RhodeCode

  ///\code

  /// DigraphReader<Digraph>(digraph, std::cin).

  ///   nodeMap("coordinates", coord_map).

  ///   arcMap("capacity", cap_map).

  ///   node("source", src).

  ///   node("target", trg).

  ///   attribute("caption", caption).

  ///   run();

  ///\endcode

  ///

  /// By default the reader uses the first section in the file of the

  /// proper type. If a section has an optional name, then it can be

  /// selected for reading by giving an optional name parameter to the

  /// \c nodes(), \c arcs() or \c attributes() functions.

  ///

  /// The \c useNodes() and \c useArcs() functions are used to tell the reader

  /// that the nodes or arcs should not be constructed (added to the

  /// graph) during the reading, but instead the label map of the items

  /// are given as a parameter of these functions. An

  /// application of these functions is multipass reading, which is

  /// important if two \c \@arcs sections must be read from the

  /// file. In this case the first phase would read the node set and one

  /// of the arc sets, while the second phase would read the second arc

  /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).

  /// The previously read label node map should be passed to the \c

  /// useNodes() functions. Another application of multipass reading when

  /// paths are given as a node map or an arc map.

  /// It is impossible to read this in

  /// a single pass, because the arcs are not constructed when the node

  /// maps are read.

  template <typename _Digraph>

  class DigraphReader {

  public:

    typedef _Digraph Digraph;

    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);

  private:

    std::istream* _is;

    bool local_is;

    std::string _filename;

    Digraph& _digraph;

    std::string _nodes_caption;

    std::string _arcs_caption;

    std::string _attributes_caption;

    typedef std::map<std::string, Node> NodeIndex;

    NodeIndex _node_index;

    typedef std::map<std::string, Arc> ArcIndex;

    ArcIndex _arc_index;

    typedef std::vector<std::pair<std::string,

      _reader_bits::MapStorageBase<Node>*> > NodeMaps;

    NodeMaps _node_maps;

    typedef std::vector<std::pair<std::string,

      _reader_bits::MapStorageBase<Arc>*> >ArcMaps;

    ArcMaps _arc_maps;

    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>

      Attributes;

    Attributes _attributes;

    bool _use_nodes;

    bool _use_arcs;

    bool _skip_nodes;

    bool _skip_arcs;

    int line_num;

    std::istringstream line;

  public:

    /// \brief Constructor

    ///

    /// Construct a directed graph reader, which reads from the given

    /// input stream.

    DigraphReader(Digraph& digraph, std::istream& is = std::cin)

      : _is(&is), local_is(false), _digraph(digraph),

        _use_nodes(false), _use_arcs(false),

        _skip_nodes(false), _skip_arcs(false) {}

    /// \brief Constructor

    ///

    /// Construct a directed graph reader, which reads from the given

    /// file.

    DigraphReader(Digraph& digraph, const std::string& fn)

      : _is(new std::ifstream(fn.c_str())), local_is(true),

        _filename(fn), _digraph(digraph),

        _use_nodes(false), _use_arcs(false),

        _skip_nodes(false), _skip_arcs(false) {

    }

    /// \brief Constructor

    ///

    /// Construct a directed graph reader, which reads from the given

    /// file.

    DigraphReader(Digraph& digraph, const char* fn)

      : _is(new std::ifstream(fn)), local_is(true),

        _filename(fn), _digraph(digraph),

        _use_nodes(false), _use_arcs(false),

        _skip_nodes(false), _skip_arcs(false) {

    }

    /// \brief Destructor

    ~DigraphReader() {

      for (typename NodeMaps::iterator it = _node_maps.begin();

           it != _node_maps.end(); ++it) {

        delete it->second;

      }

      for (typename ArcMaps::iterator it = _arc_maps.begin();

           it != _arc_maps.end(); ++it) {

        delete it->second;

      }

      for (typename Attributes::iterator it = _attributes.begin();

           it != _attributes.end(); ++it) {

        delete it->second;

      }

      if (local_is) {

        delete _is;

      }

    }

  private:

    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,

                                                  std::istream& is);

    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,

                                                  const std::string& fn);

    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,

                                                  const char *fn);

    DigraphReader(DigraphReader& other)

      : _is(other._is), local_is(other.local_is), _digraph(other._digraph),

        _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),

        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {

      other._is = 0;

      other.local_is = false;

      _node_index.swap(other._node_index);

      _arc_index.swap(other._arc_index);

      _node_maps.swap(other._node_maps);

      _arc_maps.swap(other._arc_maps);

      _attributes.swap(other._attributes);

      _nodes_caption = other._nodes_caption;

      _arcs_caption = other._arcs_caption;

      _attributes_caption = other._attributes_caption;

    }

    DigraphReader& operator=(const DigraphReader&);

  public:

    /// \name Reading rules

    /// @{

    /// \brief Node map reading rule

    ///

    /// Add a node map reading rule to the reader.

    template <typename Map>

    DigraphReader& nodeMap(const std::string& caption, Map& map) {

      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();

      _reader_bits::MapStorageBase<Node>* storage =

        new _reader_bits::MapStorage<Node, Map>(map);

      _node_maps.push_back(std::make_pair(caption, storage));

      return *this;

    }

    /// \brief Node map reading rule

    ///

    /// Add a node map reading rule with specialized converter to the

    /// reader.

    template <typename Map, typename Converter>

    DigraphReader& nodeMap(const std::string& caption, Map& map,

                           const Converter& converter = Converter()) {

      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();

      _reader_bits::MapStorageBase<Node>* storage =

        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);

      _node_maps.push_back(std::make_pair(caption, storage));

      return *this;

    }

    /// \brief Arc map reading rule

    ///

    /// Add an arc map reading rule to the reader.

    template <typename Map>

    DigraphReader& arcMap(const std::string& caption, Map& map) {

      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();

      _reader_bits::MapStorageBase<Arc>* storage =

        new _reader_bits::MapStorage<Arc, Map>(map);

    return tmp;

  }

  template <typename Graph>

  class GraphReader;

  template <typename Graph>

  GraphReader<Graph> graphReader(Graph& graph,

                                 std::istream& is = std::cin);

  template <typename Graph>

  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn);

  template <typename Graph>

  GraphReader<Graph> graphReader(Graph& graph, const char *fn);

  /// \ingroup lemon_io

  ///

  /// \brief \ref lgf-format "LGF" reader for undirected graphs

  ///

  /// This utility reads an \ref lgf-format "LGF" file.

  ///

  /// It can be used almost the same way as \c DigraphReader.

  /// The only difference is that this class can handle edges and

  /// edge maps as well as arcs and arc maps.

  ///

  /// The columns in the \c \@edges (or \c \@arcs) section are the

  /// edge maps. However, if there are two maps with the same name

  /// prefixed with \c '+' and \c '-', then these can be read into an

  /// arc map.  Similarly, an attribute can be read into an arc, if

  /// it's value is an edge label prefixed with \c '+' or \c '-'.

  template <typename _Graph>

  class GraphReader {

  public:

    typedef _Graph Graph;

    TEMPLATE_GRAPH_TYPEDEFS(Graph);

  private:

    std::istream* _is;

    bool local_is;

    std::string _filename;

    Graph& _graph;

    std::string _nodes_caption;

    std::string _edges_caption;

    std::string _attributes_caption;

    typedef std::map<std::string, Node> NodeIndex;

    NodeIndex _node_index;

    typedef std::map<std::string, Edge> EdgeIndex;

    EdgeIndex _edge_index;

    typedef std::vector<std::pair<std::string,

      _reader_bits::MapStorageBase<Node>*> > NodeMaps;

    NodeMaps _node_maps;

    typedef std::vector<std::pair<std::string,

      _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;

    EdgeMaps _edge_maps;

    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>

      Attributes;

    Attributes _attributes;

    bool _use_nodes;

    bool _use_edges;

    bool _skip_nodes;

    bool _skip_edges;

    int line_num;

    std::istringstream line;

  public:

    /// \brief Constructor

    ///

    /// Construct an undirected graph reader, which reads from the given

    /// input stream.

    GraphReader(Graph& graph, std::istream& is = std::cin)

      : _is(&is), local_is(false), _graph(graph),

        _use_nodes(false), _use_edges(false),

        _skip_nodes(false), _skip_edges(false) {}

    /// \brief Constructor

    ///

    /// Construct an undirected graph reader, which reads from the given

    /// file.

    GraphReader(Graph& graph, const std::string& fn)

      : _is(new std::ifstream(fn.c_str())), local_is(true),

        _filename(fn), _graph(graph),

        _use_nodes(false), _use_edges(false),

        _skip_nodes(false), _skip_edges(false) {

    }

    /// \brief Constructor

    ///

    /// Construct an undirected graph reader, which reads from the given

    /// file.

    GraphReader(Graph& graph, const char* fn)

      : _is(new std::ifstream(fn)), local_is(true),

        _filename(fn), _graph(graph),

        _use_nodes(false), _use_edges(false),

        _skip_nodes(false), _skip_edges(false) {

    }

    /// \brief Destructor

    ~GraphReader() {

      for (typename NodeMaps::iterator it = _node_maps.begin();

           it != _node_maps.end(); ++it) {

        delete it->second;

      }

      for (typename EdgeMaps::iterator it = _edge_maps.begin();

           it != _edge_maps.end(); ++it) {

        delete it->second;

      }

      for (typename Attributes::iterator it = _attributes.begin();

           it != _attributes.end(); ++it) {

        delete it->second;

      }

      if (local_is) {

        delete _is;

      }

    }

  private:

    friend GraphReader<Graph> graphReader<>(Graph& graph, std::istream& is);

    friend GraphReader<Graph> graphReader<>(Graph& graph,

                                            const std::string& fn);

    friend GraphReader<Graph> graphReader<>(Graph& graph, const char *fn);

    GraphReader(GraphReader& other)

      : _is(other._is), local_is(other.local_is), _graph(other._graph),

        _use_nodes(other._use_nodes), _use_edges(other._use_edges),

        _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {

      other._is = 0;

      other.local_is = false;

      _node_index.swap(other._node_index);

      _edge_index.swap(other._edge_index);

      _node_maps.swap(other._node_maps);

      _edge_maps.swap(other._edge_maps);

      _attributes.swap(other._attributes);

      _nodes_caption = other._nodes_caption;

      _edges_caption = other._edges_caption;

      _attributes_caption = other._attributes_caption;

    }

    GraphReader& operator=(const GraphReader&);

  public:

    /// \name Reading rules

    /// @{

    /// \brief Node map reading rule

    ///

    /// Add a node map reading rule to the reader.

    template <typename Map>

    GraphReader& nodeMap(const std::string& caption, Map& map) {

      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();

      _reader_bits::MapStorageBase<Node>* storage =

        new _reader_bits::MapStorage<Node, Map>(map);

      _node_maps.push_back(std::make_pair(caption, storage));

      return *this;

    }

    /// \brief Node map reading rule

    ///

    /// Add a node map reading rule with specialized converter to the

    /// reader.

    template <typename Map, typename Converter>

    GraphReader& nodeMap(const std::string& caption, Map& map,

                           const Converter& converter = Converter()) {

      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();

      _reader_bits::MapStorageBase<Node>* storage =

        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);

      _node_maps.push_back(std::make_pair(caption, storage));

      return *this;

    }

    /// \brief Edge map reading rule

    ///

    /// Add an edge map reading rule to the reader.

    template <typename Map>

    GraphReader& edgeMap(const std::string& caption, Map& map) {

      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();

      _reader_bits::MapStorageBase<Edge>* storage =

        new _reader_bits::MapStorage<Edge, Map>(map);

      _edge_maps.push_back(std::make_pair(caption, storage));

      return *this;

    }

        }

      }

      if (!nodes_done) {

        throw FormatError("Section @nodes not found");

      }

      if (!edges_done) {

        throw FormatError("Section @edges not found");

      }

      if (!attributes_done && !_attributes.empty()) {

        throw FormatError("Section @attributes not found");

      }

    }

    /// @}

  };

  /// \brief Return a \ref GraphReader class

  ///

  /// This function just returns a \ref GraphReader class.

  /// \relates GraphReader

  template <typename Graph>

  GraphReader<Graph> graphReader(Graph& graph, std::istream& is = std::cin) {

    GraphReader<Graph> tmp(graph, is);

    return tmp;

  }

  /// \brief Return a \ref GraphReader class

  ///

  /// This function just returns a \ref GraphReader class.

  /// \relates GraphReader

  template <typename Graph>

  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {

    GraphReader<Graph> tmp(graph, fn);

    return tmp;

  }

  /// \brief Return a \ref GraphReader class

  ///

  /// This function just returns a \ref GraphReader class.

  /// \relates GraphReader

  template <typename Graph>

  GraphReader<Graph> graphReader(Graph& graph, const char* fn) {

    GraphReader<Graph> tmp(graph, fn);

    return tmp;

  }

  class SectionReader;

  SectionReader sectionReader(std::istream& is);

  SectionReader sectionReader(const std::string& fn);

  SectionReader sectionReader(const char* fn);

  /// \ingroup lemon_io

  ///

  /// \brief Section reader class

  ///

  /// In the \ref lgf-format "LGF" file extra sections can be placed,

  /// which contain any data in arbitrary format. Such sections can be

  /// read with this class. A reading rule can be added to the class

  /// with two different functions. With the \c sectionLines() function a

  /// functor can process the section line-by-line, while with the \c

  /// sectionStream() member the section can be read from an input

  /// stream.

  class SectionReader {

  private:

    std::istream* _is;

    bool local_is;

    std::string _filename;

    typedef std::map<std::string, _reader_bits::Section*> Sections;

    Sections _sections;

    int line_num;

    std::istringstream line;

  public:

    /// \brief Constructor

    ///

    /// Construct a section reader, which reads from the given input

    /// stream.

    SectionReader(std::istream& is)

      : _is(&is), local_is(false) {}

    /// \brief Constructor

    ///

    /// Construct a section reader, which reads from the given file.

    SectionReader(const std::string& fn)

      : _is(new std::ifstream(fn.c_str())), local_is(true),

        _filename(fn) {

    }

    /// \brief Constructor

    ///

    /// Construct a section reader, which reads from the given file.

    SectionReader(const char* fn)

      : _is(new std::ifstream(fn)), local_is(true),

        _filename(fn) {

    }

    /// \brief Destructor

    ~SectionReader() {

      for (Sections::iterator it = _sections.begin();

           it != _sections.end(); ++it) {

        delete it->second;

      }

      if (local_is) {

        delete _is;

      }

    }

  private:

    friend SectionReader sectionReader(std::istream& is);

    friend SectionReader sectionReader(const std::string& fn);

    friend SectionReader sectionReader(const char* fn);

    SectionReader(SectionReader& other)

      : _is(other._is), local_is(other.local_is) {

      other._is = 0;

      other.local_is = false;

      _sections.swap(other._sections);

    }

    SectionReader& operator=(const SectionReader&);

  public:

    /// \name Section readers

    /// @{

    /// \brief Add a section processor with line oriented reading

    ///

    /// The first parameter is the type descriptor of the section, the

    /// second is a functor, which takes just one \c std::string

    /// parameter. At the reading process, each line of the section

    /// will be given to the functor object. However, the empty lines

    /// and the comment lines are filtered out, and the leading

    /// whitespaces are trimmed from each processed string.

    ///

    /// For example let's see a section, which contain several

    /// integers, which should be inserted into a vector.

    ///\code

    ///  @numbers

    ///  12 45 23

    ///  4

    ///  23 6

    ///\endcode

    ///

    /// The functor is implemented as a struct:

    ///\code

    ///  struct NumberSection {

    ///    std::vector<int>& _data;

    ///    NumberSection(std::vector<int>& data) : _data(data) {}

    ///    void operator()(const std::string& line) {

    ///      std::istringstream ls(line);

    ///      int value;

    ///      while (ls >> value) _data.push_back(value);

    ///    }

    ///  };

    ///

    ///  // ...

    ///

    ///  reader.sectionLines("numbers", NumberSection(vec));

    ///\endcode

    template <typename Functor>

    SectionReader& sectionLines(const std::string& type, Functor functor) {

      LEMON_ASSERT(!type.empty(), "Type is empty.");

      LEMON_ASSERT(_sections.find(type) == _sections.end(),

                   "Multiple reading of section.");

      _sections.insert(std::make_pair(type,

        new _reader_bits::LineSection<Functor>(functor)));

      return *this;

    }

    /// \brief Add a section processor with stream oriented reading

    ///

    /// The first parameter is the type of the section, the second is

    /// a functor, which takes an \c std::istream& and an \c int&

    /// parameter, the latter regard to the line number of stream. The

    /// functor can read the input while the section go on, and the

    /// line number should be modified accordingly.

    template <typename Functor>

    SectionReader& sectionStream(const std::string& type, Functor functor) {

      LEMON_ASSERT(!type.empty(), "Type is empty.");

      LEMON_ASSERT(_sections.find(type) == _sections.end(),

                   "Multiple reading of section.");

      _sections.insert(std::make_pair(type,

         new _reader_bits::StreamSection<Functor>(functor)));

    /// @}

  };

  /// \brief Return a \ref SectionReader class

  ///

  /// This function just returns a \ref SectionReader class.

  /// \relates SectionReader

  inline SectionReader sectionReader(std::istream& is) {

    SectionReader tmp(is);

    return tmp;

  }

  /// \brief Return a \ref SectionReader class

  ///

  /// This function just returns a \ref SectionReader class.

  /// \relates SectionReader

  inline SectionReader sectionReader(const std::string& fn) {

    SectionReader tmp(fn);

    return tmp;

  }

  /// \brief Return a \ref SectionReader class

  ///

  /// This function just returns a \ref SectionReader class.

  /// \relates SectionReader

  inline SectionReader sectionReader(const char* fn) {

    SectionReader tmp(fn);

    return tmp;

  }

  /// \ingroup lemon_io

  ///

  /// \brief Reader for the contents of the \ref lgf-format "LGF" file

  ///

  /// This class can be used to read the sections, the map names and

  /// the attributes from a file. Usually, the LEMON programs know

  /// that, which type of graph, which maps and which attributes

  /// should be read from a file, but in general tools (like glemon)

  /// the contents of an LGF file should be guessed somehow. This class

  /// reads the graph and stores the appropriate information for

  /// reading the graph.

  ///

  ///\code

  /// LgfContents contents("graph.lgf");

  /// contents.run();

  ///

  /// // Does it contain any node section and arc section?

  /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {

  ///   std::cerr << "Failure, cannot find graph." << std::endl;

  ///   return -1;

  /// }

  /// std::cout << "The name of the default node section: "

  ///           << contents.nodeSection(0) << std::endl;

  /// std::cout << "The number of the arc maps: "

  ///           << contents.arcMaps(0).size() << std::endl;

  /// std::cout << "The name of second arc map: "

  ///           << contents.arcMaps(0)[1] << std::endl;

  ///\endcode

  class LgfContents {

  private:

    std::istream* _is;

    bool local_is;

    std::vector<std::string> _node_sections;

    std::vector<std::string> _edge_sections;

    std::vector<std::string> _attribute_sections;

    std::vector<std::string> _extra_sections;

    std::vector<bool> _arc_sections;

    std::vector<std::vector<std::string> > _node_maps;

    std::vector<std::vector<std::string> > _edge_maps;

    std::vector<std::vector<std::string> > _attributes;

    int line_num;

    std::istringstream line;

  public:

    /// \brief Constructor

    ///

    /// Construct an \e LGF contents reader, which reads from the given

    /// input stream.

    LgfContents(std::istream& is)

      : _is(&is), local_is(false) {}

    /// \brief Constructor

    ///

    /// Construct an \e LGF contents reader, which reads from the given

    /// file.

    LgfContents(const std::string& fn)

      : _is(new std::ifstream(fn.c_str())), local_is(true) {

    }

    /// \brief Constructor

    ///

    /// Construct an \e LGF contents reader, which reads from the given

    /// file.

    LgfContents(const char* fn)

      : _is(new std::ifstream(fn)), local_is(true) {

    }

    /// \brief Destructor

    ~LgfContents() {

      if (local_is) delete _is;

    }

  private:

    LgfContents(const LgfContents&);

    LgfContents& operator=(const LgfContents&);

  public:

    /// \name Node sections

    /// @{

    /// \brief Gives back the number of node sections in the file.

    ///

    /// Gives back the number of node sections in the file.

    int nodeSectionNum() const {

      return _node_sections.size();

    }

    /// \brief Returns the node section name at the given position.

    ///

    /// Returns the node section name at the given position.

    const std::string& nodeSection(int i) const {

      return _node_sections[i];

    }

    /// \brief Gives back the node maps for the given section.

    ///

    /// Gives back the node maps for the given section.

    const std::vector<std::string>& nodeMapNames(int i) const {

      return _node_maps[i];

    }

    /// @}

    /// \name Arc/Edge sections

    /// @{

    /// \brief Gives back the number of arc/edge sections in the file.

    ///

    /// Gives back the number of arc/edge sections in the file.

    /// \note It is synonym of \c edgeSectionNum().

    int arcSectionNum() const {

      return _edge_sections.size();

    }

    /// \brief Returns the arc/edge section name at the given position.

    ///

    /// Returns the arc/edge section name at the given position.

    /// \note It is synonym of \c edgeSection().

    const std::string& arcSection(int i) const {

      return _edge_sections[i];

    }

    /// \brief Gives back the arc/edge maps for the given section.

    ///

    /// Gives back the arc/edge maps for the given section.

    /// \note It is synonym of \c edgeMapNames().

    const std::vector<std::string>& arcMapNames(int i) const {

      return _edge_maps[i];

    }

    /// @}

    /// \name Synonyms

    /// @{

    /// \brief Gives back the number of arc/edge sections in the file.

    ///

    /// Gives back the number of arc/edge sections in the file.

    /// \note It is synonym of \c arcSectionNum().

    int edgeSectionNum() const {

      return _edge_sections.size();

    }

    /// \brief Returns the section name at the given position.

    ///

    /// Returns the section name at the given position.

    /// \note It is synonym of \c arcSection().

    const std::string& edgeSection(int i) const {

      return _edge_sections[i];

    }

    /// \brief Gives back the edge maps for the given section.

    ///

    /// Gives back the edge maps for the given section.

    /// \note It is synonym of \c arcMapNames().

    const std::vector<std::string>& edgeMapNames(int i) const {

      return _edge_maps[i];

    }

  /// This utility writes an \ref lgf-format "LGF" file.

  ///

  /// The writing method does a batch processing. The user creates a

  /// writer object, then various writing rules can be added to the

  /// writer, and eventually the writing is executed with the \c run()

  /// member function. A map writing rule can be added to the writer

  /// with the \c nodeMap() or \c arcMap() members. An optional

  /// converter parameter can also be added as a standard functor

  /// converting from the value type of the map to \c std::string. If it

  /// is set, it will determine how the value type of the map is written to

  /// the output stream. If the functor is not set, then a default

  /// conversion will be used. The \c attribute(), \c node() and \c

  /// arc() functions are used to add attribute writing rules.

  ///

  ///\code

  /// DigraphWriter<Digraph>(digraph, std::cout).

  ///   nodeMap("coordinates", coord_map).

  ///   nodeMap("size", size).

  ///   nodeMap("title", title).

  ///   arcMap("capacity", cap_map).

  ///   node("source", src).

  ///   node("target", trg).

  ///   attribute("caption", caption).

  ///   run();

  ///\endcode

  ///

  ///

  /// By default, the writer does not write additional captions to the

  /// sections, but they can be give as an optional parameter of

  /// the \c nodes(), \c arcs() or \c

  /// attributes() functions.

  ///

  /// The \c skipNodes() and \c skipArcs() functions forbid the

  /// writing of the sections. If two arc sections should be written

  /// to the output, it can be done in two passes, the first pass

  /// writes the node section and the first arc section, then the

  /// second pass skips the node section and writes just the arc

  /// section to the stream. The output stream can be retrieved with

  /// the \c ostream() function, hence the second pass can append its

  /// output to the output of the first pass.

  template <typename _Digraph>

  class DigraphWriter {

  public:

    typedef _Digraph Digraph;

    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);

  private:

    std::ostream* _os;

    bool local_os;

    const Digraph& _digraph;

    std::string _nodes_caption;

    std::string _arcs_caption;

    std::string _attributes_caption;

    typedef std::map<Node, std::string> NodeIndex;

    NodeIndex _node_index;

    typedef std::map<Arc, std::string> ArcIndex;

    ArcIndex _arc_index;

    typedef std::vector<std::pair<std::string,

      _writer_bits::MapStorageBase<Node>* > > NodeMaps;

    NodeMaps _node_maps;

    typedef std::vector<std::pair<std::string,

      _writer_bits::MapStorageBase<Arc>* > >ArcMaps;

    ArcMaps _arc_maps;

    typedef std::vector<std::pair<std::string,

      _writer_bits::ValueStorageBase*> > Attributes;

    Attributes _attributes;

    bool _skip_nodes;

    bool _skip_arcs;

  public:

    /// \brief Constructor

    ///

    /// Construct a directed graph writer, which writes to the given

    /// output stream.

    DigraphWriter(const Digraph& digraph, std::ostream& os = std::cout)

      : _os(&os), local_os(false), _digraph(digraph),

        _skip_nodes(false), _skip_arcs(false) {}

    /// \brief Constructor

    ///

    /// Construct a directed graph writer, which writes to the given

    /// output file.

    DigraphWriter(const Digraph& digraph, const std::string& fn)

      : _os(new std::ofstream(fn.c_str())), local_os(true), _digraph(digraph),

        _skip_nodes(false), _skip_arcs(false) {

    }

    /// \brief Constructor

    ///

    /// Construct a directed graph writer, which writes to the given

    /// output file.

    DigraphWriter(const Digraph& digraph, const char* fn)

      : _os(new std::ofstream(fn)), local_os(true), _digraph(digraph),

        _skip_nodes(false), _skip_arcs(false) {

    }

    /// \brief Destructor

    ~DigraphWriter() {

      for (typename NodeMaps::iterator it = _node_maps.begin();

           it != _node_maps.end(); ++it) {

        delete it->second;

      }

      for (typename ArcMaps::iterator it = _arc_maps.begin();

           it != _arc_maps.end(); ++it) {

        delete it->second;

      }

      for (typename Attributes::iterator it = _attributes.begin();

           it != _attributes.end(); ++it) {

        delete it->second;

      }

      if (local_os) {

        delete _os;

      }

    }

  private:

    friend DigraphWriter<Digraph> digraphWriter<>(const Digraph& digraph,

                                                  std::ostream& os);

    friend DigraphWriter<Digraph> digraphWriter<>(const Digraph& digraph,

                                                  const std::string& fn);

    friend DigraphWriter<Digraph> digraphWriter<>(const Digraph& digraph,

                                                  const char *fn);

    DigraphWriter(DigraphWriter& other)

      : _os(other._os), local_os(other.local_os), _digraph(other._digraph),

        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {

      other._os = 0;

      other.local_os = false;

      _node_index.swap(other._node_index);

      _arc_index.swap(other._arc_index);

      _node_maps.swap(other._node_maps);

      _arc_maps.swap(other._arc_maps);

      _attributes.swap(other._attributes);

      _nodes_caption = other._nodes_caption;

      _arcs_caption = other._arcs_caption;

      _attributes_caption = other._attributes_caption;

    }

    DigraphWriter& operator=(const DigraphWriter&);

  public:

    /// \name Writing rules

    /// @{

    /// \brief Node map writing rule

    ///

    /// Add a node map writing rule to the writer.

    template <typename Map>

    DigraphWriter& nodeMap(const std::string& caption, const Map& map) {

      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();

      _writer_bits::MapStorageBase<Node>* storage =

        new _writer_bits::MapStorage<Node, Map>(map);

      _node_maps.push_back(std::make_pair(caption, storage));

      return *this;

    }

    /// \brief Node map writing rule

    ///

    /// Add a node map writing rule with specialized converter to the

    /// writer.

    template <typename Map, typename Converter>

    DigraphWriter& nodeMap(const std::string& caption, const Map& map,

                           const Converter& converter = Converter()) {

      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();

      _writer_bits::MapStorageBase<Node>* storage =

        new _writer_bits::MapStorage<Node, Map, Converter>(map, converter);

      _node_maps.push_back(std::make_pair(caption, storage));

      return *this;

    }

    /// \brief Arc map writing rule

    ///

    /// Add an arc map writing rule to the writer.

    template <typename Map>

    DigraphWriter& arcMap(const std::string& caption, const Map& map) {

      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();

      _writer_bits::MapStorageBase<Arc>* storage =

        new _writer_bits::MapStorage<Arc, Map>(map);

      _arc_maps.push_back(std::make_pair(caption, storage));

      return *this;

    }

  /// \brief Return a \ref DigraphWriter class

  ///

  /// This function just returns a \ref DigraphWriter class.

  /// \relates DigraphWriter

  template <typename Digraph>

  DigraphWriter<Digraph> digraphWriter(const Digraph& digraph,

                                       const char* fn) {

    DigraphWriter<Digraph> tmp(digraph, fn);

    return tmp;

  }

  template <typename Graph>

  class GraphWriter;

  template <typename Graph>

  GraphWriter<Graph> graphWriter(const Graph& graph,

                                 std::ostream& os = std::cout);

  template <typename Graph>

  GraphWriter<Graph> graphWriter(const Graph& graph, const std::string& fn);

  template <typename Graph>

  GraphWriter<Graph> graphWriter(const Graph& graph, const char *fn);

  /// \ingroup lemon_io

  ///

  /// \brief \ref lgf-format "LGF" writer for directed graphs

  ///

  /// This utility writes an \ref lgf-format "LGF" file.

  ///

  /// It can be used almost the same way as \c DigraphWriter.

  /// The only difference is that this class can handle edges and

  /// edge maps as well as arcs and arc maps.

  ///

  /// The arc maps are written into the file as two columns, the

  /// caption of the columns are the name of the map prefixed with \c

  /// '+' and \c '-'. The arcs are written into the \c \@attributes

  /// section as a \c '+' or a \c '-' prefix (depends on the direction

  /// of the arc) and the label of corresponding edge.

  template <typename _Graph>

  class GraphWriter {

  public:

    typedef _Graph Graph;

    TEMPLATE_GRAPH_TYPEDEFS(Graph);