Pretty printing for TypeCheckSimp, start for symbol table

1 files changed, 631 insertions, 311 deletions

diff --git a/minijava/TypeCheckSimp.java b/minijava/TypeCheckSimp.java
index 01f8b27..ab5d8c9 100644
--- a/minijava/TypeCheckSimp.java
+++ b/minijava/TypeCheckSimp.java
@@ -8,58 +8,114 @@ import java.util.*;
  * Provides default methods which visit each node in the tree in depth-first
  * order.  Your visitors may extend this class.
  */
-public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,String>> {
-
-    private void print_filter(String message) {
-	boolean debug = true;
-	if (debug)
-	    System.out.println(message);
+public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,TypeEnum>> {
+
+    private int offset;
+
+    private void printNode(Node n, HashMap<String,TypeEnum> argu, boolean enter, TypeEnum consensus) {
+	for (int i=0; i < this.offset; ++i)
+            System.out.print(".");
+	if (enter)
+            System.out.print("Visiting ");
+        else
+            System.out.print("Leaving ");
+        System.out.print(n.getClass().getSimpleName());
+	if (!enter) {
+	    if (consensus == TypeEnum.ERROR)
+		System.out.print(" did not type check.");
+	    else
+		System.out.print(" found type " + consensus);
+	}
+	System.out.println();
     }
+
     //
     // Auto class visitors--probably don't need to be overridden.
     //
-    public TypeInstance visit(NodeList n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	int _count=0;
-	for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
-	    e.nextElement().accept(this,argu);
-	    _count++;
-	}
-	return _ret;
-    }
-
-    public TypeInstance visit(NodeListOptional n, HashMap<String,String> argu) {
-	if ( n.present() ) {
-	    TypeInstance _ret=null;
-	    int _count=0;
-	    for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
-		e.nextElement().accept(this,argu);
-		_count++;
-	    }
-	    return _ret;
-	}
-	else
-	    return null;
+    public TypeInstance visit(NodeList n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = new TypeInstance(TypeEnum.CHECK);
+        int _count=0;
+        for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
+            TypeInstance node = e.nextElement().accept(this,argu);
+            e.nextElement().accept(this,argu);
+            if (node.get_type() == TypeEnum.ERROR)
+                ret = node;
+            _count++;
+        }
+	
+	this.printNode(n, argu, false, ret.get_type()); 
+	--this.offset;
+        return ret;
+    }
+
+    public TypeInstance visit(NodeListOptional n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+	TypeInstance ret;
+        if ( n.present() ) { // FIXME "present" seems to check if any nodes exist at all!
+            ret = new TypeInstance(TypeEnum.CHECK);
+            int _count=0;
+            for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
+                TypeInstance node = e.nextElement().accept(this,argu);
+                if (node.get_type() == TypeEnum.ERROR)
+                    ret = node;
+                _count++;
+            }
+        }
+        else
+            ret = new TypeInstance(TypeEnum.CHECK); // FIXME used to read 'null'
+	
+	this.printNode(n, argu, false, ret.get_type()); 
+	--this.offset;
+	return ret;
     }
 
-    public TypeInstance visit(NodeOptional n, HashMap<String,String> argu) {
-	if ( n.present() )
-	    return n.node.accept(this,argu);
-	else
-	    return null;
+    // FIXME
+    public TypeInstance visit(NodeOptional n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+
+	TypeInstance ret;
+	
+        if ( n.present() )
+            ret = n.node.accept(this,argu);
+        else
+            ret = new TypeInstance(TypeEnum.CHECK);
+	
+	this.printNode(n, argu, false, ret.get_type()); 
+	--this.offset;
+	return ret;
     }
 
-    public TypeInstance visit(NodeSequence n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	int _count=0;
-	for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
-	    e.nextElement().accept(this,argu);
-	    _count++;
-	}
-	return _ret;
+    public TypeInstance visit(NodeSequence n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = new TypeInstance(TypeEnum.CHECK);
+        int _count=0;
+        for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
+            TypeInstance node = e.nextElement().accept(this,argu);
+            if (node.get_type() == TypeEnum.ERROR)
+                ret = node;
+            _count++;
+        }
+
+	this.printNode(n, argu, false, ret.get_type()); 
+	--this.offset;
+        return ret;
     }
 
-    public TypeInstance visit(NodeToken n, HashMap<String,String> argu) { return null; }
+    public TypeInstance visit(NodeToken n, HashMap<String,TypeEnum> argu) {
+	// A fixed string token. '⌣'
+	++this.offset;
+	// this.printNode(n, argu, false, null); 
+	--this.offset;
+        return null;
+    }
 
     //
     // User-generated visitor methods below
@@ -70,11 +126,17 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> ( TypeDeclaration() )*
      * f2 -> <EOF>
      */
-    public TypeInstance visit(Goal n, HashMap<String,String> argu) {
-	TypeInstance ret = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	return ret;
+    public TypeInstance visit(Goal n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+	
+	this.printNode(n, argu, false, ret.get_type()); 
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -97,34 +159,47 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f16 -> "}"
      * f17 -> "}"
      */
-    public TypeInstance visit(MainClass n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	TypeInstance name = n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	n.f4.accept(this, argu);
-	n.f5.accept(this, argu);
-	n.f6.accept(this, argu);
-	n.f7.accept(this, argu);
-	n.f8.accept(this, argu);
-	n.f9.accept(this, argu);
-	n.f10.accept(this, argu);
-	TypeInstance args = n.f11.accept(this, argu);
-	n.f12.accept(this, argu);
-	n.f13.accept(this, argu);
-	TypeInstance var_dec = n.f14.accept(this, argu);
-	TypeInstance stmt = n.f15.accept(this, argu);
-	n.f16.accept(this, argu);
-	n.f17.accept(this, argu);
-	return stmt;
+    public TypeInstance visit(MainClass n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance name = n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        n.f4.accept(this, argu);
+        n.f5.accept(this, argu);
+        n.f6.accept(this, argu);
+        n.f7.accept(this, argu);
+        n.f8.accept(this, argu);
+        n.f9.accept(this, argu);
+        n.f10.accept(this, argu);
+        TypeInstance args = n.f11.accept(this, argu);
+        n.f12.accept(this, argu);
+        n.f13.accept(this, argu);
+        TypeInstance var_dec = n.f14.accept(this, argu);
+        TypeInstance stmt = n.f15.accept(this, argu);
+        n.f16.accept(this, argu);
+        n.f17.accept(this, argu);
+
+	this.printNode(n, argu, false, stmt.get_type());
+	--this.offset;
+        return stmt;
     }
 
     /**
      * f0 -> ClassDeclaration()
      *               | ClassExtendsDeclaration()
      */
-    public TypeInstance visit(TypeDeclaration n, HashMap<String,String> argu) {
-	return n.f0.accept(this, argu);
+    public TypeInstance visit(TypeDeclaration n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = n.f0.accept(this, argu);
+	
+	this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -135,15 +210,19 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f4 -> ( MethodDeclaration() )*
      * f5 -> "}"
      */
-    public TypeInstance visit(ClassDeclaration n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	n.f4.accept(this, argu);
-	n.f5.accept(this, argu);
-	return _ret;
+    public TypeInstance visit(ClassDeclaration n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance _ret=null;
+        n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        n.f4.accept(this, argu);
+        n.f5.accept(this, argu);
+	--this.offset;
+        return _ret;
     }
 
     /**
@@ -156,17 +235,21 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f6 -> ( MethodDeclaration() )*
      * f7 -> "}"
      */
-    public TypeInstance visit(ClassExtendsDeclaration n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	n.f4.accept(this, argu);
-	n.f5.accept(this, argu);
-	n.f6.accept(this, argu);
-	n.f7.accept(this, argu);
-	return _ret;
+    public TypeInstance visit(ClassExtendsDeclaration n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance _ret=null;
+        n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        n.f4.accept(this, argu);
+        n.f5.accept(this, argu);
+        n.f6.accept(this, argu);
+        n.f7.accept(this, argu);
+	--this.offset;
+        return _ret;
     }
 
     // FIXME
@@ -175,13 +258,20 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> Identifier()
      * f2 -> ";"
      */
-    public TypeInstance visit(VarDeclaration n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	return new TypeInstance(TypeEnum.CHECK);
+    public TypeInstance visit(VarDeclaration n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+	
+	this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
+    // FIXME
     /**
      * f0 -> "public"
      * f1 -> Type()
@@ -197,55 +287,84 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f11 -> ";"
      * f12 -> "}"
      */
-    public TypeInstance visit(MethodDeclaration n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	n.f4.accept(this, argu);
-	n.f5.accept(this, argu);
-	n.f6.accept(this, argu);
-	n.f7.accept(this, argu);
-	n.f8.accept(this, argu);
-	n.f9.accept(this, argu);
-	n.f10.accept(this, argu);
-	n.f11.accept(this, argu);
-	n.f12.accept(this, argu);
-	return _ret;
+    public TypeInstance visit(MethodDeclaration n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance ret_type = n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        n.f4.accept(this, argu);
+        n.f5.accept(this, argu);
+        n.f6.accept(this, argu);
+        n.f7.accept(this, argu);
+        TypeInstance stmt = n.f8.accept(this, argu);
+        n.f9.accept(this, argu);
+        TypeInstance retur = n.f10.accept(this, argu);
+        n.f11.accept(this, argu);
+        n.f12.accept(this, argu);
+	TypeInstance ret = (stmt.equal_type(ret_type) &&
+			    stmt.get_type() == TypeEnum.CHECK) ?
+	    new TypeInstance(TypeEnum.CHECK) :
+	    new TypeInstance(TypeEnum.ERROR);
+	
+	this.printNode(n, argu, false, ret.get_type()); 
+	--this.offset;
+        return ret;
     }
 
     /**
      * f0 -> FormalParameter()
      * f1 -> ( FormalParameterRest() )*
      */
-    public TypeInstance visit(FormalParameterList n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	return _ret;
+    public TypeInstance visit(FormalParameterList n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance _ret=null;
+        TypeInstance para1 = n.f0.accept(this, argu);
+        TypeInstance parar = n.f1.accept(this, argu);
+        TypeInstance ret = (para1.get_type() == TypeEnum.CHECK &&
+			    parar.get_type() == TypeEnum.CHECK) ?
+	    new TypeInstance(TypeEnum.CHECK) :
+	    new TypeInstance(TypeEnum.ERROR);
+	
+	this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
      * f0 -> Type()
      * f1 -> Identifier()
      */
-    public TypeInstance visit(FormalParameter n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	return _ret;
+    public TypeInstance visit(FormalParameter n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+	
+	this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
      * f0 -> ","
      * f1 -> FormalParameter()
      */
-    public TypeInstance visit(FormalParameterRest n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	return _ret;
+    public TypeInstance visit(FormalParameterRest n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance ret = n.f1.accept(this, argu);
+	
+	this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -254,8 +373,15 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      *               | IntegerType()
      *               | Identifier()
      */
-    public TypeInstance visit(Type n, HashMap<String,String> argu) {
-	return n.f0.accept(this, argu);
+    public TypeInstance visit(Type n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+	TypeInstance ret =  n.f0.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -263,26 +389,45 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> "["
      * f2 -> "]"
      */
-    public TypeInstance visit(ArrayType n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	return new TypeInstance(TypeEnum.int_array);
+    public TypeInstance visit(ArrayType n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        TypeInstance ret = new TypeInstance(TypeEnum.int_array);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
      * f0 -> "boolean"
      */
-    public TypeInstance visit(BooleanType n, HashMap<String,String> argu) {
-	return n.f0.accept(this, argu);
+    public TypeInstance visit(BooleanType n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret =  new TypeInstance(TypeEnum.bool);
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
      * f0 -> "int"
      */
-    public TypeInstance visit(IntegerType n, HashMap<String,String> argu) {
-	return n.f0.accept(this, argu);
+    public TypeInstance visit(IntegerType n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret =  new TypeInstance(TypeEnum.integer);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -293,8 +438,15 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      *               | WhileStatement()
      *               | PrintStatement()
      */
-    public TypeInstance visit(Statement n, HashMap<String,String> argu) {
-	return n.f0.accept(this, argu);
+    public TypeInstance visit(Statement n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret =  n.f0.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -302,11 +454,17 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> ( Statement() )*
      * f2 -> "}"
      */
-    public TypeInstance visit(Block n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	TypeInstance ret = n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	return ret;
+    public TypeInstance visit(Block n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance ret = n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -315,14 +473,21 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f2 -> Expression()
      * f3 -> ";"
      */
-    public TypeInstance visit(AssignmentStatement n, HashMap<String,String> argu) {
-	TypeInstance lhs = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance rhs = n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	return (lhs.equal_type(rhs)) ?
-	    new TypeInstance(TypeEnum.CHECK) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(AssignmentStatement n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance lhs = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance rhs = n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        TypeInstance ret = (lhs.equal_type(rhs)) ?
+            new TypeInstance(TypeEnum.CHECK) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -334,18 +499,25 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f5 -> Expression() //int
      * f6 -> ";"
      */
-    public TypeInstance visit(ArrayAssignmentStatement n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance index = n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	n.f4.accept(this, argu);
-	TypeInstance value = n.f5.accept(this, argu);
-	n.f6.accept(this, argu);
-	return (index.get_type() == TypeEnum.integer &&
-		value.get_type() == TypeEnum.integer) ?
-	    new TypeInstance(TypeEnum.CHECK) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(ArrayAssignmentStatement n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance index = n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        n.f4.accept(this, argu);
+        TypeInstance value = n.f5.accept(this, argu);
+        n.f6.accept(this, argu);
+        TypeInstance ret =  (index.get_type() == TypeEnum.integer &&
+                             value.get_type() == TypeEnum.integer) ?
+            new TypeInstance(TypeEnum.CHECK) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -357,18 +529,27 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f5 -> "else"
      * f6 -> Statement()
      */
-    public TypeInstance visit(IfStatement n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance expr = n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	TypeInstance stmt1 = n.f4.accept(this, argu);
-	n.f5.accept(this, argu);
-	TypeInstance stmt2 = n.f6.accept(this, argu);
-	return (expr.get_type() == TypeEnum.bool &&
-		stmt1.get_type() == stmt2.get_type() == TypeEnum.CHECK) ?
-	    new TypeInstance(TypeEnum.CHECK) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(IfStatement n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance expr = n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        TypeInstance stmt1 = n.f4.accept(this, argu);
+        n.f5.accept(this, argu);
+        TypeInstance stmt2 = n.f6.accept(this, argu);
+        TypeInstance ret = (expr.get_type() == TypeEnum.bool &&
+                            stmt1.get_type() == stmt2.get_type() &&
+                            stmt1.get_type() == TypeEnum.CHECK) ?
+            new TypeInstance(TypeEnum.CHECK) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
+
     }
 
     /**
@@ -378,16 +559,23 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f3 -> ")"
      * f4 -> Statement()
      */
-    public TypeInstance visit(WhileStatement n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance expr = n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	TypeInstance stmt = n.f4.accept(this, argu);
-	return (expr.get_type() == TypeEnum.bool &&
-		stmt.get_type() == TypeEnum.CHECK) ?
-	    new TypeInstance(TypeEnum.CHECK) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(WhileStatement n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance expr = n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        TypeInstance stmt = n.f4.accept(this, argu);
+        TypeInstance ret = (expr.get_type() == TypeEnum.bool &&
+                            stmt.get_type() == TypeEnum.CHECK) ?
+            new TypeInstance(TypeEnum.CHECK) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -397,15 +585,22 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f3 -> ")"
      * f4 -> ";"
      */
-    public TypeInstance visit(PrintStatement n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance ret = n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	n.f4.accept(this, argu);
-	return (ret.get_type() == TypeEnum.integer) ?
-	    new TypeInstance(TypeEnum.CHECK) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(PrintStatement n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance ret = n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        n.f4.accept(this, argu);
+        ret = (ret.get_type() == TypeEnum.integer) ?
+            new TypeInstance(TypeEnum.CHECK) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -419,8 +614,15 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      *               | MessageSend()
      *               | PrimaryExpression()
      */
-    public TypeInstance visit(Expression n, HashMap<String,String> argu) {
-	return n.f0.accept(this, argu);
+    public TypeInstance visit(Expression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = n.f0.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -428,14 +630,21 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> "&&"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(AndExpression n, HashMap<String,String> argu) {
-	TypeInstance oper1 = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance oper2 = n.f2.accept(this, argu);
-	return (oper1.get_type() == TypeEnum.bool &&
-		oper2.get_type() == TypeEnum.bool) ?
-	    new TypeInstance(TypeEnum.bool) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(AndExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance oper1 = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance oper2 = n.f2.accept(this, argu);
+        TypeInstance ret = (oper1.get_type() == TypeEnum.bool &&
+                            oper2.get_type() == TypeEnum.bool) ?
+            new TypeInstance(TypeEnum.bool) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -443,15 +652,21 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> "<"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(CompareExpression n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	TypeInstance oper1 = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance oper2 = n.f2.accept(this, argu);
-	return (oper1.get_type() == TypeEnum.integer &&
-		oper2.get_type() == TypeEnum.integer) ?
-	    new TypeInstance(TypeEnum.bool) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(CompareExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance oper1 = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance oper2 = n.f2.accept(this, argu);
+        TypeInstance ret = (oper1.get_type() == TypeEnum.integer &&
+                            oper2.get_type() == TypeEnum.integer) ?
+            new TypeInstance(TypeEnum.bool) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -459,14 +674,21 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> "+"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(PlusExpression n, HashMap<String,String> argu) {
-	TypeInstance oper1 = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance oper2 = n.f2.accept(this, argu);
-	return (oper1.get_type() == TypeEnum.integer &&
-		oper2.get_type() == TypeEnum.integer) ?
-	    new TypeInstance(TypeEnum.integer) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(PlusExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance oper1 = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance oper2 = n.f2.accept(this, argu);
+        TypeInstance ret = (oper1.get_type() == TypeEnum.integer &&
+                            oper2.get_type() == TypeEnum.integer) ?
+            new TypeInstance(TypeEnum.integer) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -474,14 +696,21 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> "-"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(MinusExpression n, HashMap<String,String> argu) {
-	TypeInstance oper1 = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance oper2 = n.f2.accept(this, argu);
-	return (oper1.get_type() == TypeEnum.integer &&
-		oper2.get_type() == TypeEnum.integer) ?
-	    new TypeInstance(TypeEnum.integer) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(MinusExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance oper1 = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance oper2 = n.f2.accept(this, argu);
+        TypeInstance ret = (oper1.get_type() == TypeEnum.integer &&
+                            oper2.get_type() == TypeEnum.integer) ?
+            new TypeInstance(TypeEnum.integer) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -489,14 +718,21 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> "*"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(TimesExpression n, HashMap<String,String> argu) {
-	TypeInstance oper1 = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance oper2 = n.f2.accept(this, argu);
-	return (oper1.get_type() == TypeEnum.integer &&
-		oper2.get_type() == TypeEnum.integer) ?
-	    new TypeInstance(TypeEnum.integer) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(TimesExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance oper1 = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance oper2 = n.f2.accept(this, argu);
+        TypeInstance ret = (oper1.get_type() == TypeEnum.integer &&
+                            oper2.get_type() == TypeEnum.integer) ?
+            new TypeInstance(TypeEnum.integer) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -505,16 +741,22 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f2 -> PrimaryExpression()
      * f3 -> "]"
      */
-    public TypeInstance visit(ArrayLookup n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	TypeInstance array = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	TypeInstance index = n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	return (array.get_type() == TypeEnum.int_array &&
-		index.get_type() == TypeEnum.integer) ?
-	    new TypeInstance(TypeEnum.integer) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(ArrayLookup n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance array = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        TypeInstance index = n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        TypeInstance ret = (array.get_type() == TypeEnum.int_array &&
+                            index.get_type() == TypeEnum.integer) ?
+            new TypeInstance(TypeEnum.integer) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -522,14 +764,19 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> "."
      * f2 -> "length"
      */
-    public TypeInstance visit(ArrayLength n, HashMap<String,String> argu) {
-	// can only act on an array
-	TypeInstance _ret=null;
-	TypeInstance ret = n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	return (ret.get_type() == TypeEnum.int_array) ? new TypeInstance(TypeEnum.integer) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(ArrayLength n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        ret = (ret.get_type() == TypeEnum.int_array) ? new TypeInstance(TypeEnum.integer) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -540,15 +787,19 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f4 -> ( ExpressionList() )?
      * f5 -> ")"
      */
-    public TypeInstance visit(MessageSend n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	n.f4.accept(this, argu);
-	n.f5.accept(this, argu);
-	return _ret;
+    public TypeInstance visit(MessageSend n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance _ret=null;
+        n.f0.accept(this, argu);
+        n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        n.f4.accept(this, argu);
+        n.f5.accept(this, argu);
+	--this.offset;
+        return _ret;
     }
 
     // FIXME
@@ -556,21 +807,31 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f0 -> Expression()
      * f1 -> ( ExpressionRest() )*
      */
-    public TypeInstance visit(ExpressionList n, HashMap<String,String> argu) {
+    public TypeInstance visit(ExpressionList n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
 	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	n.f1.accept(this, argu);
-	return _ret;
+        TypeInstance expr1 = n.f0.accept(this, argu);
+        TypeInstance exprr =  n.f1.accept(this, argu);
+	--this.offset;
+        return _ret;
     }
 
     /**
      * f0 -> ","
      * f1 -> Expression()
      */
-    public TypeInstance visit(ExpressionRest n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	TypeInstance ret = n.f1.accept(this, argu);
-	return ret;
+    public TypeInstance visit(ExpressionRest n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance ret = n.f1.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -584,46 +845,81 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      *               | NotExpression()
      *               | BracketExpression()
      */
-    public TypeInstance visit(PrimaryExpression n, HashMap<String,String> argu) {
-	return n.f0.accept(this, argu);
+    public TypeInstance visit(PrimaryExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        TypeInstance ret = n.f0.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
      * f0 -> <INTEGER_LITERAL>
      */
-    public TypeInstance visit(IntegerLiteral n, HashMap<String,String> argu) {
-	return new TypeInstance(TypeEnum.integer);
+    public TypeInstance visit(IntegerLiteral n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        this.printNode(n, argu, false, TypeEnum.integer);
+	--this.offset;
+        return new TypeInstance(TypeEnum.integer);
     }
 
     /**
      * f0 -> "true"
      */
-    public TypeInstance visit(TrueLiteral n, HashMap<String,String> argu) {
-	return new TypeInstance(TypeEnum.bool);
+    public TypeInstance visit(TrueLiteral n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        this.printNode(n, argu, false, TypeEnum.bool);
+	--this.offset;
+        return new TypeInstance(TypeEnum.bool);
     }
 
     /**
      * f0 -> "false"
      */
-    public TypeInstance visit(FalseLiteral n, HashMap<String,String> argu) {
-	return new TypeInstance(TypeEnum.bool);
+    public TypeInstance visit(FalseLiteral n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        this.printNode(n, argu, false, TypeEnum.bool);
+	--this.offset;
+        return new TypeInstance(TypeEnum.bool);
     }
 
     /**
      * f0 -> <IDENTIFIER>
      */
-    public TypeInstance visit(Identifier n, HashMap<String,String> argu) {
-	return new TypeInstance(TypeEnum.CHECK);
+    public TypeInstance visit(Identifier n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+
+	TypeInstance ret = new TypeInstance(argu.get(n.f0.tokenImage));
+	
+        this.printNode(n, argu, false, TypeEnum.CHECK);
+	--this.offset;
+        return new TypeInstance(TypeEnum.CHECK);
     }
 
     //FIXME
     /**
      * f0 -> "this"
      */
-    public TypeInstance visit(ThisExpression n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	return _ret;
+    public TypeInstance visit(ThisExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+	TypeInstance ret = new TypeInstance(TypeEnum.CHECK);
+	
+	this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -633,15 +929,21 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f3 -> Expression()
      * f4 -> "]"
      */
-    public TypeInstance visit(ArrayAllocationExpression n, HashMap<String,String> argu) {
-	TypeInstance _ret=null;
-	n.f0.accept(this, argu);
-	TypeInstance ret = n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	n.f4.accept(this, argu);
-	return (ret.get_type() == TypeEnum.integer) ? new TypeInstance(TypeEnum.int_array) :
-	    new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(ArrayAllocationExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance ret = n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+        n.f4.accept(this, argu);
+        ret = (ret.get_type() == TypeEnum.integer) ? new TypeInstance(TypeEnum.int_array) :
+            new TypeInstance(TypeEnum.ERROR);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
@@ -650,22 +952,34 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f2 -> "("
      * f3 -> ")"
      */
-    public TypeInstance visit(AllocationExpression n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	TypeInstance ret = n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	n.f3.accept(this, argu);
-	return ret;
+    public TypeInstance visit(AllocationExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance ret = n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+        n.f3.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
     /**
      * f0 -> "!"
      * f1 -> Expression()
      */
-    public TypeInstance visit(NotExpression n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	TypeInstance ret = n.f1.accept(this, argu);
-	return (ret.get_type() == TypeEnum.bool) ? ret : new TypeInstance(TypeEnum.ERROR);
+    public TypeInstance visit(NotExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance ret = n.f1.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return (ret.get_type() == TypeEnum.bool) ? ret : new TypeInstance(TypeEnum.ERROR);
     }
 
     /**
@@ -673,11 +987,17 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Stri
      * f1 -> Expression()
      * f2 -> ")"
      */
-    public TypeInstance visit(BracketExpression n, HashMap<String,String> argu) {
-	n.f0.accept(this, argu);
-	TypeInstance ret = n.f1.accept(this, argu);
-	n.f2.accept(this, argu);
-	return ret;
+    public TypeInstance visit(BracketExpression n, HashMap<String,TypeEnum> argu) {
+	++this.offset;
+	this.printNode(n, argu, true, null);
+	
+        n.f0.accept(this, argu);
+        TypeInstance ret = n.f1.accept(this, argu);
+        n.f2.accept(this, argu);
+	
+        this.printNode(n, argu, false, ret.get_type());
+	--this.offset;
+        return ret;
     }
 
 }