107  }

   107    @Override

   108    String toQueryString() {

   109         // Parentheses are only added if needed to disambiguate.

   110         return parens(exp1) + " and " + parens(exp2);

   111    }

   112 

   113    // Add parens if needed to disambiguate an expression such as

   114    // Query.and(Query.or(a, b), c).  We need to return

   115    // (a or b) and c

   116    // in such a case, because

   117    // a or b and c

   118    // would mean

   119    // a or (b and c)

   120    private static String parens(QueryExp exp) {

   121        String s = Query.toString(exp);

   122        if (exp instanceof OrQueryExp)

   123            return "(" + s + ")";

   124        else

   125            return s;

   126    }

   127 

   128 }