branch_iter.hh

// Copyright (C) 2007, 2008, 2009 EPITA Research and Development Laboratory (LRDE)
//
// This file is part of Olena.
//
// Olena is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation, version 2 of the License.
//
// Olena is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Olena.  If not, see <http://www.gnu.org/licenses/>.
//
// As a special exception, you may use this file as part of a free
// software project without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
// file, or you compile this file and link it with other files to produce
// an executable, this file does not by itself cause the resulting
// executable to be covered by the GNU General Public License.  This
// exception does not however invalidate any other reasons why the
// executable file might be covered by the GNU General Public License.

#ifndef MLN_UTIL_BRANCH_ITER_HH
# define MLN_UTIL_BRANCH_ITER_HH

# include <stack>
# include <mln/util/tree.hh>

namespace mln
{

  namespace util
  {

    template <typename T>
    class branch_iter
    {
    public:
      branch_iter(branch<T> branch);

      operator util::tree_node<T>&() const;
      util::tree_node<T>& operator *();

      bool is_valid() const;

      void invalidate();

      void start();

      void next();

      unsigned deepness() const;
    private:
      util::branch<T> branch_;

      typedef typename std::vector< util::tree_node<T>* >::iterator child_iter;
      typedef std::pair<child_iter, child_iter> iter_pair;
      std::stack< iter_pair > s_;

      util::tree_node<T>* n_;
    };


# ifndef MLN_INCLUDE_ONLY


    template <typename T>
    inline
    branch_iter<T>::branch_iter(branch<T> branch)
      : branch_(branch)
    {
      invalidate();
    }

    template <typename T>
    inline
    branch_iter<T>::operator util::tree_node<T>&() const
    {
      mln_assertion(n_);
      return *n_;
    }

    template <typename T>
    inline
    util::tree_node<T>&
    branch_iter<T>::operator*()
    {
      mln_assertion(n_);
      return *n_;
    }

    template <typename T>
    inline
    unsigned
    branch_iter<T>::deepness() const
    {
      mln_assertion(is_valid());
      unsigned i = 0;
      tree_node<T>* p = n_;
      while (p)
      {
        p = p->parent();
        i++;
      }
      return i;
    }

    template <typename T>
    inline
    bool
    branch_iter<T>::is_valid() const
    {
      return n_ != 0;
    }

    template <typename T>
    inline
    void
    branch_iter<T>::invalidate()
    {
      n_ = 0;
    }


    template <typename T>
    inline
    void
    branch_iter<T>::start()
    {
      s_.push(iter_pair(branch_.apex().children().begin(),
                        branch_.apex().children().end()));
      n_ = &branch_.apex();
    }

    template <typename T>
    inline
    void
    branch_iter<T>::next()
    {
      if (s_.size() == 0)
        invalidate();
      else
      {
        if (s_.top().first == s_.top().second)
        {
          s_.pop();
          next();
          return;
        }
        else
        {
          n_ = *(s_.top().first);
          s_.top().first++;

          if (!n_)
          {
            next();
            return;
          }

          mln_assertion(n_);
          if (n_->children().size() > 0)
          {
            s_.push(iter_pair(n_->children().begin(),
                              n_->children().end()));
          }
          return;
        }
      }
    }

# endif // ! MLN_INCLUDE_ONLY


  }

} // end of namespace mln


#endif // ! MLN_UTIL_BRANCH_ITER_HH