import edu.neu.ccs.demeterf.*;
import edu.neu.ccs.demeter.Ident;

// to compute the supertype of a class look
// underlying traversal visits entire class graph
// inefficient because no traversal control is used
// combine methods send the supertype up the class graph

public class SuperType extends ID{
    String look;
    SuperType(String s){ look = s; }

    // passing down the containing object
    Object update(Object o, Object prev){ return o; }

    // use apply for leafs
    String apply(TypeName i){ return (""+i).equals(look)?""+i:""; }

    // s for subtypes, c for enclosing ClassDef
    // structural assumption: enclosing class of Abstract is ClassDef
    // if subtraversal found a match, pass up name of class definition
    String combine(Abstract a, String s, ClassDef c){
        return (s.equals(""))?s:c.name.toString();
    }

    // n for name, d for decl, only interested in decl
    String combine(ClassDef c, Object n, String d){ return d; }      
    String combine(ConsList c, String f, String r){ return r.equals("")?f:r; }

    // used for Concrete: does not contribute to superclass computation
    String combine(Object c){ return ""; }
}