Parameter::Parameter(CONSTRUCT_ARGS, const string &type,
                     const string &name, int idx, bool ref,
                     ExpressionPtr defVal, int argNum)
  : Construct(CONSTRUCT_PASS), m_type(type),
    m_name(Name::fromString(CONSTRUCT_PASS, name)), m_defVal(defVal),
    m_fnName(NULL), m_idx(idx), m_kind(KindOfNull), m_argNum(argNum),
    m_ref(ref), m_nullDefault(false) {
  if (!type.empty()) {
    m_fnName = parser->peekFunc()->name().c_str();
    if (strcasecmp(type.c_str(), "array") == 0) {
      m_kind = KindOfArray;
    } else {
      m_kind = KindOfObject;
      if (strcasecmp(type.c_str(), "self") == 0 && parser->haveClass()) {
        m_type = parser->peekClass()->name();
      }
    }
    if (m_defVal) {
      ScalarExpressionPtr s = m_defVal->cast<ScalarExpression>();
      bool correct = false;
      if (s) {
        DataType dtype = s->getValue().getType();
        correct = m_nullDefault = dtype == KindOfNull;
      } else {
        ArrayExpressionPtr a = m_defVal->cast<ArrayExpression>();
        correct = a && m_kind == KindOfArray;
      }
      if (!correct) {
        if (m_kind == KindOfArray) {
          throw_fatal("Default value for parameters with array type hint can "
                      "only be an array or NULL");
        } else {
          throw_fatal("Default value for parameters with a class type hint can"
                      " only be NULL");
        }
      }
    }
  }
}