RhodeCode

The \e LGF can contain extra sections, but there is no restriction on

the format of such sections.

    class Section {

    public:

      virtual ~Section() {}

      virtual void process(std::istream& is, int& line_num) = 0;

    };

    template <typename Functor>

    class LineSection : public Section {

    private:

      Functor _functor;

    public:

      LineSection(const Functor& functor) : _functor(functor) {}

      virtual ~LineSection() {}

      virtual void process(std::istream& is, int& line_num) {

	char c;

	std::string line;

	while (is.get(c) && c != '@') {

	  if (c == '\n') {

	    ++line_num;

	  } else if (c == '#') {

	    getline(is, line);

	    ++line_num;

	  } else if (!isWhiteSpace(c)) {

	    is.putback(c);

	    getline(is, line);

	    _functor(line);

	    ++line_num;

	  }

	}

	if (is) is.putback(c);

	else if (is.eof()) is.clear();

      }

    };

    template <typename Functor>

    class StreamSection : public Section {

    private:

      Functor _functor;

    public:

      StreamSection(const Functor& functor) : _functor(functor) {}

      virtual ~StreamSection() {} 

      virtual void process(std::istream& is, int& line_num) {

	_functor(is, line_num);

	char c;

	std::string line;

	while (is.get(c) && c != '@') {

	  if (c == '\n') {

	    ++line_num;

	  } else if (!isWhiteSpace(c)) {

	    getline(is, line);

	    ++line_num;

	  }

	}

	if (is) is.putback(c);

	else if (is.eof()) is.clear();	

      }

    };

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

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

  /// is set, it will determine how the tokens in the file should be

  /// is converted to the map's value type. If the functor is not set,

  /// then a default conversion will be used. One map can be read into

  /// multiple map objects at the same time. The \c attribute(), \c

  /// node() and \c arc() functions are used to add attribute reading

  /// rules.

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

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

  /// also can load extra sections with the \c sectionLines() and

  /// sectionStream() functions.

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

    Sections _sections;

      _sections.swap(other._sections);

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

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

	delete it->second;

      }

    /// \name Section readers

    /// @{

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

    ///

    /// In the \e LGF file extra sections can be placed, which contain

    /// any data in arbitrary format. These sections can be read with

    /// this function line by line. 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 stipped 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 an 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>

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

      LEMON_ASSERT(!type.empty(), "Type is not empty.");

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

		   "Multiple reading of section.");

      LEMON_ASSERT(type != "nodes" && type != "arcs" && type != "edges" &&

		   type != "attributes", "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

    ///

    /// In the \e LGF file extra sections can be placed, which contain

    /// any data in arbitrary format. These sections can be read

    /// directly with this function. The first parameter is the type

    /// of the section, the second is a functor, which takes an \c

    /// std::istream& and an 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>

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

      LEMON_ASSERT(!type.empty(), "Type is not empty.");

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

		   "Multiple reading of section.");

      LEMON_ASSERT(type != "nodes" && type != "arcs" && type != "edges" &&

		   type != "attributes", "Multiple reading of section.");

      _sections.insert(std::make_pair(type, 

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

      return *this;

    }    

    /// @}

      std::set<std::string> extra_sections;

	    if (extra_sections.find(section) != extra_sections.end()) {

	      std::ostringstream msg;

	      msg << "Multiple occurence of section " << section;

	      throw DataFormatError(msg.str().c_str());

	    }

	    Sections::iterator it = _sections.find(section);

	    if (it != _sections.end()) {

	      extra_sections.insert(section);

	      it->second->process(*_is, line_num);

	      readLine();

	    } else {

	      readLine();

	      skipSection();

	    }