lemon/lgf_writer.h
author Balazs Dezso <deba@inf.elte.hu>
Mon, 16 Jun 2008 18:23:11 +0200
changeset 173 b026e9779b28
parent 163 c82fd9568d75
child 185 33e45a9b868c
permissions -rw-r--r--
LGF content reader class
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2008
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 ///\ingroup lemon_io
    20 ///\file
    21 ///\brief Lemon Graph Format writer.
    22 
    23 
    24 #ifndef LEMON_LGF_WRITER_H
    25 #define LEMON_LGF_WRITER_H
    26 
    27 #include <iostream>
    28 #include <fstream>
    29 #include <sstream>
    30 
    31 #include <algorithm>
    32 
    33 #include <vector>
    34 #include <functional>
    35 
    36 #include <lemon/assert.h>
    37 #include <lemon/graph_utils.h>
    38 
    39 namespace lemon {
    40 
    41   namespace _writer_bits {
    42 
    43     template <typename Value>
    44     struct DefaultConverter {
    45       std::string operator()(const Value& value) {
    46 	std::ostringstream os;
    47 	os << value;
    48 	return os.str();
    49       }
    50     };
    51 
    52     template <typename T>
    53     bool operator<(const T&, const T&) {
    54       throw DataFormatError("Label map is not comparable");
    55     }
    56 
    57     template <typename _Map>
    58     class MapLess {
    59     public:
    60       typedef _Map Map;
    61       typedef typename Map::Key Item;
    62 
    63     private:
    64       const Map& _map;
    65       
    66     public:
    67       MapLess(const Map& map) : _map(map) {}
    68 
    69       bool operator()(const Item& left, const Item& right) {
    70 	return _map[left] < _map[right];
    71       }
    72     };
    73 
    74     template <typename _Graph, bool _dir, typename _Map>
    75     class GraphArcMapLess {
    76     public:
    77       typedef _Map Map;
    78       typedef _Graph Graph;
    79       typedef typename Graph::Edge Item;
    80 
    81     private:
    82       const Graph& _graph;
    83       const Map& _map;
    84       
    85     public:
    86       GraphArcMapLess(const Graph& graph, const Map& map) 
    87 	: _graph(graph), _map(map) {}
    88 
    89       bool operator()(const Item& left, const Item& right) {
    90 	return _map[_graph.direct(left, _dir)] < 
    91 	  _map[_graph.direct(right, _dir)];
    92       }
    93     };
    94 
    95     template <typename _Item>    
    96     class MapStorageBase {
    97     public:
    98       typedef _Item Item;
    99 
   100     public:
   101       MapStorageBase() {}
   102       virtual ~MapStorageBase() {}
   103 
   104       virtual std::string get(const Item& item) = 0;
   105       virtual void sort(std::vector<Item>&) = 0;
   106     };
   107 
   108     template <typename _Item, typename _Map, 
   109 	      typename _Converter = DefaultConverter<typename _Map::Value> >
   110     class MapStorage : public MapStorageBase<_Item> {
   111     public:
   112       typedef _Map Map;
   113       typedef _Converter Converter;
   114       typedef _Item Item;
   115       
   116     private:
   117       const Map& _map;
   118       Converter _converter;
   119 
   120     public:
   121       MapStorage(const Map& map, const Converter& converter = Converter()) 
   122 	: _map(map), _converter(converter) {}
   123       virtual ~MapStorage() {}
   124 
   125       virtual std::string get(const Item& item) {
   126 	return _converter(_map[item]);
   127       }
   128       virtual void sort(std::vector<Item>& items) {
   129 	MapLess<Map> less(_map);
   130 	std::sort(items.begin(), items.end(), less);
   131       }
   132     };
   133 
   134     template <typename _Graph, bool _dir, typename _Map, 
   135 	      typename _Converter = DefaultConverter<typename _Map::Value> >
   136     class GraphArcMapStorage : public MapStorageBase<typename _Graph::Edge> {
   137     public:
   138       typedef _Map Map;
   139       typedef _Converter Converter;
   140       typedef _Graph Graph;
   141       typedef typename Graph::Edge Item;
   142       static const bool dir = _dir;
   143       
   144     private:
   145       const Graph& _graph;
   146       const Map& _map;
   147       Converter _converter;
   148 
   149     public:
   150       GraphArcMapStorage(const Graph& graph, const Map& map,  
   151 			 const Converter& converter = Converter()) 
   152 	: _graph(graph), _map(map), _converter(converter) {}
   153       virtual ~GraphArcMapStorage() {}
   154 
   155       virtual std::string get(const Item& item) {
   156 	return _converter(_map[_graph.direct(item, dir)]);
   157       }
   158       virtual void sort(std::vector<Item>& items) {
   159 	GraphArcMapLess<Graph, dir, Map> less(_graph, _map);
   160 	std::sort(items.begin(), items.end(), less);
   161       }
   162     };
   163 
   164     class ValueStorageBase {
   165     public:
   166       ValueStorageBase() {}
   167       virtual ~ValueStorageBase() {}
   168 
   169       virtual std::string get() = 0;      
   170     };
   171 
   172     template <typename _Value, typename _Converter = DefaultConverter<_Value> >
   173     class ValueStorage : public ValueStorageBase {
   174     public:
   175       typedef _Value Value;
   176       typedef _Converter Converter;
   177 
   178     private:
   179       const Value& _value;
   180       Converter _converter;
   181 
   182     public:
   183       ValueStorage(const Value& value, const Converter& converter = Converter())
   184  	: _value(value), _converter(converter) {}
   185 
   186       virtual std::string get() {
   187 	return _converter(_value);
   188       }
   189     };
   190 
   191     template <typename Value>
   192     struct MapLookUpConverter {
   193       const std::map<Value, std::string>& _map;
   194       
   195       MapLookUpConverter(const std::map<Value, std::string>& map) 
   196 	: _map(map) {}
   197       
   198       std::string operator()(const Value& str) {
   199 	typename std::map<Value, std::string>::const_iterator it = 
   200 	  _map.find(str);
   201 	if (it == _map.end()) {
   202 	  throw DataFormatError("Item not found");
   203 	}
   204 	return it->second;
   205       }
   206     };
   207 
   208     template <typename Graph>
   209     struct GraphArcLookUpConverter {
   210       const Graph& _graph;
   211       const std::map<typename Graph::Edge, std::string>& _map;
   212       
   213       GraphArcLookUpConverter(const Graph& graph, 
   214 			      const std::map<typename Graph::Edge, 
   215 			                     std::string>& map) 
   216 	: _graph(graph), _map(map) {}
   217       
   218       std::string operator()(const typename Graph::Arc& val) {
   219 	typename std::map<typename Graph::Edge, std::string>
   220 	  ::const_iterator it = _map.find(val);
   221 	if (it == _map.end()) {
   222 	  throw DataFormatError("Item not found");
   223 	}
   224 	return (_graph.direction(val) ? '+' : '-') + it->second;
   225       }
   226     };
   227 
   228     bool isWhiteSpace(char c) {
   229       return c == ' ' || c == '\t' || c == '\v' || 
   230         c == '\n' || c == '\r' || c == '\f'; 
   231     }
   232 
   233     bool isEscaped(char c) {
   234       return c == '\\' || c == '\"' || c == '\'' || 
   235 	c == '\a' || c == '\b';
   236     }
   237 
   238     static void writeEscape(std::ostream& os, char c) {
   239       switch (c) {
   240       case '\\':
   241 	os << "\\\\";
   242 	return;
   243       case '\"':
   244 	os << "\\\"";
   245 	return;
   246       case '\a':
   247 	os << "\\a";
   248 	return;
   249       case '\b':
   250 	os << "\\b";
   251 	return;
   252       case '\f':
   253 	os << "\\f";
   254 	return;
   255       case '\r':
   256 	os << "\\r";
   257 	return;
   258       case '\n':
   259 	os << "\\n";
   260 	return;
   261       case '\t':
   262 	os << "\\t";
   263 	return;
   264       case '\v':
   265 	os << "\\v";
   266 	return;
   267       default:
   268 	if (c < 0x20) {
   269 	  std::ios::fmtflags flags = os.flags();
   270 	  os << '\\' << std::oct << static_cast<int>(c);
   271 	  os.flags(flags);
   272 	} else {
   273 	  os << c;
   274 	}
   275 	return;
   276       }     
   277     }
   278 
   279     bool requireEscape(const std::string& str) {
   280       if (str.empty() || str[0] == '@') return true;
   281       std::istringstream is(str);
   282       char c;
   283       while (is.get(c)) {
   284 	if (isWhiteSpace(c) || isEscaped(c)) {
   285 	  return true;
   286 	}
   287       }
   288       return false;
   289     }
   290     
   291     std::ostream& writeToken(std::ostream& os, const std::string& str) {
   292 
   293       if (requireEscape(str)) {
   294 	os << '\"';
   295 	for (std::string::const_iterator it = str.begin(); 
   296 	     it != str.end(); ++it) {
   297 	  writeEscape(os, *it);
   298 	}	
   299 	os << '\"';
   300       } else {
   301 	os << str;
   302       }
   303       return os;
   304     }
   305 
   306   }
   307   
   308   /// \ingroup lemon_io
   309   ///  
   310   /// \brief LGF writer for directed graphs
   311   ///
   312   /// This utility writes an \ref lgf-format "LGF" file.
   313   ///
   314   /// The writing method does a batch processing. The user creates a
   315   /// writer object, then various writing rules can be added to the
   316   /// writer, and eventually the writing is executed with the \c run()
   317   /// member function. A map writing rule can be added to the writer
   318   /// with the \c nodeMap() or \c arcMap() members. An optional
   319   /// converter parameter can also be added as a standard functor
   320   /// converting from the value type of the map to std::string. If it
   321   /// is set, it will determine how the map's value type is written to
   322   /// the output stream. If the functor is not set, then a default
   323   /// conversion will be used. The \c attribute(), \c node() and \c
   324   /// arc() functions are used to add attribute writing rules.
   325   ///
   326   ///\code
   327   ///     DigraphWriter<Digraph>(std::cout, digraph).
   328   ///       nodeMap("coordinates", coord_map).
   329   ///       nodeMap("size", size).
   330   ///       nodeMap("title", title).
   331   ///       arcMap("capacity", cap_map).
   332   ///       node("source", src).
   333   ///       node("target", trg).
   334   ///       attribute("caption", caption).
   335   ///       run();
   336   ///\endcode
   337   ///
   338   ///
   339   /// By default, the writer does not write additional captions to the
   340   /// sections, but they can be give as an optional parameter of
   341   /// the \c nodes(), \c arcs() or \c
   342   /// attributes() functions.
   343   ///
   344   /// The \c skipNodes() and \c skipArcs() functions forbid the
   345   /// writing of the sections. If two arc sections should be written
   346   /// to the output, it can be done in two passes, the first pass
   347   /// writes the node section and the first arc section, then the
   348   /// second pass skips the node section and writes just the arc
   349   /// section to the stream. The output stream can be retrieved with
   350   /// the \c ostream() function, hence the second pass can append its
   351   /// output to the output of the first pass.
   352   template <typename _Digraph>
   353   class DigraphWriter {
   354   public:
   355 
   356     typedef _Digraph Digraph;
   357     TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
   358     
   359   private:
   360 
   361 
   362     std::ostream* _os;
   363     bool local_os;
   364 
   365     Digraph& _digraph;
   366 
   367     std::string _nodes_caption;
   368     std::string _arcs_caption;
   369     std::string _attributes_caption;
   370     
   371     typedef std::map<Node, std::string> NodeIndex;
   372     NodeIndex _node_index;
   373     typedef std::map<Arc, std::string> ArcIndex;
   374     ArcIndex _arc_index;
   375 
   376     typedef std::vector<std::pair<std::string, 
   377       _writer_bits::MapStorageBase<Node>* > > NodeMaps;    
   378     NodeMaps _node_maps; 
   379 
   380     typedef std::vector<std::pair<std::string, 
   381       _writer_bits::MapStorageBase<Arc>* > >ArcMaps;
   382     ArcMaps _arc_maps;
   383 
   384     typedef std::vector<std::pair<std::string, 
   385       _writer_bits::ValueStorageBase*> > Attributes;
   386     Attributes _attributes;
   387 
   388     bool _skip_nodes;
   389     bool _skip_arcs;
   390 
   391   public:
   392 
   393     /// \brief Constructor
   394     ///
   395     /// Construct a directed graph writer, which writes to the given
   396     /// output stream.
   397     DigraphWriter(std::ostream& is, Digraph& digraph) 
   398       : _os(&is), local_os(false), _digraph(digraph),
   399 	_skip_nodes(false), _skip_arcs(false) {}
   400 
   401     /// \brief Constructor
   402     ///
   403     /// Construct a directed graph writer, which writes to the given
   404     /// output file.
   405     DigraphWriter(const std::string& fn, Digraph& digraph) 
   406       : _os(new std::ofstream(fn.c_str())), local_os(true), _digraph(digraph),
   407 	_skip_nodes(false), _skip_arcs(false) {}
   408 
   409     /// \brief Constructor
   410     ///
   411     /// Construct a directed graph writer, which writes to the given
   412     /// output file.
   413     DigraphWriter(const char* fn, Digraph& digraph) 
   414       : _os(new std::ofstream(fn)), local_os(true), _digraph(digraph),
   415 	_skip_nodes(false), _skip_arcs(false) {}
   416 
   417     /// \brief Copy constructor
   418     ///
   419     /// The copy constructor transfers all data from the other writer,
   420     /// therefore the copied writer will not be usable more. 
   421     DigraphWriter(DigraphWriter& other) 
   422       : _os(other._os), local_os(other.local_os), _digraph(other._digraph),
   423 	_skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
   424 
   425       other._os = 0;
   426       other.local_os = false;
   427 
   428       _node_index.swap(other._node_index);
   429       _arc_index.swap(other._arc_index);
   430 
   431       _node_maps.swap(other._node_maps);
   432       _arc_maps.swap(other._arc_maps);
   433       _attributes.swap(other._attributes);
   434 
   435       _nodes_caption = other._nodes_caption;
   436       _arcs_caption = other._arcs_caption;
   437       _attributes_caption = other._attributes_caption;
   438     }
   439 
   440     /// \brief Destructor
   441     ~DigraphWriter() {
   442       for (typename NodeMaps::iterator it = _node_maps.begin(); 
   443 	   it != _node_maps.end(); ++it) {
   444 	delete it->second;
   445       }
   446 
   447       for (typename ArcMaps::iterator it = _arc_maps.begin(); 
   448 	   it != _arc_maps.end(); ++it) {
   449 	delete it->second;
   450       }
   451 
   452       for (typename Attributes::iterator it = _attributes.begin(); 
   453 	   it != _attributes.end(); ++it) {
   454 	delete it->second;
   455       }
   456 
   457       if (local_os) {
   458 	delete _os;
   459       }
   460     }
   461 
   462   private:
   463     
   464     DigraphWriter& operator=(const DigraphWriter&);
   465 
   466   public:
   467 
   468     /// \name Writing rules
   469     /// @{
   470     
   471     /// \brief Node map reading rule
   472     ///
   473     /// Add a node map reading rule to the writer.
   474     template <typename Map>
   475     DigraphWriter& nodeMap(const std::string& caption, const Map& map) {
   476       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
   477       _writer_bits::MapStorageBase<Node>* storage = 
   478 	new _writer_bits::MapStorage<Node, Map>(map);
   479       _node_maps.push_back(std::make_pair(caption, storage));
   480       return *this;
   481     }
   482 
   483     /// \brief Node map writing rule
   484     ///
   485     /// Add a node map writing rule with specialized converter to the
   486     /// writer.
   487     template <typename Map, typename Converter>
   488     DigraphWriter& nodeMap(const std::string& caption, const Map& map, 
   489 			   const Converter& converter = Converter()) {
   490       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
   491       _writer_bits::MapStorageBase<Node>* storage = 
   492 	new _writer_bits::MapStorage<Node, Map, Converter>(map, converter);
   493       _node_maps.push_back(std::make_pair(caption, storage));
   494       return *this;
   495     }
   496 
   497     /// \brief Arc map writing rule
   498     ///
   499     /// Add an arc map writing rule to the writer.
   500     template <typename Map>
   501     DigraphWriter& arcMap(const std::string& caption, const Map& map) {
   502       checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
   503       _writer_bits::MapStorageBase<Arc>* storage = 
   504 	new _writer_bits::MapStorage<Arc, Map>(map);
   505       _arc_maps.push_back(std::make_pair(caption, storage));
   506       return *this;
   507     }
   508 
   509     /// \brief Arc map writing rule
   510     ///
   511     /// Add an arc map writing rule with specialized converter to the
   512     /// writer.
   513     template <typename Map, typename Converter>
   514     DigraphWriter& arcMap(const std::string& caption, const Map& map, 
   515 			  const Converter& converter = Converter()) {
   516       checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
   517       _writer_bits::MapStorageBase<Arc>* storage = 
   518 	new _writer_bits::MapStorage<Arc, Map, Converter>(map, converter);
   519       _arc_maps.push_back(std::make_pair(caption, storage));
   520       return *this;
   521     }
   522 
   523     /// \brief Attribute writing rule
   524     ///
   525     /// Add an attribute writing rule to the writer.
   526     template <typename Value>
   527     DigraphWriter& attribute(const std::string& caption, const Value& value) {
   528       _writer_bits::ValueStorageBase* storage = 
   529 	new _writer_bits::ValueStorage<Value>(value);
   530       _attributes.push_back(std::make_pair(caption, storage));
   531       return *this;
   532     }
   533 
   534     /// \brief Attribute writing rule
   535     ///
   536     /// Add an attribute writing rule with specialized converter to the
   537     /// writer.
   538     template <typename Value, typename Converter>
   539     DigraphWriter& attribute(const std::string& caption, const Value& value, 
   540 			     const Converter& converter = Converter()) {
   541       _writer_bits::ValueStorageBase* storage = 
   542 	new _writer_bits::ValueStorage<Value, Converter>(value, converter);
   543       _attributes.push_back(std::make_pair(caption, storage));
   544       return *this;
   545     }
   546 
   547     /// \brief Node writing rule
   548     ///
   549     /// Add a node writing rule to the writer.
   550     DigraphWriter& node(const std::string& caption, const Node& node) {
   551       typedef _writer_bits::MapLookUpConverter<Node> Converter;
   552       Converter converter(_node_index);
   553       _writer_bits::ValueStorageBase* storage = 
   554 	new _writer_bits::ValueStorage<Node, Converter>(node, converter);
   555       _attributes.push_back(std::make_pair(caption, storage));
   556       return *this;
   557     }
   558 
   559     /// \brief Arc writing rule
   560     ///
   561     /// Add an arc writing rule to writer.
   562     DigraphWriter& arc(const std::string& caption, const Arc& arc) {
   563       typedef _writer_bits::MapLookUpConverter<Arc> Converter;
   564       Converter converter(_arc_index);
   565       _writer_bits::ValueStorageBase* storage = 
   566 	new _writer_bits::ValueStorage<Arc, Converter>(arc, converter);
   567       _attributes.push_back(std::make_pair(caption, storage));
   568       return *this;
   569     }
   570 
   571     /// \name Select section by name
   572     /// @{
   573 
   574     /// \brief Set \c \@nodes section to be read
   575     ///
   576     /// Set \c \@nodes section to be read
   577     DigraphWriter& nodes(const std::string& caption) {
   578       _nodes_caption = caption;
   579       return *this;
   580     }
   581 
   582     /// \brief Set \c \@arcs section to be read
   583     ///
   584     /// Set \c \@arcs section to be read
   585     DigraphWriter& arcs(const std::string& caption) {
   586       _arcs_caption = caption;
   587       return *this;
   588     }
   589 
   590     /// \brief Set \c \@attributes section to be read
   591     ///
   592     /// Set \c \@attributes section to be read
   593     DigraphWriter& attributes(const std::string& caption) {
   594       _attributes_caption = caption;
   595       return *this;
   596     }
   597 
   598     /// \name Skipping section
   599     /// @{
   600 
   601     /// \brief Skip writing the node set
   602     ///
   603     /// The \c \@nodes section will be not written to the stream.
   604     DigraphWriter& skipNodes() {
   605       LEMON_ASSERT(!_skip_nodes, "Multiple usage of skipNodes() member");
   606       return *this;
   607     }
   608 
   609     /// \brief Skip writing arc set
   610     ///
   611     /// The \c \@arcs section will be not written to the stream.
   612     DigraphWriter& skipArcs() {
   613       LEMON_ASSERT(!_skip_arcs, "Multiple usage of skipArcs() member");
   614       return *this;
   615     }
   616 
   617     /// @}
   618 
   619   private:
   620 
   621     void writeNodes() {
   622       _writer_bits::MapStorageBase<Node>* label = 0;
   623       for (typename NodeMaps::iterator it = _node_maps.begin();
   624 	   it != _node_maps.end(); ++it) {
   625         if (it->first == "label") {
   626 	  label = it->second;
   627 	  break;
   628 	}
   629       }
   630 
   631       *_os << "@nodes";
   632       if (!_nodes_caption.empty()) {
   633 	_writer_bits::writeToken(*_os << ' ', _nodes_caption);
   634       }
   635       *_os << std::endl;
   636 
   637       if (label == 0) {
   638 	*_os << "label" << '\t';
   639       }
   640       for (typename NodeMaps::iterator it = _node_maps.begin();
   641 	   it != _node_maps.end(); ++it) {
   642 	_writer_bits::writeToken(*_os, it->first) << '\t';
   643       }
   644       *_os << std::endl;
   645 
   646       std::vector<Node> nodes;
   647       for (NodeIt n(_digraph); n != INVALID; ++n) {
   648 	nodes.push_back(n);
   649       }
   650       
   651       if (label == 0) {
   652 	IdMap<Digraph, Node> id_map(_digraph);
   653 	_writer_bits::MapLess<IdMap<Digraph, Node> > id_less(id_map);
   654 	std::sort(nodes.begin(), nodes.end(), id_less);
   655       } else {
   656 	label->sort(nodes);
   657       }
   658 
   659       for (int i = 0; i < static_cast<int>(nodes.size()); ++i) {
   660 	Node n = nodes[i];
   661 	if (label == 0) {
   662 	  std::ostringstream os;
   663 	  os << _digraph.id(n);
   664 	  _writer_bits::writeToken(*_os, os.str());
   665 	  *_os << '\t';
   666 	  _node_index.insert(std::make_pair(n, os.str()));
   667 	}
   668 	for (typename NodeMaps::iterator it = _node_maps.begin();
   669 	     it != _node_maps.end(); ++it) {
   670 	  std::string value = it->second->get(n);
   671 	  _writer_bits::writeToken(*_os, value);
   672 	  if (it->first == "label") {
   673 	    _node_index.insert(std::make_pair(n, value));
   674 	  }
   675 	  *_os << '\t';
   676 	}
   677 	*_os << std::endl;
   678       }
   679     }
   680 
   681     void writeArcs() {
   682       _writer_bits::MapStorageBase<Arc>* label = 0;
   683       for (typename ArcMaps::iterator it = _arc_maps.begin();
   684 	   it != _arc_maps.end(); ++it) {
   685         if (it->first == "label") {
   686 	  label = it->second;
   687 	  break;
   688 	}
   689       }
   690 
   691       *_os << "@arcs";
   692       if (!_arcs_caption.empty()) {
   693 	_writer_bits::writeToken(*_os << ' ', _arcs_caption);
   694       }
   695       *_os << std::endl;
   696 
   697       *_os << '\t' << '\t';
   698       if (label == 0) {
   699 	*_os << "label" << '\t';
   700       }
   701       for (typename ArcMaps::iterator it = _arc_maps.begin();
   702 	   it != _arc_maps.end(); ++it) {
   703 	_writer_bits::writeToken(*_os, it->first) << '\t';
   704       }
   705       *_os << std::endl;
   706 
   707       std::vector<Arc> arcs;
   708       for (ArcIt n(_digraph); n != INVALID; ++n) {
   709 	arcs.push_back(n);
   710       }
   711       
   712       if (label == 0) {
   713 	IdMap<Digraph, Arc> id_map(_digraph);
   714 	_writer_bits::MapLess<IdMap<Digraph, Arc> > id_less(id_map);
   715 	std::sort(arcs.begin(), arcs.end(), id_less);
   716       } else {
   717 	label->sort(arcs);
   718       }
   719 
   720       for (int i = 0; i < static_cast<int>(arcs.size()); ++i) {
   721 	Arc a = arcs[i];
   722 	_writer_bits::writeToken(*_os, _node_index.
   723 				 find(_digraph.source(a))->second);
   724 	*_os << '\t';
   725 	_writer_bits::writeToken(*_os, _node_index.
   726 				 find(_digraph.target(a))->second);
   727 	*_os << '\t';
   728 	if (label == 0) {
   729 	  std::ostringstream os;
   730 	  os << _digraph.id(a);
   731 	  _writer_bits::writeToken(*_os, os.str());
   732 	  *_os << '\t';
   733 	  _arc_index.insert(std::make_pair(a, os.str()));
   734 	}
   735 	for (typename ArcMaps::iterator it = _arc_maps.begin();
   736 	     it != _arc_maps.end(); ++it) {
   737 	  std::string value = it->second->get(a);
   738 	  _writer_bits::writeToken(*_os, value);
   739 	  if (it->first == "label") {
   740 	    _arc_index.insert(std::make_pair(a, value));
   741 	  }
   742 	  *_os << '\t';
   743 	}
   744 	*_os << std::endl;
   745       }
   746     }
   747 
   748     void writeAttributes() {
   749       if (_attributes.empty()) return;
   750       *_os << "@attributes";
   751       if (!_attributes_caption.empty()) {
   752 	_writer_bits::writeToken(*_os << ' ', _attributes_caption);
   753       }
   754       *_os << std::endl;
   755       for (typename Attributes::iterator it = _attributes.begin();
   756 	   it != _attributes.end(); ++it) {
   757 	_writer_bits::writeToken(*_os, it->first) << ' ';
   758 	_writer_bits::writeToken(*_os, it->second->get());
   759 	*_os << std::endl;
   760       }
   761     }
   762     
   763   public:
   764     
   765     /// \name Execution of the writer    
   766     /// @{
   767 
   768     /// \brief Start the batch processing
   769     ///
   770     /// This function starts the batch processing
   771     void run() {
   772       if (!_skip_nodes) {
   773 	writeNodes();
   774       }
   775       if (!_skip_arcs) {      
   776 	writeArcs();
   777       }
   778       writeAttributes();
   779     }
   780 
   781     /// \brief Gives back the stream of the writer
   782     ///
   783     /// Gives back the stream of the writer
   784     std::ostream& ostream() {
   785       return *_os;
   786     }
   787 
   788     /// @}
   789   };
   790 
   791   /// \relates DigraphWriter
   792   template <typename Digraph>
   793   DigraphWriter<Digraph> digraphWriter(std::ostream& os, Digraph& digraph) {
   794     DigraphWriter<Digraph> tmp(os, digraph);
   795     return tmp;
   796   }
   797 
   798   /// \relates DigraphWriter
   799   template <typename Digraph>
   800   DigraphWriter<Digraph> digraphWriter(const std::string& fn, 
   801 				       Digraph& digraph) {
   802     DigraphWriter<Digraph> tmp(fn, digraph);
   803     return tmp;
   804   }
   805 
   806   /// \relates DigraphWriter
   807   template <typename Digraph>
   808   DigraphWriter<Digraph> digraphWriter(const char* fn, Digraph& digraph) {
   809     DigraphWriter<Digraph> tmp(fn, digraph);
   810     return tmp;
   811   }
   812 
   813   /// \ingroup lemon_io
   814   ///  
   815   /// \brief LGF writer for directed graphs
   816   ///
   817   /// This utility writes an \ref lgf-format "LGF" file.
   818   template <typename _Graph>
   819   class GraphWriter {
   820   public:
   821 
   822     typedef _Graph Graph;
   823     TEMPLATE_GRAPH_TYPEDEFS(Graph);
   824     
   825   private:
   826 
   827 
   828     std::ostream* _os;
   829     bool local_os;
   830 
   831     Graph& _graph;
   832 
   833     std::string _nodes_caption;
   834     std::string _edges_caption;
   835     std::string _attributes_caption;
   836     
   837     typedef std::map<Node, std::string> NodeIndex;
   838     NodeIndex _node_index;
   839     typedef std::map<Edge, std::string> EdgeIndex;
   840     EdgeIndex _edge_index;
   841 
   842     typedef std::vector<std::pair<std::string, 
   843       _writer_bits::MapStorageBase<Node>* > > NodeMaps;    
   844     NodeMaps _node_maps; 
   845 
   846     typedef std::vector<std::pair<std::string, 
   847       _writer_bits::MapStorageBase<Edge>* > >EdgeMaps;
   848     EdgeMaps _edge_maps;
   849 
   850     typedef std::vector<std::pair<std::string, 
   851       _writer_bits::ValueStorageBase*> > Attributes;
   852     Attributes _attributes;
   853 
   854     bool _skip_nodes;
   855     bool _skip_edges;
   856 
   857   public:
   858 
   859     /// \brief Constructor
   860     ///
   861     /// Construct a directed graph writer, which writes to the given
   862     /// output stream.
   863     GraphWriter(std::ostream& is, Graph& graph) 
   864       : _os(&is), local_os(false), _graph(graph),
   865 	_skip_nodes(false), _skip_edges(false) {}
   866 
   867     /// \brief Constructor
   868     ///
   869     /// Construct a directed graph writer, which writes to the given
   870     /// output file.
   871     GraphWriter(const std::string& fn, Graph& graph) 
   872       : _os(new std::ofstream(fn.c_str())), local_os(true), _graph(graph),
   873 	_skip_nodes(false), _skip_edges(false) {}
   874 
   875     /// \brief Constructor
   876     ///
   877     /// Construct a directed graph writer, which writes to the given
   878     /// output file.
   879     GraphWriter(const char* fn, Graph& graph) 
   880       : _os(new std::ofstream(fn)), local_os(true), _graph(graph),
   881 	_skip_nodes(false), _skip_edges(false) {}
   882 
   883     /// \brief Copy constructor
   884     ///
   885     /// The copy constructor transfers all data from the other writer,
   886     /// therefore the copied writer will not be usable more. 
   887     GraphWriter(GraphWriter& other) 
   888       : _os(other._os), local_os(other.local_os), _graph(other._graph),
   889 	_skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
   890 
   891       other._os = 0;
   892       other.local_os = false;
   893 
   894       _node_index.swap(other._node_index);
   895       _edge_index.swap(other._edge_index);
   896 
   897       _node_maps.swap(other._node_maps);
   898       _edge_maps.swap(other._edge_maps);
   899       _attributes.swap(other._attributes);
   900 
   901       _nodes_caption = other._nodes_caption;
   902       _edges_caption = other._edges_caption;
   903       _attributes_caption = other._attributes_caption;
   904     }
   905 
   906     /// \brief Destructor
   907     ~GraphWriter() {
   908       for (typename NodeMaps::iterator it = _node_maps.begin(); 
   909 	   it != _node_maps.end(); ++it) {
   910 	delete it->second;
   911       }
   912 
   913       for (typename EdgeMaps::iterator it = _edge_maps.begin(); 
   914 	   it != _edge_maps.end(); ++it) {
   915 	delete it->second;
   916       }
   917 
   918       for (typename Attributes::iterator it = _attributes.begin(); 
   919 	   it != _attributes.end(); ++it) {
   920 	delete it->second;
   921       }
   922 
   923       if (local_os) {
   924 	delete _os;
   925       }
   926     }
   927 
   928   private:
   929     
   930     GraphWriter& operator=(const GraphWriter&);
   931 
   932   public:
   933 
   934     /// \name Writing rules
   935     /// @{
   936     
   937     /// \brief Node map reading rule
   938     ///
   939     /// Add a node map reading rule to the writer.
   940     template <typename Map>
   941     GraphWriter& nodeMap(const std::string& caption, const Map& map) {
   942       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
   943       _writer_bits::MapStorageBase<Node>* storage = 
   944 	new _writer_bits::MapStorage<Node, Map>(map);
   945       _node_maps.push_back(std::make_pair(caption, storage));
   946       return *this;
   947     }
   948 
   949     /// \brief Node map writing rule
   950     ///
   951     /// Add a node map writing rule with specialized converter to the
   952     /// writer.
   953     template <typename Map, typename Converter>
   954     GraphWriter& nodeMap(const std::string& caption, const Map& map, 
   955 			   const Converter& converter = Converter()) {
   956       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
   957       _writer_bits::MapStorageBase<Node>* storage = 
   958 	new _writer_bits::MapStorage<Node, Map, Converter>(map, converter);
   959       _node_maps.push_back(std::make_pair(caption, storage));
   960       return *this;
   961     }
   962 
   963     /// \brief Edge map writing rule
   964     ///
   965     /// Add an edge map writing rule to the writer.
   966     template <typename Map>
   967     GraphWriter& edgeMap(const std::string& caption, const Map& map) {
   968       checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
   969       _writer_bits::MapStorageBase<Edge>* storage = 
   970 	new _writer_bits::MapStorage<Edge, Map>(map);
   971       _edge_maps.push_back(std::make_pair(caption, storage));
   972       return *this;
   973     }
   974 
   975     /// \brief Edge map writing rule
   976     ///
   977     /// Add an edge map writing rule with specialized converter to the
   978     /// writer.
   979     template <typename Map, typename Converter>
   980     GraphWriter& edgeMap(const std::string& caption, const Map& map, 
   981 			  const Converter& converter = Converter()) {
   982       checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
   983       _writer_bits::MapStorageBase<Edge>* storage = 
   984 	new _writer_bits::MapStorage<Edge, Map, Converter>(map, converter);
   985       _edge_maps.push_back(std::make_pair(caption, storage));
   986       return *this;
   987     }
   988 
   989     /// \brief Arc map writing rule
   990     ///
   991     /// Add an arc map writing rule to the writer.
   992     template <typename Map>
   993     GraphWriter& arcMap(const std::string& caption, const Map& map) {
   994       checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
   995       _writer_bits::MapStorageBase<Edge>* forward_storage = 
   996 	new _writer_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
   997       _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
   998       _writer_bits::MapStorageBase<Edge>* backward_storage = 
   999 	new _writer_bits::GraphArcMapStorage<Graph, false, Map>(_graph, map);
  1000       _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
  1001       return *this;
  1002     }
  1003 
  1004     /// \brief Arc map writing rule
  1005     ///
  1006     /// Add an arc map writing rule with specialized converter to the
  1007     /// writer.
  1008     template <typename Map, typename Converter>
  1009     GraphWriter& arcMap(const std::string& caption, const Map& map, 
  1010 			  const Converter& converter = Converter()) {
  1011       checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
  1012       _writer_bits::MapStorageBase<Edge>* forward_storage = 
  1013 	new _writer_bits::GraphArcMapStorage<Graph, true, Map, Converter>
  1014 	(_graph, map, converter);
  1015       _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
  1016       _writer_bits::MapStorageBase<Edge>* backward_storage = 
  1017 	new _writer_bits::GraphArcMapStorage<Graph, false, Map, Converter>
  1018 	(_graph, map, converter);
  1019       _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
  1020       return *this;
  1021     }
  1022 
  1023     /// \brief Attribute writing rule
  1024     ///
  1025     /// Add an attribute writing rule to the writer.
  1026     template <typename Value>
  1027     GraphWriter& attribute(const std::string& caption, const Value& value) {
  1028       _writer_bits::ValueStorageBase* storage = 
  1029 	new _writer_bits::ValueStorage<Value>(value);
  1030       _attributes.push_back(std::make_pair(caption, storage));
  1031       return *this;
  1032     }
  1033 
  1034     /// \brief Attribute writing rule
  1035     ///
  1036     /// Add an attribute writing rule with specialized converter to the
  1037     /// writer.
  1038     template <typename Value, typename Converter>
  1039     GraphWriter& attribute(const std::string& caption, const Value& value, 
  1040 			     const Converter& converter = Converter()) {
  1041       _writer_bits::ValueStorageBase* storage = 
  1042 	new _writer_bits::ValueStorage<Value, Converter>(value, converter);
  1043       _attributes.push_back(std::make_pair(caption, storage));
  1044       return *this;
  1045     }
  1046 
  1047     /// \brief Node writing rule
  1048     ///
  1049     /// Add a node writing rule to the writer.
  1050     GraphWriter& node(const std::string& caption, const Node& node) {
  1051       typedef _writer_bits::MapLookUpConverter<Node> Converter;
  1052       Converter converter(_node_index);
  1053       _writer_bits::ValueStorageBase* storage = 
  1054 	new _writer_bits::ValueStorage<Node, Converter>(node, converter);
  1055       _attributes.push_back(std::make_pair(caption, storage));
  1056       return *this;
  1057     }
  1058 
  1059     /// \brief Edge writing rule
  1060     ///
  1061     /// Add an edge writing rule to writer.
  1062     GraphWriter& edge(const std::string& caption, const Edge& edge) {
  1063       typedef _writer_bits::MapLookUpConverter<Edge> Converter;
  1064       Converter converter(_edge_index);
  1065       _writer_bits::ValueStorageBase* storage = 
  1066 	new _writer_bits::ValueStorage<Edge, Converter>(edge, converter);
  1067       _attributes.push_back(std::make_pair(caption, storage));
  1068       return *this;
  1069     }
  1070 
  1071     /// \brief Arc writing rule
  1072     ///
  1073     /// Add an arc writing rule to writer.
  1074     GraphWriter& arc(const std::string& caption, const Arc& arc) {
  1075       typedef _writer_bits::GraphArcLookUpConverter<Graph> Converter;
  1076       Converter converter(_graph, _edge_index);
  1077       _writer_bits::ValueStorageBase* storage = 
  1078 	new _writer_bits::ValueStorage<Arc, Converter>(arc, converter);
  1079       _attributes.push_back(std::make_pair(caption, storage));
  1080       return *this;
  1081     }
  1082 
  1083     /// \name Select section by name
  1084     /// @{
  1085 
  1086     /// \brief Set \c \@nodes section to be read
  1087     ///
  1088     /// Set \c \@nodes section to be read
  1089     GraphWriter& nodes(const std::string& caption) {
  1090       _nodes_caption = caption;
  1091       return *this;
  1092     }
  1093 
  1094     /// \brief Set \c \@edges section to be read
  1095     ///
  1096     /// Set \c \@edges section to be read
  1097     GraphWriter& edges(const std::string& caption) {
  1098       _edges_caption = caption;
  1099       return *this;
  1100     }
  1101 
  1102     /// \brief Set \c \@attributes section to be read
  1103     ///
  1104     /// Set \c \@attributes section to be read
  1105     GraphWriter& attributes(const std::string& caption) {
  1106       _attributes_caption = caption;
  1107       return *this;
  1108     }
  1109 
  1110     /// \name Skipping section
  1111     /// @{
  1112 
  1113     /// \brief Skip writing the node set
  1114     ///
  1115     /// The \c \@nodes section will be not written to the stream.
  1116     GraphWriter& skipNodes() {
  1117       LEMON_ASSERT(!_skip_nodes, "Multiple usage of skipNodes() member");
  1118       return *this;
  1119     }
  1120 
  1121     /// \brief Skip writing edge set
  1122     ///
  1123     /// The \c \@edges section will be not written to the stream.
  1124     GraphWriter& skipEdges() {
  1125       LEMON_ASSERT(!_skip_edges, "Multiple usage of skipEdges() member");
  1126       return *this;
  1127     }
  1128 
  1129     /// @}
  1130 
  1131   private:
  1132 
  1133     void writeNodes() {
  1134       _writer_bits::MapStorageBase<Node>* label = 0;
  1135       for (typename NodeMaps::iterator it = _node_maps.begin();
  1136 	   it != _node_maps.end(); ++it) {
  1137         if (it->first == "label") {
  1138 	  label = it->second;
  1139 	  break;
  1140 	}
  1141       }
  1142 
  1143       *_os << "@nodes";
  1144       if (!_nodes_caption.empty()) {
  1145 	_writer_bits::writeToken(*_os << ' ', _nodes_caption);
  1146       }
  1147       *_os << std::endl;
  1148 
  1149       if (label == 0) {
  1150 	*_os << "label" << '\t';
  1151       }
  1152       for (typename NodeMaps::iterator it = _node_maps.begin();
  1153 	   it != _node_maps.end(); ++it) {
  1154 	_writer_bits::writeToken(*_os, it->first) << '\t';
  1155       }
  1156       *_os << std::endl;
  1157 
  1158       std::vector<Node> nodes;
  1159       for (NodeIt n(_graph); n != INVALID; ++n) {
  1160 	nodes.push_back(n);
  1161       }
  1162       
  1163       if (label == 0) {
  1164 	IdMap<Graph, Node> id_map(_graph);
  1165 	_writer_bits::MapLess<IdMap<Graph, Node> > id_less(id_map);
  1166 	std::sort(nodes.begin(), nodes.end(), id_less);
  1167       } else {
  1168 	label->sort(nodes);
  1169       }
  1170 
  1171       for (int i = 0; i < static_cast<int>(nodes.size()); ++i) {
  1172 	Node n = nodes[i];
  1173 	if (label == 0) {
  1174 	  std::ostringstream os;
  1175 	  os << _graph.id(n);
  1176 	  _writer_bits::writeToken(*_os, os.str());
  1177 	  *_os << '\t';
  1178 	  _node_index.insert(std::make_pair(n, os.str()));
  1179 	}
  1180 	for (typename NodeMaps::iterator it = _node_maps.begin();
  1181 	     it != _node_maps.end(); ++it) {
  1182 	  std::string value = it->second->get(n);
  1183 	  _writer_bits::writeToken(*_os, value);
  1184 	  if (it->first == "label") {
  1185 	    _node_index.insert(std::make_pair(n, value));
  1186 	  }
  1187 	  *_os << '\t';
  1188 	}
  1189 	*_os << std::endl;
  1190       }
  1191     }
  1192 
  1193     void writeEdges() {
  1194       _writer_bits::MapStorageBase<Edge>* label = 0;
  1195       for (typename EdgeMaps::iterator it = _edge_maps.begin();
  1196 	   it != _edge_maps.end(); ++it) {
  1197         if (it->first == "label") {
  1198 	  label = it->second;
  1199 	  break;
  1200 	}
  1201       }
  1202 
  1203       *_os << "@edges";
  1204       if (!_edges_caption.empty()) {
  1205 	_writer_bits::writeToken(*_os << ' ', _edges_caption);
  1206       }
  1207       *_os << std::endl;
  1208 
  1209       *_os << '\t' << '\t';
  1210       if (label == 0) {
  1211 	*_os << "label" << '\t';
  1212       }
  1213       for (typename EdgeMaps::iterator it = _edge_maps.begin();
  1214 	   it != _edge_maps.end(); ++it) {
  1215 	_writer_bits::writeToken(*_os, it->first) << '\t';
  1216       }
  1217       *_os << std::endl;
  1218 
  1219       std::vector<Edge> edges;
  1220       for (EdgeIt n(_graph); n != INVALID; ++n) {
  1221 	edges.push_back(n);
  1222       }
  1223       
  1224       if (label == 0) {
  1225 	IdMap<Graph, Edge> id_map(_graph);
  1226 	_writer_bits::MapLess<IdMap<Graph, Edge> > id_less(id_map);
  1227 	std::sort(edges.begin(), edges.end(), id_less);
  1228       } else {
  1229 	label->sort(edges);
  1230       }
  1231 
  1232       for (int i = 0; i < static_cast<int>(edges.size()); ++i) {
  1233 	Edge e = edges[i];
  1234 	_writer_bits::writeToken(*_os, _node_index.
  1235 				 find(_graph.u(e))->second);
  1236 	*_os << '\t';
  1237 	_writer_bits::writeToken(*_os, _node_index.
  1238 				 find(_graph.v(e))->second);
  1239 	*_os << '\t';
  1240 	if (label == 0) {
  1241 	  std::ostringstream os;
  1242 	  os << _graph.id(e);
  1243 	  _writer_bits::writeToken(*_os, os.str());
  1244 	  *_os << '\t';
  1245 	  _edge_index.insert(std::make_pair(e, os.str()));
  1246 	}
  1247 	for (typename EdgeMaps::iterator it = _edge_maps.begin();
  1248 	     it != _edge_maps.end(); ++it) {
  1249 	  std::string value = it->second->get(e);
  1250 	  _writer_bits::writeToken(*_os, value);
  1251 	  if (it->first == "label") {
  1252 	    _edge_index.insert(std::make_pair(e, value));
  1253 	  }
  1254 	  *_os << '\t';
  1255 	}
  1256 	*_os << std::endl;
  1257       }
  1258     }
  1259 
  1260     void writeAttributes() {
  1261       if (_attributes.empty()) return;
  1262       *_os << "@attributes";
  1263       if (!_attributes_caption.empty()) {
  1264 	_writer_bits::writeToken(*_os << ' ', _attributes_caption);
  1265       }
  1266       *_os << std::endl;
  1267       for (typename Attributes::iterator it = _attributes.begin();
  1268 	   it != _attributes.end(); ++it) {
  1269 	_writer_bits::writeToken(*_os, it->first) << ' ';
  1270 	_writer_bits::writeToken(*_os, it->second->get());
  1271 	*_os << std::endl;
  1272       }
  1273     }
  1274     
  1275   public:
  1276     
  1277     /// \name Execution of the writer    
  1278     /// @{
  1279 
  1280     /// \brief Start the batch processing
  1281     ///
  1282     /// This function starts the batch processing
  1283     void run() {
  1284       if (!_skip_nodes) {
  1285 	writeNodes();
  1286       }
  1287       if (!_skip_edges) {      
  1288 	writeEdges();
  1289       }
  1290       writeAttributes();
  1291     }
  1292 
  1293     /// \brief Gives back the stream of the writer
  1294     ///
  1295     /// Gives back the stream of the writer
  1296     std::ostream& ostream() {
  1297       return *_os;
  1298     }
  1299 
  1300     /// @}
  1301   };
  1302 
  1303   /// \relates GraphWriter
  1304   template <typename Graph>
  1305   GraphWriter<Graph> graphWriter(std::ostream& os, Graph& graph) {
  1306     GraphWriter<Graph> tmp(os, graph);
  1307     return tmp;
  1308   }
  1309 
  1310   /// \relates GraphWriter
  1311   template <typename Graph>
  1312   GraphWriter<Graph> graphWriter(const std::string& fn, Graph& graph) {
  1313     GraphWriter<Graph> tmp(fn, graph);
  1314     return tmp;
  1315   }
  1316 
  1317   /// \relates GraphWriter
  1318   template <typename Graph>
  1319   GraphWriter<Graph> graphWriter(const char* fn, Graph& graph) {
  1320     GraphWriter<Graph> tmp(fn, graph);
  1321     return tmp;
  1322   }
  1323 }
  1324 
  1325 #endif