Added minor classname functionality to ST

1 files changed, 118 insertions, 113 deletions

diff --git a/minijava/TypeCheckSimp.java b/minijava/TypeCheckSimp.java
index f9e71bd..4ad0639 100644
--- a/minijava/TypeCheckSimp.java
+++ b/minijava/TypeCheckSimp.java
@@ -8,11 +8,11 @@ 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,TypeEnum>> {
+public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,TypeInstance>> {
 
     private int offset;
 
-    private void printNode(Node n, HashMap<String,TypeEnum> argu, boolean enter, TypeEnum consensus) {
+    private void printNode(Node n, HashMap<String,TypeInstance> argu, boolean enter, TypeEnum consensus) {
         for (int i=0; i < this.offset; ++i)
             System.out.print(".");
         if (enter)
@@ -32,11 +32,11 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
     //
     // Auto class visitors--probably don't need to be overridden.
     //
-    public TypeInstance visit(NodeList n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(NodeList n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
-        TypeInstance ret = new TypeInstance(TypeEnum.CHECK);
+        TypeInstance ret = new TypeInstance(null, TypeEnum.CHECK);
         int _count=0;
         for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
             TypeInstance node = e.nextElement().accept(this,argu);
@@ -51,13 +51,13 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         return ret;
     }
 
-    public TypeInstance visit(NodeListOptional n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(NodeListOptional n, HashMap<String,TypeInstance> 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);
+        if ( n.present() ) {
+            ret = new TypeInstance(null, TypeEnum.CHECK);
             int _count=0;
             for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
                 TypeInstance node = e.nextElement().accept(this,argu);
@@ -67,7 +67,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
             }
         }
         else
-            ret = new TypeInstance(TypeEnum.CHECK); // FIXME used to read 'null'
+            ret = new TypeInstance(null, TypeEnum.CHECK);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -75,7 +75,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
     }
 
     // FIXME
-    public TypeInstance visit(NodeOptional n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(NodeOptional n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -84,18 +84,18 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         if ( n.present() )
             ret = n.node.accept(this,argu);
         else
-            ret = new TypeInstance(TypeEnum.CHECK);
+            ret = new TypeInstance(null, TypeEnum.CHECK);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
         return ret;
     }
 
-    public TypeInstance visit(NodeSequence n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(NodeSequence n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
-        TypeInstance ret = new TypeInstance(TypeEnum.CHECK);
+        TypeInstance ret = new TypeInstance(null, TypeEnum.CHECK);
         int _count=0;
         for ( Enumeration<Node> e = n.elements(); e.hasMoreElements(); ) {
             TypeInstance node = e.nextElement().accept(this,argu);
@@ -109,7 +109,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         return ret;
     }
 
-    public TypeInstance visit(NodeToken n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(NodeToken n, HashMap<String,TypeInstance> argu) {
         // A fixed string token. '⌣'
         ++this.offset;
         // this.printNode(n, argu, false, null);
@@ -126,7 +126,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> ( TypeDeclaration() )*
      * f2 -> <EOF>
      */
-    public TypeInstance visit(Goal n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(Goal n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -159,7 +159,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f16 -> "}"
      * f17 -> "}"
      */
-    public TypeInstance visit(MainClass n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(MainClass n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -174,7 +174,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         n.f8.accept(this, argu);
         n.f9.accept(this, argu);
         n.f10.accept(this, argu);
-        TypeInstance args = n.f11.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);
@@ -191,7 +191,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f0 -> ClassDeclaration()
      *               | ClassExtendsDeclaration()
      */
-    public TypeInstance visit(TypeDeclaration n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(TypeDeclaration n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -210,19 +210,25 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f4 -> ( MethodDeclaration() )*
      * f5 -> "}"
      */
-    public TypeInstance visit(ClassDeclaration n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ClassDeclaration n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
-        TypeInstance _ret=null;
         n.f0.accept(this, argu);
-        n.f1.accept(this, argu);
+        TypeInstance id = n.f1.accept(this, argu);
         n.f2.accept(this, argu);
-        n.f3.accept(this, argu);
-        n.f4.accept(this, argu);
+        TypeInstance vars = n.f3.accept(this, argu);
+        TypeInstance mehs = n.f4.accept(this, argu);
         n.f5.accept(this, argu);
+        TypeInstance ret = (id.get_type() == TypeEnum.classname &&
+                            vars.has_checked() &&
+                            mehs.has_checked()) ?
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
+
+        this.printNode(n, argu, false, ret.get_type());
         --this.offset;
-        return _ret;
+        return ret;
     }
 
     /**
@@ -235,7 +241,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f6 -> ( MethodDeclaration() )*
      * f7 -> "}"
      */
-    public TypeInstance visit(ClassExtendsDeclaration n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ClassExtendsDeclaration n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -258,7 +264,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> Identifier()
      * f2 -> ";"
      */
-    public TypeInstance visit(VarDeclaration n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(VarDeclaration n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -287,7 +293,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f11 -> ";"
      * f12 -> "}"
      */
-    public TypeInstance visit(MethodDeclaration n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(MethodDeclaration n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -305,9 +311,9 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+                            stmt.has_checked()) ?
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -318,17 +324,17 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f0 -> FormalParameter()
      * f1 -> ( FormalParameterRest() )*
      */
-    public TypeInstance visit(FormalParameterList n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(FormalParameterList n, HashMap<String,TypeInstance> 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);
+        TypeInstance ret = (para1.has_checked() &&
+                            parar.has_checked()) ?
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -339,7 +345,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f0 -> Type()
      * f1 -> Identifier()
      */
-    public TypeInstance visit(FormalParameter n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(FormalParameter n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -355,7 +361,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f0 -> ","
      * f1 -> FormalParameter()
      */
-    public TypeInstance visit(FormalParameterRest n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(FormalParameterRest n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -373,7 +379,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      *               | IntegerType()
      *               | Identifier()
      */
-    public TypeInstance visit(Type n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(Type n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -389,11 +395,11 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> "["
      * f2 -> "]"
      */
-    public TypeInstance visit(ArrayType n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ArrayType n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
-        TypeInstance ret = new TypeInstance(TypeEnum.int_array);
+        TypeInstance ret = new TypeInstance(null, TypeEnum.int_array);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -403,11 +409,11 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
     /**
      * f0 -> "boolean"
      */
-    public TypeInstance visit(BooleanType n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(BooleanType n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
-        TypeInstance ret =  new TypeInstance(TypeEnum.bool);
+        TypeInstance ret =  new TypeInstance(null, TypeEnum.bool);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -417,11 +423,11 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
     /**
      * f0 -> "int"
      */
-    public TypeInstance visit(IntegerType n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(IntegerType n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
-        TypeInstance ret =  new TypeInstance(TypeEnum.integer);
+        TypeInstance ret =  new TypeInstance(null, TypeEnum.integer);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -436,7 +442,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      *               | WhileStatement()
      *               | PrintStatement()
      */
-    public TypeInstance visit(Statement n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(Statement n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -452,7 +458,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> ( Statement() )*
      * f2 -> "}"
      */
-    public TypeInstance visit(Block n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(Block n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -475,7 +481,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f2 -> Expression()
      * f3 -> ";"
      */
-    public TypeInstance visit(AssignmentStatement n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(AssignmentStatement n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -484,8 +490,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -504,12 +510,11 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f5 -> Expression()
      * f6 -> ";"
      */
-    public TypeInstance visit(ArrayAssignmentStatement n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ArrayAssignmentStatement n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
-        TypeInstance id = new TypeInstance(argu.get(n.f0.f0.tokenImage));
-        n.f0.accept(this, argu);
+        TypeInstance id = n.f0.accept(this, argu);
         n.f1.accept(this, argu);
         TypeInstance index = n.f2.accept(this, argu);
         n.f3.accept(this, argu);
@@ -519,8 +524,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         TypeInstance ret =  (id.get_type() == TypeEnum.int_array &&
                              index.get_type() == TypeEnum.integer &&
                              value.get_type() == TypeEnum.integer) ?
-            new TypeInstance(TypeEnum.CHECK) :
-            new TypeInstance(TypeEnum.ERROR);
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -538,7 +543,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f5 -> "else"
      * f6 -> Statement()
      */
-    public TypeInstance visit(IfStatement n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(IfStatement n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -551,9 +556,9 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+                            stmt1.has_checked()) ?
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -570,7 +575,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f3 -> ")"
      * f4 -> Statement()
      */
-    public TypeInstance visit(WhileStatement n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(WhileStatement n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -580,9 +585,9 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+                            stmt.has_checked()) ?
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -598,7 +603,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f3 -> ")"
      * f4 -> ";"
      */
-    public TypeInstance visit(PrintStatement n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(PrintStatement n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -608,8 +613,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         n.f3.accept(this, argu);
         n.f4.accept(this, argu);
         ret = (ret.get_type() == TypeEnum.integer) ?
-            new TypeInstance(TypeEnum.CHECK) :
-            new TypeInstance(TypeEnum.ERROR);
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -627,7 +632,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      *               | MessageSend()
      *               | PrimaryExpression()
      */
-    public TypeInstance visit(Expression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(Expression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -645,7 +650,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> "&&"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(AndExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(AndExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -654,8 +659,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+            new TypeInstance(null, TypeEnum.bool) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -669,7 +674,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> "<"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(CompareExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(CompareExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -678,8 +683,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+            new TypeInstance(null, TypeEnum.bool) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -693,7 +698,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> "+"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(PlusExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(PlusExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -702,8 +707,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+            new TypeInstance(null, TypeEnum.integer) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -717,7 +722,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> "-"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(MinusExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(MinusExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -726,8 +731,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+            new TypeInstance(null, TypeEnum.integer) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -741,7 +746,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> "*"
      * f2 -> PrimaryExpression()
      */
-    public TypeInstance visit(TimesExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(TimesExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -750,8 +755,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+            new TypeInstance(null, TypeEnum.integer) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -767,7 +772,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f2 -> PrimaryExpression()
      * f3 -> "]"
      */
-    public TypeInstance visit(ArrayLookup n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ArrayLookup n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -777,8 +782,8 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+            new TypeInstance(null, TypeEnum.integer) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -792,15 +797,15 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> "."
      * f2 -> "length"
      */
-    public TypeInstance visit(ArrayLength n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ArrayLength n, HashMap<String,TypeInstance> 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);
+        ret = (ret.get_type() == TypeEnum.int_array) ? new TypeInstance(null, TypeEnum.integer) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -818,7 +823,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f4 -> ( ExpressionList() )?
      * f5 -> ")"
      */
-    public TypeInstance visit(MessageSend n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(MessageSend n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -838,16 +843,16 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f0 -> Expression()
      * f1 -> ( ExpressionRest() )*
      */
-    public TypeInstance visit(ExpressionList n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ExpressionList n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
         TypeInstance expr1 = n.f0.accept(this, argu);
         TypeInstance exprr =  n.f1.accept(this, argu);
-        TypeInstance ret = (expr1.get_type() == TypeEnum.CHECK &&
-                            exprr.get_type() == TypeEnum.CHECK) ?
-            new TypeInstance(TypeEnum.CHECK) :
-            new TypeInstance(TypeEnum.ERROR);
+        TypeInstance ret = (expr1.has_checked() &&
+                            exprr.has_checked()) ?
+            new TypeInstance(null, TypeEnum.CHECK) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -858,7 +863,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f0 -> ","
      * f1 -> Expression()
      */
-    public TypeInstance visit(ExpressionRest n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ExpressionRest n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -881,7 +886,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      *               | NotExpression()
      *               | BracketExpression()
      */
-    public TypeInstance visit(PrimaryExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(PrimaryExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -898,13 +903,13 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      *
      * f0 -> <INTEGER_LITERAL>
      */
-    public TypeInstance visit(IntegerLiteral n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(IntegerLiteral n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
         this.printNode(n, argu, false, TypeEnum.integer);
         --this.offset;
-        return new TypeInstance(TypeEnum.integer);
+        return new TypeInstance(null, TypeEnum.integer);
     }
 
     /**
@@ -912,13 +917,13 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      *
      * f0 -> "true"
      */
-    public TypeInstance visit(TrueLiteral n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(TrueLiteral n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
         this.printNode(n, argu, false, TypeEnum.bool);
         --this.offset;
-        return new TypeInstance(TypeEnum.bool);
+        return new TypeInstance(null, TypeEnum.bool);
     }
 
     /**
@@ -926,13 +931,13 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      *
      * f0 -> "false"
      */
-    public TypeInstance visit(FalseLiteral n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(FalseLiteral n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
         this.printNode(n, argu, false, TypeEnum.bool);
         --this.offset;
-        return new TypeInstance(TypeEnum.bool);
+        return new TypeInstance(null, TypeEnum.bool);
     }
 
     // FIXME
@@ -941,29 +946,29 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      *
      * f0 -> <IDENTIFIER>
      */
-    public TypeInstance visit(Identifier n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(Identifier n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
-        TypeInstance ret = new TypeInstance(argu.get(n.f0.tokenImage));
+        TypeInstance ret = argu.get(n.f0.tokenImage);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
         return ret;
     }
 
-    //FIXME FIXME FIXME
+    // FIXME FIXME FIXME
     /**
      * [40]: method exists? but where is the token?
      *
      * f0 -> "this"
      */
-    public TypeInstance visit(ThisExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ThisExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
         n.f0.accept(this, argu);
-        TypeInstance ret = new TypeInstance(TypeEnum.CHECK);
+        TypeInstance ret = new TypeInstance(null, TypeEnum.CHECK);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
@@ -979,7 +984,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f3 -> Expression()
      * f4 -> "]"
      */
-    public TypeInstance visit(ArrayAllocationExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(ArrayAllocationExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -988,15 +993,15 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
         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);
+        ret = (ret.get_type() == TypeEnum.integer) ? new TypeInstance(null, TypeEnum.int_array) :
+            new TypeInstance(null, TypeEnum.ERROR);
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
         return ret;
     }
 
-    // FIXME FIXME FIXME
+    // FIXME
     /**
      * [42]:
      *
@@ -1005,7 +1010,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f2 -> "("
      * f3 -> ")"
      */
-    public TypeInstance visit(AllocationExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(AllocationExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -1025,7 +1030,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f0 -> "!"
      * f1 -> Expression()
      */
-    public TypeInstance visit(NotExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(NotExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);
 
@@ -1034,7 +1039,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
 
         this.printNode(n, argu, false, ret.get_type());
         --this.offset;
-        return (ret.get_type() == TypeEnum.bool) ? ret : new TypeInstance(TypeEnum.ERROR);
+        return (ret.get_type() == TypeEnum.bool) ? ret : new TypeInstance(null, TypeEnum.ERROR);
     }
 
     /**
@@ -1044,7 +1049,7 @@ public class TypeCheckSimp implements GJVisitor<TypeInstance,HashMap<String,Type
      * f1 -> Expression()
      * f2 -> ")"
      */
-    public TypeInstance visit(BracketExpression n, HashMap<String,TypeEnum> argu) {
+    public TypeInstance visit(BracketExpression n, HashMap<String,TypeInstance> argu) {
         ++this.offset;
         this.printNode(n, argu, true, null);