Rewrote SymbolTable to add uniqueness to stored tokens

4 files changed, 127 insertions, 66 deletions

diff --git a/st/SymTableBottomUp.java b/st/SymTableBottomUp.java
index b0772fc..72a4575 100644
--- a/st/SymTableBottomUp.java
+++ b/st/SymTableBottomUp.java
@@ -52,14 +52,12 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f17.accept(this, symt);
 
 
-        String id = n.f1.f0.tokenImage;
-        ClassInstance instance = new ClassInstance(id);
-        MinimalLogger.info("Inserting " + id + " => " + instance.getType());
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
+        ClassInstance instance = new ClassInstance(id.getName());
         symt.put(id, instance);
 
-        id = "main";
-        MethodInstance main = new MethodInstance(id, TypeEnum.ERROR);
-        MinimalLogger.info("Inserting " + id + " => " + main.getType());
+        id = new TokenKey(n.f6.tokenImage, n.f6.beginLine);
+        MethodInstance main = new MethodInstance(id.getName(), TypeEnum.ERROR);
         symt.put(id, main);
 
 
@@ -83,9 +81,8 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f5.accept(this, symt);
 
 
-        String id = n.f1.f0.tokenImage;
-        ClassInstance instance = new ClassInstance(id);
-        MinimalLogger.info("Inserting " + id + " => " + instance.getType());
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
+        ClassInstance instance = new ClassInstance(id.getName());
         symt.put(id, instance);
 
 
@@ -113,9 +110,8 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f7.accept(this, symt);
 
 
-        String id = n.f1.f0.tokenImage;
-        ClassInstance instance = new ClassInstance(id);
-        MinimalLogger.info("Inserting " + id + " => " + instance.getType());
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
+        ClassInstance instance = new ClassInstance(id.getName());
         symt.put(id, instance);
 
 
@@ -132,7 +128,7 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f1.accept(this, symt);
         n.f2.accept(this, symt);
 
-        String id = n.f1.f0.tokenImage;
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
         TypeEnum rtrn = TypeEnum.ERROR;
         switch (n.f0.f0.which) {
         case 0:
@@ -147,8 +143,7 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
             MinimalLogger.severe("Unsupported case");
         }
 
-        TypeInstance instance = new TypeInstance(id, rtrn);
-	MinimalLogger.info("Inserting " + id + " => " + instance.getType());
+        TypeInstance instance = new TypeInstance(id.getName(), rtrn);
         symt.put(id, instance);
 
 
@@ -186,7 +181,8 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f12.accept(this, symt);
 
 
-        String id = n.f2.f0.tokenImage;
+
+        TokenKey id = new TokenKey(n.f2.f0.tokenImage, n.f2.f0.beginLine);
         TypeEnum rtrn = TypeEnum.ERROR;
         switch (n.f1.f0.which) {
         case 0:
@@ -201,8 +197,7 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
             MinimalLogger.severe("Unsupported case");
         }
 
-        MethodInstance instance = new MethodInstance(id, rtrn);
-        MinimalLogger.info("Inserting " + id + " => " + instance.getType());
+        MethodInstance instance = new MethodInstance(id.getName(), rtrn);
         symt.put(id, instance);
 
 
@@ -218,7 +213,7 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
         n.f1.accept(this, symt);
 
 
-        String id = n.f1.f0.tokenImage;
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
         TypeEnum rtrn = TypeEnum.ERROR;
         switch (n.f0.f0.which) {
         case 0:
@@ -233,8 +228,7 @@ public class SymTableBottomUp<R> extends GJDepthFirst<R,SymbolTable> {
             MinimalLogger.severe("Unsupported case");
         }
 
-        TypeInstance instance = new TypeInstance(id, rtrn);
-        MinimalLogger.info("Inserting " + id + " => " + instance.getType());
+        TypeInstance instance = new TypeInstance(id.getName(), rtrn);
         symt.put(id, instance);
 
 
diff --git a/st/SymTableTopDown.java b/st/SymTableTopDown.java
index 566752e..5bfd971 100644
--- a/st/SymTableTopDown.java
+++ b/st/SymTableTopDown.java
@@ -32,10 +32,11 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f17 -> "}"
      */
     public R visit(MainClass n, SymbolTable symt) {
-        String id = n.f1.f0.tokenImage;
-        symt.setActive(TypeEnum.classname, id);
-        symt.setActive(TypeEnum.method, "main");
-        symt.addMethod("main");
+        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);
 
 
         n.f0.accept(this, symt);
@@ -70,8 +71,8 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f5 -> "}"
      */
     public R visit(ClassDeclaration n, SymbolTable symt) {
-        String id = n.f1.f0.tokenImage;
-        symt.setActive(TypeEnum.classname, id);
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
+        symt.setActive(TypeEnum.classname, symt.getClass(id));
 
 
         n.f0.accept(this, symt);
@@ -94,9 +95,10 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f7 -> "}"
      */
     public R visit(ClassExtendsDeclaration n, SymbolTable symt) {
-        String id = n.f1.f0.tokenImage;
-        symt.setActive(TypeEnum.classname, id);
-        symt.setExtend(n.f3.f0.tokenImage);
+        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);
 
 
         n.f0.accept(this, symt);
@@ -120,7 +122,7 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
             ((Identifier) n.f0.f0.choice).f0.tokenImage :
             null;
 
-        String id = n.f1.f0.tokenImage;
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
         TypeInstance me = symt.getType(id);
         symt.addLocal(id);
         symt.addClassInstance(me, cls);
@@ -148,13 +150,13 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f12 -> "}"
      */
     public R visit(MethodDeclaration n, SymbolTable symt) {
-        String cls = symt.getActive(TypeEnum.classname);
+        ClassInstance cls = (ClassInstance) symt.getActive(TypeEnum.classname);
 
-        String id = n.f2.f0.tokenImage;
+        TokenKey id = new TokenKey(n.f2.f0.tokenImage, n.f2.f0.beginLine);
         MethodInstance me = symt.getMethod(id);
-        symt.setActive(TypeEnum.method, id);
+        symt.setActive(TypeEnum.method, me);
         symt.addMethod(id);
-        symt.addClassInstance(me, cls);
+        symt.addClassInstance(me, cls.getName());
 
 
         n.f0.accept(this, symt);
@@ -179,7 +181,7 @@ public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {
      * f1 -> Identifier()
      */
     public R visit(FormalParameter n, SymbolTable symt) {
-        String id = n.f1.f0.tokenImage;
+        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
         symt.addParameter(id);
 
 
diff --git a/st/SymbolTable.java b/st/SymbolTable.java
index 77b8a93..e6c4738 100644
--- a/st/SymbolTable.java
+++ b/st/SymbolTable.java
@@ -9,18 +9,19 @@ import misc.*;
  * of each symbol consistent.
  */
 public class SymbolTable {
-    private HashMap<String,AbstractInstance> symt;  // the mapping of ids to Instances
-    private HashMap<TypeEnum,String> active;        // the current scope of the visitor (class, method)
+    private HashMap<TokenKey,AbstractInstance> symt;    // the mapping of ids to Instances
+    private HashMap<TypeEnum,AbstractInstance> active;  // the current scope of the visitor (class, method)
 
     public SymbolTable() {
+        MinimalLogger.info("Creating a new SymbolTable...");
         this.symt = new HashMap<>();
         this.active = new HashMap<>();
     }
 
     @Override public String toString() {
         StringBuilder mapAsString = new StringBuilder("{");
-        for (String key : this.symt.keySet()) {
-            mapAsString.append(key + ":" + this.symt.get(key).getType() + ", ");
+        for (TokenKey key : this.symt.keySet()) {
+            mapAsString.append(key.toString() + ":" + this.symt.get(key).getType() + ", ");
         }
         mapAsString.delete(mapAsString.length()-2, mapAsString.length()).append("}");
         return mapAsString.toString();
@@ -30,7 +31,10 @@ public class SymbolTable {
     /**
      * Methods intended to be used during the first pass
      */
-    public void put(String id, AbstractInstance symbol) {
+    public void put(TokenKey id, AbstractInstance symbol) {
+        MinimalLogger.info(String.format("Inserting %s -> %s",
+                                         id,
+                                         symbol.getType()));
         this.symt.put(id, symbol);
     }
 
@@ -38,71 +42,87 @@ public class SymbolTable {
     /**
      * Methods intended to be used during the second pass
      */
-    public void setExtend(String arg) {
-        String str = this.active.get(TypeEnum.classname);
-        ClassInstance cls = this.getClass(str);
+    public void setExtend(TokenKey arg) {
+        ClassInstance cls = (ClassInstance) this.active.get(TypeEnum.classname);
         ClassInstance ext = this.getClass(arg);
 
+        MinimalLogger.info(String.format("%s found to extend %s",
+                                         cls.getName(),
+                                         ext.getName()));
         cls.setExtend(ext);
         // for (TypeInstance : ext.attrs) //FIXME add the extended classes' stuff
         //     cls.add
     }
 
-    public void addLocal(String lvar) {
+    public void addLocal(TokenKey lvar) {
         TypeInstance var = this.getType(lvar);
+        AbstractInstance par;
         if (this.active.get(TypeEnum.method) != null) { // we are in a method
-            String str = this.active.get(TypeEnum.method);
-            MethodInstance mtd = this.getMethod(str);
-            mtd.addLocal(var);
-            var.setScope(mtd);
+            MethodInstance par1 = (MethodInstance) this.active.get(TypeEnum.method);
+            par1.addLocal(var);
+            var.setScope(par1);
+            par = par1;
         } else {
-            String str = this.active.get(TypeEnum.classname);
-            ClassInstance cls = this.getClass(str);
-            cls.addLocal(var);
-            var.setScope(cls);
+            ClassInstance par1 = (ClassInstance) this.active.get(TypeEnum.classname);
+            par1.addLocal(var);
+            var.setScope(par1);
+            par = par1;
         }
+        MinimalLogger.info(String.format("Added %s (%s) as a local var of %s (%s)",
+                                         var.getName(), var.getType(),
+                                         par.getName(), par.getType()));
     }
 
-    public void addMethod(String mtd) {
-        String str = this.active.get(TypeEnum.classname);
-        ClassInstance cls = this.getClass(str);
+    public void addMethod(TokenKey mtd) {
+        ClassInstance cls = (ClassInstance) this.active.get(TypeEnum.classname);
         MethodInstance lmtd = this.getMethod(mtd);
 
         lmtd.setScope(cls);
         cls.addMethod(lmtd);
+
+        MinimalLogger.info(String.format("Added %s as a method of %s",
+                                         lmtd.getName(), cls.getName()));
     }
 
-    public void addParameter(String arg) {
-        String str = this.active.get(TypeEnum.method);
-        MethodInstance mtd = this.getMethod(str);
+    public void addParameter(TokenKey arg) {
+        MethodInstance mtd = (MethodInstance) this.active.get(TypeEnum.method);
         TypeInstance para = this.getType(arg);
 
         para.setScope(mtd);
         mtd.addArgument(para); // also adds to local vars
+
+        MinimalLogger.info(String.format("Added %s as a parameter of %s",
+                                         para.getName(), mtd.getName()));
     }
 
     public void addClassInstance(AbstractInstance t, String c) {
         ClassInstance cls = (c != null) ?
-            this.getClass(c) :
+            this.getClass(new TokenKey(c, 0)) :
             null;
 
         t.addClassInstance(cls);
     }
 
-
     /**
      * Methods to safely retrieve differentiable types
      * in `typecheck', `vaporize' libraries
      */
-    public void setActive(TypeEnum type, String id) {
+    public void setActive(TypeEnum type, AbstractInstance id) {
+        MinimalLogger.info(String.format("%s is now the active %s.",
+                                         id.getName(),
+                                         type));
         this.active.put(type, id);
     }
 
     public void removeActive(TypeEnum type) {
+        AbstractInstance id = this.getActive(type);
+        MinimalLogger.info(String.format("%s is no longer the active %s.",
+                                         id.getName(),
+                                         type));
         this.active.remove(type);
     }
 
-    public TypeInstance getType(String id) {
+    public TypeInstance getType(TokenKey id) {
         AbstractInstance symbol;
         TypeInstance ret = ((symbol = this.symt.get(id)) !=
                             null && symbol instanceof TypeInstance) ?
@@ -113,7 +133,7 @@ public class SymbolTable {
         return ret;
     }
 
-    public MethodInstance getMethod(String id) {
+    public MethodInstance getMethod(TokenKey id) {
         AbstractInstance symbol;
         MethodInstance ret = ((symbol = this.symt.get(id)) !=
                               null && symbol instanceof MethodInstance) ?
@@ -124,7 +144,7 @@ public class SymbolTable {
         return ret;
     }
 
-    public ClassInstance getClass(String id) {
+    public ClassInstance getClass(TokenKey id) {
         AbstractInstance symbol;
         ClassInstance ret =  ((symbol = this.symt.get(id)) !=
                               null && symbol instanceof ClassInstance) ?
@@ -135,7 +155,7 @@ public class SymbolTable {
         return ret;
     }
 
-    public String getActive(TypeEnum type) {
+    public AbstractInstance getActive(TypeEnum type) {
         return this.active.get(type);
     }
 
diff --git a/st/TokenKey.java b/st/TokenKey.java
new file mode 100644
index 0000000..2319917
--- /dev/null
+++ b/st/TokenKey.java
@@ -0,0 +1,45 @@
+package st;
+
+/**
+ * This class is a data structure used to distinguish tokens in
+ * a given program. Tokens are considered unique if their "beginLine"
+ * and name are different.
+ */
+public class TokenKey {
+
+    private String name;
+    private int beginLine;
+
+    public TokenKey(String name, int beginLine) {
+        // classes CANNOT collide, so CALLEES ARE EXPECTED TO USE ZERO!
+        this.name = name;
+        this.beginLine = beginLine;
+    }
+
+    @Override public String toString() {
+        return String.format("%s (%d)",
+                             this.name,
+                             this.beginLine);
+    }
+
+
+    @Override public boolean equals(Object other) {
+        boolean ret = false;
+        TokenKey o;
+        if (other instanceof TokenKey &&
+            (o = (TokenKey) other).name == this.name &&
+            o.beginLine == this.beginLine) {
+            ret = true;
+        }
+        return ret;
+    }
+
+    @Override public int hashCode() {
+        return this.name.hashCode();
+    }
+
+    public String getName() {
+        return this.name;
+    }
+
+}