diff --git a/Source/.idea/libraries/asm_9_7.xml b/Source/.idea/libraries/asm_9_7.xml
index 1d812dc..2233f59 100644
--- a/Source/.idea/libraries/asm_9_7.xml
+++ b/Source/.idea/libraries/asm_9_7.xml
@@ -2,6 +2,7 @@
   <library name="asm-9.7">
     <CLASSES>
       <root url="jar://$PROJECT_DIR$/../Lib/asm-9.7.jar!/" />
+      <root url="jar://$PROJECT_DIR$/../../../antlr-4.13.1-complete.jar!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />
diff --git a/Source/.idea/misc.xml b/Source/.idea/misc.xml
index e0844bc..ceb7609 100644
--- a/Source/.idea/misc.xml
+++ b/Source/.idea/misc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="11" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_16" project-jdk-name="openjdk-22" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/Source/Compiler.java b/Source/Compiler.java
index 8ba724a..d993d97 100644
--- a/Source/Compiler.java
+++ b/Source/Compiler.java
@@ -2,7 +2,17 @@ import abstractSyntaxTree.Class.FieldDecl;
 import abstractSyntaxTree.Class.MethodDecl;
 import abstractSyntaxTree.Class.RefType;
 import abstractSyntaxTree.Program;
+import gen.DecafLexer;
+import gen.DecafParser;
+import org.antlr.v4.runtime.CharStream;
+import org.antlr.v4.runtime.CharStreams;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.Token;
+import org.antlr.v4.runtime.tree.ParseTree;
 
+import java.io.CharArrayReader;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -11,6 +21,36 @@ public class Compiler {
     public static void main(String[] args) throws Exception{
 
         // get file
+//        String filePath = "EmptyClass.java";
+//        String content = new String(Files.readAllBytes(Paths.get(filePath)));
+//        CharArrayReader charStream = new CharArrayReader(content.toCharArray());
+
+        CharStream codeCharStream = CharStreams.fromString("class Example { }");
+        DecafLexer lexer = new DecafLexer(codeCharStream);
+        CommonTokenStream tokens = new CommonTokenStream(lexer);
+
+        System.out.println("--- print tokens ---");
+        tokens.fill();
+
+        List<Token> tokenList = tokens.getTokens();
+
+        StringBuilder stringBuilder = new StringBuilder();
+        for (Token token : tokenList) {
+            stringBuilder.append(token.toString()).append(" ");
+        }
+        String readableTokens = stringBuilder.toString().trim();
+
+        System.out.println(readableTokens);
+
+
+        DecafParser parser = new DecafParser(tokens);
+
+        ParseTree tree = parser.program();
+
+        System.out.println("--- print tree ---");
+        System.out.println(tree);
+
+
 
         Program abstractSyntaxTree = new Program(new ArrayList<>());
         List<FieldDecl> emptyFieldDecl = new ArrayList<>();
diff --git a/Source/gen/DecafBaseListener.java b/Source/gen/DecafBaseListener.java
index 0821290..59f157f 100644
--- a/Source/gen/DecafBaseListener.java
+++ b/Source/gen/DecafBaseListener.java
@@ -1,4 +1,4 @@
-// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
+package gen;// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
 
 import org.antlr.v4.runtime.ParserRuleContext;
 import org.antlr.v4.runtime.tree.ErrorNode;
diff --git a/Source/gen/DecafBaseVisitor.java b/Source/gen/DecafBaseVisitor.java
index b996318..9bd240e 100644
--- a/Source/gen/DecafBaseVisitor.java
+++ b/Source/gen/DecafBaseVisitor.java
@@ -1,4 +1,4 @@
-// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
+package gen;// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
 import org.antlr.v4.runtime.tree.AbstractParseTreeVisitor;
 
 /**
diff --git a/Source/gen/DecafLexer.java b/Source/gen/DecafLexer.java
index 71d203e..1448a7c 100644
--- a/Source/gen/DecafLexer.java
+++ b/Source/gen/DecafLexer.java
@@ -1,4 +1,4 @@
-// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
+package gen;// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
 import org.antlr.v4.runtime.Lexer;
 import org.antlr.v4.runtime.CharStream;
 import org.antlr.v4.runtime.Token;
diff --git a/Source/gen/DecafListener.java b/Source/gen/DecafListener.java
index dac8933..4e2702f 100644
--- a/Source/gen/DecafListener.java
+++ b/Source/gen/DecafListener.java
@@ -1,4 +1,4 @@
-// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
+package gen;// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
 import org.antlr.v4.runtime.tree.ParseTreeListener;
 
 /**
diff --git a/Source/gen/DecafParser.java b/Source/gen/DecafParser.java
index f9227d4..f46dc11 100644
--- a/Source/gen/DecafParser.java
+++ b/Source/gen/DecafParser.java
@@ -1,4 +1,4 @@
-// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
+package gen;// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
 import org.antlr.v4.runtime.atn.*;
 import org.antlr.v4.runtime.dfa.DFA;
 import org.antlr.v4.runtime.*;
diff --git a/Source/gen/DecafVisitor.java b/Source/gen/DecafVisitor.java
index 68ee110..e9a524c 100644
--- a/Source/gen/DecafVisitor.java
+++ b/Source/gen/DecafVisitor.java
@@ -1,4 +1,4 @@
-// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
+package gen;// Generated from C:/Users/dh10krj/OneDrive - Durr Group/Dokumente/S4/Compilerbau/projekt/NichtHaskell/Source/Decaf.g4 by ANTLR 4.13.1
 import org.antlr.v4.runtime.tree.ParseTreeVisitor;
 
 /**