COIN-OR::LEMON - Graph Library

source: lemon-1.2/lemon/lgf_reader.h @ 209:765619b7cbb2

Last change on this file since 209:765619b7cbb2 was 209:765619b7cbb2, checked in by Alpar Juttner <alpar@…>, 11 years ago

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1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2008
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
12 *
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
15 * purpose.
16 *
17 */
18
19///\ingroup lemon_io
20///\file
21///\brief \ref lgf-format "Lemon Graph Format" reader.
22
23
24#ifndef LEMON_LGF_READER_H
25#define LEMON_LGF_READER_H
26
27#include <iostream>
28#include <fstream>
29#include <sstream>
30
31#include <set>
32#include <map>
33
34#include <lemon/assert.h>
35#include <lemon/graph_utils.h>
36
37#include <lemon/lgf_writer.h>
38
39#include <lemon/concept_check.h>
40#include <lemon/concepts/maps.h>
41
42namespace lemon {
43
44  namespace _reader_bits {
45
46    template <typename Value>
47    struct DefaultConverter {
48      Value operator()(const std::string& str) {
49        std::istringstream is(str);
50        Value value;
51        is >> value;
52
53        char c;
54        if (is >> std::ws >> c) {
55          throw DataFormatError("Remaining characters in token");
56        }
57        return value;
58      }
59    };
60
61    template <>
62    struct DefaultConverter<std::string> {
63      std::string operator()(const std::string& str) {
64        return str;
65      }
66    };
67
68    template <typename _Item>
69    class MapStorageBase {
70    public:
71      typedef _Item Item;
72
73    public:
74      MapStorageBase() {}
75      virtual ~MapStorageBase() {}
76
77      virtual void set(const Item& item, const std::string& value) = 0;
78
79    };
80
81    template <typename _Item, typename _Map,
82              typename _Converter = DefaultConverter<typename _Map::Value> >
83    class MapStorage : public MapStorageBase<_Item> {
84    public:
85      typedef _Map Map;
86      typedef _Converter Converter;
87      typedef _Item Item;
88
89    private:
90      Map& _map;
91      Converter _converter;
92
93    public:
94      MapStorage(Map& map, const Converter& converter = Converter())
95        : _map(map), _converter(converter) {}
96      virtual ~MapStorage() {}
97
98      virtual void set(const Item& item ,const std::string& value) {
99        _map.set(item, _converter(value));
100      }
101    };
102
103    template <typename _Graph, bool _dir, typename _Map,
104              typename _Converter = DefaultConverter<typename _Map::Value> >
105    class GraphArcMapStorage : public MapStorageBase<typename _Graph::Edge> {
106    public:
107      typedef _Map Map;
108      typedef _Converter Converter;
109      typedef _Graph Graph;
110      typedef typename Graph::Edge Item;
111      static const bool dir = _dir;
112
113    private:
114      const Graph& _graph;
115      Map& _map;
116      Converter _converter;
117
118    public:
119      GraphArcMapStorage(const Graph& graph, Map& map,
120                         const Converter& converter = Converter())
121        : _graph(graph), _map(map), _converter(converter) {}
122      virtual ~GraphArcMapStorage() {}
123
124      virtual void set(const Item& item ,const std::string& value) {
125        _map.set(_graph.direct(item, dir), _converter(value));
126      }
127    };
128
129    class ValueStorageBase {
130    public:
131      ValueStorageBase() {}
132      virtual ~ValueStorageBase() {}
133
134      virtual void set(const std::string&) = 0;
135    };
136
137    template <typename _Value, typename _Converter = DefaultConverter<_Value> >
138    class ValueStorage : public ValueStorageBase {
139    public:
140      typedef _Value Value;
141      typedef _Converter Converter;
142
143    private:
144      Value& _value;
145      Converter _converter;
146
147    public:
148      ValueStorage(Value& value, const Converter& converter = Converter())
149         : _value(value), _converter(converter) {}
150
151      virtual void set(const std::string& value) {
152        _value = _converter(value);
153      }
154    };
155
156    template <typename Value>
157    struct MapLookUpConverter {
158      const std::map<std::string, Value>& _map;
159
160      MapLookUpConverter(const std::map<std::string, Value>& map)
161        : _map(map) {}
162
163      Value operator()(const std::string& str) {
164        typename std::map<std::string, Value>::const_iterator it =
165          _map.find(str);
166        if (it == _map.end()) {
167          std::ostringstream msg;
168          msg << "Item not found: " << str;
169          throw DataFormatError(msg.str().c_str());
170        }
171        return it->second;
172      }
173    };
174
175    template <typename Graph>
176    struct GraphArcLookUpConverter {
177      const Graph& _graph;
178      const std::map<std::string, typename Graph::Edge>& _map;
179
180      GraphArcLookUpConverter(const Graph& graph,
181                              const std::map<std::string,
182                                             typename Graph::Edge>& map)
183        : _graph(graph), _map(map) {}
184
185      typename Graph::Arc operator()(const std::string& str) {
186        if (str.empty() || (str[0] != '+' && str[0] != '-')) {
187          throw DataFormatError("Item must start with '+' or '-'");
188        }
189        typename std::map<std::string, typename Graph::Edge>
190          ::const_iterator it = _map.find(str.substr(1));
191        if (it == _map.end()) {
192          throw DataFormatError("Item not found");
193        }
194        return _graph.direct(it->second, str[0] == '+');
195      }
196    };
197
198    inline bool isWhiteSpace(char c) {
199      return c == ' ' || c == '\t' || c == '\v' ||
200        c == '\n' || c == '\r' || c == '\f';
201    }
202
203    inline bool isOct(char c) {
204      return '0' <= c && c <='7';
205    }
206
207    inline int valueOct(char c) {
208      LEMON_ASSERT(isOct(c), "The character is not octal.");
209      return c - '0';
210    }
211
212    inline bool isHex(char c) {
213      return ('0' <= c && c <= '9') ||
214        ('a' <= c && c <= 'z') ||
215        ('A' <= c && c <= 'Z');
216    }
217
218    inline int valueHex(char c) {
219      LEMON_ASSERT(isHex(c), "The character is not hexadecimal.");
220      if ('0' <= c && c <= '9') return c - '0';
221      if ('a' <= c && c <= 'z') return c - 'a' + 10;
222      return c - 'A' + 10;
223    }
224
225    inline bool isIdentifierFirstChar(char c) {
226      return ('a' <= c && c <= 'z') ||
227        ('A' <= c && c <= 'Z') || c == '_';
228    }
229
230    inline bool isIdentifierChar(char c) {
231      return isIdentifierFirstChar(c) ||
232        ('0' <= c && c <= '9');
233    }
234
235    inline char readEscape(std::istream& is) {
236      char c;
237      if (!is.get(c))
238        throw DataFormatError("Escape format error");
239
240      switch (c) {
241      case '\\':
242        return '\\';
243      case '\"':
244        return '\"';
245      case '\'':
246        return '\'';
247      case '\?':
248        return '\?';
249      case 'a':
250        return '\a';
251      case 'b':
252        return '\b';
253      case 'f':
254        return '\f';
255      case 'n':
256        return '\n';
257      case 'r':
258        return '\r';
259      case 't':
260        return '\t';
261      case 'v':
262        return '\v';
263      case 'x':
264        {
265          int code;
266          if (!is.get(c) || !isHex(c))
267            throw DataFormatError("Escape format error");
268          else if (code = valueHex(c), !is.get(c) || !isHex(c)) is.putback(c);
269          else code = code * 16 + valueHex(c);
270          return code;
271        }
272      default:
273        {
274          int code;
275          if (!isOct(c))
276            throw DataFormatError("Escape format error");
277          else if (code = valueOct(c), !is.get(c) || !isOct(c))
278            is.putback(c);
279          else if (code = code * 8 + valueOct(c), !is.get(c) || !isOct(c))
280            is.putback(c);
281          else code = code * 8 + valueOct(c);
282          return code;
283        }
284      }
285    }
286
287    inline std::istream& readToken(std::istream& is, std::string& str) {
288      std::ostringstream os;
289
290      char c;
291      is >> std::ws;
292
293      if (!is.get(c))
294        return is;
295
296      if (c == '\"') {
297        while (is.get(c) && c != '\"') {
298          if (c == '\\')
299            c = readEscape(is);
300          os << c;
301        }
302        if (!is)
303          throw DataFormatError("Quoted format error");
304      } else {
305        is.putback(c);
306        while (is.get(c) && !isWhiteSpace(c)) {
307          if (c == '\\')
308            c = readEscape(is);
309          os << c;
310        }
311        if (!is) {
312          is.clear();
313        } else {
314          is.putback(c);
315        }
316      }
317      str = os.str();
318      return is;
319    }
320
321    class Section {
322    public:
323      virtual ~Section() {}
324      virtual void process(std::istream& is, int& line_num) = 0;
325    };
326
327    template <typename Functor>
328    class LineSection : public Section {
329    private:
330
331      Functor _functor;
332
333    public:
334
335      LineSection(const Functor& functor) : _functor(functor) {}
336      virtual ~LineSection() {}
337
338      virtual void process(std::istream& is, int& line_num) {
339        char c;
340        std::string line;
341        while (is.get(c) && c != '@') {
342          if (c == '\n') {
343            ++line_num;
344          } else if (c == '#') {
345            getline(is, line);
346            ++line_num;
347          } else if (!isWhiteSpace(c)) {
348            is.putback(c);
349            getline(is, line);
350            _functor(line);
351            ++line_num;
352          }
353        }
354        if (is) is.putback(c);
355        else if (is.eof()) is.clear();
356      }
357    };
358
359    template <typename Functor>
360    class StreamSection : public Section {
361    private:
362
363      Functor _functor;
364
365    public:
366
367      StreamSection(const Functor& functor) : _functor(functor) {}
368      virtual ~StreamSection() {}
369
370      virtual void process(std::istream& is, int& line_num) {
371        _functor(is, line_num);
372        char c;
373        std::string line;
374        while (is.get(c) && c != '@') {
375          if (c == '\n') {
376            ++line_num;
377          } else if (!isWhiteSpace(c)) {
378            getline(is, line);
379            ++line_num;
380          }
381        }
382        if (is) is.putback(c);
383        else if (is.eof()) is.clear();
384      }
385    };
386
387  }
388
389  template <typename Digraph>
390  class DigraphReader;
391
392  template <typename Digraph>
393  DigraphReader<Digraph> digraphReader(std::istream& is, Digraph& digraph);
394
395  template <typename Digraph>
396  DigraphReader<Digraph> digraphReader(const std::string& fn, Digraph& digraph);
397
398  template <typename Digraph>
399  DigraphReader<Digraph> digraphReader(const char *fn, Digraph& digraph);
400
401  /// \ingroup lemon_io
402  ///
403  /// \brief \ref lgf-format "LGF" reader for directed graphs
404  ///
405  /// This utility reads an \ref lgf-format "LGF" file.
406  ///
407  /// The reading method does a batch processing. The user creates a
408  /// reader object, then various reading rules can be added to the
409  /// reader, and eventually the reading is executed with the \c run()
410  /// member function. A map reading rule can be added to the reader
411  /// with the \c nodeMap() or \c arcMap() members. An optional
412  /// converter parameter can also be added as a standard functor
413  /// converting from \c std::string to the value type of the map. If it
414  /// is set, it will determine how the tokens in the file should be
415  /// converted to the value type of the map. If the functor is not set,
416  /// then a default conversion will be used. One map can be read into
417  /// multiple map objects at the same time. The \c attribute(), \c
418  /// node() and \c arc() functions are used to add attribute reading
419  /// rules.
420  ///
421  ///\code
422  /// DigraphReader<Digraph>(std::cin, digraph).
423  ///   nodeMap("coordinates", coord_map).
424  ///   arcMap("capacity", cap_map).
425  ///   node("source", src).
426  ///   node("target", trg).
427  ///   attribute("caption", caption).
428  ///   run();
429  ///\endcode
430  ///
431  /// By default the reader uses the first section in the file of the
432  /// proper type. If a section has an optional name, then it can be
433  /// selected for reading by giving an optional name parameter to the
434  /// \c nodes(), \c arcs() or \c attributes() functions.
435  ///
436  /// The \c useNodes() and \c useArcs() functions are used to tell the reader
437  /// that the nodes or arcs should not be constructed (added to the
438  /// graph) during the reading, but instead the label map of the items
439  /// are given as a parameter of these functions. An
440  /// application of these functions is multipass reading, which is
441  /// important if two \c \@arcs sections must be read from the
442  /// file. In this case the first phase would read the node set and one
443  /// of the arc sets, while the second phase would read the second arc
444  /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
445  /// The previously read label node map should be passed to the \c
446  /// useNodes() functions. Another application of multipass reading when
447  /// paths are given as a node map or an arc map. 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 _Digraph>
451  class DigraphReader {
452  public:
453
454    typedef _Digraph Digraph;
455    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
456
457  private:
458
459
460    std::istream* _is;
461    bool local_is;
462
463    Digraph& _digraph;
464
465    std::string _nodes_caption;
466    std::string _arcs_caption;
467    std::string _attributes_caption;
468
469    typedef std::map<std::string, Node> NodeIndex;
470    NodeIndex _node_index;
471    typedef std::map<std::string, Arc> ArcIndex;
472    ArcIndex _arc_index;
473
474    typedef std::vector<std::pair<std::string,
475      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
476    NodeMaps _node_maps;
477
478    typedef std::vector<std::pair<std::string,
479      _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
480    ArcMaps _arc_maps;
481
482    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
483      Attributes;
484    Attributes _attributes;
485
486    bool _use_nodes;
487    bool _use_arcs;
488
489    bool _skip_nodes;
490    bool _skip_arcs;
491
492    int line_num;
493    std::istringstream line;
494
495  public:
496
497    /// \brief Constructor
498    ///
499    /// Construct a directed graph reader, which reads from the given
500    /// input stream.
501    DigraphReader(std::istream& is, Digraph& digraph)
502      : _is(&is), local_is(false), _digraph(digraph),
503        _use_nodes(false), _use_arcs(false),
504        _skip_nodes(false), _skip_arcs(false) {}
505
506    /// \brief Constructor
507    ///
508    /// Construct a directed graph reader, which reads from the given
509    /// file.
510    DigraphReader(const std::string& fn, Digraph& digraph)
511      : _is(new std::ifstream(fn.c_str())), local_is(true), _digraph(digraph),
512            _use_nodes(false), _use_arcs(false),
513        _skip_nodes(false), _skip_arcs(false) {}
514
515    /// \brief Constructor
516    ///
517    /// Construct a directed graph reader, which reads from the given
518    /// file.
519    DigraphReader(const char* fn, Digraph& digraph)
520      : _is(new std::ifstream(fn)), local_is(true), _digraph(digraph),
521            _use_nodes(false), _use_arcs(false),
522        _skip_nodes(false), _skip_arcs(false) {}
523
524    /// \brief Destructor
525    ~DigraphReader() {
526      for (typename NodeMaps::iterator it = _node_maps.begin();
527           it != _node_maps.end(); ++it) {
528        delete it->second;
529      }
530
531      for (typename ArcMaps::iterator it = _arc_maps.begin();
532           it != _arc_maps.end(); ++it) {
533        delete it->second;
534      }
535
536      for (typename Attributes::iterator it = _attributes.begin();
537           it != _attributes.end(); ++it) {
538        delete it->second;
539      }
540
541      if (local_is) {
542        delete _is;
543      }
544
545    }
546
547  private:
548
549    friend DigraphReader<Digraph> digraphReader<>(std::istream& is,
550                                                  Digraph& digraph);
551    friend DigraphReader<Digraph> digraphReader<>(const std::string& fn,
552                                                  Digraph& digraph);
553    friend DigraphReader<Digraph> digraphReader<>(const char *fn,
554                                                  Digraph& digraph);
555
556    DigraphReader(DigraphReader& other)
557      : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
558        _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
559        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
560
561      other._is = 0;
562      other.local_is = false;
563
564      _node_index.swap(other._node_index);
565      _arc_index.swap(other._arc_index);
566
567      _node_maps.swap(other._node_maps);
568      _arc_maps.swap(other._arc_maps);
569      _attributes.swap(other._attributes);
570
571      _nodes_caption = other._nodes_caption;
572      _arcs_caption = other._arcs_caption;
573      _attributes_caption = other._attributes_caption;
574
575    }
576
577    DigraphReader& operator=(const DigraphReader&);
578
579  public:
580
581    /// \name Reading rules
582    /// @{
583
584    /// \brief Node map reading rule
585    ///
586    /// Add a node map reading rule to the reader.
587    template <typename Map>
588    DigraphReader& nodeMap(const std::string& caption, Map& map) {
589      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
590      _reader_bits::MapStorageBase<Node>* storage =
591        new _reader_bits::MapStorage<Node, Map>(map);
592      _node_maps.push_back(std::make_pair(caption, storage));
593      return *this;
594    }
595
596    /// \brief Node map reading rule
597    ///
598    /// Add a node map reading rule with specialized converter to the
599    /// reader.
600    template <typename Map, typename Converter>
601    DigraphReader& nodeMap(const std::string& caption, Map& map,
602                           const Converter& converter = Converter()) {
603      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
604      _reader_bits::MapStorageBase<Node>* storage =
605        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
606      _node_maps.push_back(std::make_pair(caption, storage));
607      return *this;
608    }
609
610    /// \brief Arc map reading rule
611    ///
612    /// Add an arc map reading rule to the reader.
613    template <typename Map>
614    DigraphReader& arcMap(const std::string& caption, Map& map) {
615      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
616      _reader_bits::MapStorageBase<Arc>* storage =
617        new _reader_bits::MapStorage<Arc, Map>(map);
618      _arc_maps.push_back(std::make_pair(caption, storage));
619      return *this;
620    }
621
622    /// \brief Arc map reading rule
623    ///
624    /// Add an arc map reading rule with specialized converter to the
625    /// reader.
626    template <typename Map, typename Converter>
627    DigraphReader& arcMap(const std::string& caption, Map& map,
628                          const Converter& converter = Converter()) {
629      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
630      _reader_bits::MapStorageBase<Arc>* storage =
631        new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
632      _arc_maps.push_back(std::make_pair(caption, storage));
633      return *this;
634    }
635
636    /// \brief Attribute reading rule
637    ///
638    /// Add an attribute reading rule to the reader.
639    template <typename Value>
640    DigraphReader& attribute(const std::string& caption, Value& value) {
641      _reader_bits::ValueStorageBase* storage =
642        new _reader_bits::ValueStorage<Value>(value);
643      _attributes.insert(std::make_pair(caption, storage));
644      return *this;
645    }
646
647    /// \brief Attribute reading rule
648    ///
649    /// Add an attribute reading rule with specialized converter to the
650    /// reader.
651    template <typename Value, typename Converter>
652    DigraphReader& attribute(const std::string& caption, Value& value,
653                             const Converter& converter = Converter()) {
654      _reader_bits::ValueStorageBase* storage =
655        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
656      _attributes.insert(std::make_pair(caption, storage));
657      return *this;
658    }
659
660    /// \brief Node reading rule
661    ///
662    /// Add a node reading rule to reader.
663    DigraphReader& node(const std::string& caption, Node& node) {
664      typedef _reader_bits::MapLookUpConverter<Node> Converter;
665      Converter converter(_node_index);
666      _reader_bits::ValueStorageBase* storage =
667        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
668      _attributes.insert(std::make_pair(caption, storage));
669      return *this;
670    }
671
672    /// \brief Arc reading rule
673    ///
674    /// Add an arc reading rule to reader.
675    DigraphReader& arc(const std::string& caption, Arc& arc) {
676      typedef _reader_bits::MapLookUpConverter<Arc> Converter;
677      Converter converter(_arc_index);
678      _reader_bits::ValueStorageBase* storage =
679        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
680      _attributes.insert(std::make_pair(caption, storage));
681      return *this;
682    }
683
684    /// @}
685
686    /// \name Select section by name
687    /// @{
688
689    /// \brief Set \c \@nodes section to be read
690    ///
691    /// Set \c \@nodes section to be read
692    DigraphReader& nodes(const std::string& caption) {
693      _nodes_caption = caption;
694      return *this;
695    }
696
697    /// \brief Set \c \@arcs section to be read
698    ///
699    /// Set \c \@arcs section to be read
700    DigraphReader& arcs(const std::string& caption) {
701      _arcs_caption = caption;
702      return *this;
703    }
704
705    /// \brief Set \c \@attributes section to be read
706    ///
707    /// Set \c \@attributes section to be read
708    DigraphReader& attributes(const std::string& caption) {
709      _attributes_caption = caption;
710      return *this;
711    }
712
713    /// @}
714
715    /// \name Using previously constructed node or arc set
716    /// @{
717
718    /// \brief Use previously constructed node set
719    ///
720    /// Use previously constructed node set, and specify the node
721    /// label map.
722    template <typename Map>
723    DigraphReader& useNodes(const Map& map) {
724      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
725      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
726      _use_nodes = true;
727      _writer_bits::DefaultConverter<typename Map::Value> converter;
728      for (NodeIt n(_digraph); n != INVALID; ++n) {
729        _node_index.insert(std::make_pair(converter(map[n]), n));
730      }
731      return *this;
732    }
733
734    /// \brief Use previously constructed node set
735    ///
736    /// Use previously constructed node set, and specify the node
737    /// label map and a functor which converts the label map values to
738    /// \c std::string.
739    template <typename Map, typename Converter>
740    DigraphReader& useNodes(const Map& map,
741                            const Converter& converter = Converter()) {
742      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
743      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
744      _use_nodes = true;
745      for (NodeIt n(_digraph); n != INVALID; ++n) {
746        _node_index.insert(std::make_pair(converter(map[n]), n));
747      }
748      return *this;
749    }
750
751    /// \brief Use previously constructed arc set
752    ///
753    /// Use previously constructed arc set, and specify the arc
754    /// label map.
755    template <typename Map>
756    DigraphReader& useArcs(const Map& map) {
757      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
758      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
759      _use_arcs = true;
760      _writer_bits::DefaultConverter<typename Map::Value> converter;
761      for (ArcIt a(_digraph); a != INVALID; ++a) {
762        _arc_index.insert(std::make_pair(converter(map[a]), a));
763      }
764      return *this;
765    }
766
767    /// \brief Use previously constructed arc set
768    ///
769    /// Use previously constructed arc set, and specify the arc
770    /// label map and a functor which converts the label map values to
771    /// \c std::string.
772    template <typename Map, typename Converter>
773    DigraphReader& useArcs(const Map& map,
774                           const Converter& converter = Converter()) {
775      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
776      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
777      _use_arcs = true;
778      for (ArcIt a(_digraph); a != INVALID; ++a) {
779        _arc_index.insert(std::make_pair(converter(map[a]), a));
780      }
781      return *this;
782    }
783
784    /// \brief Skips the reading of node section
785    ///
786    /// Omit the reading of the node section. This implies that each node
787    /// map reading rule will be abandoned, and the nodes of the graph
788    /// will not be constructed, which usually cause that the arc set
789    /// could not be read due to lack of node name resolving.
790    /// Therefore \c skipArcs() function should also be used, or
791    /// \c useNodes() should be used to specify the label of the nodes.
792    DigraphReader& skipNodes() {
793      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
794      _skip_nodes = true;
795      return *this;
796    }
797
798    /// \brief Skips the reading of arc section
799    ///
800    /// Omit the reading of the arc section. This implies that each arc
801    /// map reading rule will be abandoned, and the arcs of the graph
802    /// will not be constructed.
803    DigraphReader& skipArcs() {
804      LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
805      _skip_arcs = true;
806      return *this;
807    }
808
809    /// @}
810
811  private:
812
813    bool readLine() {
814      std::string str;
815      while(++line_num, std::getline(*_is, str)) {
816        line.clear(); line.str(str);
817        char c;
818        if (line >> std::ws >> c && c != '#') {
819          line.putback(c);
820          return true;
821        }
822      }
823      return false;
824    }
825
826    bool readSuccess() {
827      return static_cast<bool>(*_is);
828    }
829
830    void skipSection() {
831      char c;
832      while (readSuccess() && line >> c && c != '@') {
833        readLine();
834      }
835      line.putback(c);
836    }
837
838    void readNodes() {
839
840      std::vector<int> map_index(_node_maps.size());
841      int map_num, label_index;
842
843      char c;
844      if (!readLine() || !(line >> c) || c == '@') {
845        if (readSuccess() && line) line.putback(c);
846        if (!_node_maps.empty())
847          throw DataFormatError("Cannot find map names");
848        return;
849      }
850      line.putback(c);
851
852      {
853        std::map<std::string, int> maps;
854
855        std::string map;
856        int index = 0;
857        while (_reader_bits::readToken(line, map)) {
858          if (maps.find(map) != maps.end()) {
859            std::ostringstream msg;
860            msg << "Multiple occurence of node map: " << map;
861            throw DataFormatError(msg.str().c_str());
862          }
863          maps.insert(std::make_pair(map, index));
864          ++index;
865        }
866
867        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
868          std::map<std::string, int>::iterator jt =
869            maps.find(_node_maps[i].first);
870          if (jt == maps.end()) {
871            std::ostringstream msg;
872            msg << "Map not found in file: " << _node_maps[i].first;
873            throw DataFormatError(msg.str().c_str());
874          }
875          map_index[i] = jt->second;
876        }
877
878        {
879          std::map<std::string, int>::iterator jt = maps.find("label");
880          if (jt != maps.end()) {
881            label_index = jt->second;
882          } else {
883            label_index = -1;
884          }
885        }
886        map_num = maps.size();
887      }
888
889      while (readLine() && line >> c && c != '@') {
890        line.putback(c);
891
892        std::vector<std::string> tokens(map_num);
893        for (int i = 0; i < map_num; ++i) {
894          if (!_reader_bits::readToken(line, tokens[i])) {
895            std::ostringstream msg;
896            msg << "Column not found (" << i + 1 << ")";
897            throw DataFormatError(msg.str().c_str());
898          }
899        }
900        if (line >> std::ws >> c)
901          throw DataFormatError("Extra character on the end of line");
902
903        Node n;
904        if (!_use_nodes) {
905          n = _digraph.addNode();
906          if (label_index != -1)
907            _node_index.insert(std::make_pair(tokens[label_index], n));
908        } else {
909          if (label_index == -1)
910            throw DataFormatError("Label map not found in file");
911          typename std::map<std::string, Node>::iterator it =
912            _node_index.find(tokens[label_index]);
913          if (it == _node_index.end()) {
914            std::ostringstream msg;
915            msg << "Node with label not found: " << tokens[label_index];
916            throw DataFormatError(msg.str().c_str());
917          }
918          n = it->second;
919        }
920
921        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
922          _node_maps[i].second->set(n, tokens[map_index[i]]);
923        }
924
925      }
926      if (readSuccess()) {
927        line.putback(c);
928      }
929    }
930
931    void readArcs() {
932
933      std::vector<int> map_index(_arc_maps.size());
934      int map_num, label_index;
935
936      char c;
937      if (!readLine() || !(line >> c) || c == '@') {
938        if (readSuccess() && line) line.putback(c);
939        if (!_arc_maps.empty())
940          throw DataFormatError("Cannot find map names");
941        return;
942      }
943      line.putback(c);
944
945      {
946        std::map<std::string, int> maps;
947
948        std::string map;
949        int index = 0;
950        while (_reader_bits::readToken(line, map)) {
951          if (maps.find(map) != maps.end()) {
952            std::ostringstream msg;
953            msg << "Multiple occurence of arc map: " << map;
954            throw DataFormatError(msg.str().c_str());
955          }
956          maps.insert(std::make_pair(map, index));
957          ++index;
958        }
959
960        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
961          std::map<std::string, int>::iterator jt =
962            maps.find(_arc_maps[i].first);
963          if (jt == maps.end()) {
964            std::ostringstream msg;
965            msg << "Map not found in file: " << _arc_maps[i].first;
966            throw DataFormatError(msg.str().c_str());
967          }
968          map_index[i] = jt->second;
969        }
970
971        {
972          std::map<std::string, int>::iterator jt = maps.find("label");
973          if (jt != maps.end()) {
974            label_index = jt->second;
975          } else {
976            label_index = -1;
977          }
978        }
979        map_num = maps.size();
980      }
981
982      while (readLine() && line >> c && c != '@') {
983        line.putback(c);
984
985        std::string source_token;
986        std::string target_token;
987
988        if (!_reader_bits::readToken(line, source_token))
989          throw DataFormatError("Source not found");
990
991        if (!_reader_bits::readToken(line, target_token))
992          throw DataFormatError("Target not found");
993
994        std::vector<std::string> tokens(map_num);
995        for (int i = 0; i < map_num; ++i) {
996          if (!_reader_bits::readToken(line, tokens[i])) {
997            std::ostringstream msg;
998            msg << "Column not found (" << i + 1 << ")";
999            throw DataFormatError(msg.str().c_str());
1000          }
1001        }
1002        if (line >> std::ws >> c)
1003          throw DataFormatError("Extra character on the end of line");
1004
1005        Arc a;
1006        if (!_use_arcs) {
1007
1008          typename NodeIndex::iterator it;
1009
1010          it = _node_index.find(source_token);
1011          if (it == _node_index.end()) {
1012            std::ostringstream msg;
1013            msg << "Item not found: " << source_token;
1014            throw DataFormatError(msg.str().c_str());
1015          }
1016          Node source = it->second;
1017
1018          it = _node_index.find(target_token);
1019          if (it == _node_index.end()) {
1020            std::ostringstream msg;
1021            msg << "Item not found: " << target_token;
1022            throw DataFormatError(msg.str().c_str());
1023          }
1024          Node target = it->second;
1025
1026          a = _digraph.addArc(source, target);
1027          if (label_index != -1)
1028            _arc_index.insert(std::make_pair(tokens[label_index], a));
1029        } else {
1030          if (label_index == -1)
1031            throw DataFormatError("Label map not found in file");
1032          typename std::map<std::string, Arc>::iterator it =
1033            _arc_index.find(tokens[label_index]);
1034          if (it == _arc_index.end()) {
1035            std::ostringstream msg;
1036            msg << "Arc with label not found: " << tokens[label_index];
1037            throw DataFormatError(msg.str().c_str());
1038          }
1039          a = it->second;
1040        }
1041
1042        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
1043          _arc_maps[i].second->set(a, tokens[map_index[i]]);
1044        }
1045
1046      }
1047      if (readSuccess()) {
1048        line.putback(c);
1049      }
1050    }
1051
1052    void readAttributes() {
1053
1054      std::set<std::string> read_attr;
1055
1056      char c;
1057      while (readLine() && line >> c && c != '@') {
1058        line.putback(c);
1059
1060        std::string attr, token;
1061        if (!_reader_bits::readToken(line, attr))
1062          throw DataFormatError("Attribute name not found");
1063        if (!_reader_bits::readToken(line, token))
1064          throw DataFormatError("Attribute value not found");
1065        if (line >> c)
1066          throw DataFormatError("Extra character on the end of line");
1067
1068        {
1069          std::set<std::string>::iterator it = read_attr.find(attr);
1070          if (it != read_attr.end()) {
1071            std::ostringstream msg;
1072            msg << "Multiple occurence of attribute " << attr;
1073            throw DataFormatError(msg.str().c_str());
1074          }
1075          read_attr.insert(attr);
1076        }
1077
1078        {
1079          typename Attributes::iterator it = _attributes.lower_bound(attr);
1080          while (it != _attributes.end() && it->first == attr) {
1081            it->second->set(token);
1082            ++it;
1083          }
1084        }
1085
1086      }
1087      if (readSuccess()) {
1088        line.putback(c);
1089      }
1090      for (typename Attributes::iterator it = _attributes.begin();
1091           it != _attributes.end(); ++it) {
1092        if (read_attr.find(it->first) == read_attr.end()) {
1093          std::ostringstream msg;
1094          msg << "Attribute not found in file: " << it->first;
1095          throw DataFormatError(msg.str().c_str());
1096        }
1097      }
1098    }
1099
1100  public:
1101
1102    /// \name Execution of the reader
1103    /// @{
1104
1105    /// \brief Start the batch processing
1106    ///
1107    /// This function starts the batch processing
1108    void run() {
1109      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1110      if (!*_is) {
1111        throw DataFormatError("Cannot find file");
1112      }
1113
1114      bool nodes_done = _skip_nodes;
1115      bool arcs_done = _skip_arcs;
1116      bool attributes_done = false;
1117
1118      line_num = 0;
1119      readLine();
1120      skipSection();
1121
1122      while (readSuccess()) {
1123        try {
1124          char c;
1125          std::string section, caption;
1126          line >> c;
1127          _reader_bits::readToken(line, section);
1128          _reader_bits::readToken(line, caption);
1129
1130          if (line >> c)
1131            throw DataFormatError("Extra character on the end of line");
1132
1133          if (section == "nodes" && !nodes_done) {
1134            if (_nodes_caption.empty() || _nodes_caption == caption) {
1135              readNodes();
1136              nodes_done = true;
1137            }
1138          } else if ((section == "arcs" || section == "edges") &&
1139                     !arcs_done) {
1140            if (_arcs_caption.empty() || _arcs_caption == caption) {
1141              readArcs();
1142              arcs_done = true;
1143            }
1144          } else if (section == "attributes" && !attributes_done) {
1145            if (_attributes_caption.empty() || _attributes_caption == caption) {
1146              readAttributes();
1147              attributes_done = true;
1148            }
1149          } else {
1150            readLine();
1151            skipSection();
1152          }
1153        } catch (DataFormatError& error) {
1154          error.line(line_num);
1155          throw;
1156        }
1157      }
1158
1159      if (!nodes_done) {
1160        throw DataFormatError("Section @nodes not found");
1161      }
1162
1163      if (!arcs_done) {
1164        throw DataFormatError("Section @arcs not found");
1165      }
1166
1167      if (!attributes_done && !_attributes.empty()) {
1168        throw DataFormatError("Section @attributes not found");
1169      }
1170
1171    }
1172
1173    /// @}
1174
1175  };
1176
1177  /// \brief Return a \ref DigraphReader class
1178  ///
1179  /// This function just returns a \ref DigraphReader class.
1180  /// \relates DigraphReader
1181  template <typename Digraph>
1182  DigraphReader<Digraph> digraphReader(std::istream& is, Digraph& digraph) {
1183    DigraphReader<Digraph> tmp(is, digraph);
1184    return tmp;
1185  }
1186
1187  /// \brief Return a \ref DigraphReader class
1188  ///
1189  /// This function just returns a \ref DigraphReader class.
1190  /// \relates DigraphReader
1191  template <typename Digraph>
1192  DigraphReader<Digraph> digraphReader(const std::string& fn,
1193                                       Digraph& digraph) {
1194    DigraphReader<Digraph> tmp(fn, digraph);
1195    return tmp;
1196  }
1197
1198  /// \brief Return a \ref DigraphReader class
1199  ///
1200  /// This function just returns a \ref DigraphReader class.
1201  /// \relates DigraphReader
1202  template <typename Digraph>
1203  DigraphReader<Digraph> digraphReader(const char* fn, Digraph& digraph) {
1204    DigraphReader<Digraph> tmp(fn, digraph);
1205    return tmp;
1206  }
1207
1208  template <typename Graph>
1209  class GraphReader;
1210
1211  template <typename Graph>
1212  GraphReader<Graph> graphReader(std::istream& is, Graph& graph);
1213
1214  template <typename Graph>
1215  GraphReader<Graph> graphReader(const std::string& fn, Graph& graph);
1216
1217  template <typename Graph>
1218  GraphReader<Graph> graphReader(const char *fn, Graph& graph);
1219
1220  /// \ingroup lemon_io
1221  ///
1222  /// \brief \ref lgf-format "LGF" reader for undirected graphs
1223  ///
1224  /// This utility reads an \ref lgf-format "LGF" file.
1225  ///
1226  /// It can be used almost the same way as \c DigraphReader.
1227  /// The only difference is that this class can handle edges and
1228  /// edge maps as well as arcs and arc maps.
1229  ///
1230  /// The columns in the \c \@edges (or \c \@arcs) section are the
1231  /// edge maps. However, if there are two maps with the same name
1232  /// prefixed with \c '+' and \c '-', then these can be read into an
1233  /// arc map.  Similarly, an attribute can be read into an arc, if
1234  /// it's value is an edge label prefixed with \c '+' or \c '-'.
1235  template <typename _Graph>
1236  class GraphReader {
1237  public:
1238
1239    typedef _Graph Graph;
1240    TEMPLATE_GRAPH_TYPEDEFS(Graph);
1241
1242  private:
1243
1244    std::istream* _is;
1245    bool local_is;
1246
1247    Graph& _graph;
1248
1249    std::string _nodes_caption;
1250    std::string _edges_caption;
1251    std::string _attributes_caption;
1252
1253    typedef std::map<std::string, Node> NodeIndex;
1254    NodeIndex _node_index;
1255    typedef std::map<std::string, Edge> EdgeIndex;
1256    EdgeIndex _edge_index;
1257
1258    typedef std::vector<std::pair<std::string,
1259      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
1260    NodeMaps _node_maps;
1261
1262    typedef std::vector<std::pair<std::string,
1263      _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
1264    EdgeMaps _edge_maps;
1265
1266    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
1267      Attributes;
1268    Attributes _attributes;
1269
1270    bool _use_nodes;
1271    bool _use_edges;
1272
1273    bool _skip_nodes;
1274    bool _skip_edges;
1275
1276    int line_num;
1277    std::istringstream line;
1278
1279  public:
1280
1281    /// \brief Constructor
1282    ///
1283    /// Construct an undirected graph reader, which reads from the given
1284    /// input stream.
1285    GraphReader(std::istream& is, Graph& graph)
1286      : _is(&is), local_is(false), _graph(graph),
1287        _use_nodes(false), _use_edges(false),
1288        _skip_nodes(false), _skip_edges(false) {}
1289
1290    /// \brief Constructor
1291    ///
1292    /// Construct an undirected graph reader, which reads from the given
1293    /// file.
1294    GraphReader(const std::string& fn, Graph& graph)
1295      : _is(new std::ifstream(fn.c_str())), local_is(true), _graph(graph),
1296            _use_nodes(false), _use_edges(false),
1297        _skip_nodes(false), _skip_edges(false) {}
1298
1299    /// \brief Constructor
1300    ///
1301    /// Construct an undirected graph reader, which reads from the given
1302    /// file.
1303    GraphReader(const char* fn, Graph& graph)
1304      : _is(new std::ifstream(fn)), local_is(true), _graph(graph),
1305            _use_nodes(false), _use_edges(false),
1306        _skip_nodes(false), _skip_edges(false) {}
1307
1308    /// \brief Destructor
1309    ~GraphReader() {
1310      for (typename NodeMaps::iterator it = _node_maps.begin();
1311           it != _node_maps.end(); ++it) {
1312        delete it->second;
1313      }
1314
1315      for (typename EdgeMaps::iterator it = _edge_maps.begin();
1316           it != _edge_maps.end(); ++it) {
1317        delete it->second;
1318      }
1319
1320      for (typename Attributes::iterator it = _attributes.begin();
1321           it != _attributes.end(); ++it) {
1322        delete it->second;
1323      }
1324
1325      if (local_is) {
1326        delete _is;
1327      }
1328
1329    }
1330
1331  private:
1332    friend GraphReader<Graph> graphReader<>(std::istream& is, Graph& graph);
1333    friend GraphReader<Graph> graphReader<>(const std::string& fn,
1334                                            Graph& graph);
1335    friend GraphReader<Graph> graphReader<>(const char *fn, Graph& graph);
1336
1337    GraphReader(GraphReader& other)
1338      : _is(other._is), local_is(other.local_is), _graph(other._graph),
1339        _use_nodes(other._use_nodes), _use_edges(other._use_edges),
1340        _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
1341
1342      other._is = 0;
1343      other.local_is = false;
1344
1345      _node_index.swap(other._node_index);
1346      _edge_index.swap(other._edge_index);
1347
1348      _node_maps.swap(other._node_maps);
1349      _edge_maps.swap(other._edge_maps);
1350      _attributes.swap(other._attributes);
1351
1352      _nodes_caption = other._nodes_caption;
1353      _edges_caption = other._edges_caption;
1354      _attributes_caption = other._attributes_caption;
1355
1356    }
1357
1358    GraphReader& operator=(const GraphReader&);
1359
1360  public:
1361
1362    /// \name Reading rules
1363    /// @{
1364
1365    /// \brief Node map reading rule
1366    ///
1367    /// Add a node map reading rule to the reader.
1368    template <typename Map>
1369    GraphReader& nodeMap(const std::string& caption, Map& map) {
1370      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1371      _reader_bits::MapStorageBase<Node>* storage =
1372        new _reader_bits::MapStorage<Node, Map>(map);
1373      _node_maps.push_back(std::make_pair(caption, storage));
1374      return *this;
1375    }
1376
1377    /// \brief Node map reading rule
1378    ///
1379    /// Add a node map reading rule with specialized converter to the
1380    /// reader.
1381    template <typename Map, typename Converter>
1382    GraphReader& nodeMap(const std::string& caption, Map& map,
1383                           const Converter& converter = Converter()) {
1384      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1385      _reader_bits::MapStorageBase<Node>* storage =
1386        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
1387      _node_maps.push_back(std::make_pair(caption, storage));
1388      return *this;
1389    }
1390
1391    /// \brief Edge map reading rule
1392    ///
1393    /// Add an edge map reading rule to the reader.
1394    template <typename Map>
1395    GraphReader& edgeMap(const std::string& caption, Map& map) {
1396      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1397      _reader_bits::MapStorageBase<Edge>* storage =
1398        new _reader_bits::MapStorage<Edge, Map>(map);
1399      _edge_maps.push_back(std::make_pair(caption, storage));
1400      return *this;
1401    }
1402
1403    /// \brief Edge map reading rule
1404    ///
1405    /// Add an edge map reading rule with specialized converter to the
1406    /// reader.
1407    template <typename Map, typename Converter>
1408    GraphReader& edgeMap(const std::string& caption, Map& map,
1409                          const Converter& converter = Converter()) {
1410      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1411      _reader_bits::MapStorageBase<Edge>* storage =
1412        new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
1413      _edge_maps.push_back(std::make_pair(caption, storage));
1414      return *this;
1415    }
1416
1417    /// \brief Arc map reading rule
1418    ///
1419    /// Add an arc map reading rule to the reader.
1420    template <typename Map>
1421    GraphReader& arcMap(const std::string& caption, Map& map) {
1422      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1423      _reader_bits::MapStorageBase<Edge>* forward_storage =
1424        new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
1425      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1426      _reader_bits::MapStorageBase<Edge>* backward_storage =
1427        new _reader_bits::GraphArcMapStorage<Graph, false, Map>(_graph, map);
1428      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1429      return *this;
1430    }
1431
1432    /// \brief Arc map reading rule
1433    ///
1434    /// Add an arc map reading rule with specialized converter to the
1435    /// reader.
1436    template <typename Map, typename Converter>
1437    GraphReader& arcMap(const std::string& caption, Map& map,
1438                          const Converter& converter = Converter()) {
1439      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1440      _reader_bits::MapStorageBase<Edge>* forward_storage =
1441        new _reader_bits::GraphArcMapStorage<Graph, true, Map, Converter>
1442        (_graph, map, converter);
1443      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1444      _reader_bits::MapStorageBase<Edge>* backward_storage =
1445        new _reader_bits::GraphArcMapStorage<Graph, false, Map, Converter>
1446        (_graph, map, converter);
1447      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1448      return *this;
1449    }
1450
1451    /// \brief Attribute reading rule
1452    ///
1453    /// Add an attribute reading rule to the reader.
1454    template <typename Value>
1455    GraphReader& attribute(const std::string& caption, Value& value) {
1456      _reader_bits::ValueStorageBase* storage =
1457        new _reader_bits::ValueStorage<Value>(value);
1458      _attributes.insert(std::make_pair(caption, storage));
1459      return *this;
1460    }
1461
1462    /// \brief Attribute reading rule
1463    ///
1464    /// Add an attribute reading rule with specialized converter to the
1465    /// reader.
1466    template <typename Value, typename Converter>
1467    GraphReader& attribute(const std::string& caption, Value& value,
1468                             const Converter& converter = Converter()) {
1469      _reader_bits::ValueStorageBase* storage =
1470        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
1471      _attributes.insert(std::make_pair(caption, storage));
1472      return *this;
1473    }
1474
1475    /// \brief Node reading rule
1476    ///
1477    /// Add a node reading rule to reader.
1478    GraphReader& node(const std::string& caption, Node& node) {
1479      typedef _reader_bits::MapLookUpConverter<Node> Converter;
1480      Converter converter(_node_index);
1481      _reader_bits::ValueStorageBase* storage =
1482        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
1483      _attributes.insert(std::make_pair(caption, storage));
1484      return *this;
1485    }
1486
1487    /// \brief Edge reading rule
1488    ///
1489    /// Add an edge reading rule to reader.
1490    GraphReader& edge(const std::string& caption, Edge& edge) {
1491      typedef _reader_bits::MapLookUpConverter<Edge> Converter;
1492      Converter converter(_edge_index);
1493      _reader_bits::ValueStorageBase* storage =
1494        new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
1495      _attributes.insert(std::make_pair(caption, storage));
1496      return *this;
1497    }
1498
1499    /// \brief Arc reading rule
1500    ///
1501    /// Add an arc reading rule to reader.
1502    GraphReader& arc(const std::string& caption, Arc& arc) {
1503      typedef _reader_bits::GraphArcLookUpConverter<Graph> Converter;
1504      Converter converter(_graph, _edge_index);
1505      _reader_bits::ValueStorageBase* storage =
1506        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
1507      _attributes.insert(std::make_pair(caption, storage));
1508      return *this;
1509    }
1510
1511    /// @}
1512
1513    /// \name Select section by name
1514    /// @{
1515
1516    /// \brief Set \c \@nodes section to be read
1517    ///
1518    /// Set \c \@nodes section to be read.
1519    GraphReader& nodes(const std::string& caption) {
1520      _nodes_caption = caption;
1521      return *this;
1522    }
1523
1524    /// \brief Set \c \@edges section to be read
1525    ///
1526    /// Set \c \@edges section to be read.
1527    GraphReader& edges(const std::string& caption) {
1528      _edges_caption = caption;
1529      return *this;
1530    }
1531
1532    /// \brief Set \c \@attributes section to be read
1533    ///
1534    /// Set \c \@attributes section to be read.
1535    GraphReader& attributes(const std::string& caption) {
1536      _attributes_caption = caption;
1537      return *this;
1538    }
1539
1540    /// @}
1541
1542    /// \name Using previously constructed node or edge set
1543    /// @{
1544
1545    /// \brief Use previously constructed node set
1546    ///
1547    /// Use previously constructed node set, and specify the node
1548    /// label map.
1549    template <typename Map>
1550    GraphReader& useNodes(const Map& map) {
1551      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1552      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1553      _use_nodes = true;
1554      _writer_bits::DefaultConverter<typename Map::Value> converter;
1555      for (NodeIt n(_graph); n != INVALID; ++n) {
1556        _node_index.insert(std::make_pair(converter(map[n]), n));
1557      }
1558      return *this;
1559    }
1560
1561    /// \brief Use previously constructed node set
1562    ///
1563    /// Use previously constructed node set, and specify the node
1564    /// label map and a functor which converts the label map values to
1565    /// \c std::string.
1566    template <typename Map, typename Converter>
1567    GraphReader& useNodes(const Map& map,
1568                            const Converter& converter = Converter()) {
1569      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1570      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1571      _use_nodes = true;
1572      for (NodeIt n(_graph); n != INVALID; ++n) {
1573        _node_index.insert(std::make_pair(converter(map[n]), n));
1574      }
1575      return *this;
1576    }
1577
1578    /// \brief Use previously constructed edge set
1579    ///
1580    /// Use previously constructed edge set, and specify the edge
1581    /// label map.
1582    template <typename Map>
1583    GraphReader& useEdges(const Map& map) {
1584      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1585      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1586      _use_edges = true;
1587      _writer_bits::DefaultConverter<typename Map::Value> converter;
1588      for (EdgeIt a(_graph); a != INVALID; ++a) {
1589        _edge_index.insert(std::make_pair(converter(map[a]), a));
1590      }
1591      return *this;
1592    }
1593
1594    /// \brief Use previously constructed edge set
1595    ///
1596    /// Use previously constructed edge set, and specify the edge
1597    /// label map and a functor which converts the label map values to
1598    /// \c std::string.
1599    template <typename Map, typename Converter>
1600    GraphReader& useEdges(const Map& map,
1601                            const Converter& converter = Converter()) {
1602      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1603      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1604      _use_edges = true;
1605      for (EdgeIt a(_graph); a != INVALID; ++a) {
1606        _edge_index.insert(std::make_pair(converter(map[a]), a));
1607      }
1608      return *this;
1609    }
1610
1611    /// \brief Skip the reading of node section
1612    ///
1613    /// Omit the reading of the node section. This implies that each node
1614    /// map reading rule will be abandoned, and the nodes of the graph
1615    /// will not be constructed, which usually cause that the edge set
1616    /// could not be read due to lack of node name
1617    /// could not be read due to lack of node name resolving.
1618    /// Therefore \c skipEdges() function should also be used, or
1619    /// \c useNodes() should be used to specify the label of the nodes.
1620    GraphReader& skipNodes() {
1621      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
1622      _skip_nodes = true;
1623      return *this;
1624    }
1625
1626    /// \brief Skip the reading of edge section
1627    ///
1628    /// Omit the reading of the edge section. This implies that each edge
1629    /// map reading rule will be abandoned, and the edges of the graph
1630    /// will not be constructed.
1631    GraphReader& skipEdges() {
1632      LEMON_ASSERT(!_skip_edges, "Skip edges already set");
1633      _skip_edges = true;
1634      return *this;
1635    }
1636
1637    /// @}
1638
1639  private:
1640
1641    bool readLine() {
1642      std::string str;
1643      while(++line_num, std::getline(*_is, str)) {
1644        line.clear(); line.str(str);
1645        char c;
1646        if (line >> std::ws >> c && c != '#') {
1647          line.putback(c);
1648          return true;
1649        }
1650      }
1651      return false;
1652    }
1653
1654    bool readSuccess() {
1655      return static_cast<bool>(*_is);
1656    }
1657
1658    void skipSection() {
1659      char c;
1660      while (readSuccess() && line >> c && c != '@') {
1661        readLine();
1662      }
1663      line.putback(c);
1664    }
1665
1666    void readNodes() {
1667
1668      std::vector<int> map_index(_node_maps.size());
1669      int map_num, label_index;
1670
1671      char c;
1672      if (!readLine() || !(line >> c) || c == '@') {
1673        if (readSuccess() && line) line.putback(c);
1674        if (!_node_maps.empty())
1675          throw DataFormatError("Cannot find map names");
1676        return;
1677      }
1678      line.putback(c);
1679
1680      {
1681        std::map<std::string, int> maps;
1682
1683        std::string map;
1684        int index = 0;
1685        while (_reader_bits::readToken(line, map)) {
1686          if (maps.find(map) != maps.end()) {
1687            std::ostringstream msg;
1688            msg << "Multiple occurence of node map: " << map;
1689            throw DataFormatError(msg.str().c_str());
1690          }
1691          maps.insert(std::make_pair(map, index));
1692          ++index;
1693        }
1694
1695        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1696          std::map<std::string, int>::iterator jt =
1697            maps.find(_node_maps[i].first);
1698          if (jt == maps.end()) {
1699            std::ostringstream msg;
1700            msg << "Map not found in file: " << _node_maps[i].first;
1701            throw DataFormatError(msg.str().c_str());
1702          }
1703          map_index[i] = jt->second;
1704        }
1705
1706        {
1707          std::map<std::string, int>::iterator jt = maps.find("label");
1708          if (jt != maps.end()) {
1709            label_index = jt->second;
1710          } else {
1711            label_index = -1;
1712          }
1713        }
1714        map_num = maps.size();
1715      }
1716
1717      while (readLine() && line >> c && c != '@') {
1718        line.putback(c);
1719
1720        std::vector<std::string> tokens(map_num);
1721        for (int i = 0; i < map_num; ++i) {
1722          if (!_reader_bits::readToken(line, tokens[i])) {
1723            std::ostringstream msg;
1724            msg << "Column not found (" << i + 1 << ")";
1725            throw DataFormatError(msg.str().c_str());
1726          }
1727        }
1728        if (line >> std::ws >> c)
1729          throw DataFormatError("Extra character on the end of line");
1730
1731        Node n;
1732        if (!_use_nodes) {
1733          n = _graph.addNode();
1734          if (label_index != -1)
1735            _node_index.insert(std::make_pair(tokens[label_index], n));
1736        } else {
1737          if (label_index == -1)
1738            throw DataFormatError("Label map not found in file");
1739          typename std::map<std::string, Node>::iterator it =
1740            _node_index.find(tokens[label_index]);
1741          if (it == _node_index.end()) {
1742            std::ostringstream msg;
1743            msg << "Node with label not found: " << tokens[label_index];
1744            throw DataFormatError(msg.str().c_str());
1745          }
1746          n = it->second;
1747        }
1748
1749        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1750          _node_maps[i].second->set(n, tokens[map_index[i]]);
1751        }
1752
1753      }
1754      if (readSuccess()) {
1755        line.putback(c);
1756      }
1757    }
1758
1759    void readEdges() {
1760
1761      std::vector<int> map_index(_edge_maps.size());
1762      int map_num, label_index;
1763
1764      char c;
1765      if (!readLine() || !(line >> c) || c == '@') {
1766        if (readSuccess() && line) line.putback(c);
1767        if (!_edge_maps.empty())
1768          throw DataFormatError("Cannot find map names");
1769        return;
1770      }
1771      line.putback(c);
1772
1773      {
1774        std::map<std::string, int> maps;
1775
1776        std::string map;
1777        int index = 0;
1778        while (_reader_bits::readToken(line, map)) {
1779          if (maps.find(map) != maps.end()) {
1780            std::ostringstream msg;
1781            msg << "Multiple occurence of edge map: " << map;
1782            throw DataFormatError(msg.str().c_str());
1783          }
1784          maps.insert(std::make_pair(map, index));
1785          ++index;
1786        }
1787
1788        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1789          std::map<std::string, int>::iterator jt =
1790            maps.find(_edge_maps[i].first);
1791          if (jt == maps.end()) {
1792            std::ostringstream msg;
1793            msg << "Map not found in file: " << _edge_maps[i].first;
1794            throw DataFormatError(msg.str().c_str());
1795          }
1796          map_index[i] = jt->second;
1797        }
1798
1799        {
1800          std::map<std::string, int>::iterator jt = maps.find("label");
1801          if (jt != maps.end()) {
1802            label_index = jt->second;
1803          } else {
1804            label_index = -1;
1805          }
1806        }
1807        map_num = maps.size();
1808      }
1809
1810      while (readLine() && line >> c && c != '@') {
1811        line.putback(c);
1812
1813        std::string source_token;
1814        std::string target_token;
1815
1816        if (!_reader_bits::readToken(line, source_token))
1817          throw DataFormatError("Node u not found");
1818
1819        if (!_reader_bits::readToken(line, target_token))
1820          throw DataFormatError("Node v not found");
1821
1822        std::vector<std::string> tokens(map_num);
1823        for (int i = 0; i < map_num; ++i) {
1824          if (!_reader_bits::readToken(line, tokens[i])) {
1825            std::ostringstream msg;
1826            msg << "Column not found (" << i + 1 << ")";
1827            throw DataFormatError(msg.str().c_str());
1828          }
1829        }
1830        if (line >> std::ws >> c)
1831          throw DataFormatError("Extra character on the end of line");
1832
1833        Edge e;
1834        if (!_use_edges) {
1835
1836          typename NodeIndex::iterator it;
1837
1838          it = _node_index.find(source_token);
1839          if (it == _node_index.end()) {
1840            std::ostringstream msg;
1841            msg << "Item not found: " << source_token;
1842            throw DataFormatError(msg.str().c_str());
1843          }
1844          Node source = it->second;
1845
1846          it = _node_index.find(target_token);
1847          if (it == _node_index.end()) {
1848            std::ostringstream msg;
1849            msg << "Item not found: " << target_token;
1850            throw DataFormatError(msg.str().c_str());
1851          }
1852          Node target = it->second;
1853
1854          e = _graph.addEdge(source, target);
1855          if (label_index != -1)
1856            _edge_index.insert(std::make_pair(tokens[label_index], e));
1857        } else {
1858          if (label_index == -1)
1859            throw DataFormatError("Label map not found in file");
1860          typename std::map<std::string, Edge>::iterator it =
1861            _edge_index.find(tokens[label_index]);
1862          if (it == _edge_index.end()) {
1863            std::ostringstream msg;
1864            msg << "Edge with label not found: " << tokens[label_index];
1865            throw DataFormatError(msg.str().c_str());
1866          }
1867          e = it->second;
1868        }
1869
1870        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1871          _edge_maps[i].second->set(e, tokens[map_index[i]]);
1872        }
1873
1874      }
1875      if (readSuccess()) {
1876        line.putback(c);
1877      }
1878    }
1879
1880    void readAttributes() {
1881
1882      std::set<std::string> read_attr;
1883
1884      char c;
1885      while (readLine() && line >> c && c != '@') {
1886        line.putback(c);
1887
1888        std::string attr, token;
1889        if (!_reader_bits::readToken(line, attr))
1890          throw DataFormatError("Attribute name not found");
1891        if (!_reader_bits::readToken(line, token))
1892          throw DataFormatError("Attribute value not found");
1893        if (line >> c)
1894          throw DataFormatError("Extra character on the end of line");
1895
1896        {
1897          std::set<std::string>::iterator it = read_attr.find(attr);
1898          if (it != read_attr.end()) {
1899            std::ostringstream msg;
1900            msg << "Multiple occurence of attribute " << attr;
1901            throw DataFormatError(msg.str().c_str());
1902          }
1903          read_attr.insert(attr);
1904        }
1905
1906        {
1907          typename Attributes::iterator it = _attributes.lower_bound(attr);
1908          while (it != _attributes.end() && it->first == attr) {
1909            it->second->set(token);
1910            ++it;
1911          }
1912        }
1913
1914      }
1915      if (readSuccess()) {
1916        line.putback(c);
1917      }
1918      for (typename Attributes::iterator it = _attributes.begin();
1919           it != _attributes.end(); ++it) {
1920        if (read_attr.find(it->first) == read_attr.end()) {
1921          std::ostringstream msg;
1922          msg << "Attribute not found in file: " << it->first;
1923          throw DataFormatError(msg.str().c_str());
1924        }
1925      }
1926    }
1927
1928  public:
1929
1930    /// \name Execution of the reader
1931    /// @{
1932
1933    /// \brief Start the batch processing
1934    ///
1935    /// This function starts the batch processing
1936    void run() {
1937
1938      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1939
1940      bool nodes_done = _skip_nodes;
1941      bool edges_done = _skip_edges;
1942      bool attributes_done = false;
1943
1944      line_num = 0;
1945      readLine();
1946      skipSection();
1947
1948      while (readSuccess()) {
1949        try {
1950          char c;
1951          std::string section, caption;
1952          line >> c;
1953          _reader_bits::readToken(line, section);
1954          _reader_bits::readToken(line, caption);
1955
1956          if (line >> c)
1957            throw DataFormatError("Extra character on the end of line");
1958
1959          if (section == "nodes" && !nodes_done) {
1960            if (_nodes_caption.empty() || _nodes_caption == caption) {
1961              readNodes();
1962              nodes_done = true;
1963            }
1964          } else if ((section == "edges" || section == "arcs") &&
1965                     !edges_done) {
1966            if (_edges_caption.empty() || _edges_caption == caption) {
1967              readEdges();
1968              edges_done = true;
1969            }
1970          } else if (section == "attributes" && !attributes_done) {
1971            if (_attributes_caption.empty() || _attributes_caption == caption) {
1972              readAttributes();
1973              attributes_done = true;
1974            }
1975          } else {
1976            readLine();
1977            skipSection();
1978          }
1979        } catch (DataFormatError& error) {
1980          error.line(line_num);
1981          throw;
1982        }
1983      }
1984
1985      if (!nodes_done) {
1986        throw DataFormatError("Section @nodes not found");
1987      }
1988
1989      if (!edges_done) {
1990        throw DataFormatError("Section @edges not found");
1991      }
1992
1993      if (!attributes_done && !_attributes.empty()) {
1994        throw DataFormatError("Section @attributes not found");
1995      }
1996
1997    }
1998
1999    /// @}
2000
2001  };
2002
2003  /// \brief Return a \ref GraphReader class
2004  ///
2005  /// This function just returns a \ref GraphReader class.
2006  /// \relates GraphReader
2007  template <typename Graph>
2008  GraphReader<Graph> graphReader(std::istream& is, Graph& graph) {
2009    GraphReader<Graph> tmp(is, graph);
2010    return tmp;
2011  }
2012
2013  /// \brief Return a \ref GraphReader class
2014  ///
2015  /// This function just returns a \ref GraphReader class.
2016  /// \relates GraphReader
2017  template <typename Graph>
2018  GraphReader<Graph> graphReader(const std::string& fn,
2019                                       Graph& graph) {
2020    GraphReader<Graph> tmp(fn, graph);
2021    return tmp;
2022  }
2023
2024  /// \brief Return a \ref GraphReader class
2025  ///
2026  /// This function just returns a \ref GraphReader class.
2027  /// \relates GraphReader
2028  template <typename Graph>
2029  GraphReader<Graph> graphReader(const char* fn, Graph& graph) {
2030    GraphReader<Graph> tmp(fn, graph);
2031    return tmp;
2032  }
2033
2034  class SectionReader;
2035
2036  SectionReader sectionReader(std::istream& is);
2037  SectionReader sectionReader(const std::string& fn);
2038  SectionReader sectionReader(const char* fn);
2039
2040  /// \ingroup lemon_io
2041  ///
2042  /// \brief Section reader class
2043  ///
2044  /// In the \ref lgf-format "LGF" file extra sections can be placed,
2045  /// which contain any data in arbitrary format. Such sections can be
2046  /// read with this class. A reading rule can be added to the class
2047  /// with two different functions. With the \c sectionLines() function a
2048  /// functor can process the section line-by-line, while with the \c
2049  /// sectionStream() member the section can be read from an input
2050  /// stream.
2051  class SectionReader {
2052  private:
2053
2054    std::istream* _is;
2055    bool local_is;
2056
2057    typedef std::map<std::string, _reader_bits::Section*> Sections;
2058    Sections _sections;
2059
2060    int line_num;
2061    std::istringstream line;
2062
2063  public:
2064
2065    /// \brief Constructor
2066    ///
2067    /// Construct a section reader, which reads from the given input
2068    /// stream.
2069    SectionReader(std::istream& is)
2070      : _is(&is), local_is(false) {}
2071
2072    /// \brief Constructor
2073    ///
2074    /// Construct a section reader, which reads from the given file.
2075    SectionReader(const std::string& fn)
2076      : _is(new std::ifstream(fn.c_str())), local_is(true) {}
2077
2078    /// \brief Constructor
2079    ///
2080    /// Construct a section reader, which reads from the given file.
2081    SectionReader(const char* fn)
2082      : _is(new std::ifstream(fn)), local_is(true) {}
2083
2084    /// \brief Destructor
2085    ~SectionReader() {
2086      for (Sections::iterator it = _sections.begin();
2087           it != _sections.end(); ++it) {
2088        delete it->second;
2089      }
2090
2091      if (local_is) {
2092        delete _is;
2093      }
2094
2095    }
2096
2097  private:
2098
2099    friend SectionReader sectionReader(std::istream& is);
2100    friend SectionReader sectionReader(const std::string& fn);
2101    friend SectionReader sectionReader(const char* fn);
2102
2103    SectionReader(SectionReader& other)
2104      : _is(other._is), local_is(other.local_is) {
2105
2106      other._is = 0;
2107      other.local_is = false;
2108
2109      _sections.swap(other._sections);
2110    }
2111
2112    SectionReader& operator=(const SectionReader&);
2113
2114  public:
2115
2116    /// \name Section readers
2117    /// @{
2118
2119    /// \brief Add a section processor with line oriented reading
2120    ///
2121    /// The first parameter is the type descriptor of the section, the
2122    /// second is a functor, which takes just one \c std::string
2123    /// parameter. At the reading process, each line of the section
2124    /// will be given to the functor object. However, the empty lines
2125    /// and the comment lines are filtered out, and the leading
2126    /// whitespaces are trimmed from each processed string.
2127    ///
2128    /// For example let's see a section, which contain several
2129    /// integers, which should be inserted into a vector.
2130    ///\code
2131    ///  @numbers
2132    ///  12 45 23
2133    ///  4
2134    ///  23 6
2135    ///\endcode
2136    ///
2137    /// The functor is implemented as a struct:
2138    ///\code
2139    ///  struct NumberSection {
2140    ///    std::vector<int>& _data;
2141    ///    NumberSection(std::vector<int>& data) : _data(data) {}
2142    ///    void operator()(const std::string& line) {
2143    ///      std::istringstream ls(line);
2144    ///      int value;
2145    ///      while (ls >> value) _data.push_back(value);
2146    ///    }
2147    ///  };
2148    ///
2149    ///  // ...
2150    ///
2151    ///  reader.sectionLines("numbers", NumberSection(vec));
2152    ///\endcode
2153    template <typename Functor>
2154    SectionReader& sectionLines(const std::string& type, Functor functor) {
2155      LEMON_ASSERT(!type.empty(), "Type is empty.");
2156      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2157                   "Multiple reading of section.");
2158      _sections.insert(std::make_pair(type,
2159        new _reader_bits::LineSection<Functor>(functor)));
2160      return *this;
2161    }
2162
2163
2164    /// \brief Add a section processor with stream oriented reading
2165    ///
2166    /// The first parameter is the type of the section, the second is
2167    /// a functor, which takes an \c std::istream& and an \c int&
2168    /// parameter, the latter regard to the line number of stream. The
2169    /// functor can read the input while the section go on, and the
2170    /// line number should be modified accordingly.
2171    template <typename Functor>
2172    SectionReader& sectionStream(const std::string& type, Functor functor) {
2173      LEMON_ASSERT(!type.empty(), "Type is empty.");
2174      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2175                   "Multiple reading of section.");
2176      _sections.insert(std::make_pair(type,
2177         new _reader_bits::StreamSection<Functor>(functor)));
2178      return *this;
2179    }
2180
2181    /// @}
2182
2183  private:
2184
2185    bool readLine() {
2186      std::string str;
2187      while(++line_num, std::getline(*_is, str)) {
2188        line.clear(); line.str(str);
2189        char c;
2190        if (line >> std::ws >> c && c != '#') {
2191          line.putback(c);
2192          return true;
2193        }
2194      }
2195      return false;
2196    }
2197
2198    bool readSuccess() {
2199      return static_cast<bool>(*_is);
2200    }
2201
2202    void skipSection() {
2203      char c;
2204      while (readSuccess() && line >> c && c != '@') {
2205        readLine();
2206      }
2207      line.putback(c);
2208    }
2209
2210  public:
2211
2212
2213    /// \name Execution of the reader
2214    /// @{
2215
2216    /// \brief Start the batch processing
2217    ///
2218    /// This function starts the batch processing.
2219    void run() {
2220
2221      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
2222
2223      std::set<std::string> extra_sections;
2224
2225      line_num = 0;
2226      readLine();
2227      skipSection();
2228
2229      while (readSuccess()) {
2230        try {
2231          char c;
2232          std::string section, caption;
2233          line >> c;
2234          _reader_bits::readToken(line, section);
2235          _reader_bits::readToken(line, caption);
2236
2237          if (line >> c)
2238            throw DataFormatError("Extra character on the end of line");
2239
2240          if (extra_sections.find(section) != extra_sections.end()) {
2241            std::ostringstream msg;
2242            msg << "Multiple occurence of section " << section;
2243            throw DataFormatError(msg.str().c_str());
2244          }
2245          Sections::iterator it = _sections.find(section);
2246          if (it != _sections.end()) {
2247            extra_sections.insert(section);
2248            it->second->process(*_is, line_num);
2249          }
2250          readLine();
2251          skipSection();
2252        } catch (DataFormatError& error) {
2253          error.line(line_num);
2254          throw;
2255        }
2256      }
2257      for (Sections::iterator it = _sections.begin();
2258           it != _sections.end(); ++it) {
2259        if (extra_sections.find(it->first) == extra_sections.end()) {
2260          std::ostringstream os;
2261          os << "Cannot find section: " << it->first;
2262          throw DataFormatError(os.str().c_str());
2263        }
2264      }
2265    }
2266
2267    /// @}
2268
2269  };
2270
2271  /// \brief Return a \ref SectionReader class
2272  ///
2273  /// This function just returns a \ref SectionReader class.
2274  /// \relates SectionReader
2275  inline SectionReader sectionReader(std::istream& is) {
2276    SectionReader tmp(is);
2277    return tmp;
2278  }
2279
2280  /// \brief Return a \ref SectionReader class
2281  ///
2282  /// This function just returns a \ref SectionReader class.
2283  /// \relates SectionReader
2284  inline SectionReader sectionReader(const std::string& fn) {
2285    SectionReader tmp(fn);
2286    return tmp;
2287  }
2288
2289  /// \brief Return a \ref SectionReader class
2290  ///
2291  /// This function just returns a \ref SectionReader class.
2292  /// \relates SectionReader
2293  inline SectionReader sectionReader(const char* fn) {
2294    SectionReader tmp(fn);
2295    return tmp;
2296  }
2297
2298  /// \ingroup lemon_io
2299  ///
2300  /// \brief Reader for the contents of the \ref lgf-format "LGF" file
2301  ///
2302  /// This class can be used to read the sections, the map names and
2303  /// the attributes from a file. Usually, the Lemon programs know
2304  /// that, which type of graph, which maps and which attributes
2305  /// should be read from a file, but in general tools (like glemon)
2306  /// the contents of an LGF file should be guessed somehow. This class
2307  /// reads the graph and stores the appropriate information for
2308  /// reading the graph.
2309  ///
2310  ///\code
2311  /// LgfContents contents("graph.lgf");
2312  /// contents.run();
2313  ///
2314  /// // Does it contain any node section and arc section?
2315  /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
2316  ///   std::cerr << "Failure, cannot find graph." << std::endl;
2317  ///   return -1;
2318  /// }
2319  /// std::cout << "The name of the default node section: "
2320  ///           << contents.nodeSection(0) << std::endl;
2321  /// std::cout << "The number of the arc maps: "
2322  ///           << contents.arcMaps(0).size() << std::endl;
2323  /// std::cout << "The name of second arc map: "
2324  ///           << contents.arcMaps(0)[1] << std::endl;
2325  ///\endcode
2326  class LgfContents {
2327  private:
2328
2329    std::istream* _is;
2330    bool local_is;
2331
2332    std::vector<std::string> _node_sections;
2333    std::vector<std::string> _edge_sections;
2334    std::vector<std::string> _attribute_sections;
2335    std::vector<std::string> _extra_sections;
2336
2337    std::vector<bool> _arc_sections;
2338
2339    std::vector<std::vector<std::string> > _node_maps;
2340    std::vector<std::vector<std::string> > _edge_maps;
2341
2342    std::vector<std::vector<std::string> > _attributes;
2343
2344
2345    int line_num;
2346    std::istringstream line;
2347
2348  public:
2349
2350    /// \brief Constructor
2351    ///
2352    /// Construct an \e LGF contents reader, which reads from the given
2353    /// input stream.
2354    LgfContents(std::istream& is)
2355      : _is(&is), local_is(false) {}
2356
2357    /// \brief Constructor
2358    ///
2359    /// Construct an \e LGF contents reader, which reads from the given
2360    /// file.
2361    LgfContents(const std::string& fn)
2362      : _is(new std::ifstream(fn.c_str())), local_is(true) {}
2363
2364    /// \brief Constructor
2365    ///
2366    /// Construct an \e LGF contents reader, which reads from the given
2367    /// file.
2368    LgfContents(const char* fn)
2369      : _is(new std::ifstream(fn)), local_is(true) {}
2370
2371    /// \brief Destructor
2372    ~LgfContents() {
2373      if (local_is) delete _is;
2374    }
2375
2376  private:
2377
2378    LgfContents(const LgfContents&);
2379    LgfContents& operator=(const LgfContents&);
2380
2381  public:
2382
2383
2384    /// \name Node sections
2385    /// @{
2386
2387    /// \brief Gives back the number of node sections in the file.
2388    ///
2389    /// Gives back the number of node sections in the file.
2390    int nodeSectionNum() const {
2391      return _node_sections.size();
2392    }
2393
2394    /// \brief Returns the node section name at the given position.
2395    ///
2396    /// Returns the node section name at the given position.
2397    const std::string& nodeSection(int i) const {
2398      return _node_sections[i];
2399    }
2400
2401    /// \brief Gives back the node maps for the given section.
2402    ///
2403    /// Gives back the node maps for the given section.
2404    const std::vector<std::string>& nodeMapNames(int i) const {
2405      return _node_maps[i];
2406    }
2407
2408    /// @}
2409
2410    /// \name Arc/Edge sections
2411    /// @{
2412
2413    /// \brief Gives back the number of arc/edge sections in the file.
2414    ///
2415    /// Gives back the number of arc/edge sections in the file.
2416    /// \note It is synonym of \c edgeSectionNum().
2417    int arcSectionNum() const {
2418      return _edge_sections.size();
2419    }
2420
2421    /// \brief Returns the arc/edge section name at the given position.
2422    ///
2423    /// Returns the arc/edge section name at the given position.
2424    /// \note It is synonym of \c edgeSection().
2425    const std::string& arcSection(int i) const {
2426      return _edge_sections[i];
2427    }
2428
2429    /// \brief Gives back the arc/edge maps for the given section.
2430    ///
2431    /// Gives back the arc/edge maps for the given section.
2432    /// \note It is synonym of \c edgeMapNames().
2433    const std::vector<std::string>& arcMapNames(int i) const {
2434      return _edge_maps[i];
2435    }
2436
2437    /// @}
2438
2439    /// \name Synonyms
2440    /// @{
2441
2442    /// \brief Gives back the number of arc/edge sections in the file.
2443    ///
2444    /// Gives back the number of arc/edge sections in the file.
2445    /// \note It is synonym of \c arcSectionNum().
2446    int edgeSectionNum() const {
2447      return _edge_sections.size();
2448    }
2449
2450    /// \brief Returns the section name at the given position.
2451    ///
2452    /// Returns the section name at the given position.
2453    /// \note It is synonym of \c arcSection().
2454    const std::string& edgeSection(int i) const {
2455      return _edge_sections[i];
2456    }
2457
2458    /// \brief Gives back the edge maps for the given section.
2459    ///
2460    /// Gives back the edge maps for the given section.
2461    /// \note It is synonym of \c arcMapNames().
2462    const std::vector<std::string>& edgeMapNames(int i) const {
2463      return _edge_maps[i];
2464    }
2465
2466    /// @}
2467
2468    /// \name Attribute sections
2469    /// @{
2470
2471    /// \brief Gives back the number of attribute sections in the file.
2472    ///
2473    /// Gives back the number of attribute sections in the file.
2474    int attributeSectionNum() const {
2475      return _attribute_sections.size();
2476    }
2477
2478    /// \brief Returns the attribute section name at the given position.
2479    ///
2480    /// Returns the attribute section name at the given position.
2481    const std::string& attributeSectionNames(int i) const {
2482      return _attribute_sections[i];
2483    }
2484
2485    /// \brief Gives back the attributes for the given section.
2486    ///
2487    /// Gives back the attributes for the given section.
2488    const std::vector<std::string>& attributes(int i) const {
2489      return _attributes[i];
2490    }
2491
2492    /// @}
2493
2494    /// \name Extra sections
2495    /// @{
2496
2497    /// \brief Gives back the number of extra sections in the file.
2498    ///
2499    /// Gives back the number of extra sections in the file.
2500    int extraSectionNum() const {
2501      return _extra_sections.size();
2502    }
2503
2504    /// \brief Returns the extra section type at the given position.
2505    ///
2506    /// Returns the section type at the given position.
2507    const std::string& extraSection(int i) const {
2508      return _extra_sections[i];
2509    }
2510
2511    /// @}
2512
2513  private:
2514
2515    bool readLine() {
2516      std::string str;
2517      while(++line_num, std::getline(*_is, str)) {
2518        line.clear(); line.str(str);
2519        char c;
2520        if (line >> std::ws >> c && c != '#') {
2521          line.putback(c);
2522          return true;
2523        }
2524      }
2525      return false;
2526    }
2527
2528    bool readSuccess() {
2529      return static_cast<bool>(*_is);
2530    }
2531
2532    void skipSection() {
2533      char c;
2534      while (readSuccess() && line >> c && c != '@') {
2535        readLine();
2536      }
2537      line.putback(c);
2538    }
2539
2540    void readMaps(std::vector<std::string>& maps) {
2541      char c;
2542      if (!readLine() || !(line >> c) || c == '@') {
2543        if (readSuccess() && line) line.putback(c);
2544        return;
2545      }
2546      line.putback(c);
2547      std::string map;
2548      while (_reader_bits::readToken(line, map)) {
2549        maps.push_back(map);
2550      }
2551    }
2552
2553    void readAttributes(std::vector<std::string>& attrs) {
2554      readLine();
2555      char c;
2556      while (readSuccess() && line >> c && c != '@') {
2557        line.putback(c);
2558        std::string attr;
2559        _reader_bits::readToken(line, attr);
2560        attrs.push_back(attr);
2561        readLine();
2562      }
2563      line.putback(c);
2564    }
2565
2566  public:
2567
2568    /// \name Execution of the contents reader
2569    /// @{
2570
2571    /// \brief Starts the reading
2572    ///
2573    /// This function starts the reading.
2574    void run() {
2575
2576      readLine();
2577      skipSection();
2578
2579      while (readSuccess()) {
2580
2581        char c;
2582        line >> c;
2583
2584        std::string section, caption;
2585        _reader_bits::readToken(line, section);
2586        _reader_bits::readToken(line, caption);
2587
2588        if (section == "nodes") {
2589          _node_sections.push_back(caption);
2590          _node_maps.push_back(std::vector<std::string>());
2591          readMaps(_node_maps.back());
2592          readLine(); skipSection();
2593        } else if (section == "arcs" || section == "edges") {
2594          _edge_sections.push_back(caption);
2595          _arc_sections.push_back(section == "arcs");
2596          _edge_maps.push_back(std::vector<std::string>());
2597          readMaps(_edge_maps.back());
2598          readLine(); skipSection();
2599        } else if (section == "attributes") {
2600          _attribute_sections.push_back(caption);
2601          _attributes.push_back(std::vector<std::string>());
2602          readAttributes(_attributes.back());
2603        } else {
2604          _extra_sections.push_back(section);
2605          readLine(); skipSection();
2606        }
2607      }
2608    }
2609
2610    /// @}
2611
2612  };
2613}
2614
2615#endif
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