package tarau.jinni;
/**
  Used in implementing uniform replacement of
  variables with new constants. useful for printing
  out with nicer variable names.

  @see Var
  @see Clause
*/
class VarNumberer extends SystemObject {
   HashDict dict;
   int ctr;

   VarNumberer() {
     dict = new HashDict();
     ctr = 0;
   }

   Term action(Term place) {
     place=place.ref();
     //IO.trace(">>action: "+place);
     if(place instanceof Var) {
        Const root=(Const)dict.get(place);
        if(null==root) {
          root=new PseudoVar(ctr++);
          dict.put(place,root);
        }
        place = root;
     }
     //IO.trace("<<action: "+place);
     return place;
   }
}