RhodeCode

      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) {