RhodeCode

    typedef _Digraph Digraph;

    typedef typename Digraph::Arc Arc;

    typedef _PredMatrixMap PredMatrixMap;

    PredMatrixMapPath(const Digraph& _digraph,

                      const PredMatrixMap& _predMatrixMap,

                      typename Digraph::Node _source,

                      typename Digraph::Node _target)

      : digraph(_digraph), predMatrixMap(_predMatrixMap),

        source(_source), target(_target) {}

    int length() const {

      int len = 0;

      typename Digraph::Node node = target;

      typename Digraph::Arc arc;

      while ((arc = predMatrixMap(source, node)) != INVALID) {

        node = digraph.source(arc);

        ++len;

      }

      return len;

    }

    bool empty() const {

    }

    class RevArcIt {

    public:

      RevArcIt() {}

      RevArcIt(Invalid) : path(0), current(INVALID) {}

      RevArcIt(const PredMatrixMapPath& _path)

        : path(&_path), current(_path.target) {

        if (path->predMatrixMap(path->source, current) == INVALID)

          current = INVALID;

      }

      operator const typename Digraph::Arc() const {

        return path->predMatrixMap(path->source, current);

      }

      RevArcIt& operator++() {

        current =

          path->digraph.source(path->predMatrixMap(path->source, current));

        if (path->predMatrixMap(path->source, current) == INVALID)

          current = INVALID;

        return *this;

      }