code-cleanup, refactoring, corrected multiple u...

code-cleanup, refactoring, corrected multiple use of the same symbol

4 files changed, 342 insertions, 387 deletions

diff --git a/sources/scalac/transformer/matching/Autom2Scala.java b/sources/scalac/transformer/matching/Autom2Scala.java
index ba2539ed09..19785e840e 100644
--- a/sources/scalac/transformer/matching/Autom2Scala.java
+++ b/sources/scalac/transformer/matching/Autom2Scala.java
@@ -19,6 +19,7 @@ import ch.epfl.lamp.util.Position;
 
 public class Autom2Scala  {
 
+      static final Name HASNEXT = Name.fromString("hasnext");
       static final Name CURRENT_ELEM = Name.fromString("cur");
 
       final int FAIL = -1;
@@ -126,6 +127,14 @@ public class Autom2Scala  {
                                           funSym,//clazzOwner,
                                           0)
                   .setType( elementType );
+
+            this.hasnSym = new TermSymbol( /*Kinds.VAL, */
+                                          pos,
+                                          HASNEXT,
+                                          funSym,//clazzOwner,
+                                          0)
+                  .setType( defs.BOOLEAN_TYPE );
+
       }
 
 
@@ -149,12 +158,20 @@ public class Autom2Scala  {
       public Tree theDefDef;
 
       Symbol curSym;
-
-      Tree loadCurrentElem() {
-            return cf.Block( Position.NOPOS, new Tree[] {
-		cf.gen.ValDef( 0,
-			       this.curSym,
-			       cf._next( _iter() )) }, Type.NoType );
+      Symbol hasnSym;
+
+      Tree loadCurrentElem( Tree body ) {
+	  return cf.Block( Position.NOPOS, new Tree[] {
+	      cf.gen.ValDef( 0,
+			     this.hasnSym,
+			     cf._hasNext( _iter() ) ),
+	      cf.gen.ValDef( 0,
+			     this.curSym,
+			     cf.If( _ref( hasnSym ),//cf._hasNext( _iter() ),
+				    cf._next( _iter() ),
+				    cf.ignoreValue( curSym.type() ))),
+	      body },
+	      body.type() );
       }
 
       Tree currentElem() {
@@ -238,7 +255,9 @@ public class Autom2Scala  {
             for( int i = dfa.nstates-2; i >= 0; i-- ) {
                   body = code_state( i, body );
             }
-            return body;
+
+
+            return loadCurrentElem( body );
 
       }
 
@@ -305,6 +324,17 @@ public class Autom2Scala  {
             return gen.mkIntLit(Position.NOPOS, FAIL );
       }
 
+    /*
+    Tree ifInputHasNext() {
+	return cf.If( cf._hasNext( _iter() ),
+		      cf.Block( stateBody.pos,
+				new Tree[] {
+				    loadCurrentElem(),
+				    stateBody},
+				stateBody.type()) );
+    }
+    */
+
       Tree wrapStateBody0( Tree stateBody,
                            Tree elseBody,
                            int i ) {
@@ -313,78 +343,79 @@ public class Autom2Scala  {
                           elseBody );
       }
 
-      // val cur := iter.cur()
+      // `val cur := iter.next()'
 
-      Tree wrapStateBody( Tree stateBody,
-                          Tree elseBody,
-                          Tree runFinished, int i ) {
-            stateBody = cf.If( cf._not_hasNext( _iter() ),
-                               runFinished,
-                               cf.Block( stateBody.pos,
-                                         new Tree[] {
-                                               loadCurrentElem(),
-                                               stateBody},
-                                         stateBody.type()) );
+    Tree wrapStateBody( Tree stateBody,
+			Tree elseBody,
+			Tree runFinished, int i ) {
+	stateBody = cf.If( cf.Negate( _ref( hasnSym )),//cf._not_hasNext( _iter() ),
+			   runFinished,
+			   stateBody);/*
+			   cf.Block( stateBody.pos,
+				     new Tree[] {
+					 loadCurrentElem(),
+					 stateBody},
+					 stateBody.type()) );*/
 
-            return wrapStateBody0( stateBody , elseBody, i );
-      }
+	return wrapStateBody0( stateBody , elseBody, i );
+    }
 
-      /** return code for state i of the dfa
-       */
-      Tree code_state( int i, Tree elseBody ) {
+    /** return code for state i of the dfa
+     */
+    Tree code_state( int i, Tree elseBody ) {
 
-            Tree runFinished; // holds result of the run
-            int  finalSwRes;
+	Tree runFinished; // holds result of the run
+	int  finalSwRes;
 
-            runFinished = run_finished( i );
+	runFinished = run_finished( i );
 
 
-            if( dfa.isSink( i ) )  // state won't change anymore (binding?)
-                  return cf.If( cf.Equals( _state(), gen.mkIntLit(Position.NOPOS, i )),
-                              runFinished,
-                              elseBody );
+	if( dfa.isSink( i ) )  // state won't change anymore (binding?)
+	    return cf.If( cf.Equals( _state(), gen.mkIntLit(Position.NOPOS, i )),
+			  runFinished,
+			  elseBody );
 
 
-            Tree stateBody ; // action(delta) for one particular label/test
+	Tree stateBody ; // action(delta) for one particular label/test
 
-            // default action (fail if there is none)
+	// default action (fail if there is none)
 
-            stateBody = code_delta( i, Label.DefaultLabel);
+	stateBody = code_delta( i, Label.DefaultLabel);
 
-            /*
-            if( stateBody == null )
-                  stateBody = code_fail();
-            */
+	/*
+	  if( stateBody == null )
+	  stateBody = code_fail();
+	*/
 
-            // transitions of state i
+	// transitions of state i
 
-            HashMap trans = ((HashMap[])dfa.deltaq)[ i ];
+	HashMap trans = ((HashMap[])dfa.deltaq)[ i ];
 
-            for( Iterator labs = dfa.labels.iterator(); labs.hasNext() ; ) {
-                  Object label = labs.next();
-                  Integer next = (Integer) trans.get( label );
+	for( Iterator labs = dfa.labels.iterator(); labs.hasNext() ; ) {
+	    Object label = labs.next();
+	    Integer next = (Integer) trans.get( label );
 
 
-                  Tree action = code_delta( i, (Label) label );
+	    Tree action = code_delta( i, (Label) label );
 
-                  if( action != null ) {
+	    if( action != null ) {
 
-                        stateBody = cf.If( currentMatches((Label) label ),
-                                         action,
-                                         stateBody);
-                  }
-            }
-            return wrapStateBody( stateBody,
-                                  elseBody,
-                                  runFinished,
-                                  i );
-      }
+		stateBody = cf.If( currentMatches((Label) label ),
+				   action,
+				   stateBody);
+	    }
+	}
+	return wrapStateBody( stateBody,
+			      elseBody,
+			       runFinished,
+			      i );
+    }
 
-      /** code to reference a variable
-       */
-      Tree _ref( Symbol sym ) {
-            return gen.Ident( pos, sym );
-      }
+    /** code to reference a variable
+     */
+    Tree _ref( Symbol sym ) {
+	return gen.Ident( pos, sym );
+    }
 
 
 }
diff --git a/sources/scalac/transformer/matching/CodeFactory.java b/sources/scalac/transformer/matching/CodeFactory.java
index 033621c810..662e3c8c31 100644
--- a/sources/scalac/transformer/matching/CodeFactory.java
+++ b/sources/scalac/transformer/matching/CodeFactory.java
@@ -432,8 +432,8 @@ class CodeFactory extends PatternTool {
         return make.Block(pos, ts).setType(tpe);
     }
 
-    /* // unused
-       protected Tree Negate(Tree tree) {
+     // unused
+       public Tree Negate(Tree tree) {
        switch (tree) {
        case Literal(Object value):
        return gen.mkBooleanLit(tree.pos, !((Boolean)value).booleanValue());
@@ -443,7 +443,7 @@ class CodeFactory extends PatternTool {
        gen.Select(tree, NOT_N),
        Tree.EMPTY_ARRAY).setType(defs.BOOLEAN_TYPE);
        }
-    */
+
     protected Tree And(Tree left, Tree right) {
         switch (left) {
 	case Literal(Object value):
diff --git a/sources/scalac/transformer/matching/LeftTracerInScala.java b/sources/scalac/transformer/matching/LeftTracerInScala.java
index f9e02cf9d7..85e1e002eb 100644
--- a/sources/scalac/transformer/matching/LeftTracerInScala.java
+++ b/sources/scalac/transformer/matching/LeftTracerInScala.java
@@ -13,7 +13,7 @@ import java.util.* ;
 
 import ch.epfl.lamp.util.Position;
 
-public class LeftTracerInScala extends Autom2Scala {
+public class LeftTracerInScala extends TracerInScala {
 
       Tree selector;
 
@@ -34,337 +34,298 @@ public class LeftTracerInScala extends Autom2Scala {
                                 Type elementType,
                                 Matcher m,
                                 CodeFactory cf ) {
-            // ignore clazzOwner!
-            super( dfa, elementType, m.owner, cf );
-            this._m = m;
-            this.selector = m.selector;
-            helpMap = new HashMap();
-            helpVarDefs = new Vector();
 
-      }
-
-
-      // SAME AS IN RightTracerInScala,
-      // todo create common abstract superclass Tracer/TransducerInScala,
-      // move WordAutom down.
-      HashMap helpMap ;
-      Vector  helpVarDefs;
-
-      Symbol makeHelpVar( Symbol realVar ) {
-	  Symbol helpVar = new TermSymbol( //Kinds.VAR,
-                                             pos,
-                                             cf.fresh.newName( realVar.name
-                                                               .toString() ),
-                                             owner,
-                                             0)
-                  .setType( cf.SeqListType( elementType ) ) ;
+	  super( dfa, elementType, m.owner, cf );
+	  this._m = m;
+	  this.selector = m.selector;
+	  //helpMap = new HashMap(); moved up
+	  helpVarDefs = new Vector();
 
-            helpMap.put( realVar, helpVar );
-
-            Tree varDef = gen.ValDef(helpVar, cf.newSeqNil( elementType ));
-            //((ValDef) varDef).kind = Kinds.VAR;
-            helpVarDefs.add( varDef );
-            return helpVar;
       }
 
-      Symbol makeHelpVarSEQ( Tree pat ) {
-            String  helpName = String.valueOf( pat.hashCode() ); //wicked, in'it ?
-            Symbol helpVar =
-		new TermSymbol( /*Kinds.VAR, */pos,
-                                  cf.fresh.newName(Name.fromString( helpName )),
-                                  owner,
-                                  0)
-                  .setType( cf.SeqListType( pat.type() )) ;
-
-            ValDef varDef = (ValDef) gen.ValDef( helpVar,
-                                                 cf.ignoreValue( cf.SeqListType( pat.type() )));
-            //varDef.kind = Kinds.VAR;
-            helpVarDefs.add( varDef );
-            return helpVar;
-      }
 
-      // SAME AS RIGHT
-      Tree refHelpVar( Symbol realVar ) {
-            Symbol hv = (Symbol)helpMap.get( realVar );
-            assert hv != null : realVar;
-            return gen.Ident( Position.NOPOS, hv );
-      }
-
-      // SAME AS RIGHT
-      Tree assignToHelpVar( Symbol realVar, Tree rhs ) {
-            Tree hv = refHelpVar( realVar );
-            return gen.Assign( hv, rhs );
-      }
-
-      void handleVars( Vector freeVars ) {
-            for(Iterator it = freeVars.iterator(); it.hasNext(); ) {
-                  makeHelpVar( (Symbol) it.next() );
-            }
+    // move WordAutom down.
+
+    Vector  helpVarDefs;
+
+    Symbol makeHelpVar( Symbol realVar ) {
+	Symbol helpVar = new TermSymbol( pos,
+					 cf.fresh.newName( realVar.name
+							   .toString() ),
+					 owner,
+					 0)
+	    .setType( cf.SeqListType( elementType ) ) ;
+
+	helpMap.put( realVar, helpVar );
+
+	Tree varDef = gen.ValDef(helpVar, cf.newSeqNil( elementType ));
+	// set mutable flag of symbol helpVar ??
+	helpVarDefs.add( varDef );
+	return helpVar;
+    }
+
+    Symbol makeHelpVarSEQ( Tree pat ) {
+	String  helpName = String.valueOf( pat.hashCode() ); //wicked, in'it ?
+	Symbol helpVar =
+	    new TermSymbol( pos,
+			    cf.fresh.newName(Name.fromString( helpName )),
+			    owner,
+			    0)
+	    .setType( cf.SeqListType( pat.type() )) ;
+
+	ValDef varDef = (ValDef) gen.ValDef( helpVar,
+					     cf.ignoreValue( cf.SeqListType( pat.type() )));
+	helpVarDefs.add( varDef );
+	return helpVar;
+    }
+
+    void handleVars( Vector freeVars ) {
+	for(Iterator it = freeVars.iterator(); it.hasNext(); ) {
+	    makeHelpVar( (Symbol) it.next() );
+	}
+    }
+
+    /** returns a Tree whose type is boolean.
+     *  now we care about free vars
+     */
+    /*
+      Tree handleBody( HashMap helpMap ) {
+      Tree res[] = new Tree[ helpMap.keySet().size() + 1 ];
+      int j = 0;
+      for( Iterator it = helpMap.keySet().iterator(); it.hasNext(); ) {
+      Symbol vsym = (Symbol) it.next();
+      Symbol hv   = (Symbol) helpMap.get( vsym );
+      hv.type( cf.SeqListType( elementType ) ) ;
+      Tree refv   = gen.Ident(Position.NOPOS, vsym);
+      Tree refhv  = gen.Ident(Position.NOPOS, hv);
+      res[ j++ ] = gen.Assign( refhv, refv );
       }
 
-      Tree bindVar(Symbol realVar) {
-            Tree hv = refHelpVar( realVar );
-            System.out.println("realVar.name "+realVar.name+" type:"+realVar.type());
-            if( realVar.type().isSameAs( elementType ))
-                  return gen.ValDef( realVar, cf.SeqList_head( hv ));
-            else
-                  return gen.ValDef( realVar, hv);
+      res[ j ] = super.handleBody( freeVars ); // just `true'
 
+      return cf.Block(Position.NOPOS, res, res[j].type() );
       }
+    */
+    protected void initializeSyms() {
+	funSymName = "leftTracer";
 
+	nestedMap = new HashMap();
 
-      /** returns a Tree whose type is boolean.
-       *  now we care about free vars
-       */
-      /*
-      Tree handleBody( HashMap helpMap ) {
-            Tree res[] = new Tree[ helpMap.keySet().size() + 1 ];
-            int j = 0;
-            for( Iterator it = helpMap.keySet().iterator(); it.hasNext(); ) {
-                  Symbol vsym = (Symbol) it.next();
-                  Symbol hv   = (Symbol) helpMap.get( vsym );
-                  hv.type( cf.SeqListType( elementType ) ) ;
-                  Tree refv   = gen.Ident(Position.NOPOS, vsym);
-                  Tree refhv  = gen.Ident(Position.NOPOS, hv);
-                  res[ j++ ] = gen.Assign( refhv, refv );
-            }
-
-            res[ j ] = super.handleBody( freeVars ); // just `true'
-
-            return cf.Block(Position.NOPOS, res, res[j].type() );
-      }
-*/
-      protected void initializeSyms() {
-            funSymName = "leftTracer";
+	super.initializeSyms();
 
-            nestedMap = new HashMap();
+	this.accumSym = newParam("accum")                    // accumulator
+	    .setType( _accumType( elementType ));
 
-            super.initializeSyms();
+	this.funSym
+	    .setType( new Type.MethodType( new Symbol[] {
+		accumSym, iterSym, stateSym},
+					   _accumType( elementType )));
 
-            this.accumSym = newParam("accum")                    // accumulator
-                  .setType( _accumType( elementType ));
+	// 2 do: rename switchresultsym to something else...
 
-            this.funSym
-                  .setType( new Type.MethodType( new Symbol[] {
-                        accumSym, iterSym, stateSym},
-                                              _accumType( elementType )));
+	this.resultSym = new TermSymbol( //Kinds.VAR,
+					pos,
+					cf.fresh.newName("trace"),
+					owner,
+					0 )
+	    .setType( _accumType( elementType ) ) ;
 
-            // 2 do: rename switchresultsym to something else...
+    }
 
-            this.resultSym = new TermSymbol( //Kinds.VAR,
-                                                   pos,
-                                                   cf.fresh.newName("trace"),
-                                                   owner,
-                                                   0 )
-                  .setType( _accumType( elementType ) ) ;
+    // should throw an exception here really, e.g. MatchError
+    Tree code_fail() {
+	return gen.Ident( accumSym.pos, accumSym );
 
-      }
+    }
 
-      /** do the translation
-      public void translate() {
-            initializeSyms();
-            Tree tb = code_body();
-            theDefDef = gen.DefDef( this.funSym,
-                                    tb );
-      }
-       */
 
-      // should throw an exception here really, e.g. MatchError
-      Tree code_fail() {
 
-            return gen.Ident( accumSym.pos, accumSym );
+    /** returns translation of transition with label from i.
+     *  returns null if there is no such transition(no translation needed)
+     */
+    Tree code_delta( int i, Label label ) {
+	Integer target = dfa.delta( i, label );
+	/*
+	  System.out.println("LeftTracer:calling dfa.delta("+i+","+label+")");
+	  System.out.println("result: "+target);
+	*/
+	if( target == null )
+	    return null;
 
-      }
+	// (optimization) that one is a dead state (does not make sense for tracer)
+	/*
+	  if( target == dfa.nstates - 1 )
+	  return code_fail();
+	*/
+	Tree newAcc = cf.newSeqTraceCons(new Integer(i),
+					 currentElem(),
+					 _ref( accumSym ));
 
+	return callFun( new Tree[] { newAcc , _iter(), cf.Int( target )} );
+    }
 
 
-      /** returns translation of transition with label from i.
-       *  returns null if there is no such transition(no translation needed)
-       */
-      Tree code_delta( int i, Label label ) {
-            Integer target = dfa.delta( i, label );
-            /*
-            System.out.println("LeftTracer:calling dfa.delta("+i+","+label+")");
-            System.out.println("result: "+target);
-            */
-            if( target == null )
-                  return null;
-
-            // (optimization) that one is a dead state (does not make sense for tracer)
-            /*
-              if( target == dfa.nstates - 1 )
-            return code_fail();
-            */
-            Tree newAcc = cf.newSeqTraceCons(new Integer(i),
-                                             currentElem(),
-                                             _ref( accumSym ));
-
-            return callFun( new Tree[] { newAcc , _iter(), cf.Int( target )} );
-      }
+    /** return code for state i of the dfa SAME AS IN SUPER, ONLY SINK IS GONE
+     */
+    Tree code_state( int i, Tree elseBody ) {
 
+	Tree runFinished; // holds result of the run
+	int  finalSwRes;
 
-      /** return code for state i of the dfa SAME AS IN SUPER, ONLY SINK IS GONE
-       */
-      Tree code_state( int i, Tree elseBody ) {
+	runFinished = run_finished( i );
 
-            Tree runFinished; // holds result of the run
-            int  finalSwRes;
+	Tree stateBody ; // action(delta) for one particular label/test
 
-            runFinished = run_finished( i );
+	// default action (fail if there is none)
 
-            Tree stateBody ; // action(delta) for one particular label/test
+	stateBody = code_delta( i, Label.DefaultLabel);
 
-            // default action (fail if there is none)
+	if( stateBody == null )
+	    stateBody = code_fail();
+	// transitions of state i
 
-            stateBody = code_delta( i, Label.DefaultLabel);
+	HashMap trans = ((HashMap[])dfa.deltaq)[ i ];
 
-            if( stateBody == null )
-                  stateBody = code_fail();
-            // transitions of state i
+	for( Iterator labs = ((HashMap)dfa.deltaq( i )).keySet().iterator();
+	     labs.hasNext() ; ) {
+	    Object label = labs.next();
+	    Integer next = (Integer) trans.get( label );
 
-            HashMap trans = ((HashMap[])dfa.deltaq)[ i ];
 
-            for( Iterator labs = ((HashMap)dfa.deltaq( i )).keySet().iterator();
-                 labs.hasNext() ; ) {
-                  Object label = labs.next();
-                  Integer next = (Integer) trans.get( label );
+	    Tree action = code_delta( i, (Label) label );
 
+	    if( action != null ) {
 
-                  Tree action = code_delta( i, (Label) label );
+		stateBody = cf.If( _cur_eq( _iter(), (Label) label ),
+				   action,
+				   stateBody);
+	    }
+	}
 
-                  if( action != null ) {
+	return wrapStateBody( stateBody,
+			      elseBody,
+			      runFinished,
+			      i );
 
-                        stateBody = cf.If( _cur_eq( _iter(), (Label) label ),
-                                         action,
-                                         stateBody);
-                  }
-            }
+    }
 
-            return wrapStateBody( stateBody,
-                                  elseBody,
-                                  runFinished,
-                                  i );
+    Tree[] getTrace() {
 
-      }
+	initializeSyms();
+	Tree tb = code_body();
+	theDefDef = gen.DefDef( this.funSym,
+				tb );
 
-      Tree[] getTrace() {
+	Vector v = new Vector();
 
-            initializeSyms();
-            Tree tb = code_body();
-            theDefDef = gen.DefDef( this.funSym,
-                                    tb );
+	v.addAll( helpVarDefs );
 
-            Vector v = new Vector();
+	//
+	// `def leftTracer(...) = ...'                 the function definition
+	v.add( theDefDef );
 
-            v.addAll( helpVarDefs );
+	Tree emptyAcc    = cf._seqTraceNil( elementType );
 
-            //
-            // `def leftTracer(...) = ...'                 the function definition
-            v.add( theDefDef );
+	// the valdef is needed, because passing emptyAcc as a parameter
+	//   results in a ClassCastException at runtime (?!)
 
-            Tree emptyAcc    = cf._seqTraceNil( elementType );
+	Symbol emptyAccSym = new TermSymbol( pos,
+					     cf.fresh.newName("acc"),
+					     owner,
+					     0 )
+	    .setType( _accumType( elementType ) ) ;
 
-            // the valdef is needed, because passing emptyAcc as a parameter
-            //   results in a ClassCastException at runtime (?!)
+	// `val acc = SeqNil[ elementType ]'                 init accumulator
+	v.add( gen.ValDef( pos, emptyAccSym, emptyAcc) );
 
-            Symbol emptyAccSym = new TermSymbol( //Kinds.VAR,
-                                                 pos,
-                                                 cf.fresh.newName("acc"),
-                                                 owner,
-                                                 0 )
-                  .setType( _accumType( elementType ) ) ;
+	Tree run = callFun( new Tree[] {
+	    gen.Ident( pos, emptyAccSym ),
+	    cf.newIterator( selector, selector.type() ),
+	    cf.Int( 0 )  });
 
-            // `val acc = SeqNil[ elementType ]'                 init accumulator
-            v.add( gen.ValDef( pos, emptyAccSym, emptyAcc) );
+	run = gen.ValDef( Position.NOPOS, resultSym, run );
 
-            Tree run = callFun( new Tree[] {
-                  gen.Ident( pos, emptyAccSym ),
-                  cf.newIterator( selector, selector.type() ),
-                  cf.Int( 0 )  });
+	v.add( run );
 
-            run = gen.ValDef( Position.NOPOS, resultSym, run );
+	// vars...
+	for( Iterator it = helpMap.keySet().iterator(); it.hasNext(); ) {
+	    v.add( bindVar( (Symbol) it.next()) );
+	}
 
-            v.add( run );
+	/* IF YOU NEED DEBUG OUTPUT AT RUNTIME
+	   v.add( cf.debugPrintRuntime( "the trace is" ) );
+	   v.add( cf.debugPrintRuntime( gen.Ident( pos, resultSym ) ) );
+	   v.add( cf.debugPrintNewlineRuntime( "" ) );
+	*/
 
-            // vars...
-            for( Iterator it = helpMap.keySet().iterator(); it.hasNext(); ) {
-                  v.add( bindVar( (Symbol) it.next()) );
-            }
+	Tree res[] = new Tree[ v.size() ];
+	int j = 0;
+	for( Iterator it = v.iterator(); it.hasNext(); )
+	    res[ j++ ] = (Tree) it.next();
 
-            /* IF YOU NEED DEBUG OUTPUT AT RUNTIME
-            v.add( cf.debugPrintRuntime( "the trace is" ) );
-            v.add( cf.debugPrintRuntime( gen.Ident( pos, resultSym ) ) );
-            v.add( cf.debugPrintNewlineRuntime( "" ) );
-            */
+	_m.varMap = nestedMap;
 
-            Tree res[] = new Tree[ v.size() ];
-            int j = 0;
-            for( Iterator it = v.iterator(); it.hasNext(); )
-                  res[ j++ ] = (Tree) it.next();
+	return res;
 
-            _m.varMap = nestedMap;
+    }
 
-            return res;
+    public HashMap nestedMap;
 
-      }
+    // calling the AlgebraicMatcher here
+    Tree _cur_match( Tree pat ) {
+	//System.out.println("calling algebraic matcher on type:"+pat.type);
 
-      public HashMap nestedMap;
-
-      // calling the AlgebraicMatcher here
-      Tree _cur_match( Tree pat ) {
-            //System.out.println("calling algebraic matcher on type:"+pat.type);
-
-            Matcher m = new Matcher( funSym,
-                                     currentElem(),
-                                     defs.BOOLEAN_TYPE );
-
-            if( CollectVariableTraverser.containsBinding( pat )) {
-                  switch( pat ) {
-                  case Sequence(Tree[] pats):
-                        //System.out.println("ouch! v Left");
-                        Symbol hv = makeHelpVarSEQ( pat );
-                        nestedMap.put( pat, hv );
-                        Tree stm  = gen.Assign( gen.Ident(0, hv), currentElem() );
-                        m.stms = new Tree[2];
-                        m.stms[0] = stm;
-                        m.stms[1] = gen.mkBooleanLit(Position.NOPOS, true);
-                        return cf.Block( 0, m.stms, m.stms[1].type() );
-                  }
-            }
-
-            HashMap helpMap = FreshVariableTraverser.getVars( pat, owner, cf.fresh );
-            //System.out.println("varMap: "+helpMap );
-
-            m.varMap = helpMap;
-
-            //replaceVars( pat );
-
-            am.construct( m, new CaseDef[] {
-                  (CaseDef) cf.make.CaseDef( pat.pos,
-                                             pat,
-                                             Tree.Empty,
-                                             handleBody( helpMap )),
-                        (CaseDef) cf.make.CaseDef( pat.pos,
-                                                   cf.make.Ident(pat.pos, Names.WILDCARD)
-                                                   //.setSymbol( Symbol.NONE ) FIXED
-                                                   .setType(pat.type()),
-                                                   Tree.Empty,
-                                                   gen.mkBooleanLit(Position.NOPOS, false)) },
-			  false
-                          );
-            Tree res = am.toTree().setType( defs.BOOLEAN_TYPE );
-            //System.out.println("freeVars: "+freeVars);
-
-            return res;
-      }
+	Matcher m = new Matcher( funSym,
+				 currentElem(),
+				 defs.BOOLEAN_TYPE );
 
+	if( CollectVariableTraverser.containsBinding( pat )) {
+	    switch( pat ) {
+	    case Sequence(Tree[] pats):
+		//System.out.println("ouch! v Left");
+		Symbol hv = makeHelpVarSEQ( pat );
+		nestedMap.put( pat, hv );
+		Tree stm  = gen.Assign( gen.Ident(0, hv), currentElem() );
+		m.stms = new Tree[2];
+		m.stms[0] = stm;
+		m.stms[1] = gen.mkBooleanLit(Position.NOPOS, true);
+		return cf.Block( 0, m.stms, m.stms[1].type() );
+	    }
+	}
 
-      /** return the accumulator + last state
-       */
-      Tree run_finished( int state ) {
-            return cf.newSeqTraceCons(new Integer( state ),
-                                      cf.ignoreValue( elementType ),
-                                      _ref( accumSym ));
-      }
+	HashMap helpMap = FreshVariableTraverser.getVars( pat, owner, cf.fresh );
+	//System.out.println("varMap: "+helpMap );
+
+	m.varMap = helpMap;
+
+	//replaceVars( pat );
+
+	am.construct( m, new CaseDef[] {
+	    (CaseDef) cf.make.CaseDef( pat.pos,
+				       pat,
+				       Tree.Empty,
+				       handleBody( helpMap )),
+	    (CaseDef) cf.make.CaseDef( pat.pos,
+				       cf.make.Ident(pat.pos, Names.WILDCARD)
+				       //DON'T .setSymbol( Symbol.NONE ) !
+				       .setType(pat.type()),
+				       Tree.Empty,
+				       gen.mkBooleanLit(Position.NOPOS, false)) },
+		      false
+		      );
+	Tree res = am.toTree().setType( defs.BOOLEAN_TYPE );
+	//System.out.println("freeVars: "+freeVars);
+
+	return res;
+    }
+
+
+    /** return the accumulator + last state
+     */
+    Tree run_finished( int state ) {
+	return cf.newSeqTraceCons(new Integer( state ),
+				  cf.ignoreValue( elementType ),
+				  _ref( accumSym ));
+    }
 
 }
diff --git a/sources/scalac/transformer/matching/RightTracerInScala.java b/sources/scalac/transformer/matching/RightTracerInScala.java
index 3ae2854860..1ed0b69864 100644
--- a/sources/scalac/transformer/matching/RightTracerInScala.java
+++ b/sources/scalac/transformer/matching/RightTracerInScala.java
@@ -17,7 +17,7 @@ import scalac.util.Names ;
 
 import ch.epfl.lamp.util.Position;
 
-public class RightTracerInScala extends Autom2Scala  {
+public class RightTracerInScala extends TracerInScala  {
 
       //Scope  scp;
       //Symbol vars[];
@@ -27,6 +27,15 @@ public class RightTracerInScala extends Autom2Scala  {
 
       Matcher _m;
 
+      //      Symbol funSym;
+
+      Symbol elemSym;
+      Symbol targetSym;
+
+      HashMap helpMap2 ;
+      Vector  helpVarDefs;
+
+
       /** translate right tracer to code
        * @param dfa determinized left tracer
        * @param left nondeterm. left tracer
@@ -43,7 +52,6 @@ public class RightTracerInScala extends Autom2Scala  {
             super( dfa, elementType, m.owner, cf );
             this._m = m;
 
-
             Vector seqVars = new Vector();
 
             for( int j = 0; j < left.nstates; j++ ) {
@@ -60,7 +68,6 @@ public class RightTracerInScala extends Autom2Scala  {
             this.seqVars = seqVars;
             this.allVars = CollectVariableTraverser.collectVars( pat );
 
-            helpMap = new HashMap();
             helpMap2 = new HashMap();
             helpVarDefs = new Vector();
 
@@ -78,15 +85,6 @@ public class RightTracerInScala extends Autom2Scala  {
             initializeSyms();
       }
 
-      //      Symbol funSym;
-
-      Symbol elemSym;
-      Symbol targetSym;
-
-      HashMap helpMap ;
-      HashMap helpMap2 ;
-      Vector  helpVarDefs;
-
       void makeHelpVar( Symbol realVar ) {
             makeHelpVar( realVar, false );
       }
@@ -121,12 +119,6 @@ public class RightTracerInScala extends Autom2Scala  {
 
       }
 
-      Tree refHelpVar( Symbol realVar ) {
-            Symbol hv = (Symbol)helpMap.get( realVar );
-            assert hv != null : realVar;
-            return gen.Ident(Position.NOPOS, hv);
-      }
-
       Tree prependToHelpVar( Symbol realVar, Tree elem ) {
             Tree hv = refHelpVar( realVar );
             return gen.Assign( hv, cf.newSeqCons( elem, hv ));
@@ -139,44 +131,29 @@ public class RightTracerInScala extends Autom2Scala  {
             */
       }
 
-      Tree bindVar(Symbol realVar) {
-            Tree hv = refHelpVar( realVar );
-            //System.out.println("binding realVar.name "+realVar.name+" type:"+realVar.type()+" to smth");
-            realVar.setOwner( owner );
-            if( realVar.type().isSameAs( elementType ))
-                  return gen.ValDef( realVar, cf.SeqList_head( hv ));
-            else
-                  return gen.ValDef( realVar, hv);
-
-      }
-
       protected void initializeSyms() {
 
             this.funSym = newFunSym( "binder" );
 
-            this.iterSym = new TermSymbol( //Kinds.VAL,
-                                           pos,
+            this.iterSym = new TermSymbol( pos,
                                            cf.fresh.newName("iter"),
                                            funSym,
                                            0)
                   .setType( cf.SeqTraceType( elementType ));
 
-            this.stateSym = new TermSymbol( //Kinds.VAL,
-                                            pos,
+            this.stateSym = new TermSymbol( pos,
                                             cf.fresh.newName("q"),
                                             funSym,
                                             0 )
                   .setType( defs.INT_TYPE ) ;
 
-            this.elemSym = new TermSymbol( //Kinds.VAL,
-                                           pos,
+            this.elemSym = new TermSymbol( pos,
                                            cf.fresh.newName("elem"),
                                            funSym,
                                            0)
                   .setType( elementType ) ;
 
-            this.targetSym = new TermSymbol( //Kinds.VAL,
-                                             pos,
+            this.targetSym = new TermSymbol( pos,
                                              cf.fresh.newName("trgt"),
                                              funSym,
                                              0)
@@ -340,9 +317,6 @@ public class RightTracerInScala extends Autom2Scala  {
                   this.helpMap2.put( key, helpMap.get( key ));
             }
 
-	    // find this weird ? pattern matcher expects var. symbol for _ pattern FIXME ?!! CANNOT BE TRUE
-	    //Symbol obfuscvble = new TermSymbol(0, Name.fromString("ga$ga$ga$"), _m.owner, 0).setType( pat.type() );
-
             am.construct( m, new CaseDef[] {
                   (CaseDef) cf.make.CaseDef( pat.pos,
                                              pat,
@@ -350,7 +324,7 @@ public class RightTracerInScala extends Autom2Scala  {
                                              handleBody( helpMap2 )),
                         (CaseDef) cf.make.CaseDef( pat.pos,
                                                    cf.make.Ident(pat.pos, Names.WILDCARD)
-                                                   //.setSymbol( Symbol.NONE ) FIXED
+                                                   //DON'T .setSymbol( Symbol.NONE ) !!FIXED
 						   .setType( pat.type() ),
                                                    Tree.Empty,
                                                    gen.mkBooleanLit( pat.pos, false )) },
@@ -405,11 +379,7 @@ public class RightTracerInScala extends Autom2Scala  {
             for( Iterator it = vars.iterator(); it.hasNext(); ) {
                   Symbol var = (Symbol) it.next();
 
-                  /*Tree field = gen.Select( gen.Ident( pos, accumSym ),
-                                           var.name ).setSymbol( var );
-                  */
-                  //Tree field = gen.Ident( pos, var );
-                  Tree rhs = gen.Ident( pos, elemSym ); //cf._cur( _iter() );
+                  Tree rhs = gen.Ident( pos, elemSym );
 
                   stms[ j++ ] = prependToHelpVar( var , rhs);
             }
@@ -437,7 +407,6 @@ public class RightTracerInScala extends Autom2Scala  {
             v.add( gen.DefDef( this.funSym, code_body() )  );
             v.add( callFun( new Tree[] {  trace, cf.Int( 0 )  }  )  );
 
-
             /*
             for(Iterator it = helpMap.keySet().iterator(); it.hasNext(); ) {
                   // DEBUG
@@ -464,16 +433,10 @@ public class RightTracerInScala extends Autom2Scala  {
       }
 
       /** return the accumulator. (same as in LeftTracerInScala)
+       *  todo: move tree generation of Unit somewhere else
        */
       Tree run_finished( int state ) {
-            //return gen.Ident( accumSym.pos, accumSym );
 	  return gen.Block(0, Tree.EMPTY_ARRAY).setType( defs.UNIT_TYPE );
-	      /* gen.Ident(0, defs.NULL); */
-	  /*gen.New( pos, defs.SCALA_TYPE, defs.NULL, //UNIT_CLASS,
-                            Type.EMPTY_ARRAY,
-                            Tree.EMPTY_ARRAY);                             */
-
-
       }
 
       Tree current() {