*/
public String getConstantString(Value v) {
if (v==null)
throw new RuntimeException("null value");
if (v instanceof StringConstant) {
StringConstant sc = (StringConstant)v;
return unescapeStringConstant(sc);
} else if (v instanceof Local) {
StringConstant sc = stringConstants.getFlowBefore(currentUnit).get(v);
if (sc != null) {
return unescapeStringConstant(sc);
}
} else if (v instanceof NullConstant) {
return null;