lemon/lgf_reader.h
author Alpar Juttner <alpar@cs.elte.hu>
Mon, 24 Oct 2011 21:42:22 +0200
changeset 956 4dd3dc8eb5a7
parent 877 141f9c0db4a3
parent 949 54464584b157
child 966 c8fce9beb46a
permissions -rw-r--r--
Merge #428 and #429
     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) 2003-2011
     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 _GR, bool _dir, typename _Map,
   105               typename _Converter = DefaultConverter<typename _Map::Value> >
   106     class GraphArcMapStorage : public MapStorageBase<typename _GR::Edge> {
   107     public:
   108       typedef _Map Map;
   109       typedef _Converter Converter;
   110       typedef _GR GR;
   111       typedef typename GR::Edge Item;
   112       static const bool dir = _dir;
   113 
   114     private:
   115       const GR& _graph;
   116       Map& _map;
   117       Converter _converter;
   118 
   119     public:
   120       GraphArcMapStorage(const GR& 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 GR>
   177     struct GraphArcLookUpConverter {
   178       const GR& _graph;
   179       const std::map<std::string, typename GR::Edge>& _map;
   180 
   181       GraphArcLookUpConverter(const GR& graph,
   182                               const std::map<std::string,
   183                                              typename GR::Edge>& map)
   184         : _graph(graph), _map(map) {}
   185 
   186       typename GR::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 GR::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 DGR>
   391   class DigraphReader;
   392 
   393   template <typename TDGR>
   394   DigraphReader<TDGR> digraphReader(TDGR& digraph, std::istream& is = std::cin);
   395   template <typename TDGR>
   396   DigraphReader<TDGR> digraphReader(TDGR& digraph, const std::string& fn);
   397   template <typename TDGR>
   398   DigraphReader<TDGR> digraphReader(TDGR& digraph, const char *fn);
   399 
   400   /// \ingroup lemon_io
   401   ///
   402   /// \brief \ref lgf-format "LGF" reader for directed graphs
   403   ///
   404   /// This utility reads an \ref lgf-format "LGF" file.
   405   ///
   406   /// The reading method does a batch processing. The user creates a
   407   /// reader object, then various reading rules can be added to the
   408   /// reader, and eventually the reading is executed with the \c run()
   409   /// member function. A map reading rule can be added to the reader
   410   /// with the \c nodeMap() or \c arcMap() members. An optional
   411   /// converter parameter can also be added as a standard functor
   412   /// converting from \c std::string to the value type of the map. If it
   413   /// is set, it will determine how the tokens in the file should be
   414   /// converted to the value type of the map. If the functor is not set,
   415   /// then a default conversion will be used. One map can be read into
   416   /// multiple map objects at the same time. The \c attribute(), \c
   417   /// node() and \c arc() functions are used to add attribute reading
   418   /// rules.
   419   ///
   420   ///\code
   421   /// DigraphReader<DGR>(digraph, std::cin).
   422   ///   nodeMap("coordinates", coord_map).
   423   ///   arcMap("capacity", cap_map).
   424   ///   node("source", src).
   425   ///   node("target", trg).
   426   ///   attribute("caption", caption).
   427   ///   run();
   428   ///\endcode
   429   ///
   430   /// By default, the reader uses the first section in the file of the
   431   /// proper type. If a section has an optional name, then it can be
   432   /// selected for reading by giving an optional name parameter to the
   433   /// \c nodes(), \c arcs() or \c attributes() functions.
   434   ///
   435   /// The \c useNodes() and \c useArcs() functions are used to tell the reader
   436   /// that the nodes or arcs should not be constructed (added to the
   437   /// graph) during the reading, but instead the label map of the items
   438   /// are given as a parameter of these functions. An
   439   /// application of these functions is multipass reading, which is
   440   /// important if two \c \@arcs sections must be read from the
   441   /// file. In this case the first phase would read the node set and one
   442   /// of the arc sets, while the second phase would read the second arc
   443   /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
   444   /// The previously read label node map should be passed to the \c
   445   /// useNodes() functions. Another application of multipass reading when
   446   /// paths are given as a node map or an arc map.
   447   /// It is impossible to read this in
   448   /// a single pass, because the arcs are not constructed when the node
   449   /// maps are read.
   450   template <typename DGR>
   451   class DigraphReader {
   452   public:
   453 
   454     typedef DGR Digraph;
   455 
   456   private:
   457 
   458     TEMPLATE_DIGRAPH_TYPEDEFS(DGR);
   459 
   460     std::istream* _is;
   461     bool local_is;
   462     std::string _filename;
   463 
   464     DGR& _digraph;
   465 
   466     std::string _nodes_caption;
   467     std::string _arcs_caption;
   468     std::string _attributes_caption;
   469 
   470     typedef std::map<std::string, Node> NodeIndex;
   471     NodeIndex _node_index;
   472     typedef std::map<std::string, Arc> ArcIndex;
   473     ArcIndex _arc_index;
   474 
   475     typedef std::vector<std::pair<std::string,
   476       _reader_bits::MapStorageBase<Node>*> > NodeMaps;
   477     NodeMaps _node_maps;
   478 
   479     typedef std::vector<std::pair<std::string,
   480       _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
   481     ArcMaps _arc_maps;
   482 
   483     typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
   484       Attributes;
   485     Attributes _attributes;
   486 
   487     bool _use_nodes;
   488     bool _use_arcs;
   489 
   490     bool _skip_nodes;
   491     bool _skip_arcs;
   492 
   493     int line_num;
   494     std::istringstream line;
   495 
   496   public:
   497 
   498     /// \brief Constructor
   499     ///
   500     /// Construct a directed graph reader, which reads from the given
   501     /// input stream.
   502     DigraphReader(DGR& digraph, std::istream& is = std::cin)
   503       : _is(&is), local_is(false), _digraph(digraph),
   504         _use_nodes(false), _use_arcs(false),
   505         _skip_nodes(false), _skip_arcs(false) {}
   506 
   507     /// \brief Constructor
   508     ///
   509     /// Construct a directed graph reader, which reads from the given
   510     /// file.
   511     DigraphReader(DGR& digraph, const std::string& fn)
   512       : _is(new std::ifstream(fn.c_str())), local_is(true),
   513         _filename(fn), _digraph(digraph),
   514         _use_nodes(false), _use_arcs(false),
   515         _skip_nodes(false), _skip_arcs(false) {
   516       if (!(*_is)) {
   517         delete _is;
   518         throw IoError("Cannot open file", fn);
   519       }
   520     }
   521 
   522     /// \brief Constructor
   523     ///
   524     /// Construct a directed graph reader, which reads from the given
   525     /// file.
   526     DigraphReader(DGR& digraph, const char* fn)
   527       : _is(new std::ifstream(fn)), local_is(true),
   528         _filename(fn), _digraph(digraph),
   529         _use_nodes(false), _use_arcs(false),
   530         _skip_nodes(false), _skip_arcs(false) {
   531       if (!(*_is)) {
   532         delete _is;
   533         throw IoError("Cannot open file", fn);
   534       }
   535     }
   536 
   537     /// \brief Destructor
   538     ~DigraphReader() {
   539       for (typename NodeMaps::iterator it = _node_maps.begin();
   540            it != _node_maps.end(); ++it) {
   541         delete it->second;
   542       }
   543 
   544       for (typename ArcMaps::iterator it = _arc_maps.begin();
   545            it != _arc_maps.end(); ++it) {
   546         delete it->second;
   547       }
   548 
   549       for (typename Attributes::iterator it = _attributes.begin();
   550            it != _attributes.end(); ++it) {
   551         delete it->second;
   552       }
   553 
   554       if (local_is) {
   555         delete _is;
   556       }
   557 
   558     }
   559 
   560   private:
   561 
   562     template <typename TDGR>
   563     friend DigraphReader<TDGR> digraphReader(TDGR& digraph, std::istream& is);
   564     template <typename TDGR>
   565     friend DigraphReader<TDGR> digraphReader(TDGR& digraph,
   566                                              const std::string& fn);
   567     template <typename TDGR>
   568     friend DigraphReader<TDGR> digraphReader(TDGR& digraph, const char *fn);
   569 
   570     DigraphReader(DigraphReader& other)
   571       : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
   572         _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
   573         _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
   574 
   575       other._is = 0;
   576       other.local_is = false;
   577 
   578       _node_index.swap(other._node_index);
   579       _arc_index.swap(other._arc_index);
   580 
   581       _node_maps.swap(other._node_maps);
   582       _arc_maps.swap(other._arc_maps);
   583       _attributes.swap(other._attributes);
   584 
   585       _nodes_caption = other._nodes_caption;
   586       _arcs_caption = other._arcs_caption;
   587       _attributes_caption = other._attributes_caption;
   588 
   589     }
   590 
   591     DigraphReader& operator=(const DigraphReader&);
   592 
   593   public:
   594 
   595     /// \name Reading Rules
   596     /// @{
   597 
   598     /// \brief Node map reading rule
   599     ///
   600     /// Add a node map reading rule to the reader.
   601     template <typename Map>
   602     DigraphReader& nodeMap(const std::string& caption, Map& map) {
   603       checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
   604       _reader_bits::MapStorageBase<Node>* storage =
   605         new _reader_bits::MapStorage<Node, Map>(map);
   606       _node_maps.push_back(std::make_pair(caption, storage));
   607       return *this;
   608     }
   609 
   610     /// \brief Node map reading rule
   611     ///
   612     /// Add a node map reading rule with specialized converter to the
   613     /// reader.
   614     template <typename Map, typename Converter>
   615     DigraphReader& nodeMap(const std::string& caption, Map& map,
   616                            const Converter& converter = Converter()) {
   617       checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
   618       _reader_bits::MapStorageBase<Node>* storage =
   619         new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
   620       _node_maps.push_back(std::make_pair(caption, storage));
   621       return *this;
   622     }
   623 
   624     /// \brief Arc map reading rule
   625     ///
   626     /// Add an arc map reading rule to the reader.
   627     template <typename Map>
   628     DigraphReader& arcMap(const std::string& caption, Map& map) {
   629       checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
   630       _reader_bits::MapStorageBase<Arc>* storage =
   631         new _reader_bits::MapStorage<Arc, Map>(map);
   632       _arc_maps.push_back(std::make_pair(caption, storage));
   633       return *this;
   634     }
   635 
   636     /// \brief Arc map reading rule
   637     ///
   638     /// Add an arc map reading rule with specialized converter to the
   639     /// reader.
   640     template <typename Map, typename Converter>
   641     DigraphReader& arcMap(const std::string& caption, Map& map,
   642                           const Converter& converter = Converter()) {
   643       checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
   644       _reader_bits::MapStorageBase<Arc>* storage =
   645         new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
   646       _arc_maps.push_back(std::make_pair(caption, storage));
   647       return *this;
   648     }
   649 
   650     /// \brief Attribute reading rule
   651     ///
   652     /// Add an attribute reading rule to the reader.
   653     template <typename Value>
   654     DigraphReader& attribute(const std::string& caption, Value& value) {
   655       _reader_bits::ValueStorageBase* storage =
   656         new _reader_bits::ValueStorage<Value>(value);
   657       _attributes.insert(std::make_pair(caption, storage));
   658       return *this;
   659     }
   660 
   661     /// \brief Attribute reading rule
   662     ///
   663     /// Add an attribute reading rule with specialized converter to the
   664     /// reader.
   665     template <typename Value, typename Converter>
   666     DigraphReader& attribute(const std::string& caption, Value& value,
   667                              const Converter& converter = Converter()) {
   668       _reader_bits::ValueStorageBase* storage =
   669         new _reader_bits::ValueStorage<Value, Converter>(value, converter);
   670       _attributes.insert(std::make_pair(caption, storage));
   671       return *this;
   672     }
   673 
   674     /// \brief Node reading rule
   675     ///
   676     /// Add a node reading rule to reader.
   677     DigraphReader& node(const std::string& caption, Node& node) {
   678       typedef _reader_bits::MapLookUpConverter<Node> Converter;
   679       Converter converter(_node_index);
   680       _reader_bits::ValueStorageBase* storage =
   681         new _reader_bits::ValueStorage<Node, Converter>(node, converter);
   682       _attributes.insert(std::make_pair(caption, storage));
   683       return *this;
   684     }
   685 
   686     /// \brief Arc reading rule
   687     ///
   688     /// Add an arc reading rule to reader.
   689     DigraphReader& arc(const std::string& caption, Arc& arc) {
   690       typedef _reader_bits::MapLookUpConverter<Arc> Converter;
   691       Converter converter(_arc_index);
   692       _reader_bits::ValueStorageBase* storage =
   693         new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
   694       _attributes.insert(std::make_pair(caption, storage));
   695       return *this;
   696     }
   697 
   698     /// @}
   699 
   700     /// \name Select Section by Name
   701     /// @{
   702 
   703     /// \brief Set \c \@nodes section to be read
   704     ///
   705     /// Set \c \@nodes section to be read
   706     DigraphReader& nodes(const std::string& caption) {
   707       _nodes_caption = caption;
   708       return *this;
   709     }
   710 
   711     /// \brief Set \c \@arcs section to be read
   712     ///
   713     /// Set \c \@arcs section to be read
   714     DigraphReader& arcs(const std::string& caption) {
   715       _arcs_caption = caption;
   716       return *this;
   717     }
   718 
   719     /// \brief Set \c \@attributes section to be read
   720     ///
   721     /// Set \c \@attributes section to be read
   722     DigraphReader& attributes(const std::string& caption) {
   723       _attributes_caption = caption;
   724       return *this;
   725     }
   726 
   727     /// @}
   728 
   729     /// \name Using Previously Constructed Node or Arc Set
   730     /// @{
   731 
   732     /// \brief Use previously constructed node set
   733     ///
   734     /// Use previously constructed node set, and specify the node
   735     /// label map.
   736     template <typename Map>
   737     DigraphReader& useNodes(const Map& map) {
   738       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
   739       LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
   740       _use_nodes = true;
   741       _writer_bits::DefaultConverter<typename Map::Value> converter;
   742       for (NodeIt n(_digraph); n != INVALID; ++n) {
   743         _node_index.insert(std::make_pair(converter(map[n]), n));
   744       }
   745       return *this;
   746     }
   747 
   748     /// \brief Use previously constructed node set
   749     ///
   750     /// Use previously constructed node set, and specify the node
   751     /// label map and a functor which converts the label map values to
   752     /// \c std::string.
   753     template <typename Map, typename Converter>
   754     DigraphReader& useNodes(const Map& map,
   755                             const Converter& converter = Converter()) {
   756       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
   757       LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
   758       _use_nodes = true;
   759       for (NodeIt n(_digraph); n != INVALID; ++n) {
   760         _node_index.insert(std::make_pair(converter(map[n]), n));
   761       }
   762       return *this;
   763     }
   764 
   765     /// \brief Use previously constructed arc set
   766     ///
   767     /// Use previously constructed arc set, and specify the arc
   768     /// label map.
   769     template <typename Map>
   770     DigraphReader& useArcs(const Map& map) {
   771       checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
   772       LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
   773       _use_arcs = true;
   774       _writer_bits::DefaultConverter<typename Map::Value> converter;
   775       for (ArcIt a(_digraph); a != INVALID; ++a) {
   776         _arc_index.insert(std::make_pair(converter(map[a]), a));
   777       }
   778       return *this;
   779     }
   780 
   781     /// \brief Use previously constructed arc set
   782     ///
   783     /// Use previously constructed arc set, and specify the arc
   784     /// label map and a functor which converts the label map values to
   785     /// \c std::string.
   786     template <typename Map, typename Converter>
   787     DigraphReader& useArcs(const Map& map,
   788                            const Converter& converter = Converter()) {
   789       checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
   790       LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
   791       _use_arcs = true;
   792       for (ArcIt a(_digraph); a != INVALID; ++a) {
   793         _arc_index.insert(std::make_pair(converter(map[a]), a));
   794       }
   795       return *this;
   796     }
   797 
   798     /// \brief Skips the reading of node section
   799     ///
   800     /// Omit the reading of the node section. This implies that each node
   801     /// map reading rule will be abandoned, and the nodes of the graph
   802     /// will not be constructed, which usually cause that the arc set
   803     /// could not be read due to lack of node name resolving.
   804     /// Therefore \c skipArcs() function should also be used, or
   805     /// \c useNodes() should be used to specify the label of the nodes.
   806     DigraphReader& skipNodes() {
   807       LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
   808       _skip_nodes = true;
   809       return *this;
   810     }
   811 
   812     /// \brief Skips the reading of arc section
   813     ///
   814     /// Omit the reading of the arc section. This implies that each arc
   815     /// map reading rule will be abandoned, and the arcs of the graph
   816     /// will not be constructed.
   817     DigraphReader& skipArcs() {
   818       LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
   819       _skip_arcs = true;
   820       return *this;
   821     }
   822 
   823     /// @}
   824 
   825   private:
   826 
   827     bool readLine() {
   828       std::string str;
   829       while(++line_num, std::getline(*_is, str)) {
   830         line.clear(); line.str(str);
   831         char c;
   832         if (line >> std::ws >> c && c != '#') {
   833           line.putback(c);
   834           return true;
   835         }
   836       }
   837       return false;
   838     }
   839 
   840     bool readSuccess() {
   841       return static_cast<bool>(*_is);
   842     }
   843 
   844     void skipSection() {
   845       char c;
   846       while (readSuccess() && line >> c && c != '@') {
   847         readLine();
   848       }
   849       if (readSuccess()) {
   850         line.putback(c);
   851       }
   852     }
   853 
   854     void readNodes() {
   855 
   856       std::vector<int> map_index(_node_maps.size());
   857       int map_num, label_index;
   858 
   859       char c;
   860       if (!readLine() || !(line >> c) || c == '@') {
   861         if (readSuccess() && line) line.putback(c);
   862         if (!_node_maps.empty())
   863           throw FormatError("Cannot find map names");
   864         return;
   865       }
   866       line.putback(c);
   867 
   868       {
   869         std::map<std::string, int> maps;
   870 
   871         std::string map;
   872         int index = 0;
   873         while (_reader_bits::readToken(line, map)) {
   874           if (maps.find(map) != maps.end()) {
   875             std::ostringstream msg;
   876             msg << "Multiple occurence of node map: " << map;
   877             throw FormatError(msg.str());
   878           }
   879           maps.insert(std::make_pair(map, index));
   880           ++index;
   881         }
   882 
   883         for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
   884           std::map<std::string, int>::iterator jt =
   885             maps.find(_node_maps[i].first);
   886           if (jt == maps.end()) {
   887             std::ostringstream msg;
   888             msg << "Map not found: " << _node_maps[i].first;
   889             throw FormatError(msg.str());
   890           }
   891           map_index[i] = jt->second;
   892         }
   893 
   894         {
   895           std::map<std::string, int>::iterator jt = maps.find("label");
   896           if (jt != maps.end()) {
   897             label_index = jt->second;
   898           } else {
   899             label_index = -1;
   900           }
   901         }
   902         map_num = maps.size();
   903       }
   904 
   905       while (readLine() && line >> c && c != '@') {
   906         line.putback(c);
   907 
   908         std::vector<std::string> tokens(map_num);
   909         for (int i = 0; i < map_num; ++i) {
   910           if (!_reader_bits::readToken(line, tokens[i])) {
   911             std::ostringstream msg;
   912             msg << "Column not found (" << i + 1 << ")";
   913             throw FormatError(msg.str());
   914           }
   915         }
   916         if (line >> std::ws >> c)
   917           throw FormatError("Extra character at the end of line");
   918 
   919         Node n;
   920         if (!_use_nodes) {
   921           n = _digraph.addNode();
   922           if (label_index != -1)
   923             _node_index.insert(std::make_pair(tokens[label_index], n));
   924         } else {
   925           if (label_index == -1)
   926             throw FormatError("Label map not found");
   927           typename std::map<std::string, Node>::iterator it =
   928             _node_index.find(tokens[label_index]);
   929           if (it == _node_index.end()) {
   930             std::ostringstream msg;
   931             msg << "Node with label not found: " << tokens[label_index];
   932             throw FormatError(msg.str());
   933           }
   934           n = it->second;
   935         }
   936 
   937         for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
   938           _node_maps[i].second->set(n, tokens[map_index[i]]);
   939         }
   940 
   941       }
   942       if (readSuccess()) {
   943         line.putback(c);
   944       }
   945     }
   946 
   947     void readArcs() {
   948 
   949       std::vector<int> map_index(_arc_maps.size());
   950       int map_num, label_index;
   951 
   952       char c;
   953       if (!readLine() || !(line >> c) || c == '@') {
   954         if (readSuccess() && line) line.putback(c);
   955         if (!_arc_maps.empty())
   956           throw FormatError("Cannot find map names");
   957         return;
   958       }
   959       line.putback(c);
   960 
   961       {
   962         std::map<std::string, int> maps;
   963 
   964         std::string map;
   965         int index = 0;
   966         while (_reader_bits::readToken(line, map)) {
   967           if(map == "-") {
   968               if(index!=0)
   969                 throw FormatError("'-' is not allowed as a map name");
   970               else if (line >> std::ws >> c)
   971                 throw FormatError("Extra character at the end of line");
   972               else break;
   973             }
   974           if (maps.find(map) != maps.end()) {
   975             std::ostringstream msg;
   976             msg << "Multiple occurence of arc map: " << map;
   977             throw FormatError(msg.str());
   978           }
   979           maps.insert(std::make_pair(map, index));
   980           ++index;
   981         }
   982 
   983         for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
   984           std::map<std::string, int>::iterator jt =
   985             maps.find(_arc_maps[i].first);
   986           if (jt == maps.end()) {
   987             std::ostringstream msg;
   988             msg << "Map not found: " << _arc_maps[i].first;
   989             throw FormatError(msg.str());
   990           }
   991           map_index[i] = jt->second;
   992         }
   993 
   994         {
   995           std::map<std::string, int>::iterator jt = maps.find("label");
   996           if (jt != maps.end()) {
   997             label_index = jt->second;
   998           } else {
   999             label_index = -1;
  1000           }
  1001         }
  1002         map_num = maps.size();
  1003       }
  1004 
  1005       while (readLine() && line >> c && c != '@') {
  1006         line.putback(c);
  1007 
  1008         std::string source_token;
  1009         std::string target_token;
  1010 
  1011         if (!_reader_bits::readToken(line, source_token))
  1012           throw FormatError("Source not found");
  1013 
  1014         if (!_reader_bits::readToken(line, target_token))
  1015           throw FormatError("Target not found");
  1016 
  1017         std::vector<std::string> tokens(map_num);
  1018         for (int i = 0; i < map_num; ++i) {
  1019           if (!_reader_bits::readToken(line, tokens[i])) {
  1020             std::ostringstream msg;
  1021             msg << "Column not found (" << i + 1 << ")";
  1022             throw FormatError(msg.str());
  1023           }
  1024         }
  1025         if (line >> std::ws >> c)
  1026           throw FormatError("Extra character at the end of line");
  1027 
  1028         Arc a;
  1029         if (!_use_arcs) {
  1030 
  1031           typename NodeIndex::iterator it;
  1032 
  1033           it = _node_index.find(source_token);
  1034           if (it == _node_index.end()) {
  1035             std::ostringstream msg;
  1036             msg << "Item not found: " << source_token;
  1037             throw FormatError(msg.str());
  1038           }
  1039           Node source = it->second;
  1040 
  1041           it = _node_index.find(target_token);
  1042           if (it == _node_index.end()) {
  1043             std::ostringstream msg;
  1044             msg << "Item not found: " << target_token;
  1045             throw FormatError(msg.str());
  1046           }
  1047           Node target = it->second;
  1048 
  1049           a = _digraph.addArc(source, target);
  1050           if (label_index != -1)
  1051             _arc_index.insert(std::make_pair(tokens[label_index], a));
  1052         } else {
  1053           if (label_index == -1)
  1054             throw FormatError("Label map not found");
  1055           typename std::map<std::string, Arc>::iterator it =
  1056             _arc_index.find(tokens[label_index]);
  1057           if (it == _arc_index.end()) {
  1058             std::ostringstream msg;
  1059             msg << "Arc with label not found: " << tokens[label_index];
  1060             throw FormatError(msg.str());
  1061           }
  1062           a = it->second;
  1063         }
  1064 
  1065         for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
  1066           _arc_maps[i].second->set(a, tokens[map_index[i]]);
  1067         }
  1068 
  1069       }
  1070       if (readSuccess()) {
  1071         line.putback(c);
  1072       }
  1073     }
  1074 
  1075     void readAttributes() {
  1076 
  1077       std::set<std::string> read_attr;
  1078 
  1079       char c;
  1080       while (readLine() && line >> c && c != '@') {
  1081         line.putback(c);
  1082 
  1083         std::string attr, token;
  1084         if (!_reader_bits::readToken(line, attr))
  1085           throw FormatError("Attribute name not found");
  1086         if (!_reader_bits::readToken(line, token))
  1087           throw FormatError("Attribute value not found");
  1088         if (line >> c)
  1089           throw FormatError("Extra character at the end of line");
  1090 
  1091         {
  1092           std::set<std::string>::iterator it = read_attr.find(attr);
  1093           if (it != read_attr.end()) {
  1094             std::ostringstream msg;
  1095             msg << "Multiple occurence of attribute: " << attr;
  1096             throw FormatError(msg.str());
  1097           }
  1098           read_attr.insert(attr);
  1099         }
  1100 
  1101         {
  1102           typename Attributes::iterator it = _attributes.lower_bound(attr);
  1103           while (it != _attributes.end() && it->first == attr) {
  1104             it->second->set(token);
  1105             ++it;
  1106           }
  1107         }
  1108 
  1109       }
  1110       if (readSuccess()) {
  1111         line.putback(c);
  1112       }
  1113       for (typename Attributes::iterator it = _attributes.begin();
  1114            it != _attributes.end(); ++it) {
  1115         if (read_attr.find(it->first) == read_attr.end()) {
  1116           std::ostringstream msg;
  1117           msg << "Attribute not found: " << it->first;
  1118           throw FormatError(msg.str());
  1119         }
  1120       }
  1121     }
  1122 
  1123   public:
  1124 
  1125     /// \name Execution of the Reader
  1126     /// @{
  1127 
  1128     /// \brief Start the batch processing
  1129     ///
  1130     /// This function starts the batch processing
  1131     void run() {
  1132       LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
  1133 
  1134       bool nodes_done = _skip_nodes;
  1135       bool arcs_done = _skip_arcs;
  1136       bool attributes_done = false;
  1137 
  1138       line_num = 0;
  1139       readLine();
  1140       skipSection();
  1141 
  1142       while (readSuccess()) {
  1143         try {
  1144           char c;
  1145           std::string section, caption;
  1146           line >> c;
  1147           _reader_bits::readToken(line, section);
  1148           _reader_bits::readToken(line, caption);
  1149 
  1150           if (line >> c)
  1151             throw FormatError("Extra character at the end of line");
  1152 
  1153           if (section == "nodes" && !nodes_done) {
  1154             if (_nodes_caption.empty() || _nodes_caption == caption) {
  1155               readNodes();
  1156               nodes_done = true;
  1157             }
  1158           } else if ((section == "arcs" || section == "edges") &&
  1159                      !arcs_done) {
  1160             if (_arcs_caption.empty() || _arcs_caption == caption) {
  1161               readArcs();
  1162               arcs_done = true;
  1163             }
  1164           } else if (section == "attributes" && !attributes_done) {
  1165             if (_attributes_caption.empty() || _attributes_caption == caption) {
  1166               readAttributes();
  1167               attributes_done = true;
  1168             }
  1169           } else {
  1170             readLine();
  1171             skipSection();
  1172           }
  1173         } catch (FormatError& error) {
  1174           error.line(line_num);
  1175           error.file(_filename);
  1176           throw;
  1177         }
  1178       }
  1179 
  1180       if (!nodes_done) {
  1181         throw FormatError("Section @nodes not found");
  1182       }
  1183 
  1184       if (!arcs_done) {
  1185         throw FormatError("Section @arcs not found");
  1186       }
  1187 
  1188       if (!attributes_done && !_attributes.empty()) {
  1189         throw FormatError("Section @attributes not found");
  1190       }
  1191 
  1192     }
  1193 
  1194     /// @}
  1195 
  1196   };
  1197 
  1198   /// \ingroup lemon_io
  1199   ///
  1200   /// \brief Return a \ref DigraphReader class
  1201   ///
  1202   /// This function just returns a \ref DigraphReader class.
  1203   ///
  1204   /// With this function a digraph can be read from an
  1205   /// \ref lgf-format "LGF" file or input stream with several maps and
  1206   /// attributes. For example, there is network flow problem on a
  1207   /// digraph, i.e. a digraph with a \e capacity map on the arcs and
  1208   /// \e source and \e target nodes. This digraph can be read with the
  1209   /// following code:
  1210   ///
  1211   ///\code
  1212   ///ListDigraph digraph;
  1213   ///ListDigraph::ArcMap<int> cm(digraph);
  1214   ///ListDigraph::Node src, trg;
  1215   ///digraphReader(digraph, std::cin).
  1216   ///  arcMap("capacity", cap).
  1217   ///  node("source", src).
  1218   ///  node("target", trg).
  1219   ///  run();
  1220   ///\endcode
  1221   ///
  1222   /// For a complete documentation, please see the \ref DigraphReader
  1223   /// class documentation.
  1224   /// \warning Don't forget to put the \ref DigraphReader::run() "run()"
  1225   /// to the end of the parameter list.
  1226   /// \relates DigraphReader
  1227   /// \sa digraphReader(TDGR& digraph, const std::string& fn)
  1228   /// \sa digraphReader(TDGR& digraph, const char* fn)
  1229   template <typename TDGR>
  1230   DigraphReader<TDGR> digraphReader(TDGR& digraph, std::istream& is) {
  1231     DigraphReader<TDGR> tmp(digraph, is);
  1232     return tmp;
  1233   }
  1234 
  1235   /// \brief Return a \ref DigraphReader class
  1236   ///
  1237   /// This function just returns a \ref DigraphReader class.
  1238   /// \relates DigraphReader
  1239   /// \sa digraphReader(TDGR& digraph, std::istream& is)
  1240   template <typename TDGR>
  1241   DigraphReader<TDGR> digraphReader(TDGR& digraph, const std::string& fn) {
  1242     DigraphReader<TDGR> tmp(digraph, fn);
  1243     return tmp;
  1244   }
  1245 
  1246   /// \brief Return a \ref DigraphReader class
  1247   ///
  1248   /// This function just returns a \ref DigraphReader class.
  1249   /// \relates DigraphReader
  1250   /// \sa digraphReader(TDGR& digraph, std::istream& is)
  1251   template <typename TDGR>
  1252   DigraphReader<TDGR> digraphReader(TDGR& digraph, const char* fn) {
  1253     DigraphReader<TDGR> tmp(digraph, fn);
  1254     return tmp;
  1255   }
  1256 
  1257   template <typename GR>
  1258   class GraphReader;
  1259 
  1260   template <typename TGR>
  1261   GraphReader<TGR> graphReader(TGR& graph, std::istream& is = std::cin);
  1262   template <typename TGR>
  1263   GraphReader<TGR> graphReader(TGR& graph, const std::string& fn);
  1264   template <typename TGR>
  1265   GraphReader<TGR> graphReader(TGR& graph, const char *fn);
  1266 
  1267   /// \ingroup lemon_io
  1268   ///
  1269   /// \brief \ref lgf-format "LGF" reader for undirected graphs
  1270   ///
  1271   /// This utility reads an \ref lgf-format "LGF" file.
  1272   ///
  1273   /// It can be used almost the same way as \c DigraphReader.
  1274   /// The only difference is that this class can handle edges and
  1275   /// edge maps as well as arcs and arc maps.
  1276   ///
  1277   /// The columns in the \c \@edges (or \c \@arcs) section are the
  1278   /// edge maps. However, if there are two maps with the same name
  1279   /// prefixed with \c '+' and \c '-', then these can be read into an
  1280   /// arc map.  Similarly, an attribute can be read into an arc, if
  1281   /// it's value is an edge label prefixed with \c '+' or \c '-'.
  1282   template <typename GR>
  1283   class GraphReader {
  1284   public:
  1285 
  1286     typedef GR Graph;
  1287 
  1288   private:
  1289 
  1290     TEMPLATE_GRAPH_TYPEDEFS(GR);
  1291 
  1292     std::istream* _is;
  1293     bool local_is;
  1294     std::string _filename;
  1295 
  1296     GR& _graph;
  1297 
  1298     std::string _nodes_caption;
  1299     std::string _edges_caption;
  1300     std::string _attributes_caption;
  1301 
  1302     typedef std::map<std::string, Node> NodeIndex;
  1303     NodeIndex _node_index;
  1304     typedef std::map<std::string, Edge> EdgeIndex;
  1305     EdgeIndex _edge_index;
  1306 
  1307     typedef std::vector<std::pair<std::string,
  1308       _reader_bits::MapStorageBase<Node>*> > NodeMaps;
  1309     NodeMaps _node_maps;
  1310 
  1311     typedef std::vector<std::pair<std::string,
  1312       _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
  1313     EdgeMaps _edge_maps;
  1314 
  1315     typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
  1316       Attributes;
  1317     Attributes _attributes;
  1318 
  1319     bool _use_nodes;
  1320     bool _use_edges;
  1321 
  1322     bool _skip_nodes;
  1323     bool _skip_edges;
  1324 
  1325     int line_num;
  1326     std::istringstream line;
  1327 
  1328   public:
  1329 
  1330     /// \brief Constructor
  1331     ///
  1332     /// Construct an undirected graph reader, which reads from the given
  1333     /// input stream.
  1334     GraphReader(GR& graph, std::istream& is = std::cin)
  1335       : _is(&is), local_is(false), _graph(graph),
  1336         _use_nodes(false), _use_edges(false),
  1337         _skip_nodes(false), _skip_edges(false) {}
  1338 
  1339     /// \brief Constructor
  1340     ///
  1341     /// Construct an undirected graph reader, which reads from the given
  1342     /// file.
  1343     GraphReader(GR& graph, const std::string& fn)
  1344       : _is(new std::ifstream(fn.c_str())), local_is(true),
  1345         _filename(fn), _graph(graph),
  1346         _use_nodes(false), _use_edges(false),
  1347         _skip_nodes(false), _skip_edges(false) {
  1348       if (!(*_is)) {
  1349         delete _is;
  1350         throw IoError("Cannot open file", fn);
  1351       }
  1352     }
  1353 
  1354     /// \brief Constructor
  1355     ///
  1356     /// Construct an undirected graph reader, which reads from the given
  1357     /// file.
  1358     GraphReader(GR& graph, const char* fn)
  1359       : _is(new std::ifstream(fn)), local_is(true),
  1360         _filename(fn), _graph(graph),
  1361         _use_nodes(false), _use_edges(false),
  1362         _skip_nodes(false), _skip_edges(false) {
  1363       if (!(*_is)) {
  1364         delete _is;
  1365         throw IoError("Cannot open file", fn);
  1366       }
  1367     }
  1368 
  1369     /// \brief Destructor
  1370     ~GraphReader() {
  1371       for (typename NodeMaps::iterator it = _node_maps.begin();
  1372            it != _node_maps.end(); ++it) {
  1373         delete it->second;
  1374       }
  1375 
  1376       for (typename EdgeMaps::iterator it = _edge_maps.begin();
  1377            it != _edge_maps.end(); ++it) {
  1378         delete it->second;
  1379       }
  1380 
  1381       for (typename Attributes::iterator it = _attributes.begin();
  1382            it != _attributes.end(); ++it) {
  1383         delete it->second;
  1384       }
  1385 
  1386       if (local_is) {
  1387         delete _is;
  1388       }
  1389 
  1390     }
  1391 
  1392   private:
  1393     template <typename TGR>
  1394     friend GraphReader<TGR> graphReader(TGR& graph, std::istream& is);
  1395     template <typename TGR>
  1396     friend GraphReader<TGR> graphReader(TGR& graph, const std::string& fn);
  1397     template <typename TGR>
  1398     friend GraphReader<TGR> graphReader(TGR& graph, const char *fn);
  1399 
  1400     GraphReader(GraphReader& other)
  1401       : _is(other._is), local_is(other.local_is), _graph(other._graph),
  1402         _use_nodes(other._use_nodes), _use_edges(other._use_edges),
  1403         _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
  1404 
  1405       other._is = 0;
  1406       other.local_is = false;
  1407 
  1408       _node_index.swap(other._node_index);
  1409       _edge_index.swap(other._edge_index);
  1410 
  1411       _node_maps.swap(other._node_maps);
  1412       _edge_maps.swap(other._edge_maps);
  1413       _attributes.swap(other._attributes);
  1414 
  1415       _nodes_caption = other._nodes_caption;
  1416       _edges_caption = other._edges_caption;
  1417       _attributes_caption = other._attributes_caption;
  1418 
  1419     }
  1420 
  1421     GraphReader& operator=(const GraphReader&);
  1422 
  1423   public:
  1424 
  1425     /// \name Reading Rules
  1426     /// @{
  1427 
  1428     /// \brief Node map reading rule
  1429     ///
  1430     /// Add a node map reading rule to the reader.
  1431     template <typename Map>
  1432     GraphReader& nodeMap(const std::string& caption, Map& map) {
  1433       checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
  1434       _reader_bits::MapStorageBase<Node>* storage =
  1435         new _reader_bits::MapStorage<Node, Map>(map);
  1436       _node_maps.push_back(std::make_pair(caption, storage));
  1437       return *this;
  1438     }
  1439 
  1440     /// \brief Node map reading rule
  1441     ///
  1442     /// Add a node map reading rule with specialized converter to the
  1443     /// reader.
  1444     template <typename Map, typename Converter>
  1445     GraphReader& nodeMap(const std::string& caption, Map& map,
  1446                            const Converter& converter = Converter()) {
  1447       checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
  1448       _reader_bits::MapStorageBase<Node>* storage =
  1449         new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
  1450       _node_maps.push_back(std::make_pair(caption, storage));
  1451       return *this;
  1452     }
  1453 
  1454     /// \brief Edge map reading rule
  1455     ///
  1456     /// Add an edge map reading rule to the reader.
  1457     template <typename Map>
  1458     GraphReader& edgeMap(const std::string& caption, Map& map) {
  1459       checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
  1460       _reader_bits::MapStorageBase<Edge>* storage =
  1461         new _reader_bits::MapStorage<Edge, Map>(map);
  1462       _edge_maps.push_back(std::make_pair(caption, storage));
  1463       return *this;
  1464     }
  1465 
  1466     /// \brief Edge map reading rule
  1467     ///
  1468     /// Add an edge map reading rule with specialized converter to the
  1469     /// reader.
  1470     template <typename Map, typename Converter>
  1471     GraphReader& edgeMap(const std::string& caption, Map& map,
  1472                           const Converter& converter = Converter()) {
  1473       checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
  1474       _reader_bits::MapStorageBase<Edge>* storage =
  1475         new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
  1476       _edge_maps.push_back(std::make_pair(caption, storage));
  1477       return *this;
  1478     }
  1479 
  1480     /// \brief Arc map reading rule
  1481     ///
  1482     /// Add an arc map reading rule to the reader.
  1483     template <typename Map>
  1484     GraphReader& arcMap(const std::string& caption, Map& map) {
  1485       checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
  1486       _reader_bits::MapStorageBase<Edge>* forward_storage =
  1487         new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
  1488       _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
  1489       _reader_bits::MapStorageBase<Edge>* backward_storage =
  1490         new _reader_bits::GraphArcMapStorage<GR, false, Map>(_graph, map);
  1491       _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
  1492       return *this;
  1493     }
  1494 
  1495     /// \brief Arc map reading rule
  1496     ///
  1497     /// Add an arc map reading rule with specialized converter to the
  1498     /// reader.
  1499     template <typename Map, typename Converter>
  1500     GraphReader& arcMap(const std::string& caption, Map& map,
  1501                           const Converter& converter = Converter()) {
  1502       checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
  1503       _reader_bits::MapStorageBase<Edge>* forward_storage =
  1504         new _reader_bits::GraphArcMapStorage<GR, true, Map, Converter>
  1505         (_graph, map, converter);
  1506       _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
  1507       _reader_bits::MapStorageBase<Edge>* backward_storage =
  1508         new _reader_bits::GraphArcMapStorage<GR, false, Map, Converter>
  1509         (_graph, map, converter);
  1510       _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
  1511       return *this;
  1512     }
  1513 
  1514     /// \brief Attribute reading rule
  1515     ///
  1516     /// Add an attribute reading rule to the reader.
  1517     template <typename Value>
  1518     GraphReader& attribute(const std::string& caption, Value& value) {
  1519       _reader_bits::ValueStorageBase* storage =
  1520         new _reader_bits::ValueStorage<Value>(value);
  1521       _attributes.insert(std::make_pair(caption, storage));
  1522       return *this;
  1523     }
  1524 
  1525     /// \brief Attribute reading rule
  1526     ///
  1527     /// Add an attribute reading rule with specialized converter to the
  1528     /// reader.
  1529     template <typename Value, typename Converter>
  1530     GraphReader& attribute(const std::string& caption, Value& value,
  1531                              const Converter& converter = Converter()) {
  1532       _reader_bits::ValueStorageBase* storage =
  1533         new _reader_bits::ValueStorage<Value, Converter>(value, converter);
  1534       _attributes.insert(std::make_pair(caption, storage));
  1535       return *this;
  1536     }
  1537 
  1538     /// \brief Node reading rule
  1539     ///
  1540     /// Add a node reading rule to reader.
  1541     GraphReader& node(const std::string& caption, Node& node) {
  1542       typedef _reader_bits::MapLookUpConverter<Node> Converter;
  1543       Converter converter(_node_index);
  1544       _reader_bits::ValueStorageBase* storage =
  1545         new _reader_bits::ValueStorage<Node, Converter>(node, converter);
  1546       _attributes.insert(std::make_pair(caption, storage));
  1547       return *this;
  1548     }
  1549 
  1550     /// \brief Edge reading rule
  1551     ///
  1552     /// Add an edge reading rule to reader.
  1553     GraphReader& edge(const std::string& caption, Edge& edge) {
  1554       typedef _reader_bits::MapLookUpConverter<Edge> Converter;
  1555       Converter converter(_edge_index);
  1556       _reader_bits::ValueStorageBase* storage =
  1557         new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
  1558       _attributes.insert(std::make_pair(caption, storage));
  1559       return *this;
  1560     }
  1561 
  1562     /// \brief Arc reading rule
  1563     ///
  1564     /// Add an arc reading rule to reader.
  1565     GraphReader& arc(const std::string& caption, Arc& arc) {
  1566       typedef _reader_bits::GraphArcLookUpConverter<GR> Converter;
  1567       Converter converter(_graph, _edge_index);
  1568       _reader_bits::ValueStorageBase* storage =
  1569         new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
  1570       _attributes.insert(std::make_pair(caption, storage));
  1571       return *this;
  1572     }
  1573 
  1574     /// @}
  1575 
  1576     /// \name Select Section by Name
  1577     /// @{
  1578 
  1579     /// \brief Set \c \@nodes section to be read
  1580     ///
  1581     /// Set \c \@nodes section to be read.
  1582     GraphReader& nodes(const std::string& caption) {
  1583       _nodes_caption = caption;
  1584       return *this;
  1585     }
  1586 
  1587     /// \brief Set \c \@edges section to be read
  1588     ///
  1589     /// Set \c \@edges section to be read.
  1590     GraphReader& edges(const std::string& caption) {
  1591       _edges_caption = caption;
  1592       return *this;
  1593     }
  1594 
  1595     /// \brief Set \c \@attributes section to be read
  1596     ///
  1597     /// Set \c \@attributes section to be read.
  1598     GraphReader& attributes(const std::string& caption) {
  1599       _attributes_caption = caption;
  1600       return *this;
  1601     }
  1602 
  1603     /// @}
  1604 
  1605     /// \name Using Previously Constructed Node or Edge Set
  1606     /// @{
  1607 
  1608     /// \brief Use previously constructed node set
  1609     ///
  1610     /// Use previously constructed node set, and specify the node
  1611     /// label map.
  1612     template <typename Map>
  1613     GraphReader& useNodes(const Map& map) {
  1614       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
  1615       LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
  1616       _use_nodes = true;
  1617       _writer_bits::DefaultConverter<typename Map::Value> converter;
  1618       for (NodeIt n(_graph); n != INVALID; ++n) {
  1619         _node_index.insert(std::make_pair(converter(map[n]), n));
  1620       }
  1621       return *this;
  1622     }
  1623 
  1624     /// \brief Use previously constructed node set
  1625     ///
  1626     /// Use previously constructed node set, and specify the node
  1627     /// label map and a functor which converts the label map values to
  1628     /// \c std::string.
  1629     template <typename Map, typename Converter>
  1630     GraphReader& useNodes(const Map& map,
  1631                             const Converter& converter = Converter()) {
  1632       checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
  1633       LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
  1634       _use_nodes = true;
  1635       for (NodeIt n(_graph); n != INVALID; ++n) {
  1636         _node_index.insert(std::make_pair(converter(map[n]), n));
  1637       }
  1638       return *this;
  1639     }
  1640 
  1641     /// \brief Use previously constructed edge set
  1642     ///
  1643     /// Use previously constructed edge set, and specify the edge
  1644     /// label map.
  1645     template <typename Map>
  1646     GraphReader& useEdges(const Map& map) {
  1647       checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
  1648       LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
  1649       _use_edges = true;
  1650       _writer_bits::DefaultConverter<typename Map::Value> converter;
  1651       for (EdgeIt a(_graph); a != INVALID; ++a) {
  1652         _edge_index.insert(std::make_pair(converter(map[a]), a));
  1653       }
  1654       return *this;
  1655     }
  1656 
  1657     /// \brief Use previously constructed edge set
  1658     ///
  1659     /// Use previously constructed edge set, and specify the edge
  1660     /// label map and a functor which converts the label map values to
  1661     /// \c std::string.
  1662     template <typename Map, typename Converter>
  1663     GraphReader& useEdges(const Map& map,
  1664                             const Converter& converter = Converter()) {
  1665       checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
  1666       LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
  1667       _use_edges = true;
  1668       for (EdgeIt a(_graph); a != INVALID; ++a) {
  1669         _edge_index.insert(std::make_pair(converter(map[a]), a));
  1670       }
  1671       return *this;
  1672     }
  1673 
  1674     /// \brief Skip the reading of node section
  1675     ///
  1676     /// Omit the reading of the node section. This implies that each node
  1677     /// map reading rule will be abandoned, and the nodes of the graph
  1678     /// will not be constructed, which usually cause that the edge set
  1679     /// could not be read due to lack of node name
  1680     /// could not be read due to lack of node name resolving.
  1681     /// Therefore \c skipEdges() function should also be used, or
  1682     /// \c useNodes() should be used to specify the label of the nodes.
  1683     GraphReader& skipNodes() {
  1684       LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
  1685       _skip_nodes = true;
  1686       return *this;
  1687     }
  1688 
  1689     /// \brief Skip the reading of edge section
  1690     ///
  1691     /// Omit the reading of the edge section. This implies that each edge
  1692     /// map reading rule will be abandoned, and the edges of the graph
  1693     /// will not be constructed.
  1694     GraphReader& skipEdges() {
  1695       LEMON_ASSERT(!_skip_edges, "Skip edges already set");
  1696       _skip_edges = true;
  1697       return *this;
  1698     }
  1699 
  1700     /// @}
  1701 
  1702   private:
  1703 
  1704     bool readLine() {
  1705       std::string str;
  1706       while(++line_num, std::getline(*_is, str)) {
  1707         line.clear(); line.str(str);
  1708         char c;
  1709         if (line >> std::ws >> c && c != '#') {
  1710           line.putback(c);
  1711           return true;
  1712         }
  1713       }
  1714       return false;
  1715     }
  1716 
  1717     bool readSuccess() {
  1718       return static_cast<bool>(*_is);
  1719     }
  1720 
  1721     void skipSection() {
  1722       char c;
  1723       while (readSuccess() && line >> c && c != '@') {
  1724         readLine();
  1725       }
  1726       if (readSuccess()) {
  1727         line.putback(c);
  1728       }
  1729     }
  1730 
  1731     void readNodes() {
  1732 
  1733       std::vector<int> map_index(_node_maps.size());
  1734       int map_num, label_index;
  1735 
  1736       char c;
  1737       if (!readLine() || !(line >> c) || c == '@') {
  1738         if (readSuccess() && line) line.putback(c);
  1739         if (!_node_maps.empty())
  1740           throw FormatError("Cannot find map names");
  1741         return;
  1742       }
  1743       line.putback(c);
  1744 
  1745       {
  1746         std::map<std::string, int> maps;
  1747 
  1748         std::string map;
  1749         int index = 0;
  1750         while (_reader_bits::readToken(line, map)) {
  1751           if (maps.find(map) != maps.end()) {
  1752             std::ostringstream msg;
  1753             msg << "Multiple occurence of node map: " << map;
  1754             throw FormatError(msg.str());
  1755           }
  1756           maps.insert(std::make_pair(map, index));
  1757           ++index;
  1758         }
  1759 
  1760         for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
  1761           std::map<std::string, int>::iterator jt =
  1762             maps.find(_node_maps[i].first);
  1763           if (jt == maps.end()) {
  1764             std::ostringstream msg;
  1765             msg << "Map not found: " << _node_maps[i].first;
  1766             throw FormatError(msg.str());
  1767           }
  1768           map_index[i] = jt->second;
  1769         }
  1770 
  1771         {
  1772           std::map<std::string, int>::iterator jt = maps.find("label");
  1773           if (jt != maps.end()) {
  1774             label_index = jt->second;
  1775           } else {
  1776             label_index = -1;
  1777           }
  1778         }
  1779         map_num = maps.size();
  1780       }
  1781 
  1782       while (readLine() && line >> c && c != '@') {
  1783         line.putback(c);
  1784 
  1785         std::vector<std::string> tokens(map_num);
  1786         for (int i = 0; i < map_num; ++i) {
  1787           if (!_reader_bits::readToken(line, tokens[i])) {
  1788             std::ostringstream msg;
  1789             msg << "Column not found (" << i + 1 << ")";
  1790             throw FormatError(msg.str());
  1791           }
  1792         }
  1793         if (line >> std::ws >> c)
  1794           throw FormatError("Extra character at the end of line");
  1795 
  1796         Node n;
  1797         if (!_use_nodes) {
  1798           n = _graph.addNode();
  1799           if (label_index != -1)
  1800             _node_index.insert(std::make_pair(tokens[label_index], n));
  1801         } else {
  1802           if (label_index == -1)
  1803             throw FormatError("Label map not found");
  1804           typename std::map<std::string, Node>::iterator it =
  1805             _node_index.find(tokens[label_index]);
  1806           if (it == _node_index.end()) {
  1807             std::ostringstream msg;
  1808             msg << "Node with label not found: " << tokens[label_index];
  1809             throw FormatError(msg.str());
  1810           }
  1811           n = it->second;
  1812         }
  1813 
  1814         for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
  1815           _node_maps[i].second->set(n, tokens[map_index[i]]);
  1816         }
  1817 
  1818       }
  1819       if (readSuccess()) {
  1820         line.putback(c);
  1821       }
  1822     }
  1823 
  1824     void readEdges() {
  1825 
  1826       std::vector<int> map_index(_edge_maps.size());
  1827       int map_num, label_index;
  1828 
  1829       char c;
  1830       if (!readLine() || !(line >> c) || c == '@') {
  1831         if (readSuccess() && line) line.putback(c);
  1832         if (!_edge_maps.empty())
  1833           throw FormatError("Cannot find map names");
  1834         return;
  1835       }
  1836       line.putback(c);
  1837 
  1838       {
  1839         std::map<std::string, int> maps;
  1840 
  1841         std::string map;
  1842         int index = 0;
  1843         while (_reader_bits::readToken(line, map)) {
  1844           if(map == "-") {
  1845               if(index!=0)
  1846                 throw FormatError("'-' is not allowed as a map name");
  1847               else if (line >> std::ws >> c)
  1848                 throw FormatError("Extra character at the end of line");
  1849               else break;
  1850             }
  1851           if (maps.find(map) != maps.end()) {
  1852             std::ostringstream msg;
  1853             msg << "Multiple occurence of edge map: " << map;
  1854             throw FormatError(msg.str());
  1855           }
  1856           maps.insert(std::make_pair(map, index));
  1857           ++index;
  1858         }
  1859 
  1860         for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
  1861           std::map<std::string, int>::iterator jt =
  1862             maps.find(_edge_maps[i].first);
  1863           if (jt == maps.end()) {
  1864             std::ostringstream msg;
  1865             msg << "Map not found: " << _edge_maps[i].first;
  1866             throw FormatError(msg.str());
  1867           }
  1868           map_index[i] = jt->second;
  1869         }
  1870 
  1871         {
  1872           std::map<std::string, int>::iterator jt = maps.find("label");
  1873           if (jt != maps.end()) {
  1874             label_index = jt->second;
  1875           } else {
  1876             label_index = -1;
  1877           }
  1878         }
  1879         map_num = maps.size();
  1880       }
  1881 
  1882       while (readLine() && line >> c && c != '@') {
  1883         line.putback(c);
  1884 
  1885         std::string source_token;
  1886         std::string target_token;
  1887 
  1888         if (!_reader_bits::readToken(line, source_token))
  1889           throw FormatError("Node u not found");
  1890 
  1891         if (!_reader_bits::readToken(line, target_token))
  1892           throw FormatError("Node v not found");
  1893 
  1894         std::vector<std::string> tokens(map_num);
  1895         for (int i = 0; i < map_num; ++i) {
  1896           if (!_reader_bits::readToken(line, tokens[i])) {
  1897             std::ostringstream msg;
  1898             msg << "Column not found (" << i + 1 << ")";
  1899             throw FormatError(msg.str());
  1900           }
  1901         }
  1902         if (line >> std::ws >> c)
  1903           throw FormatError("Extra character at the end of line");
  1904 
  1905         Edge e;
  1906         if (!_use_edges) {
  1907 
  1908           typename NodeIndex::iterator it;
  1909 
  1910           it = _node_index.find(source_token);
  1911           if (it == _node_index.end()) {
  1912             std::ostringstream msg;
  1913             msg << "Item not found: " << source_token;
  1914             throw FormatError(msg.str());
  1915           }
  1916           Node source = it->second;
  1917 
  1918           it = _node_index.find(target_token);
  1919           if (it == _node_index.end()) {
  1920             std::ostringstream msg;
  1921             msg << "Item not found: " << target_token;
  1922             throw FormatError(msg.str());
  1923           }
  1924           Node target = it->second;
  1925 
  1926           e = _graph.addEdge(source, target);
  1927           if (label_index != -1)
  1928             _edge_index.insert(std::make_pair(tokens[label_index], e));
  1929         } else {
  1930           if (label_index == -1)
  1931             throw FormatError("Label map not found");
  1932           typename std::map<std::string, Edge>::iterator it =
  1933             _edge_index.find(tokens[label_index]);
  1934           if (it == _edge_index.end()) {
  1935             std::ostringstream msg;
  1936             msg << "Edge with label not found: " << tokens[label_index];
  1937             throw FormatError(msg.str());
  1938           }
  1939           e = it->second;
  1940         }
  1941 
  1942         for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
  1943           _edge_maps[i].second->set(e, tokens[map_index[i]]);
  1944         }
  1945 
  1946       }
  1947       if (readSuccess()) {
  1948         line.putback(c);
  1949       }
  1950     }
  1951 
  1952     void readAttributes() {
  1953 
  1954       std::set<std::string> read_attr;
  1955 
  1956       char c;
  1957       while (readLine() && line >> c && c != '@') {
  1958         line.putback(c);
  1959 
  1960         std::string attr, token;
  1961         if (!_reader_bits::readToken(line, attr))
  1962           throw FormatError("Attribute name not found");
  1963         if (!_reader_bits::readToken(line, token))
  1964           throw FormatError("Attribute value not found");
  1965         if (line >> c)
  1966           throw FormatError("Extra character at the end of line");
  1967 
  1968         {
  1969           std::set<std::string>::iterator it = read_attr.find(attr);
  1970           if (it != read_attr.end()) {
  1971             std::ostringstream msg;
  1972             msg << "Multiple occurence of attribute: " << attr;
  1973             throw FormatError(msg.str());
  1974           }
  1975           read_attr.insert(attr);
  1976         }
  1977 
  1978         {
  1979           typename Attributes::iterator it = _attributes.lower_bound(attr);
  1980           while (it != _attributes.end() && it->first == attr) {
  1981             it->second->set(token);
  1982             ++it;
  1983           }
  1984         }
  1985 
  1986       }
  1987       if (readSuccess()) {
  1988         line.putback(c);
  1989       }
  1990       for (typename Attributes::iterator it = _attributes.begin();
  1991            it != _attributes.end(); ++it) {
  1992         if (read_attr.find(it->first) == read_attr.end()) {
  1993           std::ostringstream msg;
  1994           msg << "Attribute not found: " << it->first;
  1995           throw FormatError(msg.str());
  1996         }
  1997       }
  1998     }
  1999 
  2000   public:
  2001 
  2002     /// \name Execution of the Reader
  2003     /// @{
  2004 
  2005     /// \brief Start the batch processing
  2006     ///
  2007     /// This function starts the batch processing
  2008     void run() {
  2009 
  2010       LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
  2011 
  2012       bool nodes_done = _skip_nodes;
  2013       bool edges_done = _skip_edges;
  2014       bool attributes_done = false;
  2015 
  2016       line_num = 0;
  2017       readLine();
  2018       skipSection();
  2019 
  2020       while (readSuccess()) {
  2021         try {
  2022           char c;
  2023           std::string section, caption;
  2024           line >> c;
  2025           _reader_bits::readToken(line, section);
  2026           _reader_bits::readToken(line, caption);
  2027 
  2028           if (line >> c)
  2029             throw FormatError("Extra character at the end of line");
  2030 
  2031           if (section == "nodes" && !nodes_done) {
  2032             if (_nodes_caption.empty() || _nodes_caption == caption) {
  2033               readNodes();
  2034               nodes_done = true;
  2035             }
  2036           } else if ((section == "edges" || section == "arcs") &&
  2037                      !edges_done) {
  2038             if (_edges_caption.empty() || _edges_caption == caption) {
  2039               readEdges();
  2040               edges_done = true;
  2041             }
  2042           } else if (section == "attributes" && !attributes_done) {
  2043             if (_attributes_caption.empty() || _attributes_caption == caption) {
  2044               readAttributes();
  2045               attributes_done = true;
  2046             }
  2047           } else {
  2048             readLine();
  2049             skipSection();
  2050           }
  2051         } catch (FormatError& error) {
  2052           error.line(line_num);
  2053           error.file(_filename);
  2054           throw;
  2055         }
  2056       }
  2057 
  2058       if (!nodes_done) {
  2059         throw FormatError("Section @nodes not found");
  2060       }
  2061 
  2062       if (!edges_done) {
  2063         throw FormatError("Section @edges not found");
  2064       }
  2065 
  2066       if (!attributes_done && !_attributes.empty()) {
  2067         throw FormatError("Section @attributes not found");
  2068       }
  2069 
  2070     }
  2071 
  2072     /// @}
  2073 
  2074   };
  2075 
  2076   /// \ingroup lemon_io
  2077   ///
  2078   /// \brief Return a \ref GraphReader class
  2079   ///
  2080   /// This function just returns a \ref GraphReader class.
  2081   ///
  2082   /// With this function a graph can be read from an
  2083   /// \ref lgf-format "LGF" file or input stream with several maps and
  2084   /// attributes. For example, there is weighted matching problem on a
  2085   /// graph, i.e. a graph with a \e weight map on the edges. This
  2086   /// graph can be read with the following code:
  2087   ///
  2088   ///\code
  2089   ///ListGraph graph;
  2090   ///ListGraph::EdgeMap<int> weight(graph);
  2091   ///graphReader(graph, std::cin).
  2092   ///  edgeMap("weight", weight).
  2093   ///  run();
  2094   ///\endcode
  2095   ///
  2096   /// For a complete documentation, please see the \ref GraphReader
  2097   /// class documentation.
  2098   /// \warning Don't forget to put the \ref GraphReader::run() "run()"
  2099   /// to the end of the parameter list.
  2100   /// \relates GraphReader
  2101   /// \sa graphReader(TGR& graph, const std::string& fn)
  2102   /// \sa graphReader(TGR& graph, const char* fn)
  2103   template <typename TGR>
  2104   GraphReader<TGR> graphReader(TGR& graph, std::istream& is) {
  2105     GraphReader<TGR> tmp(graph, is);
  2106     return tmp;
  2107   }
  2108 
  2109   /// \brief Return a \ref GraphReader class
  2110   ///
  2111   /// This function just returns a \ref GraphReader class.
  2112   /// \relates GraphReader
  2113   /// \sa graphReader(TGR& graph, std::istream& is)
  2114   template <typename TGR>
  2115   GraphReader<TGR> graphReader(TGR& graph, const std::string& fn) {
  2116     GraphReader<TGR> tmp(graph, fn);
  2117     return tmp;
  2118   }
  2119 
  2120   /// \brief Return a \ref GraphReader class
  2121   ///
  2122   /// This function just returns a \ref GraphReader class.
  2123   /// \relates GraphReader
  2124   /// \sa graphReader(TGR& graph, std::istream& is)
  2125   template <typename TGR>
  2126   GraphReader<TGR> graphReader(TGR& graph, const char* fn) {
  2127     GraphReader<TGR> tmp(graph, fn);
  2128     return tmp;
  2129   }
  2130 
  2131   class SectionReader;
  2132 
  2133   SectionReader sectionReader(std::istream& is);
  2134   SectionReader sectionReader(const std::string& fn);
  2135   SectionReader sectionReader(const char* fn);
  2136 
  2137   /// \ingroup lemon_io
  2138   ///
  2139   /// \brief Section reader class
  2140   ///
  2141   /// In the \ref lgf-format "LGF" file extra sections can be placed,
  2142   /// which contain any data in arbitrary format. Such sections can be
  2143   /// read with this class. A reading rule can be added to the class
  2144   /// with two different functions. With the \c sectionLines() function a
  2145   /// functor can process the section line-by-line, while with the \c
  2146   /// sectionStream() member the section can be read from an input
  2147   /// stream.
  2148   class SectionReader {
  2149   private:
  2150 
  2151     std::istream* _is;
  2152     bool local_is;
  2153     std::string _filename;
  2154 
  2155     typedef std::map<std::string, _reader_bits::Section*> Sections;
  2156     Sections _sections;
  2157 
  2158     int line_num;
  2159     std::istringstream line;
  2160 
  2161   public:
  2162 
  2163     /// \brief Constructor
  2164     ///
  2165     /// Construct a section reader, which reads from the given input
  2166     /// stream.
  2167     SectionReader(std::istream& is)
  2168       : _is(&is), local_is(false) {}
  2169 
  2170     /// \brief Constructor
  2171     ///
  2172     /// Construct a section reader, which reads from the given file.
  2173     SectionReader(const std::string& fn)
  2174       : _is(new std::ifstream(fn.c_str())), local_is(true),
  2175         _filename(fn) {
  2176       if (!(*_is)) {
  2177         delete _is;
  2178         throw IoError("Cannot open file", fn);
  2179       }
  2180     }
  2181 
  2182     /// \brief Constructor
  2183     ///
  2184     /// Construct a section reader, which reads from the given file.
  2185     SectionReader(const char* fn)
  2186       : _is(new std::ifstream(fn)), local_is(true),
  2187         _filename(fn) {
  2188       if (!(*_is)) {
  2189         delete _is;
  2190         throw IoError("Cannot open file", fn);
  2191       }
  2192     }
  2193 
  2194     /// \brief Destructor
  2195     ~SectionReader() {
  2196       for (Sections::iterator it = _sections.begin();
  2197            it != _sections.end(); ++it) {
  2198         delete it->second;
  2199       }
  2200 
  2201       if (local_is) {
  2202         delete _is;
  2203       }
  2204 
  2205     }
  2206 
  2207   private:
  2208 
  2209     friend SectionReader sectionReader(std::istream& is);
  2210     friend SectionReader sectionReader(const std::string& fn);
  2211     friend SectionReader sectionReader(const char* fn);
  2212 
  2213     SectionReader(SectionReader& other)
  2214       : _is(other._is), local_is(other.local_is) {
  2215 
  2216       other._is = 0;
  2217       other.local_is = false;
  2218 
  2219       _sections.swap(other._sections);
  2220     }
  2221 
  2222     SectionReader& operator=(const SectionReader&);
  2223 
  2224   public:
  2225 
  2226     /// \name Section Readers
  2227     /// @{
  2228 
  2229     /// \brief Add a section processor with line oriented reading
  2230     ///
  2231     /// The first parameter is the type descriptor of the section, the
  2232     /// second is a functor, which takes just one \c std::string
  2233     /// parameter. At the reading process, each line of the section
  2234     /// will be given to the functor object. However, the empty lines
  2235     /// and the comment lines are filtered out, and the leading
  2236     /// whitespaces are trimmed from each processed string.
  2237     ///
  2238     /// For example, let's see a section, which contain several
  2239     /// integers, which should be inserted into a vector.
  2240     ///\code
  2241     ///  @numbers
  2242     ///  12 45 23
  2243     ///  4
  2244     ///  23 6
  2245     ///\endcode
  2246     ///
  2247     /// The functor is implemented as a struct:
  2248     ///\code
  2249     ///  struct NumberSection {
  2250     ///    std::vector<int>& _data;
  2251     ///    NumberSection(std::vector<int>& data) : _data(data) {}
  2252     ///    void operator()(const std::string& line) {
  2253     ///      std::istringstream ls(line);
  2254     ///      int value;
  2255     ///      while (ls >> value) _data.push_back(value);
  2256     ///    }
  2257     ///  };
  2258     ///
  2259     ///  // ...
  2260     ///
  2261     ///  reader.sectionLines("numbers", NumberSection(vec));
  2262     ///\endcode
  2263     template <typename Functor>
  2264     SectionReader& sectionLines(const std::string& type, Functor functor) {
  2265       LEMON_ASSERT(!type.empty(), "Type is empty.");
  2266       LEMON_ASSERT(_sections.find(type) == _sections.end(),
  2267                    "Multiple reading of section.");
  2268       _sections.insert(std::make_pair(type,
  2269         new _reader_bits::LineSection<Functor>(functor)));
  2270       return *this;
  2271     }
  2272 
  2273 
  2274     /// \brief Add a section processor with stream oriented reading
  2275     ///
  2276     /// The first parameter is the type of the section, the second is
  2277     /// a functor, which takes an \c std::istream& and an \c int&
  2278     /// parameter, the latter regard to the line number of stream. The
  2279     /// functor can read the input while the section go on, and the
  2280     /// line number should be modified accordingly.
  2281     template <typename Functor>
  2282     SectionReader& sectionStream(const std::string& type, Functor functor) {
  2283       LEMON_ASSERT(!type.empty(), "Type is empty.");
  2284       LEMON_ASSERT(_sections.find(type) == _sections.end(),
  2285                    "Multiple reading of section.");
  2286       _sections.insert(std::make_pair(type,
  2287          new _reader_bits::StreamSection<Functor>(functor)));
  2288       return *this;
  2289     }
  2290 
  2291     /// @}
  2292 
  2293   private:
  2294 
  2295     bool readLine() {
  2296       std::string str;
  2297       while(++line_num, std::getline(*_is, str)) {
  2298         line.clear(); line.str(str);
  2299         char c;
  2300         if (line >> std::ws >> c && c != '#') {
  2301           line.putback(c);
  2302           return true;
  2303         }
  2304       }
  2305       return false;
  2306     }
  2307 
  2308     bool readSuccess() {
  2309       return static_cast<bool>(*_is);
  2310     }
  2311 
  2312     void skipSection() {
  2313       char c;
  2314       while (readSuccess() && line >> c && c != '@') {
  2315         readLine();
  2316       }
  2317       if (readSuccess()) {
  2318         line.putback(c);
  2319       }
  2320     }
  2321 
  2322   public:
  2323 
  2324 
  2325     /// \name Execution of the Reader
  2326     /// @{
  2327 
  2328     /// \brief Start the batch processing
  2329     ///
  2330     /// This function starts the batch processing.
  2331     void run() {
  2332 
  2333       LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
  2334 
  2335       std::set<std::string> extra_sections;
  2336 
  2337       line_num = 0;
  2338       readLine();
  2339       skipSection();
  2340 
  2341       while (readSuccess()) {
  2342         try {
  2343           char c;
  2344           std::string section, caption;
  2345           line >> c;
  2346           _reader_bits::readToken(line, section);
  2347           _reader_bits::readToken(line, caption);
  2348 
  2349           if (line >> c)
  2350             throw FormatError("Extra character at the end of line");
  2351 
  2352           if (extra_sections.find(section) != extra_sections.end()) {
  2353             std::ostringstream msg;
  2354             msg << "Multiple occurence of section: " << section;
  2355             throw FormatError(msg.str());
  2356           }
  2357           Sections::iterator it = _sections.find(section);
  2358           if (it != _sections.end()) {
  2359             extra_sections.insert(section);
  2360             it->second->process(*_is, line_num);
  2361           }
  2362           readLine();
  2363           skipSection();
  2364         } catch (FormatError& error) {
  2365           error.line(line_num);
  2366           error.file(_filename);
  2367           throw;
  2368         }
  2369       }
  2370       for (Sections::iterator it = _sections.begin();
  2371            it != _sections.end(); ++it) {
  2372         if (extra_sections.find(it->first) == extra_sections.end()) {
  2373           std::ostringstream os;
  2374           os << "Cannot find section: " << it->first;
  2375           throw FormatError(os.str());
  2376         }
  2377       }
  2378     }
  2379 
  2380     /// @}
  2381 
  2382   };
  2383 
  2384   /// \ingroup lemon_io
  2385   ///
  2386   /// \brief Return a \ref SectionReader class
  2387   ///
  2388   /// This function just returns a \ref SectionReader class.
  2389   ///
  2390   /// Please see SectionReader documentation about the custom section
  2391   /// input.
  2392   ///
  2393   /// \relates SectionReader
  2394   /// \sa sectionReader(const std::string& fn)
  2395   /// \sa sectionReader(const char *fn)
  2396   inline SectionReader sectionReader(std::istream& is) {
  2397     SectionReader tmp(is);
  2398     return tmp;
  2399   }
  2400 
  2401   /// \brief Return a \ref SectionReader class
  2402   ///
  2403   /// This function just returns a \ref SectionReader class.
  2404   /// \relates SectionReader
  2405   /// \sa sectionReader(std::istream& is)
  2406   inline SectionReader sectionReader(const std::string& fn) {
  2407     SectionReader tmp(fn);
  2408     return tmp;
  2409   }
  2410 
  2411   /// \brief Return a \ref SectionReader class
  2412   ///
  2413   /// This function just returns a \ref SectionReader class.
  2414   /// \relates SectionReader
  2415   /// \sa sectionReader(std::istream& is)
  2416   inline SectionReader sectionReader(const char* fn) {
  2417     SectionReader tmp(fn);
  2418     return tmp;
  2419   }
  2420 
  2421   /// \ingroup lemon_io
  2422   ///
  2423   /// \brief Reader for the contents of the \ref lgf-format "LGF" file
  2424   ///
  2425   /// This class can be used to read the sections, the map names and
  2426   /// the attributes from a file. Usually, the LEMON programs know
  2427   /// that, which type of graph, which maps and which attributes
  2428   /// should be read from a file, but in general tools (like glemon)
  2429   /// the contents of an LGF file should be guessed somehow. This class
  2430   /// reads the graph and stores the appropriate information for
  2431   /// reading the graph.
  2432   ///
  2433   ///\code
  2434   /// LgfContents contents("graph.lgf");
  2435   /// contents.run();
  2436   ///
  2437   /// // Does it contain any node section and arc section?
  2438   /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
  2439   ///   std::cerr << "Failure, cannot find graph." << std::endl;
  2440   ///   return -1;
  2441   /// }
  2442   /// std::cout << "The name of the default node section: "
  2443   ///           << contents.nodeSection(0) << std::endl;
  2444   /// std::cout << "The number of the arc maps: "
  2445   ///           << contents.arcMaps(0).size() << std::endl;
  2446   /// std::cout << "The name of second arc map: "
  2447   ///           << contents.arcMaps(0)[1] << std::endl;
  2448   ///\endcode
  2449   class LgfContents {
  2450   private:
  2451 
  2452     std::istream* _is;
  2453     bool local_is;
  2454 
  2455     std::vector<std::string> _node_sections;
  2456     std::vector<std::string> _edge_sections;
  2457     std::vector<std::string> _attribute_sections;
  2458     std::vector<std::string> _extra_sections;
  2459 
  2460     std::vector<bool> _arc_sections;
  2461 
  2462     std::vector<std::vector<std::string> > _node_maps;
  2463     std::vector<std::vector<std::string> > _edge_maps;
  2464 
  2465     std::vector<std::vector<std::string> > _attributes;
  2466 
  2467 
  2468     int line_num;
  2469     std::istringstream line;
  2470 
  2471   public:
  2472 
  2473     /// \brief Constructor
  2474     ///
  2475     /// Construct an \e LGF contents reader, which reads from the given
  2476     /// input stream.
  2477     LgfContents(std::istream& is)
  2478       : _is(&is), local_is(false) {}
  2479 
  2480     /// \brief Constructor
  2481     ///
  2482     /// Construct an \e LGF contents reader, which reads from the given
  2483     /// file.
  2484     LgfContents(const std::string& fn)
  2485       : _is(new std::ifstream(fn.c_str())), local_is(true) {
  2486       if (!(*_is)) {
  2487         delete _is;
  2488         throw IoError("Cannot open file", fn);
  2489       }
  2490     }
  2491 
  2492     /// \brief Constructor
  2493     ///
  2494     /// Construct an \e LGF contents reader, which reads from the given
  2495     /// file.
  2496     LgfContents(const char* fn)
  2497       : _is(new std::ifstream(fn)), local_is(true) {
  2498       if (!(*_is)) {
  2499         delete _is;
  2500         throw IoError("Cannot open file", fn);
  2501       }
  2502     }
  2503 
  2504     /// \brief Destructor
  2505     ~LgfContents() {
  2506       if (local_is) delete _is;
  2507     }
  2508 
  2509   private:
  2510 
  2511     LgfContents(const LgfContents&);
  2512     LgfContents& operator=(const LgfContents&);
  2513 
  2514   public:
  2515 
  2516 
  2517     /// \name Node Sections
  2518     /// @{
  2519 
  2520     /// \brief Gives back the number of node sections in the file.
  2521     ///
  2522     /// Gives back the number of node sections in the file.
  2523     int nodeSectionNum() const {
  2524       return _node_sections.size();
  2525     }
  2526 
  2527     /// \brief Returns the node section name at the given position.
  2528     ///
  2529     /// Returns the node section name at the given position.
  2530     const std::string& nodeSection(int i) const {
  2531       return _node_sections[i];
  2532     }
  2533 
  2534     /// \brief Gives back the node maps for the given section.
  2535     ///
  2536     /// Gives back the node maps for the given section.
  2537     const std::vector<std::string>& nodeMapNames(int i) const {
  2538       return _node_maps[i];
  2539     }
  2540 
  2541     /// @}
  2542 
  2543     /// \name Arc/Edge Sections
  2544     /// @{
  2545 
  2546     /// \brief Gives back the number of arc/edge sections in the file.
  2547     ///
  2548     /// Gives back the number of arc/edge sections in the file.
  2549     /// \note It is synonym of \c edgeSectionNum().
  2550     int arcSectionNum() const {
  2551       return _edge_sections.size();
  2552     }
  2553 
  2554     /// \brief Returns the arc/edge section name at the given position.
  2555     ///
  2556     /// Returns the arc/edge section name at the given position.
  2557     /// \note It is synonym of \c edgeSection().
  2558     const std::string& arcSection(int i) const {
  2559       return _edge_sections[i];
  2560     }
  2561 
  2562     /// \brief Gives back the arc/edge maps for the given section.
  2563     ///
  2564     /// Gives back the arc/edge maps for the given section.
  2565     /// \note It is synonym of \c edgeMapNames().
  2566     const std::vector<std::string>& arcMapNames(int i) const {
  2567       return _edge_maps[i];
  2568     }
  2569 
  2570     /// @}
  2571 
  2572     /// \name Synonyms
  2573     /// @{
  2574 
  2575     /// \brief Gives back the number of arc/edge sections in the file.
  2576     ///
  2577     /// Gives back the number of arc/edge sections in the file.
  2578     /// \note It is synonym of \c arcSectionNum().
  2579     int edgeSectionNum() const {
  2580       return _edge_sections.size();
  2581     }
  2582 
  2583     /// \brief Returns the section name at the given position.
  2584     ///
  2585     /// Returns the section name at the given position.
  2586     /// \note It is synonym of \c arcSection().
  2587     const std::string& edgeSection(int i) const {
  2588       return _edge_sections[i];
  2589     }
  2590 
  2591     /// \brief Gives back the edge maps for the given section.
  2592     ///
  2593     /// Gives back the edge maps for the given section.
  2594     /// \note It is synonym of \c arcMapNames().
  2595     const std::vector<std::string>& edgeMapNames(int i) const {
  2596       return _edge_maps[i];
  2597     }
  2598 
  2599     /// @}
  2600 
  2601     /// \name Attribute Sections
  2602     /// @{
  2603 
  2604     /// \brief Gives back the number of attribute sections in the file.
  2605     ///
  2606     /// Gives back the number of attribute sections in the file.
  2607     int attributeSectionNum() const {
  2608       return _attribute_sections.size();
  2609     }
  2610 
  2611     /// \brief Returns the attribute section name at the given position.
  2612     ///
  2613     /// Returns the attribute section name at the given position.
  2614     const std::string& attributeSectionNames(int i) const {
  2615       return _attribute_sections[i];
  2616     }
  2617 
  2618     /// \brief Gives back the attributes for the given section.
  2619     ///
  2620     /// Gives back the attributes for the given section.
  2621     const std::vector<std::string>& attributes(int i) const {
  2622       return _attributes[i];
  2623     }
  2624 
  2625     /// @}
  2626 
  2627     /// \name Extra Sections
  2628     /// @{
  2629 
  2630     /// \brief Gives back the number of extra sections in the file.
  2631     ///
  2632     /// Gives back the number of extra sections in the file.
  2633     int extraSectionNum() const {
  2634       return _extra_sections.size();
  2635     }
  2636 
  2637     /// \brief Returns the extra section type at the given position.
  2638     ///
  2639     /// Returns the section type at the given position.
  2640     const std::string& extraSection(int i) const {
  2641       return _extra_sections[i];
  2642     }
  2643 
  2644     /// @}
  2645 
  2646   private:
  2647 
  2648     bool readLine() {
  2649       std::string str;
  2650       while(++line_num, std::getline(*_is, str)) {
  2651         line.clear(); line.str(str);
  2652         char c;
  2653         if (line >> std::ws >> c && c != '#') {
  2654           line.putback(c);
  2655           return true;
  2656         }
  2657       }
  2658       return false;
  2659     }
  2660 
  2661     bool readSuccess() {
  2662       return static_cast<bool>(*_is);
  2663     }
  2664 
  2665     void skipSection() {
  2666       char c;
  2667       while (readSuccess() && line >> c && c != '@') {
  2668         readLine();
  2669       }
  2670       if (readSuccess()) {
  2671         line.putback(c);
  2672       }
  2673     }
  2674 
  2675     void readMaps(std::vector<std::string>& maps) {
  2676       char c;
  2677       if (!readLine() || !(line >> c) || c == '@') {
  2678         if (readSuccess() && line) line.putback(c);
  2679         return;
  2680       }
  2681       line.putback(c);
  2682       std::string map;
  2683       while (_reader_bits::readToken(line, map)) {
  2684         maps.push_back(map);
  2685       }
  2686     }
  2687 
  2688     void readAttributes(std::vector<std::string>& attrs) {
  2689       readLine();
  2690       char c;
  2691       while (readSuccess() && line >> c && c != '@') {
  2692         line.putback(c);
  2693         std::string attr;
  2694         _reader_bits::readToken(line, attr);
  2695         attrs.push_back(attr);
  2696         readLine();
  2697       }
  2698       line.putback(c);
  2699     }
  2700 
  2701   public:
  2702 
  2703     /// \name Execution of the Contents Reader
  2704     /// @{
  2705 
  2706     /// \brief Starts the reading
  2707     ///
  2708     /// This function starts the reading.
  2709     void run() {
  2710 
  2711       readLine();
  2712       skipSection();
  2713 
  2714       while (readSuccess()) {
  2715 
  2716         char c;
  2717         line >> c;
  2718 
  2719         std::string section, caption;
  2720         _reader_bits::readToken(line, section);
  2721         _reader_bits::readToken(line, caption);
  2722 
  2723         if (section == "nodes") {
  2724           _node_sections.push_back(caption);
  2725           _node_maps.push_back(std::vector<std::string>());
  2726           readMaps(_node_maps.back());
  2727           readLine(); skipSection();
  2728         } else if (section == "arcs" || section == "edges") {
  2729           _edge_sections.push_back(caption);
  2730           _arc_sections.push_back(section == "arcs");
  2731           _edge_maps.push_back(std::vector<std::string>());
  2732           readMaps(_edge_maps.back());
  2733           readLine(); skipSection();
  2734         } else if (section == "attributes") {
  2735           _attribute_sections.push_back(caption);
  2736           _attributes.push_back(std::vector<std::string>());
  2737           readAttributes(_attributes.back());
  2738         } else {
  2739           _extra_sections.push_back(section);
  2740           readLine(); skipSection();
  2741         }
  2742       }
  2743     }
  2744 
  2745     /// @}
  2746 
  2747   };
  2748 }
  2749 
  2750 #endif