GenASM: Make GenASM quietly rewrite a user's function if it's called main.

We generate our own main function that executes the user's specified expression at the end of his file. This auto generated function has to be called "main" in order for it to be executed on startup. If the user chooses to call one of his own functions "main" our auto generated function would collide with the user's function. That's why we quietly rewrite the user's function to "main_by_user". This way we prevent a collision.

Note for the future: We should change our Syntax to allow for no expression as the last definition of a file. This way the user can choose if a particular source file needs to contain a main function or not (just like c does it). This is also one of the requirements for modules to work.

.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/compiler.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CompilerConfiguration">
+    <annotationProcessing>
+      <profile name="Maven default annotation processors profile" enabled="true">
+        <sourceOutputDir name="target/generated-sources/annotations" />
+        <sourceTestOutputDir name="target/generated-test-sources/test-annotations" />
+        <outputRelativeToContentRoot value="true" />
+        <module name="klang" />
+      </profile>
+    </annotationProcessing>
+    <bytecodeTargetLevel>
+      <module name="klang" target="11" />
+    </bytecodeTargetLevel>
+  </component>
+</project>

.idea/encodings.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding">
+    <file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/target/generated-sources/antlr4" charset="UTF-8" />
+  </component>
+</project>

.idea/jarRepositories.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="RemoteRepositoriesConfiguration">
+    <remote-repository>
+      <option name="id" value="central" />
+      <option name="name" value="Central Repository" />
+      <option name="url" value="https://repo.maven.apache.org/maven2" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="central" />
+      <option name="name" value="Maven Central repository" />
+      <option name="url" value="https://repo1.maven.org/maven2" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="jboss.community" />
+      <option name="name" value="JBoss Community repository" />
+      <option name="url" value="https://repository.jboss.org/nexus/content/repositories/public/" />
+    </remote-repository>
+  </component>
+</project>

.idea/libraries/Maven__org_antlr_antlr4_runtime_4_7_2.xml

@@ -0,0 +1,13 @@
+<component name="libraryTable">
+  <library name="Maven: org.antlr:antlr4-runtime:4.7.2">
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.7.2/antlr4-runtime-4.7.2.jar!/" />
+    </CLASSES>
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.7.2/antlr4-runtime-4.7.2-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.7.2/antlr4-runtime-4.7.2-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>

.idea/libraries/Maven__org_apiguardian_apiguardian_api_1_1_0.xml

@@ -0,0 +1,13 @@
+<component name="libraryTable">
+  <library name="Maven: org.apiguardian:apiguardian-api:1.1.0">
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/" />
+    </CLASSES>
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>

.idea/libraries/Maven__org_junit_jupiter_junit_jupiter_api_5_6_0.xml

@@ -0,0 +1,13 @@
+<component name="libraryTable">
+  <library name="Maven: org.junit.jupiter:junit-jupiter-api:5.6.0">
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.6.0/junit-jupiter-api-5.6.0.jar!/" />
+    </CLASSES>
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.6.0/junit-jupiter-api-5.6.0-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.6.0/junit-jupiter-api-5.6.0-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>

.idea/libraries/Maven__org_junit_jupiter_junit_jupiter_engine_5_6_0.xml

@@ -0,0 +1,13 @@
+<component name="libraryTable">
+  <library name="Maven: org.junit.jupiter:junit-jupiter-engine:5.6.0">
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-engine/5.6.0/junit-jupiter-engine-5.6.0.jar!/" />
+    </CLASSES>
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-engine/5.6.0/junit-jupiter-engine-5.6.0-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-engine/5.6.0/junit-jupiter-engine-5.6.0-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>

.idea/libraries/Maven__org_junit_platform_junit_platform_commons_1_6_0.xml

@@ -0,0 +1,13 @@
+<component name="libraryTable">
+  <library name="Maven: org.junit.platform:junit-platform-commons:1.6.0">
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.6.0/junit-platform-commons-1.6.0.jar!/" />
+    </CLASSES>
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.6.0/junit-platform-commons-1.6.0-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.6.0/junit-platform-commons-1.6.0-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>

.idea/libraries/Maven__org_junit_platform_junit_platform_engine_1_6_0.xml

@@ -0,0 +1,13 @@
+<component name="libraryTable">
+  <library name="Maven: org.junit.platform:junit-platform-engine:1.6.0">
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.6.0/junit-platform-engine-1.6.0.jar!/" />
+    </CLASSES>
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.6.0/junit-platform-engine-1.6.0-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.6.0/junit-platform-engine-1.6.0-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>

.idea/libraries/Maven__org_opentest4j_opentest4j_1_2_0.xml

@@ -0,0 +1,13 @@
+<component name="libraryTable">
+  <library name="Maven: org.opentest4j:opentest4j:1.2.0">
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+    </CLASSES>
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>

.idea/misc.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ANTLRGenerationPreferences">
+    <option name="perGrammarGenerationSettings">
+      <list>
+        <PerGrammarGenerationSettings>
+          <option name="fileName" value="$PROJECT_DIR$/src/main/antlr4/de/hsrm/compiler/Klang/Klang.g4" />
+          <option name="outputDir" value="" />
+          <option name="libDir" value="" />
+          <option name="encoding" value="" />
+          <option name="pkg" value="" />
+          <option name="language" value="" />
+          <option name="generateVisitor" value="true" />
+        </PerGrammarGenerationSettings>
+      </list>
+    </option>
+  </component>
+  <component name="MavenProjectsManager">
+    <option name="originalFiles">
+      <list>
+        <option value="$PROJECT_DIR$/pom.xml" />
+      </list>
+    </option>
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="corretto-17" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/classes" />
+  </component>
+</project>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/klang.iml" filepath="$PROJECT_DIR$/klang.iml" />
+    </modules>
+  </component>
+</project>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>

klang.iml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_11">
+    <output url="file://$MODULE_DIR$/target/classes" />
+    <output-test url="file://$MODULE_DIR$/target/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/target/generated-sources/antlr4" isTestSource="false" generated="true" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="Maven: org.antlr:antlr4-runtime:4.7.2" level="project" />
+    <orderEntry type="library" name="Maven: org.junit.jupiter:junit-jupiter-api:5.6.0" level="project" />
+    <orderEntry type="library" name="Maven: org.apiguardian:apiguardian-api:1.1.0" level="project" />
+    <orderEntry type="library" name="Maven: org.opentest4j:opentest4j:1.2.0" level="project" />
+    <orderEntry type="library" name="Maven: org.junit.platform:junit-platform-commons:1.6.0" level="project" />
+    <orderEntry type="library" name="Maven: org.junit.jupiter:junit-jupiter-engine:5.6.0" level="project" />
+    <orderEntry type="library" name="Maven: org.junit.platform:junit-platform-engine:1.6.0" level="project" />
+  </component>
+</module>

pom.xml

@@ -72,6 +72,11 @@
           <descriptorRefs>
             <descriptorRef>jar-with-dependencies</descriptorRef>
           </descriptorRefs>
+          <archive>
+            <manifest>
+              <mainClass>de.hsrm.compiler.Klang.Klang</mainClass>
+            </manifest>
+          </archive>
         </configuration>
         <executions>
           <execution>

src/main/antlr4/de/hsrm/compiler/Klang/Klang.g4

@@ -5,7 +5,11 @@ parse
   ;
 
 program
-  : (functionDef | structDef)* expression SCOL
+  : (functionDef | structDef | enumDef)* expression SCOL
+  ;
+
+enumDef
+  : ENUM enumName=IDENT OBRK (IDENT (COMMA IDENT)*)+ CBRK
   ;
 
 structDef
@@ -78,7 +82,7 @@ destroy_statement
 
 expression
   : atom #atomExpression
-  | IDENT (PERIOD IDENT)+ #structFieldAccessExpression
+  | IDENT (PERIOD IDENT)+ #memberAccessExpression
   | OPAR expression CPAR #parenthesisExpression
   | lhs=expression MUL rhs=expression #multiplicationExpression
   | lhs=expression DIV rhs=expression #divisionExpression
@@ -143,6 +147,7 @@ forLoop
 IF: 'if';
 ELSE: 'else';
 FUNC: 'function';
+ENUM: 'enum';
 STRUCT: 'struct';
 RETURN: 'return';
 LET: 'let';

src/main/java/de/hsrm/compiler/Klang/ContextAnalysis.java

@@ -1,9 +1,5 @@
 package de.hsrm.compiler.Klang;
 
-import java.util.Map;
-import java.util.HashMap;
-
-import de.hsrm.compiler.Klang.helper.FunctionInformation;
 import de.hsrm.compiler.Klang.helper.Helper;
 import de.hsrm.compiler.Klang.nodes.*;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
@@ -13,10 +9,13 @@ import de.hsrm.compiler.Klang.nodes.loops.WhileLoop;
 import de.hsrm.compiler.Klang.nodes.statements.*;
 import de.hsrm.compiler.Klang.types.Type;
 
+import java.util.*;
+
 public class ContextAnalysis extends KlangBaseVisitor<Node> {
   Map<String, VariableDeclaration> vars = new HashMap<>();
-  Map<String, FunctionInformation> funcs;
+  Map<String, FunctionDefinition> functionDefs;
-  Map<String, StructDefinition> structs;
+  Map<String, StructDefinition> structDefs;
+  Map<String, EnumDefinition> enumDefs;
   Type currentDeclaredReturnType;
   String currentFunctionDefinitionName;
 
@@ -27,25 +26,35 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     }
   }
 
-  public ContextAnalysis(Map<String, FunctionInformation> funcs, Map<String, StructDefinition> structs) {
+  public ContextAnalysis(
-    this.funcs = funcs;
+          Map<String, FunctionDefinition> functionDefs,
-    this.structs = structs;
+          Map<String, StructDefinition> structDefs,
+          Map<String, EnumDefinition> enumDefs
+  ) {
+    this.functionDefs = functionDefs;
+    this.structDefs = structDefs;
+    this.enumDefs = enumDefs;
   }
 
   @Override
   public Node visitProgram(KlangParser.ProgramContext ctx) {
-    FunctionDefinition[] funcs = new FunctionDefinition[ctx.functionDef().size()];
+    var typeCheckedFunctionDefs = new FunctionDefinition[ctx.functionDef().size()];
+    var typeCheckedStructDefs = new HashMap<String, StructDefinition>();
 
     for (int i = 0; i < ctx.functionDef().size(); i++) {
-      funcs[i] = (FunctionDefinition) this.visit(ctx.functionDef(i));
+      typeCheckedFunctionDefs[i] = (FunctionDefinition) visit(ctx.functionDef(i));
     }
 
-    Expression expression = (Expression) this.visit(ctx.expression());
+    for (int i = 0; i < ctx.structDef().size(); i++) {
-    Program result = new Program(funcs, this.structs, expression);
+      typeCheckedStructDefs.put(ctx.structDef(i).structName.getText(), (StructDefinition) visit(ctx.structDef(i)));
-    result.type = expression.type;
+    }
-    result.line = ctx.start.getLine();
+
-    result.col = ctx.start.getCharPositionInLine();
+    var expression = (Expression) visit(ctx.expression());
-    return result;
+    var program = new Program(typeCheckedFunctionDefs, typeCheckedStructDefs, enumDefs, expression);
+    program.type = expression.type;
+    program.line = ctx.start.getLine();
+    program.col = ctx.start.getCharPositionInLine();
+    return program;
   }
 
   @Override
@@ -67,7 +76,7 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
       statements[i] = (Statement) currentStatement;
       actualStatementCount += 1;
 
-      // We use the existance of a type to indicate that this statement returns
+      // We use the existence of a type to indicate that this statement returns
       // something for which the VariableDeclaration is an exception
       if (currentStatement.type != null && !(currentStatement instanceof VariableDeclaration)) {
         // check whether the type matches
@@ -89,9 +98,7 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     // create a shorter statements array and copy the statements to there
     if (actualStatementCount < declaredStatementCount) {
       Statement[] newStatements = new Statement[actualStatementCount];
-      for (int i = 0; i < actualStatementCount; i++) {
+      System.arraycopy(statements, 0, newStatements, 0, actualStatementCount);
-        newStatements[i] = statements[i];
-      }
       statements = newStatements;
     }
 
@@ -172,43 +179,59 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
 
   @Override
   public Node visitVariable_declaration(KlangParser.Variable_declarationContext ctx) {
-    String name = ctx.IDENT().getText();
+    var variableName = ctx.IDENT().getText();
-    int line = ctx.start.getLine();
+    var declaredType = Type.getByName(ctx.type_annotation().type().getText());
-    int col = ctx.start.getCharPositionInLine();
+    var line = ctx.start.getLine();
-    Type declaredType = Type.getByName(ctx.type_annotation().type().getText());
+    var col = ctx.start.getCharPositionInLine();
 
-    if (!declaredType.isPrimitiveType() && this.structs.get(declaredType.getName()) == null) {
+    if (!declaredType.isPrimitiveType() && !structDefs.containsKey(declaredType.getName()) && !enumDefs.containsKey(declaredType.getName())) {
-      String error = "Type " + declaredType.getName() + " not defined.";
+      var error = "Type " + declaredType.getName() + " not defined.";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
-    if (this.vars.get(name) != null) {
+    if (structDefs.containsKey(variableName)) {
-      String error = "Redeclaration of variable with name \"" + name + "\".";
+      var error = "Variable name " + variableName + " shadows a struct of the same name.";
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
+    if (enumDefs.containsKey(variableName)) {
+      var error = "Variable name " + variableName + " shadows an enum of the same name.";
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
+    if (vars.get(variableName) != null) {
+      var error = "Redeclaration of variable with name \"" + variableName + "\".";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
     // Create the appropriate instance
-    VariableDeclaration result;
+    VariableDeclaration variableDeclaration;
     if (ctx.expression() != null) {
-      Node expression = this.visit(ctx.expression());
+      var expression = visit(ctx.expression());
       try {
         declaredType.combine(expression.type);
       } catch (Exception e) {
         throw new RuntimeException(Helper.getErrorPrefix(line, col) + e.getMessage());
       }
-      result = new VariableDeclaration(name, (Expression) expression);
+      variableDeclaration = new VariableDeclaration(variableName, (Expression) expression);
-      result.initialized = true;
+      variableDeclaration.initialized = true;
     } else {
-      result = new VariableDeclaration(name);
+      if (enumDefs.containsKey(declaredType.getName())) {
+        var error = "Variable " + variableName + " references an enum but is not initialized.";
+        throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+      }
+
+      variableDeclaration = new VariableDeclaration(variableName);
     }
 
     // Add it to the global map of variable declarations
-    this.vars.put(name, result);
+    vars.put(variableName, variableDeclaration);
 
-    result.line = line;
+    variableDeclaration.line = line;
-    result.col = col;
+    variableDeclaration.col = col;
-    result.type = declaredType;
+    variableDeclaration.type = declaredType;
-    return result;
+
+    return variableDeclaration;
   }
 
   @Override
@@ -291,7 +314,7 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     String structName = variableDef.type.getName();
     Type fieldType;
     try {
-      fieldType = Helper.drillType(this.structs, structName, path, 0);
+      fieldType = Helper.drillType(this.structDefs, structName, path, 0);
     } catch (Exception e) {
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + e.getMessage());
     }
@@ -311,43 +334,71 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   }
 
   @Override
-  public Node visitStructFieldAccessExpression(KlangParser.StructFieldAccessExpressionContext ctx) {
+  public Node visitMemberAccessExpression(KlangParser.MemberAccessExpressionContext ctx) {
-    String varName = ctx.IDENT(0).getText();
+    var baseName = ctx.IDENT(0).getText();
-    int line = ctx.start.getLine();
+    var line = ctx.start.getLine();
-    int col = ctx.start.getCharPositionInLine();
+    var col = ctx.start.getCharPositionInLine();
-    String[] path = new String[ctx.IDENT().size() - 1];
 
+    // Create a list of member names. This excludes
+    // the first entry as it is the base name.
+    var path = new ArrayList<String>();
     for (int i = 1; i < ctx.IDENT().size(); i++) {
-      path[i - 1] = ctx.IDENT(i).getText();
+      path.add(ctx.IDENT(i).getText());
+    }
+
+    // Determine if the base name points to an enum or a variable
+    var enumDef = enumDefs.get(baseName);
+    if (enumDef != null) {
+      if (path.size() != 1) {
+        var error = "Illegal access to enum " + enumDef.name + ".";
+        throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+      }
+
+      var enumValueName = path.get(0);
+      var enumValue = Arrays.stream(enumDef.enums)
+              .filter(e -> e.value.equals(enumValueName))
+              .findFirst()
+              .orElseThrow(() -> {
+                var error = "Unknown enum value " + enumValueName + " of enum " +  enumDef.name + ".";
+                throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+              });
+
+      var enumAccessExpression = new EnumAccessExpression(baseName, enumValueName, enumValue);
+      enumAccessExpression.type = enumDef.type;
+      enumAccessExpression.line = line;
+      enumAccessExpression.col = col;
+
+      return enumAccessExpression;
     }
 
     // Get the referenced variable, make sure it is defined
-    var variableDef = this.vars.get(varName);
+    var variableDef = vars.get(baseName);
     if (variableDef == null) {
-      String error = "Variable with name " + varName + " not defined.";
+      var error = "Variable with name " + baseName + " not defined.";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
     // Make sure it references a struct
     if (variableDef.type.isPrimitiveType()) {
-      String error = "Variable must reference a struct but references " + variableDef.type.getName() + ".";
+      var error = "Variable must reference a struct but references " + variableDef.type.getName() + ".";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
     // Get the type of the result of this expression
-    String structName = variableDef.type.getName();
+    var structName = variableDef.type.getName();
     Type resultType;
     try {
-      resultType = Helper.drillType(this.structs, structName, path, 0);
+      resultType = Helper.drillType(structDefs, structName, path.toArray(new String[0]), 0);
     } catch (Exception e) {
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + e.getMessage());
     }
 
-    Node result = new StructFieldAccessExpression(varName, structName, path);
+    var memberAccessExpression = new MemberAccessExpression(baseName, structName, path.toArray(new String[0]));
-    result.type = resultType;
+    memberAccessExpression.type = resultType;
-    result.line = line;
+    memberAccessExpression.line = line;
-    result.col = col;
+    memberAccessExpression.col = col;
-    return result;
+
+    return memberAccessExpression;
   }
 
   @Override
@@ -708,7 +759,7 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
 
   @Override
   public Node visitBoolAtom(KlangParser.BoolAtomContext ctx) {
-    Node n = new BooleanExpression(ctx.getText().equals("true") ? true : false);
+    Node n = new BooleanExpression(ctx.getText().equals("true"));
     n.type = Type.getBooleanType();
     n.line = ctx.start.getLine();
     n.col = ctx.start.getCharPositionInLine();
@@ -725,70 +776,137 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   }
 
   @Override
-  public Node visitFunctionDef(KlangParser.FunctionDefContext ctx) {
+  public Node visitStructDef(KlangParser.StructDefContext ctx) {
-    String name = ctx.funcName.getText();
+    var structName = ctx.structName.getText();
-    int line = ctx.start.getLine();
+    var structFieldCount = ctx.structField().size();
-    int col = ctx.start.getCharPositionInLine();
+    var structFields = new StructField[structFieldCount];
-    Type returnType = Type.getByName(ctx.returnType.type().getText());
+    var line = ctx.start.getLine();
-    this.currentDeclaredReturnType = returnType;
+    var col = ctx.start.getCharPositionInLine();
-    this.currentFunctionDefinitionName = name;
 
-    if (!returnType.isPrimitiveType() && this.structs.get(returnType.getName()) == null) {
+    for (int i = 0; i < structFieldCount; i++) {
-      String error = "Type " + returnType.getName() + " not defined.";
+      structFields[i] = (StructField) visit(ctx.structField(i));
+    }
+
+    var structDef = new StructDefinition(structName, structFields);
+    structDef.type = Type.getByName(structName);
+    structDef.line = line;
+    structDef.col = col;
+
+    return structDef;
+  }
+
+  @Override
+  public Node visitStructField(KlangParser.StructFieldContext ctx) {
+    var structFieldName = ctx.IDENT().getText();
+    var structFieldType = Type.getByName(ctx.type_annotation().type().getText());
+    var line = ctx.start.getLine();
+    var col = ctx.start.getCharPositionInLine();
+
+    if (!structFieldType.isPrimitiveType() && !structDefs.containsKey(structFieldType.getName()) && !enumDefs.containsKey(structFieldType.getName())) {
+      var error = "Type " + structFieldType.getName() + " not defined.";
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
+    if (structDefs.containsKey(structFieldName)) {
+      var error = "Struct field name " + structFieldName + " shadows a struct of the same name.";
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
+    if (enumDefs.containsKey(structFieldName)) {
+      var error = "Struct field name " + structFieldName + " shadows an enum of the same name.";
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
+    var structField = new StructField(structFieldName);
+    structField.type = structFieldType;
+    structField.line = line;
+    structField.col = col;
+
+    return structField;
+  }
+
+  @Override
+  public Node visitFunctionDef(KlangParser.FunctionDefContext ctx) {
+    var name = ctx.funcName.getText();
+    var returnType = Type.getByName(ctx.returnType.type().getText());
+    currentDeclaredReturnType = returnType;
+    currentFunctionDefinitionName = name;
+
+    if (!returnType.isPrimitiveType() && !structDefs.containsKey(returnType.getName()) && !enumDefs.containsKey(returnType.getName())) {
+      var line = ctx.returnType.start.getLine();
+      var col = ctx.returnType.start.getCharPositionInLine();
+      var error = "Type " + returnType.getName() + " not defined.";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
     // Create a new set for the variables of the current function
-    // this will be filled in the variable declaration visitor aswell
+    // this will be filled in the variable declaration visitor as well
-    this.vars = new HashMap<>();
+    vars = new HashMap<>();
 
-    // Process the paremter list by visiting every paremter in it
+    // Process the parameter list by visiting every parameter in it
-    int paramCount = ctx.params.parameter().size();
+    var paramCount = ctx.params.parameter().size();
-    Parameter[] params = new Parameter[paramCount];
+    var params = new Parameter[paramCount];
     for (int i = 0; i < paramCount; i++) {
       // Add the parameter to the list of parameters
-      Parameter param = (Parameter) this.visit(ctx.params.parameter(i));
+      var param = (Parameter) visit(ctx.params.parameter(i));
       params[i] = param;
 
       // add the param as a variable
-      VariableDeclaration var = new VariableDeclaration(param.name);
+      var var = new VariableDeclaration(param.name);
       var.initialized = true; // parameters can always be considered initialized
       var.type = param.type;
-      this.vars.put(param.name, var);
+      vars.put(param.name, var);
     }
 
     // Visit the block, make sure that a return value is guaranteed
-    Node block = this.visit(ctx.braced_block());
+    var block = visit(ctx.braced_block());
     if (block.type == null) {
-      String error = "Function " + name + " has to return something of type " + returnType.getName() + ".";
+      var line = ctx.braced_block().start.getLine();
+      var col = ctx.braced_block().start.getCharPositionInLine();
+      var error = "Function " + name + " has to return something of type " + returnType.getName() + ".";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
-    FunctionDefinition result = new FunctionDefinition(name, params, (Block) block);
+    var functionDef = new FunctionDefinition(name, params, (Block) block);
-    result.type = returnType;
+    functionDef.type = returnType;
+    functionDef.line = ctx.start.getLine();
+    functionDef.col = ctx.start.getCharPositionInLine();
 
-    result.line = ctx.start.getLine();
+    return functionDef;
-    result.col = ctx.start.getCharPositionInLine();
-    return result;
   }
 
   @Override
   public Node visitParameter(KlangParser.ParameterContext ctx) {
-    String name = ctx.IDENT().getText();
+    var parameterName = ctx.IDENT().getText();
-    int line = ctx.start.getLine();
+    var parameterType = Type.getByName(ctx.type_annotation().type().getText());
-    int col = ctx.start.getCharPositionInLine();
-    Type type = Type.getByName(ctx.type_annotation().type().getText());
 
-    if (!type.isPrimitiveType() && this.structs.get(type.getName()) == null) {
+    if (structDefs.containsKey(parameterName)) {
-      String error = "Type " + type.getName() + " not defined.";
+      var line = ctx.start.getLine();
+      var col = ctx.start.getCharPositionInLine();
+      var error = "Parameter name " + parameterName + " duplicates a struct of the same name.";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
-    Parameter result = new Parameter(name);
+    if (enumDefs.containsKey(parameterName)) {
-    result.type = type;
+      var line = ctx.start.getLine();
-    result.line = line;
+      var col = ctx.start.getCharPositionInLine();
-    result.col = col;
+      var error = "Parameter name " + parameterName + " duplicates an enum of the same name.";
-    return result;
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
+    if (!parameterType.isPrimitiveType() && !structDefs.containsKey(parameterType.getName()) && !enumDefs.containsKey(parameterType.getName())) {
+      var line = ctx.type_annotation().start.getLine();
+      var col = ctx.type_annotation().start.getCharPositionInLine();
+      var error = "Type " + parameterType.getName() + " not defined.";
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
+    var parameter = new Parameter(parameterName);
+    parameter.type = parameterType;
+    parameter.line = ctx.start.getLine();
+    parameter.col = ctx.start.getCharPositionInLine();
+
+    return parameter;
   }
 
   @Override
@@ -797,15 +915,15 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     int line = ctx.start.getLine();
     int col = ctx.start.getCharPositionInLine();
 
-    FunctionInformation func = this.funcs.get(name);
+    var functionDef = this.functionDefs.get(name);
-    if (func == null) {
+    if (functionDef == null) {
       String error = "Function with name \"" + name + "\" not defined.";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
     // Make sure the number of arguments matches the number of parameters
     int argCount = ctx.functionCall().arguments().expression().size();
-    int paramCount = func.parameters.size();
+    int paramCount = functionDef.parameters.length;
     if (argCount != paramCount) {
       String error = "Function \"" + name + "\" expects " + paramCount + " parameters, but got " + argCount + ".";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
@@ -815,14 +933,14 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     Expression[] args = new Expression[argCount];
     for (int i = 0; i < argCount; i++) {
       Expression expression = (Expression) this.visit(ctx.functionCall().arguments().expression(i));
-      if (!expression.type.equals(func.signature[i])) {
+      if (!expression.type.equals(functionDef.parameters[i].type)) {
-        throw new RuntimeException(Helper.getErrorPrefix(line, col) + "argument " + i + " Expected " + func.signature[i].getName() + " but got: " + expression.type.getName());
+        throw new RuntimeException(Helper.getErrorPrefix(line, col) + "argument " + i + " Expected " + functionDef.parameters[i].type.getName() + " but got: " + expression.type.getName());
       }
       args[i] = expression;
     }
 
     FunctionCall result = new FunctionCall(name, args);
-    result.type = func.returnType;
+    result.type = functionDef.type;
     result.line = line;
     result.col = col;
     return result;
@@ -835,7 +953,7 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     int col = ctx.start.getCharPositionInLine();
     
     // Get the corresponding struct definition
-    var struct = this.structs.get(name);
+    var struct = this.structDefs.get(name);
     if (struct == null) {
       String error = "Struct with name \"" + name + "\" not defined.";
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);

src/main/java/de/hsrm/compiler/Klang/GetDefinitions.java

@@ -0,0 +1,220 @@
+package de.hsrm.compiler.Klang;
+
+import de.hsrm.compiler.Klang.helper.Helper;
+import de.hsrm.compiler.Klang.nodes.*;
+import de.hsrm.compiler.Klang.types.NamedType;
+import de.hsrm.compiler.Klang.types.Type;
+
+import java.util.*;
+
+public class GetDefinitions extends KlangBaseVisitor<Node> {
+    private final Map<String, FunctionDefinition> functionDefs;
+    private final Map<String, StructDefinition> structDefs;
+    private final Map<String, EnumDefinition> enumDefs;
+
+    private Set<String> functionNames;
+    private Set<String> structNames;
+    private Set<String> enumNames;
+
+    public GetDefinitions(
+            Map<String, FunctionDefinition> functionDefs,
+            Map<String, StructDefinition> structDefs,
+            Map<String, EnumDefinition> enumDefs
+    ) {
+        this.functionDefs = functionDefs;
+        this.structDefs = structDefs;
+        this.enumDefs = enumDefs;
+    }
+
+    private Set<String> collectFunctionNames(KlangParser.ProgramContext ctx) {
+        var result = new HashSet<String>();
+        for (int i = 0; i < ctx.functionDef().size(); i++) {
+            var currentFunctionDef = ctx.functionDef(i);
+            var funcName = currentFunctionDef.funcName.getText();
+            if (result.contains(funcName)) {
+                var line = currentFunctionDef.funcName.getLine();
+                var col = currentFunctionDef.funcName.getCharPositionInLine();
+                var error = "Function " + funcName + " defined multiple times.";
+                throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+            }
+            result.add(funcName);
+        }
+        return result;
+    }
+
+    private Set<String> collectStructNames(KlangParser.ProgramContext ctx) {
+        var result = new HashSet<String>();
+        for (int i = 0; i < ctx.structDef().size(); i++) {
+            var currentStructDef = ctx.structDef(i);
+            var structName = currentStructDef.structName.getText();
+            if (result.contains(structName)) {
+                var line = currentStructDef.structName.getLine();
+                var col = currentStructDef.structName.getCharPositionInLine();
+                var error = "Struct " + structName + " defined multiple times.";
+                throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+            }
+            result.add(structName);
+        }
+        return result;
+    }
+
+    private Set<String> collectEnumNames(KlangParser.ProgramContext ctx) {
+        var result = new HashSet<String>();
+        for (int i = 0; i < ctx.enumDef().size(); i++) {
+            var currentEnumDef = ctx.enumDef(i);
+            var enumName = currentEnumDef.enumName.getText();
+            if (result.contains(enumName)) {
+                var line = currentEnumDef.enumName.getLine();
+                var col = currentEnumDef.enumName.getCharPositionInLine();
+                var error = "Enum " + enumName + " defined multiple times.";
+                throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+            }
+            result.add(enumName);
+        }
+        return result;
+    }
+
+    @Override
+    public Node visitProgram(KlangParser.ProgramContext ctx) {
+        functionNames = collectFunctionNames(ctx);
+        structNames = collectStructNames(ctx);
+        enumNames = collectEnumNames(ctx);
+
+        for (int i = 0; i < ctx.functionDef().size(); i++) {
+            visit(ctx.functionDef(i));
+        }
+
+        for (int i = 0; i < ctx.structDef().size(); i++) {
+            visit(ctx.structDef(i));
+        }
+
+        for (int i = 0; i < ctx.enumDef().size(); i++) {
+            visit(ctx.enumDef(i));
+        }
+
+        return null;
+    }
+
+    @Override
+    public Node visitEnumDef(KlangParser.EnumDefContext ctx) {
+        // Check that there isn't a function or struct with the same name
+        var enumName = ctx.enumName.getText();
+        if (functionNames.contains(enumName) || structNames.contains(enumName)) {
+            var line = ctx.start.getLine();
+            var col = ctx.start.getCharPositionInLine();
+            var error = "Duplicate use of name " + enumName + ".";
+            throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+        }
+
+        // IDENT() includes the enumName as the first entry, which we skip
+        var enumValues = new LinkedHashMap<String, EnumValue>();
+        for (int i = 1; i < ctx.IDENT().size(); i++) {
+            var currentEnumField = ctx.IDENT(i);
+            var currentEnumFieldName = currentEnumField.getText();
+            var line = currentEnumField.getSymbol().getLine();
+            var col = currentEnumField.getSymbol().getCharPositionInLine();
+
+            if (enumValues.containsKey(currentEnumFieldName)) {
+                var error = " Duplicate enum value " + currentEnumFieldName + " in enum " + enumName + ".";
+                throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+            }
+
+            var enumValue = new EnumValue(currentEnumFieldName, i - 1);
+            enumValue.line = line;
+            enumValue.col = col;
+
+            enumValues.put(currentEnumFieldName, enumValue);
+        }
+
+        var enumDef = new EnumDefinition(enumName, enumValues.values().toArray(new EnumValue[0]));
+        enumDef.line = ctx.start.getLine();
+        enumDef.col = ctx.start.getCharPositionInLine();
+        enumDef.type = new NamedType(enumName);
+        enumDefs.put(enumName, enumDef);
+
+        return null;
+    }
+
+    @Override
+    public Node visitStructDef(KlangParser.StructDefContext ctx) {
+        var structName = ctx.structName.getText();
+        var structFieldCount = ctx.structField().size();
+        var structFields = new LinkedHashMap<String, StructField>();
+        var line = ctx.start.getLine();
+        var col = ctx.start.getCharPositionInLine();
+
+        // Check that there isn't a function or enum with the same name
+        if (functionNames.contains(structName) || enumNames.contains(structName)) {
+            var error = "Duplicate use of name " + structName + ".";
+            throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+        }
+
+        for (int i = 0; i < structFieldCount; i++) {
+            var currentStructField = ctx.structField(i);
+            var structFieldName = currentStructField.IDENT().getText();
+            var structFieldLine = currentStructField.start.getLine();
+            var structFieldCol = currentStructField.start.getCharPositionInLine();
+
+            if (structFields.containsKey(structFieldName)) {
+                var error = "Duplicate struct field " + structFieldName + " in struct " + structName + ".";
+                throw new RuntimeException(Helper.getErrorPrefix(structFieldLine, structFieldCol) + error);
+            }
+
+            var structField = new StructField(structFieldName);
+            structField.type = Type.getByName(currentStructField.type_annotation().type().getText());
+            structField.line = structFieldLine;
+            structField.col = structFieldCol;
+
+            structFields.put(structFieldName, structField);
+        }
+
+        var structDef = new StructDefinition(structName, structFields.values().toArray(new StructField[0]));
+        structDef.line = line;
+        structDef.col = col;
+        structDef.type = new NamedType(structName);
+        structDefs.put(structName, structDef);
+
+        return null;
+    }
+
+    @Override
+    public Node visitFunctionDef(KlangParser.FunctionDefContext ctx) {
+        var funcName = ctx.funcName.getText();
+        var paramCount = ctx.params.parameter().size();
+        var parameters = new LinkedHashMap<String, Parameter>();
+        var line = ctx.start.getLine();
+        var col = ctx.start.getCharPositionInLine();
+
+        // Check that there isn't a struct or enum with the same name
+        if (structNames.contains(funcName) || enumNames.contains(funcName)) {
+            var error = "Duplicate use of name " + funcName + ".";
+            throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+        }
+
+        for (int i = 0; i < paramCount; i++) {
+            var currentParam = ctx.params.parameter(i);
+            var paramName = currentParam.IDENT().getText();
+            var paramLine = currentParam.start.getLine();
+            var paramCol = currentParam.start.getCharPositionInLine();
+
+            if (parameters.containsKey(paramName)) {
+                var error = "Duplicate parameter name " + paramName + " in function " + funcName + ".";
+                throw new RuntimeException(Helper.getErrorPrefix(paramLine, paramCol) + error);
+            }
+
+            var parameter = new Parameter(paramName);
+            parameter.type = Type.getByName(currentParam.type_annotation().type().getText());
+            parameter.line = paramLine;
+            parameter.col = paramCol;
+
+            parameters.put(paramName, parameter);
+        }
+
+        var functionDef = new FunctionDefinition(funcName, parameters.values().toArray(new Parameter[0]), null);
+        functionDef.type = Type.getByName(ctx.returnType.type().getText());
+        functionDef.line = line;
+        functionDef.col = col;
+        functionDefs.put(funcName, functionDef);
+        return null;
+    }
+}

src/main/java/de/hsrm/compiler/Klang/GetFunctions.java

@@ -1,54 +0,0 @@
-package de.hsrm.compiler.Klang;
-
-import java.util.Map;
-import java.util.TreeMap;
-
-import de.hsrm.compiler.Klang.types.*;
-import de.hsrm.compiler.Klang.helper.*;
-
-public class GetFunctions extends KlangBaseVisitor<Void> {
-
-  private Map<String, FunctionInformation> funcs;
-
-  public GetFunctions(Map<String, FunctionInformation> funcs) {
-    this.funcs = funcs;
-  }
-
-  @Override
-  public Void visitProgram(KlangParser.ProgramContext ctx) {
-    for (int i = 0; i < ctx.functionDef().size(); i++) {
-      this.visit(ctx.functionDef(i));
-    }
-    return null;
-  }
-
-  @Override
-  public Void visitFunctionDef(KlangParser.FunctionDefContext ctx) {
-    String name = ctx.funcName.getText();
-    int line = ctx.start.getLine();
-    int col = ctx.start.getCharPositionInLine();
-
-    if (this.funcs.containsKey(name)) {
-      String error = "Function " + name + " defined multiple times.";
-      throw new Error(Helper.getErrorPrefix(line, col) + error);
-    }
-    
-    Type returnType = Type.getByName(ctx.returnType.type().getText());
-
-    TreeMap<String, Type> parameters = new TreeMap<String, Type>();
-
-    // Process the paremter list by visiting every paremter in it
-    int paramCount = ctx.params.parameter().size();
-    Type[] signature = new Type[paramCount];
-    for (int i = 0; i < paramCount; i++) {
-      Type paramType = Type.getByName(ctx.params.parameter(i).type_annotation().type().getText());
-      String paramName = ctx.params.parameter(i).IDENT().getText();
-      parameters.put(paramName, paramType);
-      signature[i] = paramType;
-    }
-
-    FunctionInformation information = new FunctionInformation(name, returnType, parameters, signature);
-    this.funcs.put(name, information);
-    return null;
-  }
-}

src/main/java/de/hsrm/compiler/Klang/GetStructNames.java

@@ -1,37 +0,0 @@
-package de.hsrm.compiler.Klang;
-
-import java.util.Set;
-
-import de.hsrm.compiler.Klang.helper.Helper;
-
-public class GetStructNames extends KlangBaseVisitor<Void> {
-    private Set<String> structNames;
-
-    public GetStructNames(Set<String> structNames) {
-        this.structNames = structNames;
-    }
-
-    @Override
-    public Void visitProgram(KlangParser.ProgramContext ctx) {
-        for (int i = 0; i < ctx.structDef().size(); i++) {
-            this.visit(ctx.structDef(i));
-        }
-
-        return null;
-    }
-
-    @Override
-    public Void visitStructDef(KlangParser.StructDefContext ctx) {
-        String name = ctx.structName.getText();
-        int line = ctx.start.getLine();
-        int col = ctx.start.getCharPositionInLine();
-
-        if (this.structNames.contains(name)) {
-            String error = "Struct " + name + " defined multiple times.";
-            throw new Error(Helper.getErrorPrefix(line, col) + error);
-        }
-
-        this.structNames.add(name);
-        return null;
-    }
-}

src/main/java/de/hsrm/compiler/Klang/GetStructs.java

@@ -1,70 +0,0 @@
-package de.hsrm.compiler.Klang;
-
-import java.util.Map;
-import java.util.Set;
-
-import de.hsrm.compiler.Klang.helper.Helper;
-import de.hsrm.compiler.Klang.nodes.Node;
-import de.hsrm.compiler.Klang.nodes.StructDefinition;
-import de.hsrm.compiler.Klang.nodes.StructField;
-import de.hsrm.compiler.Klang.types.StructType;
-import de.hsrm.compiler.Klang.types.Type;
-
-public class GetStructs extends KlangBaseVisitor<Node> {
-
-    private Set<String> structNames;
-    private Map<String, StructDefinition> structs;
-
-    public GetStructs(Set<String> structNames, Map<String, StructDefinition> structs) {
-        this.structs = structs;
-        this.structNames = structNames;
-    }
-
-    @Override
-    public Node visitProgram(KlangParser.ProgramContext ctx) {
-        for (int i = 0; i < ctx.structDef().size(); i++) {
-            this.visit(ctx.structDef(i));
-        }
-
-        return null;
-    }
-
-    @Override
-    public Node visitStructDef(KlangParser.StructDefContext ctx) {
-        String name = ctx.structName.getText();
-        int line = ctx.start.getLine();
-        int col = ctx.start.getCharPositionInLine();
-        StructField[] fields = new StructField[ctx.structField().size()];
-    
-        for (int i = 0; i < ctx.structField().size(); i++) {
-          StructField field = (StructField) this.visit(ctx.structField(i));
-          fields[i] = field;
-        }
-    
-        StructDefinition result = new StructDefinition(name, fields);
-        result.line = line;
-        result.col = col;
-        result.type = new StructType(name);
-        this.structs.put(name, result);
-        return null;
-    }
-
-    @Override
-    public Node visitStructField(KlangParser.StructFieldContext ctx) {
-      String name = ctx.IDENT().getText();
-      int line = ctx.start.getLine();
-      int col = ctx.start.getCharPositionInLine();
-      Type type = Type.getByName(ctx.type_annotation().type().getText());
-  
-      if (!type.isPrimitiveType() && !this.structNames.contains(type.getName())) {
-        String error = "Type " + type.getName() + " not defined.";
-        throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
-      }
-  
-      Node result = new StructField(name);
-      result.type = type;
-      result.line = line;
-      result.col = col;
-      return result;
-    }
-}

src/main/java/de/hsrm/compiler/Klang/Klang.java

@@ -1,19 +1,22 @@
 package de.hsrm.compiler.Klang;
 
-// import ANTLR's runtime libraries
+import de.hsrm.compiler.Klang.nodes.EnumDefinition;
-import org.antlr.v4.runtime.*;
+import de.hsrm.compiler.Klang.nodes.FunctionDefinition;
-import org.antlr.v4.runtime.tree.*;
-
-import java.io.*;
-import java.util.Arrays;
-import java.util.List;
-import java.util.HashMap;
-import java.util.HashSet;
-
 import de.hsrm.compiler.Klang.nodes.Node;
 import de.hsrm.compiler.Klang.nodes.StructDefinition;
-import de.hsrm.compiler.Klang.visitors.*;
+import de.hsrm.compiler.Klang.visitors.EvalVisitor;
-import de.hsrm.compiler.Klang.helper.*;
+import de.hsrm.compiler.Klang.visitors.GenASM;
+import de.hsrm.compiler.Klang.visitors.PrettyPrintVisitor;
+import org.antlr.v4.runtime.CharStream;
+import org.antlr.v4.runtime.CharStreams;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.tree.ParseTree;
+
+import java.io.FileWriter;
+import java.io.StringWriter;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
 
 public class Klang {
 
@@ -87,22 +90,15 @@ public class Klang {
 
     // Context Analysis and DAST generation
     Node root;
-    HashMap<String, StructDefinition> structs;
+    var functionDefs = new HashMap<String, FunctionDefinition>();
+    var structDefs = new HashMap<String, StructDefinition>();
+    var enumDefs = new HashMap<String, EnumDefinition>();
     try {
-      // Extract information about all functions
+      // Extract information about all definitions
-      var functionDefinitions = new HashMap<String, FunctionInformation>();
+      new GetDefinitions(functionDefs, structDefs, enumDefs).visit(tree);
-      new GetFunctions(functionDefinitions).visit(tree);
-
-      // Extract names of all structs
-      var structNames = new HashSet<String>();
-      new GetStructNames(structNames).visit(tree);
-
-      // Extract information about all structs
-      structs = new HashMap<String, StructDefinition>();
-      new GetStructs(structNames, structs).visit(tree);
 
       // Create the DAST
-      ContextAnalysis ctxAnal = new ContextAnalysis(functionDefinitions, structs);
+      ContextAnalysis ctxAnal = new ContextAnalysis(functionDefs, structDefs, enumDefs);
       root = ctxAnal.visit(tree);
     } catch (Exception e) {
       System.err.println(e.getMessage());
@@ -122,18 +118,15 @@ public class Klang {
     if (evaluate) {
       // Evaluate the sourcecode and print the result
       System.out.println("\nEvaluating the source code:");
-      EvalVisitor evalVisitor = new EvalVisitor(structs);
+      EvalVisitor evalVisitor = new EvalVisitor(structDefs);
       Value result = root.welcome(evalVisitor);
       generateOutput(out, "Result was: " + result.asObject().toString());
       return;
     }
 
     // Generate assembler code
-    // System.out.println("\nPrinting the assembler code");
+    GenASM genasm = new GenASM(mainName, structDefs);
-    StringWriter wAsm = new StringWriter();
-    GenASM.ExWriter exAsm = new GenASM.ExWriter(wAsm);
-    GenASM genasm = new GenASM(exAsm, mainName, structs);
     root.welcome(genasm);
-    generateOutput(out, wAsm.toString());
+    generateOutput(out, genasm.toAsm());
   }
 }

src/main/java/de/hsrm/compiler/Klang/asm/ASM.java

@@ -0,0 +1,218 @@
+package de.hsrm.compiler.Klang.asm;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import de.hsrm.compiler.Klang.asm.mnemonics.*;
+
+public class ASM {
+  private List<Mnemonic> mnemonics;
+
+  public ASM() {
+    this.mnemonics = new ArrayList<Mnemonic>();
+  }
+
+  public void push(String dataType, int immediate) {
+    mnemonics.add(new Push(dataType, immediate));
+  }
+
+  public void push(String dataType, String operand) {
+    mnemonics.add(new Push(dataType, operand));
+  }
+
+  public void pop(String dataType, String operand) {
+    mnemonics.add(new Pop(dataType, operand));
+  }
+
+  public void mov(String dataType, String src, String dst) {
+    mnemonics.add(new Mov(dataType, src, dst));
+  }
+
+  public void mov(String dataType, String label, String src, String dst) {
+    mnemonics.add(new Mov(dataType, label, src, dst));
+  }
+
+  public void mov(String dataType, int offset, String src, String dst) {
+    mnemonics.add(new Mov(dataType, offset, src, dst));
+  }
+
+  public void mov(String dataType, String src, int offset, String dst) {
+    mnemonics.add(new Mov(dataType, src, offset, dst));
+  }
+
+  public void mov(String dataType, int immediate, String dst) {
+    mnemonics.add(new Mov(dataType, immediate, dst));
+  }
+
+  public void ucomi(String dataType, String src, String dst) {
+    mnemonics.add(new Ucomi(dataType, src, dst));
+  }
+
+  public void cmp(String dataType, String src, String dst) {
+    mnemonics.add(new Cmp(dataType, src, dst));
+  }
+
+  public void cmp(String dataType, int immediate, String dst) {
+    mnemonics.add(new Cmp(dataType, immediate, dst));
+  }
+
+  public void je(int label) {
+    mnemonics.add(new Je(label));
+  }
+
+  public void je(String labelPrefix, int label) {
+    mnemonics.add(new Je(labelPrefix, label));
+  }
+
+  public void jmp(int label) {
+    mnemonics.add(new Jmp(label));
+  }
+
+  public void jmp(String labelPrefix, int label) {
+    mnemonics.add(new Jmp(labelPrefix, label));
+  }
+
+  public void jne(int label) {
+    mnemonics.add(new Jne(label));
+  }
+
+  public void jne(String labelPrefix, int label) {
+    mnemonics.add(new Jne(labelPrefix, label));
+  }
+
+  public void jg(int label) {
+    mnemonics.add(new Jg(label));
+  }
+
+  public void jg(String labelPrefix, int label) {
+    mnemonics.add(new Jg(labelPrefix, label));
+  }
+
+  public void jge(int label) {
+    mnemonics.add(new Jge(label));
+  }
+
+  public void jge(String labelPrefix, int label) {
+    mnemonics.add(new Jge(labelPrefix, label));
+  }
+
+  public void jl(int label) {
+    mnemonics.add(new Jl(label));
+  }
+
+  public void jl(String labelPrefix, int label) {
+    mnemonics.add(new Jl(labelPrefix, label));
+  }
+
+  public void jle(int label) {
+    mnemonics.add(new Jle(label));
+  }
+
+  public void jle(String labelPrefix, int label) {
+    mnemonics.add(new Jle(labelPrefix, label));
+  }
+
+  public void jz(int label) {
+    mnemonics.add(new Jz(label));
+  }
+
+  public void jz(String labelPrefix, int label) {
+    mnemonics.add(new Jz(labelPrefix, label));
+  }
+
+  public void jnz(int label) {
+    mnemonics.add(new Jnz(label));
+  }
+
+  public void jnz(String labelPrefix, int label) {
+    mnemonics.add(new Jnz(labelPrefix, label));
+  }
+
+  public void label(int label) {
+    mnemonics.add(new Label(label));
+  }
+
+  public void label(String labelPrefix, int label) {
+    mnemonics.add(new Label(labelPrefix, label));
+  }
+
+  public void add(String dataType, String src, String dst) {
+    mnemonics.add(new Add(dataType, src, dst));
+  }
+
+  public void add(String dataType, String src, int dstOffset, String dst) {
+    mnemonics.add(new Add(dataType, src, dstOffset, dst));
+  }
+
+  public void add(String dataType, int immediate, String dst) {
+    mnemonics.add(new Add(dataType, immediate, dst));
+  }
+  
+  public void sub(String dataType, String src, String dst) {
+    mnemonics.add(new Sub(dataType, src, dst));
+  }
+  
+  public void mul(String dataType, String src, String dst) {
+    mnemonics.add(new Mul(dataType, src, dst));
+  }
+  
+  public void div(String dataType, String src, String dst) {
+    mnemonics.add(new Div(dataType, src, dst));
+  }
+
+  public void idiv(String dataType, String operand) {
+    mnemonics.add(new Idiv(dataType, operand));
+  }
+  
+  public void imul(String dataType, String src, String dst) {
+    mnemonics.add(new Imul(dataType, src, dst));
+  }
+
+  public void cqto() {
+    mnemonics.add(new Cqto());
+  }
+
+  public void ret() {
+    mnemonics.add(new Ret());
+  }
+
+  public void xor(String dataType, String src, String dst) {
+    mnemonics.add(new Xor(dataType, src, dst));
+  }
+
+  public void neg(String operand) {
+    mnemonics.add(new Neg(operand));
+  }
+
+  public void functionHead(String functionName) {
+    mnemonics.add(new FunctionHead(functionName));
+  }
+
+  public void call(String operand) {
+    mnemonics.add(new Call(operand));
+  }
+  
+  public void text(String text) {
+    mnemonics.add(new Text(text));
+  }
+
+  public void newline() {
+    mnemonics.add(new Newline());
+  }
+
+  public void cvtsi2sd(String src, String dst) {
+    mnemonics.add(new Cvtsi2sd(src, dst));
+  }
+
+  public String toAsm() {
+    StringBuilder sb = new StringBuilder();
+    mnemonics.stream().forEach(x -> {
+      for (int i = 0; i < x.indentation; i++) {
+        sb.append("\t");
+      }
+      sb.append(x.toAsm());
+      sb.append("\n");
+    });
+    return sb.toString();
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Add.java

@@ -0,0 +1,29 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Add extends TwoOperandMnemonic {
+  public String dataType;
+  
+  public Add(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  public Add(String dataType, String src, int dstOffset, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dstOffset + "(" + dst + ")";
+  }
+
+  public Add(String dataType, int immediate, String dst) {
+    this.dataType = dataType;
+    this.src = "$" + immediate;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "add" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Call.java

@@ -0,0 +1,14 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Call extends OneOperandMnemonic {
+
+  public Call(String operand) {
+    this.operand = operand;
+  }
+
+  @Override
+  public String toAsm() {
+    return "call " + this.operand; 
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Cmp.java

@@ -0,0 +1,22 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Cmp extends TwoOperandMnemonic {
+  public String dataType;
+  
+  public Cmp(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  public Cmp(String dataType, int immediate, String dst) {
+    this.dataType = dataType;
+    this.src = "$" + immediate;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "cmp" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Cqto.java

@@ -0,0 +1,8 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Cqto extends NoOperandMnemonic {
+  @Override
+  public String toAsm() {
+    return "cqto";
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Cvtsi2sd.java

@@ -0,0 +1,15 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Cvtsi2sd extends TwoOperandMnemonic {
+
+  public Cvtsi2sd(String src, String dst) {
+    this.src = src;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "cvtsi2sd " + this.src + ", " + this.dst;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Div.java

@@ -0,0 +1,17 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Div extends TwoOperandMnemonic {
+  public String dataType;
+
+  public Div(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "div" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/FunctionHead.java

@@ -0,0 +1,26 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class FunctionHead extends NoOperandMnemonic {
+
+  public String functionName;
+
+  public FunctionHead(String functionName) {
+    this.functionName = functionName;
+    this.indentation = 0;
+  }
+
+  @Override
+  public String toAsm() {
+    StringBuilder sb = new StringBuilder();
+    sb.append(".globl ");
+    sb.append(this.functionName);
+    sb.append("\n");
+    sb.append(".type ");
+    sb.append(this.functionName);
+    sb.append(", @function\n");
+    sb.append(this.functionName);
+    sb.append(":");
+    return sb.toString();
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Idiv.java

@@ -0,0 +1,16 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Idiv extends OneOperandMnemonic{
+  public String dataType;
+
+  public Idiv(String dataType, String operand) {
+    this.dataType = dataType;
+    this.operand = operand;
+  }
+
+  @Override
+  public String toAsm() {
+    return "idiv" + this.dataType + " " + this.operand;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Imul.java

@@ -0,0 +1,17 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Imul extends TwoOperandMnemonic {
+  public String dataType;
+
+  public Imul(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "imul" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Je.java

@@ -0,0 +1,12 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Je extends Jump {
+  
+  public Je(int label) {
+    super("je", label);
+  }
+
+  public Je(String labelPrefix, int label) {
+    super("je", labelPrefix, label);
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jg.java

@@ -0,0 +1,11 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Jg extends Jump {
+  public Jg(int label) {
+    super("jg", label);
+  }
+
+  public Jg(String labelPrefix, int label) {
+    super("jg", labelPrefix, label);
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jge.java

@@ -0,0 +1,11 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Jge extends Jump {
+  public Jge(int label) {
+    super("jge", label);
+  }
+
+  public Jge(String labelPrefix, int label) {
+    super("jge", labelPrefix, label);
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jl.java

@@ -0,0 +1,11 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Jl extends Jump {
+  public Jl(int label) {
+    super("jl", label);
+  }
+
+  public Jl(String labelPrefix, int label) {
+    super("jl", labelPrefix, label);
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jle.java

@@ -0,0 +1,11 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Jle extends Jump {
+  public Jle(int label) {
+    super("jle", label);
+  }
+
+  public Jle(String labelPrefix, int label) {
+    super("jle", labelPrefix, label);
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jmp.java

@@ -0,0 +1,11 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Jmp extends Jump {
+  public Jmp(String labelPrefix, int label) {
+    super("jmp", labelPrefix, label);
+  }
+
+  public Jmp(int label) {
+    super("jmp", label);
+  }  
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jne.java

@@ -0,0 +1,11 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Jne extends Jump {
+  public Jne(int label) {
+    super("jne", label);
+  }
+
+  public Jne(String labelPrefix, int label) {
+    super("jne", labelPrefix, label);
+  } 
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jnz.java

@@ -0,0 +1,11 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Jnz extends Jump {
+  public Jnz(int label) {
+    super("jnz", label);
+  }
+
+  public Jnz(String labelPrefix, int label) {
+    super("jnz", labelPrefix, label);
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jump.java

@@ -0,0 +1,21 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public abstract class Jump extends Mnemonic {
+  protected String opcode;
+  public String labelPrefix = "L";
+  public int label;
+  public Jump(String opcode, String labelPrefix, int label) {
+    this.opcode = opcode;
+    this.labelPrefix = labelPrefix;
+    this.label = label;
+  }
+
+  public Jump(String opcode, int label) {
+    this.opcode = opcode;
+    this.label = label;
+  }
+  @Override
+  public String toAsm() {
+    return this.opcode + " ." + this.labelPrefix + this.label;
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Jz.java

@@ -0,0 +1,11 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Jz extends Jump {
+  public Jz(int label) {
+    super("jz", label);
+  }
+
+  public Jz(String labelPrefix, int label) {
+    super("jz", labelPrefix, label);
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Label.java

@@ -0,0 +1,22 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Label extends Mnemonic {
+  public String labelPrefix = "L";
+  public int label;
+
+  public Label(int label) {
+    this.label = label;
+    this.indentation = 0;
+  }
+  
+  public Label(String labelPrefix, int label) {
+    this.labelPrefix = labelPrefix;
+    this.label = label;
+    this.indentation = 0;
+  }
+
+  @Override
+  public String toAsm() {
+    return "." + this.labelPrefix + this.label + ":";
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Mnemonic.java

@@ -0,0 +1,6 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public abstract class Mnemonic {
+  public abstract String toAsm();
+  public int indentation = 2;
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Mov.java

@@ -0,0 +1,40 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Mov extends TwoOperandMnemonic{
+  public String dataType = "q";
+
+  public Mov(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  public Mov(String dataType, String label, String src, String dst) {
+    this.dataType = dataType;
+    this.src = label + "(" + src + ")";
+    this.dst = dst;
+  }
+
+  public Mov(String dataType, int offset, String src, String dst) {
+    this.dataType = dataType;
+    this.src = offset + "(" + src + ")";
+    this.dst = dst;
+  }
+
+  public Mov(String dataType, int immediate, String dst) {
+    this.dataType = dataType;
+    this.src = "$" + immediate;
+    this.dst = dst;
+  }
+
+  public Mov(String dataType, String src, int offset, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = offset + "(" + dst + ")";
+  }
+
+  @Override
+  public String toAsm() {
+    return "mov" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Mul.java

@@ -0,0 +1,17 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Mul extends TwoOperandMnemonic {
+  public String dataType;
+
+  public Mul(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "mul" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Neg.java

@@ -0,0 +1,14 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Neg extends OneOperandMnemonic {
+
+  public Neg(String operand) {
+    this.operand = operand;
+  }
+
+  @Override
+  public String toAsm() {
+    return "neg " + this.operand;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Newline.java

@@ -0,0 +1,9 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Newline extends NoOperandMnemonic {
+
+  @Override
+  public String toAsm() {
+    return "";
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/NoOperandMnemonic.java

@@ -0,0 +1,5 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public abstract class NoOperandMnemonic extends Mnemonic {
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/OneOperandMnemonic.java

@@ -0,0 +1,5 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public abstract class OneOperandMnemonic extends Mnemonic {
+  public String operand;
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Pop.java

@@ -0,0 +1,16 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Pop extends OneOperandMnemonic {
+  public String dataType;
+
+  public Pop(String dataType, String operand) {
+    this.dataType = dataType;
+    this.operand = operand;
+  }
+
+  @Override
+  public String toAsm() {
+    return "pop" + this.dataType + " " + this.operand;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Push.java

@@ -0,0 +1,21 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Push extends OneOperandMnemonic {
+  public String dataType;
+
+  public Push(String dataType, int immediate){
+    this.dataType = dataType;
+    this.operand = "$" + immediate;
+  }
+
+  public Push(String dataType, String operand) {
+    this.dataType = dataType;
+    this.operand = operand;
+  }
+
+  @Override
+  public String toAsm() {
+    return "push" + this.dataType + " " + this.operand;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Ret.java

@@ -0,0 +1,8 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Ret extends NoOperandMnemonic {
+  @Override
+  public String toAsm() {
+    return "ret";
+  }
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Sub.java

@@ -0,0 +1,17 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Sub extends TwoOperandMnemonic {
+  public String dataType;
+
+  public Sub(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "sub" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Text.java

@@ -0,0 +1,15 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Text extends NoOperandMnemonic {
+  public String text;
+
+  public Text(String text) {
+    this.text = text;
+    this.indentation = 0;
+  }
+
+  @Override
+  public String toAsm() {
+    return this.text;
+  }  
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/TwoOperandMnemonic.java

@@ -0,0 +1,6 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public abstract class TwoOperandMnemonic extends Mnemonic {
+  public String src;
+  public String dst;
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Ucomi.java

@@ -0,0 +1,17 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Ucomi extends TwoOperandMnemonic {
+  public String dataType;
+
+  public Ucomi(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "ucomi" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Xor.java

@@ -0,0 +1,17 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Xor extends TwoOperandMnemonic {
+  public String dataType;
+
+  public Xor(String dataType, String src, String dst) {
+    this.dataType = dataType;
+    this.src = src;
+    this.dst = dst;
+  }
+
+  @Override
+  public String toAsm() {
+    return "xor" + this.dataType + " " + this.src + ", " + this.dst;
+  }
+
+}

src/main/java/de/hsrm/compiler/Klang/helper/FunctionInformation.java

@@ -1,19 +0,0 @@
-package de.hsrm.compiler.Klang.helper;
-
-import java.util.Map;
-
-import de.hsrm.compiler.Klang.types.Type;
-
-public class FunctionInformation {
-  public String name;
-  public Type returnType;
-  public Map<String, Type> parameters;
-  public Type[] signature;
-
-  public FunctionInformation(String name, Type returnType, Map<String,Type> parameters, Type[] signature) {
-    this.name = name;
-    this.returnType = returnType;
-    this.parameters = parameters;
-    this.signature = signature;
-  }  
-}

src/main/java/de/hsrm/compiler/Klang/nodes/EnumDefinition.java

@@ -0,0 +1,19 @@
+package de.hsrm.compiler.Klang.nodes;
+
+import de.hsrm.compiler.Klang.visitors.Visitor;
+
+public class EnumDefinition extends Node {
+
+    public String name;
+    public EnumValue[] enums;
+
+    public EnumDefinition(String name, EnumValue[] enums) {
+        this.name = name;
+        this.enums = enums;
+    }
+
+    @Override
+    public <R> R welcome(Visitor<R> v) {
+        return v.visit(this);
+    }
+}

src/main/java/de/hsrm/compiler/Klang/nodes/EnumValue.java

@@ -0,0 +1,18 @@
+package de.hsrm.compiler.Klang.nodes;
+
+import de.hsrm.compiler.Klang.visitors.Visitor;
+
+public class EnumValue  extends Node {
+    public String value;
+    public int index;
+
+    public EnumValue(String value, int index) {
+        this.value = value;
+        this.index = index;
+    }
+
+    @Override
+    public <R> R welcome(Visitor<R> v) {
+        return v.visit(this);
+    }
+}

src/main/java/de/hsrm/compiler/Klang/nodes/Program.java

@@ -9,11 +9,18 @@ public class Program extends Node {
   
   public FunctionDefinition[] funcs;
   public Map<String, StructDefinition> structs;
+  public Map<String, EnumDefinition> enums;
   public Expression expression;
 
-  public Program(FunctionDefinition[] funcs, Map<String, StructDefinition> structs, Expression expression) {
+  public Program(
+          FunctionDefinition[] funcs,
+          Map<String, StructDefinition> structs,
+          Map<String, EnumDefinition> enums,
+          Expression expression
+  ) {
     this.funcs = funcs;
     this.structs = structs;
+    this.enums = enums;
     this.expression = expression;
   }
 

src/main/java/de/hsrm/compiler/Klang/nodes/expressions/EnumAccessExpression.java

@@ -0,0 +1,26 @@
+package de.hsrm.compiler.Klang.nodes.expressions;
+
+import de.hsrm.compiler.Klang.nodes.EnumDefinition;
+import de.hsrm.compiler.Klang.nodes.EnumValue;
+import de.hsrm.compiler.Klang.visitors.Visitor;
+
+public class EnumAccessExpression extends Expression {
+    public String enumName;
+    public String enumValueName;
+    public EnumValue enumValue;
+
+    public EnumAccessExpression(
+            String enumName,
+            String enumValueName,
+            EnumValue enumValue
+    ) {
+        this.enumName = enumName;
+        this.enumValueName = enumValueName;
+        this.enumValue = enumValue;
+    }
+
+    @Override
+    public <R> R welcome(Visitor<R> v) {
+        return v.visit(this);
+    }
+}

src/main/java/de/hsrm/compiler/Klang/nodes/expressions/MemberAccessExpression.java

@@ -2,12 +2,12 @@ package de.hsrm.compiler.Klang.nodes.expressions;
 
 import de.hsrm.compiler.Klang.visitors.Visitor;
 
-public class StructFieldAccessExpression extends Expression {
+public class MemberAccessExpression extends Expression {
   public String varName;
   public String structName;
   public String[] path;
 
-  public StructFieldAccessExpression(String varName, String structName, String[] path) {
+  public MemberAccessExpression(String varName, String structName, String[] path) {
     this.varName = varName;
     this.structName = structName;
     this.path = path;

src/main/java/de/hsrm/compiler/Klang/types/BooleanType.java

@@ -1,5 +1,7 @@
 package de.hsrm.compiler.Klang.types;
 
+import de.hsrm.compiler.Klang.Value;
+
 public class BooleanType extends PrimitiveType {
 
   private static BooleanType instance = null;
@@ -33,4 +35,8 @@ public class BooleanType extends PrimitiveType {
     throw new RuntimeException("Type missmatch: cannot combine " + this.getName() + " and " + that.getName());
   }
 
+  @Override
+  public boolean valuesEqual(Value a, Value b) {
+    return a.asBoolean() == b.asBoolean();
+  }
 }

src/main/java/de/hsrm/compiler/Klang/types/FloatType.java

@@ -1,5 +1,7 @@
 package de.hsrm.compiler.Klang.types;
 
+import de.hsrm.compiler.Klang.Value;
+
 public class FloatType extends NumericType {
 
   private static FloatType instance = null;
@@ -37,4 +39,8 @@ public class FloatType extends NumericType {
     throw new RuntimeException("Type missmatch: cannot combine " + this.getName() + " and " + that.getName());
   }
 
+  @Override
+  public boolean valuesEqual(Value a, Value b) {
+    return a.asFloat() == b.asFloat();
+  }
 }

src/main/java/de/hsrm/compiler/Klang/types/IntegerType.java

@@ -1,5 +1,7 @@
 package de.hsrm.compiler.Klang.types;
 
+import de.hsrm.compiler.Klang.Value;
+
 public class IntegerType extends NumericType {
 
   private static IntegerType instance = null;
@@ -37,4 +39,9 @@ public class IntegerType extends NumericType {
     throw new RuntimeException("Type missmatch: cannot combine " + this.getName() + " and " + that.getName());
   }
 
+  @Override
+  public boolean valuesEqual(Value a, Value b) {
+    return a.asInteger() == b.asInteger();
+  }
+
 }

src/main/java/de/hsrm/compiler/Klang/types/NamedType.java

@@ -0,0 +1,59 @@
+package de.hsrm.compiler.Klang.types;
+
+import de.hsrm.compiler.Klang.Value;
+import de.hsrm.compiler.Klang.nodes.EnumDefinition;
+import de.hsrm.compiler.Klang.nodes.FunctionDefinition;
+import de.hsrm.compiler.Klang.nodes.StructDefinition;
+
+import java.util.Map;
+
+public class NamedType extends Type {
+    public String name;
+
+    public NamedType(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public Type combine(Type that) {
+        if(this.equals(that)) {
+            return this;
+        }
+
+        throw new RuntimeException("Type mismatch: cannot combine " + getName() + " and " + that.getName());
+    }
+
+    @Override
+    public boolean valuesEqual(Value a, Value b) {
+        return a.asObject().equals(b.asObject());
+    }
+
+    @Override
+    public boolean isPrimitiveType() {
+        return false;
+    }
+
+    @Override
+    public boolean isNumericType() {
+        return false;
+    }
+
+    @Override
+    public boolean equals(Object that) {
+        if (this == that) {
+            return true;
+        }
+
+        if (that instanceof NamedType) {
+            var thatType = (NamedType) that;
+            return getName().equals(thatType.getName());
+        }
+
+        return false;
+    }
+}

src/main/java/de/hsrm/compiler/Klang/types/NullType.java

@@ -1,5 +1,7 @@
 package de.hsrm.compiler.Klang.types;
 
+import de.hsrm.compiler.Klang.Value;
+
 public class NullType extends Type {
 
     private static NullType instance = null;
@@ -28,6 +30,11 @@ public class NullType extends Type {
         return that;
     }
 
+    @Override
+    public boolean valuesEqual(Value a, Value b) {
+        return a.asObject() == b.asObject();
+    }
+
     @Override
     public boolean isPrimitiveType() {
         return false;

src/main/java/de/hsrm/compiler/Klang/types/StructType.java

@@ -1,54 +0,0 @@
-package de.hsrm.compiler.Klang.types;
-
-public class StructType extends Type {
-
-    public String name;
-
-    public StructType(String name) {
-        this.name = name;
-    }
-
-    @Override
-    public String getName() {
-        return this.name;
-    }
-
-    @Override
-    public Type combine(Type that) {
-        if (that.equals(this)) {
-            return this;
-        }
-
-        // If you combine a null type with a struct type, you
-        // always get the struct type back. 
-        if (that == NullType.getType()) {
-            return this;
-        }
-
-        throw new RuntimeException("Type missmatch: cannot combine " + this.getName() + " and " + that.getName());
-    }
-
-    @Override
-    public boolean isPrimitiveType() {
-        return false;
-    }
-
-    @Override
-    public boolean equals(Object that) {
-        if (this == that) {
-            return true;
-        }
-
-        if (that instanceof StructType) {
-            StructType thatType = (StructType) that;
-            return this.getName().equals(thatType.getName());
-        }
-
-        return false;
-    }
-
-    @Override
-    public boolean isNumericType() {
-        return false;
-    }
-}

src/main/java/de/hsrm/compiler/Klang/types/Type.java

@@ -1,5 +1,12 @@
 package de.hsrm.compiler.Klang.types;
 
+import de.hsrm.compiler.Klang.Value;
+import de.hsrm.compiler.Klang.nodes.EnumDefinition;
+import de.hsrm.compiler.Klang.nodes.FunctionDefinition;
+import de.hsrm.compiler.Klang.nodes.StructDefinition;
+
+import java.util.Map;
+
 public abstract class Type {
 
   // Returns an instance of IntegerType
@@ -26,12 +33,13 @@ public abstract class Type {
       case "int": return getIntegerType();
       case "float": return getFloatType();
       case "null": return getNullType();
-      default: return new StructType(name);
+      default: return new NamedType(name);
     }
   }
 
   public abstract String getName();
   public abstract Type combine(Type that);
+  public abstract boolean valuesEqual(Value a, Value b);
   public abstract boolean isPrimitiveType();
   public abstract boolean isNumericType();
 }

src/main/java/de/hsrm/compiler/Klang/visitors/EvalVisitor.java

@@ -4,12 +4,7 @@ import java.util.HashMap;
 import java.util.Map;
 
 import de.hsrm.compiler.Klang.Value;
-import de.hsrm.compiler.Klang.nodes.Block;
+import de.hsrm.compiler.Klang.nodes.*;
-import de.hsrm.compiler.Klang.nodes.FunctionDefinition;
-import de.hsrm.compiler.Klang.nodes.Parameter;
-import de.hsrm.compiler.Klang.nodes.Program;
-import de.hsrm.compiler.Klang.nodes.StructDefinition;
-import de.hsrm.compiler.Klang.nodes.StructField;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
 import de.hsrm.compiler.Klang.nodes.loops.DoWhileLoop;
 import de.hsrm.compiler.Klang.nodes.loops.ForLoop;
@@ -51,25 +46,11 @@ public class EvalVisitor implements Visitor<Value> {
 
   @Override
   public Value visit(EqualityExpression e) {
-    Value lhs = e.lhs.welcome(this);
+    var lhs = e.lhs.welcome(this);
-    Value rhs = e.rhs.welcome(this);
+    var rhs = e.rhs.welcome(this);
-    Type resultType = Type.getBooleanType();
+    var combinedType = lhs.type.combine(rhs.type);
-    Type combineType = lhs.type.combine(rhs.type);
 
-    switch(combineType.getName()) {
+    return new Value(combinedType.valuesEqual(lhs, rhs), Type.getBooleanType());
-      case "bool": {
-        return new Value(lhs.asBoolean() == rhs.asBoolean(), resultType);
-      }
-      case "int": {
-        return new Value(lhs.asInteger() == rhs.asInteger(), resultType);
-      }
-      case "float": {
-        return new Value(lhs.asFloat() == rhs.asFloat(), resultType);
-      }
-      default: {
-        return new Value(lhs.asObject() == rhs.asObject(), resultType);
-      }
-    }
   }
 
   @Override
@@ -471,6 +452,16 @@ public class EvalVisitor implements Visitor<Value> {
     return null;
   }
 
+  @Override
+  public Value visit(EnumDefinition e) {
+    return null;
+  }
+
+  @Override
+  public Value visit(EnumValue e) {
+    return null;
+  }
+
   @Override
   public Value visit(StructDefinition e) {
     // We get these from a previous visitor
@@ -484,7 +475,7 @@ public class EvalVisitor implements Visitor<Value> {
   }
 
   @Override
-  public Value visit(StructFieldAccessExpression e) {
+  public Value visit(MemberAccessExpression e) {
     Value var = this.env.get(e.varName);
     Map<String, Value> struct = var.asStruct();
 
@@ -496,6 +487,11 @@ public class EvalVisitor implements Visitor<Value> {
     return currentValue;
   }
 
+  @Override
+  public Value visit(EnumAccessExpression e) {
+    return new Value(e.enumValueName, e.type);
+  }
+
   @Override
   public Value visit(ConstructorCall e) {
     StructDefinition structDef = this.structs.get(e.structName);

src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java

@@ -1,12 +1,6 @@
 package de.hsrm.compiler.Klang.visitors;
 
-import java.io.*;
+import de.hsrm.compiler.Klang.asm.ASM;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Set;
-import java.util.TreeSet;
-
 import de.hsrm.compiler.Klang.helper.Helper;
 import de.hsrm.compiler.Klang.nodes.*;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
@@ -16,48 +10,9 @@ import de.hsrm.compiler.Klang.nodes.loops.WhileLoop;
 import de.hsrm.compiler.Klang.nodes.statements.*;
 import de.hsrm.compiler.Klang.types.Type;
 
+import java.util.*;
+
 public class GenASM implements Visitor<Void> {
-
-  public static class ExWriter {
-    Writer w;
-    String indent = "";
-
-    void addIndent() {
-      indent = indent + "  ";
-    }
-
-    void subIndent() {
-      indent = indent.substring(2);
-    }
-
-    void nl() {
-      write("\n" + indent);
-    }
-
-    int lbl = 0;
-
-    int next() {
-      return lbl++;
-    }
-
-    public ExWriter(Writer w) {
-      this.w = w;
-    }
-
-    void lnwrite(Object o) {
-      nl();
-      write(o);
-    }
-
-    void write(Object o) {
-      try {
-        w.write(o + "");
-      } catch (IOException e) {
-        throw new RuntimeException(e);
-      }
-    }
-  }
-
   private class FloatWriter {
     private StringBuilder sb = new StringBuilder();
     private int id = -1;
@@ -104,7 +59,7 @@ public class GenASM implements Visitor<Void> {
     }
   }
 
-  public ExWriter ex;
+  private ASM asm;
   private FloatWriter fw = new FloatWriter();
   private String mainName;
   Map<String, Integer> env = new HashMap<>();
@@ -112,81 +67,81 @@ public class GenASM implements Visitor<Void> {
   Set<String> vars;
   String[] registers = { "%rdi", "%rsi", "%rdx", "%rcx", "%r8", "%r9" };
   String[] floatRegisters = { "%xmm0", "%xmm1", "%xmm2", "%xmm3", "%xmm4", "%xmm5", "%xmm6", "%xmm7" };
-  private int lCount = 0; // Invariante: lCount ist benutzt
+  private int lCount = 0; // Invariant: lCount is used
   private int currentFunctionStartLabel = 0;
   private Parameter[] currentFunctionParams;
 
-  private void intToFloat(String src, String dst) {
-    this.ex.write("    cvtsi2sd " + src + ", " + dst + "\n");
-  }
-
   private boolean prepareRegisters(Expression lhs, Expression rhs) {
     boolean lhsIsFloat = lhs.type.equals(Type.getFloatType());
     boolean rhsIsFloat = rhs.type.equals(Type.getFloatType());
     if (lhsIsFloat && rhsIsFloat) {
       lhs.welcome(this);
-      this.ex.write("    movsd %xmm0, %xmm2\n");
+      asm.mov("sd", "%xmm0", "%xmm2");
       rhs.welcome(this);
-      this.ex.write("    movsd %xmm0, %xmm1\n");
+      asm.mov("sd", "%xmm2", "%xmm0");
-      this.ex.write("    movsd %xmm2, %xmm0\n");
+      asm.mov("sd", "%xmm2", "%xmm0");
       return true;
     } else if (lhsIsFloat && !rhsIsFloat) {
       lhs.welcome(this);
       rhs.welcome(this);
-      this.intToFloat("%rax", "%xmm1");
+      asm.cvtsi2sd("%rax", "%xmm1");
       return true;
     } else if (!lhsIsFloat && rhsIsFloat) {
       lhs.welcome(this);
-      this.intToFloat("%rax", "%xmm2");
+      asm.cvtsi2sd("%rax", "%xmm2");
       rhs.welcome(this);
-      this.ex.write("    movsd %xmm0, %xmm1\n");
+      asm.mov("sd", "%xmm0", "%xmm1");
-      this.ex.write("    movsd %xmm2, %xmm0\n");
+      asm.mov("sd", "%xmm2", "%xmm0");
       return true;
     } else {
       lhs.welcome(this);
-      this.ex.write("    pushq %rax\n");
+      asm.push("q", "%rax");
       rhs.welcome(this);
-      this.ex.write("    movq %rax, %rbx\n");
+      asm.mov("q", "%rax", "%rbx");
-      this.ex.write("    popq %rax\n");
+      asm.pop("q", "%rax");
       return false;
     }
   }
 
-  public GenASM(ExWriter ex, String mainName, Map<String, StructDefinition> structs) {
+  public GenASM(String mainName, Map<String, StructDefinition> structs) {
-    this.ex = ex;
     this.mainName = mainName;
     this.structs = structs;
+    this.asm = new ASM();
   }
 
-  public GenASM(ExWriter ex, Map<String, StructDefinition> structs) {
+  public GenASM(Map<String, StructDefinition> structs) {
-    this(ex, "main", structs);
+    this("main", structs);
+  }
+
+  public String toAsm() {
+    return asm.toAsm();
   }
 
   @Override
   public Void visit(IntegerExpression e) {
-    this.ex.write("    movq $" + e.value + ", %rax\n");
+    asm.mov("q", e.value, "%rax");
     return null;
   }
 
   @Override
   public Void visit(FloatExpression e) {
     String floatLabel = fw.getFloat(e.value);
-    this.ex.write("    movsd " + floatLabel + "(%rip), %xmm0\n");
+    asm.mov("sd", floatLabel, "%rip", "%xmm0");
     return null;
   }
 
   @Override
   public Void visit(BooleanExpression e) {
-    this.ex.write("    movq $" + (e.value ? 1 : 0) + ", %rax\n");
+    asm.mov("q", e.value ? 1 : 0, "%rax");
     return null;
   }
 
   @Override
   public Void visit(Variable e) {
     if (e.type.equals(Type.getFloatType())) {
-      this.ex.write("    movsd " + this.env.get(e.name) + "(%rbp), %xmm0\n");
+      asm.mov("sd", this.env.get(e.name), "%rbp", "%xmm0");
     } else {
-      this.ex.write("    movq " + this.env.get(e.name) + "(%rbp), %rax\n");
+      asm.mov("q", this.env.get(e.name), "%rbp", "%rax");
     }
     return null;
   }
@@ -198,18 +153,18 @@ public class GenASM implements Visitor<Void> {
 
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    ucomisd %xmm1, %xmm0\n");
+      asm.ucomi("sd", "%xmm1", "xmm0");
     } else {
-      this.ex.write("    cmp %rbx, %rax\n");
+      asm.cmp("q", "%rbx", "%rax");
     }
-    this.ex.write("    je .L" + lblTrue + "\n");
+    asm.je(lblTrue);
     // false
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
-    this.ex.write(".L" + lblTrue + ":\n");
+    asm.label(lblTrue);
     // true
-    this.ex.write("   movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -220,18 +175,18 @@ public class GenASM implements Visitor<Void> {
 
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    ucomisd %xmm0, %xmm1\n");
+      asm.ucomi("sd", "%xmm0", "%xmm1");
     } else {
-      this.ex.write("    cmp %rax, %rbx\n");
+      asm.cmp("q", "%rax", "%rbx");
     }
-    this.ex.write("    jne .L" + lblTrue + "\n");
+    asm.jne(lblTrue);
     // false
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
-    this.ex.write(".L" + lblTrue + ":\n");
+    asm.label(lblTrue);
     // true
-    this.ex.write("   movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -242,18 +197,18 @@ public class GenASM implements Visitor<Void> {
 
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    ucomisd %xmm1, %xmm0\n");
+      asm.ucomi("sd", "%xmm1", "%xmm0");
     } else {
-      this.ex.write("    cmp %rbx, %rax\n");
+      asm.cmp("q", "%rbx", "%rax");
     }
-    this.ex.write("    jg .L" + lblTrue + "\n");
+    asm.jg(lblTrue);
     // false
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
-    this.ex.write(".L" + lblTrue + ":\n");
+    asm.label(lblTrue);
     // true
-    this.ex.write("   movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -264,18 +219,18 @@ public class GenASM implements Visitor<Void> {
 
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    ucomisd %xmm1, %xmm0\n");
+      asm.ucomi("sd", "%xmm1", "xmm0");
     } else {
-      this.ex.write("    cmp %rbx, %rax\n");
+      asm.cmp("q", "%rbx", "%rax");
     }
-    this.ex.write("    jge .L" + lblTrue + "\n");
+    asm.jge(lblTrue);
     // false
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
-    this.ex.write(".L" + lblTrue + ":\n");
+    asm.label(lblTrue);
     // true
-    this.ex.write("    movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -286,18 +241,18 @@ public class GenASM implements Visitor<Void> {
 
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    ucomisd %xmm1, %xmm0\n");
+      asm.ucomi("sd", "%xmm1", "%xmm0");
     } else {
-      this.ex.write("    cmp %rbx, %rax\n");
+      asm.cmp("q", "%rbx", "%rax");
     }
-    this.ex.write("    jl .L" + lblTrue + "\n");
+    asm.jl(lblTrue);
     // false
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
-    this.ex.write(".L" + lblTrue + ":\n");
+    asm.label(lblTrue);
     // true
-    this.ex.write("    movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -308,18 +263,18 @@ public class GenASM implements Visitor<Void> {
 
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    ucomisd %xmm1, %xmm0\n");
+      asm.ucomi("sd", "%xmm1", "%xmm0");
     } else {
-      this.ex.write("    cmp %rbx, %rax\n");
+      asm.cmp("q", "%rbx", "%rax");
     }
-    this.ex.write("    jle .L" + lblTrue + "\n");
+    asm.jle(lblTrue);
     // false
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
-    this.ex.write(".L" + lblTrue + ":\n");
+    asm.label(lblTrue);
     // true
-    this.ex.write("    movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -327,9 +282,9 @@ public class GenASM implements Visitor<Void> {
   public Void visit(AdditionExpression e) {
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    addsd %xmm1, %xmm0\n");
+      asm.add("sd", "%xmm1", "%xmm0");
     } else {
-      this.ex.write("    addq %rbx, %rax\n");
+      asm.add("q", "%rbx", "%rax");
     }
     return null;
   }
@@ -338,9 +293,9 @@ public class GenASM implements Visitor<Void> {
   public Void visit(SubstractionExpression e) {
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    subsd %xmm1, %xmm0\n");
+      asm.sub("sd", "%xmm1", "%xmm0");
     } else {
-      this.ex.write("    subq %rbx, %rax\n");
+      asm.sub("q", "%rbx", "%rax");
     }
     return null;
   }
@@ -349,9 +304,9 @@ public class GenASM implements Visitor<Void> {
   public Void visit(MultiplicationExpression e) {
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    mulsd %xmm1, %xmm0\n");
+      asm.mul("sd", "%xmm1", "%xmm0");
     } else {
-      this.ex.write("    imulq %rbx, %rax\n");
+      asm.imul("q", "%rbx", "%rax");
     }
     return null;
   }
@@ -360,10 +315,10 @@ public class GenASM implements Visitor<Void> {
   public Void visit(DivisionExpression e) {
     boolean isFloatOperation = this.prepareRegisters(e.lhs, e.rhs);
     if (isFloatOperation) {
-      this.ex.write("    divsd %xmm1, %xmm0\n");
+      asm.div("sd", "%xmm1", "%xmm0");
     } else {
-      this.ex.write("    cqto\n"); // sign extend rax into rdx since we're dealing with signed values
+      asm.cqto();
-      this.ex.write("    idiv %rbx\n"); // %rax/%rbx, quotient now in %rax
+      asm.idiv("q", "%rbx");
     }
     return null;
   }
@@ -371,13 +326,13 @@ public class GenASM implements Visitor<Void> {
   @Override
   public Void visit(ModuloExpression e) {
     e.lhs.welcome(this);
-    this.ex.write("    pushq %rax\n");
+    asm.push("q", "%rax");
     e.rhs.welcome(this);
-    this.ex.write("    movq %rax, %rbx\n");
+    asm.mov("q", "%rax", "%rbx");
-    this.ex.write("    popq %rax\n");
+    asm.pop("q", "%rax");
-    this.ex.write("    cqto\n"); // sign extend rax into rdx since we're dealing with signed values
+    asm.cqto();
-    this.ex.write("    idiv %rbx\n"); // %rax/%rbx, remainder now in %rdx
+    asm.idiv("q", "%rbx");
-    this.ex.write("    movq %rdx, %rax\n");
+    asm.mov("q", "%rdx", "%rax");
     return null;
   }
 
@@ -386,10 +341,10 @@ public class GenASM implements Visitor<Void> {
     e.lhs.welcome(this);
     if (e.lhs.type.equals(Type.getFloatType())) {
       String floatLabel = fw.getNegateFloat();
-      this.ex.write("    movsd " + floatLabel + "(%rip), %xmm1\n");
+      asm.mov("sd", floatLabel, "%rip", "%xmm1");
-      this.ex.write("    xorpd   %xmm1, %xmm0\n");
+      asm.xor("pd", "%xmm1", "%xmm0");
     } else {
-      this.ex.write("    neg %rax\n");
+      asm.neg("%rax");
     }
     return null;
   }
@@ -404,28 +359,28 @@ public class GenASM implements Visitor<Void> {
     // Wenn LHS != 0 bedeutet das true
     // also können wir direkt sagen dass das Ergebnis true ist
     e.lhs.welcome(this);
-    this.ex.write("    cmpq $0, %rax\n");
+    asm.cmp("q", 0, "%rax");
-    this.ex.write("    jne .L" + lblTrue + "\n");
+    asm.jne(lblTrue);
 
     // LHS war false, also werte RHS aus
     // Wenn RHS == 0 bedeutet das false,
     // also ist das Gesamtergebnis false
     e.rhs.welcome(this);
-    this.ex.write("    cmpq $0, %rax\n");
+    asm.cmp("q", 0, "%rax");
-    this.ex.write("    je .L" + lblFalse + "\n");
+    asm.je(lblFalse);
 
     // Die Expression wertet zu true aus
     // Springe am false Teil vorbei
-    this.ex.write(".L" + lblTrue + ":\n");
+    asm.label(lblTrue);
-    this.ex.write("    movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
 
     // Die Expressoin wertet zu false aus
-    this.ex.write(".L" + lblFalse + ":\n");
+    asm.label(lblFalse);
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
 
     // Das hier ist das ende
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -439,28 +394,28 @@ public class GenASM implements Visitor<Void> {
     // Wenn LHS == 0, bedeutet das false
     // also können wir direkt sagen dass das Ergebnis false ist
     e.lhs.welcome(this);
-    this.ex.write("    cmpq $0, %rax\n");
+    asm.cmp("q", 0, "%rax");
-    this.ex.write("    je .L" + lblFalse + "\n");
+    asm.je(lblFalse);
 
     // LHS war true, also werte RHS aus.
     // Wenn RHS == 0, bedeutet das false
     // also ist das Gesamtergebnis false
     e.rhs.welcome(this);
-    this.ex.write("    cmpq $0, %rax\n");
+    asm.cmp("q", 0, "%rax");
-    this.ex.write("    je .L" + lblFalse + "\n");
+    asm.je(lblFalse);
 
     // Die Expression wertet zu true aus
     // Springe am false Teil vorbei
-    this.ex.write(".L" + lblTrue + ":\n");
+    asm.label(lblTrue);
-    this.ex.write("    movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
 
     // Die Expressoin wertet zu false aus
-    this.ex.write(".L" + lblFalse + ":\n");
+    asm.label(lblFalse);
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
 
     // Das hier ist das ende
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -473,21 +428,21 @@ public class GenASM implements Visitor<Void> {
     // Wenn LHS != 0 bedeutet das true, also jumpe zum false Teil
     // Wenn nicht, falle durch zum true Teil
     e.lhs.welcome(this);
-    this.ex.write("    cmpq $0, %rax\n");
+    asm.cmp("q", 0, "%rax");
-    this.ex.write("    jne .L" + lblFalse + "\n");
+    asm.jne(lblFalse);
 
     // Hier ist das Ergebnis true
     // Springe am false Teil vorbei
-    this.ex.write("    movq $1, %rax\n");
+    asm.mov("q", 1, "%rax");
-    this.ex.write("    jmp .L" + lblEnd + "\n");
+    asm.jmp(lblEnd);
 
     // Hier ist das Ergebnis false
     // Falle zum Ende durch
-    this.ex.write(".L" + lblFalse + ":\n");
+    asm.label(lblFalse);
-    this.ex.write("movq $0, %rax\n");
+    asm.mov("q", 0, "%rax");
 
     // Hier ist das Ende
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -497,25 +452,25 @@ public class GenASM implements Visitor<Void> {
     int lblEnd = ++lCount;
     boolean hasElse = e.alt != null || e.elif != null;
     e.cond.welcome(this);
-    this.ex.write("    cmp $0, %rax\n");
+    asm.cmp("", 0, "%rax");
     // in case of cond evaluating to false, jump to else/elif
     // Jump to end if there is no else part, this saves a label declaration
     if (hasElse) {
-      this.ex.write("    jz .L" + lblElse + "\n");
+      asm.jz(lblElse);
     } else {
-      this.ex.write("    jz .L" + lblEnd + "\n");
+      asm.jz(lblEnd);
     }
     e.then.welcome(this);
     if (hasElse) {
-      this.ex.write("    jmp .L" + lblEnd + "\n");
+      asm.jmp(lblEnd);
-      this.ex.write(".L" + lblElse + ":\n");
+      asm.label(lblElse);
       if (e.alt != null) {
         e.alt.welcome(this);
       } else {
         e.elif.welcome(this);
       }
     }
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
@@ -523,24 +478,24 @@ public class GenASM implements Visitor<Void> {
   public Void visit(WhileLoop e) {
     int lblCond = ++lCount;
     int lblEnd = ++lCount;
-    this.ex.write(".L" + lblCond + ":\n");
+    asm.label(lblCond);
     e.cond.welcome(this);
-    this.ex.write("    cmp $0, %rax\n");
+    asm.cmp("", 0, "%rax");
-    this.ex.write("    jz .L" + lblEnd + "\n");
+    asm.jz(lblEnd);
     e.block.welcome(this);
-    this.ex.write("    jmp .L" + lblCond + "\n");
+    asm.jmp(lblCond);
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
     return null;
   }
 
   @Override
   public Void visit(DoWhileLoop e) {
     int lblStart = ++lCount;
-    this.ex.write(".L" + lblStart + ":\n");
+    asm.label(lblStart);
     e.block.welcome(this);
     e.cond.welcome(this);
-    this.ex.write("    cmp $0, %rax\n");
+    asm.cmp("", 0, "%rax");
-    this.ex.write("    jnz .L" + lblStart + "\n");
+    asm.jnz(lblStart);
     return null;
   }
 
@@ -549,15 +504,14 @@ public class GenASM implements Visitor<Void> {
     int lblStart = ++lCount;
     int lblEnd = ++lCount;
     e.init.welcome(this);
-    this.ex.write(".L" + lblStart + ":\n");
+    asm.label(lblStart);
     e.condition.welcome(this);
-    this.ex.write("    cmp $0, %rax\n");
+    asm.cmp("", 0, "%rax");
-    this.ex.write("    jz .L" + lblEnd + "\n");
+    asm.jz(lblEnd);
     e.block.welcome(this);
     e.step.welcome(this);
-    this.ex.write("    jmp .L" + lblStart + "\n");
+    asm.jmp(lblStart);
-    this.ex.write(".L" + lblEnd + ":\n");
+    asm.label(lblEnd);
-
     return null;
   }
 
@@ -568,12 +522,12 @@ public class GenASM implements Visitor<Void> {
     if (e.expression != null) {
       e.expression.welcome(this);
       int offset = this.env.get(e.name);
-      
+
       if (e.expression.type.equals(Type.getFloatType())) {
-        this.ex.write("    movq %xmm0, %rax\n");
+        asm.mov("q", "%xmm0", "%rax");
       }
 
-      this.ex.write("    movq %rax, " + offset + "(%rbp)\n");
+      asm.mov("q", "%rax", offset, "%rbp");
     }
     return null;
   }
@@ -586,20 +540,20 @@ public class GenASM implements Visitor<Void> {
     // Determine where the result of this expression was placed into
     // and move it onto the stack from there
     if (e.expression.type.equals(Type.getFloatType())) {
-      this.ex.write("    movq %xmm0, " + offset + "(%rbp)\n");
+      asm.mov("q", "%xmm0", offset, "%rbp");
     } else {
-      this.ex.write("    movq %rax, " + offset + "(%rbp)\n");
+      asm.mov("q", "%rax", offset, "%rbp");
     }
-    
+
     return null;
   }
 
   @Override
   public Void visit(ReturnStatement e) {
     e.expression.welcome(this);
-    this.ex.write("    movq %rbp, %rsp\n");
+    asm.mov("q", "%rbp", "%rsp");
-    this.ex.write("    popq %rbp\n");
+    asm.pop("q", "%rbp");
-    this.ex.write("    ret\n");
+    asm.ret();
     return null;
   }
 
@@ -613,15 +567,20 @@ public class GenASM implements Visitor<Void> {
 
   @Override
   public Void visit(FunctionDefinition e) {
+    // If the user chooses "main" as one of his function names then
+    // rename it and hope that they didn't use the renamed function name
+    // as well :D
+    if (e.name.equals("main")) {
+      e.name = "main_by_user";
+    }
+
     int lblStart = ++lCount;
     this.currentFunctionStartLabel = lblStart;
     this.currentFunctionParams = e.parameters;
-    this.ex.write(".globl " + e.name + "\n");
+    asm.functionHead(e.name);
-    this.ex.write(".type " + e.name + ", @function\n");
+    asm.push("q", "%rbp");
-    this.ex.write(e.name + ":\n");
+    asm.mov("q", "%rsp", "%rbp");
-    this.ex.write("    pushq %rbp\n");
+    asm.label(lblStart);
-    this.ex.write("    movq %rsp, %rbp\n");
-    this.ex.write(".L" + lblStart + ":\n");
 
     // hole die anzahl der lokalen variablen
     this.vars = new TreeSet<String>();
@@ -661,19 +620,19 @@ public class GenASM implements Visitor<Void> {
         }
       }
     }
-    
+
     offset = 0;
     ri = 0;
     fi = 0;
     for (var param: registerParameters) {
       if (param.type.equals(Type.getFloatType())) {
-        this.ex.write("    movq "+ this.floatRegisters[fi] + ", %rax\n");
+        asm.mov("q", this.floatRegisters[fi], "%rax");
-        this.ex.write("    pushq %rax\n");
+        asm.push("q", "%rax");
         offset -= 8;
         this.env.put(param.name, offset); // negative, liegt unter aktuellem BP
         fi++;
       } else {
-        this.ex.write("    pushq " + this.registers[ri] + "\n");
+        asm.push("q", this.registers[ri]);
         offset -= 8;
         this.env.put(param.name, offset); // negative, liegt unter aktuellem BP
         ri++;
@@ -683,7 +642,7 @@ public class GenASM implements Visitor<Void> {
     // Reserviere Platz auf dem Stack für jede lokale variable
     for (String lok_var : vars) {
       offset -= 8;
-      this.ex.write("    pushq $0\n");
+      asm.push("q", 0);
       this.env.put(lok_var, offset);
     }
 
@@ -700,18 +659,18 @@ public class GenASM implements Visitor<Void> {
         e.arguments[i].welcome(this);
 
         if (e.arguments[i].type.equals(Type.getFloatType())) {
-          this.ex.write("    movq %xmm0, %rax\n");
+          asm.mov("q", "%xmm0", "%rax0");
         }
 
-        this.ex.write("    pushq %rax\n");
+        asm.push("q", "%rax");
       }
 
       // push args into local var locations, last arg is ontop of the stack
       for (int i = e.arguments.length - 1; i >= 0; i--) {
-        this.ex.write("    popq " + this.env.get(this.currentFunctionParams[i].name) + "(%rbp)\n");
+        asm.pop("q", this.env.get(this.currentFunctionParams[i].name) + "(%rbp)");
       }
 
-      this.ex.write("    jmp .L" + this.currentFunctionStartLabel + "\n");
+      asm.jmp(this.currentFunctionStartLabel);
       return null;
     }
 
@@ -724,12 +683,12 @@ public class GenASM implements Visitor<Void> {
       // Mapping arguments index -> all purpose registers index
       int[] rIdxs = new int[this.registers.length];
       int ri = -1;
-      
+
       // Mapping arguments index -> stack
       ArrayList<Integer> stackIdxs = new ArrayList<Integer>();
 
       // Go through arguments
-      // sort them into the memory regions they go when being passed to functions 
+      // sort them into the memory regions they go when being passed to functions
       for (int i = 0; i < e.arguments.length; i++) {
         var arg = e.arguments[i];
         if (arg.type.equals(Type.getFloatType())) {
@@ -757,10 +716,10 @@ public class GenASM implements Visitor<Void> {
       for (var arg : e.arguments) {
         arg.welcome(this);
         if (arg.type.equals(Type.getFloatType())) {
-          this.ex.write("    movq %xmm0, %rax\n");
+          asm.mov("q", "%xmm0", "%rax");
-          this.ex.write("    pushq %rax\n");
+          asm.push("q", "%rax");
         } else {
-          this.ex.write("    pushq %rax\n");
+          asm.push("q", "%rax");
         }
       }
 
@@ -768,14 +727,14 @@ public class GenASM implements Visitor<Void> {
       for (int i = 0; i <= fi; i++) {
         int indexInArguments = xmmIdxs[i];
         int rspOffset = (((e.arguments.length - indexInArguments) - 1) * 8);
-        this.ex.write("    movsd " + rspOffset + "(%rsp),  " + this.floatRegisters[i] + "\n");
+        asm.mov("sd", rspOffset, "%rsp", this.floatRegisters[i]);
       }
 
       // Move primitives from stack to all purpose registers
       for (int i = 0; i <= ri; i++) {
         int indexInArguments = rIdxs[i];
         int rspOffset = (((e.arguments.length - indexInArguments) - 1) * 8);
-        this.ex.write("    movq " + rspOffset + "(%rsp),  " + this.registers[i] + "\n");
+        asm.mov("q", rspOffset, "%rsp", this.registers[i]);
       }
 
       // Move everything else from a higher stack position to our stack frame start
@@ -784,49 +743,55 @@ public class GenASM implements Visitor<Void> {
         stackStartOffset -= 8;
         int indexInArguments = stackIdxs.get(i);
         int rspOffset = (((e.arguments.length - indexInArguments) - 1) * 8);
-        this.ex.write("    movq " + rspOffset + "(%rsp), %rax\n");
+        asm.mov("q", rspOffset, "%rsp", "%rax");
-        this.ex.write("    movq %rax, " + stackStartOffset + "(%rsp)\n");
+        asm.mov("q", "%rax", stackStartOffset, "%rsp");
       }
 
       // Rescue RSP
-      this.ex.write("    addq  $" + stackStartOffset + ", %rsp\n");
+      asm.add("q", stackStartOffset, "%rsp");
     }
 
-    this.ex.write("    call " + e.name + "\n");
+    // We rename a function name if it is "main"
+    asm.call(e.name.equals("main") ? "main_by_user": e.name);
     return null;
   }
 
   @Override
   public Void visit(Program e) {
-    this.ex.write(".text\n");
+    asm.text(".text");
     for (var func : e.funcs) {
       func.welcome(this);
-      this.ex.write("\n");
+      asm.newline();
     }
-    this.ex.write(".globl " + mainName + "\n");
+    asm.functionHead(mainName);
-    this.ex.write(".type " + mainName + ", @function\n");
+    asm.push("q", "%rbp");
-    this.ex.write(mainName + ":\n");
+    asm.mov("q", "%rsp", "%rbp");
-    this.ex.write("    pushq %rbp\n");
-    this.ex.write("    movq %rsp, %rbp\n");
     e.expression.welcome(this);
+    asm.mov("q", "%rbp", "%rsp");
+    asm.pop("q", "%rbp");
+    asm.ret();
 
-    this.ex.write("    movq %rbp, %rsp\n");
+    asm.text(fw.getFloatSection());
-    this.ex.write("    popq %rbp\n");
-    this.ex.write("    ret\n");
-
-    // PRINT FLOATS HERE
-    this.ex.write("\n");
-    this.ex.write(fw.getFloatSection());
     return null;
   }
 
   @Override
   public Void visit(Parameter e) {
-    // The work for a paremeter node is implement
+    // The work for a parameter node is implement
     // in the function definition visitor
     return null;
   }
 
+  @Override
+  public Void visit(EnumDefinition e) {
+    return null;
+  }
+
+  @Override
+  public Void visit(EnumValue e) {
+    return null;
+  }
+
   @Override
   public Void visit(StructDefinition e) {
     // We get these from a previous visitor
@@ -840,31 +805,39 @@ public class GenASM implements Visitor<Void> {
   }
 
   @Override
-  public Void visit(StructFieldAccessExpression e) {
+  public Void visit(MemberAccessExpression e) {
     var structDef = this.structs.get(e.structName);
     int offset = this.env.get(e.varName);
 
     // move struct address into rax
-    this.ex.write("    movq " + offset + "(%rbp), %rax\n");
+    asm.mov("q", offset, "%rbp", "%rax");
 
     // "follow" the first path element by moving the referenced value into rax
-    this.ex.write("    movq " + Helper.getFieldOffset(structDef, e.path[0]) + "(%rax), %rax\n");
+    asm.mov("q", Helper.getFieldOffset(structDef, e.path[0]), "%rax", "%rax");
     for  (int i = 1; i < e.path.length; i++) {
       // "follow" the current path element
       structDef = this.structs.get(structDef.fields[Helper.getFieldIndex(structDef, e.path[i - 1])].type.getName());
-      this.ex.write("    movq " + Helper.getFieldOffset(structDef, e.path[i]) + "(%rax), %rax\n");
+      asm.mov("q", Helper.getFieldOffset(structDef, e.path[i]), "%rax", "%rax");
     }
 
     // desired value now in rax
 
     // push rax to xmm0 if the result type is a float
     if (e.type.equals(Type.getFloatType())) {
-      this.ex.write("    movq %rax, %xmm0\n");
+      asm.mov("q", "%rax", "%xmm0");
     }
 
     return null;
   }
 
+  @Override
+  public Void visit(EnumAccessExpression e) {
+    // Since the access to an enum simply results in an integer (i.e. the index
+    // of the enum value), we can just let IntegerExpression handle the expected behaviour.
+    new IntegerExpression(e.enumValue.index).welcome(this);
+    return null;
+  }
+
   @Override
   public Void visit(ConstructorCall e) {
     // push arguments onto the stack
@@ -873,20 +846,20 @@ public class GenASM implements Visitor<Void> {
 
       // move float values from xmm0 to rax first
       if (arg.type.equals(Type.getFloatType())) {
-        this.ex.write("    movq %xmm0, %rax\n");
+        asm.mov("q", "%xmm0", "%rax");
       }
 
-      this.ex.write("    pushq %rax\n");
+      asm.push("q", "%rax");
     }
 
     // allocate heap memory by calling malloc
     var structDef = this.structs.get(e.structName);
-    this.ex.write("    movl $" + Helper.getFieldSizeBytes(structDef) + ", %edi\n");
+    asm.mov("l", Helper.getFieldSizeBytes(structDef), "%edi");
-    this.ex.write("    call malloc@PLT\n"); // struct address now in rax
+    asm.call("malloc@PLT");
 
     // push args into struct memory, last arg is ontop of the stack
     for (int i = e.args.length - 1; i >= 0; i--) {
-      this.ex.write("    popq " + Helper.getFieldOffset(structDef, i) + "(%rax)\n");
+      asm.pop("q", Helper.getFieldOffset(structDef, i) + "(%rax)");
     }
 
     return null;
@@ -894,14 +867,14 @@ public class GenASM implements Visitor<Void> {
 
   @Override
   public Void visit(NullExpression e) {
-    this.ex.write("    movq $0, %rax\n");
+    asm.mov("q", 0 , "%rax");
     return null;
   }
 
   @Override
   public Void visit(DestructorCall e) {
-    this.ex.write("    movq " +this.env.get(e.name) + "(%rbp), %rdi\n");
+    asm.mov("q", this.env.get(e.name), "%rbp", "%rdi");
-    this.ex.write("    call free@PLT\n");
+    asm.call("free@PLT");
     return null;
   }
 
@@ -915,25 +888,25 @@ public class GenASM implements Visitor<Void> {
 
     // Move it from xmm0 rax if its a flaot
     if (e.expression.type.equals(Type.getFloatType())) {
-      this.ex.write("    movq %xmm0, %rax\n");
+      asm.mov("q", "%xmm0", "%rax");
     }
 
     // Push the expression onto the stack
-    this.ex.write("    pushq %rax\n");
+    asm.push("q", "%rax");
 
     // move struct address into rax
-    this.ex.write("    movq " + offset + "(%rbp), %rax\n");
+    asm.mov("q", offset, "%rbp", "%rax");
 
-    // If there are at least two elements in the path, 
+    // If there are at least two elements in the path,
     // move the address of the next referenced struct into rax
     for  (int i = 1; i < e.path.length - 1; i++) {
       structDef = this.structs.get(structDef.fields[Helper.getFieldIndex(structDef, e.path[i - 1])].type.getName());
-      this.ex.write("    movq " + Helper.getFieldOffset(structDef, e.path[i]) + "(%rax), %rax\n");
+      asm.mov("q",  Helper.getFieldOffset(structDef, e.path[i]), "%rax", "%rax");
     }
 
     // pop the expression that is ontop of the stack into the field of the struct that has to be updated
-    this.ex.write("    popq " + Helper.getFieldOffset(structDef, fieldNameToUpdate) + "(%rax)\n");
+    asm.pop("q", Helper.getFieldOffset(structDef, fieldNameToUpdate) + "(%rax)");
-    this.ex.write("    movq $0, %rax\n"); // clear rax sind an assignment has no result
+    asm.mov("q", 0 , "%rax"); // clear rax since an assignment has no result
 
     return null;
   }

src/main/java/de/hsrm/compiler/Klang/visitors/GetVars.java

@@ -234,6 +234,16 @@ class GetVars implements Visitor<Void> {
     return null;
   }
 
+  @Override
+  public Void visit(EnumDefinition e) {
+    return null;
+  }
+
+  @Override
+  public Void visit(EnumValue e) {
+    return null;
+  }
+
   @Override
   public Void visit(StructDefinition e) {
     return null;
@@ -245,7 +255,12 @@ class GetVars implements Visitor<Void> {
   }
 
   @Override
-  public Void visit(StructFieldAccessExpression e) {
+  public Void visit(MemberAccessExpression e) {
+    return null;
+  }
+
+  @Override
+  public Void visit(EnumAccessExpression e) {
     return null;
   }
 

src/main/java/de/hsrm/compiler/Klang/visitors/PrettyPrintVisitor.java

@@ -68,6 +68,12 @@ public class PrettyPrintVisitor implements Visitor<Void> {
       ex.nl();
     }
 
+    for (var enumDef: e.enums.values()) {
+      enumDef.welcome(this);
+      ex.nl();
+      ex.nl();
+    }
+
     e.expression.welcome(this);
     ex.write(";");
     return null;
@@ -377,6 +383,28 @@ public class PrettyPrintVisitor implements Visitor<Void> {
     return null;
   }
 
+  @Override
+  public Void visit(EnumDefinition e) {
+    ex.write("enum " + e.name + " { ");
+    var first = true;
+    for(var enumValue: e.enums) {
+      if (!first) {
+        ex.write(", ");
+      } else {
+        first = false;
+      }
+      enumValue.welcome(this);
+    }
+    ex.write(" }");
+    return null;
+  }
+
+  @Override
+  public Void visit(EnumValue e) {
+    ex.write(e.value);
+    return null;
+  }
+
   @Override
   public Void visit(StructDefinition e) {
     ex.write("struct " + e.name + " {");
@@ -398,7 +426,7 @@ public class PrettyPrintVisitor implements Visitor<Void> {
   }
 
   @Override
-  public Void visit(StructFieldAccessExpression e) {
+  public Void visit(MemberAccessExpression e) {
     ex.write(e.varName);
     for (int i = 0; i < e.path.length; i++) {
       ex.write(".");
@@ -407,6 +435,15 @@ public class PrettyPrintVisitor implements Visitor<Void> {
     return null;
   }
 
+  @Override
+  public Void visit(EnumAccessExpression e) {
+    ex.write(e.enumName);
+    ex.write(".");
+    ex.write(e.enumValueName);
+
+    return null;
+  }
+
   @Override
   public Void visit(ConstructorCall e) {
     ex.write("create " + e.structName + "(");

src/main/java/de/hsrm/compiler/Klang/visitors/Visitor.java

@@ -1,11 +1,6 @@
 package de.hsrm.compiler.Klang.visitors;
 
-import de.hsrm.compiler.Klang.nodes.Block;
+import de.hsrm.compiler.Klang.nodes.*;
-import de.hsrm.compiler.Klang.nodes.FunctionDefinition;
-import de.hsrm.compiler.Klang.nodes.Parameter;
-import de.hsrm.compiler.Klang.nodes.Program;
-import de.hsrm.compiler.Klang.nodes.StructDefinition;
-import de.hsrm.compiler.Klang.nodes.StructField;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
 import de.hsrm.compiler.Klang.nodes.loops.*;
 import de.hsrm.compiler.Klang.nodes.statements.*;
@@ -42,9 +37,12 @@ public interface Visitor<R> {
     R visit(FunctionCall e);
     R visit(Program e);
     R visit(Parameter e);
+    R visit(EnumDefinition e);
+    R visit(EnumValue e);
     R visit(StructDefinition e);
     R visit(StructField e);
-    R visit(StructFieldAccessExpression e);
+    R visit(MemberAccessExpression e);
+    R visit(EnumAccessExpression e);
     R visit(ConstructorCall e);
     R visit(NullExpression e);
     R visit(DestructorCall e);

src/test/java/AndTest.java

@@ -12,7 +12,8 @@ public class AndTest {
         ParseTree tree = Helper.prepareParser("function foo(): bool { return 1 && 2; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:30 && is only defined for bool.", e.getMessage());

src/test/java/ConstructorCallTest.java

@@ -13,7 +13,8 @@ public class ConstructorCallTest {
         ParseTree tree = Helper.prepareParser("struct bar { a: int; } function foo(): bar { return create schwurbel(1); } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:52 Struct with name \"schwurbel\" not defined.", e.getMessage());
@@ -24,7 +25,8 @@ public class ConstructorCallTest {
         ParseTree tree = Helper.prepareParser("struct bar { a: int; } function foo(): bar { return create bar(1, false); } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:52 Struct \"bar\" defined 1 fields, but got 2 constructor parameters.", e.getMessage());
@@ -35,7 +37,8 @@ public class ConstructorCallTest {
         ParseTree tree = Helper.prepareParser("struct bar { a: int; } function foo(): bar { return create bar(false); } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:63 argument 0 Type missmatch: cannot combine bool and int", e.getMessage());

src/test/java/DestroyStatementTest.java

@@ -13,7 +13,8 @@ public class DestroyStatementTest {
         ParseTree tree = Helper.prepareParser("struct bar { a: int; } function foo(): int { destroy x; return 1; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:45 Variable with name \"x\" not defined.", e.getMessage());

src/test/java/FieldAssignmentTest.java

@@ -13,7 +13,8 @@ public class FieldAssignmentTest {
         ParseTree tree = Helper.prepareParser("struct test { a: int; } function foo(): int { str.a = 1; return 1; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:46 Variable with name str not defined.", e.getMessage());
@@ -24,7 +25,8 @@ public class FieldAssignmentTest {
         ParseTree tree = Helper.prepareParser("struct test { a: int; } function foo(): int { let x: int = 0; x.a = 0; return 1; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:62 Variable must reference a struct but references int.", e.getMessage());

src/test/java/FunctionCallTest.java

@@ -13,7 +13,8 @@ public class FunctionCallTest {
         ParseTree tree = Helper.prepareParser("function foo(): int { return 1; } bar();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:34 Function with name \"bar\" not defined.", e.getMessage());
@@ -24,7 +25,8 @@ public class FunctionCallTest {
         ParseTree tree = Helper.prepareParser("function foo(): int { return 1; } foo(5);");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:34 Function \"foo\" expects 0 parameters, but got 1.", e.getMessage());
@@ -35,7 +37,8 @@ public class FunctionCallTest {
         ParseTree tree = Helper.prepareParser("function foo(x: int): int { return x; } foo(false);");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:40 argument 0 Expected int but got: bool", e.getMessage());

src/test/java/FunctionDefinitionTest.java

@@ -1,32 +1,95 @@
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import de.hsrm.compiler.Klang.ContextAnalysis;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-import org.antlr.v4.runtime.tree.ParseTree;
 import org.junit.jupiter.api.Test;
 
-import de.hsrm.compiler.Klang.ContextAnalysis;
+import static org.junit.jupiter.api.Assertions.*;
 
 public class FunctionDefinitionTest {
 
     @Test
-    void typeNotDefined() {
+    void shouldNotThrowIfReturnTypeIsReferringToAnEnum() {
-        ParseTree tree = Helper.prepareParser("function foo(): schwurbel { return 1; } foo();");
+        // given
-        var funcs = Helper.getFuncs(tree);
+        var tree = Helper.prepareParser(" enum bar {A,B,C} function foo(a: int): bar { return bar.A; } foo(1);");
-        var structs = Helper.getStructs(tree);
+        var ctxAnal = new ContextAnalysis(
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+                Helper.getFuncs(tree),
-        
+                Helper.getStructs(tree),
-        Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+                Helper.getEnums(tree)
-        assertEquals("Error in line 1:0 Type schwurbel not defined.", e.getMessage());
+        );
+
+        // when / then
+        assertDoesNotThrow(() -> ctxAnal.visit(tree));
     }
 
     @Test
-    void noReturnExpression() {
+    void shouldNotThrowIfParameterTypeIsReferringToAnEnum() {
-        ParseTree tree = Helper.prepareParser("function foo(): int { let x: int; x = 0; } foo();");
+        // given
-        var funcs = Helper.getFuncs(tree);
+        var tree = Helper.prepareParser(" enum bar {A,B,C} function foo(a: bar): int { return 1; } foo(bar.A);");
-        var structs = Helper.getStructs(tree);
+        var ctxAnal = new ContextAnalysis(
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+                Helper.getFuncs(tree),
-        
+                Helper.getStructs(tree),
-        Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+                Helper.getEnums(tree)
-        assertEquals("Error in line 1:0 Function foo has to return something of type int.", e.getMessage());
+        );
+
+        // when / then
+        assertDoesNotThrow(() -> ctxAnal.visit(tree));
+    }
+
+    @Test
+    void shouldThrowExceptionIfParameterTypeIsNotDefined() {
+        // given
+        var tree = Helper.prepareParser("function foo(a: schwurbel): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:14 Type schwurbel not defined.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfReturnTypeIsNotDefined() {
+        // given
+        var tree = Helper.prepareParser("function foo(): schwurbel { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:14 Type schwurbel not defined.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfReturnStatementIsMissing() {
+        // given
+        var tree = Helper.prepareParser("function foo(): int { let x: int; x = 0; } foo();");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:20 Function foo has to return something of type int.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfParameterNameMatchesEnumName() {
+        // given
+        var tree = Helper.prepareParser("enum Bar { A, B } function foo(Bar: int): int { return 1; } foo(1);");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:31 Parameter name Bar duplicates an enum of the same name.", e.getMessage());
     }
 }

src/test/java/Helper.java

@@ -16,21 +16,21 @@ public class Helper {
         return parser.parse();
     }
 
-    public static Map<String, FunctionInformation> getFuncs(ParseTree tree) {
+    public static Map<String, FunctionDefinition> getFuncs(ParseTree tree) {
-        var functionDefinitions = new HashMap<String, FunctionInformation>();
+        var functionDefinitions = new HashMap<String, FunctionDefinition>();
-        new GetFunctions(functionDefinitions).visit(tree);
+        new GetDefinitions(functionDefinitions, new HashMap<>(), new HashMap<>()).visit(tree);
         return functionDefinitions;
     }
 
-    public static Set<String> getStructNames(ParseTree tree) {
-        var structNames = new HashSet<String>();
-        new GetStructNames(structNames).visit(tree);
-        return structNames;
-    }
-
     public static Map<String, StructDefinition> getStructs(ParseTree tree) {
         var structs = new HashMap<String, StructDefinition>();
-        new GetStructs(getStructNames(tree), structs).visit(tree);
+        new GetDefinitions(new HashMap<>(), structs, new HashMap<>()).visit(tree);
         return structs;
     }
+
+    public static Map<String, EnumDefinition> getEnums(ParseTree tree) {
+        var enums = new HashMap<String, EnumDefinition>();
+        new GetDefinitions(new HashMap<>(), new HashMap<>(), enums).visit(tree);
+        return enums;
+    }
 }

src/test/java/ModuloTest.java

@@ -12,7 +12,8 @@ public class ModuloTest {
         ParseTree tree = Helper.prepareParser("function foo(): float { return 1.0 % 2.3; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:31 Only integers are allowed for modulo.", e.getMessage());

src/test/java/OrTest.java

@@ -13,7 +13,8 @@ public class OrTest {
         ParseTree tree = Helper.prepareParser("function foo(): bool { return 1 || 2; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:30 || is only defined for bool.", e.getMessage());

src/test/java/ParameterTest.java

@@ -1,14 +0,0 @@
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-import org.antlr.v4.runtime.tree.ParseTree;
-import org.junit.jupiter.api.Test;
-
-public class ParameterTest {
-    @Test
-    void typeNotDefined() {
-        ParseTree tree = Helper.prepareParser("struct test { a: schwurbel; } function foo(): int { return 1; } foo();");
-        Exception e = assertThrows(RuntimeException.class, () -> Helper.getStructs(tree));
-        assertEquals("Error in line 1:14 Type schwurbel not defined.", e.getMessage());
-    }
-}

src/test/java/StructDefinitionTest.java

@@ -0,0 +1,94 @@
+import de.hsrm.compiler.Klang.ContextAnalysis;
+import de.hsrm.compiler.Klang.GetDefinitions;
+import org.junit.jupiter.api.Test;
+
+import java.util.HashMap;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class StructDefinitionTest {
+    @Test
+    void shouldNotThrowIfStructIsWellDefined() {
+        // given
+        var tree = Helper.prepareParser("struct test { a: int; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        assertDoesNotThrow(() -> ctxAnal.visit(tree));
+    }
+
+    @Test
+    void shouldNotThrowIfStructFieldTypeIsReferringToEnum() {
+        // given
+        var tree = Helper.prepareParser("struct test { a: bar; } enum bar {A,B,C} function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        assertDoesNotThrow(() -> ctxAnal.visit(tree));
+    }
+
+    @Test
+    void shouldNotThrowIfStructFieldTypeIsReferringToStruct() {
+        // given
+        var tree = Helper.prepareParser("struct a { hello: int; } struct b { world: a; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        assertDoesNotThrow(() -> ctxAnal.visit(tree));
+    }
+
+    @Test
+    void shouldThrowExceptionIfStructFieldNameShadowsAStruct() {
+        // given
+        var tree = Helper.prepareParser("struct bar { a: int; } struct baz { bar: int; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:36 Struct field name bar shadows a struct of the same name.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfStructFieldNameShadowsAnEnum() {
+        // given
+        var tree = Helper.prepareParser("enum bar { A, B } struct baz { bar: int; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:31 Struct field name bar shadows an enum of the same name.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfStructFieldTypeIsNotDefined() {
+        // given
+        var tree = Helper.prepareParser("struct test { a: schwurbel; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:14 Type schwurbel not defined.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfStructFieldTypeIsReferringToAFunction() {
+        // given
+        var tree = Helper.prepareParser("struct test { a: foo; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:14 Type foo not defined.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfStructFieldNameIsDuplicated() {
+        // given
+        var tree = Helper.prepareParser("struct test { a: int; a: bool; } function foo(): int { return 1; } foo();");
+        var getDefs = new GetDefinitions(new HashMap<>(), new HashMap<>(), new HashMap<>());
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> getDefs.visit(tree));
+        assertEquals("Error in line 1:22 Duplicate struct field a in struct test.", e.getMessage());
+    }
+}

src/test/java/StructFieldAccessTest.java

@@ -12,7 +12,8 @@ public class StructFieldAccessTest {
         ParseTree tree = Helper.prepareParser("struct test { a: int; } function foo(): int { return str.a; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:53 Variable with name str not defined.", e.getMessage());
@@ -23,7 +24,8 @@ public class StructFieldAccessTest {
         ParseTree tree = Helper.prepareParser("struct test { a: int; } function foo(): int { let x: int = 0; return x.a; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:69 Variable must reference a struct but references int.", e.getMessage());

src/test/java/VariableAssignmentTest.java

@@ -13,7 +13,8 @@ public class VariableAssignmentTest {
         ParseTree tree = Helper.prepareParser("function foo(): int { x = 1; return 1; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:22 Variable with name \"x\" not defined.", e.getMessage());

src/test/java/VariableDeclarationTest.java

@@ -1,32 +1,109 @@
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import de.hsrm.compiler.Klang.ContextAnalysis;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-import org.antlr.v4.runtime.tree.ParseTree;
 import org.junit.jupiter.api.Test;
 
-import de.hsrm.compiler.Klang.ContextAnalysis;
+import static org.junit.jupiter.api.Assertions.*;
 
 public class VariableDeclarationTest {
     @Test
-    void typeNotDefined() {
+    void shouldNotThrowIfDeclaredTypeIsAStruct() {
-        ParseTree tree = Helper.prepareParser("function foo(): int { let X: unk; return 1; } foo();");
+        // given
-        var funcs = Helper.getFuncs(tree);
+        var tree = Helper.prepareParser("struct bar { a: int; } function foo(): int { let a: bar; return 1; } foo();");
-        var structs = Helper.getStructs(tree);
+        var ctxAnal = new ContextAnalysis(
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+                Helper.getFuncs(tree),
-        
+                Helper.getStructs(tree),
-        Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        assertDoesNotThrow(() -> ctxAnal.visit(tree));
+    }
+
+    @Test
+    void shouldNotThrowIfDeclaredTypeIsAnEnum() {
+        // given
+        var tree = Helper.prepareParser("enum bar { A, B } function foo(): int { let a: bar = bar.A; return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        assertDoesNotThrow(() -> ctxAnal.visit(tree));
+    }
+
+    @Test
+    void shouldThrowExceptionIfDeclaredNameShadowsEnumName() {
+        // given
+        var tree = Helper.prepareParser("enum bar { A, B } function foo(): int { let bar: int; return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:40 Variable name bar shadows an enum of the same name.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfDeclaredNameShadowsStruct() {
+        // given
+        var tree = Helper.prepareParser("struct bar { a: int; } function foo(): int { let bar: int; return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:45 Variable name bar shadows a struct of the same name.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfDeclaredTypeIsNotDefined() {
+        // given
+        var tree = Helper.prepareParser("function foo(): int { let X: unk; return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:22 Type unk not defined.", e.getMessage());
     }
 
     @Test
-    void variableRedeclaration()
+    void shouldThrowExceptionIfVariableIsRedeclared() {
-    {
+        // given
-        ParseTree tree = Helper.prepareParser("function foo(): int { let x: int; let x: bool; return 1; } foo();");
+        var tree = Helper.prepareParser("function foo(): int { let x: int; let x: bool; return 1; } foo();");
-        var funcs = Helper.getFuncs(tree);
+        var ctxAnal = new ContextAnalysis(
-        var structs = Helper.getStructs(tree);
+                Helper.getFuncs(tree),
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+                Helper.getStructs(tree),
-        
+                Helper.getEnums(tree)
-        Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:34 Redeclaration of variable with name \"x\".", e.getMessage());
     }
+
+    @Test
+    void shouldThrowExceptionIfVariableReferencesEnumButIsNotInitialized() {
+        // given
+        var tree = Helper.prepareParser("enum bar { A, B } function foo(): int { let x: bar; return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(
+                Helper.getFuncs(tree),
+                Helper.getStructs(tree),
+                Helper.getEnums(tree)
+        );
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:40 Variable x references an enum but is not initialized.", e.getMessage());
+    }
 }

src/test/java/VariableTest.java

@@ -13,7 +13,8 @@ public class VariableTest {
         ParseTree tree = Helper.prepareParser("function foo(): int { return x; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:29 Variable with name \"x\" not defined.", e.getMessage());
@@ -24,7 +25,8 @@ public class VariableTest {
         ParseTree tree = Helper.prepareParser("function foo(): int { let x: int; return x; } foo();");
         var funcs = Helper.getFuncs(tree);
         var structs = Helper.getStructs(tree);
-        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs);
+        var enums = Helper.getEnums(tree);
+        ContextAnalysis ctxAnal = new ContextAnalysis(funcs, structs, enums);
         
         Exception e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
         assertEquals("Error in line 1:41 Variable with name \"x\" has not been initialized.", e.getMessage());