Rewrote Symbol Table to be more context aware and avoid collisions

10 files changed, 292 insertions, 150 deletions

diff --git a/J2V.java b/J2V.java
index d19b84e..16f26df 100644
--- a/J2V.java
+++ b/J2V.java
@@ -21,14 +21,18 @@ public class J2V {
             // Build the symbol table. Top-down visitor, inherits from
             // GJDepthFirst<R,A>. R=Void, A=Integer.
             SymbolTable symt = new SymbolTable();
-            root.accept(new SymTableBottomUp<Void>(), symt);
-            root.accept(new SymTableTopDown<Void>(), symt);
-
-            BoilVisitor vp = new BoilVisitor(symt);
-            root.accept(vp, null);
-
-            MinimalLogger.info("===================================================");
-            System.out.println(vp.getVapor());
+            MinimalLogger.info("Populating classes...");
+            root.accept(new SymTableClasses<Void>(), symt);
+            MinimalLogger.info("Populating methods...");
+            root.accept(new SymTableMethods<Void>(), symt);
+            MinimalLogger.info("Populating variables...");
+            root.accept(new SymTableVars<Void>(), symt);
+
+            // BoilVisitor vp = new BoilVisitor(symt);
+            // root.accept(vp, null);
+
+            // MinimalLogger.info("===================================================");
+            // System.out.println(vp.getVapor());
 
 
         }
diff --git a/st/AbstractInstance.java b/st/AbstractInstance.java
index cdeef8e..a7052a1 100644
--- a/st/AbstractInstance.java
+++ b/st/AbstractInstance.java
@@ -5,7 +5,6 @@ import java.util.ArrayList;
 public abstract class AbstractInstance {
     protected String name;                              // the literal name of the declaration
     protected TypeEnum type;                            // the type of the declaration
-    protected ClassInstance cls;                        // the surrounding class
 
     public AbstractInstance(String name, TypeEnum type) {
         this.type = type;
@@ -16,18 +15,12 @@ public abstract class AbstractInstance {
         return this.name;
     }
 
-    public boolean equals(AbstractInstance other) {
-        return this.name == other.getName() &&
-            this.type == this.type;
-    }
+    @Override public abstract boolean equals(Object other);
 
     @Override public int hashCode() {
         return this.name.hashCode();
     }
 
-    public void addClassInstance(ClassInstance cls) {
-        this.cls = cls;
-    }
 
     public String getName() {
         return this.name;
@@ -37,8 +30,4 @@ public abstract class AbstractInstance {
         return this.type;
     }
 
-    public ClassInstance getClassInstance() {
-        return this.cls;
-    }
-
 }
diff --git a/st/ClassInstance.java b/st/ClassInstance.java
index e93d3bd..8394a2c 100644
--- a/st/ClassInstance.java
+++ b/st/ClassInstance.java
@@ -13,6 +13,12 @@ public class ClassInstance extends AbstractInstance {
         this.mtds = new ArrayList<>();
     }
 
+    public boolean equals(Object other) {
+        ClassInstance o;
+        return (other instanceof ClassInstance &&
+                ((o = (ClassInstance) other).getName() == this.getName()));
+    }
+
     public ClassInstance getExtend() {
         /**
          * Returns the parent class, or
diff --git a/st/MethodInstance.java b/st/MethodInstance.java
index 6cf6ccc..c2f978b 100644
--- a/st/MethodInstance.java
+++ b/st/MethodInstance.java
@@ -5,15 +5,24 @@ import java.util.ArrayList;
 public class MethodInstance extends AbstractInstance {
     private ArrayList<TypeInstance> args;       // the list of arguments
     private ArrayList<TypeInstance> lvars;      // the list of local variables
+    protected ClassInstance par_cls;                // the surrounding class
     private TypeEnum rtrn;                      // the returned type
 
-    public MethodInstance(String name, TypeEnum rtrn) {
+    public MethodInstance(String name, TypeEnum rtrn, ClassInstance par_cls) {
         super(name, TypeEnum.method);
         this.lvars = new ArrayList<>();
         this.args = new ArrayList<>();
+        this.par_cls = par_cls;
         this.rtrn = rtrn;
     }
 
+    public boolean equals(Object other) {
+        MethodInstance o;
+        return (other instanceof MethodInstance &&
+                ((o = (MethodInstance) other).getName() == this.getName() &&
+                 o.getParentClass() == this.getParentClass()));
+    }
+
     public ArrayList<TypeInstance> getArguments() {
         return this.args;
     }
@@ -35,4 +44,12 @@ public class MethodInstance extends AbstractInstance {
         this.lvars.add(lvar);
     }
 
+    public void addParentClass(ClassInstance par_cls) {
+        this.par_cls = par_cls;
+    }
+
+    public ClassInstance getParentClass() {
+        return this.par_cls;
+    }
+
 }
diff --git a/st/SymTableClasses.java b/st/SymTableClasses.java
new file mode 100644
index 0000000..3c0b761
--- /dev/null
+++ b/st/SymTableClasses.java
@@ -0,0 +1,116 @@
+package st;
+
+import syntaxtree.*;
+import visitor.*;
+import java.util.*;
+import misc.*;
+
+/**
+ * Performs a bottom-up preliminary visit through the AST
+ * initializing all ClassInstances and placing them in the passed ST
+ */
+public class SymTableClasses<R> extends GJDepthFirst<R,SymbolTable> {
+
+    /**
+     * f0 -> "class"
+     * f1 -> Identifier()
+     * f2 -> "{"
+     * f3 -> "public"
+     * f4 -> "static"
+     * f5 -> "void"
+     * f6 -> "main"
+     * f7 -> "("
+     * f8 -> "String"
+     * f9 -> "["
+     * f10 -> "]"
+     * f11 -> Identifier()
+     * f12 -> ")"
+     * f13 -> "{"
+     * f14 -> ( VarDeclaration() )*
+     * f15 -> ( Statement() )*
+     * f16 -> "}"
+     * f17 -> "}"
+     */
+    public R visit(MainClass n, SymbolTable symt) {
+        n.f0.accept(this, symt);
+        n.f1.accept(this, symt);
+        n.f2.accept(this, symt);
+        n.f3.accept(this, symt);
+        n.f4.accept(this, symt);
+        n.f5.accept(this, symt);
+        n.f6.accept(this, symt);
+        n.f7.accept(this, symt);
+        n.f8.accept(this, symt);
+        n.f9.accept(this, symt);
+        n.f10.accept(this, symt);
+        n.f11.accept(this, symt);
+        n.f12.accept(this, symt);
+        n.f13.accept(this, symt);
+        n.f14.accept(this, symt);
+        n.f15.accept(this, symt);
+        n.f16.accept(this, symt);
+        n.f17.accept(this, symt);
+
+
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, null, null);
+        ClassInstance instance = new ClassInstance(id.getName());
+        symt.put(id, instance);
+
+        return null;
+    }
+
+    /**
+     * f0 -> "class"
+     * f1 -> Identifier()
+     * f2 -> "{"
+     * f3 -> ( VarDeclaration() )*
+     * f4 -> ( MethodDeclaration() )*
+     * f5 -> "}"
+     */
+    public R visit(ClassDeclaration n, SymbolTable symt) {
+        n.f0.accept(this, symt);
+        n.f1.accept(this, symt);
+        n.f2.accept(this, symt);
+        n.f3.accept(this, symt);
+        n.f4.accept(this, symt);
+        n.f5.accept(this, symt);
+
+
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, null, null);
+        ClassInstance instance = new ClassInstance(id.getName());
+        symt.put(id, instance);
+
+
+        return null;
+    }
+
+    /**
+     * f0 -> "class"
+     * f1 -> Identifier()
+     * f2 -> "extends"
+     * f3 -> Identifier()
+     * f4 -> "{"
+     * f5 -> ( VarDeclaration() )*
+     * f6 -> ( MethodDeclaration() )*
+     * f7 -> "}"
+     */
+    public R visit(ClassExtendsDeclaration n, SymbolTable symt) {
+        n.f0.accept(this, symt);
+        n.f1.accept(this, symt);
+        n.f2.accept(this, symt);
+        n.f3.accept(this, symt);
+        n.f4.accept(this, symt);
+        n.f5.accept(this, symt);
+        n.f6.accept(this, symt);
+        n.f7.accept(this, symt);
+
+
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, null, null);
+        ClassInstance instance = new ClassInstance(id.getName());
+        symt.put(id, instance);
+
+
+        return null;
+    }
+
+}
diff --git a/st/SymTableTopDown.java b/st/SymTableMethods.java
index 5bfd971..6dc7d68 100644
--- a/st/SymTableTopDown.java
+++ b/st/SymTableMethods.java
@@ -6,10 +6,10 @@ import java.util.*;
 import misc.*;
 
 /**
- * Performs a top-down final visit through the AST adding all local
- * methods, attributes, extension, and scoping information to the ST
+ * Performs a bottom-up preliminary visit through the AST
+ * initializing all Instances and placing them in the passed ST
  */
-public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
+public class SymTableMethods<R> extends GJDepthFirst<R,SymbolTable> {
 
     /**
      * f0 -> "class"
@@ -32,13 +32,8 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f17 -> "}"
      */
     public R visit(MainClass n, SymbolTable symt) {
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
-        symt.setActive(TypeEnum.classname, symt.getClass(id));
-        TokenKey main = new TokenKey(n.f6.tokenImage, n.f6.beginLine);
-        symt.setActive(TypeEnum.method, symt.getMethod(main));
-        symt.addMethod(main);
-
-
+        String act = n.f1.f0.tokenImage;
+        symt.setActive(TypeEnum.classname, symt.getClass(act));
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
@@ -58,7 +53,12 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
         n.f16.accept(this, symt);
         n.f17.accept(this, symt);
 
-        symt.removeActive(TypeEnum.method);
+        TokenKey id = new TokenKey(n.f6.tokenImage, (ClassInstance) symt.getActive(TypeEnum.classname), null);
+        MethodInstance main = new MethodInstance(id.getName(), TypeEnum.ERROR, (ClassInstance) symt.getActive(TypeEnum.classname));
+        symt.put(id, main);
+
+
+        symt.removeActive(TypeEnum.classname);
         return null;
     }
 
@@ -71,16 +71,17 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f5 -> "}"
      */
     public R visit(ClassDeclaration n, SymbolTable symt) {
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
-        symt.setActive(TypeEnum.classname, symt.getClass(id));
-
-
+        String act = n.f1.f0.tokenImage;
+        symt.setActive(TypeEnum.classname, symt.getClass(act));
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
         n.f3.accept(this, symt);
         n.f4.accept(this, symt);
         n.f5.accept(this, symt);
+
+
+        symt.removeActive(TypeEnum.classname);
         return null;
     }
 
@@ -95,12 +96,8 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f7 -> "}"
      */
     public R visit(ClassExtendsDeclaration n, SymbolTable symt) {
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
-        symt.setActive(TypeEnum.classname, symt.getClass(id));
-        TokenKey ext = new TokenKey(n.f3.f0.tokenImage, 0);
-        symt.setExtend(ext);
-
-
+        String act = n.f1.f0.tokenImage;
+        symt.setActive(TypeEnum.classname, symt.getClass(act));
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
@@ -109,28 +106,9 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
         n.f5.accept(this, symt);
         n.f6.accept(this, symt);
         n.f7.accept(this, symt);
-        return null;
-    }
-
-    /**
-     * f0 -> Type()
-     * f1 -> Identifier()
-     * f2 -> ";"
-     */
-    public R visit(VarDeclaration n, SymbolTable symt) {
-        String cls = (n.f0.f0.which == 3) ?
-            ((Identifier) n.f0.f0.choice).f0.tokenImage :
-            null;
-
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
-        TypeInstance me = symt.getType(id);
-        symt.addLocal(id);
-        symt.addClassInstance(me, cls);
 
 
-        n.f0.accept(this, symt);
-        n.f1.accept(this, symt);
-        n.f2.accept(this, symt);
+        symt.removeActive(TypeEnum.classname);
         return null;
     }
 
@@ -150,15 +128,6 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f12 -> "}"
      */
     public R visit(MethodDeclaration n, SymbolTable symt) {
-        ClassInstance cls = (ClassInstance) symt.getActive(TypeEnum.classname);
-
-        TokenKey id = new TokenKey(n.f2.f0.tokenImage, n.f2.f0.beginLine);
-        MethodInstance me = symt.getMethod(id);
-        symt.setActive(TypeEnum.method, me);
-        symt.addMethod(id);
-        symt.addClassInstance(me, cls.getName());
-
-
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
@@ -172,21 +141,28 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
         n.f10.accept(this, symt);
         n.f11.accept(this, symt);
         n.f12.accept(this, symt);
-        symt.removeActive(TypeEnum.method);
-        return null;
-    }
 
-    /**
-     * f0 -> Type()
-     * f1 -> Identifier()
-     */
-    public R visit(FormalParameter n, SymbolTable symt) {
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
-        symt.addParameter(id);
 
 
-        n.f0.accept(this, symt);
-        n.f1.accept(this, symt);
+        TokenKey id = new TokenKey(n.f2.f0.tokenImage, (ClassInstance) symt.getActive(TypeEnum.classname), null);
+        TypeEnum rtrn = TypeEnum.ERROR;
+        switch (n.f1.f0.which) {
+        case 0:
+            rtrn = TypeEnum.intarray; break;
+        case 1:
+            rtrn = TypeEnum.bool; break;
+        case 2:
+            rtrn = TypeEnum.integer; break;
+        case 3:
+            rtrn = TypeEnum.classname; break;
+        default:
+            MinimalLogger.severe("Unsupported case");
+        }
+
+        MethodInstance instance = new MethodInstance(id.getName(), rtrn, (ClassInstance) symt.getActive(TypeEnum.classname));
+        symt.put(id, instance);
+
+
         return null;
     }
 
diff --git a/st/SymTableBottomUp.java b/st/SymTableVars.java
index 72a4575..f356a8c 100644
--- a/st/SymTableBottomUp.java
+++ b/st/SymTableVars.java
@@ -9,7 +9,7 @@ import misc.*;
  * Performs a bottom-up preliminary visit through the AST
  * initializing all Instances and placing them in the passed ST
  */
-public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
+public class SymTableVars<R> extends GJDepthFirst<R,SymbolTable> {
 
     /**
      * f0 -> "class"
@@ -32,6 +32,10 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
      * f17 -> "}"
      */
     public R visit(MainClass n, SymbolTable symt) {
+        String id = n.f1.f0.tokenImage;
+        symt.setActive(TypeEnum.classname, symt.getClass(id));
+        id = n.f6.tokenImage;
+        symt.setActive(TypeEnum.method, symt.getMethod(id));
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
@@ -51,16 +55,9 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f16.accept(this, symt);
         n.f17.accept(this, symt);
 
-
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
-        ClassInstance instance = new ClassInstance(id.getName());
-        symt.put(id, instance);
-
-        id = new TokenKey(n.f6.tokenImage, n.f6.beginLine);
-        MethodInstance main = new MethodInstance(id.getName(), TypeEnum.ERROR);
-        symt.put(id, main);
-
-
+        symt.addMethod(id);
+        symt.removeActive(TypeEnum.method);
+        symt.removeActive(TypeEnum.classname);
         return null;
     }
 
@@ -73,6 +70,8 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
      * f5 -> "}"
      */
     public R visit(ClassDeclaration n, SymbolTable symt) {
+        String id = n.f1.f0.tokenImage;
+        symt.setActive(TypeEnum.classname, symt.getClass(id));
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
@@ -80,12 +79,7 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f4.accept(this, symt);
         n.f5.accept(this, symt);
 
-
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
-        ClassInstance instance = new ClassInstance(id.getName());
-        symt.put(id, instance);
-
-
+        symt.removeActive(TypeEnum.classname);
         return null;
     }
 
@@ -100,6 +94,8 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
      * f7 -> "}"
      */
     public R visit(ClassExtendsDeclaration n, SymbolTable symt) {
+        String id = n.f1.f0.tokenImage;
+        symt.setActive(TypeEnum.classname, symt.getClass(id));
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
@@ -109,12 +105,7 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f6.accept(this, symt);
         n.f7.accept(this, symt);
 
-
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
-        ClassInstance instance = new ClassInstance(id.getName());
-        symt.put(id, instance);
-
-
+        symt.removeActive(TypeEnum.classname);
         return null;
     }
 
@@ -127,8 +118,9 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
-
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage,
+                                   (ClassInstance) symt.getActive(TypeEnum.classname),
+                                   (MethodInstance) symt.getActive(TypeEnum.method));
         TypeEnum rtrn = TypeEnum.ERROR;
         switch (n.f0.f0.which) {
         case 0:
@@ -143,9 +135,10 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
             MinimalLogger.severe("Unsupported case");
         }
 
-        TypeInstance instance = new TypeInstance(id.getName(), rtrn);
+        TypeInstance instance = new TypeInstance(id.getName(), rtrn, (MethodInstance) symt.getActive(TypeEnum.method),
+                                                 (ClassInstance) symt.getActive(TypeEnum.classname));
         symt.put(id, instance);
-
+        symt.addLocal(id.getName());
 
         return null;
     }
@@ -166,6 +159,9 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
      * f12 -> "}"
      */
     public R visit(MethodDeclaration n, SymbolTable symt) {
+        String id = n.f2.f0.tokenImage;
+        symt.setActive(TypeEnum.method, symt.getMethod(id));
+        symt.addMethod(id);
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
@@ -181,26 +177,7 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f12.accept(this, symt);
 
 
-
-        TokenKey id = new TokenKey(n.f2.f0.tokenImage, n.f2.f0.beginLine);
-        TypeEnum rtrn = TypeEnum.ERROR;
-        switch (n.f1.f0.which) {
-        case 0:
-            rtrn = TypeEnum.intarray; break;
-        case 1:
-            rtrn = TypeEnum.bool; break;
-        case 2:
-            rtrn = TypeEnum.integer; break;
-        case 3:
-            rtrn = TypeEnum.classname; break;
-        default:
-            MinimalLogger.severe("Unsupported case");
-        }
-
-        MethodInstance instance = new MethodInstance(id.getName(), rtrn);
-        symt.put(id, instance);
-
-
+        symt.removeActive(TypeEnum.method);
         return null;
     }
 
@@ -211,9 +188,10 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
     public R visit(FormalParameter n, SymbolTable symt) {
         n.f0.accept(this, symt);
         n.f1.accept(this, symt);
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage,
+                                   (ClassInstance) symt.getActive(TypeEnum.classname),
+                                   (MethodInstance) symt.getActive(TypeEnum.method));
 
-
-        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
         TypeEnum rtrn = TypeEnum.ERROR;
         switch (n.f0.f0.which) {
         case 0:
@@ -228,8 +206,10 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
             MinimalLogger.severe("Unsupported case");
         }
 
-        TypeInstance instance = new TypeInstance(id.getName(), rtrn);
+        TypeInstance instance = new TypeInstance(id.getName(), rtrn, (MethodInstance) symt.getActive(TypeEnum.method),
+                                                 (ClassInstance) symt.getActive(TypeEnum.classname));
         symt.put(id, instance);
+        symt.addParameter(id.getName());
 
 
         return null;
diff --git a/st/SymbolTable.java b/st/SymbolTable.java
index dcc1f5b..a8a6dcf 100644
--- a/st/SymbolTable.java
+++ b/st/SymbolTable.java
@@ -42,7 +42,7 @@ public class SymbolTable {
     /**
      * Methods intended to be used during the second pass
      */
-    public void setExtend(TokenKey arg) {
+    public void setExtend(String arg) {
         ClassInstance cls = (ClassInstance) this.active.get(TypeEnum.classname);
         ClassInstance ext = this.getClass(arg);
 
@@ -64,7 +64,7 @@ public class SymbolTable {
         }
     }
 
-    public void addLocal(TokenKey lvar) {
+    public void addLocal(String lvar) {
         TypeInstance var = this.getType(lvar);
         AbstractInstance par;
         if (this.active.get(TypeEnum.method) != null) { // we are in a method
@@ -81,7 +81,7 @@ public class SymbolTable {
                                          par.getName(), par.getType()));
     }
 
-    public void addMethod(TokenKey mtd) {
+    public void addMethod(String mtd) {
         ClassInstance cls = (ClassInstance) this.active.get(TypeEnum.classname);
         MethodInstance lmtd = this.getMethod(mtd);
 
@@ -91,7 +91,7 @@ public class SymbolTable {
                                          lmtd.getName(), cls.getName()));
     }
 
-    public void addParameter(TokenKey arg) {
+    public void addParameter(String arg) {
         MethodInstance mtd = (MethodInstance) this.active.get(TypeEnum.method);
         TypeInstance para = this.getType(arg);
 
@@ -99,11 +99,14 @@ public class SymbolTable {
 
         MinimalLogger.info(String.format("Added %s as a parameter of %s",
                                          para.getName(), mtd.getName()));
+        MinimalLogger.info(String.format("Added %s as a localvar of %s",
+                                         para.getName(), mtd.getName()));
+
     }
 
-    public void addClassInstance(AbstractInstance t, String c) {
+    public void addClassInstance(TypeInstance t, String c) {
         ClassInstance cls = (c != null) ?
-            this.getClass(new TokenKey(c, 0)) :
+            this.getClass(c) :
             null;
 
         t.addClassInstance(cls);
@@ -128,7 +131,10 @@ public class SymbolTable {
         this.active.remove(type);
     }
 
-    public TypeInstance getType(TokenKey id) {
+    public TypeInstance getType(String name) {
+        TokenKey id = new TokenKey(name,
+                                   (ClassInstance) this.getActive(TypeEnum.classname),
+                                   (MethodInstance) this.getActive(TypeEnum.method));
         AbstractInstance symbol;
         TypeInstance ret = ((symbol = this.symt.get(id)) !=
                             null && symbol instanceof TypeInstance) ?
@@ -139,7 +145,10 @@ public class SymbolTable {
         return ret;
     }
 
-    public MethodInstance getMethod(TokenKey id) {
+    public MethodInstance getMethod(String name) {
+        TokenKey id = new TokenKey(name,
+                                   (ClassInstance) this.getActive(TypeEnum.classname),
+                                   null);
         AbstractInstance symbol;
         MethodInstance ret = ((symbol = this.symt.get(id)) !=
                               null && symbol instanceof MethodInstance) ?
@@ -150,7 +159,10 @@ public class SymbolTable {
         return ret;
     }
 
-    public ClassInstance getClass(TokenKey id) {
+    public ClassInstance getClass(String name) {
+        TokenKey id = new TokenKey(name,
+                                   null,
+                                   null);
         AbstractInstance symbol;
         ClassInstance ret =  ((symbol = this.symt.get(id)) !=
                               null && symbol instanceof ClassInstance) ?
diff --git a/st/TokenKey.java b/st/TokenKey.java
index 2319917..54086c5 100644
--- a/st/TokenKey.java
+++ b/st/TokenKey.java
@@ -8,18 +8,20 @@ package st;
 public class TokenKey {
 
     private String name;
-    private int beginLine;
+    private AbstractInstance cls; // null for classes
+    private AbstractInstance mtd; // null for classes, methods
 
-    public TokenKey(String name, int beginLine) {
-        // classes CANNOT collide, so CALLEES ARE EXPECTED TO USE ZERO!
+    public TokenKey(String name, AbstractInstance cls, AbstractInstance mtd) {
         this.name = name;
-        this.beginLine = beginLine;
+        this.cls = cls;
+        this.mtd = mtd;
     }
 
     @Override public String toString() {
-        return String.format("%s (%d)",
+        return String.format("%s (%s,%s)",
                              this.name,
-                             this.beginLine);
+                             this.mtd,
+                             this.cls);
     }
 
 
@@ -28,7 +30,8 @@ public class TokenKey {
         TokenKey o;
         if (other instanceof TokenKey &&
             (o = (TokenKey) other).name == this.name &&
-            o.beginLine == this.beginLine) {
+            o.cls == this.cls &&
+            o.mtd == this.mtd) {
             ret = true;
         }
         return ret;
diff --git a/st/TypeInstance.java b/st/TypeInstance.java
index 88b73f3..e43c5b3 100644
--- a/st/TypeInstance.java
+++ b/st/TypeInstance.java
@@ -2,8 +2,23 @@ package st;
 
 public class TypeInstance extends AbstractInstance {
 
-    public TypeInstance(String name, TypeEnum type) {
+    protected ClassInstance par_cls;                        // the surrounding class
+    protected MethodInstance par_mtd;                       // the surrounding method
+    protected ClassInstance cls;                            // the class instance
+
+
+    public TypeInstance(String name, TypeEnum type, MethodInstance par_mtd, ClassInstance par_cls) {
         super(name, type);
+        this.par_cls = par_cls;
+        this.par_mtd = par_mtd;
+    }
+
+    @Override public boolean equals(Object other) {
+        TypeInstance o;
+        return (other instanceof TypeInstance &&
+                ((o = (TypeInstance) other).getName() == this.getName() &&
+                 o.getParentClass() == this.getParentClass() &&
+                 o.getParentMethod() == this.getParentMethod()));
     }
 
     public int getSize() {
@@ -30,4 +45,28 @@ public class TypeInstance extends AbstractInstance {
         return type != TypeEnum.ERROR;
     }
 
+    public void addClassInstance(ClassInstance cls) {
+        this.cls = cls;
+    }
+
+    public ClassInstance getClassInstance() {
+        return this.cls;
+    }
+
+    public void addParentClass(ClassInstance par_cls) {
+        this.par_cls = par_cls;
+    }
+
+    public ClassInstance getParentClass() {
+        return this.par_cls;
+    }
+
+    public void addParentMethod(MethodInstance par_mtd) {
+        this.par_mtd = par_mtd;
+    }
+
+    public MethodInstance getParentMethod() {
+        return this.par_mtd;
+    }
+
 }