parser.hpp

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        {
            handle_.pop ();
            assert (handle_.top ()._type == token::EXPRESSION);
            // perform join
            sequence (node_ptr_vector_, tree_node_stack_);
            token_stack_.push (token::SUB);
        }
    }

    static void repeat (token_stack &handle_, token_stack &token_stack_)
    {
        assert (handle_.top ()._type == token::REPEAT &&
            handle_.size () >= 1 && handle_.size () <= 3);

        if (handle_.size () == 1)
        {
            token_stack_.push (token::EXPRESSION);
        }
        else
        {
            handle_.pop ();
            assert (handle_.top ()._type == token::DUP);
            token_stack_.push (token::REPEAT);
        }
    }

    static void charset (token_stack &handle_, token_stack &token_stack_,
        node_ptr_vector &node_ptr_vector_, tree_node_stack &tree_node_stack_)
    {
        assert (handle_.top ()._type == token::CHARSET &&
            handle_.size () == 1);
        // store charset
        node_ptr_vector_->push_back (0);

        const size_t id_ = handle_.top ()._id;

        node_ptr_vector_->back () = new leaf_node (id_, true);
        tree_node_stack_.push (node_ptr_vector_->back ());
        token_stack_.push (token::REPEAT);
    }

    static void macro (token_stack &handle_, token_stack &token_stack_,
        const macro_map &macromap_, node_ptr_vector &node_ptr_vector_,
        tree_node_stack &tree_node_stack_)
    {
        token &top_ = handle_.top ();

        assert (top_._type == token::MACRO && handle_.size () == 1);

        typename macro_map::const_iterator iter_ =
            macromap_.find (top_._macro);

        if (iter_ == macromap_.end ())
        {
            const CharT *name_ = top_._macro;
            std::basic_stringstream<CharT> ss_;
            std::ostringstream os_;

            os_ << "Unknown MACRO name '";

            while (*name_)
            {
                os_ << ss_.narrow (*name_++, ' ');
            }

            os_ << "'.";
            throw runtime_error (os_.str ());
        }

        tree_node_stack_.push (iter_->second->copy (node_ptr_vector_));
        token_stack_.push (token::REPEAT);
    }

    static void openparen (token_stack &handle_, token_stack &token_stack_)
    {
        assert (handle_.top ()._type == token::OPENPAREN &&
            handle_.size () == 3);
        handle_.pop ();
        assert (handle_.top ()._type == token::REGEX);
        handle_.pop ();
        assert (handle_.top ()._type == token::CLOSEPAREN);
        token_stack_.push (token::REPEAT);
    }

    static void perform_or (node_ptr_vector &node_ptr_vector_,
        tree_node_stack &tree_node_stack_)
    {
        // perform or
        node *rhs_ = tree_node_stack_.top ();

        tree_node_stack_.pop ();

        node *lhs_ = tree_node_stack_.top ();

        node_ptr_vector_->push_back (0);
        node_ptr_vector_->back () = new selection_node (lhs_, rhs_);
        tree_node_stack_.top () = node_ptr_vector_->back ();
    }

    static void sequence (node_ptr_vector &node_ptr_vector_,
        tree_node_stack &tree_node_stack_)
    {
        node *rhs_ = tree_node_stack_.top ();

        tree_node_stack_.pop ();

        node *lhs_ = tree_node_stack_.top ();

        node_ptr_vector_->push_back (0);
        node_ptr_vector_->back () = new sequence_node (lhs_, rhs_);
        tree_node_stack_.top () = node_ptr_vector_->back ();
    }

    static void optional (const bool greedy_,
        node_ptr_vector &node_ptr_vector_, tree_node_stack &tree_node_stack_)
    {
        // perform ?
        node *lhs_ = tree_node_stack_.top ();
        // You don't know if lhs_ is a leaf_node, so get firstpos.
        node::node_vector &firstpos_ = lhs_->firstpos();

        for (node::node_vector::iterator iter_ = firstpos_.begin (),
            end_ = firstpos_.end (); iter_ != end_; ++iter_)
        {
            // These are leaf_nodes!
            (*iter_)->greedy (greedy_);
        }

        node_ptr_vector_->push_back (0);

        node *rhs_ = new leaf_node (null_token, greedy_);

        node_ptr_vector_->back () = rhs_;
        node_ptr_vector_->push_back (0);
        node_ptr_vector_->back () = new selection_node (lhs_, rhs_);
        tree_node_stack_.top () = node_ptr_vector_->back ();
    }

    static void zero_or_more (const bool greedy_,
        node_ptr_vector &node_ptr_vector_, tree_node_stack &tree_node_stack_)
    {
        // perform *
        node *ptr_ = tree_node_stack_.top ();

        node_ptr_vector_->push_back (0);
        node_ptr_vector_->back () = new iteration_node (ptr_, greedy_);
        tree_node_stack_.top () = node_ptr_vector_->back ();
    }

    static void one_or_more (const bool greedy_,
        node_ptr_vector &node_ptr_vector_, tree_node_stack &tree_node_stack_)
    {
        // perform +
        node *lhs_ = tree_node_stack_.top ();
        node *copy_ = lhs_->copy (node_ptr_vector_);

        node_ptr_vector_->push_back (0);

        node *rhs_ = new iteration_node (copy_, greedy_);

        node_ptr_vector_->back () = rhs_;
        node_ptr_vector_->push_back (0);
        node_ptr_vector_->back () = new sequence_node (lhs_, rhs_);
        tree_node_stack_.top () = node_ptr_vector_->back ();
    }

    static void repeatn (const bool greedy_, const token &token_,
        node_ptr_vector &node_ptr_vector_, tree_node_stack &tree_node_stack_)
    {
        // perform {n[,[m]]}
        // Semantic checks have already been performed.
        // {0,}  = *
        // {0,1} = ?
        // {1,}  = +
        // therefore we do not check for these cases.
        if (!(token_._min == 1 && !token_._comma))
        {
            const std::size_t top_ = token_._min > 0 ?
                token_._min : token_._max;

            if (token_._min == 0)
            {
                optional (greedy_, node_ptr_vector_, tree_node_stack_);
            }

            node *prev_ = tree_node_stack_.top ()->copy (node_ptr_vector_);
            node *curr_ = 0;

            for (std::size_t i_ = 2; i_ < top_; ++i_)
            {
                node *temp_ = prev_->copy (node_ptr_vector_);

                curr_ = temp_;
                tree_node_stack_.push (0);
                tree_node_stack_.top () = prev_;
                sequence (node_ptr_vector_, tree_node_stack_);
                prev_ = curr_;
            }

            if (token_._comma && token_._min > 0)
            {
                if (token_._min > 1)
                {
                    node *temp_ = prev_->copy (node_ptr_vector_);

                    curr_ = temp_;
                    tree_node_stack_.push (0);
                    tree_node_stack_.top () = prev_;
                    sequence (node_ptr_vector_, tree_node_stack_);
                    prev_ = curr_;
                }

                if (token_._comma && token_._max)
                {
                    tree_node_stack_.push (0);
                    tree_node_stack_.top () = prev_;
                    optional (greedy_, node_ptr_vector_, tree_node_stack_);

                    node *temp_ = tree_node_stack_.top ();

                    tree_node_stack_.pop ();
                    prev_ = temp_;

                    const std::size_t count_ = token_._max - token_._min;

                    for (std::size_t i_ = 1; i_ < count_; ++i_)
                    {
                        node *temp_ = prev_->copy (node_ptr_vector_);

                        curr_ = temp_;
                        tree_node_stack_.push (0);
                        tree_node_stack_.top () = prev_;
                        sequence (node_ptr_vector_, tree_node_stack_);
                        prev_ = curr_;
                    }
                }
                else
                {
                    tree_node_stack_.push (0);
                    tree_node_stack_.top () = prev_;
                    zero_or_more (greedy_, node_ptr_vector_, tree_node_stack_);

                    node *temp_ = tree_node_stack_.top ();

                    prev_ = temp_;
                    tree_node_stack_.pop ();
                }
            }

            tree_node_stack_.push (0);
            tree_node_stack_.top () = prev_;
            sequence (node_ptr_vector_, tree_node_stack_);
        }
    }
};
}
}
}

#endif