lemon/lgf_reader.h
author Alpar Juttner <alpar@cs.elte.hu>
Mon, 23 Feb 2009 15:46:57 +0000
changeset 379 39aaeea2d471
parent 327 5e12d7734036
child 376 d3524090d5e2
child 422 54464584b157
permissions -rw-r--r--
Include /lemon/config.h globally (#230)
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     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 \ref lgf-format "LEMON Graph Format" reader.
    22 
    23 
    24 #ifndef LEMON_LGF_READER_H
    25 #define LEMON_LGF_READER_H
    26 
    27 #include <iostream>
    28 #include <fstream>
    29 #include <sstream>
    30 
    31 #include <set>
    32 #include <map>
    33 
    34 #include <lemon/core.h>
    35 
    36 #include <lemon/lgf_writer.h>
    37 
    38 #include <lemon/concept_check.h>
    39 #include <lemon/concepts/maps.h>
    40 
    41 namespace lemon {
    42 
    43   namespace _reader_bits {
    44 
    45     template <typename Value>
    46     struct DefaultConverter {
    47       Value operator()(const std::string& str) {
    48         std::istringstream is(str);
    49         Value value;
    50         if (!(is >> value)) {
    51           throw FormatError("Cannot read token");
    52         }
    53 
    54         char c;
    55         if (is >> std::ws >> c) {
    56           throw FormatError("Remaining characters in token");
    57         }
    58         return value;
    59       }
    60     };
    61 
    62     template <>
    63     struct DefaultConverter<std::string> {
    64       std::string operator()(const std::string& str) {
    65         return str;
    66       }
    67     };
    68 
    69     template <typename _Item>
    70     class MapStorageBase {
    71     public:
    72       typedef _Item Item;
    73 
    74     public:
    75       MapStorageBase() {}
    76       virtual ~MapStorageBase() {}
    77 
    78       virtual void set(const Item& item, const std::string& value) = 0;
    79 
    80     };
    81 
    82     template <typename _Item, typename _Map,
    83               typename _Converter = DefaultConverter<typename _Map::Value> >
    84     class MapStorage : public MapStorageBase<_Item> {
    85     public:
    86       typedef _Map Map;
    87       typedef _Converter Converter;
    88       typedef _Item Item;
    89 
    90     private:
    91       Map& _map;
    92       Converter _converter;
    93 
    94     public:
    95       MapStorage(Map& map, const Converter& converter = Converter())
    96         : _map(map), _converter(converter) {}
    97       virtual ~MapStorage() {}
    98 
    99       virtual void set(const Item& item ,const std::string& value) {
   100         _map.set(item, _converter(value));
   101       }
   102     };
   103 
   104     template <typename _Graph, bool _dir, typename _Map,
   105               typename _Converter = DefaultConverter<typename _Map::Value> >
   106     class GraphArcMapStorage : public MapStorageBase<typename _Graph::Edge> {
   107     public:
   108       typedef _Map Map;
   109       typedef _Converter Converter;
   110       typedef _Graph Graph;
   111       typedef typename Graph::Edge Item;
   112       static const bool dir = _dir;
   113 
   114     private:
   115       const Graph& _graph;
   116       Map& _map;
   117       Converter _converter;
   118 
   119     public:
   120       GraphArcMapStorage(const Graph& graph, Map& map,
   121                          const Converter& converter = Converter())
   122         : _graph(graph), _map(map), _converter(converter) {}
   123       virtual ~GraphArcMapStorage() {}
   124 
   125       virtual void set(const Item& item ,const std::string& value) {
   126         _map.set(_graph.direct(item, dir), _converter(value));
   127       }
   128     };
   129 
   130     class ValueStorageBase {
   131     public:
   132       ValueStorageBase() {}
   133       virtual ~ValueStorageBase() {}
   134 
   135       virtual void set(const std::string&) = 0;
   136     };
   137 
   138     template <typename _Value, typename _Converter = DefaultConverter<_Value> >
   139     class ValueStorage : public ValueStorageBase {
   140     public:
   141       typedef _Value Value;
   142       typedef _Converter Converter;
   143 
   144     private:
   145       Value& _value;
   146       Converter _converter;
   147 
   148     public:
   149       ValueStorage(Value& value, const Converter& converter = Converter())
   150         : _value(value), _converter(converter) {}
   151 
   152       virtual void set(const std::string& value) {
   153         _value = _converter(value);
   154       }
   155     };
   156 
   157     template <typename Value>
   158     struct MapLookUpConverter {
   159       const std::map<std::string, Value>& _map;
   160 
   161       MapLookUpConverter(const std::map<std::string, Value>& map)
   162         : _map(map) {}
   163 
   164       Value operator()(const std::string& str) {
   165         typename std::map<std::string, Value>::const_iterator it =
   166           _map.find(str);
   167         if (it == _map.end()) {
   168           std::ostringstream msg;
   169           msg << "Item not found: " << str;
   170           throw FormatError(msg.str());
   171         }
   172         return it->second;
   173       }
   174     };
   175 
   176     template <typename Graph>
   177     struct GraphArcLookUpConverter {
   178       const Graph& _graph;
   179       const std::map<std::string, typename Graph::Edge>& _map;
   180 
   181       GraphArcLookUpConverter(const Graph& graph,
   182                               const std::map<std::string,
   183                                              typename Graph::Edge>& map)
   184         : _graph(graph), _map(map) {}
   185 
   186       typename Graph::Arc operator()(const std::string& str) {
   187         if (str.empty() || (str[0] != '+' && str[0] != '-')) {
   188           throw FormatError("Item must start with '+' or '-'");
   189         }
   190         typename std::map<std::string, typename Graph::Edge>
   191           ::const_iterator it = _map.find(str.substr(1));
   192         if (it == _map.end()) {
   193           throw FormatError("Item not found");
   194         }
   195         return _graph.direct(it->second, str[0] == '+');
   196       }
   197     };
   198 
   199     inline bool isWhiteSpace(char c) {
   200       return c == ' ' || c == '\t' || c == '\v' ||
   201         c == '\n' || c == '\r' || c == '\f';
   202     }
   203 
   204     inline bool isOct(char c) {
   205       return '0' <= c && c <='7';
   206     }
   207 
   208     inline int valueOct(char c) {
   209       LEMON_ASSERT(isOct(c), "The character is not octal.");
   210       return c - '0';
   211     }
   212 
   213     inline bool isHex(char c) {
   214       return ('0' <= c && c <= '9') ||
   215         ('a' <= c && c <= 'z') ||
   216         ('A' <= c && c <= 'Z');
   217     }
   218 
   219     inline int valueHex(char c) {
   220       LEMON_ASSERT(isHex(c), "The character is not hexadecimal.");
   221       if ('0' <= c && c <= '9') return c - '0';
   222       if ('a' <= c && c <= 'z') return c - 'a' + 10;
   223       return c - 'A' + 10;
   224     }
   225 
   226     inline bool isIdentifierFirstChar(char c) {
   227       return ('a' <= c && c <= 'z') ||
   228         ('A' <= c && c <= 'Z') || c == '_';
   229     }
   230 
   231     inline bool isIdentifierChar(char c) {
   232       return isIdentifierFirstChar(c) ||
   233         ('0' <= c && c <= '9');
   234     }
   235 
   236     inline char readEscape(std::istream& is) {
   237       char c;
   238       if (!is.get(c))
   239         throw FormatError("Escape format error");
   240 
   241       switch (c) {
   242       case '\\':
   243         return '\\';
   244       case '\"':
   245         return '\"';
   246       case '\'':
   247         return '\'';
   248       case '\?':
   249         return '\?';
   250       case 'a':
   251         return '\a';
   252       case 'b':
   253         return '\b';
   254       case 'f':
   255         return '\f';
   256       case 'n':
   257         return '\n';
   258       case 'r':
   259         return '\r';
   260       case 't':
   261         return '\t';
   262       case 'v':
   263         return '\v';
   264       case 'x':
   265         {
   266           int code;
   267           if (!is.get(c) || !isHex(c))
   268             throw FormatError("Escape format error");
   269           else if (code = valueHex(c), !is.get(c) || !isHex(c)) is.putback(c);
   270           else code = code * 16 + valueHex(c);
   271           return code;
   272         }
   273       default:
   274         {
   275           int code;
   276           if (!isOct(c))
   277             throw FormatError("Escape format error");
   278           else if (code = valueOct(c), !is.get(c) || !isOct(c))
   279             is.putback(c);
   280           else if (code = code * 8 + valueOct(c), !is.get(c) || !isOct(c))
   281             is.putback(c);
   282           else code = code * 8 + valueOct(c);
   283           return code;
   284         }
   285       }
   286     }
   287 
   288     inline std::istream& readToken(std::istream& is, std::string& str) {
   289       std::ostringstream os;
   290 
   291       char c;
   292       is >> std::ws;
   293 
   294       if (!is.get(c))
   295         return is;
   296 
   297       if (c == '\"') {
   298         while (is.get(c) && c != '\"') {
   299           if (c == '\\')
   300             c = readEscape(is);
   301           os << c;
   302         }
   303         if (!is)
   304           throw FormatError("Quoted format error");
   305       } else {
   306         is.putback(c);
   307         while (is.get(c) && !isWhiteSpace(c)) {
   308           if (c == '\\')
   309             c = readEscape(is);
   310           os << c;
   311         }
   312         if (!is) {
   313           is.clear();
   314         } else {
   315           is.putback(c);
   316         }
   317       }
   318       str = os.str();
   319       return is;
   320     }
   321 
   322     class Section {
   323     public:
   324       virtual ~Section() {}
   325       virtual void process(std::istream& is, int& line_num) = 0;
   326     };
   327 
   328     template <typename Functor>
   329     class LineSection : public Section {
   330     private:
   331 
   332       Functor _functor;
   333 
   334     public:
   335 
   336       LineSection(const Functor& functor) : _functor(functor) {}
   337       virtual ~LineSection() {}
   338 
   339       virtual void process(std::istream& is, int& line_num) {
   340         char c;
   341         std::string line;
   342         while (is.get(c) && c != '@') {
   343           if (c == '\n') {
   344             ++line_num;
   345           } else if (c == '#') {
   346             getline(is, line);
   347             ++line_num;
   348           } else if (!isWhiteSpace(c)) {
   349             is.putback(c);
   350             getline(is, line);
   351             _functor(line);
   352             ++line_num;
   353           }
   354         }
   355         if (is) is.putback(c);
   356         else if (is.eof()) is.clear();
   357       }
   358     };
   359 
   360     template <typename Functor>
   361     class StreamSection : public Section {
   362     private:
   363 
   364       Functor _functor;
   365 
   366     public:
   367 
   368       StreamSection(const Functor& functor) : _functor(functor) {}
   369       virtual ~StreamSection() {}
   370 
   371       virtual void process(std::istream& is, int& line_num) {
   372         _functor(is, line_num);
   373         char c;
   374         std::string line;
   375         while (is.get(c) && c != '@') {
   376           if (c == '\n') {
   377             ++line_num;
   378           } else if (!isWhiteSpace(c)) {
   379             getline(is, line);
   380             ++line_num;
   381           }
   382         }
   383         if (is) is.putback(c);
   384         else if (is.eof()) is.clear();
   385       }
   386     };
   387 
   388   }
   389 
   390   template <typename Digraph>
   391   class DigraphReader;
   392 
   393   template <typename Digraph>
   394   DigraphReader<Digraph> digraphReader(Digraph& digraph, 
   395                                        std::istream& is = std::cin);
   396   template <typename Digraph>
   397   DigraphReader<Digraph> digraphReader(Digraph& digraph, const std::string& fn);
   398   template <typename Digraph>
   399   DigraphReader<Digraph> digraphReader(Digraph& digraph, const char *fn);
   400 
   401   /// \ingroup lemon_io
   402   ///
   403   /// \brief \ref lgf-format "LGF" reader for directed graphs
   404   ///
   405   /// This utility reads an \ref lgf-format "LGF" file.
   406   ///
   407   /// The reading method does a batch processing. The user creates a
   408   /// reader object, then various reading rules can be added to the
   409   /// reader, and eventually the reading is executed with the \c run()
   410   /// member function. A map reading rule can be added to the reader
   411   /// with the \c nodeMap() or \c arcMap() members. An optional
   412   /// converter parameter can also be added as a standard functor
   413   /// converting from \c std::string to the value type of the map. If it
   414   /// is set, it will determine how the tokens in the file should be
   415   /// converted to the value type of the map. If the functor is not set,
   416   /// then a default conversion will be used. One map can be read into
   417   /// multiple map objects at the same time. The \c attribute(), \c
   418   /// node() and \c arc() functions are used to add attribute reading
   419   /// rules.
   420   ///
   421   ///\code
   422   /// DigraphReader<Digraph>(digraph, std::cin).
   423   ///   nodeMap("coordinates", coord_map).
   424   ///   arcMap("capacity", cap_map).
   425   ///   node("source", src).
   426   ///   node("target", trg).
   427   ///   attribute("caption", caption).
   428   ///   run();
   429   ///\endcode
   430   ///
   431   /// By default the reader uses the first section in the file of the
   432   /// proper type. If a section has an optional name, then it can be
   433   /// selected for reading by giving an optional name parameter to the
   434   /// \c nodes(), \c arcs() or \c attributes() functions.
   435   ///
   436   /// The \c useNodes() and \c useArcs() functions are used to tell the reader
   437   /// that the nodes or arcs should not be constructed (added to the
   438   /// graph) during the reading, but instead the label map of the items
   439   /// are given as a parameter of these functions. An
   440   /// application of these functions is multipass reading, which is
   441   /// important if two \c \@arcs sections must be read from the
   442   /// file. In this case the first phase would read the node set and one
   443   /// of the arc sets, while the second phase would read the second arc
   444   /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
   445   /// The previously read label node map should be passed to the \c
   446   /// useNodes() functions. Another application of multipass reading when
   447   /// paths are given as a node map or an arc map.
   448   /// It is impossible to read this in
   449   /// a single pass, because the arcs are not constructed when the node
   450   /// maps are read.
   451   template <typename _Digraph>
   452   class DigraphReader {
   453   public:
   454 
   455     typedef _Digraph Digraph;
   456     TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
   457 
   458   private:
   459 
   460 
   461     std::istream* _is;
   462     bool local_is;
   463     std::string _filename;
   464 
   465     Digraph& _digraph;
   466 
   467     std::string _nodes_caption;
   468     std::string _arcs_caption;
   469     std::string _attributes_caption;
   470 
   471     typedef std::map<std::string, Node> NodeIndex;
   472     NodeIndex _node_index;
   473     typedef std::map<std::string, Arc> ArcIndex;
   474     ArcIndex _arc_index;
   475 
   476     typedef std::vector<std::pair<std::string,
   477       _reader_bits::MapStorageBase<Node>*> > NodeMaps;
   478     NodeMaps _node_maps;
   479 
   480     typedef std::vector<std::pair<std::string,
   481       _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
   482     ArcMaps _arc_maps;
   483 
   484     typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
   485       Attributes;
   486     Attributes _attributes;
   487 
   488     bool _use_nodes;
   489     bool _use_arcs;
   490 
   491     bool _skip_nodes;
   492     bool _skip_arcs;
   493 
   494     int line_num;
   495     std::istringstream line;
   496 
   497   public:
   498 
   499     /// \brief Constructor
   500     ///
   501     /// Construct a directed graph reader, which reads from the given
   502     /// input stream.
   503     DigraphReader(Digraph& digraph, std::istream& is = std::cin)
   504       : _is(&is), local_is(false), _digraph(digraph),
   505         _use_nodes(false), _use_arcs(false),
   506         _skip_nodes(false), _skip_arcs(false) {}
   507 
   508     /// \brief Constructor
   509     ///
   510     /// Construct a directed graph reader, which reads from the given
   511     /// file.
   512     DigraphReader(Digraph& digraph, const std::string& fn)
   513       : _is(new std::ifstream(fn.c_str())), local_is(true),
   514         _filename(fn), _digraph(digraph),
   515         _use_nodes(false), _use_arcs(false),
   516         _skip_nodes(false), _skip_arcs(false) {
   517       if (!(*_is)) {
   518         delete _is;
   519         throw IoError("Cannot open file", fn);
   520       }
   521     }
   522 
   523     /// \brief Constructor
   524     ///
   525     /// Construct a directed graph reader, which reads from the given
   526     /// file.
   527     DigraphReader(Digraph& digraph, const char* fn)
   528       : _is(new std::ifstream(fn)), local_is(true),
   529         _filename(fn), _digraph(digraph),
   530         _use_nodes(false), _use_arcs(false),
   531         _skip_nodes(false), _skip_arcs(false) {
   532       if (!(*_is)) {
   533         delete _is;
   534         throw IoError("Cannot open file", fn);
   535       }
   536     }
   537 
   538     /// \brief Destructor
   539     ~DigraphReader() {
   540       for (typename NodeMaps::iterator it = _node_maps.begin();
   541            it != _node_maps.end(); ++it) {
   542         delete it->second;
   543       }
   544 
   545       for (typename ArcMaps::iterator it = _arc_maps.begin();
   546            it != _arc_maps.end(); ++it) {
   547         delete it->second;
   548       }
   549 
   550       for (typename Attributes::iterator it = _attributes.begin();
   551            it != _attributes.end(); ++it) {
   552         delete it->second;
   553       }
   554 
   555       if (local_is) {
   556         delete _is;
   557       }
   558 
   559     }
   560 
   561   private:
   562 
   563     template <typename DGR>
   564     friend DigraphReader<DGR> digraphReader(DGR& digraph, std::istream& is);
   565     template <typename DGR>
   566     friend DigraphReader<DGR> digraphReader(DGR& digraph, 
   567                                             const std::string& fn);
   568     template <typename DGR>
   569     friend DigraphReader<DGR> digraphReader(DGR& digraph, const char *fn);
   570 
   571     DigraphReader(DigraphReader& other)
   572       : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
   573         _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
   574         _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
   575 
   576       other._is = 0;
   577       other.local_is = false;
   578 
   579       _node_index.swap(other._node_index);
   580       _arc_index.swap(other._arc_index);
   581 
   582       _node_maps.swap(other._node_maps);
   583       _arc_maps.swap(other._arc_maps);
   584       _attributes.swap(other._attributes);
   585 
   586       _nodes_caption = other._nodes_caption;
   587       _arcs_caption = other._arcs_caption;
   588       _attributes_caption = other._attributes_caption;
   589 
   590     }
   591 
   592     DigraphReader& operator=(const DigraphReader&);
   593 
   594   public:
   595 
   596     /// \name Reading rules
   597     /// @{
   598 
   599     /// \brief Node map reading rule
   600     ///
   601     /// Add a node map reading rule to the reader.
   602     template <typename Map>
   603     DigraphReader& nodeMap(const std::string& caption, Map& map) {
   604       checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
   605       _reader_bits::MapStorageBase<Node>* storage =
   606         new _reader_bits::MapStorage<Node, Map>(map);
   607       _node_maps.push_back(std::make_pair(caption, storage));
   608       return *this;
   609     }
   610 
   611     /// \brief Node map reading rule
   612     ///
   613     /// Add a node map reading rule with specialized converter to the
   614     /// reader.
   615     template <typename Map, typename Converter>
   616     DigraphReader& nodeMap(const std::string& caption, Map& map,
   617                            const Converter& converter = Converter()) {
   618       checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
   619       _reader_bits::MapStorageBase<Node>* storage =
   620         new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
   621       _node_maps.push_back(std::make_pair(caption, storage));
   622       return *this;
   623     }
   624 
   625     /// \brief Arc map reading rule
   626     ///
   627     /// Add an arc map reading rule to the reader.
   628     template <typename Map>
   629     DigraphReader& arcMap(const std::string& caption, Map& map) {
   630       checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
   631       _reader_bits::MapStorageBase<Arc>* storage =
   632         new _reader_bits::MapStorage<Arc, Map>(map);
   633       _arc_maps.push_back(std::make_pair(caption, storage));
   634       return *this;
   635     }
   636 
   637     /// \brief Arc map reading rule
   638     ///
   639     /// Add an arc map reading rule with specialized converter to the
   640     /// reader.
   641     template <typename Map, typename Converter>
   642     DigraphReader& arcMap(const std::string& caption, Map& map,
   643                           const Converter& converter = Converter()) {
   644       checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
   645       _reader_bits::MapStorageBase<Arc>* storage =
   646         new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
   647       _arc_maps.push_back(std::make_pair(caption, storage));
   648       return *this;
   649     }
   650 
   651     /// \brief Attribute reading rule
   652     ///
   653     /// Add an attribute reading rule to the reader.
   654     template <typename Value>
   655     DigraphReader& attribute(const std::string& caption, Value& value) {
   656       _reader_bits::ValueStorageBase* storage =
   657         new _reader_bits::ValueStorage<Value>(value);
   658       _attributes.insert(std::make_pair(caption, storage));
   659       return *this;
   660     }
   661 
   662     /// \brief Attribute reading rule
   663     ///
   664     /// Add an attribute reading rule with specialized converter to the
   665     /// reader.
   666     template <typename Value, typename Converter>
   667     DigraphReader& attribute(const std::string& caption, Value& value,
   668                              const Converter& converter = Converter()) {
   669       _reader_bits::ValueStorageBase* storage =
   670         new _reader_bits::ValueStorage<Value, Converter>(value, converter);
   671       _attributes.insert(std::make_pair(caption, storage));
   672       return *this;
   673     }
   674 
   675     /// \brief Node reading rule
   676     ///
   677     /// Add a node reading rule to reader.
   678     DigraphReader& node(const std::string& caption, Node& node) {
   679       typedef _reader_bits::MapLookUpConverter<Node> Converter;
   680       Converter converter(_node_index);
   681       _reader_bits::ValueStorageBase* storage =
   682         new _reader_bits::ValueStorage<Node, Converter>(node, converter);
   683       _attributes.insert(std::make_pair(caption, storage));
   684       return *this;
   685     }
   686 
   687     /// \brief Arc reading rule
   688     ///
   689     /// Add an arc reading rule to reader.
   690     DigraphReader& arc(const std::string& caption, Arc& arc) {
   691       typedef _reader_bits::MapLookUpConverter<Arc> Converter;
   692       Converter converter(_arc_index);
   693       _reader_bits::ValueStorageBase* storage =
   694         new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
   695       _attributes.insert(std::make_pair(caption, storage));
   696       return *this;
   697     }
   698 
   699     /// @}
   700 
   701     /// \name Select section by name
   702     /// @{
   703 
   704     /// \brief Set \c \@nodes section to be read
   705     ///
   706     /// Set \c \@nodes section to be read
   707     DigraphReader& nodes(const std::string& caption) {
   708       _nodes_caption = caption;
   709       return *this;
   710     }
   711 
   712     /// \brief Set \c \@arcs section to be read
   713     ///
   714     /// Set \c \@arcs section to be read
   715     DigraphReader& arcs(const std::string& caption) {
   716       _arcs_caption = caption;
   717       return *this;
   718     }
   719 
   720     /// \brief Set \c \@attributes section to be read
   721     ///
   722     /// Set \c \@attributes section to be read
   723     DigraphReader& attributes(const std::string& caption) {
   724       _attributes_caption = caption;
   725       return *this;
   726     }
   727 
   728     /// @}
   729 
   730     /// \name Using previously constructed node or arc set
   731     /// @{
   732 
   733     /// \brief Use previously constructed node set
   734     ///
   735     /// Use previously constructed node set, and specify the node
   736     /// label map.
   737     template <typename Map>
   738     DigraphReader& useNodes(const Map& map) {
   739       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
   740       LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
   741       _use_nodes = true;
   742       _writer_bits::DefaultConverter<typename Map::Value> converter;
   743       for (NodeIt n(_digraph); n != INVALID; ++n) {
   744         _node_index.insert(std::make_pair(converter(map[n]), n));
   745       }
   746       return *this;
   747     }
   748 
   749     /// \brief Use previously constructed node set
   750     ///
   751     /// Use previously constructed node set, and specify the node
   752     /// label map and a functor which converts the label map values to
   753     /// \c std::string.
   754     template <typename Map, typename Converter>
   755     DigraphReader& useNodes(const Map& map,
   756                             const Converter& converter = Converter()) {
   757       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
   758       LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
   759       _use_nodes = true;
   760       for (NodeIt n(_digraph); n != INVALID; ++n) {
   761         _node_index.insert(std::make_pair(converter(map[n]), n));
   762       }
   763       return *this;
   764     }
   765 
   766     /// \brief Use previously constructed arc set
   767     ///
   768     /// Use previously constructed arc set, and specify the arc
   769     /// label map.
   770     template <typename Map>
   771     DigraphReader& useArcs(const Map& map) {
   772       checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
   773       LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
   774       _use_arcs = true;
   775       _writer_bits::DefaultConverter<typename Map::Value> converter;
   776       for (ArcIt a(_digraph); a != INVALID; ++a) {
   777         _arc_index.insert(std::make_pair(converter(map[a]), a));
   778       }
   779       return *this;
   780     }
   781 
   782     /// \brief Use previously constructed arc set
   783     ///
   784     /// Use previously constructed arc set, and specify the arc
   785     /// label map and a functor which converts the label map values to
   786     /// \c std::string.
   787     template <typename Map, typename Converter>
   788     DigraphReader& useArcs(const Map& map,
   789                            const Converter& converter = Converter()) {
   790       checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
   791       LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
   792       _use_arcs = true;
   793       for (ArcIt a(_digraph); a != INVALID; ++a) {
   794         _arc_index.insert(std::make_pair(converter(map[a]), a));
   795       }
   796       return *this;
   797     }
   798 
   799     /// \brief Skips the reading of node section
   800     ///
   801     /// Omit the reading of the node section. This implies that each node
   802     /// map reading rule will be abandoned, and the nodes of the graph
   803     /// will not be constructed, which usually cause that the arc set
   804     /// could not be read due to lack of node name resolving.
   805     /// Therefore \c skipArcs() function should also be used, or
   806     /// \c useNodes() should be used to specify the label of the nodes.
   807     DigraphReader& skipNodes() {
   808       LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
   809       _skip_nodes = true;
   810       return *this;
   811     }
   812 
   813     /// \brief Skips the reading of arc section
   814     ///
   815     /// Omit the reading of the arc section. This implies that each arc
   816     /// map reading rule will be abandoned, and the arcs of the graph
   817     /// will not be constructed.
   818     DigraphReader& skipArcs() {
   819       LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
   820       _skip_arcs = true;
   821       return *this;
   822     }
   823 
   824     /// @}
   825 
   826   private:
   827 
   828     bool readLine() {
   829       std::string str;
   830       while(++line_num, std::getline(*_is, str)) {
   831         line.clear(); line.str(str);
   832         char c;
   833         if (line >> std::ws >> c && c != '#') {
   834           line.putback(c);
   835           return true;
   836         }
   837       }
   838       return false;
   839     }
   840 
   841     bool readSuccess() {
   842       return static_cast<bool>(*_is);
   843     }
   844 
   845     void skipSection() {
   846       char c;
   847       while (readSuccess() && line >> c && c != '@') {
   848         readLine();
   849       }
   850       line.putback(c);
   851     }
   852 
   853     void readNodes() {
   854 
   855       std::vector<int> map_index(_node_maps.size());
   856       int map_num, label_index;
   857 
   858       char c;
   859       if (!readLine() || !(line >> c) || c == '@') {
   860         if (readSuccess() && line) line.putback(c);
   861         if (!_node_maps.empty())
   862           throw FormatError("Cannot find map names");
   863         return;
   864       }
   865       line.putback(c);
   866 
   867       {
   868         std::map<std::string, int> maps;
   869 
   870         std::string map;
   871         int index = 0;
   872         while (_reader_bits::readToken(line, map)) {
   873           if (maps.find(map) != maps.end()) {
   874             std::ostringstream msg;
   875             msg << "Multiple occurence of node map: " << map;
   876             throw FormatError(msg.str());
   877           }
   878           maps.insert(std::make_pair(map, index));
   879           ++index;
   880         }
   881 
   882         for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
   883           std::map<std::string, int>::iterator jt =
   884             maps.find(_node_maps[i].first);
   885           if (jt == maps.end()) {
   886             std::ostringstream msg;
   887             msg << "Map not found: " << _node_maps[i].first;
   888             throw FormatError(msg.str());
   889           }
   890           map_index[i] = jt->second;
   891         }
   892 
   893         {
   894           std::map<std::string, int>::iterator jt = maps.find("label");
   895           if (jt != maps.end()) {
   896             label_index = jt->second;
   897           } else {
   898             label_index = -1;
   899           }
   900         }
   901         map_num = maps.size();
   902       }
   903 
   904       while (readLine() && line >> c && c != '@') {
   905         line.putback(c);
   906 
   907         std::vector<std::string> tokens(map_num);
   908         for (int i = 0; i < map_num; ++i) {
   909           if (!_reader_bits::readToken(line, tokens[i])) {
   910             std::ostringstream msg;
   911             msg << "Column not found (" << i + 1 << ")";
   912             throw FormatError(msg.str());
   913           }
   914         }
   915         if (line >> std::ws >> c)
   916           throw FormatError("Extra character at the end of line");
   917 
   918         Node n;
   919         if (!_use_nodes) {
   920           n = _digraph.addNode();
   921           if (label_index != -1)
   922             _node_index.insert(std::make_pair(tokens[label_index], n));
   923         } else {
   924           if (label_index == -1)
   925             throw FormatError("Label map not found");
   926           typename std::map<std::string, Node>::iterator it =
   927             _node_index.find(tokens[label_index]);
   928           if (it == _node_index.end()) {
   929             std::ostringstream msg;
   930             msg << "Node with label not found: " << tokens[label_index];
   931             throw FormatError(msg.str());
   932           }
   933           n = it->second;
   934         }
   935 
   936         for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
   937           _node_maps[i].second->set(n, tokens[map_index[i]]);
   938         }
   939 
   940       }
   941       if (readSuccess()) {
   942         line.putback(c);
   943       }
   944     }
   945 
   946     void readArcs() {
   947 
   948       std::vector<int> map_index(_arc_maps.size());
   949       int map_num, label_index;
   950 
   951       char c;
   952       if (!readLine() || !(line >> c) || c == '@') {
   953         if (readSuccess() && line) line.putback(c);
   954         if (!_arc_maps.empty())
   955           throw FormatError("Cannot find map names");
   956         return;
   957       }
   958       line.putback(c);
   959 
   960       {
   961         std::map<std::string, int> maps;
   962 
   963         std::string map;
   964         int index = 0;
   965         while (_reader_bits::readToken(line, map)) {
   966           if (maps.find(map) != maps.end()) {
   967             std::ostringstream msg;
   968             msg << "Multiple occurence of arc map: " << map;
   969             throw FormatError(msg.str());
   970           }
   971           maps.insert(std::make_pair(map, index));
   972           ++index;
   973         }
   974 
   975         for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
   976           std::map<std::string, int>::iterator jt =
   977             maps.find(_arc_maps[i].first);
   978           if (jt == maps.end()) {
   979             std::ostringstream msg;
   980             msg << "Map not found: " << _arc_maps[i].first;
   981             throw FormatError(msg.str());
   982           }
   983           map_index[i] = jt->second;
   984         }
   985 
   986         {
   987           std::map<std::string, int>::iterator jt = maps.find("label");
   988           if (jt != maps.end()) {
   989             label_index = jt->second;
   990           } else {
   991             label_index = -1;
   992           }
   993         }
   994         map_num = maps.size();
   995       }
   996 
   997       while (readLine() && line >> c && c != '@') {
   998         line.putback(c);
   999 
  1000         std::string source_token;
  1001         std::string target_token;
  1002 
  1003         if (!_reader_bits::readToken(line, source_token))
  1004           throw FormatError("Source not found");
  1005 
  1006         if (!_reader_bits::readToken(line, target_token))
  1007           throw FormatError("Target not found");
  1008 
  1009         std::vector<std::string> tokens(map_num);
  1010         for (int i = 0; i < map_num; ++i) {
  1011           if (!_reader_bits::readToken(line, tokens[i])) {
  1012             std::ostringstream msg;
  1013             msg << "Column not found (" << i + 1 << ")";
  1014             throw FormatError(msg.str());
  1015           }
  1016         }
  1017         if (line >> std::ws >> c)
  1018           throw FormatError("Extra character at the end of line");
  1019 
  1020         Arc a;
  1021         if (!_use_arcs) {
  1022 
  1023           typename NodeIndex::iterator it;
  1024 
  1025           it = _node_index.find(source_token);
  1026           if (it == _node_index.end()) {
  1027             std::ostringstream msg;
  1028             msg << "Item not found: " << source_token;
  1029             throw FormatError(msg.str());
  1030           }
  1031           Node source = it->second;
  1032 
  1033           it = _node_index.find(target_token);
  1034           if (it == _node_index.end()) {
  1035             std::ostringstream msg;
  1036             msg << "Item not found: " << target_token;
  1037             throw FormatError(msg.str());
  1038           }
  1039           Node target = it->second;
  1040 
  1041           a = _digraph.addArc(source, target);
  1042           if (label_index != -1)
  1043             _arc_index.insert(std::make_pair(tokens[label_index], a));
  1044         } else {
  1045           if (label_index == -1)
  1046             throw FormatError("Label map not found");
  1047           typename std::map<std::string, Arc>::iterator it =
  1048             _arc_index.find(tokens[label_index]);
  1049           if (it == _arc_index.end()) {
  1050             std::ostringstream msg;
  1051             msg << "Arc with label not found: " << tokens[label_index];
  1052             throw FormatError(msg.str());
  1053           }
  1054           a = it->second;
  1055         }
  1056 
  1057         for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
  1058           _arc_maps[i].second->set(a, tokens[map_index[i]]);
  1059         }
  1060 
  1061       }
  1062       if (readSuccess()) {
  1063         line.putback(c);
  1064       }
  1065     }
  1066 
  1067     void readAttributes() {
  1068 
  1069       std::set<std::string> read_attr;
  1070 
  1071       char c;
  1072       while (readLine() && line >> c && c != '@') {
  1073         line.putback(c);
  1074 
  1075         std::string attr, token;
  1076         if (!_reader_bits::readToken(line, attr))
  1077           throw FormatError("Attribute name not found");
  1078         if (!_reader_bits::readToken(line, token))
  1079           throw FormatError("Attribute value not found");
  1080         if (line >> c)
  1081           throw FormatError("Extra character at the end of line");
  1082 
  1083         {
  1084           std::set<std::string>::iterator it = read_attr.find(attr);
  1085           if (it != read_attr.end()) {
  1086             std::ostringstream msg;
  1087             msg << "Multiple occurence of attribute: " << attr;
  1088             throw FormatError(msg.str());
  1089           }
  1090           read_attr.insert(attr);
  1091         }
  1092 
  1093         {
  1094           typename Attributes::iterator it = _attributes.lower_bound(attr);
  1095           while (it != _attributes.end() && it->first == attr) {
  1096             it->second->set(token);
  1097             ++it;
  1098           }
  1099         }
  1100 
  1101       }
  1102       if (readSuccess()) {
  1103         line.putback(c);
  1104       }
  1105       for (typename Attributes::iterator it = _attributes.begin();
  1106            it != _attributes.end(); ++it) {
  1107         if (read_attr.find(it->first) == read_attr.end()) {
  1108           std::ostringstream msg;
  1109           msg << "Attribute not found: " << it->first;
  1110           throw FormatError(msg.str());
  1111         }
  1112       }
  1113     }
  1114 
  1115   public:
  1116 
  1117     /// \name Execution of the reader
  1118     /// @{
  1119 
  1120     /// \brief Start the batch processing
  1121     ///
  1122     /// This function starts the batch processing
  1123     void run() {
  1124       LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
  1125 
  1126       bool nodes_done = _skip_nodes;
  1127       bool arcs_done = _skip_arcs;
  1128       bool attributes_done = false;
  1129 
  1130       line_num = 0;
  1131       readLine();
  1132       skipSection();
  1133 
  1134       while (readSuccess()) {
  1135         try {
  1136           char c;
  1137           std::string section, caption;
  1138           line >> c;
  1139           _reader_bits::readToken(line, section);
  1140           _reader_bits::readToken(line, caption);
  1141 
  1142           if (line >> c)
  1143             throw FormatError("Extra character at the end of line");
  1144 
  1145           if (section == "nodes" && !nodes_done) {
  1146             if (_nodes_caption.empty() || _nodes_caption == caption) {
  1147               readNodes();
  1148               nodes_done = true;
  1149             }
  1150           } else if ((section == "arcs" || section == "edges") &&
  1151                      !arcs_done) {
  1152             if (_arcs_caption.empty() || _arcs_caption == caption) {
  1153               readArcs();
  1154               arcs_done = true;
  1155             }
  1156           } else if (section == "attributes" && !attributes_done) {
  1157             if (_attributes_caption.empty() || _attributes_caption == caption) {
  1158               readAttributes();
  1159               attributes_done = true;
  1160             }
  1161           } else {
  1162             readLine();
  1163             skipSection();
  1164           }
  1165         } catch (FormatError& error) {
  1166           error.line(line_num);
  1167           error.file(_filename);
  1168           throw;
  1169         }
  1170       }
  1171 
  1172       if (!nodes_done) {
  1173         throw FormatError("Section @nodes not found");
  1174       }
  1175 
  1176       if (!arcs_done) {
  1177         throw FormatError("Section @arcs not found");
  1178       }
  1179 
  1180       if (!attributes_done && !_attributes.empty()) {
  1181         throw FormatError("Section @attributes not found");
  1182       }
  1183 
  1184     }
  1185 
  1186     /// @}
  1187 
  1188   };
  1189 
  1190   /// \brief Return a \ref DigraphReader class
  1191   ///
  1192   /// This function just returns a \ref DigraphReader class.
  1193   /// \relates DigraphReader
  1194   template <typename Digraph>
  1195   DigraphReader<Digraph> digraphReader(Digraph& digraph, std::istream& is) {
  1196     DigraphReader<Digraph> tmp(digraph, is);
  1197     return tmp;
  1198   }
  1199 
  1200   /// \brief Return a \ref DigraphReader class
  1201   ///
  1202   /// This function just returns a \ref DigraphReader class.
  1203   /// \relates DigraphReader
  1204   template <typename Digraph>
  1205   DigraphReader<Digraph> digraphReader(Digraph& digraph,
  1206                                        const std::string& fn) {
  1207     DigraphReader<Digraph> tmp(digraph, fn);
  1208     return tmp;
  1209   }
  1210 
  1211   /// \brief Return a \ref DigraphReader class
  1212   ///
  1213   /// This function just returns a \ref DigraphReader class.
  1214   /// \relates DigraphReader
  1215   template <typename Digraph>
  1216   DigraphReader<Digraph> digraphReader(Digraph& digraph, const char* fn) {
  1217     DigraphReader<Digraph> tmp(digraph, fn);
  1218     return tmp;
  1219   }
  1220 
  1221   template <typename Graph>
  1222   class GraphReader;
  1223  
  1224   template <typename Graph>
  1225   GraphReader<Graph> graphReader(Graph& graph, 
  1226                                  std::istream& is = std::cin);
  1227   template <typename Graph>
  1228   GraphReader<Graph> graphReader(Graph& graph, const std::string& fn);
  1229   template <typename Graph>
  1230   GraphReader<Graph> graphReader(Graph& graph, const char *fn);
  1231 
  1232   /// \ingroup lemon_io
  1233   ///
  1234   /// \brief \ref lgf-format "LGF" reader for undirected graphs
  1235   ///
  1236   /// This utility reads an \ref lgf-format "LGF" file.
  1237   ///
  1238   /// It can be used almost the same way as \c DigraphReader.
  1239   /// The only difference is that this class can handle edges and
  1240   /// edge maps as well as arcs and arc maps.
  1241   ///
  1242   /// The columns in the \c \@edges (or \c \@arcs) section are the
  1243   /// edge maps. However, if there are two maps with the same name
  1244   /// prefixed with \c '+' and \c '-', then these can be read into an
  1245   /// arc map.  Similarly, an attribute can be read into an arc, if
  1246   /// it's value is an edge label prefixed with \c '+' or \c '-'.
  1247   template <typename _Graph>
  1248   class GraphReader {
  1249   public:
  1250 
  1251     typedef _Graph Graph;
  1252     TEMPLATE_GRAPH_TYPEDEFS(Graph);
  1253 
  1254   private:
  1255 
  1256     std::istream* _is;
  1257     bool local_is;
  1258     std::string _filename;
  1259 
  1260     Graph& _graph;
  1261 
  1262     std::string _nodes_caption;
  1263     std::string _edges_caption;
  1264     std::string _attributes_caption;
  1265 
  1266     typedef std::map<std::string, Node> NodeIndex;
  1267     NodeIndex _node_index;
  1268     typedef std::map<std::string, Edge> EdgeIndex;
  1269     EdgeIndex _edge_index;
  1270 
  1271     typedef std::vector<std::pair<std::string,
  1272       _reader_bits::MapStorageBase<Node>*> > NodeMaps;
  1273     NodeMaps _node_maps;
  1274 
  1275     typedef std::vector<std::pair<std::string,
  1276       _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
  1277     EdgeMaps _edge_maps;
  1278 
  1279     typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
  1280       Attributes;
  1281     Attributes _attributes;
  1282 
  1283     bool _use_nodes;
  1284     bool _use_edges;
  1285 
  1286     bool _skip_nodes;
  1287     bool _skip_edges;
  1288 
  1289     int line_num;
  1290     std::istringstream line;
  1291 
  1292   public:
  1293 
  1294     /// \brief Constructor
  1295     ///
  1296     /// Construct an undirected graph reader, which reads from the given
  1297     /// input stream.
  1298     GraphReader(Graph& graph, std::istream& is = std::cin)
  1299       : _is(&is), local_is(false), _graph(graph),
  1300         _use_nodes(false), _use_edges(false),
  1301         _skip_nodes(false), _skip_edges(false) {}
  1302 
  1303     /// \brief Constructor
  1304     ///
  1305     /// Construct an undirected graph reader, which reads from the given
  1306     /// file.
  1307     GraphReader(Graph& graph, const std::string& fn)
  1308       : _is(new std::ifstream(fn.c_str())), local_is(true),
  1309         _filename(fn), _graph(graph),
  1310         _use_nodes(false), _use_edges(false),
  1311         _skip_nodes(false), _skip_edges(false) {
  1312       if (!(*_is)) {
  1313         delete _is;
  1314         throw IoError("Cannot open file", fn);
  1315       }
  1316     }
  1317 
  1318     /// \brief Constructor
  1319     ///
  1320     /// Construct an undirected graph reader, which reads from the given
  1321     /// file.
  1322     GraphReader(Graph& graph, const char* fn)
  1323       : _is(new std::ifstream(fn)), local_is(true),
  1324         _filename(fn), _graph(graph),
  1325         _use_nodes(false), _use_edges(false),
  1326         _skip_nodes(false), _skip_edges(false) {
  1327       if (!(*_is)) {
  1328         delete _is;
  1329         throw IoError("Cannot open file", fn);
  1330       }
  1331     }
  1332 
  1333     /// \brief Destructor
  1334     ~GraphReader() {
  1335       for (typename NodeMaps::iterator it = _node_maps.begin();
  1336            it != _node_maps.end(); ++it) {
  1337         delete it->second;
  1338       }
  1339 
  1340       for (typename EdgeMaps::iterator it = _edge_maps.begin();
  1341            it != _edge_maps.end(); ++it) {
  1342         delete it->second;
  1343       }
  1344 
  1345       for (typename Attributes::iterator it = _attributes.begin();
  1346            it != _attributes.end(); ++it) {
  1347         delete it->second;
  1348       }
  1349 
  1350       if (local_is) {
  1351         delete _is;
  1352       }
  1353 
  1354     }
  1355 
  1356   private:
  1357     template <typename GR>
  1358     friend GraphReader<GR> graphReader(GR& graph, std::istream& is);
  1359     template <typename GR>
  1360     friend GraphReader<GR> graphReader(GR& graph, const std::string& fn); 
  1361     template <typename GR>
  1362     friend GraphReader<GR> graphReader(GR& graph, const char *fn);
  1363 
  1364     GraphReader(GraphReader& other)
  1365       : _is(other._is), local_is(other.local_is), _graph(other._graph),
  1366         _use_nodes(other._use_nodes), _use_edges(other._use_edges),
  1367         _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
  1368 
  1369       other._is = 0;
  1370       other.local_is = false;
  1371 
  1372       _node_index.swap(other._node_index);
  1373       _edge_index.swap(other._edge_index);
  1374 
  1375       _node_maps.swap(other._node_maps);
  1376       _edge_maps.swap(other._edge_maps);
  1377       _attributes.swap(other._attributes);
  1378 
  1379       _nodes_caption = other._nodes_caption;
  1380       _edges_caption = other._edges_caption;
  1381       _attributes_caption = other._attributes_caption;
  1382 
  1383     }
  1384 
  1385     GraphReader& operator=(const GraphReader&);
  1386 
  1387   public:
  1388 
  1389     /// \name Reading rules
  1390     /// @{
  1391 
  1392     /// \brief Node map reading rule
  1393     ///
  1394     /// Add a node map reading rule to the reader.
  1395     template <typename Map>
  1396     GraphReader& nodeMap(const std::string& caption, Map& map) {
  1397       checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
  1398       _reader_bits::MapStorageBase<Node>* storage =
  1399         new _reader_bits::MapStorage<Node, Map>(map);
  1400       _node_maps.push_back(std::make_pair(caption, storage));
  1401       return *this;
  1402     }
  1403 
  1404     /// \brief Node map reading rule
  1405     ///
  1406     /// Add a node map reading rule with specialized converter to the
  1407     /// reader.
  1408     template <typename Map, typename Converter>
  1409     GraphReader& nodeMap(const std::string& caption, Map& map,
  1410                            const Converter& converter = Converter()) {
  1411       checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
  1412       _reader_bits::MapStorageBase<Node>* storage =
  1413         new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
  1414       _node_maps.push_back(std::make_pair(caption, storage));
  1415       return *this;
  1416     }
  1417 
  1418     /// \brief Edge map reading rule
  1419     ///
  1420     /// Add an edge map reading rule to the reader.
  1421     template <typename Map>
  1422     GraphReader& edgeMap(const std::string& caption, Map& map) {
  1423       checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
  1424       _reader_bits::MapStorageBase<Edge>* storage =
  1425         new _reader_bits::MapStorage<Edge, Map>(map);
  1426       _edge_maps.push_back(std::make_pair(caption, storage));
  1427       return *this;
  1428     }
  1429 
  1430     /// \brief Edge map reading rule
  1431     ///
  1432     /// Add an edge map reading rule with specialized converter to the
  1433     /// reader.
  1434     template <typename Map, typename Converter>
  1435     GraphReader& edgeMap(const std::string& caption, Map& map,
  1436                           const Converter& converter = Converter()) {
  1437       checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
  1438       _reader_bits::MapStorageBase<Edge>* storage =
  1439         new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
  1440       _edge_maps.push_back(std::make_pair(caption, storage));
  1441       return *this;
  1442     }
  1443 
  1444     /// \brief Arc map reading rule
  1445     ///
  1446     /// Add an arc map reading rule to the reader.
  1447     template <typename Map>
  1448     GraphReader& arcMap(const std::string& caption, Map& map) {
  1449       checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
  1450       _reader_bits::MapStorageBase<Edge>* forward_storage =
  1451         new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
  1452       _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
  1453       _reader_bits::MapStorageBase<Edge>* backward_storage =
  1454         new _reader_bits::GraphArcMapStorage<Graph, false, Map>(_graph, map);
  1455       _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
  1456       return *this;
  1457     }
  1458 
  1459     /// \brief Arc map reading rule
  1460     ///
  1461     /// Add an arc map reading rule with specialized converter to the
  1462     /// reader.
  1463     template <typename Map, typename Converter>
  1464     GraphReader& arcMap(const std::string& caption, Map& map,
  1465                           const Converter& converter = Converter()) {
  1466       checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
  1467       _reader_bits::MapStorageBase<Edge>* forward_storage =
  1468         new _reader_bits::GraphArcMapStorage<Graph, true, Map, Converter>
  1469         (_graph, map, converter);
  1470       _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
  1471       _reader_bits::MapStorageBase<Edge>* backward_storage =
  1472         new _reader_bits::GraphArcMapStorage<Graph, false, Map, Converter>
  1473         (_graph, map, converter);
  1474       _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
  1475       return *this;
  1476     }
  1477 
  1478     /// \brief Attribute reading rule
  1479     ///
  1480     /// Add an attribute reading rule to the reader.
  1481     template <typename Value>
  1482     GraphReader& attribute(const std::string& caption, Value& value) {
  1483       _reader_bits::ValueStorageBase* storage =
  1484         new _reader_bits::ValueStorage<Value>(value);
  1485       _attributes.insert(std::make_pair(caption, storage));
  1486       return *this;
  1487     }
  1488 
  1489     /// \brief Attribute reading rule
  1490     ///
  1491     /// Add an attribute reading rule with specialized converter to the
  1492     /// reader.
  1493     template <typename Value, typename Converter>
  1494     GraphReader& attribute(const std::string& caption, Value& value,
  1495                              const Converter& converter = Converter()) {
  1496       _reader_bits::ValueStorageBase* storage =
  1497         new _reader_bits::ValueStorage<Value, Converter>(value, converter);
  1498       _attributes.insert(std::make_pair(caption, storage));
  1499       return *this;
  1500     }
  1501 
  1502     /// \brief Node reading rule
  1503     ///
  1504     /// Add a node reading rule to reader.
  1505     GraphReader& node(const std::string& caption, Node& node) {
  1506       typedef _reader_bits::MapLookUpConverter<Node> Converter;
  1507       Converter converter(_node_index);
  1508       _reader_bits::ValueStorageBase* storage =
  1509         new _reader_bits::ValueStorage<Node, Converter>(node, converter);
  1510       _attributes.insert(std::make_pair(caption, storage));
  1511       return *this;
  1512     }
  1513 
  1514     /// \brief Edge reading rule
  1515     ///
  1516     /// Add an edge reading rule to reader.
  1517     GraphReader& edge(const std::string& caption, Edge& edge) {
  1518       typedef _reader_bits::MapLookUpConverter<Edge> Converter;
  1519       Converter converter(_edge_index);
  1520       _reader_bits::ValueStorageBase* storage =
  1521         new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
  1522       _attributes.insert(std::make_pair(caption, storage));
  1523       return *this;
  1524     }
  1525 
  1526     /// \brief Arc reading rule
  1527     ///
  1528     /// Add an arc reading rule to reader.
  1529     GraphReader& arc(const std::string& caption, Arc& arc) {
  1530       typedef _reader_bits::GraphArcLookUpConverter<Graph> Converter;
  1531       Converter converter(_graph, _edge_index);
  1532       _reader_bits::ValueStorageBase* storage =
  1533         new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
  1534       _attributes.insert(std::make_pair(caption, storage));
  1535       return *this;
  1536     }
  1537 
  1538     /// @}
  1539 
  1540     /// \name Select section by name
  1541     /// @{
  1542 
  1543     /// \brief Set \c \@nodes section to be read
  1544     ///
  1545     /// Set \c \@nodes section to be read.
  1546     GraphReader& nodes(const std::string& caption) {
  1547       _nodes_caption = caption;
  1548       return *this;
  1549     }
  1550 
  1551     /// \brief Set \c \@edges section to be read
  1552     ///
  1553     /// Set \c \@edges section to be read.
  1554     GraphReader& edges(const std::string& caption) {
  1555       _edges_caption = caption;
  1556       return *this;
  1557     }
  1558 
  1559     /// \brief Set \c \@attributes section to be read
  1560     ///
  1561     /// Set \c \@attributes section to be read.
  1562     GraphReader& attributes(const std::string& caption) {
  1563       _attributes_caption = caption;
  1564       return *this;
  1565     }
  1566 
  1567     /// @}
  1568 
  1569     /// \name Using previously constructed node or edge set
  1570     /// @{
  1571 
  1572     /// \brief Use previously constructed node set
  1573     ///
  1574     /// Use previously constructed node set, and specify the node
  1575     /// label map.
  1576     template <typename Map>
  1577     GraphReader& useNodes(const Map& map) {
  1578       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
  1579       LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
  1580       _use_nodes = true;
  1581       _writer_bits::DefaultConverter<typename Map::Value> converter;
  1582       for (NodeIt n(_graph); n != INVALID; ++n) {
  1583         _node_index.insert(std::make_pair(converter(map[n]), n));
  1584       }
  1585       return *this;
  1586     }
  1587 
  1588     /// \brief Use previously constructed node set
  1589     ///
  1590     /// Use previously constructed node set, and specify the node
  1591     /// label map and a functor which converts the label map values to
  1592     /// \c std::string.
  1593     template <typename Map, typename Converter>
  1594     GraphReader& useNodes(const Map& map,
  1595                             const Converter& converter = Converter()) {
  1596       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
  1597       LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
  1598       _use_nodes = true;
  1599       for (NodeIt n(_graph); n != INVALID; ++n) {
  1600         _node_index.insert(std::make_pair(converter(map[n]), n));
  1601       }
  1602       return *this;
  1603     }
  1604 
  1605     /// \brief Use previously constructed edge set
  1606     ///
  1607     /// Use previously constructed edge set, and specify the edge
  1608     /// label map.
  1609     template <typename Map>
  1610     GraphReader& useEdges(const Map& map) {
  1611       checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
  1612       LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
  1613       _use_edges = true;
  1614       _writer_bits::DefaultConverter<typename Map::Value> converter;
  1615       for (EdgeIt a(_graph); a != INVALID; ++a) {
  1616         _edge_index.insert(std::make_pair(converter(map[a]), a));
  1617       }
  1618       return *this;
  1619     }
  1620 
  1621     /// \brief Use previously constructed edge set
  1622     ///
  1623     /// Use previously constructed edge set, and specify the edge
  1624     /// label map and a functor which converts the label map values to
  1625     /// \c std::string.
  1626     template <typename Map, typename Converter>
  1627     GraphReader& useEdges(const Map& map,
  1628                             const Converter& converter = Converter()) {
  1629       checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
  1630       LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
  1631       _use_edges = true;
  1632       for (EdgeIt a(_graph); a != INVALID; ++a) {
  1633         _edge_index.insert(std::make_pair(converter(map[a]), a));
  1634       }
  1635       return *this;
  1636     }
  1637 
  1638     /// \brief Skip the reading of node section
  1639     ///
  1640     /// Omit the reading of the node section. This implies that each node
  1641     /// map reading rule will be abandoned, and the nodes of the graph
  1642     /// will not be constructed, which usually cause that the edge set
  1643     /// could not be read due to lack of node name
  1644     /// could not be read due to lack of node name resolving.
  1645     /// Therefore \c skipEdges() function should also be used, or
  1646     /// \c useNodes() should be used to specify the label of the nodes.
  1647     GraphReader& skipNodes() {
  1648       LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
  1649       _skip_nodes = true;
  1650       return *this;
  1651     }
  1652 
  1653     /// \brief Skip the reading of edge section
  1654     ///
  1655     /// Omit the reading of the edge section. This implies that each edge
  1656     /// map reading rule will be abandoned, and the edges of the graph
  1657     /// will not be constructed.
  1658     GraphReader& skipEdges() {
  1659       LEMON_ASSERT(!_skip_edges, "Skip edges already set");
  1660       _skip_edges = true;
  1661       return *this;
  1662     }
  1663 
  1664     /// @}
  1665 
  1666   private:
  1667 
  1668     bool readLine() {
  1669       std::string str;
  1670       while(++line_num, std::getline(*_is, str)) {
  1671         line.clear(); line.str(str);
  1672         char c;
  1673         if (line >> std::ws >> c && c != '#') {
  1674           line.putback(c);
  1675           return true;
  1676         }
  1677       }
  1678       return false;
  1679     }
  1680 
  1681     bool readSuccess() {
  1682       return static_cast<bool>(*_is);
  1683     }
  1684 
  1685     void skipSection() {
  1686       char c;
  1687       while (readSuccess() && line >> c && c != '@') {
  1688         readLine();
  1689       }
  1690       line.putback(c);
  1691     }
  1692 
  1693     void readNodes() {
  1694 
  1695       std::vector<int> map_index(_node_maps.size());
  1696       int map_num, label_index;
  1697 
  1698       char c;
  1699       if (!readLine() || !(line >> c) || c == '@') {
  1700         if (readSuccess() && line) line.putback(c);
  1701         if (!_node_maps.empty())
  1702           throw FormatError("Cannot find map names");
  1703         return;
  1704       }
  1705       line.putback(c);
  1706 
  1707       {
  1708         std::map<std::string, int> maps;
  1709 
  1710         std::string map;
  1711         int index = 0;
  1712         while (_reader_bits::readToken(line, map)) {
  1713           if (maps.find(map) != maps.end()) {
  1714             std::ostringstream msg;
  1715             msg << "Multiple occurence of node map: " << map;
  1716             throw FormatError(msg.str());
  1717           }
  1718           maps.insert(std::make_pair(map, index));
  1719           ++index;
  1720         }
  1721 
  1722         for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
  1723           std::map<std::string, int>::iterator jt =
  1724             maps.find(_node_maps[i].first);
  1725           if (jt == maps.end()) {
  1726             std::ostringstream msg;
  1727             msg << "Map not found: " << _node_maps[i].first;
  1728             throw FormatError(msg.str());
  1729           }
  1730           map_index[i] = jt->second;
  1731         }
  1732 
  1733         {
  1734           std::map<std::string, int>::iterator jt = maps.find("label");
  1735           if (jt != maps.end()) {
  1736             label_index = jt->second;
  1737           } else {
  1738             label_index = -1;
  1739           }
  1740         }
  1741         map_num = maps.size();
  1742       }
  1743 
  1744       while (readLine() && line >> c && c != '@') {
  1745         line.putback(c);
  1746 
  1747         std::vector<std::string> tokens(map_num);
  1748         for (int i = 0; i < map_num; ++i) {
  1749           if (!_reader_bits::readToken(line, tokens[i])) {
  1750             std::ostringstream msg;
  1751             msg << "Column not found (" << i + 1 << ")";
  1752             throw FormatError(msg.str());
  1753           }
  1754         }
  1755         if (line >> std::ws >> c)
  1756           throw FormatError("Extra character at the end of line");
  1757 
  1758         Node n;
  1759         if (!_use_nodes) {
  1760           n = _graph.addNode();
  1761           if (label_index != -1)
  1762             _node_index.insert(std::make_pair(tokens[label_index], n));
  1763         } else {
  1764           if (label_index == -1)
  1765             throw FormatError("Label map not found");
  1766           typename std::map<std::string, Node>::iterator it =
  1767             _node_index.find(tokens[label_index]);
  1768           if (it == _node_index.end()) {
  1769             std::ostringstream msg;
  1770             msg << "Node with label not found: " << tokens[label_index];
  1771             throw FormatError(msg.str());
  1772           }
  1773           n = it->second;
  1774         }
  1775 
  1776         for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
  1777           _node_maps[i].second->set(n, tokens[map_index[i]]);
  1778         }
  1779 
  1780       }
  1781       if (readSuccess()) {
  1782         line.putback(c);
  1783       }
  1784     }
  1785 
  1786     void readEdges() {
  1787 
  1788       std::vector<int> map_index(_edge_maps.size());
  1789       int map_num, label_index;
  1790 
  1791       char c;
  1792       if (!readLine() || !(line >> c) || c == '@') {
  1793         if (readSuccess() && line) line.putback(c);
  1794         if (!_edge_maps.empty())
  1795           throw FormatError("Cannot find map names");
  1796         return;
  1797       }
  1798       line.putback(c);
  1799 
  1800       {
  1801         std::map<std::string, int> maps;
  1802 
  1803         std::string map;
  1804         int index = 0;
  1805         while (_reader_bits::readToken(line, map)) {
  1806           if (maps.find(map) != maps.end()) {
  1807             std::ostringstream msg;
  1808             msg << "Multiple occurence of edge map: " << map;
  1809             throw FormatError(msg.str());
  1810           }
  1811           maps.insert(std::make_pair(map, index));
  1812           ++index;
  1813         }
  1814 
  1815         for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
  1816           std::map<std::string, int>::iterator jt =
  1817             maps.find(_edge_maps[i].first);
  1818           if (jt == maps.end()) {
  1819             std::ostringstream msg;
  1820             msg << "Map not found: " << _edge_maps[i].first;
  1821             throw FormatError(msg.str());
  1822           }
  1823           map_index[i] = jt->second;
  1824         }
  1825 
  1826         {
  1827           std::map<std::string, int>::iterator jt = maps.find("label");
  1828           if (jt != maps.end()) {
  1829             label_index = jt->second;
  1830           } else {
  1831             label_index = -1;
  1832           }
  1833         }
  1834         map_num = maps.size();
  1835       }
  1836 
  1837       while (readLine() && line >> c && c != '@') {
  1838         line.putback(c);
  1839 
  1840         std::string source_token;
  1841         std::string target_token;
  1842 
  1843         if (!_reader_bits::readToken(line, source_token))
  1844           throw FormatError("Node u not found");
  1845 
  1846         if (!_reader_bits::readToken(line, target_token))
  1847           throw FormatError("Node v not found");
  1848 
  1849         std::vector<std::string> tokens(map_num);
  1850         for (int i = 0; i < map_num; ++i) {
  1851           if (!_reader_bits::readToken(line, tokens[i])) {
  1852             std::ostringstream msg;
  1853             msg << "Column not found (" << i + 1 << ")";
  1854             throw FormatError(msg.str());
  1855           }
  1856         }
  1857         if (line >> std::ws >> c)
  1858           throw FormatError("Extra character at the end of line");
  1859 
  1860         Edge e;
  1861         if (!_use_edges) {
  1862 
  1863           typename NodeIndex::iterator it;
  1864 
  1865           it = _node_index.find(source_token);
  1866           if (it == _node_index.end()) {
  1867             std::ostringstream msg;
  1868             msg << "Item not found: " << source_token;
  1869             throw FormatError(msg.str());
  1870           }
  1871           Node source = it->second;
  1872 
  1873           it = _node_index.find(target_token);
  1874           if (it == _node_index.end()) {
  1875             std::ostringstream msg;
  1876             msg << "Item not found: " << target_token;
  1877             throw FormatError(msg.str());
  1878           }
  1879           Node target = it->second;
  1880 
  1881           e = _graph.addEdge(source, target);
  1882           if (label_index != -1)
  1883             _edge_index.insert(std::make_pair(tokens[label_index], e));
  1884         } else {
  1885           if (label_index == -1)
  1886             throw FormatError("Label map not found");
  1887           typename std::map<std::string, Edge>::iterator it =
  1888             _edge_index.find(tokens[label_index]);
  1889           if (it == _edge_index.end()) {
  1890             std::ostringstream msg;
  1891             msg << "Edge with label not found: " << tokens[label_index];
  1892             throw FormatError(msg.str());
  1893           }
  1894           e = it->second;
  1895         }
  1896 
  1897         for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
  1898           _edge_maps[i].second->set(e, tokens[map_index[i]]);
  1899         }
  1900 
  1901       }
  1902       if (readSuccess()) {
  1903         line.putback(c);
  1904       }
  1905     }
  1906 
  1907     void readAttributes() {
  1908 
  1909       std::set<std::string> read_attr;
  1910 
  1911       char c;
  1912       while (readLine() && line >> c && c != '@') {
  1913         line.putback(c);
  1914 
  1915         std::string attr, token;
  1916         if (!_reader_bits::readToken(line, attr))
  1917           throw FormatError("Attribute name not found");
  1918         if (!_reader_bits::readToken(line, token))
  1919           throw FormatError("Attribute value not found");
  1920         if (line >> c)
  1921           throw FormatError("Extra character at the end of line");
  1922 
  1923         {
  1924           std::set<std::string>::iterator it = read_attr.find(attr);
  1925           if (it != read_attr.end()) {
  1926             std::ostringstream msg;
  1927             msg << "Multiple occurence of attribute: " << attr;
  1928             throw FormatError(msg.str());
  1929           }
  1930           read_attr.insert(attr);
  1931         }
  1932 
  1933         {
  1934           typename Attributes::iterator it = _attributes.lower_bound(attr);
  1935           while (it != _attributes.end() && it->first == attr) {
  1936             it->second->set(token);
  1937             ++it;
  1938           }
  1939         }
  1940 
  1941       }
  1942       if (readSuccess()) {
  1943         line.putback(c);
  1944       }
  1945       for (typename Attributes::iterator it = _attributes.begin();
  1946            it != _attributes.end(); ++it) {
  1947         if (read_attr.find(it->first) == read_attr.end()) {
  1948           std::ostringstream msg;
  1949           msg << "Attribute not found: " << it->first;
  1950           throw FormatError(msg.str());
  1951         }
  1952       }
  1953     }
  1954 
  1955   public:
  1956 
  1957     /// \name Execution of the reader
  1958     /// @{
  1959 
  1960     /// \brief Start the batch processing
  1961     ///
  1962     /// This function starts the batch processing
  1963     void run() {
  1964 
  1965       LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
  1966 
  1967       bool nodes_done = _skip_nodes;
  1968       bool edges_done = _skip_edges;
  1969       bool attributes_done = false;
  1970 
  1971       line_num = 0;
  1972       readLine();
  1973       skipSection();
  1974 
  1975       while (readSuccess()) {
  1976         try {
  1977           char c;
  1978           std::string section, caption;
  1979           line >> c;
  1980           _reader_bits::readToken(line, section);
  1981           _reader_bits::readToken(line, caption);
  1982 
  1983           if (line >> c)
  1984             throw FormatError("Extra character at the end of line");
  1985 
  1986           if (section == "nodes" && !nodes_done) {
  1987             if (_nodes_caption.empty() || _nodes_caption == caption) {
  1988               readNodes();
  1989               nodes_done = true;
  1990             }
  1991           } else if ((section == "edges" || section == "arcs") &&
  1992                      !edges_done) {
  1993             if (_edges_caption.empty() || _edges_caption == caption) {
  1994               readEdges();
  1995               edges_done = true;
  1996             }
  1997           } else if (section == "attributes" && !attributes_done) {
  1998             if (_attributes_caption.empty() || _attributes_caption == caption) {
  1999               readAttributes();
  2000               attributes_done = true;
  2001             }
  2002           } else {
  2003             readLine();
  2004             skipSection();
  2005           }
  2006         } catch (FormatError& error) {
  2007           error.line(line_num);
  2008           error.file(_filename);
  2009           throw;
  2010         }
  2011       }
  2012 
  2013       if (!nodes_done) {
  2014         throw FormatError("Section @nodes not found");
  2015       }
  2016 
  2017       if (!edges_done) {
  2018         throw FormatError("Section @edges not found");
  2019       }
  2020 
  2021       if (!attributes_done && !_attributes.empty()) {
  2022         throw FormatError("Section @attributes not found");
  2023       }
  2024 
  2025     }
  2026 
  2027     /// @}
  2028 
  2029   };
  2030 
  2031   /// \brief Return a \ref GraphReader class
  2032   ///
  2033   /// This function just returns a \ref GraphReader class.
  2034   /// \relates GraphReader
  2035   template <typename Graph>
  2036   GraphReader<Graph> graphReader(Graph& graph, std::istream& is) {
  2037     GraphReader<Graph> tmp(graph, is);
  2038     return tmp;
  2039   }
  2040 
  2041   /// \brief Return a \ref GraphReader class
  2042   ///
  2043   /// This function just returns a \ref GraphReader class.
  2044   /// \relates GraphReader
  2045   template <typename Graph>
  2046   GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {
  2047     GraphReader<Graph> tmp(graph, fn);
  2048     return tmp;
  2049   }
  2050 
  2051   /// \brief Return a \ref GraphReader class
  2052   ///
  2053   /// This function just returns a \ref GraphReader class.
  2054   /// \relates GraphReader
  2055   template <typename Graph>
  2056   GraphReader<Graph> graphReader(Graph& graph, const char* fn) {
  2057     GraphReader<Graph> tmp(graph, fn);
  2058     return tmp;
  2059   }
  2060 
  2061   class SectionReader;
  2062 
  2063   SectionReader sectionReader(std::istream& is);
  2064   SectionReader sectionReader(const std::string& fn);
  2065   SectionReader sectionReader(const char* fn);
  2066 
  2067   /// \ingroup lemon_io
  2068   ///
  2069   /// \brief Section reader class
  2070   ///
  2071   /// In the \ref lgf-format "LGF" file extra sections can be placed,
  2072   /// which contain any data in arbitrary format. Such sections can be
  2073   /// read with this class. A reading rule can be added to the class
  2074   /// with two different functions. With the \c sectionLines() function a
  2075   /// functor can process the section line-by-line, while with the \c
  2076   /// sectionStream() member the section can be read from an input
  2077   /// stream.
  2078   class SectionReader {
  2079   private:
  2080 
  2081     std::istream* _is;
  2082     bool local_is;
  2083     std::string _filename;
  2084 
  2085     typedef std::map<std::string, _reader_bits::Section*> Sections;
  2086     Sections _sections;
  2087 
  2088     int line_num;
  2089     std::istringstream line;
  2090 
  2091   public:
  2092 
  2093     /// \brief Constructor
  2094     ///
  2095     /// Construct a section reader, which reads from the given input
  2096     /// stream.
  2097     SectionReader(std::istream& is)
  2098       : _is(&is), local_is(false) {}
  2099 
  2100     /// \brief Constructor
  2101     ///
  2102     /// Construct a section reader, which reads from the given file.
  2103     SectionReader(const std::string& fn)
  2104       : _is(new std::ifstream(fn.c_str())), local_is(true),
  2105         _filename(fn) {
  2106       if (!(*_is)) {
  2107         delete _is;
  2108         throw IoError("Cannot open file", fn);
  2109       }
  2110     }
  2111 
  2112     /// \brief Constructor
  2113     ///
  2114     /// Construct a section reader, which reads from the given file.
  2115     SectionReader(const char* fn)
  2116       : _is(new std::ifstream(fn)), local_is(true),
  2117         _filename(fn) {
  2118       if (!(*_is)) {
  2119         delete _is;
  2120         throw IoError("Cannot open file", fn);
  2121       }
  2122     }
  2123 
  2124     /// \brief Destructor
  2125     ~SectionReader() {
  2126       for (Sections::iterator it = _sections.begin();
  2127            it != _sections.end(); ++it) {
  2128         delete it->second;
  2129       }
  2130 
  2131       if (local_is) {
  2132         delete _is;
  2133       }
  2134 
  2135     }
  2136 
  2137   private:
  2138 
  2139     friend SectionReader sectionReader(std::istream& is);
  2140     friend SectionReader sectionReader(const std::string& fn);
  2141     friend SectionReader sectionReader(const char* fn);
  2142 
  2143     SectionReader(SectionReader& other)
  2144       : _is(other._is), local_is(other.local_is) {
  2145 
  2146       other._is = 0;
  2147       other.local_is = false;
  2148 
  2149       _sections.swap(other._sections);
  2150     }
  2151 
  2152     SectionReader& operator=(const SectionReader&);
  2153 
  2154   public:
  2155 
  2156     /// \name Section readers
  2157     /// @{
  2158 
  2159     /// \brief Add a section processor with line oriented reading
  2160     ///
  2161     /// The first parameter is the type descriptor of the section, the
  2162     /// second is a functor, which takes just one \c std::string
  2163     /// parameter. At the reading process, each line of the section
  2164     /// will be given to the functor object. However, the empty lines
  2165     /// and the comment lines are filtered out, and the leading
  2166     /// whitespaces are trimmed from each processed string.
  2167     ///
  2168     /// For example let's see a section, which contain several
  2169     /// integers, which should be inserted into a vector.
  2170     ///\code
  2171     ///  @numbers
  2172     ///  12 45 23
  2173     ///  4
  2174     ///  23 6
  2175     ///\endcode
  2176     ///
  2177     /// The functor is implemented as a struct:
  2178     ///\code
  2179     ///  struct NumberSection {
  2180     ///    std::vector<int>& _data;
  2181     ///    NumberSection(std::vector<int>& data) : _data(data) {}
  2182     ///    void operator()(const std::string& line) {
  2183     ///      std::istringstream ls(line);
  2184     ///      int value;
  2185     ///      while (ls >> value) _data.push_back(value);
  2186     ///    }
  2187     ///  };
  2188     ///
  2189     ///  // ...
  2190     ///
  2191     ///  reader.sectionLines("numbers", NumberSection(vec));
  2192     ///\endcode
  2193     template <typename Functor>
  2194     SectionReader& sectionLines(const std::string& type, Functor functor) {
  2195       LEMON_ASSERT(!type.empty(), "Type is empty.");
  2196       LEMON_ASSERT(_sections.find(type) == _sections.end(),
  2197                    "Multiple reading of section.");
  2198       _sections.insert(std::make_pair(type,
  2199         new _reader_bits::LineSection<Functor>(functor)));
  2200       return *this;
  2201     }
  2202 
  2203 
  2204     /// \brief Add a section processor with stream oriented reading
  2205     ///
  2206     /// The first parameter is the type of the section, the second is
  2207     /// a functor, which takes an \c std::istream& and an \c int&
  2208     /// parameter, the latter regard to the line number of stream. The
  2209     /// functor can read the input while the section go on, and the
  2210     /// line number should be modified accordingly.
  2211     template <typename Functor>
  2212     SectionReader& sectionStream(const std::string& type, Functor functor) {
  2213       LEMON_ASSERT(!type.empty(), "Type is empty.");
  2214       LEMON_ASSERT(_sections.find(type) == _sections.end(),
  2215                    "Multiple reading of section.");
  2216       _sections.insert(std::make_pair(type,
  2217          new _reader_bits::StreamSection<Functor>(functor)));
  2218       return *this;
  2219     }
  2220 
  2221     /// @}
  2222 
  2223   private:
  2224 
  2225     bool readLine() {
  2226       std::string str;
  2227       while(++line_num, std::getline(*_is, str)) {
  2228         line.clear(); line.str(str);
  2229         char c;
  2230         if (line >> std::ws >> c && c != '#') {
  2231           line.putback(c);
  2232           return true;
  2233         }
  2234       }
  2235       return false;
  2236     }
  2237 
  2238     bool readSuccess() {
  2239       return static_cast<bool>(*_is);
  2240     }
  2241 
  2242     void skipSection() {
  2243       char c;
  2244       while (readSuccess() && line >> c && c != '@') {
  2245         readLine();
  2246       }
  2247       line.putback(c);
  2248     }
  2249 
  2250   public:
  2251 
  2252 
  2253     /// \name Execution of the reader
  2254     /// @{
  2255 
  2256     /// \brief Start the batch processing
  2257     ///
  2258     /// This function starts the batch processing.
  2259     void run() {
  2260 
  2261       LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
  2262 
  2263       std::set<std::string> extra_sections;
  2264 
  2265       line_num = 0;
  2266       readLine();
  2267       skipSection();
  2268 
  2269       while (readSuccess()) {
  2270         try {
  2271           char c;
  2272           std::string section, caption;
  2273           line >> c;
  2274           _reader_bits::readToken(line, section);
  2275           _reader_bits::readToken(line, caption);
  2276 
  2277           if (line >> c)
  2278             throw FormatError("Extra character at the end of line");
  2279 
  2280           if (extra_sections.find(section) != extra_sections.end()) {
  2281             std::ostringstream msg;
  2282             msg << "Multiple occurence of section: " << section;
  2283             throw FormatError(msg.str());
  2284           }
  2285           Sections::iterator it = _sections.find(section);
  2286           if (it != _sections.end()) {
  2287             extra_sections.insert(section);
  2288             it->second->process(*_is, line_num);
  2289           }
  2290           readLine();
  2291           skipSection();
  2292         } catch (FormatError& error) {
  2293           error.line(line_num);
  2294           error.file(_filename);
  2295           throw;
  2296         }
  2297       }
  2298       for (Sections::iterator it = _sections.begin();
  2299            it != _sections.end(); ++it) {
  2300         if (extra_sections.find(it->first) == extra_sections.end()) {
  2301           std::ostringstream os;
  2302           os << "Cannot find section: " << it->first;
  2303           throw FormatError(os.str());
  2304         }
  2305       }
  2306     }
  2307 
  2308     /// @}
  2309 
  2310   };
  2311 
  2312   /// \brief Return a \ref SectionReader class
  2313   ///
  2314   /// This function just returns a \ref SectionReader class.
  2315   /// \relates SectionReader
  2316   inline SectionReader sectionReader(std::istream& is) {
  2317     SectionReader tmp(is);
  2318     return tmp;
  2319   }
  2320 
  2321   /// \brief Return a \ref SectionReader class
  2322   ///
  2323   /// This function just returns a \ref SectionReader class.
  2324   /// \relates SectionReader
  2325   inline SectionReader sectionReader(const std::string& fn) {
  2326     SectionReader tmp(fn);
  2327     return tmp;
  2328   }
  2329 
  2330   /// \brief Return a \ref SectionReader class
  2331   ///
  2332   /// This function just returns a \ref SectionReader class.
  2333   /// \relates SectionReader
  2334   inline SectionReader sectionReader(const char* fn) {
  2335     SectionReader tmp(fn);
  2336     return tmp;
  2337   }
  2338 
  2339   /// \ingroup lemon_io
  2340   ///
  2341   /// \brief Reader for the contents of the \ref lgf-format "LGF" file
  2342   ///
  2343   /// This class can be used to read the sections, the map names and
  2344   /// the attributes from a file. Usually, the LEMON programs know
  2345   /// that, which type of graph, which maps and which attributes
  2346   /// should be read from a file, but in general tools (like glemon)
  2347   /// the contents of an LGF file should be guessed somehow. This class
  2348   /// reads the graph and stores the appropriate information for
  2349   /// reading the graph.
  2350   ///
  2351   ///\code
  2352   /// LgfContents contents("graph.lgf");
  2353   /// contents.run();
  2354   ///
  2355   /// // Does it contain any node section and arc section?
  2356   /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
  2357   ///   std::cerr << "Failure, cannot find graph." << std::endl;
  2358   ///   return -1;
  2359   /// }
  2360   /// std::cout << "The name of the default node section: "
  2361   ///           << contents.nodeSection(0) << std::endl;
  2362   /// std::cout << "The number of the arc maps: "
  2363   ///           << contents.arcMaps(0).size() << std::endl;
  2364   /// std::cout << "The name of second arc map: "
  2365   ///           << contents.arcMaps(0)[1] << std::endl;
  2366   ///\endcode
  2367   class LgfContents {
  2368   private:
  2369 
  2370     std::istream* _is;
  2371     bool local_is;
  2372 
  2373     std::vector<std::string> _node_sections;
  2374     std::vector<std::string> _edge_sections;
  2375     std::vector<std::string> _attribute_sections;
  2376     std::vector<std::string> _extra_sections;
  2377 
  2378     std::vector<bool> _arc_sections;
  2379 
  2380     std::vector<std::vector<std::string> > _node_maps;
  2381     std::vector<std::vector<std::string> > _edge_maps;
  2382 
  2383     std::vector<std::vector<std::string> > _attributes;
  2384 
  2385 
  2386     int line_num;
  2387     std::istringstream line;
  2388 
  2389   public:
  2390 
  2391     /// \brief Constructor
  2392     ///
  2393     /// Construct an \e LGF contents reader, which reads from the given
  2394     /// input stream.
  2395     LgfContents(std::istream& is)
  2396       : _is(&is), local_is(false) {}
  2397 
  2398     /// \brief Constructor
  2399     ///
  2400     /// Construct an \e LGF contents reader, which reads from the given
  2401     /// file.
  2402     LgfContents(const std::string& fn)
  2403       : _is(new std::ifstream(fn.c_str())), local_is(true) {
  2404       if (!(*_is)) {
  2405         delete _is;
  2406         throw IoError("Cannot open file", fn);
  2407       }
  2408     }
  2409 
  2410     /// \brief Constructor
  2411     ///
  2412     /// Construct an \e LGF contents reader, which reads from the given
  2413     /// file.
  2414     LgfContents(const char* fn)
  2415       : _is(new std::ifstream(fn)), local_is(true) {
  2416       if (!(*_is)) {
  2417         delete _is;
  2418         throw IoError("Cannot open file", fn);
  2419       }
  2420     }
  2421 
  2422     /// \brief Destructor
  2423     ~LgfContents() {
  2424       if (local_is) delete _is;
  2425     }
  2426 
  2427   private:
  2428 
  2429     LgfContents(const LgfContents&);
  2430     LgfContents& operator=(const LgfContents&);
  2431 
  2432   public:
  2433 
  2434 
  2435     /// \name Node sections
  2436     /// @{
  2437 
  2438     /// \brief Gives back the number of node sections in the file.
  2439     ///
  2440     /// Gives back the number of node sections in the file.
  2441     int nodeSectionNum() const {
  2442       return _node_sections.size();
  2443     }
  2444 
  2445     /// \brief Returns the node section name at the given position.
  2446     ///
  2447     /// Returns the node section name at the given position.
  2448     const std::string& nodeSection(int i) const {
  2449       return _node_sections[i];
  2450     }
  2451 
  2452     /// \brief Gives back the node maps for the given section.
  2453     ///
  2454     /// Gives back the node maps for the given section.
  2455     const std::vector<std::string>& nodeMapNames(int i) const {
  2456       return _node_maps[i];
  2457     }
  2458 
  2459     /// @}
  2460 
  2461     /// \name Arc/Edge sections
  2462     /// @{
  2463 
  2464     /// \brief Gives back the number of arc/edge sections in the file.
  2465     ///
  2466     /// Gives back the number of arc/edge sections in the file.
  2467     /// \note It is synonym of \c edgeSectionNum().
  2468     int arcSectionNum() const {
  2469       return _edge_sections.size();
  2470     }
  2471 
  2472     /// \brief Returns the arc/edge section name at the given position.
  2473     ///
  2474     /// Returns the arc/edge section name at the given position.
  2475     /// \note It is synonym of \c edgeSection().
  2476     const std::string& arcSection(int i) const {
  2477       return _edge_sections[i];
  2478     }
  2479 
  2480     /// \brief Gives back the arc/edge maps for the given section.
  2481     ///
  2482     /// Gives back the arc/edge maps for the given section.
  2483     /// \note It is synonym of \c edgeMapNames().
  2484     const std::vector<std::string>& arcMapNames(int i) const {
  2485       return _edge_maps[i];
  2486     }
  2487 
  2488     /// @}
  2489 
  2490     /// \name Synonyms
  2491     /// @{
  2492 
  2493     /// \brief Gives back the number of arc/edge sections in the file.
  2494     ///
  2495     /// Gives back the number of arc/edge sections in the file.
  2496     /// \note It is synonym of \c arcSectionNum().
  2497     int edgeSectionNum() const {
  2498       return _edge_sections.size();
  2499     }
  2500 
  2501     /// \brief Returns the section name at the given position.
  2502     ///
  2503     /// Returns the section name at the given position.
  2504     /// \note It is synonym of \c arcSection().
  2505     const std::string& edgeSection(int i) const {
  2506       return _edge_sections[i];
  2507     }
  2508 
  2509     /// \brief Gives back the edge maps for the given section.
  2510     ///
  2511     /// Gives back the edge maps for the given section.
  2512     /// \note It is synonym of \c arcMapNames().
  2513     const std::vector<std::string>& edgeMapNames(int i) const {
  2514       return _edge_maps[i];
  2515     }
  2516 
  2517     /// @}
  2518 
  2519     /// \name Attribute sections
  2520     /// @{
  2521 
  2522     /// \brief Gives back the number of attribute sections in the file.
  2523     ///
  2524     /// Gives back the number of attribute sections in the file.
  2525     int attributeSectionNum() const {
  2526       return _attribute_sections.size();
  2527     }
  2528 
  2529     /// \brief Returns the attribute section name at the given position.
  2530     ///
  2531     /// Returns the attribute section name at the given position.
  2532     const std::string& attributeSectionNames(int i) const {
  2533       return _attribute_sections[i];
  2534     }
  2535 
  2536     /// \brief Gives back the attributes for the given section.
  2537     ///
  2538     /// Gives back the attributes for the given section.
  2539     const std::vector<std::string>& attributes(int i) const {
  2540       return _attributes[i];
  2541     }
  2542 
  2543     /// @}
  2544 
  2545     /// \name Extra sections
  2546     /// @{
  2547 
  2548     /// \brief Gives back the number of extra sections in the file.
  2549     ///
  2550     /// Gives back the number of extra sections in the file.
  2551     int extraSectionNum() const {
  2552       return _extra_sections.size();
  2553     }
  2554 
  2555     /// \brief Returns the extra section type at the given position.
  2556     ///
  2557     /// Returns the section type at the given position.
  2558     const std::string& extraSection(int i) const {
  2559       return _extra_sections[i];
  2560     }
  2561 
  2562     /// @}
  2563 
  2564   private:
  2565 
  2566     bool readLine() {
  2567       std::string str;
  2568       while(++line_num, std::getline(*_is, str)) {
  2569         line.clear(); line.str(str);
  2570         char c;
  2571         if (line >> std::ws >> c && c != '#') {
  2572           line.putback(c);
  2573           return true;
  2574         }
  2575       }
  2576       return false;
  2577     }
  2578 
  2579     bool readSuccess() {
  2580       return static_cast<bool>(*_is);
  2581     }
  2582 
  2583     void skipSection() {
  2584       char c;
  2585       while (readSuccess() && line >> c && c != '@') {
  2586         readLine();
  2587       }
  2588       line.putback(c);
  2589     }
  2590 
  2591     void readMaps(std::vector<std::string>& maps) {
  2592       char c;
  2593       if (!readLine() || !(line >> c) || c == '@') {
  2594         if (readSuccess() && line) line.putback(c);
  2595         return;
  2596       }
  2597       line.putback(c);
  2598       std::string map;
  2599       while (_reader_bits::readToken(line, map)) {
  2600         maps.push_back(map);
  2601       }
  2602     }
  2603 
  2604     void readAttributes(std::vector<std::string>& attrs) {
  2605       readLine();
  2606       char c;
  2607       while (readSuccess() && line >> c && c != '@') {
  2608         line.putback(c);
  2609         std::string attr;
  2610         _reader_bits::readToken(line, attr);
  2611         attrs.push_back(attr);
  2612         readLine();
  2613       }
  2614       line.putback(c);
  2615     }
  2616 
  2617   public:
  2618 
  2619     /// \name Execution of the contents reader
  2620     /// @{
  2621 
  2622     /// \brief Starts the reading
  2623     ///
  2624     /// This function starts the reading.
  2625     void run() {
  2626 
  2627       readLine();
  2628       skipSection();
  2629 
  2630       while (readSuccess()) {
  2631 
  2632         char c;
  2633         line >> c;
  2634 
  2635         std::string section, caption;
  2636         _reader_bits::readToken(line, section);
  2637         _reader_bits::readToken(line, caption);
  2638 
  2639         if (section == "nodes") {
  2640           _node_sections.push_back(caption);
  2641           _node_maps.push_back(std::vector<std::string>());
  2642           readMaps(_node_maps.back());
  2643           readLine(); skipSection();
  2644         } else if (section == "arcs" || section == "edges") {
  2645           _edge_sections.push_back(caption);
  2646           _arc_sections.push_back(section == "arcs");
  2647           _edge_maps.push_back(std::vector<std::string>());
  2648           readMaps(_edge_maps.back());
  2649           readLine(); skipSection();
  2650         } else if (section == "attributes") {
  2651           _attribute_sections.push_back(caption);
  2652           _attributes.push_back(std::vector<std::string>());
  2653           readAttributes(_attributes.back());
  2654         } else {
  2655           _extra_sections.push_back(section);
  2656           readLine(); skipSection();
  2657         }
  2658       }
  2659     }
  2660 
  2661     /// @}
  2662 
  2663   };
  2664 }
  2665 
  2666 #endif