diff --git a/docs/PA2.pdf b/docs/PA2.pdf
new file mode 100644
index 0000000..895503d
Binary files /dev/null and b/docs/PA2.pdf differ
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/AST.java b/miniJava/src/miniJava/AbstractSyntaxTrees/AST.java
new file mode 100644
index 0000000..f7f5194
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/AST.java
@@ -0,0 +1,27 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public abstract class AST {
+
+  public AST (SourcePosition posn) {
+    this.posn = posn;
+  }
+  
+  public String toString() {
+      String fullClassName = this.getClass().getName();
+      String cn = fullClassName.substring(1 + fullClassName.lastIndexOf('.'));
+      if (ASTDisplay.showPosition)
+    	  cn = cn + " " + posn.toString();
+      return cn;
+  }
+
+  public abstract <A,R> R visit(Visitor<A,R> v, A o);
+
+  public SourcePosition posn;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ASTDisplay.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ASTDisplay.java
new file mode 100644
index 0000000..be328a3
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ASTDisplay.java
@@ -0,0 +1,353 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+/*
+ * Display AST in text form
+ *   In-order traversal of AST, visiting each node with a method of the form  
+ *   
+ *       public Object visitXXX( XXX astnode, String arg)
+ *       
+ *   where arg is a prefix string (indentation) to precede display of ast node
+ *   and a null Object is returned as the result.
+ *   
+ *   implements Visitor<argtype,resulttype>
+ */
+public class ASTDisplay implements Visitor<String,Object> {
+	
+	public static boolean showPosition = false;
+    
+    /**
+     * print text representation of AST to stdout
+     * @param ast root node of AST 
+     */
+    public void showTree(AST ast){
+        System.out.println("======= AST Display =========================");
+        ast.visit(this, "");
+        System.out.println("=============================================");
+    }   
+    
+    // methods to format output
+    
+    /**
+     * display arbitrary text for a node
+     * @param prefix  spacing to indicate depth in AST
+     * @param text    preformatted node display
+     */
+    private void show(String prefix, String text) {
+        System.out.println(prefix + text);
+    }
+    
+    /**
+     * display AST node by name
+     * @param prefix  spacing to indicate depth in AST
+     * @param node    AST node, will be shown by name
+     */
+    private void show(String prefix, AST node) {
+    	System.out.println(prefix + node.toString());
+    }
+    
+    /**
+     * quote a string
+     * @param text    string to quote
+     */
+    private String quote(String text) {
+    	return ("\"" + text + "\"");
+    }
+    
+    /**
+     * increase depth in AST
+     * @param prefix  current spacing to indicate depth in AST
+     * @return  new spacing 
+     */
+    private String indent(String prefix) {
+        return prefix + "  ";
+    }
+    
+    
+	///////////////////////////////////////////////////////////////////////////////
+	//
+	// PACKAGE
+	//
+	/////////////////////////////////////////////////////////////////////////////// 
+
+    public Object visitPackage(Package prog, String arg){
+        show(arg, prog);
+        ClassDeclList cl = prog.classDeclList;
+        show(arg,"  ClassDeclList [" + cl.size() + "]");
+        String pfx = arg + "  . "; 
+        for (ClassDecl c: prog.classDeclList){
+            c.visit(this, pfx);
+        }
+        return null;
+    }
+    
+    
+	///////////////////////////////////////////////////////////////////////////////
+	//
+	// DECLARATIONS
+	//
+	///////////////////////////////////////////////////////////////////////////////
+    
+    public Object visitClassDecl(ClassDecl clas, String arg){
+        show(arg, clas);
+        show(indent(arg), quote(clas.name) + " classname");
+        show(arg,"  FieldDeclList [" + clas.fieldDeclList.size() + "]");
+        String pfx = arg + "  . "; 
+        for (FieldDecl f: clas.fieldDeclList)
+        	f.visit(this, pfx);
+        show(arg,"  MethodDeclList [" + clas.methodDeclList.size() + "]");
+        for (MethodDecl m: clas.methodDeclList)
+        	m.visit(this, pfx);
+        return null;
+    }
+    
+    public Object visitFieldDecl(FieldDecl f, String arg){
+       	show(arg, "(" + (f.isPrivate ? "private": "public") 
+    			+ (f.isStatic ? " static) " :") ") + f.toString());
+    	f.type.visit(this, indent(arg));
+    	show(indent(arg), quote(f.name) + " fieldname");
+        return null;
+    }
+    
+    public Object visitMethodDecl(MethodDecl m, String arg){
+       	show(arg, "(" + (m.isPrivate ? "private": "public") 
+    			+ (m.isStatic ? " static) " :") ") + m.toString());
+    	m.type.visit(this, indent(arg));
+    	show(indent(arg), quote(m.name) + " methodname");
+        ParameterDeclList pdl = m.parameterDeclList;
+        show(arg, "  ParameterDeclList [" + pdl.size() + "]");
+        String pfx = ((String) arg) + "  . ";
+        for (ParameterDecl pd: pdl) {
+            pd.visit(this, pfx);
+        }
+        StatementList sl = m.statementList;
+        show(arg, "  StmtList [" + sl.size() + "]");
+        for (Statement s: sl) {
+            s.visit(this, pfx);
+        }
+        if (m.returnExp != null) {
+            m.returnExp.visit(this, indent(arg));
+        }
+        return null;
+    }
+    
+    public Object visitParameterDecl(ParameterDecl pd, String arg){
+        show(arg, pd);
+        pd.type.visit(this, indent(arg));
+        show(indent(arg), quote(pd.name) + "parametername ");
+        return null;
+    } 
+    
+    public Object visitVarDecl(VarDecl vd, String arg){
+        show(arg, vd);
+        vd.type.visit(this, indent(arg));
+        show(indent(arg), quote(vd.name) + " varname");
+        return null;
+    }
+ 
+	
+	///////////////////////////////////////////////////////////////////////////////
+	//
+	// TYPES
+	//
+	///////////////////////////////////////////////////////////////////////////////
+    
+    public Object visitBaseType(BaseType type, String arg){
+        show(arg, type.typeKind + " " + type.toString());
+        return null;
+    }
+    
+    public Object visitClassType(ClassType type, String arg){
+        show(arg, type);
+        show(indent(arg), quote(type.className.spelling) + " classname");
+        return null;
+    }
+    
+    public Object visitArrayType(ArrayType type, String arg){
+        show(arg, type);
+        type.eltType.visit(this, indent(arg));
+        return null;
+    }
+    
+	
+	///////////////////////////////////////////////////////////////////////////////
+	//
+	// STATEMENTS
+	//
+	///////////////////////////////////////////////////////////////////////////////
+
+    public Object visitBlockStmt(BlockStmt stmt, String arg){
+        show(arg, stmt);
+        StatementList sl = stmt.sl;
+        show(arg,"  StatementList [" + sl.size() + "]");
+        String pfx = arg + "  . ";
+        for (Statement s: sl) {
+        	s.visit(this, pfx);
+        }
+        return null;
+    }
+    
+    public Object visitVardeclStmt(VarDeclStmt stmt, String arg){
+        show(arg, stmt);
+        stmt.varDecl.visit(this, indent(arg));	
+        stmt.initExp.visit(this, indent(arg));
+        return null;
+    }
+    
+    public Object visitAssignStmt(AssignStmt stmt, String arg){
+        show(arg,stmt);
+        stmt.ref.visit(this, indent(arg));
+        stmt.val.visit(this, indent(arg));
+        return null;
+    }
+    
+    public Object visitCallStmt(CallStmt stmt, String arg){
+        show(arg,stmt);
+        stmt.methodRef.visit(this, indent(arg));
+        ExprList al = stmt.argList;
+        show(arg,"  ExprList [" + al.size() + "]");
+        String pfx = arg + "  . ";
+        for (Expression e: al) {
+            e.visit(this, pfx);
+        }
+        return null;
+    }
+    
+    public Object visitIfStmt(IfStmt stmt, String arg){
+        show(arg,stmt);
+        stmt.cond.visit(this, indent(arg));
+        stmt.thenStmt.visit(this, indent(arg));
+        if (stmt.elseStmt != null)
+            stmt.elseStmt.visit(this, indent(arg));
+        return null;
+    }
+    
+    public Object visitWhileStmt(WhileStmt stmt, String arg){
+        show(arg, stmt);
+        stmt.cond.visit(this, indent(arg));
+        stmt.body.visit(this, indent(arg));
+        return null;
+    }
+    
+
+	///////////////////////////////////////////////////////////////////////////////
+	//
+	// EXPRESSIONS
+	//
+	///////////////////////////////////////////////////////////////////////////////
+
+    public Object visitUnaryExpr(UnaryExpr expr, String arg){
+        show(arg, expr);
+        expr.operator.visit(this, indent(arg));
+        expr.expr.visit(this, indent(indent(arg)));
+        return null;
+    }
+    
+    public Object visitBinaryExpr(BinaryExpr expr, String arg){
+        show(arg, expr);
+        expr.operator.visit(this, indent(arg));
+        expr.left.visit(this, indent(indent(arg)));
+        expr.right.visit(this, indent(indent(arg)));
+        return null;
+    }
+    
+    public Object visitRefExpr(RefExpr expr, String arg){
+        show(arg, expr);
+        expr.ref.visit(this, indent(arg));
+        return null;
+    }
+    
+    public Object visitCallExpr(CallExpr expr, String arg){
+        show(arg, expr);
+        expr.functionRef.visit(this, indent(arg));
+        ExprList al = expr.argList;
+        show(arg,"  ExprList + [" + al.size() + "]");
+        String pfx = arg + "  . ";
+        for (Expression e: al) {
+            e.visit(this, pfx);
+        }
+        return null;
+    }
+    
+    public Object visitLiteralExpr(LiteralExpr expr, String arg){
+        show(arg, expr);
+        expr.literal.visit(this, indent(arg));
+        return null;
+    }
+ 
+    public Object visitNewArrayExpr(NewArrayExpr expr, String arg){
+        show(arg, expr);
+        expr.eltType.visit(this, indent(arg));
+        expr.sizeExpr.visit(this, indent(arg));
+        return null;
+    }
+    
+    public Object visitNewObjectExpr(NewObjectExpr expr, String arg){
+        show(arg, expr);
+        expr.classtype.visit(this, indent(arg));
+        return null;
+    }
+    
+
+	///////////////////////////////////////////////////////////////////////////////
+	//
+	// REFERENCES
+	//
+	///////////////////////////////////////////////////////////////////////////////
+	
+    public Object visitQualifiedRef(QualifiedRef qr, String arg) {
+    	show(arg, qr);
+    	qr.id.visit(this, indent(arg));
+    	qr.ref.visit(this, indent(arg));
+	    return null;
+    }
+    
+    public Object visitIndexedRef(IndexedRef ir, String arg) {
+    	show(arg, ir);
+    	ir.indexExpr.visit(this, indent(arg));
+    	ir.ref.visit(this, indent(arg));
+    	return null;
+    }
+    
+    public Object visitIdRef(IdRef ref, String arg) {
+    	show(arg,ref);
+    	ref.id.visit(this, indent(arg));
+    	return null;
+    }
+   
+    public Object visitThisRef(ThisRef ref, String arg) {
+    	show(arg,ref);
+    	return null;
+    }
+    
+    
+	///////////////////////////////////////////////////////////////////////////////
+	//
+	// TERMINALS
+	//
+	///////////////////////////////////////////////////////////////////////////////
+    
+    public Object visitIdentifier(Identifier id, String arg){
+        show(arg, quote(id.spelling) + " " + id.toString());
+        return null;
+    }
+    
+    public Object visitOperator(Operator op, String arg){
+        show(arg, quote(op.spelling) + " " + op.toString());
+        return null;
+    }
+    
+    public Object visitIntLiteral(IntLiteral num, String arg){
+        show(arg, quote(num.spelling) + " " + num.toString());
+        return null;
+    }
+    
+    public Object visitBooleanLiteral(BooleanLiteral bool, String arg){
+        show(arg, quote(bool.spelling) + " " + bool.toString());
+        return null;
+    }
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ArrayType.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ArrayType.java
new file mode 100644
index 0000000..d8a5358
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ArrayType.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class ArrayType extends Type {
+
+	    public ArrayType(Type eltType, SourcePosition posn){
+	        super(TypeKind.ARRAY, posn);
+	        this.eltType = eltType;
+	    }
+	        
+	    public <A,R> R visit(Visitor<A,R> v, A o) {
+	        return v.visitArrayType(this, o);
+	    }
+
+	    public Type eltType;
+	}
+
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/AssignStmt.java b/miniJava/src/miniJava/AbstractSyntaxTrees/AssignStmt.java
new file mode 100644
index 0000000..1a6db99
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/AssignStmt.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class AssignStmt extends Statement
+{
+    public AssignStmt(Reference r, Expression e, SourcePosition posn){
+        super(posn);
+        ref = r;
+        val = e;
+    }
+    
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitAssignStmt(this, o);
+    }
+    
+    public Reference ref;
+    public Expression val;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/BaseType.java b/miniJava/src/miniJava/AbstractSyntaxTrees/BaseType.java
new file mode 100644
index 0000000..38ad09f
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/BaseType.java
@@ -0,0 +1,19 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class BaseType extends Type
+{
+    public BaseType(TypeKind t, SourcePosition posn){
+        super(t, posn);
+    }
+    
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitBaseType(this, o);
+    }
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/BinaryExpr.java b/miniJava/src/miniJava/AbstractSyntaxTrees/BinaryExpr.java
new file mode 100644
index 0000000..91fcc28
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/BinaryExpr.java
@@ -0,0 +1,26 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class BinaryExpr extends Expression
+{
+    public BinaryExpr(Operator o, Expression e1, Expression e2, SourcePosition posn){
+        super(posn);
+        operator = o;
+        left = e1;
+        right = e2;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitBinaryExpr(this, o);
+    }
+    
+    public Operator operator;
+    public Expression left;
+    public Expression right;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/BlockStmt.java b/miniJava/src/miniJava/AbstractSyntaxTrees/BlockStmt.java
new file mode 100644
index 0000000..933909c
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/BlockStmt.java
@@ -0,0 +1,22 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class BlockStmt extends Statement
+{
+    public BlockStmt(StatementList sl, SourcePosition posn){
+        super(posn);
+        this.sl = sl;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitBlockStmt(this, o);
+    }
+   
+    public StatementList sl;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/BooleanLiteral.java b/miniJava/src/miniJava/AbstractSyntaxTrees/BooleanLiteral.java
new file mode 100644
index 0000000..47b5f3f
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/BooleanLiteral.java
@@ -0,0 +1,19 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class BooleanLiteral extends Literal {
+
+  public BooleanLiteral(String spelling, SourcePosition posn) {
+    super (spelling,posn);
+  }
+ 
+  public <A,R> R visit(Visitor<A,R> v, A o) {
+      return v.visitBooleanLiteral(this, o);
+  }
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/CallExpr.java b/miniJava/src/miniJava/AbstractSyntaxTrees/CallExpr.java
new file mode 100644
index 0000000..1e17bbb
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/CallExpr.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class CallExpr extends Expression
+{
+    public CallExpr(Reference f, ExprList el, SourcePosition posn){
+        super(posn);
+        functionRef = f;
+        argList = el;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitCallExpr(this, o);
+    }
+    
+    public Reference functionRef;
+    public ExprList argList;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/CallStmt.java b/miniJava/src/miniJava/AbstractSyntaxTrees/CallStmt.java
new file mode 100644
index 0000000..a8aa63e
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/CallStmt.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class CallStmt extends Statement
+{
+    public CallStmt(Reference m, ExprList el, SourcePosition posn){
+        super(posn);
+        methodRef = m;
+        argList = el;
+    }
+    
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitCallStmt(this, o);
+    }
+    
+    public Reference methodRef;
+    public ExprList argList;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ClassDecl.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ClassDecl.java
new file mode 100644
index 0000000..bd776a8
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ClassDecl.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import  miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class ClassDecl extends Declaration {
+
+  public ClassDecl(String cn, FieldDeclList fdl, MethodDeclList mdl, SourcePosition posn) {
+	  super(cn, null, posn);
+	  fieldDeclList = fdl;
+	  methodDeclList = mdl;
+  }
+  
+  public <A,R> R visit(Visitor<A, R> v, A o) {
+      return v.visitClassDecl(this, o);
+  }
+      
+  public FieldDeclList fieldDeclList;
+  public MethodDeclList methodDeclList;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ClassDeclList.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ClassDeclList.java
new file mode 100644
index 0000000..489de35
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ClassDeclList.java
@@ -0,0 +1,34 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import java.util.*;
+
+public class ClassDeclList implements Iterable<ClassDecl>
+{
+	public ClassDeclList() {
+		classDeclList = new ArrayList<ClassDecl>();
+	}   
+
+	public void add(ClassDecl cd){
+		classDeclList.add(cd);
+	}
+
+	public ClassDecl get(int i){
+		return classDeclList.get(i);
+	}
+
+	public int size() {
+		return classDeclList.size();
+	}
+
+	public Iterator<ClassDecl> iterator() {
+		return classDeclList.iterator();
+	}
+
+	private List<ClassDecl> classDeclList;
+}
+
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ClassType.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ClassType.java
new file mode 100644
index 0000000..980d07f
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ClassType.java
@@ -0,0 +1,22 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class ClassType extends Type
+{
+    public ClassType(Identifier cn, SourcePosition posn){
+        super(TypeKind.CLASS, posn);
+        className = cn;
+    }
+            
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitClassType(this, o);
+    }
+
+    public Identifier className;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Declaration.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Declaration.java
new file mode 100644
index 0000000..2be0aae
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Declaration.java
@@ -0,0 +1,20 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Declaration extends AST {
+	
+	public Declaration(String name, Type type, SourcePosition posn) {
+		super(posn);
+		this.name = name;
+		this.type = type;
+	}
+	
+	public String name;
+	public Type type;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Declarators.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Declarators.java
new file mode 100644
index 0000000..b42e736
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Declarators.java
@@ -0,0 +1,14 @@
+package miniJava.AbstractSyntaxTrees;
+
+public class Declarators {
+	
+	public Declarators(boolean isPrivate, boolean isStatic, Type mt) {
+		this.isPrivate = isPrivate;
+		this.isStatic = isStatic;
+		this.mt = mt;
+	}
+	
+	public boolean isPrivate;
+    public boolean isStatic;
+    public Type mt;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ExprList.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ExprList.java
new file mode 100644
index 0000000..1a55c0d
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ExprList.java
@@ -0,0 +1,33 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import java.util.*;
+
+public class ExprList implements Iterable<Expression>
+{
+    public ExprList() {
+        elist = new ArrayList<Expression>();
+    }
+    
+    public void add(Expression e){
+        elist.add(e);
+    }
+    
+    public Expression get(int i){
+        return elist.get(i);
+    }
+    
+    public int size() {
+        return elist.size();
+    }
+    
+    public Iterator<Expression> iterator() {
+    	return elist.iterator();
+    }
+    
+    private List<Expression> elist;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Expression.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Expression.java
new file mode 100644
index 0000000..2c33a62
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Expression.java
@@ -0,0 +1,16 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import  miniJava.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Expression extends AST {
+
+  public Expression(SourcePosition posn) {
+    super (posn);
+  }
+  
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/FieldDecl.java b/miniJava/src/miniJava/AbstractSyntaxTrees/FieldDecl.java
new file mode 100644
index 0000000..5802447
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/FieldDecl.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class FieldDecl extends MemberDecl {
+	
+	public FieldDecl(boolean isPrivate, boolean isStatic, Type t, String name, SourcePosition posn){
+    super(isPrivate, isStatic, t, name, posn);
+	}
+	
+	public FieldDecl(MemberDecl md, SourcePosition posn) {
+		super(md,posn);
+	}
+	
+	public <A, R> R visit(Visitor<A, R> v, A o) {
+        return v.visitFieldDecl(this, o);
+    }
+}
+
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/FieldDeclList.java b/miniJava/src/miniJava/AbstractSyntaxTrees/FieldDeclList.java
new file mode 100644
index 0000000..2f6d96c
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/FieldDeclList.java
@@ -0,0 +1,34 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import java.util.*;
+
+public class FieldDeclList implements Iterable<FieldDecl>
+{
+	public FieldDeclList() {
+		fieldDeclList = new ArrayList<FieldDecl>();
+	}   
+
+	public void add(FieldDecl cd){
+		fieldDeclList.add(cd);
+	}
+
+	public FieldDecl get(int i){
+		return fieldDeclList.get(i);
+	}
+
+	public int size() {
+		return fieldDeclList.size();
+	}
+
+	public Iterator<FieldDecl> iterator() {
+		return fieldDeclList.iterator();
+	}
+
+	private List<FieldDecl> fieldDeclList;
+}
+
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/IdRef.java b/miniJava/src/miniJava/AbstractSyntaxTrees/IdRef.java
new file mode 100644
index 0000000..bf62d7d
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/IdRef.java
@@ -0,0 +1,22 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class IdRef extends Reference {
+	
+	public IdRef(Identifier id, SourcePosition posn){
+		super(posn);
+		this.id = id;
+	}
+		
+	public <A,R> R visit(Visitor<A,R> v, A o) {
+		return v.visitIdRef(this, o);
+	}
+
+	public Identifier id;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Identifier.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Identifier.java
new file mode 100644
index 0000000..ebffefa
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Identifier.java
@@ -0,0 +1,20 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class Identifier extends Terminal {
+
+  public Identifier (String s, SourcePosition posn) {
+    super (s,posn);
+  }
+
+  public <A,R> R visit(Visitor<A,R> v, A o) {
+      return v.visitIdentifier(this, o);
+  }
+
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/IfStmt.java b/miniJava/src/miniJava/AbstractSyntaxTrees/IfStmt.java
new file mode 100644
index 0000000..b22c31f
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/IfStmt.java
@@ -0,0 +1,33 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class IfStmt extends Statement
+{
+    public IfStmt(Expression b, Statement t, Statement e, SourcePosition posn){
+        super(posn);
+        cond = b;
+        thenStmt = t;
+        elseStmt = e;
+    }
+    
+    public IfStmt(Expression b, Statement t, SourcePosition posn){
+        super(posn);
+        cond = b;
+        thenStmt = t;
+        elseStmt = null;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitIfStmt(this, o);
+    }
+    
+    public Expression cond;
+    public Statement thenStmt;
+    public Statement elseStmt;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/IndexedRef.java b/miniJava/src/miniJava/AbstractSyntaxTrees/IndexedRef.java
new file mode 100644
index 0000000..c226b3f
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/IndexedRef.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class IndexedRef extends Reference {
+	
+	public IndexedRef(Reference ref, Expression expr, SourcePosition posn){
+		super(posn);
+		this.ref = ref;
+		this.indexExpr = expr;
+	}
+
+	public <A,R> R visit(Visitor<A,R> v, A o){
+		return v.visitIndexedRef(this, o);
+	}
+	
+	public Reference ref;
+	public Expression indexExpr;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/IntLiteral.java b/miniJava/src/miniJava/AbstractSyntaxTrees/IntLiteral.java
new file mode 100644
index 0000000..7926b9a
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/IntLiteral.java
@@ -0,0 +1,19 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class IntLiteral extends Literal {
+
+  public IntLiteral(String s, SourcePosition posn) {
+    super(s, posn);
+  }
+ 
+  public <A,R> R visit(Visitor<A,R> v, A o) {
+      return v.visitIntLiteral(this, o);
+  }
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Literal.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Literal.java
new file mode 100644
index 0000000..5c0f5cc
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Literal.java
@@ -0,0 +1,15 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Literal extends Terminal {
+
+	public Literal(String spelling, SourcePosition posn) {
+		super(spelling, posn);
+	}
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/LiteralExpr.java b/miniJava/src/miniJava/AbstractSyntaxTrees/LiteralExpr.java
new file mode 100644
index 0000000..49ab09f
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/LiteralExpr.java
@@ -0,0 +1,22 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class LiteralExpr extends Expression
+{
+    public LiteralExpr(Literal c, SourcePosition posn){
+        super(posn);
+        literal = c;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o){
+        return v.visitLiteralExpr(this, o);
+    }
+
+    public Literal literal;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/LocalDecl.java b/miniJava/src/miniJava/AbstractSyntaxTrees/LocalDecl.java
new file mode 100644
index 0000000..ce86df1
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/LocalDecl.java
@@ -0,0 +1,16 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public abstract class LocalDecl extends Declaration {
+	
+	public LocalDecl(String name, Type t, SourcePosition posn){
+		super(name,t,posn);
+	}
+
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/MemberDecl.java b/miniJava/src/miniJava/AbstractSyntaxTrees/MemberDecl.java
new file mode 100644
index 0000000..6db1e30
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/MemberDecl.java
@@ -0,0 +1,26 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+abstract public class MemberDecl extends Declaration {
+
+    public MemberDecl(boolean isPrivate, boolean isStatic, Type mt, String name, SourcePosition posn) {
+        super(name, mt, posn);
+        this.isPrivate = isPrivate;
+        this.isStatic = isStatic;
+    }
+    
+    public MemberDecl(MemberDecl md, SourcePosition posn){
+    	super(md.name, md.type, posn);
+    	this.isPrivate = md.isPrivate;
+    	this.isStatic = md.isStatic;
+    }
+    
+    public boolean isPrivate;
+    public boolean isStatic;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/MethodDecl.java b/miniJava/src/miniJava/AbstractSyntaxTrees/MethodDecl.java
new file mode 100644
index 0000000..276dfd1
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/MethodDecl.java
@@ -0,0 +1,26 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class MethodDecl extends MemberDecl {
+	
+	public MethodDecl(MemberDecl md, ParameterDeclList pl, StatementList sl, Expression e, SourcePosition posn){
+    super(md,posn);
+    parameterDeclList = pl;
+    statementList = sl;
+    returnExp = e;
+	}
+	
+	public <A, R> R visit(Visitor<A, R> v, A o) {
+        return v.visitMethodDecl(this, o);
+    }
+	
+	public ParameterDeclList parameterDeclList;
+	public StatementList statementList;
+	public Expression returnExp;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/MethodDeclList.java b/miniJava/src/miniJava/AbstractSyntaxTrees/MethodDeclList.java
new file mode 100644
index 0000000..f9b98a9
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/MethodDeclList.java
@@ -0,0 +1,34 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import java.util.*;
+
+public class MethodDeclList implements Iterable<MethodDecl>
+{
+	public MethodDeclList() {
+		methodDeclList = new ArrayList<MethodDecl>();
+	}   
+
+	public void add(MethodDecl cd){
+		methodDeclList.add(cd);
+	}
+
+	public MethodDecl get(int i){
+		return methodDeclList.get(i);
+	}
+
+	public int size() {
+		return methodDeclList.size();
+	}
+
+	public Iterator<MethodDecl> iterator() {
+		return methodDeclList.iterator();
+	}
+
+	private List<MethodDecl> methodDeclList;
+}
+
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/NewArrayExpr.java b/miniJava/src/miniJava/AbstractSyntaxTrees/NewArrayExpr.java
new file mode 100644
index 0000000..4d16a72
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/NewArrayExpr.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class NewArrayExpr extends NewExpr
+{
+    public NewArrayExpr(Type et, Expression e, SourcePosition posn){
+        super(posn);
+        eltType = et;
+        sizeExpr = e;
+    }
+    
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitNewArrayExpr(this, o);
+    }
+
+    public Type eltType;
+    public Expression sizeExpr;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/NewExpr.java b/miniJava/src/miniJava/AbstractSyntaxTrees/NewExpr.java
new file mode 100644
index 0000000..6e7876a
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/NewExpr.java
@@ -0,0 +1,15 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public abstract class NewExpr extends Expression {
+	
+	public NewExpr(SourcePosition posn) {
+	    super (posn);
+	  }
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/NewObjectExpr.java b/miniJava/src/miniJava/AbstractSyntaxTrees/NewObjectExpr.java
new file mode 100644
index 0000000..1f8b134
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/NewObjectExpr.java
@@ -0,0 +1,22 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class NewObjectExpr extends NewExpr
+{
+    public NewObjectExpr(ClassType ct, SourcePosition posn){
+        super(posn);
+        classtype = ct;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitNewObjectExpr(this, o);
+    }
+    
+    public ClassType classtype;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Operator.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Operator.java
new file mode 100644
index 0000000..88e291d
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Operator.java
@@ -0,0 +1,22 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+import miniJava.SyntacticAnalyzer.Token;
+
+public class Operator extends Terminal {
+
+  public Operator (Token t, SourcePosition posn) {
+    super (t.spelling, posn);
+  }
+
+  public <A,R> R visit(Visitor<A,R> v, A o) {
+      return v.visitOperator(this, o);
+  }
+
+  public Token token;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Package.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Package.java
new file mode 100644
index 0000000..dc29d7d
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Package.java
@@ -0,0 +1,22 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class Package extends AST {
+
+  public Package(ClassDeclList cdl, SourcePosition posn) {
+    super(posn);
+    classDeclList = cdl;
+  }
+    
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitPackage(this, o);
+    }
+
+    public ClassDeclList classDeclList;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ParameterDecl.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ParameterDecl.java
new file mode 100644
index 0000000..1bbee69
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ParameterDecl.java
@@ -0,0 +1,20 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class ParameterDecl extends LocalDecl {
+	
+	public ParameterDecl(Type t, String name, SourcePosition posn){
+		super(name, t, posn);
+	}
+	
+	public <A, R> R visit(Visitor<A, R> v, A o) {
+        return v.visitParameterDecl(this, o);
+    }
+}
+
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ParameterDeclList.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ParameterDeclList.java
new file mode 100644
index 0000000..64ae1cc
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ParameterDeclList.java
@@ -0,0 +1,33 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import java.util.*;
+
+public class ParameterDeclList implements Iterable<ParameterDecl>
+{
+    public ParameterDeclList() {
+    	parameterDeclList = new ArrayList<ParameterDecl>();
+    }
+    
+    public void add(ParameterDecl s){
+    	parameterDeclList.add(s);
+    }
+    
+    public ParameterDecl get(int i){
+        return parameterDeclList.get(i);
+    }
+    
+    public int size() {
+        return parameterDeclList.size();
+    }
+    
+    public Iterator<ParameterDecl> iterator() {
+    	return parameterDeclList.iterator();
+    }
+    
+    private List<ParameterDecl> parameterDeclList;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/QualifiedRef.java b/miniJava/src/miniJava/AbstractSyntaxTrees/QualifiedRef.java
new file mode 100644
index 0000000..3659a45
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/QualifiedRef.java
@@ -0,0 +1,25 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class QualifiedRef extends Reference {
+	
+	public QualifiedRef(Reference ref, Identifier id, SourcePosition posn){
+		super(posn);
+		this.ref = ref;
+		this.id  = id;
+	}
+
+	@Override
+	public <A, R> R visit(Visitor<A, R> v, A o) {
+		return v.visitQualifiedRef(this, o);
+	}
+
+	public Reference ref;
+	public Identifier id;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/RefExpr.java b/miniJava/src/miniJava/AbstractSyntaxTrees/RefExpr.java
new file mode 100644
index 0000000..48917dc
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/RefExpr.java
@@ -0,0 +1,22 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class RefExpr extends Expression
+{
+    public RefExpr(Reference r, SourcePosition posn){
+        super(posn);
+        ref = r;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitRefExpr(this, o);
+    }
+
+    public Reference ref;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Reference.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Reference.java
new file mode 100644
index 0000000..7ba8450
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Reference.java
@@ -0,0 +1,16 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Reference extends AST
+{
+	public Reference(SourcePosition posn){
+		super(posn);
+	}
+
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Statement.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Statement.java
new file mode 100644
index 0000000..4fa1af9
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Statement.java
@@ -0,0 +1,16 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import  miniJava.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Statement extends AST {
+
+  public Statement(SourcePosition posn) {
+    super (posn);
+  }
+
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/StatementList.java b/miniJava/src/miniJava/AbstractSyntaxTrees/StatementList.java
new file mode 100644
index 0000000..2b21f76
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/StatementList.java
@@ -0,0 +1,33 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import java.util.*;
+
+public class StatementList implements Iterable<Statement>
+{
+    public StatementList() {
+        slist = new ArrayList<Statement>();
+    }
+    
+    public void add(Statement s){
+        slist.add(s);
+    }
+    
+    public Statement get(int i){
+        return slist.get(i);
+    }
+    
+    public int size() {
+        return slist.size();
+    }
+    
+    public Iterator<Statement> iterator() {
+    	return slist.iterator();
+    }
+    
+    private List<Statement> slist;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Terminal.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Terminal.java
new file mode 100644
index 0000000..5b3f7e6
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Terminal.java
@@ -0,0 +1,18 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+abstract public class Terminal extends AST {
+
+  public Terminal (String s, SourcePosition posn) {
+    super(posn);
+    spelling = s;
+  }
+
+  public String spelling;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/ThisRef.java b/miniJava/src/miniJava/AbstractSyntaxTrees/ThisRef.java
new file mode 100644
index 0000000..3beab4e
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/ThisRef.java
@@ -0,0 +1,21 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class ThisRef extends Reference {
+	
+	public ThisRef(SourcePosition posn) {
+		super(posn);
+	}
+
+	@Override
+	public <A, R> R visit(Visitor<A, R> v, A o) {
+		return v.visitThisRef(this, o);
+	}
+	
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Type.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Type.java
new file mode 100644
index 0000000..cbcaa10
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Type.java
@@ -0,0 +1,21 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+abstract public class Type extends AST {
+    
+    public Type(TypeKind typ, SourcePosition posn){
+        super(posn);
+        typeKind = typ;
+    }
+    
+    public TypeKind typeKind;
+    
+}
+
+        
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/TypeKind.java b/miniJava/src/miniJava/AbstractSyntaxTrees/TypeKind.java
new file mode 100644
index 0000000..b6bd818
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/TypeKind.java
@@ -0,0 +1,16 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+public enum TypeKind {
+        VOID,
+		INT,
+        BOOLEAN,
+        CLASS,
+        ARRAY,
+        UNSUPPORTED,
+        ERROR;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/UnaryExpr.java b/miniJava/src/miniJava/AbstractSyntaxTrees/UnaryExpr.java
new file mode 100644
index 0000000..6bff8ce
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/UnaryExpr.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class UnaryExpr extends Expression
+{
+    public UnaryExpr(Operator o, Expression e, SourcePosition posn){
+        super(posn);
+        operator = o;
+        expr = e;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitUnaryExpr(this, o);
+    }
+
+    public Operator operator;
+    public Expression expr;
+}
\ No newline at end of file
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/VarDecl.java b/miniJava/src/miniJava/AbstractSyntaxTrees/VarDecl.java
new file mode 100644
index 0000000..3fe19a8
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/VarDecl.java
@@ -0,0 +1,19 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class VarDecl extends LocalDecl {
+	
+	public VarDecl(Type t, String name, SourcePosition posn) {
+		super(name, t, posn);
+	}
+	
+	public <A,R> R visit(Visitor<A,R> v, A o) {
+		return v.visitVarDecl(this, o);
+	}
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/VarDeclStmt.java b/miniJava/src/miniJava/AbstractSyntaxTrees/VarDeclStmt.java
new file mode 100644
index 0000000..b960b2e
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/VarDeclStmt.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class VarDeclStmt extends Statement
+{
+    public VarDeclStmt(VarDecl vd, Expression e, SourcePosition posn){
+        super(posn);
+        varDecl = vd;
+        initExp = e;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitVardeclStmt(this, o);
+    }
+
+    public VarDecl varDecl;
+    public Expression initExp;
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/Visitor.java b/miniJava/src/miniJava/AbstractSyntaxTrees/Visitor.java
new file mode 100644
index 0000000..74506e0
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/Visitor.java
@@ -0,0 +1,57 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+/**
+ * An implementation of the Visitor interface provides a method visitX
+ * for each non-abstract AST class X.  
+ */
+public interface Visitor<ArgType,ResultType> {
+
+  // Package
+    public ResultType visitPackage(Package prog, ArgType arg);
+
+  // Declarations
+    public ResultType visitClassDecl(ClassDecl cd, ArgType arg);
+    public ResultType visitFieldDecl(FieldDecl fd, ArgType arg);
+    public ResultType visitMethodDecl(MethodDecl md, ArgType arg);
+    public ResultType visitParameterDecl(ParameterDecl pd, ArgType arg);
+    public ResultType visitVarDecl(VarDecl decl, ArgType arg);
+ 
+  // Types
+    public ResultType visitBaseType(BaseType type, ArgType arg);
+    public ResultType visitClassType(ClassType type, ArgType arg);
+    public ResultType visitArrayType(ArrayType type, ArgType arg);
+    
+  // Statements
+    public ResultType visitBlockStmt(BlockStmt stmt, ArgType arg);
+    public ResultType visitVardeclStmt(VarDeclStmt stmt, ArgType arg);
+    public ResultType visitAssignStmt(AssignStmt stmt, ArgType arg);
+    public ResultType visitCallStmt(CallStmt stmt, ArgType arg);
+    public ResultType visitIfStmt(IfStmt stmt, ArgType arg);
+    public ResultType visitWhileStmt(WhileStmt stmt, ArgType arg);
+    
+  // Expressions
+    public ResultType visitUnaryExpr(UnaryExpr expr, ArgType arg);
+    public ResultType visitBinaryExpr(BinaryExpr expr, ArgType arg);
+    public ResultType visitRefExpr(RefExpr expr, ArgType arg);
+    public ResultType visitCallExpr(CallExpr expr, ArgType arg);
+    public ResultType visitLiteralExpr(LiteralExpr expr, ArgType arg);
+    public ResultType visitNewObjectExpr(NewObjectExpr expr, ArgType arg);
+    public ResultType visitNewArrayExpr(NewArrayExpr expr, ArgType arg);
+    
+  // References
+    public ResultType visitQualifiedRef(QualifiedRef ref, ArgType arg);
+    public ResultType visitIndexedRef(IndexedRef ref, ArgType arg);
+    public ResultType visitIdRef(IdRef ref, ArgType arg);
+    public ResultType visitThisRef(ThisRef ref, ArgType arg);
+
+  // Terminals
+    public ResultType visitIdentifier(Identifier id, ArgType arg);
+    public ResultType visitOperator(Operator op, ArgType arg);
+    public ResultType visitIntLiteral(IntLiteral num, ArgType arg);
+    public ResultType visitBooleanLiteral(BooleanLiteral bool, ArgType arg);
+}
diff --git a/miniJava/src/miniJava/AbstractSyntaxTrees/WhileStmt.java b/miniJava/src/miniJava/AbstractSyntaxTrees/WhileStmt.java
new file mode 100644
index 0000000..d76ac87
--- /dev/null
+++ b/miniJava/src/miniJava/AbstractSyntaxTrees/WhileStmt.java
@@ -0,0 +1,24 @@
+/**
+ * miniJava Abstract Syntax Tree classes
+ * @author prins
+ * @version COMP 520 (v2.2)
+ */
+package miniJava.AbstractSyntaxTrees;
+
+import miniJava.SyntacticAnalyzer.SourcePosition;
+
+public class WhileStmt extends Statement
+{
+    public WhileStmt(Expression b, Statement s, SourcePosition posn){
+        super(posn);
+        cond = b;
+        body = s;
+    }
+        
+    public <A,R> R visit(Visitor<A,R> v, A o) {
+        return v.visitWhileStmt(this, o);
+    }
+
+    public Expression cond;
+    public Statement body;
+}
diff --git a/miniJava/src/miniJava/Compiler.java b/miniJava/src/miniJava/Compiler.java
index 40fe744..c850c20 100644
--- a/miniJava/src/miniJava/Compiler.java
+++ b/miniJava/src/miniJava/Compiler.java
@@ -1,7 +1,10 @@
 package miniJava;
 
 import java.io.*;
+
 import miniJava.SyntacticAnalyzer.*;
+import miniJava.AbstractSyntaxTrees.*;
+import miniJava.AbstractSyntaxTrees.Package;
 
 public class Compiler {
 	
@@ -16,18 +19,19 @@ public class Compiler {
 		
 		try(FileReader input = new FileReader(args[0])) {
 			
+			// Setup
 			Scanner scanner = new Scanner(new BufferedReader(input));
 			Parser parser = new Parser(scanner);
-			parser.parse();
+			Package p = parser.parse();
 			
-			System.out.println("Works");
+			// Display
+			ASTDisplay display = new ASTDisplay();
+			display.showTree(p);
 			System.exit(0);
 			
 		} catch(FileNotFoundException e) {
-			System.out.println("Not Found");
 			System.exit(rc);
 		} catch(IOException e) {
-			System.out.println("Not Works");
 			System.exit(rc);
 		}
 	}
diff --git a/miniJava/src/miniJava/SyntacticAnalyzer/Parser.java b/miniJava/src/miniJava/SyntacticAnalyzer/Parser.java
index 068cf4b..6930c9a 100644
--- a/miniJava/src/miniJava/SyntacticAnalyzer/Parser.java
+++ b/miniJava/src/miniJava/SyntacticAnalyzer/Parser.java
@@ -2,6 +2,8 @@ package miniJava.SyntacticAnalyzer;
 
 import java.io.*;
 import java.util.LinkedList;
+import miniJava.AbstractSyntaxTrees.*;
+import miniJava.AbstractSyntaxTrees.Package;
 
 public class Parser {
 	
@@ -13,191 +15,271 @@ public class Parser {
 		this.stream = new LinkedList<Token>();
 	}
 		
-	
 	/**
 	 * Program ::= (ClassDeclaration)* eot
+	 * @return
 	 * @throws IOException
 	 */
-	public void parse() throws IOException {
-		while(peek(1).type == Token.TYPE.CLASS) parseClassDeclaration();
+	public Package parse() throws IOException {
+		ClassDeclList decls = new ClassDeclList();
+		while(peek(1).type == Token.TYPE.CLASS) {
+			decls.add(parseClassDeclaration());
+		}
+		
 		accept(Token.TYPE.EOT);
+		return new Package(decls, null);
 	}
 			
-	
 	/**
 	 * ClassDeclaration ::=   
 	 *     class id  {       
 	 *	       (Declarators id (; | MethodDeclaration))*   
 	 *     }
+	 * @return
 	 * @throws IOException
 	 */
-	private void parseClassDeclaration() throws IOException {
+	private ClassDecl parseClassDeclaration() throws IOException {
 		
 		// Class Header
 		accept(Token.TYPE.CLASS);
-		accept(Token.TYPE.ID);
+		String cn = accept(Token.TYPE.ID).spelling;
 		accept(Token.TYPE.LBRACKET);
 		
+		// Setup
+		FieldDeclList fdl = new FieldDeclList();
+		MethodDeclList mdl = new MethodDeclList();
+		
 		// Class Body
 		while(peek(1).type != Token.TYPE.RBRACKET) {
-			parseDeclarators();
-			accept(Token.TYPE.ID);
-			if(peek(1).type == Token.TYPE.SEMICOLON) accept(Token.TYPE.SEMICOLON);
-			else parseMethodDeclaration();
+			Declarators d = parseDeclarators();
+			String name = accept(Token.TYPE.ID).spelling;
+			FieldDecl f = new FieldDecl(d.isPrivate, d.isStatic, d.mt, name, null);
+			
+			// Field Declarations
+			if(peek(1).type == Token.TYPE.SEMICOLON) {
+				accept(Token.TYPE.SEMICOLON);
+				fdl.add(f);
+			} 
+			
+			// Method Declarations
+			else mdl.add(parseMethodDeclaration(f));
 		}
 		
-		accept(Token.TYPE.RBRACKET);	
+		accept(Token.TYPE.RBRACKET);
+		return new ClassDecl(cn, fdl, mdl, null);
 	}
 	
+	/**
+	 * Declarators ::= (public | private)? static? Type
+	 * @return
+	 * @throws IOException
+	 */
+	private Declarators parseDeclarators() throws IOException {
+		
+		// Visibility
+		boolean isPrivate = false;
+		if(peek(1).type == Token.TYPE.PUBLIC) {
+			accept(Token.TYPE.PUBLIC);
+		} else if(peek(1).type == Token.TYPE.PRIVATE) {
+			isPrivate = true;
+			accept(Token.TYPE.PRIVATE); 
+		}
+		
+		// Class Methods
+		boolean isStatic = false;
+		if(peek(1).type == Token.TYPE.STATIC) {
+			isStatic = true;
+			accept(Token.TYPE.STATIC);
+		}
+		
+		Type t = parseType();
+		return new Declarators(isPrivate, isStatic, t);
+	}
 
 	/**
-	 * MethodDeclaration ::=
+	 * * MethodDeclaration ::=
 	 *     (ParameterList?) {
 	 *	       Statement* (return Expression ;)?
 	 *	   }
+	 * @param f describes the declaratory aspect of the method
+	 * @return
 	 * @throws IOException
 	 */
-	private void parseMethodDeclaration() throws IOException {
-
+	private MethodDecl parseMethodDeclaration(FieldDecl f) throws IOException {
+		
 		// Method Header
 		accept(Token.TYPE.LPAREN);
-		if(peek(1).type != Token.TYPE.RPAREN) parseParameterList();
+		
+		// Parameter List
+		ParameterDeclList pdl = new ParameterDeclList();
+		if(peek(1).type != Token.TYPE.RPAREN) pdl = parseParameterList();
+		
 		accept(Token.TYPE.RPAREN);
 		accept(Token.TYPE.LBRACKET);
 		
 		// Method Body
+		Expression re = null;
+		StatementList stl = new StatementList();
 		while(peek(1).type != Token.TYPE.RBRACKET) {
 			
 			if(peek(1).type == Token.TYPE.RETURN) {
 				accept(Token.TYPE.RETURN);
-				parseExpression();
+				re = parseExpression();
 				accept(Token.TYPE.SEMICOLON);
 				break;
 			}
 			
-			parseStatement();
+			stl.add(parseStatement());
 		}
 		
 		accept(Token.TYPE.RBRACKET);
+		return new MethodDecl(f, pdl, stl, re, null);
 	}
 	
-
-	/**
-	 * Declarators ::= (public | private)? static? Type
-	 * @throws IOException
-	 */
-	private void parseDeclarators() throws IOException {
-		
-		if(peek(1).type == Token.TYPE.PUBLIC) accept(Token.TYPE.PUBLIC);
-		else if(peek(1).type == Token.TYPE.PRIVATE) accept(Token.TYPE.PRIVATE); 
-		
-		if(peek(1).type == Token.TYPE.STATIC) accept(Token.TYPE.STATIC);
-		parseType();
-	}
-	
-
 	/**
 	 * Type ::= boolean | void | int ([])? | id ([])?
+	 * @return
 	 * @throws IOException
 	 */
-	private void parseType() throws IOException {
+	private Type parseType() throws IOException {
 		
-		Token.TYPE type = peek(1).type;
-		
-		switch(type) {
+		switch(peek(1).type) {
 		
 			case BOOLEAN:
-			case VOID:
-				accept(type);
-				break;
+				accept(Token.TYPE.BOOLEAN);
+				return new BaseType(TypeKind.BOOLEAN, null);
+				
+			case VOID:
+				accept(Token.TYPE.VOID);
+				return new BaseType(TypeKind.VOID, null);
+				
+			case INT: {
+				accept(Token.TYPE.INT);
+				BaseType b = new BaseType(TypeKind.INT, null);
 				
-			case INT:
-			case ID:
-				accept(type);
 				if(peek(1).type == Token.TYPE.LSQUARE) {
 					accept(Token.TYPE.LSQUARE);
 					accept(Token.TYPE.RSQUARE);
+					return new ArrayType(b, null);
 				}
-				break;
+				
+				return b;
+			}
+				
+			case ID: {
+				String cn = accept(peek(1).type).spelling;
+				Identifier i = new Identifier(cn, null);
+				ClassType c = new ClassType(i, null);
+				
+				if(peek(1).type == Token.TYPE.LSQUARE) {
+					accept(Token.TYPE.LSQUARE);
+					accept(Token.TYPE.RSQUARE);
+					return new ArrayType(c, null);
+				}
+				
+				return c;
+			}
 				
 			default:
 				throw new IOException();
 		}
 	}
 	
-
 	/**
 	 * ParameterList ::= Type id (, Type id)*
+	 * @return
 	 * @throws IOException
 	 */
-	private void parseParameterList() throws IOException {
-		parseType();
-		accept(Token.TYPE.ID);
+	private ParameterDeclList parseParameterList() throws IOException {
+		
+		ParameterDeclList decls = new ParameterDeclList(); 
+		
+		// First Parameter
+		Type t = parseType();
+		String name = accept(Token.TYPE.ID).spelling;
+		decls.add(new ParameterDecl(t, name, null));
+		
+		// Remainder of List
 		while(peek(1).type == Token.TYPE.COMMA) {
 			accept(Token.TYPE.COMMA);
-			parseType();
-			accept(Token.TYPE.ID);
+			t = parseType();
+			name = accept(Token.TYPE.ID).spelling;
+			decls.add(new ParameterDecl(t, name, null));
 		}
+		
+		return decls;
 	}
 	
-
 	/**
 	 * ArgumentList ::= Expression (, Expression)*
+	 * @return
 	 * @throws IOException
 	 */
-	private void parseArgumentList() throws IOException {
-		parseExpression();
+	private ExprList parseArgumentList() throws IOException {
+		ExprList e = new ExprList();
+		e.add(parseExpression());
 		while(peek(1).type == Token.TYPE.COMMA) {
 			accept(Token.TYPE.COMMA);
-			parseExpression();
+			e.add(parseExpression());
 		}
+		
+		return e;
 	}
 	
-
 	/**
 	 * Reference ::= BaseRef (. BaseRef)*
+	 * @return
 	 * @throws IOException
 	 */
-	private void parseReference() throws IOException {
-		parseBaseRef();
+	private Reference parseReference() throws IOException {
+		Reference r = parseBaseRef();
 		while(peek(1).type == Token.TYPE.PERIOD) {
 			accept(Token.TYPE.PERIOD);
-			accept(Token.TYPE.ID);
+			String name = accept(Token.TYPE.ID).spelling;
+			Identifier id = new Identifier(name, null);
+			r = new QualifiedRef(r, id, null);
+			
 			if(peek(1).type == Token.TYPE.LSQUARE) {
 				accept(Token.TYPE.LSQUARE);
-				parseExpression();
+				Expression e = parseExpression();
 				accept(Token.TYPE.RSQUARE);
+				r = new IndexedRef(r, e, null);
+			}
+		}		
+		
+		return r;
+	}
+
+	/**
+	 * BaseRef ::= this | id ([ Expression])?
+	 * @return
+	 * @throws IOException
+	 */
+	private Reference parseBaseRef() throws IOException {
+		
+		switch(peek(1).type) {
+			case THIS:
+				accept(Token.TYPE.THIS);
+				return new ThisRef(null);
+				
+			// id ([ Expression])?
+			default: {
+				String id = accept(Token.TYPE.ID).spelling;
+				Identifier i = new Identifier(id, null);
+				IdRef r = new IdRef(i, null);
+				
+				if(peek(1).type == Token.TYPE.LSQUARE) {
+					accept(Token.TYPE.LSQUARE);
+					Expression e = parseExpression();
+					accept(Token.TYPE.RSQUARE);
+					return new IndexedRef(r, e, null);
+				}
+				
+				return r;
 			}
 		}
 	}
 	
-	
-	/**
-	 * BaseRef ::= this | id ([ Expression])?
-	 * @throws IOException
-	 */
-	private void parseBaseRef() throws IOException {
-		
-		switch(peek(1).type) {
-		
-			// this
-			case THIS:
-				accept(Token.TYPE.THIS);
-				break;
-				
-			// id ([ Expression])?
-			default:
-				accept(Token.TYPE.ID);
-				if(peek(1).type == Token.TYPE.LSQUARE) {
-					accept(Token.TYPE.LSQUARE);
-					parseExpression();
-					accept(Token.TYPE.RSQUARE);
-				}
-				break;
-		}
-	}
-	
-
 	/**
 	 * Statement ::=
 	 *     {Statement*}
@@ -206,82 +288,100 @@ public class Parser {
 	 *	 | Reference ( ArgumentList? );
 	 *	 | if (Expression) Statement (else Statement)?
 	 *	 | while (Expression) Statement
+	 * @return
 	 * @throws IOException
 	 */
-	private void parseStatement() throws IOException {
+	private Statement parseStatement() throws IOException {
 		
 		switch(peek(1).type) {
 		
 			// { Statement* }
-			case LBRACKET:
+			case LBRACKET: {
 				accept(Token.TYPE.LBRACKET);
+				StatementList stl = new StatementList();
 				while(peek(1).type != Token.TYPE.RBRACKET) {
-					parseStatement();
+					stl.add(parseStatement());
 				}
 				accept(Token.TYPE.RBRACKET);
-				break;
+				
+				return new BlockStmt(stl, null);
+			}
 				
 			// if (Expression) Statement (else Statement)?
-			case IF:
+			case IF: {
 				accept(Token.TYPE.IF);
 				accept(Token.TYPE.LPAREN);
-				parseExpression();
+				Expression e = parseExpression();
 				accept(Token.TYPE.RPAREN);
-				parseStatement();
+				Statement s1 = parseStatement();
 				if(peek(1).type == Token.TYPE.ELSE) {
 					accept(Token.TYPE.ELSE);
-					parseStatement();
+					Statement s2 = parseStatement();
+					return new IfStmt(e, s1, s2, null);
 				}
-				break;
+				
+				return new IfStmt(e, s1, null);
+			}
 				
 			// while (Expression) Statement
-			case WHILE:
+			case WHILE: {
 				accept(Token.TYPE.WHILE);
 				accept(Token.TYPE.LPAREN);
-				parseExpression();
+				Expression e = parseExpression();
 				accept(Token.TYPE.RPAREN);
-				parseStatement();
-				break;
+				Statement s = parseStatement();
+				
+				return new WhileStmt(e, s, null);
+			}
 				
 			// Type id = Expression ;
-			case BOOLEAN:
-			case VOID:
-			case INT:
-			case ID:
+			case BOOLEAN: case VOID: case INT: case ID: {
 				
 				// Must be a type though there is a possibility of a reference
-				if(peek(1).type != Token.TYPE.ID
-				|| peek(2).type == Token.TYPE.ID
+				if(peek(1).type != Token.TYPE.ID || peek(2).type == Token.TYPE.ID
 				||(peek(2).type == Token.TYPE.LSQUARE && peek(3).type == Token.TYPE.RSQUARE)) {
-					parseType();
-					accept(Token.TYPE.ID);
+					Type t = parseType();
+					String name = accept(Token.TYPE.ID).spelling;
+					VarDecl v = new VarDecl(t, name, null);
+					
 					accept(Token.TYPE.EQUALS);
-					parseExpression();
+					Expression e = parseExpression();
 					accept(Token.TYPE.SEMICOLON);
-					break;
+					
+					return new VarDeclStmt(v, e, null);
 				}
 				
 				/* Fall Through */
+			}
+
+			default: {
+				Statement s = null;
+				Reference r = parseReference();
 				
-			// Reference = Expression ; | Reference ( ArgumentList? ) ; 
-			default:
-				parseReference();
-				
+				// Reference ( ArgumentList? ) ; 
 				if(peek(1).type == Token.TYPE.LPAREN) {
+					ExprList e = new ExprList();
 					accept(Token.TYPE.LPAREN);
-					if(peek(1).type != Token.TYPE.RPAREN) parseArgumentList();
+					if(peek(1).type != Token.TYPE.RPAREN) {
+						e = parseArgumentList();
+					}
 					accept(Token.TYPE.RPAREN);
-				} else {
+					s = new CallStmt(r, e, null);
+				} 
+				
+				// Reference = Expression ;
+				else {
 					accept(Token.TYPE.EQUALS);
-					parseExpression();
+					Expression e = parseExpression();
+					s = new AssignStmt(r, e, null);
 				}
 				
 				accept(Token.TYPE.SEMICOLON);
-				break;
-		}		
+				return s;
+			}
+		}
 	}
 	
-	
 	/**
 	 * Expression ::=
 	 *     Reference
@@ -291,92 +391,198 @@ public class Parser {
 	 *   | ( Expression )
 	 *   | num | true | false
 	 *   | new (id() | int [ Expression ] | id [ Expression ] )
+	 * @return
 	 * @throws IOException
 	 */
-	private void parseExpression() throws IOException {
+	private Expression parseExpression() throws IOException {
 		
+		Expression e = null;
 		switch(peek(1).type) {
 		
-			// num | true | false
-			case NUM:
-			case TRUE:
-			case FALSE:
-				accept(peek(1).type);
+			// num
+			case NUM: {
+				String number = accept(Token.TYPE.NUM).spelling;
+				IntLiteral i = new IntLiteral(number, null);
+				e = new LiteralExpr(i, null);
 				break;
+			}
+			
+			// true | false
+			case TRUE:
+			case FALSE: {
+				String bool = accept(peek(1).type).spelling;
+				BooleanLiteral b = new BooleanLiteral(bool, null);
+				e = new LiteralExpr(b, null);
+				break;
+			}
 				
 			// ( Expression )
-			case LPAREN:
+			case LPAREN: {
 				accept(Token.TYPE.LPAREN);
-				parseExpression();
+				e = parseExpression();
 				accept(Token.TYPE.RPAREN);
 				break;
+			}
 				
 			// unop Expression
 			case UNOP:
-				accept(Token.TYPE.UNOP);
-				parseExpression();
-				break;
-				
-			// Must be a minus sign
-			case BINOP:
-				if(peek(1).attr.equals("-")) {
-					accept(Token.TYPE.BINOP);
-					parseExpression();
-				}
+			case BINOP: {
+				if(peek(1).spelling.equals("!") || peek(1).spelling.equals("-")) {
+					Operator o = new Operator(accept(peek(1).type), null);
+					e = new UnaryExpr(o, parseExpression(), null);
+				} 
 				else throw new IOException();
 				break;
+			}
 				
 			// new ( int [ Expression ]  | id ( ) | id [ Expression ] )
-			case NEW:
+			case NEW: {
 				accept(Token.TYPE.NEW);
 				
 				if(peek(1).type == Token.TYPE.INT) {
 					accept(Token.TYPE.INT);
 					accept(Token.TYPE.LSQUARE);
-					parseExpression();
+					Expression e2 = parseExpression();
 					accept(Token.TYPE.RSQUARE);
+					
+					BaseType b = new BaseType(TypeKind.INT, null);
+					e = new NewArrayExpr(b, e2, null);
 				}
 				
 				else {
-					accept(Token.TYPE.ID);
+					String cn = accept(Token.TYPE.ID).spelling;
+					Identifier i = new Identifier(cn, null);
+					ClassType c = new ClassType(i, null);
 					
 					if(peek(1).type == Token.TYPE.LPAREN){
 						accept(Token.TYPE.LPAREN);
 						accept(Token.TYPE.RPAREN);
-					}
-					
-					else {
+						e = new NewObjectExpr(c, null);
+					} else {
 						accept(Token.TYPE.LSQUARE);
-						parseExpression();
+						Expression e2 = parseExpression();
 						accept(Token.TYPE.RSQUARE);
+						e = new NewArrayExpr(c, e2, null);
 					}
 				}
 				
 				break;
+			}
 				
-			// Reference | Reference (ArgumentList?)
-			case THIS:
-			case ID:
-				parseReference();
+			// Reference ((ArgumentList?))?
+			case THIS: case ID: {
+				Reference r = parseReference();
 				if(peek(1).type == Token.TYPE.LPAREN) {
 					accept(Token.TYPE.LPAREN);
-					if(peek(1).type != Token.TYPE.RPAREN) parseArgumentList();
+					ExprList el = new ExprList();
+					if(peek(1).type != Token.TYPE.RPAREN) {
+						el = parseArgumentList();
+					}
 					accept(Token.TYPE.RPAREN);
+					e = new CallExpr(r, el, null);
+				} else {
+					e = new RefExpr(r, null);
 				}
-				break;
 				
-			// Expression binop Expression
-			default:
-				accept(Token.TYPE.BINOP);
-				parseExpression();
 				break;
+			}
+				
+			default:
+				throw new IOException();
 		}
 		
 		// Expression binop Expression
 		if(peek(1).type == Token.TYPE.BINOP) {
-			accept(Token.TYPE.BINOP);
-			parseExpression();
+			Operator o = new Operator(accept(Token.TYPE.BINOP), null);
+			e = new BinaryExpr(o, e, parseDExpression(), null);
 		}
+		
+		return e;
+	}
+	
+	/**
+	 * Disjunction
+	 * @throws IOException
+	 */
+	private Expression parseDExpression() throws IOException {
+		Expression e = parseCExpression();
+		while(peek(1).spelling.equals("||")) {
+			Operator o = new Operator(accept(Token.TYPE.BINOP), null);
+			e = new BinaryExpr(o, e, parseCExpression(), null);
+		}
+		
+		return e;
+	}
+	
+	/**
+	 * Conjunction
+	 * @throws IOException
+	 */
+	private Expression parseCExpression() throws IOException {
+		Expression e = parseEExpression();
+		while(peek(1).spelling.equals("&&")) {
+			Operator o = new Operator(accept(Token.TYPE.BINOP), null);
+			e = new BinaryExpr(o, e, parseEExpression(), null);
+		}
+		
+		return e;
+	}
+	
+	/**
+	 * Equality
+	 * @throws IOException
+	 */
+	private Expression parseEExpression() throws IOException {
+		Expression e = parseRExpression();
+		while(peek(1).spelling.equals("==") || peek(1).spelling.equals("!=")) {
+			Operator o = new Operator(accept(Token.TYPE.BINOP), null);
+			e = new BinaryExpr(o, e, parseRExpression(), null);
+		}
+		
+		return e;
+	}
+	
+	/**
+	 * Relational
+	 * @throws IOException
+	 */
+	private Expression parseRExpression() throws IOException {
+		Expression e = parseAExpression();
+		while(peek(1).spelling.equals("<=") || peek(1).spelling.equals(">=")
+		   || peek(1).spelling.equals("<") || peek(1).spelling.equals(">")) {
+			Operator o = new Operator(accept(Token.TYPE.BINOP), null);
+			e = new BinaryExpr(o, e, parseAExpression(), null);
+		}
+		
+		return e;
+	}
+
+	/**
+	 * Additive
+	 * @throws IOException
+	 */
+	private Expression parseAExpression() throws IOException {
+		Expression e = parseMExpression();
+		while(peek(1).spelling.equals("+") || peek(1).spelling.equals("-")) {
+			Operator o = new Operator(accept(Token.TYPE.BINOP), null);
+			e = new BinaryExpr(o, e, parseMExpression(), null);
+		}
+		
+		return e;
+	}
+
+	/**
+	 * Multiplicative
+	 * @throws IOException
+	 */
+	private Expression parseMExpression() throws IOException {
+		Expression e = parseExpression();
+		while(peek(1).spelling.equals("*") || peek(1).spelling.equals("/")) {
+			Operator o = new Operator(accept(Token.TYPE.BINOP), null);
+			e = new BinaryExpr(o, e, parseExpression(), null);
+		}
+		
+		return e;
 	}
 	
 	
@@ -401,9 +607,11 @@ public class Parser {
 	 * Consumes token or throws exception.
 	 * @throws IOException
 	 */
-	private void accept(Token.TYPE type) throws IOException {
+	private Token accept(Token.TYPE type) throws IOException {
 		Token next = peek(1);
 		if(next.type == type) stream.poll();
 		else throw new IOException();
+		
+		return next;
 	}
 }
diff --git a/miniJava/src/miniJava/SyntacticAnalyzer/Scanner.java b/miniJava/src/miniJava/SyntacticAnalyzer/Scanner.java
index 49cb14d..98a6cb2 100644
--- a/miniJava/src/miniJava/SyntacticAnalyzer/Scanner.java
+++ b/miniJava/src/miniJava/SyntacticAnalyzer/Scanner.java
@@ -153,7 +153,7 @@ public class Scanner {
 	    			break;
 	    	}
     	}
-    	System.out.println(token.type);
+
     	return token;
     }
     
diff --git a/miniJava/src/miniJava/SyntacticAnalyzer/SourcePosition.java b/miniJava/src/miniJava/SyntacticAnalyzer/SourcePosition.java
new file mode 100644
index 0000000..38ddb6c
--- /dev/null
+++ b/miniJava/src/miniJava/SyntacticAnalyzer/SourcePosition.java
@@ -0,0 +1,12 @@
+package miniJava.SyntacticAnalyzer;
+
+public class SourcePosition {
+
+	public final int col;
+	public final int line;
+	
+	public SourcePosition(int line, int col) {
+		this.col = col;
+		this.line = line;
+	}
+}
diff --git a/miniJava/src/miniJava/SyntacticAnalyzer/Token.java b/miniJava/src/miniJava/SyntacticAnalyzer/Token.java
index f2593b2..7c78681 100644
--- a/miniJava/src/miniJava/SyntacticAnalyzer/Token.java
+++ b/miniJava/src/miniJava/SyntacticAnalyzer/Token.java
@@ -69,10 +69,10 @@ public class Token {
      }
 	 
 	public final TYPE type;
-	public final String attr;
+	public final String spelling;
 		
-	public Token(String attr, TYPE type) {
+	public Token(String spelling, TYPE type) {
 		this.type = type;
-		this.attr = attr;
+		this.spelling = spelling;
 	}
 }
diff --git a/miniJava/src/miniJava/SyntacticAnalyzer/grammar.txt b/miniJava/src/miniJava/grammar.txt
similarity index 89%
rename from miniJava/src/miniJava/SyntacticAnalyzer/grammar.txt
rename to miniJava/src/miniJava/grammar.txt
index 0cf2bc3..b0947d8 100644
--- a/miniJava/src/miniJava/SyntacticAnalyzer/grammar.txt
+++ b/miniJava/src/miniJava/grammar.txt
@@ -31,10 +31,10 @@ Statement ::=
 	| while (Expression) Statement
 	
 Expression ::=
-	Reference
-	| Reference ( ArgumentList? )
+	Reference ((ArgumentList?))?
 	| unop Expression
 	| Expression binop Expression
 	| ( Expression )
 	| num | true | false
-	| new (id() | int [ Expression ] | id [ Expression ] )
\ No newline at end of file
+	| new (id() | int [ Expression ] | id [ Expression ] )
+	
\ No newline at end of file
diff --git a/miniJava/src/miniJava/stratified.txt b/miniJava/src/miniJava/stratified.txt
new file mode 100644
index 0000000..fd62abf
--- /dev/null
+++ b/miniJava/src/miniJava/stratified.txt
@@ -0,0 +1,50 @@
+Program ::= (ClassDeclaration)* eot
+
+ClassDeclaration ::=   
+	class id  {       
+		(Declarators id (; | MethodDeclaration))*   
+	}
+	
+MethodDeclaration ::=
+	(ParameterList?) {
+		Statement* (return Expression ;)?
+	}
+	
+Declarators ::= (public | private)? static? Type
+
+Type ::= boolean | void | int ([])? | id ([])?
+
+ParameterList ::= Type id (, Type id)*
+
+ArgumentList ::= Expression (, Expression)*
+
+Reference ::= BaseRef (. id ([ Expression])?)*
+
+BaseRef ::= this | id ([ Expression])?
+
+Statement ::=
+	{Statement*}
+	| Type id = Expression;
+	| Reference = Expression;
+	| Reference ( ArgumentList? );
+	| if (Expression) Statement (else Statement)?
+	| while (Expression) Statement
+	
+Expression ::=
+	num | true | false
+	| ( Expression )
+	| new (id() | int [ Expression ] | id [ Expression ] )
+	| Reference ((ArgumentList?))?
+	| DExpression
+		
+DExpression ::= CExpression (|| CExpression)*
+CExpression ::= EExpression (&& EExpression)*
+EExpression ::= RExpression ((==|!=) RExpression)*
+RExpression ::= AExpression ((<=|<|>|>=) AExpression)*
+AExpression ::= MExpression ((+|-) MExpression)*
+MExpression ::= Expression ((*|/) Expression)*
+	
+	
+	
+	
+	
\ No newline at end of file
diff --git a/miniJava/test.java b/miniJava/test.java
index eb38ef4..b4ffe40 100644
--- a/miniJava/test.java
+++ b/miniJava/test.java
@@ -1,7 +1,12 @@
-// PA1 parse assign fail
-class Test {
+// Simple PA2 Example
+class PA2 {
 
-    void p(int a) {
-	that.this = 4;
-    }
+	public boolean c;
+	
+	public static void main(String[] args) {
+		if(x > 1)
+			x = 1 + 2 * x;
+		else 
+			b[3].a = 4;
+	}
 }
\ No newline at end of file