, convert(mp.getBasePair(), tphs));
+                    return new PairTPHsmallerTPH((TypePlaceholder)tl, (TypePlaceholder)tr, convert(mp.getBasePair(), tphs, placeholderRegistry));
                 }
             }else if(tr instanceof RefType){
                 return new PairTPHequalRefTypeOrWildcardType((TypePlaceholder)tl, (RefType) tr);
@@ -244,51 +249,51 @@ public class UnifyTypeFactory {
         }else return new PairNoResult(tl, tr);//throw new NotImplementedException();
     }
 
-    public static RefTypeOrTPHOrWildcardOrGeneric convert(ReferenceType t, Map<String,TypePlaceholder> tphs) {
+    public static RefTypeOrTPHOrWildcardOrGeneric convert(ReferenceType t, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
         if(JavaClassName.Void.equals(t.getName()))return new Void(new NullToken());
         if (t.isGenTypeVar()) return new GenericRefType(t.getName(),new NullToken());
-        RefType ret = new RefType(new JavaClassName(t.getName()),convert(t.getTypeParams(), tphs),new NullToken());
+        RefType ret = new RefType(new JavaClassName(t.getName()),convert(t.getTypeParams(), tphs, placeholderRegistry),new NullToken());
         return ret;
     }
 
-    public static RefTypeOrTPHOrWildcardOrGeneric convert(FunNType t, Map<String,TypePlaceholder> tphs) {
+    public static RefTypeOrTPHOrWildcardOrGeneric convert(FunNType t, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
-        RefType ret = new RefType(new JavaClassName(t.getName()), convert(t.getTypeParams(), tphs), new NullToken());
+        RefType ret = new RefType(new JavaClassName(t.getName()), convert(t.getTypeParams(), tphs, placeholderRegistry), new NullToken());
         return ret;
     }
 
-    public static RefTypeOrTPHOrWildcardOrGeneric convert(SuperType t, Map<String,TypePlaceholder> tphs) {
+    public static RefTypeOrTPHOrWildcardOrGeneric convert(SuperType t, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
-        RefTypeOrTPHOrWildcardOrGeneric innerType = convert(t.getSuperedType(), tphs);
+        RefTypeOrTPHOrWildcardOrGeneric innerType = convert(t.getSuperedType(), tphs, placeholderRegistry);
         return new SuperWildcardType(innerType, new NullToken());
     }
 
-    public static RefTypeOrTPHOrWildcardOrGeneric convert(ExtendsType t, Map<String,TypePlaceholder> tphs) {
+    public static RefTypeOrTPHOrWildcardOrGeneric convert(ExtendsType t, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
-        RefTypeOrTPHOrWildcardOrGeneric innerType = convert(t.getExtendedType(), tphs);
+        RefTypeOrTPHOrWildcardOrGeneric innerType = convert(t.getExtendedType(), tphs, placeholderRegistry);
         return new ExtendsWildcardType(innerType, new NullToken());
     }
 
-    public static RefTypeOrTPHOrWildcardOrGeneric convert(PlaceholderType t, Map<String,TypePlaceholder> tphs) {
+    public static RefTypeOrTPHOrWildcardOrGeneric convert(PlaceholderType t, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
         TypePlaceholder ret = tphs.get(t.getName());
         if(ret == null){ //Dieser TPH wurde vom Unifikationsalgorithmus erstellt
-            ret = TypePlaceholder.fresh(new NullToken());
+            ret = TypePlaceholder.fresh(new NullToken(), placeholderRegistry);
             tphs.put(t.getName(), ret);
         }
         ret.setVariance(t.getVariance());
         return ret;
     }
 
-    public static RefTypeOrTPHOrWildcardOrGeneric convert(UnifyType t, Map<String,TypePlaceholder> tphs) {
+    public static RefTypeOrTPHOrWildcardOrGeneric convert(UnifyType t, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
-        if(t instanceof FunNType)return convert((FunNType) t, tphs);
+        if(t instanceof FunNType)return convert((FunNType) t, tphs, placeholderRegistry);
-        if(t instanceof ReferenceType)return convert((ReferenceType) t, tphs);
+        if(t instanceof ReferenceType)return convert((ReferenceType) t, tphs, placeholderRegistry);
-        if(t instanceof SuperType)return convert((SuperType) t, tphs);
+        if(t instanceof SuperType)return convert((SuperType) t, tphs, placeholderRegistry);
-        if(t instanceof ExtendsType)return convert((ExtendsType) t, tphs);
+        if(t instanceof ExtendsType)return convert((ExtendsType) t, tphs, placeholderRegistry);
-        if(t instanceof PlaceholderType)return convert((PlaceholderType) t, tphs);
+        if(t instanceof PlaceholderType)return convert((PlaceholderType) t, tphs, placeholderRegistry);
         throw new NotImplementedException("Der Typ "+t+" kann nicht umgewandelt werden");
     }
 
-    private static List<RefTypeOrTPHOrWildcardOrGeneric> convert(TypeParams typeParams, Map<String,TypePlaceholder> tphs) {
+    private static List<RefTypeOrTPHOrWildcardOrGeneric> convert(TypeParams typeParams, Map<String,TypePlaceholder> tphs, PlaceholderRegistry placeholderRegistry) {
         List<RefTypeOrTPHOrWildcardOrGeneric> ret = new ArrayList<>();
         for(UnifyType uT : typeParams){
-            RefTypeOrTPHOrWildcardOrGeneric toAdd = convert(uT, tphs);
+            RefTypeOrTPHOrWildcardOrGeneric toAdd = convert(uT, tphs, placeholderRegistry);
             ret.add(toAdd);
         }
         return ret;

src/main/java/de/dhbwstuttgart/syntaxtree/type/ExtendsWildcardType.java

@@ -1,8 +1,13 @@
 package de.dhbwstuttgart.syntaxtree.type;
 
 
+import de.dhbwstuttgart.parser.NullToken;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.syntaxtree.ASTVisitor;
 import de.dhbwstuttgart.typeinference.result.ResultSetVisitor;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import org.antlr.v4.runtime.Token;
 
 import java.util.Objects;
@@ -15,7 +20,7 @@ import java.util.Objects;
  * 
  */
 
-public class ExtendsWildcardType extends WildcardType{
+public class ExtendsWildcardType extends WildcardType implements ISerializableData {
 	
 	/**
 	* Author: Arne Lüdtke<br/>
@@ -68,4 +73,22 @@ public class ExtendsWildcardType extends WildcardType{
 		ExtendsWildcardType that = (ExtendsWildcardType) o;
 		return that.innerType.equals(this.innerType);
 	}
+
+	@Override
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		serialized.put("innerType", this.innerType.toSerial(keyStorage));
+
+		// create the wrapper and put this as the object
+		var serializedWrapper = super.toSerial(keyStorage).assertType(SerialMap.class);
+		serializedWrapper.put("object", serialized);
+		return serializedWrapper;
+	}
+
+	public static ExtendsWildcardType fromSerial(SerialMap data, UnifyContext context) {
+		return new ExtendsWildcardType(
+			RefTypeOrTPHOrWildcardOrGeneric.fromSerial(data.getMap("innerType"), context),
+			new NullToken()
+		);
+	}
 }

src/main/java/de/dhbwstuttgart/syntaxtree/type/GenericRefType.java

@@ -1,57 +1,77 @@
 package de.dhbwstuttgart.syntaxtree.type;
 
+import de.dhbwstuttgart.parser.NullToken;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.syntaxtree.ASTVisitor;
 import de.dhbwstuttgart.typeinference.result.ResultSetVisitor;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import org.antlr.v4.runtime.Token;
 
 import java.util.Objects;
 
-public class GenericRefType extends RefTypeOrTPHOrWildcardOrGeneric
+public class GenericRefType extends RefTypeOrTPHOrWildcardOrGeneric implements ISerializableData {
-{
+  private String name;
-    private String name;
 
-    public GenericRefType(String name, Token offset)
+  public GenericRefType(String name, Token offset) {
-    {
+    super(offset);
-        super(offset);
+    this.name = name;
-        this.name = name;
+  }
-    }
 
-    public String getParsedName(){
+  public String getParsedName() {
-        return name.toString();
+    return name.toString();
-    }
+  }
 
-    @Override
+  @Override
-    public void accept(ASTVisitor visitor) {
+  public void accept(ASTVisitor visitor) {
-        visitor.visit(this);
+    visitor.visit(this);
-    }
+  }
 
-    @Override
+  @Override
-    public <A> A acceptTV(TypeVisitor<A> visitor) {
+  public <A> A acceptTV(TypeVisitor<A> visitor) {
-        return visitor.visit(this);
+    return visitor.visit(this);
-    }
+  }
 
-    @Override
+  @Override
-    public void accept(ResultSetVisitor visitor) {
+  public void accept(ResultSetVisitor visitor) {
-        visitor.visit(this);
+    visitor.visit(this);
-    }
+  }
 
-    @Override
+  @Override
-    public boolean equals(Object o) {
+  public boolean equals(Object o) {
-        if (this == o) return true;
+    if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+    if (o == null || getClass() != o.getClass()) return false;
-        GenericRefType that = (GenericRefType) o;
+    GenericRefType that = (GenericRefType) o;
-        return name.equals(that.name);
+    return name.equals(that.name);
-    }
+  }
 
-    @Override
+  @Override
-    public int hashCode() {
+  public int hashCode() {
-        return Objects.hash(name);
+    return Objects.hash(name);
-    }
+  }
 
-    @Override
+  @Override
-	public String toString()
+  public String toString() {
-	{
+    return "GTV " + this.name;
-		 return "GTV " + this.name;
+  }
-	}
+
+  @Override
+  public SerialMap toSerial(KeyStorage keyStorage) {
+    SerialMap serialized = new SerialMap();
+    serialized.put("name", this.name);
+
+    // create the wrapper and put this as the object
+    var serializedWrapper = super.toSerial(keyStorage).assertType(SerialMap.class);
+    serializedWrapper.put("object", serialized);
+    return serializedWrapper;
+  }
+
+  public static GenericRefType fromSerial(SerialMap data, UnifyContext context) {
+    return new GenericRefType(
+      data.getValue("name").getOf(String.class),
+      new NullToken()
+    );
+  }
 }
 

src/main/java/de/dhbwstuttgart/syntaxtree/type/RefType.java

@@ -1,8 +1,15 @@
 package de.dhbwstuttgart.syntaxtree.type;
 
+import de.dhbwstuttgart.parser.NullToken;
 import de.dhbwstuttgart.parser.scope.JavaClassName;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.ISerialNode;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.syntaxtree.ASTVisitor;
 import de.dhbwstuttgart.typeinference.result.ResultSetVisitor;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import org.antlr.v4.runtime.Token;
 
 import java.util.ArrayList;
@@ -11,122 +18,137 @@ import java.util.List;
 import java.util.Objects;
 
 
-public class RefType extends RefTypeOrTPHOrWildcardOrGeneric
+public class RefType extends RefTypeOrTPHOrWildcardOrGeneric implements ISerializableData {
-{
+  protected final JavaClassName name;
-	protected final JavaClassName name;
+  protected final List<RefTypeOrTPHOrWildcardOrGeneric> parameter;
-    protected final List<RefTypeOrTPHOrWildcardOrGeneric> parameter;
+  /**
-    /**
+   * Ist primitiveFlag auf true, muss beim Codegen dieser Reftype durch
-     * Ist primitiveFlag auf true, muss beim Codegen dieser Reftype durch
+   * den primitiven Datentyp ersetzt werden
-     * den primitiven Datentyp ersetzt werden
+   * <p>
-     *
+   * Bsp: java.lang.Integer mit Flag wird dann zu [int]
-     * Bsp: java.lang.Integer mit Flag wird dann zu [int]
+   */
-     */
+  boolean primitiveFlag = false; // TODO Should be final
-    boolean primitiveFlag = false; // TODO Should be final
 
-    public RefType(JavaClassName fullyQualifiedName, Token offset)
+  public RefType(JavaClassName fullyQualifiedName, Token offset) {
-    {
+    this(fullyQualifiedName, new ArrayList<>(), offset);
-        this(fullyQualifiedName, new ArrayList<>(), offset);
+  }
+
+  public boolean isPrimitive() {
+    return primitiveFlag;
+  }
+
+  @Override
+  public String toString() {
+    String params = "";
+    if (parameter.size() > 0) {
+      params += "<";
+      Iterator<RefTypeOrTPHOrWildcardOrGeneric> it = parameter.iterator();
+      while (it.hasNext()) {
+        RefTypeOrTPHOrWildcardOrGeneric param = it.next();
+        params += param.toString();
+        if (it.hasNext()) params += ", ";
+      }
+      params += ">";
+    }
+    return this.name.toString() + params;
+  }
+
+  @Override
+  public int hashCode() {
+    return this.name.hashCode();//Nur den Name hashen. Sorgt für langsame, aber funktionierende HashMaps
+  }
+
+  public RefType(JavaClassName fullyQualifiedName, List<RefTypeOrTPHOrWildcardOrGeneric> parameter, Token offset) {
+    this(fullyQualifiedName, parameter, offset, false);
+  }
+
+  public RefType(JavaClassName fullyQualifiedName, List<RefTypeOrTPHOrWildcardOrGeneric> parameter, Token offset, boolean primitiveFlag) {
+    super(offset);
+    this.name = (fullyQualifiedName);
+    this.parameter = parameter;
+    this.primitiveFlag = primitiveFlag;
+  }
+
+  public JavaClassName getName() {
+    return name;
+  }
+
+  public List<RefTypeOrTPHOrWildcardOrGeneric> getParaList() {
+    if (this.parameter == null) return new ArrayList<>();
+    return this.parameter;
+  }
+
+  /**
+   * Author: Jrg Buerle<br/>
+   *
+   * @return
+   */
+  public boolean equals(Object obj) {
+    if (!(obj instanceof RefType refObj)) {
+      return false;
     }
 
-    public boolean isPrimitive() {
+    if (!Objects.equals(this.name, refObj.name)) return false;
-        return primitiveFlag;
+    boolean ret = true;
-    }
 
-    @Override
+    //if(!(super.equals(obj))) PL 2020-03-12 muss vll. einkommentiert werden
-    public String toString(){
+    //	return false;
-        String params = "";
+
-        if(parameter.size()>0){
+    if (parameter == null || parameter.size() == 0) {
-            params += "<";
+      ret &= (refObj.getParaList() == null || refObj.getParaList().isEmpty());
-            Iterator<RefTypeOrTPHOrWildcardOrGeneric> it = parameter.iterator();
+    } else {
-            while(it.hasNext()){
+      if (refObj.getParaList() == null) {
-                RefTypeOrTPHOrWildcardOrGeneric param = it.next();
+        ret = false;
-                params += param.toString();
+      } else if (parameter.size() != refObj.getParaList().size()) {
-                if(it.hasNext())params += ", ";
+        ret = false;
-            }
+      } else {
-            params += ">";
+        for (int i = 0; i < parameter.size(); i++) {
+          ret &= parameter.get(i).equals(refObj.getParaList().get(i));
         }
-        return this.name.toString() + params;
+      }
     }
+    return ret;
 
-    @Override
+  }
-	public int hashCode() {
-        return this.name.hashCode();//Nur den Name hashen. Sorgt für langsame, aber funktionierende HashMaps
-	}
 
-    public RefType(JavaClassName fullyQualifiedName, List<RefTypeOrTPHOrWildcardOrGeneric> parameter, Token offset) {
-        this(fullyQualifiedName, parameter, offset, false);
-    }
 
-    public RefType(JavaClassName fullyQualifiedName, List<RefTypeOrTPHOrWildcardOrGeneric> parameter, Token offset, boolean primitiveFlag) {
+  @Override
-        super(offset);
+  public void accept(ASTVisitor visitor) {
-        this.name = (fullyQualifiedName);
+    visitor.visit(this);
-        this.parameter = parameter;
+  }
-        this.primitiveFlag = primitiveFlag;
-    }
 
-    public JavaClassName getName()
+  @Override
-    {
+  public <A> A acceptTV(TypeVisitor<A> visitor) {
-        return name;
+    return visitor.visit(this);
-    }
+  }
 
-    public List<RefTypeOrTPHOrWildcardOrGeneric> getParaList(){
+  @Override
-    	if(this.parameter==null)return new ArrayList<>();
+  public void accept(ResultSetVisitor visitor) {
-    	return this.parameter;
+    visitor.visit(this);
-    }
+  }
 
-    /**
+  @Override
-     * Author: Jrg Buerle<br/>
+  public ISerialNode toSerial(KeyStorage keyStorage) {
-     * @return
+    SerialMap serialized = new SerialMap();
-     */
+    serialized.put("isPrimitive", this.primitiveFlag);
-    public boolean equals(Object obj)
+    serialized.put("name", this.name.toString());
-    {
+    serialized.put("parameters", SerialList.fromMapped(this.parameter, param -> param.toSerial(keyStorage)));
-        if(obj instanceof RefType){
-            if (!Objects.equals(this.name, ((RefType) obj).name)) return false;
-            boolean ret = true;
-            
-            //if(!(super.equals(obj))) PL 2020-03-12 muss vll. einkommentiert werden   
-            //	return false;
-            
-            if(parameter==null || parameter.size()==0){
-                ret &= (((RefType)obj).getParaList()==null || ((RefType)obj).getParaList().size()==0);
-            }
-            else{
-                if(((RefType)obj).getParaList()==null){
-                    ret = false;
-                }
-                else if(parameter.size() != ((RefType)obj).getParaList().size())
-                {
-                	ret = false;
-                }
-                else
-                {
-                	for(int i = 0; i<parameter.size(); i++)
-                	{
-                		ret &= parameter.get(i).equals(((RefType)obj).getParaList().get(i));
-                	}
-                }
-            }
-            return ret;
-        }
-        else{
-            return false;
-        }
-    }
-    	
 
-    @Override
+    // create the wrapper and put this as the object
-    public void accept(ASTVisitor visitor) {
+    var serializedWrapper = super.toSerial(keyStorage).assertType(SerialMap.class);
-        visitor.visit(this);
+    serializedWrapper.put("object", serialized);
-    }
+    return serializedWrapper;
+  }
 
-    @Override
+  public static RefType fromSerial(SerialMap data, UnifyContext context) {
-    public <A> A acceptTV(TypeVisitor<A> visitor) {
+    return new RefType(
-        return visitor.visit(this);
+      new JavaClassName(data.getValue("name").getOf(String.class)),
-    }
+      data.getList("parameters").assertListOfMaps().stream()
-
+        .map(param -> RefTypeOrTPHOrWildcardOrGeneric.fromSerial(param, context))
-    @Override
+        .toList(),
-    public void accept(ResultSetVisitor visitor) {
+      new NullToken(),
-        visitor.visit(this);
+      data.getValue("isPrimitive").getOf(Boolean.class)
-    }
+    );
+  }
 }
 

src/main/java/de/dhbwstuttgart/syntaxtree/type/RefTypeOrTPHOrWildcardOrGeneric.java

@@ -1,11 +1,17 @@
 package de.dhbwstuttgart.syntaxtree.type;
 
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.ISerialNode;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialValue;
 import de.dhbwstuttgart.syntaxtree.ASTVisitor;
 import de.dhbwstuttgart.syntaxtree.SyntaxTreeNode;
 import de.dhbwstuttgart.typeinference.result.ResultSetVisitor;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import org.antlr.v4.runtime.Token;
 
-public abstract class RefTypeOrTPHOrWildcardOrGeneric extends SyntaxTreeNode{
+public abstract class RefTypeOrTPHOrWildcardOrGeneric extends SyntaxTreeNode implements ISerializableData {
     public RefTypeOrTPHOrWildcardOrGeneric(Token offset) {
         super(offset);
     }
@@ -18,5 +24,26 @@ public abstract class RefTypeOrTPHOrWildcardOrGeneric extends SyntaxTreeNode{
     
     @Override
     public abstract boolean equals(Object o);
-    
+
+    @Override
+    public ISerialNode toSerial(KeyStorage keyStorage) {
+        SerialMap serialized = new SerialMap();
+        serialized.put("type", this.getClass().getSimpleName());
+          // we only insert null for the object and expect the child classes to call this and override the value with themselves
+        serialized.put("object", SerialValue.NULL);
+        return serialized;
+    }
+
+    public static RefTypeOrTPHOrWildcardOrGeneric fromSerial(SerialMap data, UnifyContext context) {
+        String type = data.getValue("type").getOf(String.class);
+        SerialMap object = data.getMap("object");
+
+        if      (type.equals(ExtendsWildcardType.class.getSimpleName()))    return ExtendsWildcardType.fromSerial(object, context);
+        else if (type.equals(GenericRefType.class.getSimpleName()))         return GenericRefType.fromSerial(object, context);
+        else if (type.equals(SuperWildcardType.class.getSimpleName()))      return SuperWildcardType.fromSerial(object, context);
+        else if (type.equals(RefType.class.getSimpleName()))                return RefType.fromSerial(object, context);
+        else if (type.equals(Void.class.getSimpleName()))                   return Void.fromSerial(object, context);
+        else if (type.equals(TypePlaceholder.class.getSimpleName()))        return TypePlaceholder.fromSerial(object, context);
+        else throw new RuntimeException("Could not unserialize class of unhandled type " + type);
+    }
 }

src/main/java/de/dhbwstuttgart/syntaxtree/type/SuperWildcardType.java

@@ -1,9 +1,13 @@
 package de.dhbwstuttgart.syntaxtree.type;
 
 
+import de.dhbwstuttgart.parser.NullToken;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.syntaxtree.ASTVisitor;
-import de.dhbwstuttgart.syntaxtree.GenericTypeVar;
 import de.dhbwstuttgart.typeinference.result.ResultSetVisitor;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import org.antlr.v4.runtime.Token;
 
 import java.util.Objects;
@@ -16,7 +20,7 @@ import java.util.Objects;
  * 
  */
 
-public class SuperWildcardType extends WildcardType{
+public class SuperWildcardType extends WildcardType implements ISerializableData {
 
 	/**
 	* Author: Arne Lüdtke<br/>
@@ -80,4 +84,22 @@ public class SuperWildcardType extends WildcardType{
 		SuperWildcardType that = (SuperWildcardType) o;
 		return that.innerType.equals(this.innerType);
 	}
+
+	@Override
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		serialized.put("innerType", this.innerType.toSerial(keyStorage));
+
+		// create the wrapper and put this as the object
+		var serializedWrapper = super.toSerial(keyStorage).assertType(SerialMap.class);
+		serializedWrapper.put("object", serialized);
+		return serializedWrapper;
+	}
+
+	public static SuperWildcardType fromSerial(SerialMap data, UnifyContext context) {
+		return new SuperWildcardType(
+			RefTypeOrTPHOrWildcardOrGeneric.fromSerial(data.getMap("innerType"), context),
+			new NullToken()
+		);
+	}
 }

src/main/java/de/dhbwstuttgart/syntaxtree/type/TypePlaceholder.java

@@ -1,9 +1,12 @@
 package de.dhbwstuttgart.syntaxtree.type;
-import java.util.Hashtable;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 
 import de.dhbwstuttgart.parser.NullToken;
 import de.dhbwstuttgart.syntaxtree.ASTVisitor;
-import de.dhbwstuttgart.syntaxtree.SyntaxTreeNode;
 import de.dhbwstuttgart.syntaxtree.factory.NameGenerator;
 import de.dhbwstuttgart.typeinference.result.ResultSetVisitor;
 import org.antlr.v4.runtime.Token;
@@ -16,7 +19,7 @@ import org.antlr.v4.runtime.Token;
  * @author J�rg B�uerle
  * @version $Date: 2013/06/19 12:45:37 $
  */
-public class TypePlaceholder extends RefTypeOrTPHOrWildcardOrGeneric
+public class TypePlaceholder extends RefTypeOrTPHOrWildcardOrGeneric implements ISerializableData
 {
 	private final String name;
 	
@@ -65,7 +68,12 @@ public class TypePlaceholder extends RefTypeOrTPHOrWildcardOrGeneric
     public static TypePlaceholder fresh(Token position){
 		return new TypePlaceholder(NameGenerator.makeNewName(), position, 0, true);
     }
-    
+
+  public static TypePlaceholder fresh(Token position, PlaceholderRegistry placeholderRegistry){
+    String newName = placeholderRegistry.generateFreshPlaceholderName();
+    return new TypePlaceholder(newName, position, 0, true);
+  }
+
     public static TypePlaceholder fresh(Token position, int variance, boolean wildcardable){
 		return new TypePlaceholder(NameGenerator.makeNewName(), position, variance, wildcardable);
     }
@@ -139,4 +147,26 @@ public class TypePlaceholder extends RefTypeOrTPHOrWildcardOrGeneric
 	public Boolean getWildcardtable() {
 		return wildcardable;
 	}
+
+  @Override
+  public SerialMap toSerial(KeyStorage keyStorage) {
+    SerialMap serialized = new SerialMap();
+    serialized.put("name", this.name);
+    serialized.put("variance", this.variance);
+    serialized.put("wildcardable", this.wildcardable);
+
+    // create the wrapper and put this as the object
+    var serializedWrapper = super.toSerial(keyStorage).assertType(SerialMap.class);
+    serializedWrapper.put("object", serialized);
+    return serializedWrapper;
+  }
+
+  public static TypePlaceholder fromSerial(SerialMap data, UnifyContext context) {
+    return new TypePlaceholder(
+      data.getValue("name").getOf(String.class),
+      new NullToken(),
+      data.getValue("variance").getOf(Integer.class),
+      data.getValue("wildcardable").getOf(Boolean.class)
+    );
+  }
 }

src/main/java/de/dhbwstuttgart/syntaxtree/type/Void.java

@@ -1,14 +1,32 @@
 package de.dhbwstuttgart.syntaxtree.type;
 
+import de.dhbwstuttgart.parser.NullToken;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.ISerialNode;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import org.antlr.v4.runtime.Token;
 
 import de.dhbwstuttgart.parser.scope.JavaClassName;
 
 
-public class Void extends RefType
+public class Void extends RefType implements ISerializableData
 {
     public Void(Token offset) {
         super(JavaClassName.Void, offset);
     }
+
+    @Override
+    public ISerialNode toSerial(KeyStorage keyStorage) {
+        // create the wrapper and put this as the object
+        var serializedWrapper = super.toSerial(keyStorage).assertType(SerialMap.class);
+        serializedWrapper.put("object", new SerialMap());
+        return serializedWrapper;
+    }
+
+    public static Void fromSerial(SerialMap data, UnifyContext context) {
+        return new Void(new NullToken());
+    }
 }
 

src/main/java/de/dhbwstuttgart/typeinference/assumptions/FunNClass.java

@@ -9,13 +9,8 @@ import de.dhbwstuttgart.syntaxtree.Method;
 import de.dhbwstuttgart.syntaxtree.factory.ASTFactory;
 import de.dhbwstuttgart.syntaxtree.factory.NameGenerator;
 import de.dhbwstuttgart.syntaxtree.type.GenericRefType;
-import de.dhbwstuttgart.syntaxtree.type.RefType;
-import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
-import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
 
-import org.antlr.v4.runtime.Token;
 
-import javax.swing.text.html.Option;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;

src/main/java/de/dhbwstuttgart/typeinference/constraints/Constraint.java

@@ -1,77 +1,159 @@
 package de.dhbwstuttgart.typeinference.constraints;
 
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.ISerialNode;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialUUID;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
 
-import java.util.Collection;
+import java.util.ArrayList;
 import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import javax.annotation.Nullable;
 
-public class Constraint<A> extends HashSet<A> {
+public class Constraint<A extends IConstraintElement> extends HashSet<A> implements ISerializableData {
-	private static final long serialVersionUID = 1L;
+  private static final long serialVersionUID = 1L;
-	private Boolean isInherited = false;//wird beides nur für die Method-Constraints benoetigt
+  private Boolean isInherited = false;//wird beides nur für die Method-Constraints benoetigt
-	private Boolean isImplemented = false;
+  private Boolean isImplemented = false;
-	
+
-	/*
+  /*
-	 * wird verwendet um bei der Codegenerierung die richtige Methoden - Signatur
+   * wird verwendet um bei der Codegenerierung die richtige Methoden - Signatur
-	 * auszuwaehlen 
+   * auszuwaehlen
-	 */
+   */
-	/*private*/ Set<A> methodSignatureConstraint = new HashSet<>();
+  /*private*/ Set<A> methodSignatureConstraint = new HashSet<>();
-	
+
-	private Constraint<A> extendConstraint = null;
+  private Constraint<A> extendConstraint = null;
-	
+
-	public Constraint() {
+  public Constraint() {
-		super();
+    super();
-	}
+  }
-	
+
-	public Constraint(Boolean isInherited, Boolean isImplemented) {
+  public Constraint(Boolean isInherited, Boolean isImplemented) {
-		this.isInherited = isInherited;
+    this.isInherited = isInherited;
-		this.isImplemented = isImplemented;
+    this.isImplemented = isImplemented;
-	}
+  }
-	
+
-	public Constraint(Boolean isInherited, Boolean isImplemented, Constraint<A> extendConstraint, Set<A> methodSignatureConstraint) {
+  public Constraint(Boolean isInherited, Boolean isImplemented, Constraint<A> extendConstraint, Set<A> methodSignatureConstraint) {
-		this.isInherited = isInherited;
+    this.isInherited = isInherited;
-		this.isImplemented = isImplemented;
+    this.isImplemented = isImplemented;
-		this.extendConstraint = extendConstraint;
+    this.extendConstraint = extendConstraint;
-		this.methodSignatureConstraint = methodSignatureConstraint;
+    this.methodSignatureConstraint = methodSignatureConstraint;
-	}
+  }
-	
+
-	public void setIsInherited(Boolean isInherited) {
+  public void setIsInherited(Boolean isInherited) {
-		this.isInherited = isInherited;
+    this.isInherited = isInherited;
-	}
+  }
-	
+
-	public Boolean isInherited() {
+  public Boolean isInherited() {
-		return isInherited;
+    return isInherited;
-	}
+  }
-	
+
-	public Boolean isImplemented() {
+  public Boolean isImplemented() {
-		return isImplemented;
+    return isImplemented;
-	}
+  }
-	
+
-	public Constraint<A> getExtendConstraint() {
+  public Constraint<A> getExtendConstraint() {
-		return extendConstraint;
+    return extendConstraint;
-	}
+  }
-	
+
-	public void setExtendConstraint(Constraint<A> c) {
+  public void setExtendConstraint(Constraint<A> c) {
-		extendConstraint = c;
+    extendConstraint = c;
-	}
+  }
-	
+
-	public Set<A> getmethodSignatureConstraint() {
+  public Set<A> getmethodSignatureConstraint() {
-		return methodSignatureConstraint;
+    return methodSignatureConstraint;
-	}
+  }
-	
+
-	public void setmethodSignatureConstraint(Set<A> c) {
+  public void setmethodSignatureConstraint(Set<A> c) {
-		methodSignatureConstraint = c;
+    methodSignatureConstraint = c;
-	}
+  }
+
+  public String toString() {
+    return super.toString() + "\nisInherited = " + isInherited
+      + " isOveridden = " + isImplemented
+      + " msc[" + methodSignatureConstraint.size() + "] = " + methodSignatureConstraint
+      //" + extendsContraint: "  + (extendConstraint != null ? extendConstraint.toStringBase() : "null" )
+      + "\n";
+  }
+
+  public String toStringBase() {
+    return super.toString();
+  }
+
+  private String serialUUID = null;
+
+  @Override
+  public SerialUUID toSerial(KeyStorage keyStorage) {
+    final String uuid = serialUUID == null ? keyStorage.getIdentifier() : serialUUID;
+    if (serialUUID == null) serialUUID = uuid;
+
+    if (!keyStorage.isAlreadySerialized(uuid)) {
+      SerialMap serialized = new SerialMap();
+      keyStorage.putSerialized(uuid, serialized);
+      serialized.put("isInherited", isInherited);
+      serialized.put("isImplemented", isImplemented);
+      serialized.put("extendedConstraint", extendConstraint == null ? null :
+        extendConstraint.toSerial(keyStorage));
+      Function<A, ISerialNode> pairMapper = pair -> {
+        if (pair instanceof Pair simplePair) return simplePair.toSerial(keyStorage);
+        if (pair instanceof UnifyPair unifyPair) return unifyPair.toSerial(keyStorage);
+        throw new RuntimeException("No serialization is supported for type " + pair.getClass().getName());
+      };
+      serialized.put("methodSignatureConstraint", methodSignatureConstraint == null ? null :
+        SerialList.fromMapped(methodSignatureConstraint, pairMapper));
+      serialized.put("setElements", SerialList.fromMapped(this, pairMapper));
+    }
+
+    // return only the unique key
+    return new SerialUUID(uuid);
+  }
+
+  public static <T extends IConstraintElement> Constraint<T> fromSerial(SerialUUID serialUUID, UnifyContext context, Class<T> target, KeyStorage keyStorage) {
+    String uuid = serialUUID.uuid;
+
+    if (!keyStorage.isAlreadyUnserialized(uuid)) {
+      Constraint<T> constraint = new Constraint<>();
+      // immediately add the object to the context to prevent infinite recursion
+      keyStorage.putUnserialized(uuid, constraint);
+
+      // retrieve the serialized data und start unserializing it
+      SerialMap data = keyStorage.getSerialized(uuid);
+      constraint.isInherited = data.getValue("isInherited").getOf(Boolean.class);
+      constraint.isImplemented = data.getValue("isImplemented").getOf(Boolean.class);
+      constraint.extendConstraint = Optional.ofNullable(data.getUUIDOrNull("extendedConstraint"))
+        .map(v -> Constraint.fromSerial(v, context, target, keyStorage))
+        .orElse(null);
+
+      // to convert the maps back to elements, we sadly have to do some assumptions about the generic types...
+      Function<ISerialNode, T> pairUnmapper = pairData -> {
+        if (target == Pair.class && pairData instanceof SerialMap pairMap) {
+          return (T) Pair.fromSerial(pairMap, context);
+        }
+        if (target == UnifyPair.class && pairData instanceof SerialUUID pairUUID) {
+          return (T) UnifyPair.fromSerial(pairUUID, context, keyStorage);
+        }
+        throw new RuntimeException("No serialization is supported for target type " + target.getName());
+      };
+
+      constraint.methodSignatureConstraint =
+        Optional.ofNullable(data.getListOrNull("methodSignatureConstraint"))
+          .map(l -> l.stream().map(pairUnmapper).collect(Collectors.toSet()))
+          .orElse(null);
+      constraint.addAll(
+        data.getList("setElements")
+          .stream().map(pairUnmapper).toList());
+    }
+
+    return keyStorage.getUnserialized(uuid, Constraint.class);
+  }
 
-	public String toString() {
-		return super.toString() + "\nisInherited = " + isInherited + " isOveridden = " + isImplemented
-				+ methodSignatureConstraint
-				//" + extendsContraint: "  + (extendConstraint != null ? extendConstraint.toStringBase() : "null" ) 
-				+ "\n" ;
-	}
-	
-	public String toStringBase() {
-		return super.toString();
-	}
-	
 }

src/main/java/de/dhbwstuttgart/typeinference/constraints/ConstraintSet.java

@@ -1,63 +1,80 @@
 package de.dhbwstuttgart.typeinference.constraints;
 
 
-import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.typeinference.unify.GuavaSetOperations;
-import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 
+import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
 import java.util.*;
 import java.util.function.BinaryOperator;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
-public class ConstraintSet<A> {
+public class ConstraintSet<A extends IConstraintElement> implements ISerializableData {
-    Constraint<A> undConstraints = new Constraint<>();
+  Constraint<A> undConstraints = new Constraint<>();
-    List<Set<Constraint<A>>> oderConstraints = new ArrayList<>();
+  List<Set<Constraint<A>>> oderConstraints = new ArrayList<>();
 
-    public void addUndConstraint(A p){
+  public void addUndConstraint(A p) {
-        undConstraints.add(p);
+    undConstraints.add(p);
-    }
+  }
 
-    public void addOderConstraint(Set<Constraint<A>> methodConstraints) {
+  public void addOderConstraint(Set<Constraint<A>> methodConstraints) {
-        oderConstraints.add(methodConstraints);
+    oderConstraints.add(methodConstraints);
-    }
+  }
 
-    public void addAllUndConstraint(Constraint<A> allUndConstraints){
+  public void addAllUndConstraint(Constraint<A> allUndConstraints) {
-        undConstraints.addAll(allUndConstraints);
+    undConstraints.addAll(allUndConstraints);
-    }
+  }
-    
-    public void addAllOderConstraint(List<Set<Constraint<A>>> allOderConstraints){
-        this.oderConstraints.addAll(allOderConstraints);
-    }
-    
-    public void addAll(ConstraintSet constraints) {
-        this.addAllUndConstraint(constraints.undConstraints);
-        this.addAllOderConstraint(constraints.oderConstraints);
-    }
 
-    @Override
+  public void addAllOderConstraint(List<Set<Constraint<A>>> allOderConstraints) {
-    public String toString(){
+    this.oderConstraints.addAll(allOderConstraints);
-    	BinaryOperator<String> b = (x,y) -> x+y;
+  }
-        return "\nUND:" + this.undConstraints.toString() + "\n" + 
-    		   "ODER:" + this.oderConstraints.stream().reduce("", (x,y) -> x.toString()+ "\n"  +y, b);
-        		//cartesianProduct().toString();
-    }
 
-    public Set<List<Constraint<A>>> cartesianProduct(){
+  public void addAll(ConstraintSet constraints) {
-        Set<Constraint<A>> toAdd = new HashSet<>();
+    this.addAllUndConstraint(constraints.undConstraints);
-        toAdd.add(undConstraints);
+    this.addAllOderConstraint(constraints.oderConstraints);
-        List<Set<Constraint<A>>> allConstraints = new ArrayList<>();
+  }
-        allConstraints.add(toAdd);
-        allConstraints.addAll(oderConstraints);
-        return new GuavaSetOperations().cartesianProduct(allConstraints);
-    }
 
-    public <B> ConstraintSet<B> map(Function<? super A, ? extends B> o) {
+  @Override
-    	Hashtable<Constraint<A>,Constraint<B>> CSA2CSB = new Hashtable<>();
+  public String toString() {
-        ConstraintSet<B> ret = new ConstraintSet<>();
+    BinaryOperator<String> b = (x, y) -> x + y;
-        ret.undConstraints = undConstraints.stream().map(o).collect(Collectors.toCollection(Constraint<B>::new));
+    return "\nUND:\n" + this.undConstraints.toString() +
-        List<Set<Constraint<B>>> newOder = new ArrayList<>();
+      "ODER:" + this.oderConstraints.stream().reduce("", (x, y) -> x + "\n\t" + y, b) +
+      "\n";
+    //cartesianProduct().toString();
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (!(obj instanceof ConstraintSet<?> other)) return false;
+    return Objects.equals(undConstraints, other.undConstraints)
+      && Objects.equals(oderConstraints, other.oderConstraints);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(undConstraints, oderConstraints);
+  }
+
+  public Set<List<Constraint<A>>> cartesianProduct() {
+    Set<Constraint<A>> toAdd = new HashSet<>();
+    toAdd.add(undConstraints);
+    List<Set<Constraint<A>>> allConstraints = new ArrayList<>();
+    allConstraints.add(toAdd);
+    allConstraints.addAll(oderConstraints);
+    return new GuavaSetOperations().cartesianProduct(allConstraints);
+  }
+
+  public <B extends IConstraintElement> ConstraintSet<B> map(Function<? super A, ? extends B> o) {
+    Hashtable<Constraint<A>, Constraint<B>> CSA2CSB = new Hashtable<>();
+    ConstraintSet<B> ret = new ConstraintSet<>();
+    ret.undConstraints = undConstraints.stream().map(o).collect(Collectors.toCollection(Constraint<B>::new));
+    List<Set<Constraint<B>>> newOder = new ArrayList<>();
         /*
         for(Set<Constraint<A>> oderConstraint : oderConstraints){
         	oderConstraint.forEach(as -> {
@@ -68,25 +85,25 @@ public class ConstraintSet<A> {
             	CSA2CSB.put(as, newConst);} );
         }
         */
-        
+
-        for(Set<Constraint<A>> oderConstraint : oderConstraints){
+    for (Set<Constraint<A>> oderConstraint : oderConstraints) {
-            newOder.add(
+      newOder.add(
-                    oderConstraint.stream().map((Constraint<A> as) -> {
+        oderConstraint.stream().map((Constraint<A> as) -> {
-                    	
+
-                    	Constraint<B> newConst = as.stream()
+          Constraint<B> newConst = as.stream()
-                    			.map(o)
+            .map(o)
-                    			.collect(Collectors.toCollection((
+            .collect(Collectors.toCollection((
-                    					() -> new Constraint<B> (as.isInherited(),
+              () -> new Constraint<B>(as.isInherited(),
-                    											 as.isImplemented(),
+                as.isImplemented(),
-                    											 (as.getExtendConstraint() != null)
+                (as.getExtendConstraint() != null)
-                    											     ? as.getExtendConstraint().stream().map(o).collect(Collectors.toCollection(Constraint::new))
+                  ? as.getExtendConstraint().stream().map(o).collect(Collectors.toCollection(Constraint::new))
-                    											     : null,
+                  : null,
-                    							                 as.getmethodSignatureConstraint().stream().map(o).collect(Collectors.toCollection(HashSet::new)))) 
+                as.getmethodSignatureConstraint().stream().map(o).collect(Collectors.toCollection(HashSet::new))))
-                    			));                    							
+            ));
-                    	
+
-                    	//CSA2CSB.put(as, newConst);
+          //CSA2CSB.put(as, newConst);
-                    	
+
-                    	return newConst;
+          return newConst;
                     	
                     	/*
                     	Constraint<B> bs = CSA2CSB.get(as);
@@ -95,36 +112,60 @@ public class ConstraintSet<A> {
                     	}
                     	return bs;
                     	*/
-                    }).collect(Collectors.toSet())
+        }).collect(Collectors.toSet())
-            );
+      );
-        }
-        
-        ret.oderConstraints = newOder;
-        return ret;
     }
-    
+
-    public void forEach (Consumer<? super A> c) {
+    ret.oderConstraints = newOder;
-        undConstraints.stream().forEach(c);
+    return ret;
-        for(Set<Constraint<A>> oderConstraint : oderConstraints){
+  }
-            oderConstraint.parallelStream().forEach((Constraint<A> as) ->
+
-                            as.stream().forEach(c));
+  public void forEach(Consumer<? super A> c) {
-        }
+    undConstraints.stream().forEach(c);
+    for (Set<Constraint<A>> oderConstraint : oderConstraints) {
+      oderConstraint.parallelStream().forEach((Constraint<A> as) ->
+        as.stream().forEach(c));
     }
-    
+  }
-    public Set<A> getAll () {
+
-    	Set<A> ret = new HashSet<>();
+  public Set<A> getAll() {
-        ret.addAll(undConstraints);
+    Set<A> ret = new HashSet<>(undConstraints);
-        for(Set<Constraint<A>> oderConstraint : oderConstraints){
+    for (Set<Constraint<A>> oderConstraint : oderConstraints) {
-            oderConstraint.parallelStream().forEach((Constraint<A> as) -> ret.addAll(as));
+      oderConstraint.parallelStream().forEach(ret::addAll);
-        }
-        return ret;
-    }
-    
-    public List<Set<Constraint<A>>> getOderConstraints() {
-    	return oderConstraints;
-    }
-    
-    public Set<A> getUndConstraints() {
-    	return undConstraints;
     }
+    return ret;
+  }
+
+  public List<Set<Constraint<A>>> getOderConstraints() {
+    return oderConstraints;
+  }
+
+  public Set<A> getUndConstraints() {
+    return undConstraints;
+  }
+
+  @Override
+  public SerialMap toSerial(KeyStorage keyStorage) {
+    SerialMap serialized = new SerialMap();
+    serialized.put("undConstraints", undConstraints.toSerial(keyStorage));
+    serialized.put("oderConstraints", SerialList.fromMapped(oderConstraints, oderConstraintSet ->
+      SerialList.fromMapped(oderConstraintSet, oderConstraint ->
+        oderConstraint.toSerial(keyStorage))
+    ));
+    return serialized;
+  }
+
+  public static <T extends IConstraintElement> ConstraintSet<T> fromSerial(SerialMap data, UnifyContext context, Class<T> target, KeyStorage keyStorage) {
+    ConstraintSet<T> constraintSet = new ConstraintSet<>();
+
+    constraintSet.undConstraints = Constraint.fromSerial(data.getUUID("undConstraints"), context, target, keyStorage);
+    constraintSet.oderConstraints = data.getList("oderConstraints").assertListOfLists().stream()
+      .map(oderConstraintSetData -> oderConstraintSetData.assertListOfUUIDs().stream()
+        .map(oderConstraintData -> Constraint.fromSerial(oderConstraintData, context, target, keyStorage))
+        .collect(Collectors.toSet())
+      ).toList();
+
+    return constraintSet;
+  }
+
 }

src/main/java/de/dhbwstuttgart/typeinference/constraints/IConstraintElement.java

@@ -0,0 +1,4 @@
+package de.dhbwstuttgart.typeinference.constraints;
+
+public interface IConstraintElement {
+}

src/main/java/de/dhbwstuttgart/typeinference/constraints/Pair.java

@@ -1,72 +1,70 @@
 package de.dhbwstuttgart.typeinference.constraints;
+
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
 
-import de.dhbwstuttgart.parser.NullToken;
 import de.dhbwstuttgart.parser.SourceLoc;
 import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
 import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
 import de.dhbwstuttgart.typeinference.unify.model.PairOperator;
-import org.antlr.v4.runtime.Token;
 
 
-public class Pair implements Serializable
+public class Pair implements Serializable, IConstraintElement, ISerializableData {
-{
+  public final RefTypeOrTPHOrWildcardOrGeneric TA1;
-    public final RefTypeOrTPHOrWildcardOrGeneric TA1;
+  public final RefTypeOrTPHOrWildcardOrGeneric TA2;
-    public final RefTypeOrTPHOrWildcardOrGeneric TA2;
 
-    private SourceLoc location;
+  private SourceLoc location;
 
-    private PairOperator eOperator = PairOperator.SMALLER;
+  private PairOperator eOperator = PairOperator.SMALLER;
-    private Boolean noUnification = false;
+  private Boolean noUnification = false;
-    
 
-    private Pair(RefTypeOrTPHOrWildcardOrGeneric TA1, RefTypeOrTPHOrWildcardOrGeneric TA2 )
-    {
-        this.TA1 = TA1;
-        this.TA2 = TA2;
-        if(TA1 == null || TA2 == null)
-            throw new NullPointerException();
-        eOperator = PairOperator.SMALLER;
-    }
 
-    public Pair(RefTypeOrTPHOrWildcardOrGeneric TA1, RefTypeOrTPHOrWildcardOrGeneric TA2, PairOperator eOp)
+  private Pair(RefTypeOrTPHOrWildcardOrGeneric TA1, RefTypeOrTPHOrWildcardOrGeneric TA2) {
-    {
+    this.TA1 = TA1;
-        // Konstruktor
+    this.TA2 = TA2;
-        this(TA1,TA2);
+    if (TA1 == null || TA2 == null)
-        this.eOperator = eOp;
+      throw new NullPointerException();
-    }
+    eOperator = PairOperator.SMALLER;
+  }
 
-    public Pair(RefTypeOrTPHOrWildcardOrGeneric TA1, RefTypeOrTPHOrWildcardOrGeneric TA2, PairOperator e0p, SourceLoc location) {
+  public Pair(RefTypeOrTPHOrWildcardOrGeneric TA1, RefTypeOrTPHOrWildcardOrGeneric TA2, PairOperator eOp) {
-        this(TA1, TA2, e0p);
+    // Konstruktor
-        this.location = location;
+    this(TA1, TA2);
-    }
+    this.eOperator = eOp;
-    
+  }
-    public Pair(RefTypeOrTPHOrWildcardOrGeneric TA1, RefTypeOrTPHOrWildcardOrGeneric TA2, PairOperator eOp, Boolean noUnification)
-    {
-        // Konstruktor
-        this(TA1,TA2);
-        this.eOperator = eOp;
-        this.noUnification = noUnification;
-    }
 
-    public SourceLoc getLocation() {
+  public Pair(RefTypeOrTPHOrWildcardOrGeneric TA1, RefTypeOrTPHOrWildcardOrGeneric TA2, PairOperator e0p, SourceLoc location) {
-        return this.location;
+    this(TA1, TA2, e0p);
-    }
+    this.location = location;
-    
+  }
-    public String toString()
+
-    {
+  public Pair(RefTypeOrTPHOrWildcardOrGeneric TA1, RefTypeOrTPHOrWildcardOrGeneric TA2, PairOperator eOp, Boolean noUnification) {
-        // otth: Gibt ein Paar als String aus --> zum Debuggen und Vergleichen
+    // Konstruktor
-        String strElement1 = "NULL";
+    this(TA1, TA2);
-        String strElement2 = "NULL";
+    this.eOperator = eOp;
-        String Operator = "<.";
+    this.noUnification = noUnification;
-        
+  }
-        if( TA1 != null )
+
-             strElement1 = TA1.toString();
+  public SourceLoc getLocation() {
-    
+    return this.location;
-        if( TA2 != null )
+  }
-           strElement2 = TA2.toString();
+
+  public String toString() {
+    // otth: Gibt ein Paar als String aus --> zum Debuggen und Vergleichen
+    String strElement1 = "NULL";
+    String strElement2 = "NULL";
+    String Operator = "<.";
+
+    if (TA1 != null)
+      strElement1 = TA1.toString();
+
+    if (TA2 != null)
+      strElement2 = TA2.toString();
         
        /* PL ausskommentiert 2018-05-24
         if(OperatorEqual())
@@ -76,80 +74,104 @@ public class Pair implements Serializable
         if(OperatorSmallerExtends())
         	Operator = "<?";
         	*/
-        
-        return "\n(" + strElement1 + " " + eOperator.toString() + " " + strElement2 + ")";
-        
-       /*- Equals: " + bEqual*/
-    }
 
-    /**
+    return "\n(P: " + strElement1 + " " + eOperator.toString() + " " + strElement2 + ")";
-     * <br/>Author: J�rg B�uerle
-     * @param obj
-     * @return
-     */
-    public boolean equals(Object obj)
-    {
-        boolean ret = true;
-        ret &= (obj instanceof Pair);
-        if(!ret)return ret;
-        ret &= ((Pair)obj).TA1.equals(this.TA1);
-        ret &= ((Pair)obj).TA2.equals(this.TA2);
-        return ret;
-    }
 
-    /**
+    /*- Equals: " + bEqual*/
-	* Author: Arne Lüdtke<br/>
+  }
-	* Abfrage, ob Operator vom Typ Equal ist.
-	*/
-    public boolean OperatorEqual()
-    {
-    	return eOperator == PairOperator.EQUALSDOT;
-    }
-    
-    /**
-	* Author: Arne Lüdtke<br/>
-	* Abfrage, ob Operator vom Typ Smaller ist.
-	*/
-    public boolean OperatorSmaller()
-    {
-    	return eOperator == PairOperator.SMALLER;
-    }
-    
-    /**
-	* Author: Arne Lüdtke<br/>
-	* Abfrage, ob Operator vom Typ SmallerExtends ist.
-	*/
-    public boolean OperatorSmallerExtends()
-    {
-    	return eOperator == PairOperator.SMALLERDOTWC;
-    }
-    
-    /**
-	* Author: Arne Lüdtke<br/>
-	* Gibt den Operator zurück.
-	*/
-    public PairOperator GetOperator()
-    {
-    	return eOperator;
-    }
 
-    public boolean OperatorSmallerDot() {
+  /**
-        return eOperator == PairOperator.SMALLERDOT;
+   * <br/>Author: J�rg B�uerle
-    }
+   *
-    
+   * @param obj
-    
+   * @return
-    static public Map<String, TypePlaceholder> generateTPHMap(ConstraintSet<Pair> constraints) {
+   */
-        HashMap<String, TypePlaceholder> ret = new HashMap<>();
+  public boolean equals(Object obj) {
-        constraints.map((Pair p) -> {
+    return (
-            if (p.TA1 instanceof TypePlaceholder) {
+      (obj instanceof Pair pairObj) &&
-                ret.put(((TypePlaceholder) p.TA1).getName(), (TypePlaceholder) p.TA1);
+        pairObj.TA1.equals(this.TA1) &&
-            }
+        pairObj.TA2.equals(this.TA2)
-            if (p.TA2 instanceof TypePlaceholder) {
+    );
-                ret.put(((TypePlaceholder) p.TA2).getName(), (TypePlaceholder) p.TA2);
+  }
-            }
+
-            return null;
+  /**
-        });
+   * Author: Arne Lüdtke<br/>
-        return ret;
+   * Abfrage, ob Operator vom Typ Equal ist.
-    }
+   */
+  public boolean OperatorEqual() {
+    return eOperator == PairOperator.EQUALSDOT;
+  }
+
+  /**
+   * Author: Arne Lüdtke<br/>
+   * Abfrage, ob Operator vom Typ Smaller ist.
+   */
+  public boolean OperatorSmaller() {
+    return eOperator == PairOperator.SMALLER;
+  }
+
+  /**
+   * Author: Arne Lüdtke<br/>
+   * Abfrage, ob Operator vom Typ SmallerExtends ist.
+   */
+  public boolean OperatorSmallerExtends() {
+    return eOperator == PairOperator.SMALLERDOTWC;
+  }
+
+  /**
+   * Author: Arne Lüdtke<br/>
+   * Gibt den Operator zurück.
+   */
+  public PairOperator GetOperator() {
+    return eOperator;
+  }
+
+  public boolean OperatorSmallerDot() {
+    return eOperator == PairOperator.SMALLERDOT;
+  }
+
+
+  static public Map<String, TypePlaceholder> generateTPHMap(ConstraintSet<Pair> constraints) {
+    HashMap<String, TypePlaceholder> ret = new HashMap<>();
+    constraints.map((Pair p) -> {
+      if (p.TA1 instanceof TypePlaceholder) {
+        ret.put(((TypePlaceholder) p.TA1).getName(), (TypePlaceholder) p.TA1);
+      }
+      if (p.TA2 instanceof TypePlaceholder) {
+        ret.put(((TypePlaceholder) p.TA2).getName(), (TypePlaceholder) p.TA2);
+      }
+      return null;
+    });
+    return ret;
+  }
+
+  @Override
+  public SerialMap toSerial(KeyStorage keyStorage) {
+    // because toString() will output TA1 and TA2 recursively, we can ignore potential infinite recursion here too
+    SerialMap serialized = new SerialMap();
+    serialized.put("ta1", this.TA1.toSerial(keyStorage));
+    serialized.put("ta2", this.TA2.toSerial(keyStorage));
+    serialized.put("op", this.eOperator.toString());
+    serialized.put("noUnification", this.noUnification ? 1 : 0);
+    serialized.put("location", this.location == null ? null : this.location.toSerial(keyStorage));
+    return serialized;
+  }
+
+  public static Pair fromSerial(SerialMap data, UnifyContext context) {
+    String op = data.getValue("op").getOf(String.class);
+    SerialMap ta1 = data.getMap("ta1");
+    SerialMap ta2 = data.getMap("ta2");
+    Boolean noUnification = data.getValue("noUnification").getOf(Integer.class) == 1;
+    SerialMap location = data.getMapOrNull("location");
+
+    var pair = new Pair(
+      RefTypeOrTPHOrWildcardOrGeneric.fromSerial(ta1, context),
+      RefTypeOrTPHOrWildcardOrGeneric.fromSerial(ta2, context),
+      PairOperator.fromString(op),
+      noUnification
+    );
+    if (location != null) pair.location = SourceLoc.fromSerial(location);
+    return pair;
+  }
 }
 // ino.end

src/main/java/de/dhbwstuttgart/typeinference/result/PairNoResult.java

@@ -1,15 +1,19 @@
 package de.dhbwstuttgart.typeinference.result;
 
 import de.dhbwstuttgart.exceptions.NotImplementedException;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
-import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 
 /**
  * enthaelt alle Paare, die in einem Ergebnis nicht vorkommen koennen
  * sie sind noetig fuer origPairs in PairTPHsmallerTPH, da hier auch
  * Paare vorkommen koennen die keine Result sind (z.B. bei FunN$$)
  */
-public class PairNoResult extends ResultPair<RefTypeOrTPHOrWildcardOrGeneric, RefTypeOrTPHOrWildcardOrGeneric>{
+public class PairNoResult extends ResultPair<RefTypeOrTPHOrWildcardOrGeneric, RefTypeOrTPHOrWildcardOrGeneric>
+implements ISerializableData {
     //public final TypePlaceholder left;
     //public final TypePlaceholder right;
     
@@ -17,7 +21,7 @@ public class PairNoResult extends ResultPair<RefTypeOrTPHOrWildcardOrGeneric, Re
      * urspruengliches Paar aus diesem dieses Resultpair erzeugt wurde
      * wichtig fuer generated Generics
      */
-    ResultPair origPair;
+    ResultPair<?,?> origPair;
 
     public PairNoResult(RefTypeOrTPHOrWildcardOrGeneric left, RefTypeOrTPHOrWildcardOrGeneric right){
         super(left, right);
@@ -29,4 +33,24 @@ public class PairNoResult extends ResultPair<RefTypeOrTPHOrWildcardOrGeneric, Re
     	throw new NotImplementedException();
         //visitor.visit(this);
     }
+
+    @Override
+    public SerialMap toSerial(KeyStorage keyStorage) {
+        SerialMap serialized = new SerialMap();
+        serialized.put("left", this.getLeft().toSerial(keyStorage));
+        serialized.put("right", this.getRight().toSerial(keyStorage));
+        // create the wrapper and put this as the object
+        var serializedWrapper = super.toSerial(keyStorage);
+        serializedWrapper.put("object", serialized);
+        return serializedWrapper;
+    }
+
+    public static PairNoResult fromSerial2(SerialMap data, UnifyContext context) {
+        SerialMap left = data.getMap("left");
+        SerialMap right = data.getMap("right");
+        return new PairNoResult(
+          RefTypeOrTPHOrWildcardOrGeneric.fromSerial(left, context),
+          RefTypeOrTPHOrWildcardOrGeneric.fromSerial(right, context)
+        );
+    }
 }

src/main/java/de/dhbwstuttgart/typeinference/result/PairTPHEqualTPH.java

@@ -1,9 +1,13 @@
 package de.dhbwstuttgart.typeinference.result;
 
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
 import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 
-public class PairTPHEqualTPH extends ResultPair<TypePlaceholder, TypePlaceholder> {
+public class PairTPHEqualTPH extends ResultPair<TypePlaceholder, TypePlaceholder> implements ISerializableData {
     public PairTPHEqualTPH(TypePlaceholder tl, TypePlaceholder tr) {
         super(tl, tr);
     }
@@ -12,4 +16,24 @@ public class PairTPHEqualTPH extends ResultPair<TypePlaceholder, TypePlaceholder
     public void accept(ResultPairVisitor visitor) {
         visitor.visit(this);
     }
+
+    @Override
+    public SerialMap toSerial(KeyStorage keyStorage) {
+        SerialMap serialized = new SerialMap();
+        serialized.put("left", this.getLeft().toSerial(keyStorage));
+        serialized.put("right", this.getRight().toSerial(keyStorage));
+        // create the wrapper and put this as the object
+        var serializedWrapper = super.toSerial(keyStorage);
+        serializedWrapper.put("object", serialized);
+        return serializedWrapper;
+    }
+
+    public static PairTPHEqualTPH fromSerial2(SerialMap data, UnifyContext context) {
+        SerialMap left = data.getMap("left");
+        SerialMap right = data.getMap("right");
+        return new PairTPHEqualTPH(
+          (TypePlaceholder) RefTypeOrTPHOrWildcardOrGeneric.fromSerial(left, context),
+          (TypePlaceholder) RefTypeOrTPHOrWildcardOrGeneric.fromSerial(right, context)
+        );
+    }
 }

src/main/java/de/dhbwstuttgart/typeinference/result/PairTPHequalRefTypeOrWildcardType.java

@@ -1,13 +1,17 @@
 package de.dhbwstuttgart.typeinference.result;
 
-import de.dhbwstuttgart.syntaxtree.type.RefType;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
 import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 
 /**
  * Steht für A =. RefType
  */
-public class PairTPHequalRefTypeOrWildcardType extends ResultPair{
+public class PairTPHequalRefTypeOrWildcardType extends ResultPair<TypePlaceholder, RefTypeOrTPHOrWildcardOrGeneric>
+implements ISerializableData {
     public final TypePlaceholder left;
     public final RefTypeOrTPHOrWildcardOrGeneric right;
 
@@ -26,4 +30,24 @@ public class PairTPHequalRefTypeOrWildcardType extends ResultPair{
     public String toString() {
     	return "(" + left.toString() + " = " + right.toString() + ")";
     }
+
+    @Override
+    public SerialMap toSerial(KeyStorage keyStorage) {
+        SerialMap serialized = new SerialMap();
+        serialized.put("left", this.getLeft().toSerial(keyStorage));
+        serialized.put("right", this.getRight().toSerial(keyStorage));
+        // create the wrapper and put this as the object
+        var serializedWrapper = super.toSerial(keyStorage);
+        serializedWrapper.put("object", serialized);
+        return serializedWrapper;
+    }
+
+    public static PairTPHequalRefTypeOrWildcardType fromSerial2(SerialMap data, UnifyContext context) {
+        SerialMap left = data.getMap("left");
+        SerialMap right = data.getMap("right");
+        return new PairTPHequalRefTypeOrWildcardType(
+          (TypePlaceholder)RefTypeOrTPHOrWildcardOrGeneric.fromSerial(left, context),
+          RefTypeOrTPHOrWildcardOrGeneric.fromSerial(right, context)
+        );
+    }
 }

src/main/java/de/dhbwstuttgart/typeinference/result/PairTPHsmallerTPH.java

@@ -1,12 +1,17 @@
 package de.dhbwstuttgart.typeinference.result;
 
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
 import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
 import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 
 /**
  * Steht für: A <. B
  */
-public class PairTPHsmallerTPH extends ResultPair{
+public class PairTPHsmallerTPH extends ResultPair<TypePlaceholder,TypePlaceholder>
+  implements ISerializableData {
     public final TypePlaceholder left;
     public final TypePlaceholder right;
     
@@ -14,7 +19,7 @@ public class PairTPHsmallerTPH extends ResultPair{
      * urspruengliches Paar aus diesem dieses Resultpair erzeugt wurde
      * wichtig fuer generated Generics
      */
-    ResultPair origPair;
+    ResultPair<?,?> origPair;
 
     public PairTPHsmallerTPH(TypePlaceholder left, TypePlaceholder right){
         super(left, right);
@@ -22,7 +27,7 @@ public class PairTPHsmallerTPH extends ResultPair{
         this.right = right;
     }
 
-    public PairTPHsmallerTPH(TypePlaceholder left, TypePlaceholder right, ResultPair origPair){
+    public PairTPHsmallerTPH(TypePlaceholder left, TypePlaceholder right, ResultPair<?,?> origPair){
     	this(left, right);
     	this.origPair = origPair;
     }
@@ -36,4 +41,24 @@ public class PairTPHsmallerTPH extends ResultPair{
     public String toString() {
     	return "(" + left.toString() + " < " + right.toString() + ")";
     }
+
+    @Override
+    public SerialMap toSerial(KeyStorage keyStorage) {
+        SerialMap serialized = new SerialMap();
+        serialized.put("left", this.getLeft().toSerial(keyStorage));
+        serialized.put("right", this.getRight().toSerial(keyStorage));
+        // create the wrapper and put this as the object
+        var serializedWrapper = super.toSerial(keyStorage);
+        serializedWrapper.put("object", serialized);
+        return serializedWrapper;
+    }
+
+    public static PairTPHsmallerTPH fromSerial2(SerialMap data, UnifyContext context) {
+        SerialMap left = data.getMap("left");
+        SerialMap right = data.getMap("right");
+        return new PairTPHsmallerTPH(
+          (TypePlaceholder) RefTypeOrTPHOrWildcardOrGeneric.fromSerial(left, context),
+          (TypePlaceholder) RefTypeOrTPHOrWildcardOrGeneric.fromSerial(right, context)
+        );
+    }
 }

src/main/java/de/dhbwstuttgart/typeinference/result/ResultPair.java

@@ -1,11 +1,17 @@
 package de.dhbwstuttgart.typeinference.result;
 
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialValue;
 import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 
 /**
  * Paare, welche das Unifikationsergebnis darstellen
  */
-public abstract class ResultPair<A extends RefTypeOrTPHOrWildcardOrGeneric,B extends RefTypeOrTPHOrWildcardOrGeneric> {
+public abstract class ResultPair<A extends RefTypeOrTPHOrWildcardOrGeneric,B extends RefTypeOrTPHOrWildcardOrGeneric>
+implements ISerializableData {
     private final A left;
     private final B right;
 
@@ -58,5 +64,35 @@ public abstract class ResultPair<A extends RefTypeOrTPHOrWildcardOrGeneric,B ext
 			return false;
 		return true;
 	}
-   
+
+
+	@Override
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		String type = switch (this) {
+      case PairNoResult _ -> "pnr";
+      case PairTPHEqualTPH _ -> "ptet";
+      case PairTPHsmallerTPH _ -> "ptst";
+      case PairTPHequalRefTypeOrWildcardType _ -> "ptertwt";
+      default -> throw new RuntimeException("No type defined for ResultPair of class " + this.getClass().getName());
+    };
+    serialized.put("type", type);
+		// we only insert null for the object and expect the child classes to call this and override the value with themselves
+		serialized.put("object", SerialValue.NULL);
+		return serialized;
+	}
+
+	public static <A extends RefTypeOrTPHOrWildcardOrGeneric,B extends RefTypeOrTPHOrWildcardOrGeneric> ResultPair<A,B>
+	fromSerial(SerialMap data, UnifyContext context) {
+		String type = data.getValue("type").getOf(String.class);
+		SerialMap object = data.getMap("object");
+
+    return switch (type) {
+      case "pnr" -> (ResultPair) PairNoResult.fromSerial2(object, context);
+      case "ptet" -> (ResultPair) PairTPHEqualTPH.fromSerial2(object, context);
+      case "ptst" -> (ResultPair) PairTPHsmallerTPH.fromSerial2(object, context);
+      case "ptertwt" -> (ResultPair) PairTPHequalRefTypeOrWildcardType.fromSerial2(object, context);
+      default -> throw new RuntimeException("Could not unserialize class of unhandled type " + type);
+    };
+	}
 }

src/main/java/de/dhbwstuttgart/typeinference/result/ResultSet.java

@@ -1,5 +1,13 @@
 package de.dhbwstuttgart.typeinference.result;
 
+import com.google.common.collect.Ordering;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -10,148 +18,177 @@ import de.dhbwstuttgart.syntaxtree.type.RefType;
 import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
 import de.dhbwstuttgart.syntaxtree.type.SuperWildcardType;
 import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
+import java.util.stream.Collectors;
 
 @SuppressWarnings("rawtypes")
-public class ResultSet {
+public class ResultSet implements ISerializableData {
 
-    public final Set<ResultPair> results;
+  public final Set<ResultPair> results;
-    public Set<ResultPair<TypePlaceholder, TypePlaceholder>> genIns;
+  public Set<ResultPair<TypePlaceholder, TypePlaceholder>> genIns;
 
-    public ResultSet(Set<ResultPair> set){
+  public ResultSet(Set<ResultPair> set) {
-        this.results = set;
+    this.results = set;
-        this.genIns = new HashSet<>();
+    this.genIns = new HashSet<>();
-        results.forEach(x -> { if (x instanceof PairTPHsmallerTPH) { this.genIns.add(x);}} );
+    results.forEach(x -> {
-    }
+      if (x instanceof PairTPHsmallerTPH) {
-    
+        this.genIns.add(x);
-    public boolean contains(ResultPair toCheck) {
+      }
-    	return this.results.contains(toCheck);
+    });
-    }
+  }
-    
+
-    public void remove(ResultPair toCheck) {
+  public boolean contains(ResultPair toCheck) {
-    	results.remove(toCheck);
+    return this.results.contains(toCheck);
+  }
+
+  public void remove(ResultPair toCheck) {
+    results.remove(toCheck);
+  }
+
+  public ResolvedType resolveType(RefTypeOrTPHOrWildcardOrGeneric type) {
+    if (type instanceof TypePlaceholder)
+      return new Resolver(this).resolve((TypePlaceholder) type);
+    if (type instanceof GenericRefType) return new ResolvedType(type, new HashSet<>());
+    if (type instanceof RefType) {
+      RelatedTypeWalker related = new RelatedTypeWalker(null, this);
+      type.accept(related);
+      return new ResolvedType(type, related.relatedTPHs);
+    } else {
+      throw new NotImplementedException();
+      //return new ResolvedType(type,new HashSet<>());
     }
+  }
 
-    public ResolvedType resolveType(RefTypeOrTPHOrWildcardOrGeneric type) {
+  public String toString() {
-        if(type instanceof TypePlaceholder)
+    var results = new ArrayList<>(this.results);
-            return new Resolver(this).resolve((TypePlaceholder)type);
+    results.sort(
-        if(type instanceof GenericRefType)return new ResolvedType(type, new HashSet<>());
+      Comparator
-        if(type instanceof RefType) {
+        .comparingInt((ResultPair o) -> o.getLeft().toString().length())
-            RelatedTypeWalker related = new RelatedTypeWalker(null, this);
+        .thenComparing(o -> o.getLeft().toString())
-            type.accept(related);
+        .thenComparingInt(o -> o.getRight().toString().length())
-            return new ResolvedType(type, related.relatedTPHs);
+        .thenComparing(o -> o.getRight().toString())
-        } else {
+    );
-            throw new NotImplementedException();
+    return results.toString();
-            //return new ResolvedType(type,new HashSet<>());
+  }
-        }
+
+  @Override
+  public boolean equals(Object o) {
+    if (o instanceof ResultSet other) {
+      // sort both result lists
+      var thisElements = new ArrayList<>(this.results);
+      thisElements.sort(Ordering.usingToString());
+      var otherElements = new ArrayList<>(other.results);
+      otherElements.sort(Ordering.usingToString());
+
+      return thisElements.equals(otherElements);
+    } else {
+      return false;
     }
+  }
 
-    public String toString() {
+  @Override
-    	return results.toString();
+  public int hashCode() {
-    }
+    return results.hashCode();
+  }
 
-	@Override
+  @Override
-	public boolean equals(Object o) {
+  public SerialMap toSerial(KeyStorage keyStorage) {
-		if (o instanceof ResultSet) {
+    SerialMap serialized = new SerialMap();;
-			ResultSet other = (ResultSet)o;
+    serialized.put("results", SerialList.fromMapped(results, result -> result.toSerial(keyStorage)));
-			return this.results.equals(other.results);
+    return serialized;
-		} else {
+  }
-			return false;
-		}
-	}
 
-	@Override
+  public static ResultSet fromSerial(SerialMap data, UnifyContext context) {
-	public int hashCode() {
+    var resultsData = data.getList("results").assertListOfMaps();
-		return results.hashCode();
+    return new ResultSet(resultsData.stream().map(resultData -> ResultPair.fromSerial(resultData, context)).collect(Collectors.toSet()));
-	}
+  }
 }
 
 class Resolver implements ResultSetVisitor {
-    private final ResultSet result;
+  private final ResultSet result;
-    private TypePlaceholder toResolve;
+  private TypePlaceholder toResolve;
-    private RefTypeOrTPHOrWildcardOrGeneric resolved;
+  private RefTypeOrTPHOrWildcardOrGeneric resolved;
-    private final Set<GenericInsertPair> additionalTPHs = new HashSet<>();
+  private final Set<GenericInsertPair> additionalTPHs = new HashSet<>();
-    private ResultPair<?,?> currentPair;
+  private ResultPair<?, ?> currentPair;
 
-    public Resolver(ResultSet resultPairs){
+  public Resolver(ResultSet resultPairs) {
-        this.result = resultPairs;
+    this.result = resultPairs;
+  }
+
+  public ResolvedType resolve(TypePlaceholder tph) {
+    toResolve = tph;
+    resolved = null;
+    System.out.println(tph.toString());
+    for (ResultPair<?, ?> resultPair : result.results) {
+      if (resultPair instanceof PairTPHEqualTPH && ((PairTPHEqualTPH) resultPair).getLeft().equals(toResolve)) {
+        currentPair = resultPair;
+        return resolve(((PairTPHEqualTPH) resultPair).getRight());
+      }
+    }
+    for (ResultPair<?, ?> resultPair : result.results) {
+      currentPair = resultPair;
+      resultPair.accept(this);
+    }
+    if (resolved == null) {//TPH kommt nicht im Result vor:
+      resolved = tph;
     }
 
-    public ResolvedType resolve(TypePlaceholder tph){
+    ResolvedType result = new ResolvedType(resolved, additionalTPHs);//resolved;
-        toResolve = tph;
+    result.setResultPair(currentPair);
-        resolved = null;
+    return result;
-        System.out.println(tph.toString());
+  }
-        for(ResultPair<?,?> resultPair : result.results) {
-            if(resultPair instanceof PairTPHEqualTPH && ((PairTPHEqualTPH) resultPair).getLeft().equals(toResolve)){
-            	currentPair = resultPair;
-                return resolve(((PairTPHEqualTPH) resultPair).getRight());
-            }
-        }
-        for(ResultPair<?,?> resultPair : result.results){
-        	currentPair = resultPair;
-            resultPair.accept(this);
-        }
-        if(resolved==null){//TPH kommt nicht im Result vor:
-            resolved = tph;
-        }
 
-        ResolvedType result = new ResolvedType(resolved, additionalTPHs);//resolved;
+  @Override
-        result.setResultPair(currentPair);
+  public void visit(PairTPHsmallerTPH p) {
-        return result;
+    currentPair = p;
+    if (p.left.equals(toResolve)) {
+      additionalTPHs.add(new GenericInsertPair(p.left, p.right));
+      additionalTPHs.addAll(new RelatedTypeWalker(p.right, result).relatedTPHs);
     }
+    if (p.right.equals(toResolve))
+      additionalTPHs.addAll(new RelatedTypeWalker(p.left, result).relatedTPHs);
+  }
 
-    @Override
+  @Override
-    public void visit(PairTPHsmallerTPH p) {
+  public void visit(PairTPHequalRefTypeOrWildcardType p) {
-    	currentPair = p;
+    currentPair = p;
-        if(p.left.equals(toResolve)){
+    if (p.left.equals(toResolve)) {
-            additionalTPHs.add(new GenericInsertPair(p.left, p.right));
+      resolved = p.right;
-            additionalTPHs.addAll(new RelatedTypeWalker(p.right, result).relatedTPHs);
+      RelatedTypeWalker related = new RelatedTypeWalker(null, result);
-        }
+      p.right.accept(related);
-        if(p.right.equals(toResolve))
+      additionalTPHs.addAll(related.relatedTPHs);
-            additionalTPHs.addAll(new RelatedTypeWalker(p.left, result).relatedTPHs);
     }
+  }
 
-    @Override
+  @Override
-    public void visit(PairTPHequalRefTypeOrWildcardType p) {
+  public void visit(PairTPHEqualTPH p) {
-    	currentPair = p;
+    //Do nothing. Dieser Fall wird in der resolve-Methode abgefangen
-        if(p.left.equals(toResolve)){
+  }
-            resolved = p.right;
-            RelatedTypeWalker related = new RelatedTypeWalker(null, result);
-            p.right.accept(related);
-            additionalTPHs.addAll(related.relatedTPHs);
-        }
-    }
 
-    @Override
+  @Override
-    public void visit(PairTPHEqualTPH p) {
+  public void visit(RefType refType) {
-        //Do nothing. Dieser Fall wird in der resolve-Methode abgefangen
-    }
 
-    @Override
+  }
-    public void visit(RefType refType) {
 
-    }
+  @Override
+  public void visit(GenericRefType genericRefType) {
 
-    @Override
+  }
-    public void visit(GenericRefType genericRefType) {
 
-    }
+  @Override
+  public void visit(SuperWildcardType superWildcardType) {
 
-    @Override
+  }
-    public void visit(SuperWildcardType superWildcardType) {
 
-    }
+  @Override
+  public void visit(TypePlaceholder typePlaceholder) {
 
-    @Override
+  }
-    public void visit(TypePlaceholder typePlaceholder) {
 
-    }
+  @Override
+  public void visit(ExtendsWildcardType extendsWildcardType) {
 
-    @Override
+  }
-    public void visit(ExtendsWildcardType extendsWildcardType) {
 
-    }
-    
-    
 
 }
 
@@ -161,149 +198,150 @@ class Resolver implements ResultSetVisitor {
 @SuppressWarnings("rawtypes")
 class TPHResolver implements ResultSetVisitor {
 
-    private final TypePlaceholder tph;
+  private final TypePlaceholder tph;
-    Set<GenericInsertPair> resolved = new HashSet<>();
+  Set<GenericInsertPair> resolved = new HashSet<>();
-    private final ResultSet resultSet;
+  private final ResultSet resultSet;
 
-    TPHResolver(TypePlaceholder tph, ResultSet resultSet){
+  TPHResolver(TypePlaceholder tph, ResultSet resultSet) {
-        this.resultSet = resultSet;
+    this.resultSet = resultSet;
-        this.tph = tph;
+    this.tph = tph;
-        for(ResultPair p : resultSet.results){
+    for (ResultPair p : resultSet.results) {
-            p.accept(this);
+      p.accept(this);
-        }
-        if(resolved.size() == 0){
-            resolved.add(new GenericInsertPair(tph, null));
-        }
     }
-
+    if (resolved.size() == 0) {
-    @Override
+      resolved.add(new GenericInsertPair(tph, null));
-    public void visit(PairTPHsmallerTPH p) {
-        if(p.left.equals(tph) || p.right.equals(tph)){
-            resolved.add(new GenericInsertPair(p.left, p.right));
-        }
     }
+  }
 
-    @Override
+  @Override
-    public void visit(PairTPHequalRefTypeOrWildcardType p) {
+  public void visit(PairTPHsmallerTPH p) {
-        TypePlaceholder otherSide = null;
+    if (p.left.equals(tph) || p.right.equals(tph)) {
-        if(p.right.equals(tph)){
+      resolved.add(new GenericInsertPair(p.left, p.right));
-            otherSide = p.left;
-        }
-        if(otherSide != null){
-            Set<ResultPair> newResultSet = new HashSet<>(this.resultSet.results);
-            newResultSet.remove(p);
-            resolved.addAll(new TPHResolver(otherSide, new ResultSet(newResultSet)).resolved);
-        }
     }
+  }
 
-    @Override
+  @Override
-    public void visit(PairTPHEqualTPH p) {
+  public void visit(PairTPHequalRefTypeOrWildcardType p) {
-        //ignorieren. Wird vom Resolver behandelt
+    TypePlaceholder otherSide = null;
+    if (p.right.equals(tph)) {
+      otherSide = p.left;
     }
-
+    if (otherSide != null) {
-    @Override
+      Set<ResultPair> newResultSet = new HashSet<>(this.resultSet.results);
-    public void visit(RefType refType) {
+      newResultSet.remove(p);
-
+      resolved.addAll(new TPHResolver(otherSide, new ResultSet(newResultSet)).resolved);
     }
+  }
 
-    @Override
+  @Override
-    public void visit(GenericRefType genericRefType) {
+  public void visit(PairTPHEqualTPH p) {
+    //ignorieren. Wird vom Resolver behandelt
+  }
 
-    }
+  @Override
+  public void visit(RefType refType) {
 
-    @Override
+  }
-    public void visit(SuperWildcardType superWildcardType) {
 
-    }
+  @Override
+  public void visit(GenericRefType genericRefType) {
 
-    @Override
+  }
-    public void visit(TypePlaceholder typePlaceholder) {
 
-    }
+  @Override
+  public void visit(SuperWildcardType superWildcardType) {
 
-    @Override
+  }
-    public void visit(ExtendsWildcardType extendsWildcardType) {
 
-    }
+  @Override
+  public void visit(TypePlaceholder typePlaceholder) {
+
+  }
+
+  @Override
+  public void visit(ExtendsWildcardType extendsWildcardType) {
+
+  }
 }
 
 @SuppressWarnings("rawtypes")
 class RelatedTypeWalker implements ResultSetVisitor {
 
-    final Set<GenericInsertPair> relatedTPHs = new HashSet<>();
+  final Set<GenericInsertPair> relatedTPHs = new HashSet<>();
-    private final TypePlaceholder toResolve;
+  private final TypePlaceholder toResolve;
-    private final ResultSet resultSet;
+  private final ResultSet resultSet;
 
-    /**
+  /**
-     * Läuft über das resultSet und speichert alle TPHs, welche mit start in Verbindung stehen
+   * Läuft über das resultSet und speichert alle TPHs, welche mit start in Verbindung stehen
-     * @param start - kann null sein, wenn der Walker für einen RefType benutzt wird
+   *
-     * @param resultSet
+   * @param start     - kann null sein, wenn der Walker für einen RefType benutzt wird
-     */
+   * @param resultSet
-    RelatedTypeWalker(TypePlaceholder start, ResultSet resultSet){
+   */
-        this.toResolve = start;
+  RelatedTypeWalker(TypePlaceholder start, ResultSet resultSet) {
-        this.resultSet = resultSet;
+    this.toResolve = start;
-        int resolved = 0;
+    this.resultSet = resultSet;
-        do{
+    int resolved = 0;
-            resolved = relatedTPHs.size();
+    do {
-            for(ResultPair p : resultSet.results){
+      resolved = relatedTPHs.size();
-                p.accept(this);
+      for (ResultPair p : resultSet.results) {
-                p.accept(this);
+        p.accept(this);
-            }
+        p.accept(this);
-        }while(resolved - relatedTPHs.size() > 0);
+      }
-    }
+    } while (resolved - relatedTPHs.size() > 0);
+  }
 
-    @Override
+  @Override
-    public void visit(PairTPHsmallerTPH p) {
+  public void visit(PairTPHsmallerTPH p) {
-        if(p.getRight().equals(toResolve)){
+    if (p.getRight().equals(toResolve)) {
-            relatedTPHs.addAll(new TPHResolver(p.right, resultSet).resolved);
+      relatedTPHs.addAll(new TPHResolver(p.right, resultSet).resolved);
-            //relatedTPHs.addAll(new RelatedTypeWalker(p.right, resultSet).relatedTPHs);
+      //relatedTPHs.addAll(new RelatedTypeWalker(p.right, resultSet).relatedTPHs);
-        }
-        if(p.getLeft().equals(toResolve)){
-            relatedTPHs.addAll(new TPHResolver(p.left, resultSet).resolved);
-            //relatedTPHs.addAll(new RelatedTypeWalker(p.left, resultSet).relatedTPHs);
-        }
     }
+    if (p.getLeft().equals(toResolve)) {
+      relatedTPHs.addAll(new TPHResolver(p.left, resultSet).resolved);
+      //relatedTPHs.addAll(new RelatedTypeWalker(p.left, resultSet).relatedTPHs);
+    }
+  }
 
-    @Override
+  @Override
-    public void visit(PairTPHequalRefTypeOrWildcardType p) {
+  public void visit(PairTPHequalRefTypeOrWildcardType p) {
-        if(p.getLeft().equals(toResolve)){
+    if (p.getLeft().equals(toResolve)) {
-            p.getRight().accept(this);
+      p.getRight().accept(this);
-        }
     }
+  }
 
-    @Override
+  @Override
-    public void visit(PairTPHEqualTPH p) {
+  public void visit(PairTPHEqualTPH p) {
-        //Kann ignoriert werden. Diese Fälle werden vom Resolver behandelt
+    //Kann ignoriert werden. Diese Fälle werden vom Resolver behandelt
-    }
+  }
 
     /*
     Die folgenden Funktionen fügen alle TPHs an die relatedTPHs an, denen sie begegnen:
     Das wird verwendet, wenn alle relatedTPHs aus den Parametern eines RefTypes angefügt werden sollen
      */
 
-    @Override
+  @Override
-    public void visit(RefType refType) {
+  public void visit(RefType refType) {
-        for(RefTypeOrTPHOrWildcardOrGeneric param : refType.getParaList()){
+    for (RefTypeOrTPHOrWildcardOrGeneric param : refType.getParaList()) {
-            param.accept(this);
+      param.accept(this);
-        }
     }
+  }
 
-    @Override
+  @Override
-    public void visit(SuperWildcardType superWildcardType) {
+  public void visit(SuperWildcardType superWildcardType) {
-        superWildcardType.getInnerType().accept(this);
+    superWildcardType.getInnerType().accept(this);
-    }
+  }
 
-    @Override
+  @Override
-    public void visit(TypePlaceholder typePlaceholder) {
+  public void visit(TypePlaceholder typePlaceholder) {
-        relatedTPHs.addAll(new TPHResolver(typePlaceholder, resultSet).resolved);
+    relatedTPHs.addAll(new TPHResolver(typePlaceholder, resultSet).resolved);
-    }
+  }
 
-    @Override
+  @Override
-    public void visit(ExtendsWildcardType extendsWildcardType) {
+  public void visit(ExtendsWildcardType extendsWildcardType) {
-        extendsWildcardType.getInnerType().accept(this);
+    extendsWildcardType.getInnerType().accept(this);
-    }
+  }
 
-    @Override
+  @Override
-    public void visit(GenericRefType genericRefType) {
+  public void visit(GenericRefType genericRefType) {
-    }
+  }
 }

src/main/java/de/dhbwstuttgart/typeinference/typeAlgo/TYPEStmt.java

@@ -1,6 +1,7 @@
 //PL 2018-12-19: Merge chekcen
 package de.dhbwstuttgart.typeinference.typeAlgo;
 
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
 import java.util.*;
 import java.util.stream.Collectors;
 

src/main/java/de/dhbwstuttgart/typeinference/unify/CancellableTask.java

@@ -0,0 +1,62 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.RecursiveTask;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * An intermediate class for the recursive steps of the TypeUnifyTask:
+ * This allows to cancel parts of the recursion tree, instead of only  the whole execution as before. But in
+ * order for that to work, all cancellable child tasks must be added when they are created
+ *
+ * @param <T>
+ */
+public abstract class CancellableTask<T> extends RecursiveTask<T> {
+
+  private final AtomicBoolean executionCancelled = new AtomicBoolean(false);
+  private final List<CancellableTask<?>> childTasks = new ArrayList<>();
+  private CancellableTask<?> parentTask = null;
+
+  /**
+   * Set the execution for this task and all its (recursive) children to be cancelled
+   */
+  protected void cancelExecution() {
+    // is this branch already cancelled? Then do nothing
+    if (this.executionCancelled.get()) return;
+    executionCancelled.set(true);
+    this.cancelChildExecution();
+  }
+
+  public void cancelChildExecution() {
+    for (var childTask : childTasks) {
+      // no need to cancel a branch that is already finished
+      if (!childTask.isDone()) {
+        childTask.cancelExecution();
+      }
+    }
+  }
+
+  protected void cancelSiblingTasks() {
+    if (this.parentTask != null) {
+      boolean thisWasCancelledBefore = this.executionCancelled.get();
+      this.parentTask.cancelChildExecution();
+      this.executionCancelled.set(thisWasCancelledBefore);
+    }
+  }
+
+  public Boolean isExecutionCancelled() {
+    return executionCancelled.get();
+  }
+
+  public void addChildTask(CancellableTask<?> childTask) {
+    this.childTasks.add(childTask);
+    childTask.setParentTask(this);
+  }
+
+  private void setParentTask(CancellableTask<?> parentTask) {
+    this.parentTask = parentTask;
+  }
+
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/ConcurrentSetMergeTask.java

@@ -0,0 +1,64 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.RecursiveTask;
+
+public class ConcurrentSetMergeTask<T> extends RecursiveTask<Set<T>> {
+
+  public static <E> Set<E> merge(List<Set<E>> list) {
+    if (list.isEmpty()) {
+      return new HashSet<>();
+    }
+    var task = new ConcurrentSetMergeTask<>(list, 0, list.size());
+    return task.compute();
+  }
+
+  private static final int LIST_THRESHOLD = 3;
+  private static final int ELEMENT_THRESHOLD = 1000;
+
+  private final List<Set<T>> list;
+  private final int start;
+  private final int end;
+
+  private ConcurrentSetMergeTask(List<Set<T>> list, int start, int end) {
+    this.list = list;
+    this.start = start;
+    this.end = end;
+  }
+
+  @Override
+  protected Set<T> compute() {
+    int size = end - start;
+
+    int totalElements = 0;
+    for (int i = start+1; i < end; i++) {
+      totalElements += list.get(i).size();
+    }
+
+    System.out.println("ConcurrentSetMerge? -> " + (size <= LIST_THRESHOLD || totalElements < ELEMENT_THRESHOLD ? "true" : "false"));
+
+
+    // size will always be at least one
+    if (true || size <= LIST_THRESHOLD || totalElements < ELEMENT_THRESHOLD) {
+      Set<T> result = this.list.get(start);
+      for (int i = start+1; i < end; i++) {
+        result.addAll(list.get(i));
+      }
+      return result;
+    } else {
+      int mid = start + (size / 2);
+      ConcurrentSetMergeTask<T> leftTask = new ConcurrentSetMergeTask<>(list, start, mid);
+      ConcurrentSetMergeTask<T> rightTask = new ConcurrentSetMergeTask<>(list, mid, end);
+
+      leftTask.fork();
+      Set<T> rightResult = rightTask.compute();
+      Set<T> leftResult = leftTask.join();
+
+      // Merge results
+      leftResult.addAll(rightResult);
+      return leftResult;
+    }
+  }
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/PlaceholderRegistry.java

@@ -0,0 +1,84 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialValue;
+import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
+import java.util.ArrayList;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Calculate unique placeholder names
+ */
+public class PlaceholderRegistry implements ISerializableData {
+
+  private final Set<String> existingPlaceholders = ConcurrentHashMap.newKeySet();
+  private final AtomicInteger placeholderCount = new AtomicInteger();
+  public ArrayList<PlaceholderType> UnifyTypeFactory_PLACEHOLDERS = new ArrayList<>();
+
+  /**
+   * Add a placeholder into the list of existing ones, as soon as a new PlaceholderType is created
+   *
+   * @param placeholderName The placeholder to add
+   */
+  public void addPlaceholder(String placeholderName) {
+    this.existingPlaceholders.add(placeholderName);
+  }
+
+  /**
+   * Generate a random placeholder name, that is unique to this context
+   *
+   * @return  The generated name
+   */
+  public String generateFreshPlaceholderName() {
+    String name;
+    do {
+      int pc = placeholderCount.incrementAndGet();
+      name = getUppercaseTokenFromInt(pc);
+    }
+    while (existingPlaceholders.contains(name));
+    this.addPlaceholder(name);
+    return name;
+  }
+
+  public PlaceholderRegistry deepClone() {
+    PlaceholderRegistry pr2 = new PlaceholderRegistry();
+    this.existingPlaceholders.forEach(pr2::addPlaceholder);
+    pr2.UnifyTypeFactory_PLACEHOLDERS.addAll(this.UnifyTypeFactory_PLACEHOLDERS);
+    pr2.placeholderCount.set(this.placeholderCount.get());
+    return pr2;
+  }
+
+  /**
+   * Generate a token that consists of uppercase letters and contains the given prefix and suffix from the value i
+   *
+   * @param i       The value that will be represented as a token
+   * @return        The generated token
+   */
+  private String getUppercaseTokenFromInt(int i) {
+    StringBuilder sb = new StringBuilder();
+    while (i >= 0) {
+      sb.append((char)(i % 26 + 65));
+      i = i / 26 - 1;
+    }
+    //sb.append(suffix);
+    return sb.toString();
+  }
+
+  @Override
+  public String toString() {
+    return this.existingPlaceholders.toString();
+  }
+
+  @Override
+  public SerialMap toSerial(KeyStorage keyStorage) {
+    SerialMap serialized = new SerialMap();
+    serialized.put("ph", new SerialValue<>(new ArrayList<>(this.existingPlaceholders)));
+    serialized.put("factoryPh", SerialList.fromMapped(this.UnifyTypeFactory_PLACEHOLDERS, t -> t.toSerial(keyStorage)));
+    return serialized;
+  }
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/RuleSet.java

@@ -38,14 +38,17 @@ import org.apache.commons.io.output.NullOutputStream;
 public class RuleSet implements IRuleSet{
 	
 	Writer logFile;
+	final PlaceholderRegistry placeholderRegistry;
 	
-	public RuleSet() {
+	public RuleSet(PlaceholderRegistry placeholderRegistry) {
 		super();
-		logFile = new OutputStreamWriter(new NullOutputStream());
+		logFile = OutputStreamWriter.nullWriter();
+		this.placeholderRegistry = placeholderRegistry;
 	}
 	
-	RuleSet(Writer logFile) {
+	RuleSet(Writer logFile, PlaceholderRegistry placeholderRegistry) {
 		this.logFile = logFile;
+		this.placeholderRegistry = placeholderRegistry;
 	}
 	
 	@Override
@@ -864,7 +867,7 @@ public class RuleSet implements IRuleSet{
 		try {
 			logFile.write("FUNgreater: " + pair + "\n");
 				logFile.write("FUNred: " + result + "\n");
-				logFile.flush();
+				// logFile.flush();
 			}
 		catch (IOException e) {
 			System.out.println("logFile-Error");
@@ -939,10 +942,10 @@ public class RuleSet implements IRuleSet{
 		
 		UnifyType[] freshPlaceholders = new UnifyType[funNLhsType.getTypeParams().size()];
 		for(int i = 0; i < freshPlaceholders.length-1; i++) {
-			freshPlaceholders[i] = PlaceholderType.freshPlaceholder();
+			freshPlaceholders[i] = PlaceholderType.freshPlaceholder(placeholderRegistry);
 			((PlaceholderType)freshPlaceholders[i]).setVariance(inversVariance);
 		}
-		freshPlaceholders[freshPlaceholders.length-1] = PlaceholderType.freshPlaceholder();
+		freshPlaceholders[freshPlaceholders.length-1] = PlaceholderType.freshPlaceholder(placeholderRegistry);
 		((PlaceholderType)freshPlaceholders[freshPlaceholders.length-1]).setVariance(variance);
 		result.add(new UnifyPair(funNLhsType.getTypeParams().get(funNLhsType.getTypeParams().size()-1), freshPlaceholders[funNLhsType.getTypeParams().size()-1], PairOperator.SMALLERDOT, pair.getSubstitution(), pair.getBasePair()));
 		
@@ -960,7 +963,7 @@ public class RuleSet implements IRuleSet{
 		try {
 			logFile.write("FUNgreater: " + pair + "\n");
 			logFile.write("FUNgreater: " + result + "\n");
-			logFile.flush();
+			// logFile.flush();
 		}
 	catch (IOException e) {
 		System.out.println("lofFile-Error");
@@ -988,10 +991,10 @@ public class RuleSet implements IRuleSet{
 		
 		UnifyType[] freshPlaceholders = new UnifyType[funNRhsType.getTypeParams().size()];
 		for(int i = 0; i < freshPlaceholders.length-1; i++) {
-			freshPlaceholders[i] = PlaceholderType.freshPlaceholder();
+			freshPlaceholders[i] = PlaceholderType.freshPlaceholder(placeholderRegistry);
 			((PlaceholderType)freshPlaceholders[i]).setVariance(inversVariance);
 		}
-		freshPlaceholders[freshPlaceholders.length-1] = PlaceholderType.freshPlaceholder();
+		freshPlaceholders[freshPlaceholders.length-1] = PlaceholderType.freshPlaceholder(placeholderRegistry);
 		((PlaceholderType)freshPlaceholders[freshPlaceholders.length-1]).setVariance(variance);
 		
 		result.add(new UnifyPair(freshPlaceholders[funNRhsType.getTypeParams().size()-1], funNRhsType.getTypeParams().get(funNRhsType.getTypeParams().size()-1), PairOperator.SMALLERDOT, pair.getSubstitution(), pair.getBasePair()));
@@ -1010,7 +1013,7 @@ public class RuleSet implements IRuleSet{
 		try {
 			logFile.write("FUNgreater: " + pair + "\n");
 			logFile.write("FUNsmaller: " + result + "\n");
-			logFile.flush();
+			// logFile.flush();
 		}
 	catch (IOException e) {
 		System.out.println("lofFile-Error");
@@ -1051,7 +1054,7 @@ public class RuleSet implements IRuleSet{
 		if(isGen)
 			result.add(new UnifyPair(rhsType, lhsType, PairOperator.EQUALSDOT, pair.getSubstitution(), pair.getBasePair()));
 		else {
-			UnifyType freshTph = PlaceholderType.freshPlaceholder();
+			UnifyType freshTph = PlaceholderType.freshPlaceholder(placeholderRegistry);
 			result.add(new UnifyPair(rhsType, new ExtendsType(freshTph), PairOperator.EQUALSDOT, pair.getSubstitution(), pair.getBasePair()));
 			result.add(new UnifyPair(extendedType, freshTph, PairOperator.SMALLERDOT, pair.getSubstitution(), pair.getBasePair()));
 		}
@@ -1079,7 +1082,7 @@ public class RuleSet implements IRuleSet{
 		if(isGen)
 			result.add(new UnifyPair(rhsType, lhsType, PairOperator.EQUALSDOT, pair.getSubstitution(), pair.getBasePair()));
 		else {
-			UnifyType freshTph = PlaceholderType.freshPlaceholder();
+			UnifyType freshTph = PlaceholderType.freshPlaceholder(placeholderRegistry);
 			result.add(new UnifyPair(rhsType, new SuperType(freshTph), PairOperator.EQUALSDOT, pair.getSubstitution(), pair.getBasePair()));
 			Set<UnifyType> fBounded = pair.getfBounded();
 			fBounded.add(lhsType);

src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnify.java

@@ -1,41 +1,41 @@
 package de.dhbwstuttgart.typeinference.unify;
 
-import java.io.FileWriter;
+import de.dhbwstuttgart.util.Logger;
 import java.io.IOException;
-import java.io.Writer;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ForkJoinPool;
 
-import de.dhbwstuttgart.core.JavaTXCompiler;
 import de.dhbwstuttgart.typeinference.constraints.Constraint;
-import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
-import de.dhbwstuttgart.typeinference.constraints.Pair;
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
-import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
 import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
 
 public class TypeUnify {
-	
+
+	private TypeUnify() {}
+
+	private static <T> T joinFuture(CompletableFuture<T> future) {
+		try {
+			return future.get();
+		}
+		catch (InterruptedException | ExecutionException exception) {
+			throw new RuntimeException(exception);
+		}
+	}
+
 	/**
 	 * unify parallel ohne result modell
-	 * @param undConstrains
-	 * @param oderConstraints
-	 * @param fc
-	 * @param logFile
-	 * @param log
-	 * @param cons
-	 * @return
 	 */
-	public Set<Set<UnifyPair>> unify(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModel ret, UnifyTaskModel usedTasks) {
+	public static Set<Set<UnifyPair>> unify(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, UnifyContext unifyContext) {
-		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, usedTasks);
+		ForkJoinPool pool = TypeUnify.createThreadPool();
-		ForkJoinPool pool = new ForkJoinPool();
+		UnifyContext context = unifyContext.newWithParallel(true).newWithExecutor(pool);
-		pool.invoke(unifyTask);
+		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, context, 0);
-		Set<Set<UnifyPair>> res =  unifyTask.join();
+		Set<Set<UnifyPair>> res = joinFuture(unifyTask.compute());
 		try {
-			logFile.write("\nnoShortendElements: " + unifyTask.noShortendElements + "\n");
+			unifyContext.logFile().write("\nnoShortendElements: " + TypeUnifyTask.noShortendElements + "\n");
-			logFile.flush();
+			// logFile.flush();
 		}
 		catch (IOException e) {
 			System.err.println("no log-File");
@@ -45,46 +45,32 @@ public class TypeUnify {
 	
 	/**
 	 * unify asynchron mit Rückgabe UnifyResultModel ohne dass alle results gesammelt sind
-	 * @param undConstrains
-	 * @param oderConstraints
-	 * @param fc
-	 * @param logFile
-	 * @param log
-	 * @param cons
-	 * @param ret
-	 * @return
 	 */
-	public UnifyResultModel unifyAsync(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModel ret, UnifyTaskModel usedTasks) {
+	public static UnifyResultModel unifyAsync(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, UnifyContext unifyContext) {
-		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, usedTasks);
+		ForkJoinPool pool = TypeUnify.createThreadPool();
-		ForkJoinPool pool = new ForkJoinPool();
+		UnifyContext context = unifyContext.newWithExecutor(pool);
-		pool.invoke(unifyTask);
+		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, context, 0);
-		return ret;
+		unifyTask.compute();
+		return unifyContext.resultModel();
 	}
-	
+
 	/**
 	 * unify parallel mit Rückgabe UnifyResultModel nachdem alle results gesammelt sind
-	 * @param undConstrains
-	 * @param oderConstraints
-	 * @param fc
-	 * @param logFile
-	 * @param log
-	 * @param cons
-	 * @param ret
-	 * @return
 	 */
-	public UnifyResultModel unifyParallel(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModel ret, UnifyTaskModel usedTasks) {
+	public static Set<Set<UnifyPair>> unifyParallel(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, UnifyContext unifyContext) {
-		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, usedTasks);
+		ForkJoinPool pool = TypeUnify.createThreadPool();
-		ForkJoinPool pool = new ForkJoinPool();
+		UnifyContext context = unifyContext.newWithParallel(true).newWithExecutor(pool);
-		pool.invoke(unifyTask);
+		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, context, 0);
-		Set<Set<UnifyPair>> res =  unifyTask.join();
+		var result = joinFuture(unifyTask.compute());
+
 		try {
-			logFile.write("\nnoShortendElements: " + unifyTask.noShortendElements +"\n");
+			unifyContext.logFile().write("\nnoShortendElements: " + TypeUnifyTask.noShortendElements +"\n");
-			logFile.flush();
+			// logFile.flush();
 		}
 		catch (IOException e) {
 			System.err.println("no log-File");
 		}
-		return ret;
+		return result;
 	}
 	
 	/*
@@ -97,20 +83,13 @@ public class TypeUnify {
 	
 	/**
 	 * unify sequentiell mit oderconstraints
-	 * @param undConstrains
-	 * @param oderConstraints
-	 * @param fc
-	 * @param logFile
-	 * @param log
-	 * @param cons
-	 * @return
 	 */
-	public Set<Set<UnifyPair>> unifyOderConstraints(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModel ret, UnifyTaskModel usedTasks) {
+	public static Set<Set<UnifyPair>> unifyOderConstraints(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, UnifyContext unifyContext) {
-		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, false, logFile, log, 0, ret, usedTasks);
+		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, unifyContext.newWithParallel(false), 0);
-		Set<Set<UnifyPair>> res = unifyTask.compute();
+		Set<Set<UnifyPair>> res = joinFuture(unifyTask.compute());
 		try {
-			logFile.write("\nnoShortendElements: " + unifyTask.noShortendElements +"\n");
+			unifyContext.logFile().write("\nnoShortendElements: " + TypeUnifyTask.noShortendElements +"\n");
-			logFile.flush();
+			// logFile.flush();
 		}
 		catch (IOException e) {
 			System.err.println("no log-File");
@@ -118,4 +97,14 @@ public class TypeUnify {
 		return res;
 	}
 
+	private static ForkJoinPool createThreadPool() {
+		Logger.print("Available processors: " + Runtime.getRuntime().availableProcessors());
+		return new ForkJoinPool(
+			Runtime.getRuntime().availableProcessors(),
+			ForkJoinPool.defaultForkJoinWorkerThreadFactory,
+			null,
+			false
+		);
+	}
+
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnify2Task.java

@@ -13,54 +13,52 @@ import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
 import de.dhbwstuttgart.typeinference.constraints.Pair;
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
 import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import java.util.concurrent.CompletableFuture;
 
 public class TypeUnify2Task extends TypeUnifyTask {
-       
-       Set<Set<UnifyPair>> setToFlatten;
-       Set<UnifyPair> methodSignatureConstraintUebergabe;
 
-       public TypeUnify2Task(Set<Set<UnifyPair>> setToFlatten, Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, Set<UnifyPair> nextSetElement, IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModel urm, UnifyTaskModel usedTasks, Set<UnifyPair> methodSignatureConstraintUebergabe) {
+  Set<Set<UnifyPair>> setToFlatten;
-               super(eq, oderConstraints, fc, parallel, logFile, log, rekTiefe, urm, usedTasks);
+  Set<UnifyPair> methodSignatureConstraintUebergabe;
-               this.setToFlatten = setToFlatten;
+
-               this.nextSetElement = nextSetElement;
+  public TypeUnify2Task(Set<Set<UnifyPair>> setToFlatten, Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, Set<UnifyPair> nextSetElement, IFiniteClosure fc, UnifyContext context, int rekTiefe, Set<UnifyPair> methodSignatureConstraintUebergabe) {
-               this.methodSignatureConstraintUebergabe = methodSignatureConstraintUebergabe;
+    super(eq, oderConstraints, fc, context, rekTiefe);
-       }
+    this.setToFlatten = setToFlatten;
-       
+    this.nextSetElement = nextSetElement;
-       Set<UnifyPair> getNextSetElement() {
+    this.methodSignatureConstraintUebergabe = methodSignatureConstraintUebergabe;
-    	   return nextSetElement;
+  }
-       }
+
-       
+  public Set<UnifyPair> getNextSetElement() {
-       @Override
+    return nextSetElement;
-       protected Set<Set<UnifyPair>> compute() {
+  }
-               if (one) {
+
-                       System.out.println("two");
+  @Override
-               }
+  public CompletableFuture<Set<Set<UnifyPair>>> compute() {
-               one = true;
+    if (one) {
-               Set<Set<UnifyPair>> res = unify2(setToFlatten, eq, oderConstraintsField, fc, parallel, rekTiefeField, methodSignatureConstraintUebergabe);
+      System.out.println("two");
+    }
+    one = true;
+    CompletableFuture<Set<Set<UnifyPair>>> res =
+      unify2(setToFlatten, eq, oderConstraintsField, fc, context.parallel(), rekTiefeField, methodSignatureConstraintUebergabe);
                /*if (isUndefinedPairSetSet(res)) { 
                        return new HashSet<>(); }
                else
-               */ 
+               */
-               //writeLog("xxx");
+    //writeLog("xxx");
-               //noOfThread--;
+    //noOfThread--;
-               synchronized (usedTasks) {
+    if (this.myIsCancelled()) {
-            	   if (this.myIsCancelled()) {
+      return CompletableFuture.completedFuture(new HashSet<>());
-   						return new HashSet<>();
+    } else {
-   					}
+      return res;
-   					else {
+    }
-   						return res;
+  }
-   					}
-   				}
-       	}
-       
-       public void closeLogFile() {
 
-           try {
+  public void closeLogFile() {
-				logFile.close();
+
-			}
+    try {
-			catch (IOException ioE) {
+      context.logFile().close();
-				System.err.println("no log-File" + thNo);
+    } catch (IOException ioE) {
-			}
+      System.err.println("no log-File");
-           
+    }
-       }
+
+  }
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTaskHelper.java

@@ -0,0 +1,188 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import de.dhbwstuttgart.typeinference.unify.model.PairOperator;
+import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyType;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+/**
+ * A collection of capsuled (and thus static) functions to split up large algorithms in TypeUnifyTask
+ */
+public class TypeUnifyTaskHelper {
+
+  /**
+   * Filter all topLevelSets for those with a single element that contain only one pair:
+   *   a <. theta,
+   *   theta <. a or
+   *   a =. theta
+   */
+  public static Set<Set<UnifyPair>> getSingleElementSets(ArrayList<Set<? extends Set<UnifyPair>>> topLevelSets) {
+    return topLevelSets.stream()
+      .filter(x -> x.size() == 1)
+      .map(y -> y.stream().findFirst().get()).collect(Collectors.toSet());
+  }
+
+  /**
+   * Varianzbestimmung Anfang
+   * Oderconstraint, wenn entweder kein Basepair oder unterschiedliche Basepairs => oderConstraint = true;
+   * Varianz =  1 => Argumentvariable
+   * Varianz = -1 => Rückgabevariable
+   * Varianz =  0 => unklar
+   * Varianz =  2 => Operatoren oderConstraints
+   */
+  public static int calculateVariance(List<Set<UnifyPair>> nextSetasList) {
+    Optional<Integer> xi = nextSetasList.stream().map(x -> x.stream().filter(y -> (y.getLhsType() instanceof PlaceholderType && !(y.getRhsType() instanceof PlaceholderType)))
+        .filter(z -> ((PlaceholderType) z.getLhsType()).getVariance() != 0)
+        .map(c -> ((PlaceholderType) c.getLhsType()).getVariance())
+        .reduce((a, b) -> {
+          if (a.intValue() == b.intValue()) return a;
+          else return 0;
+        })) //2 kommt insbesondere bei Oder-Constraints vor
+      .filter(Optional::isPresent)
+      .map(Optional::get)
+      .findAny();
+
+    return xi.orElse(0);
+  }
+
+  /**
+   *
+   */
+  public static int calculateOderConstraintVariance(List<Set<UnifyPair>> nextSetAsList) {
+    Optional<Integer> optVariance =
+      nextSetAsList
+        .getFirst()
+        .stream()
+        .filter(x -> x.getGroundBasePair().getLhsType() instanceof PlaceholderType &&
+          !(x.getRhsType() instanceof PlaceholderType) &&
+          x.getPairOp() == PairOperator.EQUALSDOT)
+        .map(x ->
+          ((PlaceholderType) x.getGroundBasePair().getLhsType()).getVariance())
+        .reduce((n, m) -> (n != 0) ? n : m);
+
+    //Fuer Operatorenaufrufe wird variance auf 2 gesetzt.
+    //da kein Receiver existiert also kein x.getGroundBasePair().getLhsType() instanceof PlaceholderType
+    //Bei Varianz = 2 werden alle Elemente des Kartesischen Produkts abgearbeitet
+    return optVariance.orElse(2);
+  }
+
+
+  /**
+   * Find the first occurrence (if any) of a UnifyPair with operator EQUALSDOT while having
+   * one side equal to its base pair counterpart
+   */
+  public static Optional<UnifyPair> findEqualityConstrainedUnifyPair(Set<UnifyPair> nextSetElement) {
+    return nextSetElement.stream().filter(x ->
+        x.getPairOp()
+        .equals(PairOperator.EQUALSDOT))
+      .filter(x -> //Sicherstellen, dass bei a = ty a auch wirklich die gesuchte Typvariable ist
+        x.getLhsType()
+          .equals(x.getBasePair().getLhsType()) ||
+        x.getLhsType()
+          .equals(x.getBasePair().getRhsType())
+    ).findFirst();
+  }
+
+  /**
+   *  Find all unifyPairs, that associate the identified type variable of origPair with any concrete type. That means:
+   *  If "a = type" is in origPair, then we get all UnifyPairs that contain either "a < typeA" or "typeB < a"
+   */
+  public static Set<UnifyPair> findConstraintsWithSameTVAssociation(UnifyPair origPair, Set<Set<UnifyPair>> singleElementSets) {
+    UnifyType tyVar = origPair.getLhsType();
+    if (!(tyVar instanceof PlaceholderType)) {
+      tyVar = origPair.getRhsType();
+    }
+
+    UnifyType tyVarEF = tyVar;
+    return singleElementSets.stream()
+      .map(xx ->
+        xx.iterator().next())
+      .filter(x ->
+            (x.getLhsType().equals(tyVarEF) && !(x.getRhsType() instanceof PlaceholderType))
+            ||
+            (x.getRhsType().equals(tyVarEF) && !(x.getLhsType() instanceof PlaceholderType))
+      )
+      .collect(Collectors.toCollection(HashSet::new));
+  }
+
+  /**
+   *
+   */
+  public static boolean doesFirstNextSetHasSameBase(List<Set<UnifyPair>> nextSetAsList) {
+    if (nextSetAsList.isEmpty()) {
+      return false;
+    }
+
+    UnifyPair firstBasePair = null;
+
+    for (var unifyPair : nextSetAsList.getFirst().stream().toList()) {
+      var basePair = unifyPair.getBasePair();
+
+      // if any base pair is null, there is NOT always the same base!
+      if (basePair == null) {
+        return false;
+      }
+
+      if (firstBasePair == null) {
+        firstBasePair = basePair;
+      }
+      else if (!basePair.equals(firstBasePair)) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
+  /**
+   *  Extracts data from every element in the nested lists of results. What data depends on the given
+   *  extractor function
+   */
+  public static Set<UnifyPair> collectFromThreadResult (
+    Set<Set<UnifyPair>> currentThreadResult,
+    Function<UnifyPair, Set<UnifyPair>> extractor
+  ) {
+    return currentThreadResult.stream()
+      .map(b ->
+        b.stream()
+          .map(extractor)
+          .reduce((y, z) -> {
+            y.addAll(z);
+            return y;
+          })
+          .orElse(new HashSet<>()))
+      .reduce((y, z) -> {
+        y.addAll(z);
+        return y;
+      })
+      .orElse(new HashSet<>());
+  }
+
+  /**
+   *  Extract a list of PlaceholderTypes from a set of pairs, such that each resulting element:
+   *  - Is the LHS of a pair
+   *  - Is a PlaceholderType
+   *  - has a basePair Side that is a PlaceholderType with the same name
+   */
+  public static List<PlaceholderType> extractMatchingPlaceholderTypes(Set<UnifyPair> pairs) {
+    return pairs.stream()
+      .filter(x -> {
+        UnifyType lhs = x.getLhsType();
+        UnifyType baseLhs = x.getBasePair().getLhsType();
+        UnifyType baseRhs = x.getBasePair().getRhsType();
+        return (lhs instanceof PlaceholderType) &&
+          ((baseLhs instanceof PlaceholderType && lhs.getName().equals(baseLhs.getName())) ||
+            (baseRhs instanceof PlaceholderType && lhs.getName().equals(baseRhs.getName())));
+      })
+      .map(x -> (PlaceholderType) x.getLhsType())
+      .collect(Collectors.toCollection(ArrayList::new));
+  }
+
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/UnifyContext.java

@@ -0,0 +1,70 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import java.io.Writer;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public record UnifyContext(
+  // main log file of a unification
+  Writer logFile,
+  // if logs should be made
+  Boolean log,
+  // if the unify algorithm should run in parallel
+  Boolean parallel,
+  // the model for storing calculated results
+  UnifyResultModel resultModel,
+  // the executor used for thread management in parallel execution
+  ExecutorService executor,
+  // a generator for new placeholders in this unify context
+  PlaceholderRegistry placeholderRegistry,
+  // a control structure to cancel the unification early
+  UnifyTaskModel usedTasks
+) {
+
+  public UnifyContext(
+    Writer logFile,
+    Boolean log,
+    Boolean parallel,
+    UnifyResultModel resultModel,
+    UnifyTaskModel usedTasks,
+    ExecutorService executor,
+    PlaceholderRegistry placeholderRegistry
+  ) {
+    this(logFile, log, parallel, resultModel, executor, placeholderRegistry, usedTasks);
+  }
+
+  public UnifyContext(
+    Writer logFile,
+    Boolean log,
+    Boolean parallel,
+    UnifyResultModel resultModel,
+    UnifyTaskModel usedTasks,
+    PlaceholderRegistry placeholderRegistry
+  ) {
+    this(logFile, log, parallel, resultModel, usedTasks, ForkJoinPool.commonPool(), placeholderRegistry);
+  }
+
+
+  /*
+   * Shortcuts for creating a similar context with some properties changed. This combined with the final properties
+   * causes the UnifyContext to be essentially handled as a
+   */
+
+  public UnifyContext newWithLogFile(Writer logFile) {
+    return new UnifyContext(logFile, log, parallel, resultModel, executor, placeholderRegistry, usedTasks);
+  }
+
+  public UnifyContext newWithParallel(boolean parallel) {
+    return new UnifyContext(logFile, log, parallel, resultModel, executor, placeholderRegistry, usedTasks);
+  }
+
+  public UnifyContext newWithExecutor(ExecutorService executor) {
+    return new UnifyContext(logFile, log, parallel, resultModel, executor, placeholderRegistry, usedTasks);
+  }
+
+  public UnifyContext newWithResultModel(UnifyResultModel resultModel) {
+    return new UnifyContext(logFile, log, parallel, resultModel, executor, placeholderRegistry, usedTasks);
+  }
+
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/UnifyResultModel.java

@@ -36,19 +36,19 @@ public class UnifyResultModel {
 		listeners.remove(listenerToRemove);
 	}
 	
-	public void notify(Set<Set<UnifyPair>> eqPrimePrimeSet) {
+	public void notify(Set<Set<UnifyPair>> eqPrimePrimeSet, UnifyContext context) {
 		Set<Set<UnifyPair>> eqPrimePrimeSetRet = eqPrimePrimeSet.stream().map(x -> {
-			Optional<Set<UnifyPair>> res = new RuleSet().subst(x.stream().map(y -> { 
+			Optional<Set<UnifyPair>> res = new RuleSet(context.placeholderRegistry()).subst(x.stream().map(y -> {
 				if (y.getPairOp() == PairOperator.SMALLERDOTWC) y.setPairOp(PairOperator.EQUALSDOT);
 				return y; //alle Paare a <.? b erden durch a =. b ersetzt
 			}).collect(Collectors.toCollection(HashSet::new)));
 			if (res.isPresent()) {//wenn subst ein Erg liefert wurde was veraendert
-				return new TypeUnifyTask().applyTypeUnificationRules(res.get(), fc);
+				return new TypeUnifyTask(context).applyTypeUnificationRules(res.get(), fc);
 			}
 			else return x; //wenn nichts veraendert wurde wird x zurueckgegeben
 		}).collect(Collectors.toCollection(HashSet::new));
 		List<ResultSet> newResult = eqPrimePrimeSetRet.stream().map(unifyPairs ->
-           new ResultSet(UnifyTypeFactory.convert(unifyPairs, de.dhbwstuttgart.typeinference.constraints.Pair.generateTPHMap(cons))))
+           new ResultSet(UnifyTypeFactory.convert(unifyPairs, de.dhbwstuttgart.typeinference.constraints.Pair.generateTPHMap(cons), context.placeholderRegistry())))
            .collect(Collectors.toList());
 		UnifyResultEvent evt = new UnifyResultEvent(newResult);
 		

src/main/java/de/dhbwstuttgart/typeinference/unify/cartesianproduct/Variance0Case.java

@@ -0,0 +1,228 @@
+package de.dhbwstuttgart.typeinference.unify.cartesianproduct;
+
+import de.dhbwstuttgart.exceptions.UnifyCancelException;
+import de.dhbwstuttgart.typeinference.constraints.Constraint;
+import de.dhbwstuttgart.typeinference.unify.TypeUnify2Task;
+import de.dhbwstuttgart.typeinference.unify.TypeUnifyTask;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.util.Tuple;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
+
+public class Variance0Case extends VarianceCase {
+
+  protected final int variance = 0;
+
+  protected Variance0Case(boolean isOderConstraint, TypeUnifyTask typeUnifyTask, UnifyContext context) {
+    super(isOderConstraint, typeUnifyTask, context);
+  }
+
+  @Override
+  public void selectNextData(
+    TypeUnifyTask typeUnifyTask,
+    List<Set<UnifyPair>> nextSetAsList,
+    Optional<UnifyPair> optOrigPair
+
+  ) {
+    //wenn a <. theta dann ist ein maximales Element sehr wahrscheinlich
+    //wenn theta <. a dann ist ein minimales Element sehr wahrscheinlich
+    if (!this.isOderConstraint && optOrigPair != null && optOrigPair.isPresent()) {
+      if (optOrigPair.get().getBasePair().getLhsType() instanceof PlaceholderType) {
+        a = typeUnifyTask.oup.max(nextSetAsList.iterator());
+      } else {
+        a = typeUnifyTask.oup.min(nextSetAsList.iterator());
+      }
+      nextSetAsList.remove(a);
+    } else if (this.isOderConstraint) {
+      a = typeUnifyTask.oup.max(nextSetAsList.iterator());
+      nextSetAsList.remove(a);
+      nextSetasListOderConstraints.add(((Constraint<UnifyPair>) a).getExtendConstraint());
+    } else {
+      a = nextSetAsList.removeFirst();
+    }
+
+
+    Set<UnifyPair> finalA = a;
+    if (!this.isOderConstraint && optOrigPair != null && optOrigPair.isPresent()) {
+      if (optOrigPair.get().getBasePair().getLhsType() instanceof PlaceholderType) {
+        nextSetasListRest = typeUnifyTask.oup.maxElements(
+          nextSetAsList.stream().filter(a_next -> typeUnifyTask.oup.compare(finalA, a_next) != 1).toList()
+        );
+      } else {
+        nextSetasListRest = typeUnifyTask.oup.minElements(
+          nextSetAsList.stream().filter(a_next -> typeUnifyTask.oup.compare(finalA, a_next) != -1).toList()
+        );
+      }
+      nextSetAsList.remove(a);
+    } else if (this.isOderConstraint) {
+      nextSetasListRest = typeUnifyTask.oup.maxElements(
+        nextSetAsList.stream().filter(a_next -> typeUnifyTask.oup.compare(finalA, a_next) != 1).toList()
+      );
+    } else {
+      for (int i = 0; i < Math.min(nextSetAsList.size(), 5); i++) {
+        nextSetasListRest.add(nextSetAsList.removeFirst());
+      }
+    }
+  }
+
+  @Override
+  public CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> computeParallel(
+    Set<Set<UnifyPair>> elems,
+    Set<UnifyPair> eq,
+    List<Set<Constraint<UnifyPair>>> oderConstraints,
+    IFiniteClosure fc,
+    int rekTiefe,
+    Set<UnifyPair> methodSignatureConstraint,
+    List<Set<UnifyPair>> nextSetAsList,
+    Set<UnifyPair> sameEqSet,
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> aParDef
+  ) {
+    CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> resultValues = CompletableFuture.completedFuture(new Tuple<>(
+      new HashSet<>(), new HashSet<>()
+    ));
+
+    Set<UnifyPair> newEqOrig = new HashSet<>(eq);
+    Set<Set<UnifyPair>> newElemsOrig = new HashSet<>(elems);
+    List<Set<Constraint<UnifyPair>>> newOderConstraintsOrig = new ArrayList<>(oderConstraints);
+    newElemsOrig.add(a);
+
+    /* FORK ANFANG */
+    TypeUnify2Task forkOrig = new TypeUnify2Task(newElemsOrig, newEqOrig, newOderConstraintsOrig, a, fc, context, rekTiefe, new HashSet<>(methodSignatureConstraint));
+    typeUnifyTask.addChildTask(forkOrig);
+    // schedule compute() on another thread
+    CompletableFuture<Set<Set<UnifyPair>>> forkOrigFuture = CompletableFuture.supplyAsync(forkOrig::compute, context.executor()).thenCompose(f -> f);
+    resultValues = resultValues.thenCombine(forkOrigFuture,
+      (prevResults, currentThreadResult) -> {
+        forkOrig.writeLog("final Orig 0");
+        forkOrig.closeLogFile();
+        return new Tuple<>(currentThreadResult, prevResults.getSecond());
+      });
+
+    //forks.add(forkOrig);
+    if (typeUnifyTask.myIsCancelled()) {
+      throw new UnifyCancelException();
+    }
+    /* FORK ENDE */
+
+    writeLog("a in " + variance + " " + a);
+    writeLog("nextSetasListRest: " + nextSetasListRest.toString());
+
+    while (!nextSetasListRest.isEmpty()) {
+      Set<UnifyPair> nSaL = nextSetasListRest.removeFirst();
+      nextSetAsList.remove(nSaL);
+      writeLog("0 RM" + nSaL.toString());
+
+      if (!this.isOderConstraint) {
+        //ueberpruefung ob zu a =. ty \in nSaL in sameEqSet ein Widerspruch besteht
+        if (!sameEqSet.isEmpty() && !typeUnifyTask.checkNoContradiction(nSaL, sameEqSet, result)) {
+          TypeUnifyTask.noShortendElements++;
+          continue;
+        }
+      } else {
+        nextSetasListOderConstraints.add(((Constraint<UnifyPair>) nSaL).getExtendConstraint());
+      }
+      Set<UnifyPair> newEq = new HashSet<>(eq);
+      Set<Set<UnifyPair>> newElems = new HashSet<>(elems);
+      List<Set<Constraint<UnifyPair>>> newOderConstraints = new ArrayList<>(oderConstraints);
+      newElems.add(nSaL);
+      TypeUnify2Task fork = new TypeUnify2Task(newElems, newEq, newOderConstraints, nSaL, fc, context, rekTiefe, new HashSet<>(methodSignatureConstraint));
+      typeUnifyTask.addChildTask(fork);
+      // schedule compute() on another thread
+      CompletableFuture<Set<Set<UnifyPair>>> forkFuture = CompletableFuture.supplyAsync(fork::compute, context.executor()).thenCompose(f -> f);
+      resultValues = resultValues.thenCombine(forkFuture,
+        (prevResults, fork_res) -> {
+          if (typeUnifyTask.myIsCancelled()) {
+            throw new UnifyCancelException();
+          }
+          writeLog("fork_res: " + fork_res.toString());
+          writeLog(Boolean.valueOf((typeUnifyTask.isUndefinedPairSetSet(fork_res))).toString());
+          prevResults.getSecond().add(fork_res);
+          if (!typeUnifyTask.isUndefinedPairSetSet(fork_res)) {
+            aParDef.add(fork.getNextSetElement());
+          }
+          fork.writeLog("final 0");
+          fork.closeLogFile();
+          return prevResults;
+        }
+      );
+
+      if (typeUnifyTask.myIsCancelled()) {
+        throw new UnifyCancelException();
+      }
+    }
+
+    return resultValues;
+  }
+
+  @Override
+  public void applyComputedResults(
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> currentThreadResult,
+    Set<UnifyPair> compResult,
+    Set<UnifyPair> compRes
+  ) {
+    writeLog("RES var=0 ADD:" + result.toString() + " " + currentThreadResult.toString());
+    result.addAll(currentThreadResult);
+  }
+
+  @Override
+  public boolean eraseInvalidSets(
+    int rekTiefe,
+    Set<Set<UnifyPair>> aParDef,
+    List<Set<UnifyPair>> nextSetAsList
+  ) {
+    if (!this.isOderConstraint) {
+      return true;
+    } else {
+
+      nextSetAsList.removeAll(nextSetasListOderConstraints);
+      nextSetasListOderConstraints = new ArrayList<>();
+      writeLog("Removed: " + nextSetasListOderConstraints);
+      final List<Set<UnifyPair>> smallerSetasList = typeUnifyTask.oup.smallerThan(a, nextSetAsList);
+      List<Set<UnifyPair>> notInherited = smallerSetasList.stream()
+        .filter(x -> !((Constraint<UnifyPair>) x).isInherited())
+        .collect(Collectors.toCollection(ArrayList::new));
+      final List<Set<UnifyPair>> notErased = new ArrayList<>();
+      notInherited.forEach(x -> notErased.addAll(typeUnifyTask.oup.smallerEqThan(x, smallerSetasList)));
+      List<Set<UnifyPair>> erased = new ArrayList<>(smallerSetasList);
+      erased.removeAll(notErased);
+      nextSetAsList.removeAll(erased);
+      writeLog("Removed: " + erased);
+      writeLog("Not Removed: " + nextSetAsList);
+
+      for (Set<UnifyPair> aPar : aParDef) {
+
+        nextSetAsList.removeAll(nextSetasListOderConstraints);
+        nextSetasListOderConstraints = new ArrayList<>();
+        writeLog("Removed: " + nextSetasListOderConstraints);
+        smallerSetasList.clear();
+        smallerSetasList.addAll(typeUnifyTask.oup.smallerThan(aPar, nextSetAsList));
+        notInherited = smallerSetasList.stream()
+          .filter(x -> !((Constraint<UnifyPair>) x).isInherited())
+          .collect(Collectors.toCollection(ArrayList::new));
+        notErased.clear();
+        notInherited.forEach(x -> notErased.addAll(typeUnifyTask.oup.smallerEqThan(x, smallerSetasList)));
+        erased = new ArrayList<>(smallerSetasList);
+        erased.removeAll(notErased);
+        nextSetAsList.removeAll(erased);
+        writeLog("Removed: " + erased);
+        writeLog("Not Removed: " + nextSetAsList);
+      }
+
+    }
+
+    return false;
+  }
+
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/cartesianproduct/Variance1Case.java

@@ -0,0 +1,214 @@
+package de.dhbwstuttgart.typeinference.unify.cartesianproduct;
+
+import de.dhbwstuttgart.exceptions.UnifyCancelException;
+import de.dhbwstuttgart.typeinference.constraints.Constraint;
+import de.dhbwstuttgart.typeinference.unify.TypeUnify2Task;
+import de.dhbwstuttgart.typeinference.unify.TypeUnifyTask;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.util.Tuple;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.stream.Collectors;
+
+public class Variance1Case extends VarianceCase {
+
+  protected final int variance = 1;
+
+  protected Variance1Case(boolean isOderConstraint, TypeUnifyTask typeUnifyTask, UnifyContext context) {
+    super(isOderConstraint, typeUnifyTask, context);
+  }
+
+  @Override
+  public void selectNextData(
+    TypeUnifyTask typeUnifyTask,
+    List<Set<UnifyPair>> nextSetAsList,
+    Optional<UnifyPair> optOrigPair
+  ) {
+    a = typeUnifyTask.oup.max(nextSetAsList.iterator());
+    writeLog("Max: a in " + variance + " " + a);
+    nextSetAsList.remove(a);
+    if (this.isOderConstraint) {
+      nextSetasListOderConstraints.add(((Constraint<UnifyPair>) a).getExtendConstraint());
+    }
+    writeLog("nextSetasListOderConstraints 1: " + nextSetasListOderConstraints);
+
+    //Alle maximale Elemente in nextSetasListRest bestimmen
+    //nur für diese wird parallele Berechnung angestossen.
+    Set<UnifyPair> finalA = a;
+    nextSetasListRest = typeUnifyTask.oup.maxElements(
+      nextSetAsList.stream().filter(a_next -> typeUnifyTask.oup.compare(finalA, a_next) != 1).toList()
+    );
+  }
+
+
+  @Override
+  public CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> computeParallel(
+    Set<Set<UnifyPair>> elems,
+    Set<UnifyPair> eq,
+    List<Set<Constraint<UnifyPair>>> oderConstraints,
+    IFiniteClosure fc,
+    int rekTiefe,
+    Set<UnifyPair> methodSignatureConstraint,
+    List<Set<UnifyPair>> nextSetAsList,
+    Set<UnifyPair> sameEqSet,
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> aParDef
+  ) {
+    CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> resultValues = CompletableFuture.completedFuture(new Tuple<>(
+      new HashSet<>(), new HashSet<>()
+    ));
+
+    Set<UnifyPair> newEqOrig = new HashSet<>(eq);
+    Set<Set<UnifyPair>> newElemsOrig = new HashSet<>(elems);
+    List<Set<Constraint<UnifyPair>>> newOderConstraintsOrig = new ArrayList<>(oderConstraints);
+    newElemsOrig.add(a);
+
+    /* FORK ANFANG */
+    TypeUnify2Task forkOrig = new TypeUnify2Task(newElemsOrig, newEqOrig, newOderConstraintsOrig, a, fc, context, rekTiefe, methodSignatureConstraint);
+    typeUnifyTask.addChildTask(forkOrig);
+    // schedule compute() on another thread
+    CompletableFuture<Set<Set<UnifyPair>>> forkOrigFuture = CompletableFuture.supplyAsync(forkOrig::compute, context.executor()).thenCompose(f -> f);
+    resultValues = resultValues.thenCombine(forkOrigFuture,
+      (prevResults, currentThreadResult) -> {
+        forkOrig.writeLog("final Orig 1");
+        forkOrig.closeLogFile();
+        return new Tuple<>(currentThreadResult, prevResults.getSecond());
+      });
+
+    //forks.add(forkOrig);
+    if (typeUnifyTask.myIsCancelled()) {
+      throw new UnifyCancelException();
+    }
+    /* FORK ENDE */
+
+    writeLog("a in " + variance + " " + a);
+    writeLog("nextSetasListRest: " + nextSetasListRest.toString());
+    while (!nextSetasListRest.isEmpty()) {
+      Set<UnifyPair> nSaL = nextSetasListRest.removeFirst();
+      nextSetAsList.remove(nSaL);
+      writeLog("1 RM" + nSaL.toString());
+
+      if (!this.isOderConstraint) {
+        //ueberpruefung ob zu a =. ty \in nSaL in sameEqSet ein Widerspruch besteht
+        if (!sameEqSet.isEmpty() && !typeUnifyTask.checkNoContradiction(nSaL, sameEqSet, result)) {
+          TypeUnifyTask.noShortendElements++;
+          continue;
+        }
+      } else {
+        nextSetasListOderConstraints.add(((Constraint<UnifyPair>) nSaL).getExtendConstraint());
+      }
+      Set<UnifyPair> newEq = new HashSet<>(eq);
+      Set<Set<UnifyPair>> newElems = new HashSet<>(elems);
+      List<Set<Constraint<UnifyPair>>> newOderConstraints = new ArrayList<>(oderConstraints);
+      newElems.add(nSaL);
+      TypeUnify2Task fork = new TypeUnify2Task(newElems, newEq, newOderConstraints, nSaL, fc, context, rekTiefe, new HashSet<>(methodSignatureConstraint));
+      typeUnifyTask.addChildTask(fork);
+      // schedule compute() on another thread
+      CompletableFuture<Set<Set<UnifyPair>>> forkFuture = CompletableFuture.supplyAsync(fork::compute, context.executor()).thenCompose(f -> f);
+      resultValues = resultValues.thenCombine(forkFuture,
+        (prevResults, fork_res) -> {
+          if (typeUnifyTask.myIsCancelled()) {
+            throw new UnifyCancelException();
+          }
+          writeLog("fork_res: " + fork_res.toString());
+          writeLog(Boolean.valueOf((typeUnifyTask.isUndefinedPairSetSet(fork_res))).toString());
+          prevResults.getSecond().add(fork_res);
+          if (!typeUnifyTask.isUndefinedPairSetSet(fork_res)) {
+            aParDef.add(fork.getNextSetElement());
+          }
+          fork.writeLog("final 1");
+          fork.closeLogFile();
+        return prevResults;
+        }
+      );
+
+      if (typeUnifyTask.myIsCancelled()) {
+        throw new UnifyCancelException();
+      }
+    }
+
+    return resultValues;
+  }
+
+  @Override
+  public void applyComputedResults(
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> currentThreadResult,
+    Set<UnifyPair> compResult,
+    Set<UnifyPair> compRes
+  ) {
+    int resOfCompare = typeUnifyTask.oup.compare(compResult, compRes);
+    if (resOfCompare == -1) {
+      writeLog("Geloescht result: " + result);
+      result.clear();
+      result.addAll(currentThreadResult);
+    }
+    else if (resOfCompare == 0) {
+      result.addAll(currentThreadResult);
+    }
+    else if (resOfCompare == 1) {
+      writeLog("Geloescht currentThreadResult: " + currentThreadResult);
+      //result = result;
+    }
+  }
+
+  @Override
+  public boolean eraseInvalidSets(
+    int rekTiefe,
+    Set<Set<UnifyPair>> aParDef,
+    List<Set<UnifyPair>> nextSetAsList
+  ) {
+    // System.out.println("");
+    writeLog("a: " + rekTiefe + " variance: " + variance + a.toString());
+    writeLog("aParDef: " + aParDef.toString());
+    aParDef.add(a);
+    Iterator<Set<UnifyPair>> aParDefIt = aParDef.iterator();
+    if (this.isOderConstraint) {
+      nextSetAsList.removeAll(nextSetasListOderConstraints);
+      nextSetasListOderConstraints = new ArrayList<>();
+      writeLog("Removed: " + nextSetasListOderConstraints);
+      while (aParDefIt.hasNext()) {
+        Set<UnifyPair> a_new = aParDefIt.next();
+        List<Set<UnifyPair>> smallerSetasList = typeUnifyTask.oup.smallerThan(a_new, nextSetAsList);
+        writeLog("smallerSetasList: " + smallerSetasList);
+        List<Set<UnifyPair>> notInherited = smallerSetasList.stream()
+          .filter(x -> !((Constraint<UnifyPair>) x).isInherited() && !((Constraint<UnifyPair>) x).isImplemented())
+          .collect(Collectors.toCollection(ArrayList::new));
+        writeLog("notInherited: " + notInherited + "\n");
+        List<Set<UnifyPair>> notErased = new ArrayList<>();
+        notInherited.forEach(x -> {
+          notErased.addAll(typeUnifyTask.oup.smallerEqThan(x, smallerSetasList));
+        });
+        List<Set<UnifyPair>> erased = new ArrayList<>(smallerSetasList);
+        writeLog("notErased: " + notErased + "\n");
+        erased.removeAll(notErased);
+        nextSetAsList.removeAll(erased);
+
+        writeLog("Removed: " + erased);
+
+        writeLog("Not Removed: " + nextSetAsList);
+
+      }
+    } else {
+      while (aParDefIt.hasNext()) {
+        //nextSetasListIt = nextSetasList.iterator(); Sollte eingefuegt werden PL 2020-04-28
+        Set<UnifyPair> a_new = aParDefIt.next();
+        List<Set<UnifyPair>> erased = typeUnifyTask.oup.smallerEqThan(a_new, nextSetAsList);
+        nextSetAsList.removeAll(erased);
+
+        writeLog("Removed: " + erased);
+
+        writeLog("Not Removed: " + nextSetAsList);
+      }
+    }
+
+    return false;
+  }
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/cartesianproduct/Variance2Case.java

@@ -0,0 +1,137 @@
+package de.dhbwstuttgart.typeinference.unify.cartesianproduct;
+
+import de.dhbwstuttgart.exceptions.UnifyCancelException;
+import de.dhbwstuttgart.typeinference.constraints.Constraint;
+import de.dhbwstuttgart.typeinference.unify.TypeUnify2Task;
+import de.dhbwstuttgart.typeinference.unify.TypeUnifyTask;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.util.Tuple;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+
+public class Variance2Case extends VarianceCase {
+
+  protected final int variance = 2;
+
+  protected Variance2Case(boolean isOderConstraint, TypeUnifyTask typeUnifyTask, UnifyContext context) {
+    super(isOderConstraint, typeUnifyTask, context);
+  }
+
+  @Override
+  public void selectNextData(
+    TypeUnifyTask typeUnifyTask,
+    List<Set<UnifyPair>> nextSetAsList,
+    Optional<UnifyPair> optOrigPair
+
+  ) {
+    a = nextSetAsList.removeFirst();
+    //Fuer alle Elemente wird parallele Berechnung angestossen.
+    nextSetasListRest = new ArrayList<>(nextSetAsList);
+  }
+
+
+  @Override
+  public CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> computeParallel(
+    Set<Set<UnifyPair>> elems,
+    Set<UnifyPair> eq,
+    List<Set<Constraint<UnifyPair>>> oderConstraints,
+    IFiniteClosure fc,
+    int rekTiefe,
+    Set<UnifyPair> methodSignatureConstraint,
+    List<Set<UnifyPair>> nextSetAsList,
+    Set<UnifyPair> sameEqSet,
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> aParDef
+  ) {
+    CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> resultValuesFuture;
+
+    writeLog("var2einstieg");
+    Set<TypeUnify2Task> forks = new HashSet<>();
+    Set<UnifyPair> newEqOrig = new HashSet<>(eq);
+    Set<Set<UnifyPair>> newElemsOrig = new HashSet<>(elems);
+    List<Set<Constraint<UnifyPair>>> newOderConstraintsOrig = new ArrayList<>(oderConstraints);
+    newElemsOrig.add(a);
+
+    /* FORK ANFANG */
+    TypeUnify2Task forkOrig = new TypeUnify2Task(newElemsOrig, newEqOrig, newOderConstraintsOrig, a, fc, context, rekTiefe, new HashSet<>(methodSignatureConstraint));
+    typeUnifyTask.addChildTask(forkOrig);
+    CompletableFuture<Set<Set<UnifyPair>>> forkOrigFuture = CompletableFuture.supplyAsync(forkOrig::compute, context.executor()).thenCompose(f -> f);
+    resultValuesFuture = forkOrigFuture.thenApply((currentThreadResult) -> {
+      forkOrig.writeLog("final Orig 2");
+      forkOrig.closeLogFile();
+      return new Tuple<>(currentThreadResult, new HashSet<>());
+    });
+    if (typeUnifyTask.myIsCancelled()) {
+      throw new UnifyCancelException();
+    }
+    /* FORK ENDE */
+
+    writeLog("a in " + variance + " " + a);
+    writeLog("nextSetasListRest: " + nextSetasListRest.toString());
+
+    //Fuer parallele Berechnung der Oder-Contraints wird methodSignature kopiert
+    //und jeweils die methodSignature von a bzw. nSaL wieder gelöscht, wenn es keine Lösung ist.
+    Set<UnifyPair> methodSignatureConstraintForParallel = new HashSet<>(methodSignatureConstraint);
+    Set<UnifyPair> nSaL = a;
+
+    while (!nextSetasListRest.isEmpty()) {
+      methodSignatureConstraintForParallel.removeAll(((Constraint<UnifyPair>) nSaL).getmethodSignatureConstraint());
+      nSaL = nextSetasListRest.removeFirst();
+      nextSetAsList.remove(nSaL); //PL einkommentiert 20-02-03
+      methodSignatureConstraintForParallel.addAll(((Constraint<UnifyPair>) nSaL).getmethodSignatureConstraint());
+      Set<UnifyPair> newEq = new HashSet<>(eq);
+      Set<Set<UnifyPair>> newElems = new HashSet<>(elems);
+      List<Set<Constraint<UnifyPair>>> newOderConstraints = new ArrayList<>(oderConstraints);
+      newElems.add(nSaL);
+      TypeUnify2Task fork = new TypeUnify2Task(newElems, newEq, newOderConstraints, nSaL, fc, context, rekTiefe, new HashSet<>(methodSignatureConstraintForParallel));
+      typeUnifyTask.addChildTask(fork);
+      CompletableFuture<Set<Set<UnifyPair>>> forkFuture = CompletableFuture.supplyAsync(fork::compute, context.executor()).thenCompose(f -> f);
+      resultValuesFuture = resultValuesFuture.thenCombine(forkFuture, (resultValues, fork_res) -> {
+        if (typeUnifyTask.myIsCancelled()) {
+          throw new UnifyCancelException();
+        }
+        resultValues.getSecond().add(fork_res);
+        fork.writeLog("final 2");
+        fork.closeLogFile();
+        return resultValues;
+      });
+
+      if (typeUnifyTask.myIsCancelled()) {
+        throw new UnifyCancelException();
+      }
+    }
+
+    if (typeUnifyTask.myIsCancelled()) {
+      throw new UnifyCancelException();
+    }
+
+    return resultValuesFuture;
+  }
+
+  @Override
+  public void applyComputedResults(
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> currentThreadResult,
+    Set<UnifyPair> compResult,
+    Set<UnifyPair> compRes
+  ) {
+    // Nothing
+  }
+
+  @Override
+  public boolean eraseInvalidSets(
+    int rekTiefe,
+    Set<Set<UnifyPair>> aParDef,
+    List<Set<UnifyPair>> nextSetAsList
+  ) {
+    // Nothing
+    return false;
+  }
+
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/cartesianproduct/VarianceCase.java

@@ -0,0 +1,112 @@
+package de.dhbwstuttgart.typeinference.unify.cartesianproduct;
+
+import de.dhbwstuttgart.typeinference.constraints.Constraint;
+import de.dhbwstuttgart.typeinference.unify.TypeUnifyTask;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.util.Logger;
+import de.dhbwstuttgart.util.Tuple;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+
+public abstract class VarianceCase {
+
+  public static VarianceCase createFromVariance(int variance, boolean isOderConstraint, TypeUnifyTask typeUnifyTask, UnifyContext context) {
+    return switch (variance) {
+      case 0 -> new Variance0Case(isOderConstraint, typeUnifyTask, context);
+      case 1 -> new Variance1Case(isOderConstraint, typeUnifyTask, context);
+      case -1 -> new VarianceM1Case(isOderConstraint, typeUnifyTask, context);
+      case 2 -> new Variance2Case(isOderConstraint, typeUnifyTask, context);
+      default -> throw new RuntimeException("Invalid variance: " + variance);
+    };
+  }
+
+  protected final boolean isOderConstraint;
+  protected final TypeUnifyTask typeUnifyTask;
+  protected final UnifyContext context;
+
+  /**
+   * Aktueller Fall
+   */
+  public Set<UnifyPair> a;
+
+  /**
+   * Liste der Faelle für die parallele Verarbeitung
+   * Enthaelt Elemente, die nicht in Relation zu aktuellem Fall in der
+   * Variablen a stehen. Diese muesse auf alle Faelle bearbeitet werden,
+   * Deshalb wird ihre Berechnung parallel angestossen.
+   */
+  public List<Set<UnifyPair>> nextSetasListRest = new ArrayList<>();
+
+  /**
+   * Liste der Faelle, bei dem Receiver jeweils "? extends" enthaelt bzw. nicht enthaelt
+   * In der Regel ist dies genau ein Element
+   * Dieses Element wird später aus nextSetasList geloescht, wenn das jeweils andere Element zum Erfolg
+   * gefuehrt hat.
+   */
+  public List<Set<UnifyPair>> nextSetasListOderConstraints = new ArrayList<>();
+
+
+  protected VarianceCase(boolean isOderConstraint, TypeUnifyTask typeUnifyTask, UnifyContext context) {
+    this.isOderConstraint = isOderConstraint;
+    this.typeUnifyTask = typeUnifyTask;
+    this.context = context;
+  }
+
+  /**
+   *  Selects values for the next iteration in the run method:
+   *  - a : The element to ???
+   *  - nextSetAsList: The list of cases that have no relation to the selected a and will have to be worked on
+   *  - nextSetasListOderConstraints: The list of cases of which the receiver contains "? extends", typically one element
+   */
+  public abstract void selectNextData(
+    TypeUnifyTask typeUnifyTask,
+    List<Set<UnifyPair>> nextSetAsList,
+    Optional<UnifyPair> optOrigPair
+  );
+
+  /**
+   *
+   */
+  public abstract CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> computeParallel(
+    Set<Set<UnifyPair>> elems,
+    Set<UnifyPair> eq,
+    List<Set<Constraint<UnifyPair>>> oderConstraints,
+    IFiniteClosure fc,
+    int rekTiefe,
+    Set<UnifyPair> methodSignatureConstraint,
+    List<Set<UnifyPair>> nextSetAsList,
+    Set<UnifyPair> sameEqSet,
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> aParDef
+  );
+
+  /**
+   *
+   */
+  public abstract void applyComputedResults(
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> currentThreadResult,
+    Set<UnifyPair> compResult,
+    Set<UnifyPair> compRes
+  );
+
+  /**
+   *
+   * @return If the current iteration should be broken out of
+   */
+  public abstract boolean eraseInvalidSets(
+    int rekTiefe,
+    Set<Set<UnifyPair>> aParDef,
+    List<Set<UnifyPair>> nextSetAsList
+  );
+
+  protected void writeLog(String s) {
+    typeUnifyTask.writeLog(s);
+  }
+
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/cartesianproduct/VarianceM1Case.java

@@ -0,0 +1,231 @@
+package de.dhbwstuttgart.typeinference.unify.cartesianproduct;
+
+import de.dhbwstuttgart.exceptions.UnifyCancelException;
+import de.dhbwstuttgart.typeinference.constraints.Constraint;
+import de.dhbwstuttgart.typeinference.unify.TypeUnify2Task;
+import de.dhbwstuttgart.typeinference.unify.TypeUnifyTask;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.util.Tuple;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.stream.Collectors;
+
+public class VarianceM1Case extends VarianceCase {
+
+  protected final int variance = -1;
+
+  protected VarianceM1Case(boolean isOderConstraint, TypeUnifyTask typeUnifyTask, UnifyContext context) {
+    super(isOderConstraint, typeUnifyTask, context);
+  }
+
+  @Override
+  public void selectNextData(
+    TypeUnifyTask typeUnifyTask,
+    List<Set<UnifyPair>> nextSetAsList,
+    Optional<UnifyPair> optOrigPair
+  ) {
+    a = typeUnifyTask.oup.min(nextSetAsList.iterator());
+    writeLog("Min: a in " + variance + " " + a);
+    if (this.isOderConstraint) {
+      nextSetasListOderConstraints.add(((Constraint<UnifyPair>) a).getExtendConstraint());
+    }
+    writeLog("nextSetasListOderConstraints -1: " + nextSetasListOderConstraints);
+    nextSetAsList.remove(a);
+
+    //Alle minimalen Elemente in nextSetasListRest bestimmen
+    //nur für diese wird parallele Berechnung angestossen.
+    Set<UnifyPair> finalA = a;
+    nextSetasListRest = typeUnifyTask.oup.minElements(
+      nextSetAsList.stream().filter(a_next -> typeUnifyTask.oup.compare(finalA, a_next) != -1).toList()
+    );
+  }
+
+
+  @Override
+  public CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> computeParallel(
+    Set<Set<UnifyPair>> elems,
+    Set<UnifyPair> eq,
+    List<Set<Constraint<UnifyPair>>> oderConstraints,
+    IFiniteClosure fc,
+    int rekTiefe,
+    Set<UnifyPair> methodSignatureConstraint,
+    List<Set<UnifyPair>> nextSetAsList,
+    Set<UnifyPair> sameEqSet,
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> aParDef
+  ) {
+    CompletableFuture<Tuple<Set<Set<UnifyPair>>, Set<Set<Set<UnifyPair>>>>> resultValues = CompletableFuture.completedFuture(new Tuple<>(
+      new HashSet<>(), new HashSet<>()
+    ));
+
+    Set<UnifyPair> newEqOrig = new HashSet<>(eq);
+    Set<Set<UnifyPair>> newElemsOrig = new HashSet<>(elems);
+    List<Set<Constraint<UnifyPair>>> newOderConstraintsOrig = new ArrayList<>(oderConstraints);
+    newElemsOrig.add(a);
+
+    /* FORK ANFANG */
+    TypeUnify2Task forkOrig = new TypeUnify2Task(newElemsOrig, newEqOrig, newOderConstraintsOrig, a, fc, context, rekTiefe, methodSignatureConstraint);
+    typeUnifyTask.addChildTask(forkOrig);
+    // schedule compute() on another thread
+    CompletableFuture<Set<Set<UnifyPair>>> forkOrigFuture = CompletableFuture.supplyAsync(forkOrig::compute, context.executor()).thenCompose(f -> f);
+    resultValues = resultValues.thenCombine(forkOrigFuture,
+      (prevResults, currentThreadResult) -> {
+        forkOrig.writeLog("final Orig -1");
+        forkOrig.closeLogFile();
+        return new Tuple<>(currentThreadResult, prevResults.getSecond());
+      });
+
+    //forks.add(forkOrig);
+    if (typeUnifyTask.myIsCancelled()) {
+      throw new UnifyCancelException();
+    }
+    /* FORK ENDE */
+
+    writeLog("a in " + variance + " " + a);
+    writeLog("nextSetasListRest: " + nextSetasListRest.toString());
+
+    while (!nextSetasListRest.isEmpty()) {
+      Set<UnifyPair> nSaL = nextSetasListRest.removeFirst();
+      nextSetAsList.remove(nSaL);
+      writeLog("-1 RM" + nSaL.toString());
+
+      if (!this.isOderConstraint) {
+        //ueberpruefung ob zu a =. ty \in nSaL in sameEqSet ein Widerspruch besteht
+        if (!sameEqSet.isEmpty() && !typeUnifyTask.checkNoContradiction(nSaL, sameEqSet, result)) {
+          TypeUnifyTask.noShortendElements++;
+          continue;
+        }
+      } else {
+        nextSetasListOderConstraints.add(((Constraint<UnifyPair>) nSaL).getExtendConstraint());
+      }
+      Set<UnifyPair> newEq = new HashSet<>(eq);
+      Set<Set<UnifyPair>> newElems = new HashSet<>(elems);
+      List<Set<Constraint<UnifyPair>>> newOderConstraints = new ArrayList<>(oderConstraints);
+      newElems.add(nSaL);
+      TypeUnify2Task fork = new TypeUnify2Task(newElems, newEq, newOderConstraints, nSaL, fc, context, rekTiefe, new HashSet<>(methodSignatureConstraint));
+      typeUnifyTask.addChildTask(fork);
+      // schedule compute() on another thread
+      CompletableFuture<Set<Set<UnifyPair>>> forkFuture = CompletableFuture.supplyAsync(fork::compute, context.executor()).thenCompose(f -> f);
+      resultValues = resultValues.thenCombine(forkFuture,
+        (prevResults, fork_res) -> {
+          if (typeUnifyTask.myIsCancelled()) {
+            throw new UnifyCancelException();
+          }
+          writeLog("fork_res: " + fork_res.toString());
+          writeLog(Boolean.valueOf((typeUnifyTask.isUndefinedPairSetSet(fork_res))).toString());
+          prevResults.getSecond().add(fork_res);
+          if (!typeUnifyTask.isUndefinedPairSetSet(fork_res)) {
+            aParDef.add(fork.getNextSetElement());
+          }
+          fork.writeLog("final -1");
+          fork.closeLogFile();
+        return prevResults;
+        }
+      );
+
+      if (typeUnifyTask.myIsCancelled()) {
+        throw new UnifyCancelException();
+      }
+    }
+
+    return resultValues;
+  }
+
+
+  @Override
+  public void applyComputedResults(
+    Set<Set<UnifyPair>> result,
+    Set<Set<UnifyPair>> currentThreadResult,
+    Set<UnifyPair> compResult,
+    Set<UnifyPair> compRes
+  ) {
+    int resOfCompare = typeUnifyTask.oup.compare(compResult, compRes);
+    if (resOfCompare == 1) {
+      writeLog("Geloescht result: " + result);
+      result.clear();
+      result.addAll(currentThreadResult);
+    } else if (resOfCompare == 0) {
+      result.addAll(currentThreadResult);
+    } else if (resOfCompare == -1) {
+      writeLog("Geloescht currentThreadResult: " + currentThreadResult);
+      //result = result;
+    }
+  }
+
+  @Override
+  public boolean eraseInvalidSets(
+    int rekTiefe,
+    Set<Set<UnifyPair>> aParDef,
+    List<Set<UnifyPair>> nextSetAsList
+  ) {
+
+    // System.out.println("");
+    writeLog("a: " + rekTiefe + " variance: " + variance + a.toString());
+    writeLog("aParDef: " + aParDef.toString());
+    aParDef.add(a);
+    Iterator<Set<UnifyPair>> aParDefIt = aParDef.iterator();
+    if (this.isOderConstraint) {
+      nextSetAsList.removeAll(nextSetasListOderConstraints);
+      writeLog("Removed: " + nextSetasListOderConstraints);
+      nextSetasListOderConstraints = new ArrayList<>();
+      while (aParDefIt.hasNext()) {
+        Set<UnifyPair> a_new = aParDefIt.next();
+        List<Set<UnifyPair>> greaterSetasList = typeUnifyTask.oup.greaterThan(a_new, nextSetAsList);
+
+        //a_new muss hingefuegt werden, wenn es nicht vererbt ist, dann wird es spaeter wieder geloescht
+        if (!((Constraint<UnifyPair>) a_new).isInherited()) {
+          greaterSetasList.add(a_new);
+        }
+        List<Set<UnifyPair>> notInherited = greaterSetasList.stream()
+          .filter(x -> !((Constraint<UnifyPair>) x).isInherited())
+          .collect(Collectors.toCollection(ArrayList::new));
+        List<Set<UnifyPair>> notErased = new ArrayList<>();
+
+        //Wenn x nicht vererbt ist, beginnt beim naechstgroesseren Element die naechste Ueberladung
+        notInherited.forEach(x -> {
+          notErased.addAll(typeUnifyTask.oup.greaterEqThan(x, greaterSetasList));
+        });
+
+        //das kleineste Element ist das Element von dem a_new geerbt hat
+        //muss deshalb geloescht werden
+        Iterator<Set<UnifyPair>> notErasedIt = notErased.iterator();
+        if (notErasedIt.hasNext()) {
+          Set<UnifyPair> min = typeUnifyTask.oup.min(notErasedIt);
+          notErased.remove(min);
+          notErased.remove(((Constraint<UnifyPair>) min).getExtendConstraint());
+        }
+
+        List<Set<UnifyPair>> erased = new ArrayList<>(greaterSetasList);
+        erased.removeAll(notErased);
+        nextSetAsList.removeAll(erased);
+
+        writeLog("Removed: " + erased);
+
+        writeLog("Not Removed: " + nextSetAsList);
+
+      }
+    } else {
+      while (aParDefIt.hasNext()) {
+        //nextSetasListIt = nextSetasList.iterator(); Sollte eingefuegt werden PL 2020-04-28
+        Set<UnifyPair> a_new = aParDefIt.next();
+        List<Set<UnifyPair>> erased = typeUnifyTask.oup.greaterEqThan(a_new, nextSetAsList);
+
+        nextSetAsList.removeAll(erased);
+
+        writeLog("Removed: " + erased);
+
+        writeLog("Not Removed: " + nextSetAsList);
+      }
+    }
+
+    return false;
+  }
+
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/interfaces/IFiniteClosure.java

@@ -1,6 +1,7 @@
 package de.dhbwstuttgart.typeinference.unify.interfaces;
 
-import java.util.List;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.util.Optional;
 import java.util.Set;
 
@@ -18,9 +19,8 @@ import org.antlr.v4.runtime.Token;
  * 
  * @author Florian Steurer
  */
-public interface IFiniteClosure {
+public interface IFiniteClosure extends ISerializableData {
 	
-	public void setLogTrue();
 	/**
 	 * Returns all types of the finite closure that are subtypes of the argument.
 	 * @return The set of subtypes of the argument.
@@ -74,5 +74,5 @@ public interface IFiniteClosure {
 	public Set<UnifyType> getChildren(UnifyType t);
 	public Set<UnifyType> getAllTypesByName(String typeName);
 
-	public int compare(UnifyType rhsType, UnifyType rhsType2, PairOperator pairop);
+	public int compare(UnifyType rhsType, UnifyType rhsType2, PairOperator pairop, UnifyContext context);
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/model/ExtendsType.java

@@ -1,8 +1,9 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
-import java.util.ArrayList;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
-import java.util.Collection;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
-import java.util.HashMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
@@ -11,7 +12,7 @@ import de.dhbwstuttgart.typeinference.unify.interfaces.UnifyTypeVisitor;
 /**
  * An extends wildcard type "? extends T". 
  */
-public final class ExtendsType extends WildcardType {
+public final class ExtendsType extends WildcardType implements ISerializableData  {
 	
 	public <T> UnifyType accept(UnifyTypeVisitor<T> visitor, T ht) {
 		return visitor.visit(this, ht);
@@ -92,5 +93,21 @@ public final class ExtendsType extends WildcardType {
 		return "? extends " + wildcardedType;
 	}
 
+	@Override
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		serialized.put("wildcardedType", this.wildcardedType.toSerial(keyStorage));
+
+		// create the wrapper and put this as the object
+		var serializedWrapper = super.toSerial(keyStorage).assertType(SerialMap.class);
+		serializedWrapper.put("object", serialized);
+		return serializedWrapper;
+	}
+
+	public static ExtendsType fromSerial(SerialMap data, UnifyContext context) {
+		return new ExtendsType(
+			UnifyType.fromSerial(data.getMap("wildcardedType"), context)
+		);
+	}
 	
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/model/FiniteClosure.java

@@ -1,16 +1,20 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
-import java.io.FileWriter;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.io.IOException;
 import java.io.Writer;
-import java.lang.reflect.Modifier;
-import java.sql.Array;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Hashtable;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.BiFunction;
@@ -18,40 +22,28 @@ import java.util.function.BinaryOperator;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
-import com.google.common.collect.Ordering;
-
 //PL 18-02-05/18-04-05 Unifier durch Matcher ersetzt
 //muss greater noch ersetzt werden ja erledigt 18--04-05
 import de.dhbwstuttgart.core.JavaTXCompiler;
 import de.dhbwstuttgart.parser.SourceLoc;
-import de.dhbwstuttgart.parser.scope.JavaClassName;
-import de.dhbwstuttgart.syntaxtree.factory.UnifyTypeFactory;
-import de.dhbwstuttgart.syntaxtree.type.RefTypeOrTPHOrWildcardOrGeneric;
-import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
-import de.dhbwstuttgart.typeinference.unify.MartelliMontanariUnify;
 
 import de.dhbwstuttgart.typeinference.unify.Match;
 import de.dhbwstuttgart.typeinference.unify.TypeUnifyTask;
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
-import de.dhbwstuttgart.typeinference.unify.interfaces.IUnify;
 import de.dhbwstuttgart.util.Pair;
 import org.antlr.v4.runtime.Token;
-import org.apache.commons.io.output.NullWriter;
 
 /**
  * The finite closure for the type unification
  * @author Florian Steurer
  */
-public class FiniteClosure //extends Ordering<UnifyType> //entfernt PL 2018-12-11
+public class FiniteClosure implements IFiniteClosure, ISerializableData {
-implements IFiniteClosure  {
 
 	final JavaTXCompiler compiler;
+	final PlaceholderRegistry placeholderRegistry;
 
 	Writer logFile;
-	static Boolean log = false;
+
-	public void setLogTrue() {
-		log = true;
-	}
 	/**
 	 * A map that maps every type to the node in the inheritance graph that contains that type.
 	 */
@@ -81,8 +73,9 @@ implements IFiniteClosure  {
 	/**
 	 * Creates a new instance using the inheritance tree defined in the pairs.
 	 */
-	public FiniteClosure(Set<UnifyPair> pairs, Writer logFile, JavaTXCompiler compiler) {
+	public FiniteClosure(Set<UnifyPair> pairs, Writer logFile, JavaTXCompiler compiler, PlaceholderRegistry placeholderRegistry) {
 		this.compiler = compiler;
+		this.placeholderRegistry = placeholderRegistry;
 		this.logFile = logFile;
 		this.pairs = new HashSet<>(pairs);
 		inheritanceGraph = new HashMap<UnifyType, Node<UnifyType>>();
@@ -141,13 +134,13 @@ implements IFiniteClosure  {
 		}
 	}
 	
-	public FiniteClosure(Set<UnifyPair> constraints, Writer writer) {
+	public FiniteClosure(Set<UnifyPair> constraints, Writer writer, PlaceholderRegistry placeholderRegistry) {
-		this(constraints, writer, null);
+		this(constraints, writer, null, placeholderRegistry);
 	}
 
 	void testSmaller() {
 		UnifyType tq1, tq2, tq3;
-		tq1 = new ExtendsType(PlaceholderType.freshPlaceholder());
+		tq1 = new ExtendsType(PlaceholderType.freshPlaceholder(placeholderRegistry));
 		List<UnifyType> l1 = new ArrayList<>();
 		List<UnifyType> l2 = new ArrayList<>();
 		l1.add(tq1);
@@ -207,7 +200,7 @@ implements IFiniteClosure  {
 				result.add(new Pair<>(t, fBounded));
 			}
 			catch (StackOverflowError e) {
-				System.out.println("");
+				// System.out.println("");
 			}
 			
 			// if C<...> <* C<...> then ... (third case in definition of <*)
@@ -698,10 +691,10 @@ implements IFiniteClosure  {
 	}
 	*/
 	
-	public int compare (UnifyType left, UnifyType right, PairOperator pairop) {
+	public int compare (UnifyType left, UnifyType right, PairOperator pairop, UnifyContext context) {
 		try {logFile.write("left: "+ left + " right: " + right + " pairop: " + pairop +"\n");} catch (IOException ie) {}
-		if (left.getName().equals("Matrix") || right.getName().equals("Matrix")) 
+		// if (left.getName().equals("Matrix") || right.getName().equals("Matrix"))
-			System.out.println("");
+		// 	System.out.println("");
 		/*
 		pairop = PairOperator.SMALLERDOTWC;
 		List<UnifyType> al = new ArrayList<>();
@@ -752,7 +745,7 @@ implements IFiniteClosure  {
 			}
 		}
 		UnifyPair up = new UnifyPair(left, right, pairop);
-		TypeUnifyTask unifyTask = new TypeUnifyTask();
+		TypeUnifyTask unifyTask = new TypeUnifyTask(context);
 		HashSet<UnifyPair> hs = new HashSet<>();
 		hs.add(up);
 		Set<UnifyPair> smallerRes = unifyTask.applyTypeUnificationRules(hs, this);
@@ -760,7 +753,7 @@ implements IFiniteClosure  {
 		//if (left.getName().equals("Vector") || right.getName().equals("AbstractList")) 
 		{try { 
 			logFile.write("\nsmallerRes: " + smallerRes);//"smallerHash: " + greaterHash.toString());
-			logFile.flush();
+			// logFile.flush();
 		}
 		catch (IOException e) {
 			System.err.println("no LogFile");}}
@@ -774,7 +767,7 @@ implements IFiniteClosure  {
 		long smallerLen = smallerRes.stream().filter(delFun).count();
 		try { 
 			logFile.write("\nsmallerLen: " + smallerLen +"\n");
-			logFile.flush();
+			// logFile.flush();
 		}
 		catch (IOException e) {
 			System.err.println("no LogFile");}
@@ -789,7 +782,7 @@ implements IFiniteClosure  {
 			//if (left.getName().equals("Vector") || right.getName().equals("AbstractList")) 
 			{try { 
 				logFile.write("\ngreaterRes: " + greaterRes);//"smallerHash: " + greaterHash.toString());
-				logFile.flush();
+				// logFile.flush();
 			}
 			catch (IOException e) {
 				System.err.println("no LogFile");}}
@@ -803,4 +796,18 @@ implements IFiniteClosure  {
 			}
 		}	
 	}
+
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		serialized.put("pairs", SerialList.fromMapped(this.pairs, unifyPair -> unifyPair.toSerial(keyStorage)));
+		return serialized;
+	}
+
+	public static FiniteClosure fromSerial(SerialMap data, UnifyContext context, KeyStorage keyStorage) {
+		var pairList = data.getList("pairs").assertListOfUUIDs();
+		Set<UnifyPair> pairs = pairList.stream()
+			.map(pairData -> UnifyPair.fromSerial(pairData, context, keyStorage)).collect(Collectors.toSet());
+		return new FiniteClosure(pairs, context.logFile(), context.placeholderRegistry());
+	}
+
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/model/FunInterfaceType.java

@@ -1,14 +1,17 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
-import de.dhbwstuttgart.parser.scope.JavaClassName;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
-import de.dhbwstuttgart.syntaxtree.factory.UnifyTypeFactory;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialValue;
 
-import java.lang.reflect.Modifier;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
-public class FunInterfaceType extends ReferenceType  {
+public class FunInterfaceType extends ReferenceType implements ISerializableData {
     final List<UnifyType> intfArgTypes;
     final UnifyType intfReturnType;
     final List<String> generics;
@@ -46,4 +49,29 @@ public class FunInterfaceType extends ReferenceType  {
 
         return args;
     }
+
+    @Override
+    public SerialMap toSerial(KeyStorage keyStorage) {
+        var serializedWrapper = super.toSerial(keyStorage);
+        SerialMap serialized = serializedWrapper.getMap("object");
+
+        serialized.put("intfArgTypes", SerialList.fromMapped(intfArgTypes, u -> u.toSerial(keyStorage)));
+        serialized.put("intfReturnType", intfReturnType.toSerial(keyStorage));
+        serialized.put("generics", SerialList.fromMapped(generics, SerialValue::new));
+
+        return serializedWrapper;
+    }
+
+    public static FunInterfaceType fromSerial(SerialMap data, UnifyContext context) {
+        var name = data.getValue("name").getOf(String.class);
+        var params = data.getList("params").assertListOfMaps().stream().map(
+          paramData -> UnifyType.fromSerial(paramData, context)).toList();
+        var intfArgTypes = data.getList("intfArgTypes").assertListOfMaps().stream().map(
+          argTypeData -> UnifyType.fromSerial(argTypeData, context)).toList();
+        var intfReturnType = UnifyType.fromSerial(data.getMap("intfReturnType"), context);
+        var generics = data.getList("generics").assertListOfValues().stream().map(
+          generic -> generic.getOf(String.class)).toList();
+
+        return new FunInterfaceType(name, new TypeParams(params), intfArgTypes, intfReturnType, generics);
+    }
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/model/FunNType.java

@@ -1,8 +1,13 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.HashMap;
+import java.util.List;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
@@ -12,7 +17,7 @@ import de.dhbwstuttgart.typeinference.unify.interfaces.UnifyTypeVisitor;
  * A real function type in java.
  * @author Florian Steurer
  */
-public class FunNType extends UnifyType {
+public class FunNType extends UnifyType implements ISerializableData {
 
 	public <T> UnifyType accept(UnifyTypeVisitor<T> visitor, T ht) {
 		return visitor.visit(this, ht);
@@ -99,5 +104,22 @@ public class FunNType extends UnifyType {
 
 		return other.getTypeParams().equals(typeParams);
 	}
-	
+
+	@Override
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		serialized.put("params", SerialList.fromMapped(this.typeParams.get(), param -> param.toSerial(keyStorage)));
+
+		// create the wrapper and put this as the object
+		var serializedWrapper = super.toSerial(keyStorage);
+		serializedWrapper.put("object", serialized);
+		return serializedWrapper;
+	}
+
+	public static FunNType fromSerial(SerialMap data, UnifyContext context) {
+		List<UnifyType> params = data.getList("params").assertListOfMaps().stream().map(
+			paramData -> UnifyType.fromSerial(paramData, context)).toList();
+		return new FunNType(new TypeParams(params));
+	}
+
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/model/OrderingUnifyPair.java

@@ -1,5 +1,6 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -26,9 +27,11 @@ import de.dhbwstuttgart.util.Pair;
 public class OrderingUnifyPair extends OrderingExtend<Set<UnifyPair>> {
 	
 	protected IFiniteClosure fc;
-	
+	protected UnifyContext context;
-	public OrderingUnifyPair(IFiniteClosure fc) {
+
+	public OrderingUnifyPair(IFiniteClosure fc, UnifyContext context) {
 		this.fc = fc;
+		this.context = context;
 	}
 	
 	/*
@@ -39,15 +42,15 @@ public class OrderingUnifyPair extends OrderingExtend<Set<UnifyPair>> {
 		try {
 		//if (left.getRhsType() instanceof WildcardType || right.getRhsType() instanceof WildcardType) {//PL 2019-01-12 ausgetauscht
 		if (((PlaceholderType)left.getLhsType()).isInnerType() && ((PlaceholderType)right.getLhsType()).isInnerType()) {
-			return fc.compare(left.getRhsType(), right.getRhsType(), PairOperator.SMALLERDOTWC);
+			return fc.compare(left.getRhsType(), right.getRhsType(), PairOperator.SMALLERDOTWC, context);
 		}
 			else	 {
-				return fc.compare(left.getRhsType(), right.getRhsType(), PairOperator.SMALLERDOT);
+				return fc.compare(left.getRhsType(), right.getRhsType(), PairOperator.SMALLERDOT, context);
 		}}
 		catch (ClassCastException e) {
 			try {
 			((FiniteClosure)fc).logFile.write("ClassCastException: " + left.toString() + " " + left.getGroundBasePair() + "\n\n");
-			((FiniteClosure)fc).logFile.flush();
+			 // ((FiniteClosure)fc).logFile.flush();
 			}
 			catch (IOException ie) {
 			}
@@ -79,18 +82,18 @@ public class OrderingUnifyPair extends OrderingExtend<Set<UnifyPair>> {
 						&& (((ExtendsType)right).getExtendedType().getName().equals("java.util.Vector"))
 						&& (((ReferenceType)((ExtendsType)right).getExtendedType()).getTypeParams().iterator().next() instanceof ExtendsType)))
 				{
-					System.out.println("");
+					// System.out.println("");
 				}
 				if (((right instanceof SuperType) && (((SuperType)right).getSuperedType().getName().equals("java.lang.Object")))
 		||((left instanceof SuperType) && (((SuperType)left).getSuperedType().getName().equals("java.lang.Object"))))
 {
-						System.out.println("");
+						// System.out.println("");
 					}
 		}
 			else	 {
 				up = new UnifyPair(left, right, PairOperator.SMALLERDOT);
 		}
-		TypeUnifyTask unifyTask = new TypeUnifyTask();
+		TypeUnifyTask unifyTask = new TypeUnifyTask(context);
 		HashSet<UnifyPair> hs = new HashSet<>();
 		hs.add(up);
 		Set<UnifyPair> smallerRes = unifyTask.applyTypeUnificationRules(hs, fc);
@@ -106,11 +109,11 @@ public class OrderingUnifyPair extends OrderingExtend<Set<UnifyPair>> {
 						&& (((ExtendsType)right).getExtendedType().getName().equals("java.util.Vector"))
 						&& (((ReferenceType)((ExtendsType)right).getExtendedType()).getTypeParams().iterator().next() instanceof ExtendsType)))
 				{
-					System.out.println("");
+					// System.out.println("");
 				}
 				if (right instanceof SuperType) 
 					{
-						System.out.println("");
+						// System.out.println("");
 					}
 			}
 				else	 {
@@ -411,13 +414,13 @@ public class OrderingUnifyPair extends OrderingExtend<Set<UnifyPair>> {
 					if (leftlewc.iterator().next().getLhsType() instanceof PlaceholderType) {
 						hm = rsleuni.stream().reduce(new HashMap<UnifyType,UnifyPair>(), (x, y)-> { x.put(y.getLhsType(),y); return x; }, combiner);
 						Stream<UnifyPair> lslewcstr = lsleuni.stream().filter(x -> !(hm.get(x.getLhsType()) == null));
-						si = lslewcstr.map(x -> fc.compare(x.getRhsType(), hm.get(x.getLhsType()).getRhsType(), PairOperator.SMALLERDOTWC)).reduce((x,y)-> { if (x == y) return x; else return 0; } );
+						si = lslewcstr.map(x -> fc.compare(x.getRhsType(), hm.get(x.getLhsType()).getRhsType(), PairOperator.SMALLERDOTWC, context)).reduce((x,y)-> { if (x == y) return x; else return 0; } );
 					}
 					//4. Fall
 					else {
 						hm = rsleuni.stream().reduce(new HashMap<UnifyType,UnifyPair>(), (x, y)-> { x.put(y.getRhsType(),y); return x; }, combiner);
 						Stream<UnifyPair> lslewcstr = lsleuni.stream().filter(x -> !(hm.get(x.getRhsType()) == null));
-						si = lslewcstr.map(x -> fc.compare(x.getLhsType(), hm.get(x.getRhsType()).getLhsType(), PairOperator.SMALLERDOTWC)).reduce((x,y)-> { if (x == y) return x; else return 0; } );
+						si = lslewcstr.map(x -> fc.compare(x.getLhsType(), hm.get(x.getRhsType()).getLhsType(), PairOperator.SMALLERDOTWC, context)).reduce((x,y)-> { if (x == y) return x; else return 0; } );
 					}
 					if (!si.isPresent()) return 0;
 					else return si.get();

src/main/java/de/dhbwstuttgart/typeinference/unify/model/PairOperator.java

@@ -46,4 +46,15 @@ public enum PairOperator {
 			default: return "=."; // EQUALSDOT
 		}
 	}
+
+	public static PairOperator fromString(String op) {
+		switch (op) {
+			case "<": return SMALLER;
+			case "<.": return SMALLERDOT;
+			case "<!=.": return SMALLERNEQDOT;
+			case "<.?": return SMALLERDOTWC;
+			case "=.": return EQUALSDOT;
+			default: throw new RuntimeException("Unknown PairOperator: " + op);
+		}
+	}
 }

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

@@ -1,119 +1,96 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
-import java.io.File;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
-import java.io.FileWriter;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
-import java.util.ArrayList;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
-import java.util.Collection;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
-import java.util.HashMap;
-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;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Set;
 
 /**
  * An unbounded placeholder type.
  * @author Florian Steurer
  */
 public final class PlaceholderType extends UnifyType{
-	
+
-	/**
-	 * Static list containing the names of all existing placeholders.
-	 * Used for generating fresh placeholders.
-	 */
-	public static final ArrayList<String> EXISTING_PLACEHOLDERS = new ArrayList<String>();
-	
-	/**
-	 * Prefix of auto-generated placeholder names.
-	 */
-	protected static String nextName = "gen_";
-	
-	/**
-	 * Random number generator used to generate fresh placeholder name.
-	 */
-	protected static Random rnd = new Random(43558747548978L);
-	
 	/**
 	 * True if this object was auto-generated, false if this object was user-generated.
 	 */
 	private final boolean IsGenerated;
-	
+
-	
+
 	/**
-	 * isWildcardable gibt an, ob ein Wildcardtyp dem PlaceholderType zugeordnet werden darf 
+	 * isWildcardable gibt an, ob ein Wildcardtyp dem PlaceholderType zugeordnet werden darf
 	 */
-	private boolean wildcardable = true;  
+	private boolean wildcardable = true;
-	
+
 	/**
 	 * is innerType gibt an, ob der Type des PlaceholderType innerhalb eines Typkonstruktorsverwendet wird
 	 */
-	private boolean innerType = false;  
+	private boolean innerType = false;
-	
+
 	/**
-     * variance shows the variance of the pair
+	 * variance shows the variance of the pair
-     * 1: contravariant
+	 * 1: contravariant
-     * -1 covariant
+	 * -1 covariant
-     * 0 invariant
+	 * 0 invariant
-     * PL 2018-03-21
+	 * PL 2018-03-21
-     */
+	 */
-    private int variance = 0;
+	private int variance = 0;
-    
+
-    /*
+	/*
-     * Fuer Oder-Constraints:
+	 * Fuer Oder-Constraints:
-     * orCons = 1: Receiver
+	 * orCons = 1: Receiver
-     * orCons = 0: Argument oder kein Oder-Constraint 
+	 * orCons = 0: Argument oder kein Oder-Constraint
-     * orCons = -1: RetType
+	 * orCons = -1: RetType
-     */
+	 */
-    private byte orCons = 0;
+	private byte orCons = 0;
-	
+
 	/**
 	 * Creates a new placeholder type with the specified name.
 	 */
-	public PlaceholderType(String name) {
+	public PlaceholderType(String name, PlaceholderRegistry placeholderRegistry) {
 		super(name, new TypeParams());
-		EXISTING_PLACEHOLDERS.add(name); // Add to list of existing placeholder names
+		placeholderRegistry.addPlaceholder(name); // Add to list of existing placeholder names
 		IsGenerated = false; // This type is user generated
 	}
-	
+
-	
+
-	public PlaceholderType(String name, int variance) {
+	public PlaceholderType(String name, int variance, PlaceholderRegistry placeholderRegistry) {
 		super(name, new TypeParams());
-		EXISTING_PLACEHOLDERS.add(name); // Add to list of existing placeholder names
+		placeholderRegistry.addPlaceholder(name); // Add to list of existing placeholder names
 		IsGenerated = false; // This type is user generated
 		this.variance = variance;
 	}
-	
+
 	/**
-	 * Creates a new placeholdertype 
+	 * Creates a new placeholdertype
 	 * @param isGenerated true if this placeholder is auto-generated, false if it is user-generated.
 	 */
-	protected PlaceholderType(String name, boolean isGenerated) {
+	protected PlaceholderType(String name, boolean isGenerated, PlaceholderRegistry placeholderRegistry) {
 		super(name, new TypeParams());
-		EXISTING_PLACEHOLDERS.add(name); // Add to list of existing placeholder names
+		placeholderRegistry.addPlaceholder(name); // Add to list of existing placeholder names
 		IsGenerated = isGenerated;
 	}
-	
+
 	public <T> UnifyType accept(UnifyTypeVisitor<T> visitor, T ht) {
 		return visitor.visit(this, ht);
 	}
-	
+
 	/**
-	 * Creates a fresh placeholder type with a name that does so far not exist.
+	 * Creates a fresh placeholder type with a name that does so far not exist from the chars A-Z.
 	 * A user could later instantiate a type using the same name that is equivalent to this type.
 	 * @return A fresh placeholder type.
 	 */
-	public synchronized static PlaceholderType freshPlaceholder() {
+	public static PlaceholderType freshPlaceholder(PlaceholderRegistry placeholderRegistry) {
-		String name = nextName + (char) (rnd.nextInt(22) + 97); // Returns random char between 'a' and 'z'
+		var name = placeholderRegistry.generateFreshPlaceholderName();
-		// Add random chars while the name is in use.
+		return new PlaceholderType(name, true, placeholderRegistry);
-		while(EXISTING_PLACEHOLDERS.contains(name)) {
-			name += (char) (rnd.nextInt(22) + 97); // Returns random char between 'a' and 'z'
-		}
-		return new PlaceholderType(name, true);
 	}
-	
+
-	
+
 	/**
 	 * True if this placeholder is auto-generated, false if it is user-generated.
 	 */
@@ -124,51 +101,51 @@ public final class PlaceholderType extends UnifyType{
 	public void setVariance(int v) {
 		variance = v;
 	}
-	
+
 	public int getVariance() {
 		return variance;
 	}
-	
+
 	public void reversVariance() {
 		if (variance == 1) {
 			setVariance(-1);
 		} else {
-	    if (variance == -1) {
+			if (variance == -1) {
-			setVariance(1);
+				setVariance(1);
-		}}
+			}}
 	}
-	
+
 	public void setOrCons(byte i) {
 		orCons = i;
 	}
-	
+
 	public byte getOrCons() {
 		return orCons;
 	}
-	
+
 	public Boolean isWildcardable() {
 		return wildcardable;
 	}
 	public void disableWildcardtable() {
 		wildcardable = false;
 	}
-	
+
 	public void enableWildcardtable() {
 		wildcardable = true;
 	}
-	
+
 	public void setWildcardtable(Boolean wildcardable) {
 		this.wildcardable = wildcardable;
 	}
-	
+
 	public Boolean isInnerType() {
 		return innerType;
 	}
-	
+
 	public void setInnerType(Boolean innerType) {
 		this.innerType = innerType;
 	}
-	
+
 	@Override
 	Set<UnifyType> smArg(IFiniteClosure fc, Set<UnifyType> fBounded) {
 		return fc.smArg(this, fBounded);
@@ -178,17 +155,17 @@ public final class PlaceholderType extends UnifyType{
 	Set<UnifyType> grArg(IFiniteClosure fc, Set<UnifyType> fBounded) {
 		return fc.grArg(this, fBounded);
 	}
-	
+
 	@Override
 	public UnifyType setTypeParams(TypeParams newTp) {
 		return this; // Placeholders never have params.
 	}
-	
+
 	@Override
 	public int hashCode() {
 		return typeName.hashCode();
 	}
-	
+
 	@Override
 	UnifyType apply(Unifier unif) {
 		if(unif.hasSubstitute(this)) {
@@ -200,15 +177,15 @@ public final class PlaceholderType extends UnifyType{
 		}
 		return this;
 	}
-	
+
 	@Override
 	public boolean equals(Object obj) {
 		if(!(obj instanceof PlaceholderType))
 			return false;
-		
+
 		return ((PlaceholderType) obj).getName().equals(typeName);
 	}
-	
+
 
 	@Override
 	public Collection<PlaceholderType> getInvolvedPlaceholderTypes() {
@@ -216,4 +193,39 @@ public final class PlaceholderType extends UnifyType{
 		ret.add(this);
 		return ret;
 	}
+
+
+	@Override
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		serialized.put("name", this.typeName);
+		// Placeholders never make use of the typeParams
+		serialized.put("isGenerated", IsGenerated);
+		serialized.put("wildcardable", wildcardable);
+		serialized.put("isInnerType", innerType);
+		serialized.put("variance", variance);
+		serialized.put("orCons", orCons);
+
+		// create the wrapper and put this as the object
+		var serializedWrapper = super.toSerial(keyStorage);
+		serializedWrapper.put("object", serialized);
+		return serializedWrapper;
+	}
+
+	public static PlaceholderType fromSerial(SerialMap data, UnifyContext context) {
+		var name 				= data.getValue("name").getOf(String.class);
+		var isGenerated = data.getValue("isGenerated").getOf(Boolean.class);
+		var wildcardable = data.getValue("wildcardable").getOf(Boolean.class);
+		var isInnerType = data.getValue("isInnerType").getOf(Boolean.class);
+		var variance 		= data.getValue("variance").getOf(Integer.class);
+		var orCons 			= data.getValue("orCons").getOf(Number.class).byteValue();
+
+		var placeholderType = new PlaceholderType(name, isGenerated, context.placeholderRegistry());
+		placeholderType.setWildcardtable(wildcardable);
+		placeholderType.setInnerType(isInnerType);
+		placeholderType.setVariance(variance);
+		placeholderType.setOrCons(orCons);
+
+		return placeholderType;
+	}
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/model/ReferenceType.java

@@ -1,6 +1,10 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
-import java.util.HashMap;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
@@ -11,45 +15,51 @@ import de.dhbwstuttgart.typeinference.unify.interfaces.UnifyTypeVisitor;
  * @author Florian Steurer
  *
  */
-public class ReferenceType extends UnifyType {
+public class ReferenceType extends UnifyType implements ISerializableData {
-	
+
 	/**
 	 * The buffered hashCode
 	 */
 	private final int hashCode;
-	
+
 	/**
 	 * gibt an, ob der ReferenceType eine generische Typvariable ist
 	 */
 	private final boolean genericTypeVar;
-	
+
 
 	public <T> UnifyType accept(UnifyTypeVisitor<T> visitor, T ht) {
 		return visitor.visit(this, ht);
 	}
-	
+
 	public ReferenceType(String name, Boolean genericTypeVar) {
 		super(name, new TypeParams());
 		hashCode = 31 + 17 * typeName.hashCode() + 17 * typeParams.hashCode();
 		this.genericTypeVar = genericTypeVar;
 	}
-	
+
 	public ReferenceType(String name, UnifyType... params) {
 		super(name, new TypeParams(params));
 		hashCode = 31 + 17 * typeName.hashCode() + 17 * typeParams.hashCode();
 		genericTypeVar = false;
 	}
-	
+
 	public ReferenceType(String name, TypeParams params) {
 		super(name, params);
 		hashCode = 31 + 17 * typeName.hashCode() + 17 * typeParams.hashCode();
 		genericTypeVar = false;
 	}
 
-	public boolean isGenTypeVar () { 
+	private ReferenceType(String name, TypeParams params, boolean genericTypeVar) {
+		super(name, params);
+		hashCode = 31 + 17 * typeName.hashCode() + 17 * typeParams.hashCode();
+		this.genericTypeVar = genericTypeVar;
+	}
+
+	public boolean isGenTypeVar() {
 		return genericTypeVar;
 	}
-	
+
 	@Override
 	Set<UnifyType> smArg(IFiniteClosure fc, Set<UnifyType> fBounded) {
 		return fc.smArg(this, fBounded);
@@ -63,38 +73,59 @@ public class ReferenceType extends UnifyType {
 	@Override
 	UnifyType apply(Unifier unif) {
 		TypeParams newParams = typeParams.apply(unif);
-		
+
-		if(newParams.hashCode() == typeParams.hashCode() && newParams.equals(typeParams))
+		if (newParams.hashCode() == typeParams.hashCode() && newParams.equals(typeParams))
 			return this;
-		
+
 		return new ReferenceType(typeName, newParams);
 	}
-	
+
 	@Override
 	public UnifyType setTypeParams(TypeParams newTp) {
-		if(newTp.hashCode() == typeParams.hashCode() && newTp.equals(typeParams))
+		if (newTp.hashCode() == typeParams.hashCode() && newTp.equals(typeParams))
 			return this; // reduced the amount of objects created
 		return new ReferenceType(typeName, newTp);
 	}
-	
+
 	@Override
 	public int hashCode() {
 		return hashCode;
 	}
-	
+
 	@Override
 	public boolean equals(Object obj) {
-		if(!(obj instanceof ReferenceType))
+		if (!(obj instanceof ReferenceType))
 			return false;
-		
+
-		if(obj.hashCode() != this.hashCode())
+		if (obj.hashCode() != this.hashCode())
 			return false;
-		
+
 		ReferenceType other = (ReferenceType) obj;
-		
+
-		if(!other.getName().equals(typeName))
+		if (!other.getName().equals(typeName))
 			return false;
 
 		return other.getTypeParams().equals(typeParams);
 	}
-}
+
+	@Override
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		serialized.put("name", this.typeName);
+		serialized.put("params", SerialList.fromMapped(this.typeParams.get(), param -> param.toSerial(keyStorage)));
+		serialized.put("isGenericTypeVar", this.genericTypeVar);
+
+		// create the wrapper and put this as the object
+		var serializedWrapper = super.toSerial(keyStorage);
+		serializedWrapper.put("object", serialized);
+		return serializedWrapper;
+	}
+
+	public static ReferenceType fromSerial(SerialMap data, UnifyContext context) {
+		var name = data.getValue("name").getOf(String.class);
+		var params = data.getList("params").assertListOfMaps().stream().map(
+			paramData -> UnifyType.fromSerial(paramData, context)).toList();
+		var isGenericTypeVar = data.getValue("isGenericTypeVar").getOf(Boolean.class);
+		return new ReferenceType(name, new TypeParams(params), isGenericTypeVar);
+	}
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/model/SuperType.java

@@ -1,6 +1,9 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
-import java.util.HashMap;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
@@ -85,4 +88,26 @@ public final class SuperType extends WildcardType {
 		SuperType other = (SuperType) obj;
 		return other.getSuperedType().equals(wildcardedType);
 	}
+
+	@Override
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		serialized.put("wildcardedType", this.wildcardedType.toSerial(keyStorage));
+		serialized.put("params", SerialList.fromMapped(this.typeParams.get(), param -> param.toSerial(keyStorage)));
+
+		// create the wrapper and put this as the object
+		var serializedWrapper = super.toSerial(keyStorage);
+		serializedWrapper.put("object", serialized);
+		return serializedWrapper;
+	}
+
+	public static SuperType fromSerial(SerialMap data, UnifyContext context) {
+		var params = data.getList("params").assertListOfMaps().stream().map(
+			paramData -> UnifyType.fromSerial(paramData, context)).toList();
+		var superType = new SuperType(
+			UnifyType.fromSerial(data.getMap("wildcardedType"), context)
+		);
+		superType.setTypeParams(new TypeParams(params));
+		return superType;
+	}
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/model/TypeParams.java

@@ -174,9 +174,9 @@ public final class TypeParams implements Iterable<UnifyType>{
 	
 	@Override
 	public String toString() {
-		String res = "";
+		StringBuilder res = new StringBuilder();
 		for(UnifyType t : typeParams)
-			res += t + ",";
+			res.append(t).append(",");
 		return "<" + res.substring(0, res.length()-1) + ">";
 	}
 

src/main/java/de/dhbwstuttgart/typeinference/unify/model/Unifier.java

@@ -50,8 +50,7 @@ public class Unifier implements Function<UnifyType, UnifyType>, Iterable<Entry<P
 		Unifier tempU = new Unifier(source, target);
 		// Every new substitution must be applied to previously added substitutions
 		// otherwise the unifier needs to be applied multiple times to unify two terms
-		for(PlaceholderType pt : substitutions.keySet())
+		substitutions.replaceAll((pt, ut) -> ut.apply(tempU));
-			substitutions.put(pt, substitutions.get(pt).apply(tempU));
 		substitutions.put(source, target);
 	}
 
@@ -93,8 +92,7 @@ public class Unifier implements Function<UnifyType, UnifyType>, Iterable<Entry<P
 		//	}
 		//}
 		if (!(p.getLhsType().equals(newLhs)) || !(p.getRhsType().equals(newRhs))) {//Die Anwendung von this hat was veraendert PL 2018-04-01
-			Set<UnifyPair> suniUnifyPair = new HashSet<>();
+      Set<UnifyPair> suniUnifyPair = new HashSet<>(thisAsPair.getAllSubstitutions());
-			suniUnifyPair.addAll(thisAsPair.getAllSubstitutions());
 			suniUnifyPair.add(thisAsPair);
 			if (p.getLhsType() instanceof PlaceholderType //&& newLhs instanceof PlaceholderType entfernt PL 2018-04-13
 					&& p.getPairOp() == PairOperator.EQUALSDOT) {
@@ -172,13 +170,13 @@ public class Unifier implements Function<UnifyType, UnifyType>, Iterable<Entry<P
 
 	@Override
 	public String toString() {
-		String result = "{ ";
+		StringBuilder result = new StringBuilder("{ ");
 		for(Entry<PlaceholderType, UnifyType> entry : substitutions.entrySet())
-			result += "(" + entry.getKey() + " -> " + entry.getValue() + "), ";
+			result.append("(").append(entry.getKey()).append(" -> ").append(entry.getValue()).append("), ");
 		if(!substitutions.isEmpty())
-			result = result.substring(0, result.length()-2);
+			result = new StringBuilder(result.substring(0, result.length() - 2));
-		result += " }";
+		result.append(" }");
-		return result;
+		return result.toString();
 	}
 
 	@Override

src/main/java/de/dhbwstuttgart/typeinference/unify/model/UnifyPair.java

@@ -1,23 +1,26 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
-import com.google.common.collect.ObjectArrays;
 import de.dhbwstuttgart.parser.SourceLoc;
-import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
-import org.antlr.v4.runtime.Token;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialUUID;
+import de.dhbwstuttgart.typeinference.constraints.IConstraintElement;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 
 /**
  * A pair which contains two types and an operator, e.q. (Integer <. a).
  * @author Florian Steurer
  */
-public class UnifyPair {
+public class UnifyPair implements IConstraintElement, ISerializableData {
 
 	private SourceLoc location;
 
@@ -151,8 +154,7 @@ public class UnifyPair {
 	}
 	
 	public Set<UnifyPair> getAllSubstitutions () {
-		Set<UnifyPair> ret = new HashSet<>();
+    Set<UnifyPair> ret = new HashSet<>(new ArrayList<>(getSubstitution()));
-		ret.addAll(new ArrayList<>(getSubstitution()));
 		if (basePair != null) {
 			ret.addAll(new ArrayList<>(basePair.getAllSubstitutions()));
 		}
@@ -243,16 +245,16 @@ public class UnifyPair {
 	public String toString() {
 		String ret = "";
 		if (lhs instanceof PlaceholderType) {
-			ret = new Integer(((PlaceholderType)lhs).getVariance()).toString() + " "
+			ret = Integer.valueOf(((PlaceholderType)lhs).getVariance()).toString() + " "
 					+ "WC: " + ((PlaceholderType)lhs).isWildcardable()
 					+ ", IT: " + ((PlaceholderType)lhs).isInnerType();
 		}
 		if (rhs instanceof PlaceholderType) {
-			ret = ret + ", " + new Integer(((PlaceholderType)rhs).getVariance()).toString() + " " 
+			ret = ret + ", " + Integer.valueOf(((PlaceholderType)rhs).getVariance()).toString() + " "
 					+ "WC: " + ((PlaceholderType)rhs).isWildcardable()
 					+ ", IT: " + ((PlaceholderType)rhs).isInnerType();
 		}
-		var res =  "(" + lhs + " " + pairOp + " " + rhs + ", " + ret + ")"; //+ ", [" + getfBounded().toString()+ "])";
+		var res =  "(UP: " + lhs + " " + pairOp + " " + rhs + ", " + ret + ")"; //+ ", [" + getfBounded().toString()+ "])";
 		var location = this.getLocation();
 		if (location != null) {
 			res += "@" + location.line() + " in " + location.file();
@@ -269,6 +271,58 @@ public class UnifyPair {
 		return ret;
 	}
 	*/
+	private String serialUUID = null;
+
+	public SerialUUID toSerial(KeyStorage keyStorage) {
+		final String uuid = serialUUID == null ? keyStorage.getIdentifier() : serialUUID;
+		if (serialUUID == null) serialUUID = uuid;
+
+		if (!keyStorage.isAlreadySerialized(uuid)) {
+			SerialMap serialized = new SerialMap();
+			keyStorage.putSerialized(uuid, serialized);
+			serialized.put("lhs", this.lhs.toSerial(keyStorage));
+			serialized.put("rhs", this.rhs.toSerial(keyStorage));
+			serialized.put("op", this.pairOp.toString());
+			serialized.put("basePair", this.basePair == null ? null : this.basePair.toSerial(keyStorage));
+			serialized.put("location", this.location == null ? null : this.location.toSerial(keyStorage));
+			serialized.put("substitution", SerialList.fromMapped(this.substitution, unifyPair -> unifyPair.toSerial(keyStorage)));
+			serialized.put("fBounded", SerialList.fromMapped(this.fBounded, fbounded -> fbounded.toSerial(keyStorage)));
+		}
+		return new SerialUUID(uuid);
+	}
+
+	public static UnifyPair fromSerial(SerialUUID serialUUID, UnifyContext context, KeyStorage keyStorage) {
+		String uuid = serialUUID.uuid;
+		if (!keyStorage.isAlreadyUnserialized(uuid)) {
+			SerialMap data = keyStorage.getSerialized(uuid);
+			SerialMap lhsData = data.getMap("lhs");
+			SerialMap rhsData = data.getMap("rhs");
+			String opData = data.getValue("op").getOf(String.class);
+
+			UnifyPair pair = new UnifyPair(
+				UnifyType.fromSerial(lhsData, context),
+				UnifyType.fromSerial(rhsData, context),
+				PairOperator.fromString(opData)
+			);
+			// put the object into the storage before unserializing basePair recursively
+			keyStorage.putUnserialized(uuid, pair);
+
+			SerialList<SerialUUID> substitutionData = data.getList("substitution").assertListOfUUIDs();
+			SerialList<SerialMap> fBoundedData = data.getList("fBounded").assertListOfMaps();
+			SerialUUID basePairData = data.getUUIDOrNull("basePair");
+			SerialMap locationData = data.getMapOrNull("location");
+
+			pair.substitution = substitutionData.stream().map(substData -> UnifyPair.fromSerial(substData, context, keyStorage)).collect(Collectors.toSet());
+			pair.fBounded = fBoundedData.stream().map(fBoundData -> UnifyType.fromSerial(fBoundData, context)).collect(Collectors.toSet());
+			if (basePairData != null) {
+				pair.basePair = UnifyPair.fromSerial(basePairData, context, keyStorage);
+			}
+			if (locationData != null) {
+				pair.location = SourceLoc.fromSerial(locationData);
+			}
+		}
+		return keyStorage.getUnserialized(uuid, UnifyPair.class);
+	}
 }
 
 

src/main/java/de/dhbwstuttgart/typeinference/unify/model/UnifyType.java

@@ -1,12 +1,14 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialValue;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashMap;
-import java.util.List;
 import java.util.Set;
 
-import de.dhbwstuttgart.syntaxtree.StatementVisitor;
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
 import de.dhbwstuttgart.typeinference.unify.interfaces.UnifyTypeVisitor;
 
@@ -14,7 +16,7 @@ import de.dhbwstuttgart.typeinference.unify.interfaces.UnifyTypeVisitor;
  * Represents a java type.
  * @author Florian Steurer
  */
-public abstract class UnifyType {
+public abstract class UnifyType implements ISerializableData {
 	
 	/**
 	 * The name of the type e.q. "Integer", "? extends Integer" or "List" for (List<T>)
@@ -29,7 +31,7 @@ public abstract class UnifyType {
 	/**
 	 * Creates a new instance
 	 * @param name Name of the type (e.q. List for List<T>, Integer or ? extends Integer)
-	 * @param typeParams Parameters of the type (e.q. <T> for List<T>)
+	 * @param p Parameters of the type (e.q. <T> for List<T>)
 	 */
 	protected UnifyType(String name, TypeParams p) {
 		typeName = name;
@@ -87,20 +89,18 @@ public abstract class UnifyType {
 	
 	@Override
 	public String toString() {
-		String params = "";
+		StringBuilder params = new StringBuilder();
 		if(typeParams.size() != 0) {
 			for(UnifyType param : typeParams)
-				params += param.toString() + ",";
+				params.append(param.toString()).append(",");
-			params = "<" + params.substring(0, params.length()-1) + ">";
+			params = new StringBuilder("<" + params.substring(0, params.length() - 1) + ">");
 		}
 		
 		return typeName + params;
 	}
 
 	public Collection<PlaceholderType> getInvolvedPlaceholderTypes() {
-		ArrayList<PlaceholderType> ret = new ArrayList<>();
+    return new ArrayList<>(typeParams.getInvolvedPlaceholderTypes());
-		ret.addAll(typeParams.getInvolvedPlaceholderTypes());
-		return ret;
 	}
 	
 	public Boolean wrongWildcard() {//default
@@ -114,7 +114,40 @@ public abstract class UnifyType {
 
 	@Override
 	public boolean equals(Object obj) {
-		if(obj == null)return false;
+		if(obj == null) return false;
 		return this.toString().equals(obj.toString());
 	}
-}
+
+	public SerialMap toSerial(KeyStorage keyStorage) {
+		SerialMap serialized = new SerialMap();
+		String type = switch (this) {
+			case FunInterfaceType _ -> "funi";
+			case ReferenceType _ -> "ref";
+      case ExtendsType _ -> "ext";
+      case SuperType _ -> "sup";
+      case FunNType _ -> "funn";
+      case PlaceholderType _ -> "tph";
+      default -> throw new RuntimeException("No type defined for UnifyType of class " + this.getClass().getName());
+    };
+
+    serialized.put("type", type);
+		// we only insert null for the object and expect the child classes to call this and override the value with themselves
+		serialized.put("object", SerialValue.NULL);
+		return serialized;
+	}
+
+	public static UnifyType fromSerial(SerialMap data, UnifyContext context) {
+		var type = data.getValue("type").getOf(String.class);
+		var object = data.getMap("object");
+
+		return switch (type) {
+			case "funi" -> FunInterfaceType.fromSerial(object, context);
+			case "ref" -> ReferenceType.fromSerial(object, context);
+			case "ext" -> ExtendsType.fromSerial(object, context);
+			case "sup" -> SuperType.fromSerial(object, context);
+			case "funn" -> FunNType.fromSerial(object, context);
+			case "tph" -> PlaceholderType.fromSerial(object, context);
+			default -> throw new RuntimeException("Could not unserialize class of unhandled type " + type);
+		};
+	}
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/model/WildcardType.java

@@ -1,5 +1,6 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
 import java.util.ArrayList;
 import java.util.Collection;
 
@@ -7,7 +8,7 @@ import java.util.Collection;
  * A wildcard type that is either a ExtendsType or a SuperType.
  * @author Florian Steurer
  */
-public abstract class WildcardType extends UnifyType {
+public abstract class WildcardType extends UnifyType implements ISerializableData {
 	
 	/**
 	 * The wildcarded type, e.q. Integer for ? extends Integer. Never a wildcard type itself.
@@ -65,8 +66,7 @@ public abstract class WildcardType extends UnifyType {
 
 	@Override
 	public Collection<PlaceholderType> getInvolvedPlaceholderTypes() {
-		ArrayList<PlaceholderType> ret = new ArrayList<>();
+    ArrayList<PlaceholderType> ret = new ArrayList<>(wildcardedType.getInvolvedPlaceholderTypes());
-		ret.addAll(wildcardedType.getInvolvedPlaceholderTypes());
 		return ret;
 	}
 }

src/main/java/de/dhbwstuttgart/util/Logger.java

@@ -0,0 +1,9 @@
+package de.dhbwstuttgart.util;
+
+public class Logger {
+
+  public static void print(String s) {
+    System.out.println(s);
+  }
+
+}

src/main/java/de/dhbwstuttgart/util/Pair.java

@@ -3,37 +3,26 @@ package de.dhbwstuttgart.util;
 import java.util.Objects;
 import java.util.Optional;
 
-public class Pair<T, T1> {
+public class Pair<T, T1> extends Tuple<T, T1> {
-    private final T key;
-    private final T1 value;
 
-    public Pair(T a, T1 b) {
+  public Pair(T a, T1 b) {
-        this.value = b;
+    super(a, b);
-        this.key = a;
+  }
-    }
 
-    public Optional<T1> getValue() {
+  public Optional<T1> getValue() {
-        return Optional.of(value);
+    return Optional.of(second);
-    }
+  }
 
-    public T getKey() {
+  public T getKey() {
-        return key;
+    return first;
-    }
+  }
-    
-    public String toString() {
-    	return "(" + key.toString() + "," + value.toString() + ")\n";
-    }
 
-    @Override
+  @Override
-    public boolean equals(Object o) {
+  public boolean equals(Object o) {
-        if (this == o) return true;
+    if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+    if (o == null || getClass() != o.getClass()) return false;
-        Pair<?, ?> pair = (Pair<?, ?>) o;
+    Pair<?, ?> pair = (Pair<?, ?>) o;
-        return Objects.equals(key, pair.key) && Objects.equals(value, pair.value);
+    return Objects.equals(first, pair.first) && Objects.equals(second, pair.second);
-    }
+  }
 
-    @Override
-    public int hashCode() {
-        return Objects.hash(key, value);
-    }
 }

src/main/java/de/dhbwstuttgart/util/Tuple.java

@@ -0,0 +1,38 @@
+package de.dhbwstuttgart.util;
+
+import java.util.Objects;
+
+public class Tuple<T1, T2> {
+    protected final T1 first;
+    protected final T2 second;
+
+    public Tuple(T1 a, T2 b) {
+        this.second = b;
+        this.first = a;
+    }
+
+    public T1 getFirst() {
+        return first;
+    }
+
+    public T2 getSecond() {
+        return second;
+    }
+
+    public String toString() {
+    	return "(" + first.toString() + "," + second.toString() + ")\n";
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Tuple<?, ?> pair = (Tuple<?, ?>) o;
+        return Objects.equals(first, pair.first) && Objects.equals(second, pair.second);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(first, second);
+    }
+}

src/test/java/finiteClosure/SuperInterfacesTest.java

@@ -1,8 +1,10 @@
 package finiteClosure;
 
+import de.dhbwstuttgart.core.JavaTXCompiler;
 import de.dhbwstuttgart.parser.SyntaxTreeGenerator.FCGenerator;
 import de.dhbwstuttgart.syntaxtree.ClassOrInterface;
 import de.dhbwstuttgart.syntaxtree.factory.ASTFactory;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -14,14 +16,14 @@ public class SuperInterfacesTest {
     public void test() throws ClassNotFoundException {
         Collection<ClassOrInterface> classes = new ArrayList<>();
         classes.add(ASTFactory.createClass(TestClass.class));
-        System.out.println(FCGenerator.toFC(classes, ClassLoader.getSystemClassLoader()));
+        System.out.println(FCGenerator.toFC(classes, ClassLoader.getSystemClassLoader(), JavaTXCompiler.defaultClientPlaceholderRegistry));
     }
 
     @Test
     public void testGeneric() throws ClassNotFoundException {
         Collection<ClassOrInterface> classes = new ArrayList<>();
         classes.add(ASTFactory.createClass(TestClassGeneric.class));
-        System.out.println(FCGenerator.toFC(classes, ClassLoader.getSystemClassLoader()));
+        System.out.println(FCGenerator.toFC(classes, ClassLoader.getSystemClassLoader(), JavaTXCompiler.defaultClientPlaceholderRegistry));
     }
 }
 

src/test/java/server/PacketExampleData.java

@@ -0,0 +1,101 @@
+package server;
+
+import de.dhbwstuttgart.parser.SourceLoc;
+import de.dhbwstuttgart.typeinference.constraints.Constraint;
+import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.UnifyResultModel;
+import de.dhbwstuttgart.typeinference.unify.UnifyTaskModel;
+import de.dhbwstuttgart.typeinference.unify.model.ExtendsType;
+import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.FunInterfaceType;
+import de.dhbwstuttgart.typeinference.unify.model.FunNType;
+import de.dhbwstuttgart.typeinference.unify.model.PairOperator;
+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;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyType;
+import java.io.Writer;
+import java.util.HashSet;
+import java.util.List;
+import java.util.concurrent.ForkJoinPool;
+
+class PacketExampleData {
+
+  static ConstraintSet<UnifyPair> getExampleUnifyPairConstraintSet(
+    UnifyContext unifyContext, String packagePath, int numUndCons, int numOderCons
+  ) {
+    var constraintSet = new ConstraintSet<UnifyPair>();
+    for (int i = 0; i < numUndCons; i++) {
+      constraintSet.addUndConstraint(
+        getExampleUnifyPair(unifyContext, packagePath+"undCons.")
+      );
+    }
+    for (int i = 0; i < numOderCons; i++) {
+      var oderConstraint = new HashSet<Constraint<UnifyPair>>();
+      getExampleUnifyPairConstraint(unifyContext, packagePath+"oderCons.", i == 0);
+      constraintSet.addOderConstraint(oderConstraint);
+    }
+    return constraintSet;
+  }
+
+  static Constraint<UnifyPair> getExampleUnifyPairConstraint(UnifyContext unifyContext, String packagePath, boolean withExtends) {
+    return new Constraint<>(
+      !withExtends, true,
+      withExtends ? getExampleUnifyPairConstraint(unifyContext, packagePath+"extendConstraint.", false) : null,
+      withExtends ? new HashSet<>(List.of(
+        getExampleUnifyPair(unifyContext, packagePath+"methodSignatureConstraint.zero."),
+        getExampleUnifyPair(unifyContext, packagePath+"methodSignatureConstraint.one.")
+      )) : null
+    );
+  }
+
+  static UnifyPair getExampleUnifyPair(UnifyContext unifyContext, String packagePath) {
+    return new UnifyPair(
+      new ReferenceType(packagePath + "something", false),
+      new ExtendsType(
+        new SuperType(
+          new FunInterfaceType("lambda" + unifyContext.placeholderRegistry().generateFreshPlaceholderName(),
+            new TypeParams(),
+            List.of( // intfArgTypes
+              FunNType.getFunNType(new TypeParams(
+                List.of(
+                  PlaceholderType.freshPlaceholder(unifyContext.placeholderRegistry()),
+                  PlaceholderType.freshPlaceholder(unifyContext.placeholderRegistry())
+                )
+              ))
+            ),
+            PlaceholderType.freshPlaceholder(unifyContext.placeholderRegistry()), // intfReturnType
+            List.of( // generics
+              "ZA",
+              "ZB",
+              unifyContext.placeholderRegistry().generateFreshPlaceholderName()
+            )
+          )
+        )
+      ),
+      PairOperator.SMALLERDOT,
+      new SourceLoc("test.jav", 10)
+    );
+  }
+
+  static UnifyContext createTestContext() {
+    var placeholderRegistry = new PlaceholderRegistry();
+    var nullWriter = Writer.nullWriter();
+    return new UnifyContext(nullWriter, false, true,
+      new UnifyResultModel(
+        new ConstraintSet<>(),
+        new FiniteClosure(
+          new HashSet<>(),
+          nullWriter,
+          placeholderRegistry)),
+      new UnifyTaskModel(),
+      ForkJoinPool.commonPool(),
+      placeholderRegistry
+    );
+  }
+
+}

src/test/java/server/PacketTest.java

@@ -0,0 +1,110 @@
+package server;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import de.dhbwstuttgart.environment.ByteArrayClassLoader;
+import de.dhbwstuttgart.parser.SourceLoc;
+import de.dhbwstuttgart.server.packet.DebugPacket;
+import de.dhbwstuttgart.server.packet.IPacket;
+import de.dhbwstuttgart.server.packet.InvalidPacket;
+import de.dhbwstuttgart.server.packet.PacketContainer;
+import de.dhbwstuttgart.server.packet.dataContainers.ISerializableData;
+import de.dhbwstuttgart.server.packet.dataContainers.KeyStorage;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.ISerialNode;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialList;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialMap;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialUUID;
+import de.dhbwstuttgart.server.packet.dataContainers.serialized.SerialValue;
+import de.dhbwstuttgart.typeinference.constraints.Constraint;
+import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.UnifyResultModel;
+import de.dhbwstuttgart.typeinference.unify.UnifyTaskModel;
+import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import java.io.Writer;
+import java.util.HashSet;
+import java.util.concurrent.ForkJoinPool;
+import java.util.function.BiFunction;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class PacketTest {
+
+  @Test
+  public void serializeUnifyPair() throws JsonProcessingException {
+    UnifyContext unifyContext = PacketExampleData.createTestContext();
+
+    var original = PacketExampleData.getExampleUnifyPair(unifyContext, "de.test.");
+    var reconstruction = serializeAndDeserialize(original, unifyContext,
+      (o,k) -> UnifyPair.fromSerial((SerialUUID) o,unifyContext,k));
+
+    assertEquals(original.getClass(), reconstruction.getClass());
+    assertEquals(original.toString(), reconstruction.toString());
+    assertEquals(original, reconstruction);
+  }
+
+  @Test
+  public void serializeUnifyPairConstraint() throws JsonProcessingException {
+    UnifyContext unifyContext = PacketExampleData.createTestContext();
+
+    var original = PacketExampleData.getExampleUnifyPairConstraint(unifyContext, "de.", true);
+    var reconstruction = serializeAndDeserialize(original, unifyContext,
+      (o,k) -> Constraint.fromSerial((SerialUUID) o, unifyContext, UnifyPair.class, k));
+
+    assertEquals(original.getClass(), reconstruction.getClass());
+    assertEquals(original.toString(), reconstruction.toString());
+    assertEquals(original, reconstruction);
+  }
+
+  @Test
+  public void serializeUnifyPairConstraintSet() throws JsonProcessingException {
+    UnifyContext unifyContext = PacketExampleData.createTestContext();
+
+    var original = PacketExampleData.getExampleUnifyPairConstraintSet(unifyContext, "de.", 1, 2);
+    var reconstruction = serializeAndDeserialize(original, unifyContext,
+      (o,k) -> ConstraintSet.fromSerial((SerialMap) o, unifyContext, UnifyPair.class, k));
+
+    assertEquals(original.getClass(), reconstruction.getClass());
+    assertEquals(original.toString(), reconstruction.toString());
+    assertEquals(original, reconstruction);
+  }
+
+
+  /**
+   *  Helper method for serializing an ISerialNode into JSON, then deserializing it
+   */
+  private <T extends ISerialNode, R extends ISerializableData> R serializeAndDeserialize(
+    ISerializableData object, UnifyContext unifyContext, BiFunction<T, KeyStorage, R> fromSerial
+  ) throws JsonProcessingException {
+
+    DebugPacket packet = new DebugPacket();
+    KeyStorage keyStorage = new KeyStorage();
+    var serializedObject = object.toSerial(keyStorage);
+    if (serializedObject instanceof SerialUUID sObject)     packet.a1 = sObject;
+    if (serializedObject instanceof SerialMap sObject)      packet.b1 = sObject;
+    if (serializedObject instanceof SerialList<?> sObject)  packet.c1 = sObject;
+    if (serializedObject instanceof SerialValue<?> sObject) packet.d1 = sObject;
+    packet.b2 = keyStorage.toSerial(keyStorage);
+
+    DebugPacket reconstructedPacket = serializeAndDeserializePacket(packet);
+
+    KeyStorage reconstructedKeyStorage = KeyStorage.fromSerial(reconstructedPacket.b2, unifyContext);
+    ISerialNode reconstructedData = null;
+    if (serializedObject instanceof SerialUUID)     reconstructedData = packet.a1;
+    if (serializedObject instanceof SerialMap)      reconstructedData = packet.b1;
+    if (serializedObject instanceof SerialList<?>)  reconstructedData = packet.c1;
+    if (serializedObject instanceof SerialValue<?>) reconstructedData = packet.d1;
+
+    assertNotNull(reconstructedData);
+    return fromSerial.apply( (T) reconstructedData, reconstructedKeyStorage);
+  }
+
+  private <T extends IPacket> T serializeAndDeserializePacket(T packet) throws JsonProcessingException {
+    String json = PacketContainer.serialize(packet);
+    IPacket reconstructedPacket = PacketContainer.deserialize(json);
+    assertNotNull(reconstructedPacket);
+    assertSame(packet.getClass(), reconstructedPacket.getClass());
+    return (T) reconstructedPacket;
+  }
+}

src/test/java/server/ServerTest.java

@@ -0,0 +1,141 @@
+package server;
+
+import de.dhbwstuttgart.core.JavaTXCompiler;
+import de.dhbwstuttgart.core.JavaTXServer;
+import de.dhbwstuttgart.environment.CompilationEnvironment;
+import de.dhbwstuttgart.server.SocketClient;
+import de.dhbwstuttgart.syntaxtree.ClassOrInterface;
+import de.dhbwstuttgart.syntaxtree.factory.ASTFactory;
+import de.dhbwstuttgart.syntaxtree.factory.UnifyTypeFactory;
+import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
+import de.dhbwstuttgart.typeinference.constraints.Pair;
+import de.dhbwstuttgart.typeinference.result.ResultSet;
+import de.dhbwstuttgart.typeinference.unify.PlaceholderRegistry;
+import de.dhbwstuttgart.typeinference.unify.TypeUnify;
+import de.dhbwstuttgart.typeinference.unify.UnifyContext;
+import de.dhbwstuttgart.typeinference.unify.UnifyResultListenerImpl;
+import de.dhbwstuttgart.typeinference.unify.UnifyResultModel;
+import de.dhbwstuttgart.typeinference.unify.UnifyTaskModel;
+import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyType;
+import java.io.File;
+import java.io.IOException;
+import java.io.Writer;
+import java.nio.file.Path;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+import org.junit.Ignore;
+import org.junit.Test;
+import targetast.TestCodegen;
+import static org.junit.Assert.*;
+
+@Ignore("Server tests create huge overhead, so they are ignored until required")
+public class ServerTest {
+
+  @Test
+  public void checkServer_Scalar() throws IOException, ClassNotFoundException {
+    compareLocalAndServerResult("Scalar.jav");
+  }
+
+  @Test
+  public void checkServer_Matrix() throws IOException, ClassNotFoundException {
+    compareLocalAndServerResult("Matrix.jav");
+  }
+
+  protected void compareLocalAndServerResult(final String filename) throws IOException, ClassNotFoundException {
+    File file = Path.of(TestCodegen.path.toString(), filename).toFile();
+
+    // get information from compiler
+    JavaTXCompiler compiler = new JavaTXCompiler(List.of(file));
+
+    // NOW: simulate the call to method typeInference. Once via server and once locally
+    // if everything works, they should neither interfere with each other, nor differ in their result
+
+    // get the values from the compiler
+    PlaceholderRegistry placeholderRegistry = JavaTXCompiler.defaultClientPlaceholderRegistry; //new PlaceholderRegistry();
+    ConstraintSet<Pair> cons = compiler.getConstraints(file);
+    ConstraintSet<UnifyPair> unifyCons = UnifyTypeFactory.convert(compiler, cons, placeholderRegistry);
+    unifyCons = unifyCons.map(ServerTest::distributeInnerVars);
+
+    FiniteClosure finiteClosure = UnifyTypeFactory.generateFC(
+      ServerTest.getAllClasses(compiler, file).stream().toList(),
+      Writer.nullWriter(),
+      compiler.classLoader,
+      compiler,
+      placeholderRegistry
+    );
+    UnifyTaskModel usedTasks = new UnifyTaskModel();
+
+
+
+    // create the server
+    JavaTXServer server = new JavaTXServer(5000);
+    try (ExecutorService executor = Executors.newSingleThreadExecutor()) {
+      // run the server in a separate thread
+      executor.submit(server::listen);
+    }
+
+    // run the unification on the server
+    PlaceholderRegistry prCopy = JavaTXCompiler.defaultClientPlaceholderRegistry.deepClone();
+    UnifyResultModel urm = new UnifyResultModel(cons, finiteClosure);
+    UnifyContext context = new UnifyContext(Writer.nullWriter(), false, true, urm, usedTasks, prCopy);
+    SocketClient socketClient = new SocketClient("ws://localhost:5000");
+    List<ResultSet> serverResult = socketClient.execute(finiteClosure, cons, unifyCons, context);
+
+    // close the server
+    server.forceStop();
+
+    // run the unification on the client (do this second, because it changes the initial placeholder registry)
+    UnifyResultListenerImpl li = new UnifyResultListenerImpl();
+    urm.addUnifyResultListener(li);
+    TypeUnify.unifyParallel(unifyCons.getUndConstraints(), unifyCons.getOderConstraints(), finiteClosure, context);
+    List<ResultSet> clientResult = li.getResults();
+
+
+    // create the bytecode from both results
+    var sf = compiler.sourceFiles.get(file);
+    var serverBytecode = compiler.generateBytecode(sf, serverResult);
+    var localBytecode = compiler.generateBytecode(sf, clientResult);
+
+    // test if the generated code is the same
+    for (var serverEntry : serverBytecode.entrySet()) {
+      var serverBytes = serverEntry.getValue();
+      var localBytes = localBytecode.get(serverEntry.getKey());
+      assertArrayEquals(serverBytes, localBytes);
+    }
+  }
+
+
+  protected static UnifyPair distributeInnerVars(UnifyPair x) {
+    UnifyType lhs, rhs;
+    if (((lhs = x.getLhsType()) instanceof PlaceholderType) && ((rhs = x.getRhsType()) instanceof PlaceholderType) && (((PlaceholderType) lhs).isInnerType() || ((PlaceholderType) rhs).isInnerType())) {
+      ((PlaceholderType) lhs).setInnerType(true);
+      ((PlaceholderType) rhs).setInnerType(true);
+    }
+    return x;
+  }
+
+  protected static Set<ClassOrInterface> getAllClasses(JavaTXCompiler compiler, File file)
+    throws ClassNotFoundException, IOException
+  {
+    var sf = compiler.sourceFiles.get(file);
+    Set<ClassOrInterface> allClasses = new HashSet<>();
+    allClasses.addAll(compiler.getAvailableClasses(sf));
+    allClasses.addAll(sf.getClasses());
+    var newClasses = CompilationEnvironment.loadDefaultPackageClasses(sf.getPkgName(), file, compiler).stream().map(ASTFactory::createClass).collect(Collectors.toSet());
+    for (var clazz : newClasses) {
+      // Don't load classes that get recompiled
+      if (sf.getClasses().stream().anyMatch(nf -> nf.getClassName().equals(clazz.getClassName())))
+        continue;
+      if (allClasses.stream().noneMatch(old -> old.getClassName().equals(clazz.getClassName())))
+        allClasses.add(clazz);
+    }
+    return allClasses;
+  }
+}