Implemented CodeGen for Constants and fixed an issue regarding the placements of local variables on the JVM stack.

( index JVM = index localVars + 1)

src/main/java/Compiler.java

@@ -28,7 +28,7 @@ public class Compiler {
 
     public static void main(String[] args) throws Exception{
 
-        Path filePath = Paths.get("src/main/java/Input.java");
+        Path filePath = Paths.get("src/main/java/InputTest.java");
 
 
         // todo remove this debug info

src/main/java/abstractSyntaxTree/Expression/BooleanConstantExpression.java

@@ -5,6 +5,7 @@ import TypeCheck.TypeCheckException;
 import TypeCheck.TypeCheckResult;
 import abstractSyntaxTree.Parameter.ParameterList;
 import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
 
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -26,7 +27,11 @@ public class BooleanConstantExpression extends AbstractType implements IExpressi
 
     @Override
     public void codeGen(MethodVisitor mv, LinkedHashMap<String, String> localVars, HashMap<String, HashMap<String, String>> typeContext) throws Exception {
-
+        if (value){
+            mv.visitInsn(Opcodes.ICONST_1);
+        } else {
+            mv.visitInsn(Opcodes.ICONST_0);
+        }
     }
     @Override
     public TypeCheckResult getTypeCheckResult() {

src/main/java/abstractSyntaxTree/Expression/CharConstantExpression.java

@@ -4,6 +4,7 @@ import TypeCheck.AbstractType;
 import TypeCheck.TypeCheckResult;
 import abstractSyntaxTree.Parameter.ParameterList;
 import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
 
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -25,7 +26,7 @@ public class CharConstantExpression extends AbstractType implements IExpression{
 
     @Override
     public void codeGen(MethodVisitor mv, LinkedHashMap<String, String> localVars, HashMap<String, HashMap<String, String>> typeContext) throws Exception {
-
+        mv.visitIntInsn(Opcodes.BIPUSH, (int) value);
     }
 
     @Override

src/main/java/abstractSyntaxTree/Expression/IntConstantExpression.java

@@ -4,6 +4,7 @@ import TypeCheck.AbstractType;
 import TypeCheck.TypeCheckResult;
 import abstractSyntaxTree.Parameter.ParameterList;
 import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
 
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -27,7 +28,8 @@ public class IntConstantExpression extends AbstractType implements IExpression{
 
     @Override
     public void codeGen(MethodVisitor mv, LinkedHashMap<String, String> localVars, HashMap<String, HashMap<String, String>> typeContext) throws Exception {
-
+        //TODO: When we are finished this can be done more efficiently
+        mv.visitLdcInsn(value);
     }
 
     @Override

src/main/java/abstractSyntaxTree/Expression/LocalVarIdentifier.java

@@ -45,12 +45,12 @@ public class LocalVarIdentifier extends AbstractType implements IExpression{
             throw new Exception("Variable " + identifier + " not declared");
         }
 
-        // Load the variable onto the stack
+        // Find the index of the variable
         int index = -1;
         int counter = 0;
         for (String key : localVars.keySet()){
             if (key.equals(identifier)){
-                index = counter;
+                index = counter+1; // +1 because the first local variable is at index 1, 0 is used for "this"
                 break;
             }
             counter++;

src/main/java/abstractSyntaxTree/Statement/ReturnStatement.java

@@ -50,7 +50,6 @@ public class ReturnStatement extends AbstractType implements IStatement{
                 mv.visitInsn(Opcodes.IRETURN);
             } else {
                 mv.visitInsn(Opcodes.ARETURN);
-
             }
         } else {
             mv.visitInsn(Opcodes.RETURN);