void prFieldExpList(List_field f, int d) {
    indent(d);
    say("FieldExpList("); 
    if (f!=null) {
    	for(Field i : f.list){
    		sayln("");
    		indent(d);
    		say(i.sym.toString()); sayln(" = ");
    		prExp(i.expr, d+1); sayln(",");
    	}
    }
    say(")");
  }