COIN-OR::LEMON - Graph Library

source: lemon-main/lemon/lgf_reader.h @ 305:069f27927ba9

Last change on this file since 305:069f27927ba9 was 295:7c796c1cf1b0, checked in by Balazs Dezso <deba@…>, 16 years ago

Fix memory leak hazard

If the constructor throws an exception, it should deallocate each
dynamically allocated memory.

File size: 78.4 KB
Line 
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/core.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        if (!(is >> value)) {
52          throw FormatError("Cannot read token");
53        }
54
55        char c;
56        if (is >> std::ws >> c) {
57          throw FormatError("Remaining characters in token");
58        }
59        return value;
60      }
61    };
62
63    template <>
64    struct DefaultConverter<std::string> {
65      std::string operator()(const std::string& str) {
66        return str;
67      }
68    };
69
70    template <typename _Item>
71    class MapStorageBase {
72    public:
73      typedef _Item Item;
74
75    public:
76      MapStorageBase() {}
77      virtual ~MapStorageBase() {}
78
79      virtual void set(const Item& item, const std::string& value) = 0;
80
81    };
82
83    template <typename _Item, typename _Map,
84              typename _Converter = DefaultConverter<typename _Map::Value> >
85    class MapStorage : public MapStorageBase<_Item> {
86    public:
87      typedef _Map Map;
88      typedef _Converter Converter;
89      typedef _Item Item;
90
91    private:
92      Map& _map;
93      Converter _converter;
94
95    public:
96      MapStorage(Map& map, const Converter& converter = Converter())
97        : _map(map), _converter(converter) {}
98      virtual ~MapStorage() {}
99
100      virtual void set(const Item& item ,const std::string& value) {
101        _map.set(item, _converter(value));
102      }
103    };
104
105    template <typename _Graph, bool _dir, typename _Map,
106              typename _Converter = DefaultConverter<typename _Map::Value> >
107    class GraphArcMapStorage : public MapStorageBase<typename _Graph::Edge> {
108    public:
109      typedef _Map Map;
110      typedef _Converter Converter;
111      typedef _Graph Graph;
112      typedef typename Graph::Edge Item;
113      static const bool dir = _dir;
114
115    private:
116      const Graph& _graph;
117      Map& _map;
118      Converter _converter;
119
120    public:
121      GraphArcMapStorage(const Graph& graph, Map& map,
122                         const Converter& converter = Converter())
123        : _graph(graph), _map(map), _converter(converter) {}
124      virtual ~GraphArcMapStorage() {}
125
126      virtual void set(const Item& item ,const std::string& value) {
127        _map.set(_graph.direct(item, dir), _converter(value));
128      }
129    };
130
131    class ValueStorageBase {
132    public:
133      ValueStorageBase() {}
134      virtual ~ValueStorageBase() {}
135
136      virtual void set(const std::string&) = 0;
137    };
138
139    template <typename _Value, typename _Converter = DefaultConverter<_Value> >
140    class ValueStorage : public ValueStorageBase {
141    public:
142      typedef _Value Value;
143      typedef _Converter Converter;
144
145    private:
146      Value& _value;
147      Converter _converter;
148
149    public:
150      ValueStorage(Value& value, const Converter& converter = Converter())
151        : _value(value), _converter(converter) {}
152
153      virtual void set(const std::string& value) {
154        _value = _converter(value);
155      }
156    };
157
158    template <typename Value>
159    struct MapLookUpConverter {
160      const std::map<std::string, Value>& _map;
161
162      MapLookUpConverter(const std::map<std::string, Value>& map)
163        : _map(map) {}
164
165      Value operator()(const std::string& str) {
166        typename std::map<std::string, Value>::const_iterator it =
167          _map.find(str);
168        if (it == _map.end()) {
169          std::ostringstream msg;
170          msg << "Item not found: " << str;
171          throw FormatError(msg.str());
172        }
173        return it->second;
174      }
175    };
176
177    template <typename Graph>
178    struct GraphArcLookUpConverter {
179      const Graph& _graph;
180      const std::map<std::string, typename Graph::Edge>& _map;
181
182      GraphArcLookUpConverter(const Graph& graph,
183                              const std::map<std::string,
184                                             typename Graph::Edge>& map)
185        : _graph(graph), _map(map) {}
186
187      typename Graph::Arc operator()(const std::string& str) {
188        if (str.empty() || (str[0] != '+' && str[0] != '-')) {
189          throw FormatError("Item must start with '+' or '-'");
190        }
191        typename std::map<std::string, typename Graph::Edge>
192          ::const_iterator it = _map.find(str.substr(1));
193        if (it == _map.end()) {
194          throw FormatError("Item not found");
195        }
196        return _graph.direct(it->second, str[0] == '+');
197      }
198    };
199
200    inline bool isWhiteSpace(char c) {
201      return c == ' ' || c == '\t' || c == '\v' ||
202        c == '\n' || c == '\r' || c == '\f';
203    }
204
205    inline bool isOct(char c) {
206      return '0' <= c && c <='7';
207    }
208
209    inline int valueOct(char c) {
210      LEMON_ASSERT(isOct(c), "The character is not octal.");
211      return c - '0';
212    }
213
214    inline bool isHex(char c) {
215      return ('0' <= c && c <= '9') ||
216        ('a' <= c && c <= 'z') ||
217        ('A' <= c && c <= 'Z');
218    }
219
220    inline int valueHex(char c) {
221      LEMON_ASSERT(isHex(c), "The character is not hexadecimal.");
222      if ('0' <= c && c <= '9') return c - '0';
223      if ('a' <= c && c <= 'z') return c - 'a' + 10;
224      return c - 'A' + 10;
225    }
226
227    inline bool isIdentifierFirstChar(char c) {
228      return ('a' <= c && c <= 'z') ||
229        ('A' <= c && c <= 'Z') || c == '_';
230    }
231
232    inline bool isIdentifierChar(char c) {
233      return isIdentifierFirstChar(c) ||
234        ('0' <= c && c <= '9');
235    }
236
237    inline char readEscape(std::istream& is) {
238      char c;
239      if (!is.get(c))
240        throw FormatError("Escape format error");
241
242      switch (c) {
243      case '\\':
244        return '\\';
245      case '\"':
246        return '\"';
247      case '\'':
248        return '\'';
249      case '\?':
250        return '\?';
251      case 'a':
252        return '\a';
253      case 'b':
254        return '\b';
255      case 'f':
256        return '\f';
257      case 'n':
258        return '\n';
259      case 'r':
260        return '\r';
261      case 't':
262        return '\t';
263      case 'v':
264        return '\v';
265      case 'x':
266        {
267          int code;
268          if (!is.get(c) || !isHex(c))
269            throw FormatError("Escape format error");
270          else if (code = valueHex(c), !is.get(c) || !isHex(c)) is.putback(c);
271          else code = code * 16 + valueHex(c);
272          return code;
273        }
274      default:
275        {
276          int code;
277          if (!isOct(c))
278            throw FormatError("Escape format error");
279          else if (code = valueOct(c), !is.get(c) || !isOct(c))
280            is.putback(c);
281          else if (code = code * 8 + valueOct(c), !is.get(c) || !isOct(c))
282            is.putback(c);
283          else code = code * 8 + valueOct(c);
284          return code;
285        }
286      }
287    }
288
289    inline std::istream& readToken(std::istream& is, std::string& str) {
290      std::ostringstream os;
291
292      char c;
293      is >> std::ws;
294
295      if (!is.get(c))
296        return is;
297
298      if (c == '\"') {
299        while (is.get(c) && c != '\"') {
300          if (c == '\\')
301            c = readEscape(is);
302          os << c;
303        }
304        if (!is)
305          throw FormatError("Quoted format error");
306      } else {
307        is.putback(c);
308        while (is.get(c) && !isWhiteSpace(c)) {
309          if (c == '\\')
310            c = readEscape(is);
311          os << c;
312        }
313        if (!is) {
314          is.clear();
315        } else {
316          is.putback(c);
317        }
318      }
319      str = os.str();
320      return is;
321    }
322
323    class Section {
324    public:
325      virtual ~Section() {}
326      virtual void process(std::istream& is, int& line_num) = 0;
327    };
328
329    template <typename Functor>
330    class LineSection : public Section {
331    private:
332
333      Functor _functor;
334
335    public:
336
337      LineSection(const Functor& functor) : _functor(functor) {}
338      virtual ~LineSection() {}
339
340      virtual void process(std::istream& is, int& line_num) {
341        char c;
342        std::string line;
343        while (is.get(c) && c != '@') {
344          if (c == '\n') {
345            ++line_num;
346          } else if (c == '#') {
347            getline(is, line);
348            ++line_num;
349          } else if (!isWhiteSpace(c)) {
350            is.putback(c);
351            getline(is, line);
352            _functor(line);
353            ++line_num;
354          }
355        }
356        if (is) is.putback(c);
357        else if (is.eof()) is.clear();
358      }
359    };
360
361    template <typename Functor>
362    class StreamSection : public Section {
363    private:
364
365      Functor _functor;
366
367    public:
368
369      StreamSection(const Functor& functor) : _functor(functor) {}
370      virtual ~StreamSection() {}
371
372      virtual void process(std::istream& is, int& line_num) {
373        _functor(is, line_num);
374        char c;
375        std::string line;
376        while (is.get(c) && c != '@') {
377          if (c == '\n') {
378            ++line_num;
379          } else if (!isWhiteSpace(c)) {
380            getline(is, line);
381            ++line_num;
382          }
383        }
384        if (is) is.putback(c);
385        else if (is.eof()) is.clear();
386      }
387    };
388
389  }
390
391  template <typename Digraph>
392  class DigraphReader;
393
394  template <typename Digraph>
395  DigraphReader<Digraph> digraphReader(Digraph& digraph,
396                                       std::istream& is = std::cin);
397
398  template <typename Digraph>
399  DigraphReader<Digraph> digraphReader(Digraph& digraph, const std::string& fn);
400
401  template <typename Digraph>
402  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char *fn);
403
404  /// \ingroup lemon_io
405  ///
406  /// \brief \ref lgf-format "LGF" reader for directed graphs
407  ///
408  /// This utility reads an \ref lgf-format "LGF" file.
409  ///
410  /// The reading method does a batch processing. The user creates a
411  /// reader object, then various reading rules can be added to the
412  /// reader, and eventually the reading is executed with the \c run()
413  /// member function. A map reading rule can be added to the reader
414  /// with the \c nodeMap() or \c arcMap() members. An optional
415  /// converter parameter can also be added as a standard functor
416  /// converting from \c std::string to the value type of the map. If it
417  /// is set, it will determine how the tokens in the file should be
418  /// converted to the value type of the map. If the functor is not set,
419  /// then a default conversion will be used. One map can be read into
420  /// multiple map objects at the same time. The \c attribute(), \c
421  /// node() and \c arc() functions are used to add attribute reading
422  /// rules.
423  ///
424  ///\code
425  /// DigraphReader<Digraph>(digraph, std::cin).
426  ///   nodeMap("coordinates", coord_map).
427  ///   arcMap("capacity", cap_map).
428  ///   node("source", src).
429  ///   node("target", trg).
430  ///   attribute("caption", caption).
431  ///   run();
432  ///\endcode
433  ///
434  /// By default the reader uses the first section in the file of the
435  /// proper type. If a section has an optional name, then it can be
436  /// selected for reading by giving an optional name parameter to the
437  /// \c nodes(), \c arcs() or \c attributes() functions.
438  ///
439  /// The \c useNodes() and \c useArcs() functions are used to tell the reader
440  /// that the nodes or arcs should not be constructed (added to the
441  /// graph) during the reading, but instead the label map of the items
442  /// are given as a parameter of these functions. An
443  /// application of these functions is multipass reading, which is
444  /// important if two \c \@arcs sections must be read from the
445  /// file. In this case the first phase would read the node set and one
446  /// of the arc sets, while the second phase would read the second arc
447  /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
448  /// The previously read label node map should be passed to the \c
449  /// useNodes() functions. Another application of multipass reading when
450  /// paths are given as a node map or an arc map.
451  /// It is impossible to read this in
452  /// a single pass, because the arcs are not constructed when the node
453  /// maps are read.
454  template <typename _Digraph>
455  class DigraphReader {
456  public:
457
458    typedef _Digraph Digraph;
459    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
460
461  private:
462
463
464    std::istream* _is;
465    bool local_is;
466    std::string _filename;
467
468    Digraph& _digraph;
469
470    std::string _nodes_caption;
471    std::string _arcs_caption;
472    std::string _attributes_caption;
473
474    typedef std::map<std::string, Node> NodeIndex;
475    NodeIndex _node_index;
476    typedef std::map<std::string, Arc> ArcIndex;
477    ArcIndex _arc_index;
478
479    typedef std::vector<std::pair<std::string,
480      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
481    NodeMaps _node_maps;
482
483    typedef std::vector<std::pair<std::string,
484      _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
485    ArcMaps _arc_maps;
486
487    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
488      Attributes;
489    Attributes _attributes;
490
491    bool _use_nodes;
492    bool _use_arcs;
493
494    bool _skip_nodes;
495    bool _skip_arcs;
496
497    int line_num;
498    std::istringstream line;
499
500  public:
501
502    /// \brief Constructor
503    ///
504    /// Construct a directed graph reader, which reads from the given
505    /// input stream.
506    DigraphReader(Digraph& digraph, std::istream& is = std::cin)
507      : _is(&is), local_is(false), _digraph(digraph),
508        _use_nodes(false), _use_arcs(false),
509        _skip_nodes(false), _skip_arcs(false) {}
510
511    /// \brief Constructor
512    ///
513    /// Construct a directed graph reader, which reads from the given
514    /// file.
515    DigraphReader(Digraph& digraph, const std::string& fn)
516      : _is(new std::ifstream(fn.c_str())), local_is(true),
517        _filename(fn), _digraph(digraph),
518        _use_nodes(false), _use_arcs(false),
519        _skip_nodes(false), _skip_arcs(false) {
520      if (!(*_is)) {
521        delete _is;
522        throw IoError("Cannot open file", fn);
523      }
524    }
525
526    /// \brief Constructor
527    ///
528    /// Construct a directed graph reader, which reads from the given
529    /// file.
530    DigraphReader(Digraph& digraph, const char* fn)
531      : _is(new std::ifstream(fn)), local_is(true),
532        _filename(fn), _digraph(digraph),
533        _use_nodes(false), _use_arcs(false),
534        _skip_nodes(false), _skip_arcs(false) {
535      if (!(*_is)) {
536        delete _is;
537        throw IoError("Cannot open file", fn);
538      }
539    }
540
541    /// \brief Destructor
542    ~DigraphReader() {
543      for (typename NodeMaps::iterator it = _node_maps.begin();
544           it != _node_maps.end(); ++it) {
545        delete it->second;
546      }
547
548      for (typename ArcMaps::iterator it = _arc_maps.begin();
549           it != _arc_maps.end(); ++it) {
550        delete it->second;
551      }
552
553      for (typename Attributes::iterator it = _attributes.begin();
554           it != _attributes.end(); ++it) {
555        delete it->second;
556      }
557
558      if (local_is) {
559        delete _is;
560      }
561
562    }
563
564  private:
565
566    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
567                                                  std::istream& is);
568    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
569                                                  const std::string& fn);
570    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
571                                                  const char *fn);
572
573    DigraphReader(DigraphReader& other)
574      : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
575        _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
576        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
577
578      other._is = 0;
579      other.local_is = false;
580
581      _node_index.swap(other._node_index);
582      _arc_index.swap(other._arc_index);
583
584      _node_maps.swap(other._node_maps);
585      _arc_maps.swap(other._arc_maps);
586      _attributes.swap(other._attributes);
587
588      _nodes_caption = other._nodes_caption;
589      _arcs_caption = other._arcs_caption;
590      _attributes_caption = other._attributes_caption;
591
592    }
593
594    DigraphReader& operator=(const DigraphReader&);
595
596  public:
597
598    /// \name Reading rules
599    /// @{
600
601    /// \brief Node map reading rule
602    ///
603    /// Add a node map reading rule to the reader.
604    template <typename Map>
605    DigraphReader& nodeMap(const std::string& caption, Map& map) {
606      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
607      _reader_bits::MapStorageBase<Node>* storage =
608        new _reader_bits::MapStorage<Node, Map>(map);
609      _node_maps.push_back(std::make_pair(caption, storage));
610      return *this;
611    }
612
613    /// \brief Node map reading rule
614    ///
615    /// Add a node map reading rule with specialized converter to the
616    /// reader.
617    template <typename Map, typename Converter>
618    DigraphReader& nodeMap(const std::string& caption, Map& map,
619                           const Converter& converter = Converter()) {
620      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
621      _reader_bits::MapStorageBase<Node>* storage =
622        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
623      _node_maps.push_back(std::make_pair(caption, storage));
624      return *this;
625    }
626
627    /// \brief Arc map reading rule
628    ///
629    /// Add an arc map reading rule to the reader.
630    template <typename Map>
631    DigraphReader& arcMap(const std::string& caption, Map& map) {
632      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
633      _reader_bits::MapStorageBase<Arc>* storage =
634        new _reader_bits::MapStorage<Arc, Map>(map);
635      _arc_maps.push_back(std::make_pair(caption, storage));
636      return *this;
637    }
638
639    /// \brief Arc map reading rule
640    ///
641    /// Add an arc map reading rule with specialized converter to the
642    /// reader.
643    template <typename Map, typename Converter>
644    DigraphReader& arcMap(const std::string& caption, Map& map,
645                          const Converter& converter = Converter()) {
646      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
647      _reader_bits::MapStorageBase<Arc>* storage =
648        new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
649      _arc_maps.push_back(std::make_pair(caption, storage));
650      return *this;
651    }
652
653    /// \brief Attribute reading rule
654    ///
655    /// Add an attribute reading rule to the reader.
656    template <typename Value>
657    DigraphReader& attribute(const std::string& caption, Value& value) {
658      _reader_bits::ValueStorageBase* storage =
659        new _reader_bits::ValueStorage<Value>(value);
660      _attributes.insert(std::make_pair(caption, storage));
661      return *this;
662    }
663
664    /// \brief Attribute reading rule
665    ///
666    /// Add an attribute reading rule with specialized converter to the
667    /// reader.
668    template <typename Value, typename Converter>
669    DigraphReader& attribute(const std::string& caption, Value& value,
670                             const Converter& converter = Converter()) {
671      _reader_bits::ValueStorageBase* storage =
672        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
673      _attributes.insert(std::make_pair(caption, storage));
674      return *this;
675    }
676
677    /// \brief Node reading rule
678    ///
679    /// Add a node reading rule to reader.
680    DigraphReader& node(const std::string& caption, Node& node) {
681      typedef _reader_bits::MapLookUpConverter<Node> Converter;
682      Converter converter(_node_index);
683      _reader_bits::ValueStorageBase* storage =
684        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
685      _attributes.insert(std::make_pair(caption, storage));
686      return *this;
687    }
688
689    /// \brief Arc reading rule
690    ///
691    /// Add an arc reading rule to reader.
692    DigraphReader& arc(const std::string& caption, Arc& arc) {
693      typedef _reader_bits::MapLookUpConverter<Arc> Converter;
694      Converter converter(_arc_index);
695      _reader_bits::ValueStorageBase* storage =
696        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
697      _attributes.insert(std::make_pair(caption, storage));
698      return *this;
699    }
700
701    /// @}
702
703    /// \name Select section by name
704    /// @{
705
706    /// \brief Set \c \@nodes section to be read
707    ///
708    /// Set \c \@nodes section to be read
709    DigraphReader& nodes(const std::string& caption) {
710      _nodes_caption = caption;
711      return *this;
712    }
713
714    /// \brief Set \c \@arcs section to be read
715    ///
716    /// Set \c \@arcs section to be read
717    DigraphReader& arcs(const std::string& caption) {
718      _arcs_caption = caption;
719      return *this;
720    }
721
722    /// \brief Set \c \@attributes section to be read
723    ///
724    /// Set \c \@attributes section to be read
725    DigraphReader& attributes(const std::string& caption) {
726      _attributes_caption = caption;
727      return *this;
728    }
729
730    /// @}
731
732    /// \name Using previously constructed node or arc set
733    /// @{
734
735    /// \brief Use previously constructed node set
736    ///
737    /// Use previously constructed node set, and specify the node
738    /// label map.
739    template <typename Map>
740    DigraphReader& useNodes(const Map& map) {
741      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
742      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
743      _use_nodes = true;
744      _writer_bits::DefaultConverter<typename Map::Value> converter;
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 node set
752    ///
753    /// Use previously constructed node set, and specify the node
754    /// label map and a functor which converts the label map values to
755    /// \c std::string.
756    template <typename Map, typename Converter>
757    DigraphReader& useNodes(const Map& map,
758                            const Converter& converter = Converter()) {
759      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
760      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
761      _use_nodes = true;
762      for (NodeIt n(_digraph); n != INVALID; ++n) {
763        _node_index.insert(std::make_pair(converter(map[n]), n));
764      }
765      return *this;
766    }
767
768    /// \brief Use previously constructed arc set
769    ///
770    /// Use previously constructed arc set, and specify the arc
771    /// label map.
772    template <typename Map>
773    DigraphReader& useArcs(const Map& map) {
774      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
775      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
776      _use_arcs = true;
777      _writer_bits::DefaultConverter<typename Map::Value> converter;
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 Use previously constructed arc set
785    ///
786    /// Use previously constructed arc set, and specify the arc
787    /// label map and a functor which converts the label map values to
788    /// \c std::string.
789    template <typename Map, typename Converter>
790    DigraphReader& useArcs(const Map& map,
791                           const Converter& converter = Converter()) {
792      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
793      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
794      _use_arcs = true;
795      for (ArcIt a(_digraph); a != INVALID; ++a) {
796        _arc_index.insert(std::make_pair(converter(map[a]), a));
797      }
798      return *this;
799    }
800
801    /// \brief Skips the reading of node section
802    ///
803    /// Omit the reading of the node section. This implies that each node
804    /// map reading rule will be abandoned, and the nodes of the graph
805    /// will not be constructed, which usually cause that the arc set
806    /// could not be read due to lack of node name resolving.
807    /// Therefore \c skipArcs() function should also be used, or
808    /// \c useNodes() should be used to specify the label of the nodes.
809    DigraphReader& skipNodes() {
810      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
811      _skip_nodes = true;
812      return *this;
813    }
814
815    /// \brief Skips the reading of arc section
816    ///
817    /// Omit the reading of the arc section. This implies that each arc
818    /// map reading rule will be abandoned, and the arcs of the graph
819    /// will not be constructed.
820    DigraphReader& skipArcs() {
821      LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
822      _skip_arcs = true;
823      return *this;
824    }
825
826    /// @}
827
828  private:
829
830    bool readLine() {
831      std::string str;
832      while(++line_num, std::getline(*_is, str)) {
833        line.clear(); line.str(str);
834        char c;
835        if (line >> std::ws >> c && c != '#') {
836          line.putback(c);
837          return true;
838        }
839      }
840      return false;
841    }
842
843    bool readSuccess() {
844      return static_cast<bool>(*_is);
845    }
846
847    void skipSection() {
848      char c;
849      while (readSuccess() && line >> c && c != '@') {
850        readLine();
851      }
852      line.putback(c);
853    }
854
855    void readNodes() {
856
857      std::vector<int> map_index(_node_maps.size());
858      int map_num, label_index;
859
860      char c;
861      if (!readLine() || !(line >> c) || c == '@') {
862        if (readSuccess() && line) line.putback(c);
863        if (!_node_maps.empty())
864          throw FormatError("Cannot find map names");
865        return;
866      }
867      line.putback(c);
868
869      {
870        std::map<std::string, int> maps;
871
872        std::string map;
873        int index = 0;
874        while (_reader_bits::readToken(line, map)) {
875          if (maps.find(map) != maps.end()) {
876            std::ostringstream msg;
877            msg << "Multiple occurence of node map: " << map;
878            throw FormatError(msg.str());
879          }
880          maps.insert(std::make_pair(map, index));
881          ++index;
882        }
883
884        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
885          std::map<std::string, int>::iterator jt =
886            maps.find(_node_maps[i].first);
887          if (jt == maps.end()) {
888            std::ostringstream msg;
889            msg << "Map not found: " << _node_maps[i].first;
890            throw FormatError(msg.str());
891          }
892          map_index[i] = jt->second;
893        }
894
895        {
896          std::map<std::string, int>::iterator jt = maps.find("label");
897          if (jt != maps.end()) {
898            label_index = jt->second;
899          } else {
900            label_index = -1;
901          }
902        }
903        map_num = maps.size();
904      }
905
906      while (readLine() && line >> c && c != '@') {
907        line.putback(c);
908
909        std::vector<std::string> tokens(map_num);
910        for (int i = 0; i < map_num; ++i) {
911          if (!_reader_bits::readToken(line, tokens[i])) {
912            std::ostringstream msg;
913            msg << "Column not found (" << i + 1 << ")";
914            throw FormatError(msg.str());
915          }
916        }
917        if (line >> std::ws >> c)
918          throw FormatError("Extra character at the end of line");
919
920        Node n;
921        if (!_use_nodes) {
922          n = _digraph.addNode();
923          if (label_index != -1)
924            _node_index.insert(std::make_pair(tokens[label_index], n));
925        } else {
926          if (label_index == -1)
927            throw FormatError("Label map not found");
928          typename std::map<std::string, Node>::iterator it =
929            _node_index.find(tokens[label_index]);
930          if (it == _node_index.end()) {
931            std::ostringstream msg;
932            msg << "Node with label not found: " << tokens[label_index];
933            throw FormatError(msg.str());
934          }
935          n = it->second;
936        }
937
938        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
939          _node_maps[i].second->set(n, tokens[map_index[i]]);
940        }
941
942      }
943      if (readSuccess()) {
944        line.putback(c);
945      }
946    }
947
948    void readArcs() {
949
950      std::vector<int> map_index(_arc_maps.size());
951      int map_num, label_index;
952
953      char c;
954      if (!readLine() || !(line >> c) || c == '@') {
955        if (readSuccess() && line) line.putback(c);
956        if (!_arc_maps.empty())
957          throw FormatError("Cannot find map names");
958        return;
959      }
960      line.putback(c);
961
962      {
963        std::map<std::string, int> maps;
964
965        std::string map;
966        int index = 0;
967        while (_reader_bits::readToken(line, map)) {
968          if (maps.find(map) != maps.end()) {
969            std::ostringstream msg;
970            msg << "Multiple occurence of arc map: " << map;
971            throw FormatError(msg.str());
972          }
973          maps.insert(std::make_pair(map, index));
974          ++index;
975        }
976
977        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
978          std::map<std::string, int>::iterator jt =
979            maps.find(_arc_maps[i].first);
980          if (jt == maps.end()) {
981            std::ostringstream msg;
982            msg << "Map not found: " << _arc_maps[i].first;
983            throw FormatError(msg.str());
984          }
985          map_index[i] = jt->second;
986        }
987
988        {
989          std::map<std::string, int>::iterator jt = maps.find("label");
990          if (jt != maps.end()) {
991            label_index = jt->second;
992          } else {
993            label_index = -1;
994          }
995        }
996        map_num = maps.size();
997      }
998
999      while (readLine() && line >> c && c != '@') {
1000        line.putback(c);
1001
1002        std::string source_token;
1003        std::string target_token;
1004
1005        if (!_reader_bits::readToken(line, source_token))
1006          throw FormatError("Source not found");
1007
1008        if (!_reader_bits::readToken(line, target_token))
1009          throw FormatError("Target not found");
1010
1011        std::vector<std::string> tokens(map_num);
1012        for (int i = 0; i < map_num; ++i) {
1013          if (!_reader_bits::readToken(line, tokens[i])) {
1014            std::ostringstream msg;
1015            msg << "Column not found (" << i + 1 << ")";
1016            throw FormatError(msg.str());
1017          }
1018        }
1019        if (line >> std::ws >> c)
1020          throw FormatError("Extra character at the end of line");
1021
1022        Arc a;
1023        if (!_use_arcs) {
1024
1025          typename NodeIndex::iterator it;
1026
1027          it = _node_index.find(source_token);
1028          if (it == _node_index.end()) {
1029            std::ostringstream msg;
1030            msg << "Item not found: " << source_token;
1031            throw FormatError(msg.str());
1032          }
1033          Node source = it->second;
1034
1035          it = _node_index.find(target_token);
1036          if (it == _node_index.end()) {
1037            std::ostringstream msg;
1038            msg << "Item not found: " << target_token;
1039            throw FormatError(msg.str());
1040          }
1041          Node target = it->second;
1042
1043          a = _digraph.addArc(source, target);
1044          if (label_index != -1)
1045            _arc_index.insert(std::make_pair(tokens[label_index], a));
1046        } else {
1047          if (label_index == -1)
1048            throw FormatError("Label map not found");
1049          typename std::map<std::string, Arc>::iterator it =
1050            _arc_index.find(tokens[label_index]);
1051          if (it == _arc_index.end()) {
1052            std::ostringstream msg;
1053            msg << "Arc with label not found: " << tokens[label_index];
1054            throw FormatError(msg.str());
1055          }
1056          a = it->second;
1057        }
1058
1059        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
1060          _arc_maps[i].second->set(a, tokens[map_index[i]]);
1061        }
1062
1063      }
1064      if (readSuccess()) {
1065        line.putback(c);
1066      }
1067    }
1068
1069    void readAttributes() {
1070
1071      std::set<std::string> read_attr;
1072
1073      char c;
1074      while (readLine() && line >> c && c != '@') {
1075        line.putback(c);
1076
1077        std::string attr, token;
1078        if (!_reader_bits::readToken(line, attr))
1079          throw FormatError("Attribute name not found");
1080        if (!_reader_bits::readToken(line, token))
1081          throw FormatError("Attribute value not found");
1082        if (line >> c)
1083          throw FormatError("Extra character at the end of line");
1084
1085        {
1086          std::set<std::string>::iterator it = read_attr.find(attr);
1087          if (it != read_attr.end()) {
1088            std::ostringstream msg;
1089            msg << "Multiple occurence of attribute: " << attr;
1090            throw FormatError(msg.str());
1091          }
1092          read_attr.insert(attr);
1093        }
1094
1095        {
1096          typename Attributes::iterator it = _attributes.lower_bound(attr);
1097          while (it != _attributes.end() && it->first == attr) {
1098            it->second->set(token);
1099            ++it;
1100          }
1101        }
1102
1103      }
1104      if (readSuccess()) {
1105        line.putback(c);
1106      }
1107      for (typename Attributes::iterator it = _attributes.begin();
1108           it != _attributes.end(); ++it) {
1109        if (read_attr.find(it->first) == read_attr.end()) {
1110          std::ostringstream msg;
1111          msg << "Attribute not found: " << it->first;
1112          throw FormatError(msg.str());
1113        }
1114      }
1115    }
1116
1117  public:
1118
1119    /// \name Execution of the reader
1120    /// @{
1121
1122    /// \brief Start the batch processing
1123    ///
1124    /// This function starts the batch processing
1125    void run() {
1126      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1127
1128      bool nodes_done = _skip_nodes;
1129      bool arcs_done = _skip_arcs;
1130      bool attributes_done = false;
1131
1132      line_num = 0;
1133      readLine();
1134      skipSection();
1135
1136      while (readSuccess()) {
1137        try {
1138          char c;
1139          std::string section, caption;
1140          line >> c;
1141          _reader_bits::readToken(line, section);
1142          _reader_bits::readToken(line, caption);
1143
1144          if (line >> c)
1145            throw FormatError("Extra character at the end of line");
1146
1147          if (section == "nodes" && !nodes_done) {
1148            if (_nodes_caption.empty() || _nodes_caption == caption) {
1149              readNodes();
1150              nodes_done = true;
1151            }
1152          } else if ((section == "arcs" || section == "edges") &&
1153                     !arcs_done) {
1154            if (_arcs_caption.empty() || _arcs_caption == caption) {
1155              readArcs();
1156              arcs_done = true;
1157            }
1158          } else if (section == "attributes" && !attributes_done) {
1159            if (_attributes_caption.empty() || _attributes_caption == caption) {
1160              readAttributes();
1161              attributes_done = true;
1162            }
1163          } else {
1164            readLine();
1165            skipSection();
1166          }
1167        } catch (FormatError& error) {
1168          error.line(line_num);
1169          error.file(_filename);
1170          throw;
1171        }
1172      }
1173
1174      if (!nodes_done) {
1175        throw FormatError("Section @nodes not found");
1176      }
1177
1178      if (!arcs_done) {
1179        throw FormatError("Section @arcs not found");
1180      }
1181
1182      if (!attributes_done && !_attributes.empty()) {
1183        throw FormatError("Section @attributes not found");
1184      }
1185
1186    }
1187
1188    /// @}
1189
1190  };
1191
1192  /// \brief Return a \ref DigraphReader class
1193  ///
1194  /// This function just returns a \ref DigraphReader class.
1195  /// \relates DigraphReader
1196  template <typename Digraph>
1197  DigraphReader<Digraph> digraphReader(Digraph& digraph,
1198                                       std::istream& is = std::cin) {
1199    DigraphReader<Digraph> tmp(digraph, is);
1200    return tmp;
1201  }
1202
1203  /// \brief Return a \ref DigraphReader class
1204  ///
1205  /// This function just returns a \ref DigraphReader class.
1206  /// \relates DigraphReader
1207  template <typename Digraph>
1208  DigraphReader<Digraph> digraphReader(Digraph& digraph,
1209                                       const std::string& fn) {
1210    DigraphReader<Digraph> tmp(digraph, fn);
1211    return tmp;
1212  }
1213
1214  /// \brief Return a \ref DigraphReader class
1215  ///
1216  /// This function just returns a \ref DigraphReader class.
1217  /// \relates DigraphReader
1218  template <typename Digraph>
1219  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char* fn) {
1220    DigraphReader<Digraph> tmp(digraph, fn);
1221    return tmp;
1222  }
1223
1224  template <typename Graph>
1225  class GraphReader;
1226
1227  template <typename Graph>
1228  GraphReader<Graph> graphReader(Graph& graph,
1229                                 std::istream& is = std::cin);
1230
1231  template <typename Graph>
1232  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn);
1233
1234  template <typename Graph>
1235  GraphReader<Graph> graphReader(Graph& graph, const char *fn);
1236
1237  /// \ingroup lemon_io
1238  ///
1239  /// \brief \ref lgf-format "LGF" reader for undirected graphs
1240  ///
1241  /// This utility reads an \ref lgf-format "LGF" file.
1242  ///
1243  /// It can be used almost the same way as \c DigraphReader.
1244  /// The only difference is that this class can handle edges and
1245  /// edge maps as well as arcs and arc maps.
1246  ///
1247  /// The columns in the \c \@edges (or \c \@arcs) section are the
1248  /// edge maps. However, if there are two maps with the same name
1249  /// prefixed with \c '+' and \c '-', then these can be read into an
1250  /// arc map.  Similarly, an attribute can be read into an arc, if
1251  /// it's value is an edge label prefixed with \c '+' or \c '-'.
1252  template <typename _Graph>
1253  class GraphReader {
1254  public:
1255
1256    typedef _Graph Graph;
1257    TEMPLATE_GRAPH_TYPEDEFS(Graph);
1258
1259  private:
1260
1261    std::istream* _is;
1262    bool local_is;
1263    std::string _filename;
1264
1265    Graph& _graph;
1266
1267    std::string _nodes_caption;
1268    std::string _edges_caption;
1269    std::string _attributes_caption;
1270
1271    typedef std::map<std::string, Node> NodeIndex;
1272    NodeIndex _node_index;
1273    typedef std::map<std::string, Edge> EdgeIndex;
1274    EdgeIndex _edge_index;
1275
1276    typedef std::vector<std::pair<std::string,
1277      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
1278    NodeMaps _node_maps;
1279
1280    typedef std::vector<std::pair<std::string,
1281      _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
1282    EdgeMaps _edge_maps;
1283
1284    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
1285      Attributes;
1286    Attributes _attributes;
1287
1288    bool _use_nodes;
1289    bool _use_edges;
1290
1291    bool _skip_nodes;
1292    bool _skip_edges;
1293
1294    int line_num;
1295    std::istringstream line;
1296
1297  public:
1298
1299    /// \brief Constructor
1300    ///
1301    /// Construct an undirected graph reader, which reads from the given
1302    /// input stream.
1303    GraphReader(Graph& graph, std::istream& is = std::cin)
1304      : _is(&is), local_is(false), _graph(graph),
1305        _use_nodes(false), _use_edges(false),
1306        _skip_nodes(false), _skip_edges(false) {}
1307
1308    /// \brief Constructor
1309    ///
1310    /// Construct an undirected graph reader, which reads from the given
1311    /// file.
1312    GraphReader(Graph& graph, const std::string& fn)
1313      : _is(new std::ifstream(fn.c_str())), local_is(true),
1314        _filename(fn), _graph(graph),
1315        _use_nodes(false), _use_edges(false),
1316        _skip_nodes(false), _skip_edges(false) {
1317      if (!(*_is)) {
1318        delete _is;
1319        throw IoError("Cannot open file", fn);
1320      }
1321    }
1322
1323    /// \brief Constructor
1324    ///
1325    /// Construct an undirected graph reader, which reads from the given
1326    /// file.
1327    GraphReader(Graph& graph, const char* fn)
1328      : _is(new std::ifstream(fn)), local_is(true),
1329        _filename(fn), _graph(graph),
1330        _use_nodes(false), _use_edges(false),
1331        _skip_nodes(false), _skip_edges(false) {
1332      if (!(*_is)) {
1333        delete _is;
1334        throw IoError("Cannot open file", fn);
1335      }
1336    }
1337
1338    /// \brief Destructor
1339    ~GraphReader() {
1340      for (typename NodeMaps::iterator it = _node_maps.begin();
1341           it != _node_maps.end(); ++it) {
1342        delete it->second;
1343      }
1344
1345      for (typename EdgeMaps::iterator it = _edge_maps.begin();
1346           it != _edge_maps.end(); ++it) {
1347        delete it->second;
1348      }
1349
1350      for (typename Attributes::iterator it = _attributes.begin();
1351           it != _attributes.end(); ++it) {
1352        delete it->second;
1353      }
1354
1355      if (local_is) {
1356        delete _is;
1357      }
1358
1359    }
1360
1361  private:
1362    friend GraphReader<Graph> graphReader<>(Graph& graph, std::istream& is);
1363    friend GraphReader<Graph> graphReader<>(Graph& graph,
1364                                            const std::string& fn);
1365    friend GraphReader<Graph> graphReader<>(Graph& graph, const char *fn);
1366
1367    GraphReader(GraphReader& other)
1368      : _is(other._is), local_is(other.local_is), _graph(other._graph),
1369        _use_nodes(other._use_nodes), _use_edges(other._use_edges),
1370        _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
1371
1372      other._is = 0;
1373      other.local_is = false;
1374
1375      _node_index.swap(other._node_index);
1376      _edge_index.swap(other._edge_index);
1377
1378      _node_maps.swap(other._node_maps);
1379      _edge_maps.swap(other._edge_maps);
1380      _attributes.swap(other._attributes);
1381
1382      _nodes_caption = other._nodes_caption;
1383      _edges_caption = other._edges_caption;
1384      _attributes_caption = other._attributes_caption;
1385
1386    }
1387
1388    GraphReader& operator=(const GraphReader&);
1389
1390  public:
1391
1392    /// \name Reading rules
1393    /// @{
1394
1395    /// \brief Node map reading rule
1396    ///
1397    /// Add a node map reading rule to the reader.
1398    template <typename Map>
1399    GraphReader& nodeMap(const std::string& caption, Map& map) {
1400      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1401      _reader_bits::MapStorageBase<Node>* storage =
1402        new _reader_bits::MapStorage<Node, Map>(map);
1403      _node_maps.push_back(std::make_pair(caption, storage));
1404      return *this;
1405    }
1406
1407    /// \brief Node map reading rule
1408    ///
1409    /// Add a node map reading rule with specialized converter to the
1410    /// reader.
1411    template <typename Map, typename Converter>
1412    GraphReader& nodeMap(const std::string& caption, Map& map,
1413                           const Converter& converter = Converter()) {
1414      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1415      _reader_bits::MapStorageBase<Node>* storage =
1416        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
1417      _node_maps.push_back(std::make_pair(caption, storage));
1418      return *this;
1419    }
1420
1421    /// \brief Edge map reading rule
1422    ///
1423    /// Add an edge map reading rule to the reader.
1424    template <typename Map>
1425    GraphReader& edgeMap(const std::string& caption, Map& map) {
1426      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1427      _reader_bits::MapStorageBase<Edge>* storage =
1428        new _reader_bits::MapStorage<Edge, Map>(map);
1429      _edge_maps.push_back(std::make_pair(caption, storage));
1430      return *this;
1431    }
1432
1433    /// \brief Edge map reading rule
1434    ///
1435    /// Add an edge map reading rule with specialized converter to the
1436    /// reader.
1437    template <typename Map, typename Converter>
1438    GraphReader& edgeMap(const std::string& caption, Map& map,
1439                          const Converter& converter = Converter()) {
1440      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1441      _reader_bits::MapStorageBase<Edge>* storage =
1442        new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
1443      _edge_maps.push_back(std::make_pair(caption, storage));
1444      return *this;
1445    }
1446
1447    /// \brief Arc map reading rule
1448    ///
1449    /// Add an arc map reading rule to the reader.
1450    template <typename Map>
1451    GraphReader& arcMap(const std::string& caption, Map& map) {
1452      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1453      _reader_bits::MapStorageBase<Edge>* forward_storage =
1454        new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
1455      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1456      _reader_bits::MapStorageBase<Edge>* backward_storage =
1457        new _reader_bits::GraphArcMapStorage<Graph, false, Map>(_graph, map);
1458      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1459      return *this;
1460    }
1461
1462    /// \brief Arc map reading rule
1463    ///
1464    /// Add an arc map reading rule with specialized converter to the
1465    /// reader.
1466    template <typename Map, typename Converter>
1467    GraphReader& arcMap(const std::string& caption, Map& map,
1468                          const Converter& converter = Converter()) {
1469      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1470      _reader_bits::MapStorageBase<Edge>* forward_storage =
1471        new _reader_bits::GraphArcMapStorage<Graph, true, Map, Converter>
1472        (_graph, map, converter);
1473      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1474      _reader_bits::MapStorageBase<Edge>* backward_storage =
1475        new _reader_bits::GraphArcMapStorage<Graph, false, Map, Converter>
1476        (_graph, map, converter);
1477      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1478      return *this;
1479    }
1480
1481    /// \brief Attribute reading rule
1482    ///
1483    /// Add an attribute reading rule to the reader.
1484    template <typename Value>
1485    GraphReader& attribute(const std::string& caption, Value& value) {
1486      _reader_bits::ValueStorageBase* storage =
1487        new _reader_bits::ValueStorage<Value>(value);
1488      _attributes.insert(std::make_pair(caption, storage));
1489      return *this;
1490    }
1491
1492    /// \brief Attribute reading rule
1493    ///
1494    /// Add an attribute reading rule with specialized converter to the
1495    /// reader.
1496    template <typename Value, typename Converter>
1497    GraphReader& attribute(const std::string& caption, Value& value,
1498                             const Converter& converter = Converter()) {
1499      _reader_bits::ValueStorageBase* storage =
1500        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
1501      _attributes.insert(std::make_pair(caption, storage));
1502      return *this;
1503    }
1504
1505    /// \brief Node reading rule
1506    ///
1507    /// Add a node reading rule to reader.
1508    GraphReader& node(const std::string& caption, Node& node) {
1509      typedef _reader_bits::MapLookUpConverter<Node> Converter;
1510      Converter converter(_node_index);
1511      _reader_bits::ValueStorageBase* storage =
1512        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
1513      _attributes.insert(std::make_pair(caption, storage));
1514      return *this;
1515    }
1516
1517    /// \brief Edge reading rule
1518    ///
1519    /// Add an edge reading rule to reader.
1520    GraphReader& edge(const std::string& caption, Edge& edge) {
1521      typedef _reader_bits::MapLookUpConverter<Edge> Converter;
1522      Converter converter(_edge_index);
1523      _reader_bits::ValueStorageBase* storage =
1524        new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
1525      _attributes.insert(std::make_pair(caption, storage));
1526      return *this;
1527    }
1528
1529    /// \brief Arc reading rule
1530    ///
1531    /// Add an arc reading rule to reader.
1532    GraphReader& arc(const std::string& caption, Arc& arc) {
1533      typedef _reader_bits::GraphArcLookUpConverter<Graph> Converter;
1534      Converter converter(_graph, _edge_index);
1535      _reader_bits::ValueStorageBase* storage =
1536        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
1537      _attributes.insert(std::make_pair(caption, storage));
1538      return *this;
1539    }
1540
1541    /// @}
1542
1543    /// \name Select section by name
1544    /// @{
1545
1546    /// \brief Set \c \@nodes section to be read
1547    ///
1548    /// Set \c \@nodes section to be read.
1549    GraphReader& nodes(const std::string& caption) {
1550      _nodes_caption = caption;
1551      return *this;
1552    }
1553
1554    /// \brief Set \c \@edges section to be read
1555    ///
1556    /// Set \c \@edges section to be read.
1557    GraphReader& edges(const std::string& caption) {
1558      _edges_caption = caption;
1559      return *this;
1560    }
1561
1562    /// \brief Set \c \@attributes section to be read
1563    ///
1564    /// Set \c \@attributes section to be read.
1565    GraphReader& attributes(const std::string& caption) {
1566      _attributes_caption = caption;
1567      return *this;
1568    }
1569
1570    /// @}
1571
1572    /// \name Using previously constructed node or edge set
1573    /// @{
1574
1575    /// \brief Use previously constructed node set
1576    ///
1577    /// Use previously constructed node set, and specify the node
1578    /// label map.
1579    template <typename Map>
1580    GraphReader& useNodes(const Map& map) {
1581      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1582      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1583      _use_nodes = true;
1584      _writer_bits::DefaultConverter<typename Map::Value> converter;
1585      for (NodeIt n(_graph); n != INVALID; ++n) {
1586        _node_index.insert(std::make_pair(converter(map[n]), n));
1587      }
1588      return *this;
1589    }
1590
1591    /// \brief Use previously constructed node set
1592    ///
1593    /// Use previously constructed node set, and specify the node
1594    /// label map and a functor which converts the label map values to
1595    /// \c std::string.
1596    template <typename Map, typename Converter>
1597    GraphReader& useNodes(const Map& map,
1598                            const Converter& converter = Converter()) {
1599      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1600      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1601      _use_nodes = true;
1602      for (NodeIt n(_graph); n != INVALID; ++n) {
1603        _node_index.insert(std::make_pair(converter(map[n]), n));
1604      }
1605      return *this;
1606    }
1607
1608    /// \brief Use previously constructed edge set
1609    ///
1610    /// Use previously constructed edge set, and specify the edge
1611    /// label map.
1612    template <typename Map>
1613    GraphReader& useEdges(const Map& map) {
1614      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1615      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1616      _use_edges = true;
1617      _writer_bits::DefaultConverter<typename Map::Value> converter;
1618      for (EdgeIt a(_graph); a != INVALID; ++a) {
1619        _edge_index.insert(std::make_pair(converter(map[a]), a));
1620      }
1621      return *this;
1622    }
1623
1624    /// \brief Use previously constructed edge set
1625    ///
1626    /// Use previously constructed edge set, and specify the edge
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& useEdges(const Map& map,
1631                            const Converter& converter = Converter()) {
1632      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1633      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1634      _use_edges = true;
1635      for (EdgeIt a(_graph); a != INVALID; ++a) {
1636        _edge_index.insert(std::make_pair(converter(map[a]), a));
1637      }
1638      return *this;
1639    }
1640
1641    /// \brief Skip the reading of node section
1642    ///
1643    /// Omit the reading of the node section. This implies that each node
1644    /// map reading rule will be abandoned, and the nodes of the graph
1645    /// will not be constructed, which usually cause that the edge set
1646    /// could not be read due to lack of node name
1647    /// could not be read due to lack of node name resolving.
1648    /// Therefore \c skipEdges() function should also be used, or
1649    /// \c useNodes() should be used to specify the label of the nodes.
1650    GraphReader& skipNodes() {
1651      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
1652      _skip_nodes = true;
1653      return *this;
1654    }
1655
1656    /// \brief Skip the reading of edge section
1657    ///
1658    /// Omit the reading of the edge section. This implies that each edge
1659    /// map reading rule will be abandoned, and the edges of the graph
1660    /// will not be constructed.
1661    GraphReader& skipEdges() {
1662      LEMON_ASSERT(!_skip_edges, "Skip edges already set");
1663      _skip_edges = true;
1664      return *this;
1665    }
1666
1667    /// @}
1668
1669  private:
1670
1671    bool readLine() {
1672      std::string str;
1673      while(++line_num, std::getline(*_is, str)) {
1674        line.clear(); line.str(str);
1675        char c;
1676        if (line >> std::ws >> c && c != '#') {
1677          line.putback(c);
1678          return true;
1679        }
1680      }
1681      return false;
1682    }
1683
1684    bool readSuccess() {
1685      return static_cast<bool>(*_is);
1686    }
1687
1688    void skipSection() {
1689      char c;
1690      while (readSuccess() && line >> c && c != '@') {
1691        readLine();
1692      }
1693      line.putback(c);
1694    }
1695
1696    void readNodes() {
1697
1698      std::vector<int> map_index(_node_maps.size());
1699      int map_num, label_index;
1700
1701      char c;
1702      if (!readLine() || !(line >> c) || c == '@') {
1703        if (readSuccess() && line) line.putback(c);
1704        if (!_node_maps.empty())
1705          throw FormatError("Cannot find map names");
1706        return;
1707      }
1708      line.putback(c);
1709
1710      {
1711        std::map<std::string, int> maps;
1712
1713        std::string map;
1714        int index = 0;
1715        while (_reader_bits::readToken(line, map)) {
1716          if (maps.find(map) != maps.end()) {
1717            std::ostringstream msg;
1718            msg << "Multiple occurence of node map: " << map;
1719            throw FormatError(msg.str());
1720          }
1721          maps.insert(std::make_pair(map, index));
1722          ++index;
1723        }
1724
1725        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1726          std::map<std::string, int>::iterator jt =
1727            maps.find(_node_maps[i].first);
1728          if (jt == maps.end()) {
1729            std::ostringstream msg;
1730            msg << "Map not found: " << _node_maps[i].first;
1731            throw FormatError(msg.str());
1732          }
1733          map_index[i] = jt->second;
1734        }
1735
1736        {
1737          std::map<std::string, int>::iterator jt = maps.find("label");
1738          if (jt != maps.end()) {
1739            label_index = jt->second;
1740          } else {
1741            label_index = -1;
1742          }
1743        }
1744        map_num = maps.size();
1745      }
1746
1747      while (readLine() && line >> c && c != '@') {
1748        line.putback(c);
1749
1750        std::vector<std::string> tokens(map_num);
1751        for (int i = 0; i < map_num; ++i) {
1752          if (!_reader_bits::readToken(line, tokens[i])) {
1753            std::ostringstream msg;
1754            msg << "Column not found (" << i + 1 << ")";
1755            throw FormatError(msg.str());
1756          }
1757        }
1758        if (line >> std::ws >> c)
1759          throw FormatError("Extra character at the end of line");
1760
1761        Node n;
1762        if (!_use_nodes) {
1763          n = _graph.addNode();
1764          if (label_index != -1)
1765            _node_index.insert(std::make_pair(tokens[label_index], n));
1766        } else {
1767          if (label_index == -1)
1768            throw FormatError("Label map not found");
1769          typename std::map<std::string, Node>::iterator it =
1770            _node_index.find(tokens[label_index]);
1771          if (it == _node_index.end()) {
1772            std::ostringstream msg;
1773            msg << "Node with label not found: " << tokens[label_index];
1774            throw FormatError(msg.str());
1775          }
1776          n = it->second;
1777        }
1778
1779        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1780          _node_maps[i].second->set(n, tokens[map_index[i]]);
1781        }
1782
1783      }
1784      if (readSuccess()) {
1785        line.putback(c);
1786      }
1787    }
1788
1789    void readEdges() {
1790
1791      std::vector<int> map_index(_edge_maps.size());
1792      int map_num, label_index;
1793
1794      char c;
1795      if (!readLine() || !(line >> c) || c == '@') {
1796        if (readSuccess() && line) line.putback(c);
1797        if (!_edge_maps.empty())
1798          throw FormatError("Cannot find map names");
1799        return;
1800      }
1801      line.putback(c);
1802
1803      {
1804        std::map<std::string, int> maps;
1805
1806        std::string map;
1807        int index = 0;
1808        while (_reader_bits::readToken(line, map)) {
1809          if (maps.find(map) != maps.end()) {
1810            std::ostringstream msg;
1811            msg << "Multiple occurence of edge map: " << map;
1812            throw FormatError(msg.str());
1813          }
1814          maps.insert(std::make_pair(map, index));
1815          ++index;
1816        }
1817
1818        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1819          std::map<std::string, int>::iterator jt =
1820            maps.find(_edge_maps[i].first);
1821          if (jt == maps.end()) {
1822            std::ostringstream msg;
1823            msg << "Map not found: " << _edge_maps[i].first;
1824            throw FormatError(msg.str());
1825          }
1826          map_index[i] = jt->second;
1827        }
1828
1829        {
1830          std::map<std::string, int>::iterator jt = maps.find("label");
1831          if (jt != maps.end()) {
1832            label_index = jt->second;
1833          } else {
1834            label_index = -1;
1835          }
1836        }
1837        map_num = maps.size();
1838      }
1839
1840      while (readLine() && line >> c && c != '@') {
1841        line.putback(c);
1842
1843        std::string source_token;
1844        std::string target_token;
1845
1846        if (!_reader_bits::readToken(line, source_token))
1847          throw FormatError("Node u not found");
1848
1849        if (!_reader_bits::readToken(line, target_token))
1850          throw FormatError("Node v not found");
1851
1852        std::vector<std::string> tokens(map_num);
1853        for (int i = 0; i < map_num; ++i) {
1854          if (!_reader_bits::readToken(line, tokens[i])) {
1855            std::ostringstream msg;
1856            msg << "Column not found (" << i + 1 << ")";
1857            throw FormatError(msg.str());
1858          }
1859        }
1860        if (line >> std::ws >> c)
1861          throw FormatError("Extra character at the end of line");
1862
1863        Edge e;
1864        if (!_use_edges) {
1865
1866          typename NodeIndex::iterator it;
1867
1868          it = _node_index.find(source_token);
1869          if (it == _node_index.end()) {
1870            std::ostringstream msg;
1871            msg << "Item not found: " << source_token;
1872            throw FormatError(msg.str());
1873          }
1874          Node source = it->second;
1875
1876          it = _node_index.find(target_token);
1877          if (it == _node_index.end()) {
1878            std::ostringstream msg;
1879            msg << "Item not found: " << target_token;
1880            throw FormatError(msg.str());
1881          }
1882          Node target = it->second;
1883
1884          e = _graph.addEdge(source, target);
1885          if (label_index != -1)
1886            _edge_index.insert(std::make_pair(tokens[label_index], e));
1887        } else {
1888          if (label_index == -1)
1889            throw FormatError("Label map not found");
1890          typename std::map<std::string, Edge>::iterator it =
1891            _edge_index.find(tokens[label_index]);
1892          if (it == _edge_index.end()) {
1893            std::ostringstream msg;
1894            msg << "Edge with label not found: " << tokens[label_index];
1895            throw FormatError(msg.str());
1896          }
1897          e = it->second;
1898        }
1899
1900        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1901          _edge_maps[i].second->set(e, tokens[map_index[i]]);
1902        }
1903
1904      }
1905      if (readSuccess()) {
1906        line.putback(c);
1907      }
1908    }
1909
1910    void readAttributes() {
1911
1912      std::set<std::string> read_attr;
1913
1914      char c;
1915      while (readLine() && line >> c && c != '@') {
1916        line.putback(c);
1917
1918        std::string attr, token;
1919        if (!_reader_bits::readToken(line, attr))
1920          throw FormatError("Attribute name not found");
1921        if (!_reader_bits::readToken(line, token))
1922          throw FormatError("Attribute value not found");
1923        if (line >> c)
1924          throw FormatError("Extra character at the end of line");
1925
1926        {
1927          std::set<std::string>::iterator it = read_attr.find(attr);
1928          if (it != read_attr.end()) {
1929            std::ostringstream msg;
1930            msg << "Multiple occurence of attribute: " << attr;
1931            throw FormatError(msg.str());
1932          }
1933          read_attr.insert(attr);
1934        }
1935
1936        {
1937          typename Attributes::iterator it = _attributes.lower_bound(attr);
1938          while (it != _attributes.end() && it->first == attr) {
1939            it->second->set(token);
1940            ++it;
1941          }
1942        }
1943
1944      }
1945      if (readSuccess()) {
1946        line.putback(c);
1947      }
1948      for (typename Attributes::iterator it = _attributes.begin();
1949           it != _attributes.end(); ++it) {
1950        if (read_attr.find(it->first) == read_attr.end()) {
1951          std::ostringstream msg;
1952          msg << "Attribute not found: " << it->first;
1953          throw FormatError(msg.str());
1954        }
1955      }
1956    }
1957
1958  public:
1959
1960    /// \name Execution of the reader
1961    /// @{
1962
1963    /// \brief Start the batch processing
1964    ///
1965    /// This function starts the batch processing
1966    void run() {
1967
1968      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1969
1970      bool nodes_done = _skip_nodes;
1971      bool edges_done = _skip_edges;
1972      bool attributes_done = false;
1973
1974      line_num = 0;
1975      readLine();
1976      skipSection();
1977
1978      while (readSuccess()) {
1979        try {
1980          char c;
1981          std::string section, caption;
1982          line >> c;
1983          _reader_bits::readToken(line, section);
1984          _reader_bits::readToken(line, caption);
1985
1986          if (line >> c)
1987            throw FormatError("Extra character at the end of line");
1988
1989          if (section == "nodes" && !nodes_done) {
1990            if (_nodes_caption.empty() || _nodes_caption == caption) {
1991              readNodes();
1992              nodes_done = true;
1993            }
1994          } else if ((section == "edges" || section == "arcs") &&
1995                     !edges_done) {
1996            if (_edges_caption.empty() || _edges_caption == caption) {
1997              readEdges();
1998              edges_done = true;
1999            }
2000          } else if (section == "attributes" && !attributes_done) {
2001            if (_attributes_caption.empty() || _attributes_caption == caption) {
2002              readAttributes();
2003              attributes_done = true;
2004            }
2005          } else {
2006            readLine();
2007            skipSection();
2008          }
2009        } catch (FormatError& error) {
2010          error.line(line_num);
2011          error.file(_filename);
2012          throw;
2013        }
2014      }
2015
2016      if (!nodes_done) {
2017        throw FormatError("Section @nodes not found");
2018      }
2019
2020      if (!edges_done) {
2021        throw FormatError("Section @edges not found");
2022      }
2023
2024      if (!attributes_done && !_attributes.empty()) {
2025        throw FormatError("Section @attributes not found");
2026      }
2027
2028    }
2029
2030    /// @}
2031
2032  };
2033
2034  /// \brief Return a \ref GraphReader class
2035  ///
2036  /// This function just returns a \ref GraphReader class.
2037  /// \relates GraphReader
2038  template <typename Graph>
2039  GraphReader<Graph> graphReader(Graph& graph, std::istream& is = std::cin) {
2040    GraphReader<Graph> tmp(graph, is);
2041    return tmp;
2042  }
2043
2044  /// \brief Return a \ref GraphReader class
2045  ///
2046  /// This function just returns a \ref GraphReader class.
2047  /// \relates GraphReader
2048  template <typename Graph>
2049  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {
2050    GraphReader<Graph> tmp(graph, fn);
2051    return tmp;
2052  }
2053
2054  /// \brief Return a \ref GraphReader class
2055  ///
2056  /// This function just returns a \ref GraphReader class.
2057  /// \relates GraphReader
2058  template <typename Graph>
2059  GraphReader<Graph> graphReader(Graph& graph, const char* fn) {
2060    GraphReader<Graph> tmp(graph, fn);
2061    return tmp;
2062  }
2063
2064  class SectionReader;
2065
2066  SectionReader sectionReader(std::istream& is);
2067  SectionReader sectionReader(const std::string& fn);
2068  SectionReader sectionReader(const char* fn);
2069
2070  /// \ingroup lemon_io
2071  ///
2072  /// \brief Section reader class
2073  ///
2074  /// In the \ref lgf-format "LGF" file extra sections can be placed,
2075  /// which contain any data in arbitrary format. Such sections can be
2076  /// read with this class. A reading rule can be added to the class
2077  /// with two different functions. With the \c sectionLines() function a
2078  /// functor can process the section line-by-line, while with the \c
2079  /// sectionStream() member the section can be read from an input
2080  /// stream.
2081  class SectionReader {
2082  private:
2083
2084    std::istream* _is;
2085    bool local_is;
2086    std::string _filename;
2087
2088    typedef std::map<std::string, _reader_bits::Section*> Sections;
2089    Sections _sections;
2090
2091    int line_num;
2092    std::istringstream line;
2093
2094  public:
2095
2096    /// \brief Constructor
2097    ///
2098    /// Construct a section reader, which reads from the given input
2099    /// stream.
2100    SectionReader(std::istream& is)
2101      : _is(&is), local_is(false) {}
2102
2103    /// \brief Constructor
2104    ///
2105    /// Construct a section reader, which reads from the given file.
2106    SectionReader(const std::string& fn)
2107      : _is(new std::ifstream(fn.c_str())), local_is(true),
2108        _filename(fn) {
2109      if (!(*_is)) {
2110        delete _is;
2111        throw IoError("Cannot open file", fn);
2112      }
2113    }
2114
2115    /// \brief Constructor
2116    ///
2117    /// Construct a section reader, which reads from the given file.
2118    SectionReader(const char* fn)
2119      : _is(new std::ifstream(fn)), local_is(true),
2120        _filename(fn) {
2121      if (!(*_is)) {
2122        delete _is;
2123        throw IoError("Cannot open file", fn);
2124      }
2125    }
2126
2127    /// \brief Destructor
2128    ~SectionReader() {
2129      for (Sections::iterator it = _sections.begin();
2130           it != _sections.end(); ++it) {
2131        delete it->second;
2132      }
2133
2134      if (local_is) {
2135        delete _is;
2136      }
2137
2138    }
2139
2140  private:
2141
2142    friend SectionReader sectionReader(std::istream& is);
2143    friend SectionReader sectionReader(const std::string& fn);
2144    friend SectionReader sectionReader(const char* fn);
2145
2146    SectionReader(SectionReader& other)
2147      : _is(other._is), local_is(other.local_is) {
2148
2149      other._is = 0;
2150      other.local_is = false;
2151
2152      _sections.swap(other._sections);
2153    }
2154
2155    SectionReader& operator=(const SectionReader&);
2156
2157  public:
2158
2159    /// \name Section readers
2160    /// @{
2161
2162    /// \brief Add a section processor with line oriented reading
2163    ///
2164    /// The first parameter is the type descriptor of the section, the
2165    /// second is a functor, which takes just one \c std::string
2166    /// parameter. At the reading process, each line of the section
2167    /// will be given to the functor object. However, the empty lines
2168    /// and the comment lines are filtered out, and the leading
2169    /// whitespaces are trimmed from each processed string.
2170    ///
2171    /// For example let's see a section, which contain several
2172    /// integers, which should be inserted into a vector.
2173    ///\code
2174    ///  @numbers
2175    ///  12 45 23
2176    ///  4
2177    ///  23 6
2178    ///\endcode
2179    ///
2180    /// The functor is implemented as a struct:
2181    ///\code
2182    ///  struct NumberSection {
2183    ///    std::vector<int>& _data;
2184    ///    NumberSection(std::vector<int>& data) : _data(data) {}
2185    ///    void operator()(const std::string& line) {
2186    ///      std::istringstream ls(line);
2187    ///      int value;
2188    ///      while (ls >> value) _data.push_back(value);
2189    ///    }
2190    ///  };
2191    ///
2192    ///  // ...
2193    ///
2194    ///  reader.sectionLines("numbers", NumberSection(vec));
2195    ///\endcode
2196    template <typename Functor>
2197    SectionReader& sectionLines(const std::string& type, Functor functor) {
2198      LEMON_ASSERT(!type.empty(), "Type is empty.");
2199      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2200                   "Multiple reading of section.");
2201      _sections.insert(std::make_pair(type,
2202        new _reader_bits::LineSection<Functor>(functor)));
2203      return *this;
2204    }
2205
2206
2207    /// \brief Add a section processor with stream oriented reading
2208    ///
2209    /// The first parameter is the type of the section, the second is
2210    /// a functor, which takes an \c std::istream& and an \c int&
2211    /// parameter, the latter regard to the line number of stream. The
2212    /// functor can read the input while the section go on, and the
2213    /// line number should be modified accordingly.
2214    template <typename Functor>
2215    SectionReader& sectionStream(const std::string& type, Functor functor) {
2216      LEMON_ASSERT(!type.empty(), "Type is empty.");
2217      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2218                   "Multiple reading of section.");
2219      _sections.insert(std::make_pair(type,
2220         new _reader_bits::StreamSection<Functor>(functor)));
2221      return *this;
2222    }
2223
2224    /// @}
2225
2226  private:
2227
2228    bool readLine() {
2229      std::string str;
2230      while(++line_num, std::getline(*_is, str)) {
2231        line.clear(); line.str(str);
2232        char c;
2233        if (line >> std::ws >> c && c != '#') {
2234          line.putback(c);
2235          return true;
2236        }
2237      }
2238      return false;
2239    }
2240
2241    bool readSuccess() {
2242      return static_cast<bool>(*_is);
2243    }
2244
2245    void skipSection() {
2246      char c;
2247      while (readSuccess() && line >> c && c != '@') {
2248        readLine();
2249      }
2250      line.putback(c);
2251    }
2252
2253  public:
2254
2255
2256    /// \name Execution of the reader
2257    /// @{
2258
2259    /// \brief Start the batch processing
2260    ///
2261    /// This function starts the batch processing.
2262    void run() {
2263
2264      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
2265
2266      std::set<std::string> extra_sections;
2267
2268      line_num = 0;
2269      readLine();
2270      skipSection();
2271
2272      while (readSuccess()) {
2273        try {
2274          char c;
2275          std::string section, caption;
2276          line >> c;
2277          _reader_bits::readToken(line, section);
2278          _reader_bits::readToken(line, caption);
2279
2280          if (line >> c)
2281            throw FormatError("Extra character at the end of line");
2282
2283          if (extra_sections.find(section) != extra_sections.end()) {
2284            std::ostringstream msg;
2285            msg << "Multiple occurence of section: " << section;
2286            throw FormatError(msg.str());
2287          }
2288          Sections::iterator it = _sections.find(section);
2289          if (it != _sections.end()) {
2290            extra_sections.insert(section);
2291            it->second->process(*_is, line_num);
2292          }
2293          readLine();
2294          skipSection();
2295        } catch (FormatError& error) {
2296          error.line(line_num);
2297          error.file(_filename);
2298          throw;
2299        }
2300      }
2301      for (Sections::iterator it = _sections.begin();
2302           it != _sections.end(); ++it) {
2303        if (extra_sections.find(it->first) == extra_sections.end()) {
2304          std::ostringstream os;
2305          os << "Cannot find section: " << it->first;
2306          throw FormatError(os.str());
2307        }
2308      }
2309    }
2310
2311    /// @}
2312
2313  };
2314
2315  /// \brief Return a \ref SectionReader class
2316  ///
2317  /// This function just returns a \ref SectionReader class.
2318  /// \relates SectionReader
2319  inline SectionReader sectionReader(std::istream& is) {
2320    SectionReader tmp(is);
2321    return tmp;
2322  }
2323
2324  /// \brief Return a \ref SectionReader class
2325  ///
2326  /// This function just returns a \ref SectionReader class.
2327  /// \relates SectionReader
2328  inline SectionReader sectionReader(const std::string& fn) {
2329    SectionReader tmp(fn);
2330    return tmp;
2331  }
2332
2333  /// \brief Return a \ref SectionReader class
2334  ///
2335  /// This function just returns a \ref SectionReader class.
2336  /// \relates SectionReader
2337  inline SectionReader sectionReader(const char* fn) {
2338    SectionReader tmp(fn);
2339    return tmp;
2340  }
2341
2342  /// \ingroup lemon_io
2343  ///
2344  /// \brief Reader for the contents of the \ref lgf-format "LGF" file
2345  ///
2346  /// This class can be used to read the sections, the map names and
2347  /// the attributes from a file. Usually, the LEMON programs know
2348  /// that, which type of graph, which maps and which attributes
2349  /// should be read from a file, but in general tools (like glemon)
2350  /// the contents of an LGF file should be guessed somehow. This class
2351  /// reads the graph and stores the appropriate information for
2352  /// reading the graph.
2353  ///
2354  ///\code
2355  /// LgfContents contents("graph.lgf");
2356  /// contents.run();
2357  ///
2358  /// // Does it contain any node section and arc section?
2359  /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
2360  ///   std::cerr << "Failure, cannot find graph." << std::endl;
2361  ///   return -1;
2362  /// }
2363  /// std::cout << "The name of the default node section: "
2364  ///           << contents.nodeSection(0) << std::endl;
2365  /// std::cout << "The number of the arc maps: "
2366  ///           << contents.arcMaps(0).size() << std::endl;
2367  /// std::cout << "The name of second arc map: "
2368  ///           << contents.arcMaps(0)[1] << std::endl;
2369  ///\endcode
2370  class LgfContents {
2371  private:
2372
2373    std::istream* _is;
2374    bool local_is;
2375
2376    std::vector<std::string> _node_sections;
2377    std::vector<std::string> _edge_sections;
2378    std::vector<std::string> _attribute_sections;
2379    std::vector<std::string> _extra_sections;
2380
2381    std::vector<bool> _arc_sections;
2382
2383    std::vector<std::vector<std::string> > _node_maps;
2384    std::vector<std::vector<std::string> > _edge_maps;
2385
2386    std::vector<std::vector<std::string> > _attributes;
2387
2388
2389    int line_num;
2390    std::istringstream line;
2391
2392  public:
2393
2394    /// \brief Constructor
2395    ///
2396    /// Construct an \e LGF contents reader, which reads from the given
2397    /// input stream.
2398    LgfContents(std::istream& is)
2399      : _is(&is), local_is(false) {}
2400
2401    /// \brief Constructor
2402    ///
2403    /// Construct an \e LGF contents reader, which reads from the given
2404    /// file.
2405    LgfContents(const std::string& fn)
2406      : _is(new std::ifstream(fn.c_str())), local_is(true) {
2407      if (!(*_is)) {
2408        delete _is;
2409        throw IoError("Cannot open file", fn);
2410      }
2411    }
2412
2413    /// \brief Constructor
2414    ///
2415    /// Construct an \e LGF contents reader, which reads from the given
2416    /// file.
2417    LgfContents(const char* fn)
2418      : _is(new std::ifstream(fn)), local_is(true) {
2419      if (!(*_is)) {
2420        delete _is;
2421        throw IoError("Cannot open file", fn);
2422      }
2423    }
2424
2425    /// \brief Destructor
2426    ~LgfContents() {
2427      if (local_is) delete _is;
2428    }
2429
2430  private:
2431
2432    LgfContents(const LgfContents&);
2433    LgfContents& operator=(const LgfContents&);
2434
2435  public:
2436
2437
2438    /// \name Node sections
2439    /// @{
2440
2441    /// \brief Gives back the number of node sections in the file.
2442    ///
2443    /// Gives back the number of node sections in the file.
2444    int nodeSectionNum() const {
2445      return _node_sections.size();
2446    }
2447
2448    /// \brief Returns the node section name at the given position.
2449    ///
2450    /// Returns the node section name at the given position.
2451    const std::string& nodeSection(int i) const {
2452      return _node_sections[i];
2453    }
2454
2455    /// \brief Gives back the node maps for the given section.
2456    ///
2457    /// Gives back the node maps for the given section.
2458    const std::vector<std::string>& nodeMapNames(int i) const {
2459      return _node_maps[i];
2460    }
2461
2462    /// @}
2463
2464    /// \name Arc/Edge sections
2465    /// @{
2466
2467    /// \brief Gives back the number of arc/edge sections in the file.
2468    ///
2469    /// Gives back the number of arc/edge sections in the file.
2470    /// \note It is synonym of \c edgeSectionNum().
2471    int arcSectionNum() const {
2472      return _edge_sections.size();
2473    }
2474
2475    /// \brief Returns the arc/edge section name at the given position.
2476    ///
2477    /// Returns the arc/edge section name at the given position.
2478    /// \note It is synonym of \c edgeSection().
2479    const std::string& arcSection(int i) const {
2480      return _edge_sections[i];
2481    }
2482
2483    /// \brief Gives back the arc/edge maps for the given section.
2484    ///
2485    /// Gives back the arc/edge maps for the given section.
2486    /// \note It is synonym of \c edgeMapNames().
2487    const std::vector<std::string>& arcMapNames(int i) const {
2488      return _edge_maps[i];
2489    }
2490
2491    /// @}
2492
2493    /// \name Synonyms
2494    /// @{
2495
2496    /// \brief Gives back the number of arc/edge sections in the file.
2497    ///
2498    /// Gives back the number of arc/edge sections in the file.
2499    /// \note It is synonym of \c arcSectionNum().
2500    int edgeSectionNum() const {
2501      return _edge_sections.size();
2502    }
2503
2504    /// \brief Returns the section name at the given position.
2505    ///
2506    /// Returns the section name at the given position.
2507    /// \note It is synonym of \c arcSection().
2508    const std::string& edgeSection(int i) const {
2509      return _edge_sections[i];
2510    }
2511
2512    /// \brief Gives back the edge maps for the given section.
2513    ///
2514    /// Gives back the edge maps for the given section.
2515    /// \note It is synonym of \c arcMapNames().
2516    const std::vector<std::string>& edgeMapNames(int i) const {
2517      return _edge_maps[i];
2518    }
2519
2520    /// @}
2521
2522    /// \name Attribute sections
2523    /// @{
2524
2525    /// \brief Gives back the number of attribute sections in the file.
2526    ///
2527    /// Gives back the number of attribute sections in the file.
2528    int attributeSectionNum() const {
2529      return _attribute_sections.size();
2530    }
2531
2532    /// \brief Returns the attribute section name at the given position.
2533    ///
2534    /// Returns the attribute section name at the given position.
2535    const std::string& attributeSectionNames(int i) const {
2536      return _attribute_sections[i];
2537    }
2538
2539    /// \brief Gives back the attributes for the given section.
2540    ///
2541    /// Gives back the attributes for the given section.
2542    const std::vector<std::string>& attributes(int i) const {
2543      return _attributes[i];
2544    }
2545
2546    /// @}
2547
2548    /// \name Extra sections
2549    /// @{
2550
2551    /// \brief Gives back the number of extra sections in the file.
2552    ///
2553    /// Gives back the number of extra sections in the file.
2554    int extraSectionNum() const {
2555      return _extra_sections.size();
2556    }
2557
2558    /// \brief Returns the extra section type at the given position.
2559    ///
2560    /// Returns the section type at the given position.
2561    const std::string& extraSection(int i) const {
2562      return _extra_sections[i];
2563    }
2564
2565    /// @}
2566
2567  private:
2568
2569    bool readLine() {
2570      std::string str;
2571      while(++line_num, std::getline(*_is, str)) {
2572        line.clear(); line.str(str);
2573        char c;
2574        if (line >> std::ws >> c && c != '#') {
2575          line.putback(c);
2576          return true;
2577        }
2578      }
2579      return false;
2580    }
2581
2582    bool readSuccess() {
2583      return static_cast<bool>(*_is);
2584    }
2585
2586    void skipSection() {
2587      char c;
2588      while (readSuccess() && line >> c && c != '@') {
2589        readLine();
2590      }
2591      line.putback(c);
2592    }
2593
2594    void readMaps(std::vector<std::string>& maps) {
2595      char c;
2596      if (!readLine() || !(line >> c) || c == '@') {
2597        if (readSuccess() && line) line.putback(c);
2598        return;
2599      }
2600      line.putback(c);
2601      std::string map;
2602      while (_reader_bits::readToken(line, map)) {
2603        maps.push_back(map);
2604      }
2605    }
2606
2607    void readAttributes(std::vector<std::string>& attrs) {
2608      readLine();
2609      char c;
2610      while (readSuccess() && line >> c && c != '@') {
2611        line.putback(c);
2612        std::string attr;
2613        _reader_bits::readToken(line, attr);
2614        attrs.push_back(attr);
2615        readLine();
2616      }
2617      line.putback(c);
2618    }
2619
2620  public:
2621
2622    /// \name Execution of the contents reader
2623    /// @{
2624
2625    /// \brief Starts the reading
2626    ///
2627    /// This function starts the reading.
2628    void run() {
2629
2630      readLine();
2631      skipSection();
2632
2633      while (readSuccess()) {
2634
2635        char c;
2636        line >> c;
2637
2638        std::string section, caption;
2639        _reader_bits::readToken(line, section);
2640        _reader_bits::readToken(line, caption);
2641
2642        if (section == "nodes") {
2643          _node_sections.push_back(caption);
2644          _node_maps.push_back(std::vector<std::string>());
2645          readMaps(_node_maps.back());
2646          readLine(); skipSection();
2647        } else if (section == "arcs" || section == "edges") {
2648          _edge_sections.push_back(caption);
2649          _arc_sections.push_back(section == "arcs");
2650          _edge_maps.push_back(std::vector<std::string>());
2651          readMaps(_edge_maps.back());
2652          readLine(); skipSection();
2653        } else if (section == "attributes") {
2654          _attribute_sections.push_back(caption);
2655          _attributes.push_back(std::vector<std::string>());
2656          readAttributes(_attributes.back());
2657        } else {
2658          _extra_sections.push_back(section);
2659          readLine(); skipSection();
2660        }
2661      }
2662    }
2663
2664    /// @}
2665
2666  };
2667}
2668
2669#endif
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