while ((exp = s.indexOf("${", pos)) >= 0) {
ret.append(s.substring(pos, exp));
pos = s.indexOf("}", exp);
while ((exp = s.indexOf("${", pos)) >= 0) {
ret.append(s.substring(pos, exp));
pos = s.indexOf("}", exp);
pos = s.indexOf("}", exp);
ret.append("return (");
ret.append(s.substring(exp + 2, pos));
pos = s.indexOf("}", exp);
ret.append("return (");
ret.append(s.substring(exp + 2, pos));