COIN-OR::LEMON - Graph Library

source: lemon-1.2/lemon/lgf_reader.h @ 290:f6899946c1ac

Last change on this file since 290:f6899946c1ac was 290:f6899946c1ac, checked in by Balazs Dezso <deba@…>, 11 years ago

Simplifying exceptions

  • Using asserts instead of exceptions for unitialized parameters
  • Only the IO exceptions are used in the lemon
  • DataFormatError? is renamed to FormatError?
  • The IoError? is used for file access errors
File size: 78.2 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(std::istream& is, Digraph& digraph);
396
397  template <typename Digraph>
398  DigraphReader<Digraph> digraphReader(const std::string& fn, Digraph& digraph);
399
400  template <typename Digraph>
401  DigraphReader<Digraph> digraphReader(const char *fn, Digraph& digraph);
402
403  /// \ingroup lemon_io
404  ///
405  /// \brief \ref lgf-format "LGF" reader for directed graphs
406  ///
407  /// This utility reads an \ref lgf-format "LGF" file.
408  ///
409  /// The reading method does a batch processing. The user creates a
410  /// reader object, then various reading rules can be added to the
411  /// reader, and eventually the reading is executed with the \c run()
412  /// member function. A map reading rule can be added to the reader
413  /// with the \c nodeMap() or \c arcMap() members. An optional
414  /// converter parameter can also be added as a standard functor
415  /// converting from \c std::string to the value type of the map. If it
416  /// is set, it will determine how the tokens in the file should be
417  /// converted to the value type of the map. If the functor is not set,
418  /// then a default conversion will be used. One map can be read into
419  /// multiple map objects at the same time. The \c attribute(), \c
420  /// node() and \c arc() functions are used to add attribute reading
421  /// rules.
422  ///
423  ///\code
424  /// DigraphReader<Digraph>(std::cin, digraph).
425  ///   nodeMap("coordinates", coord_map).
426  ///   arcMap("capacity", cap_map).
427  ///   node("source", src).
428  ///   node("target", trg).
429  ///   attribute("caption", caption).
430  ///   run();
431  ///\endcode
432  ///
433  /// By default the reader uses the first section in the file of the
434  /// proper type. If a section has an optional name, then it can be
435  /// selected for reading by giving an optional name parameter to the
436  /// \c nodes(), \c arcs() or \c attributes() functions.
437  ///
438  /// The \c useNodes() and \c useArcs() functions are used to tell the reader
439  /// that the nodes or arcs should not be constructed (added to the
440  /// graph) during the reading, but instead the label map of the items
441  /// are given as a parameter of these functions. An
442  /// application of these functions is multipass reading, which is
443  /// important if two \c \@arcs sections must be read from the
444  /// file. In this case the first phase would read the node set and one
445  /// of the arc sets, while the second phase would read the second arc
446  /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
447  /// The previously read label node map should be passed to the \c
448  /// useNodes() functions. Another application of multipass reading when
449  /// paths are given as a node map or an arc map.
450  /// It is impossible to read this in
451  /// a single pass, because the arcs are not constructed when the node
452  /// maps are read.
453  template <typename _Digraph>
454  class DigraphReader {
455  public:
456
457    typedef _Digraph Digraph;
458    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
459
460  private:
461
462
463    std::istream* _is;
464    bool local_is;
465    std::string _filename;
466
467    Digraph& _digraph;
468
469    std::string _nodes_caption;
470    std::string _arcs_caption;
471    std::string _attributes_caption;
472
473    typedef std::map<std::string, Node> NodeIndex;
474    NodeIndex _node_index;
475    typedef std::map<std::string, Arc> ArcIndex;
476    ArcIndex _arc_index;
477
478    typedef std::vector<std::pair<std::string,
479      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
480    NodeMaps _node_maps;
481
482    typedef std::vector<std::pair<std::string,
483      _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
484    ArcMaps _arc_maps;
485
486    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
487      Attributes;
488    Attributes _attributes;
489
490    bool _use_nodes;
491    bool _use_arcs;
492
493    bool _skip_nodes;
494    bool _skip_arcs;
495
496    int line_num;
497    std::istringstream line;
498
499  public:
500
501    /// \brief Constructor
502    ///
503    /// Construct a directed graph reader, which reads from the given
504    /// input stream.
505    DigraphReader(std::istream& is, Digraph& digraph)
506      : _is(&is), local_is(false), _digraph(digraph),
507        _use_nodes(false), _use_arcs(false),
508        _skip_nodes(false), _skip_arcs(false) {}
509
510    /// \brief Constructor
511    ///
512    /// Construct a directed graph reader, which reads from the given
513    /// file.
514    DigraphReader(const std::string& fn, Digraph& digraph)
515      : _is(new std::ifstream(fn.c_str())), local_is(true),
516        _filename(fn), _digraph(digraph),
517        _use_nodes(false), _use_arcs(false),
518        _skip_nodes(false), _skip_arcs(false) {
519      if (!(*_is)) throw IoError(fn, "Cannot open file");
520    }
521
522    /// \brief Constructor
523    ///
524    /// Construct a directed graph reader, which reads from the given
525    /// file.
526    DigraphReader(const char* fn, Digraph& digraph)
527      : _is(new std::ifstream(fn)), local_is(true),
528        _filename(fn), _digraph(digraph),
529        _use_nodes(false), _use_arcs(false),
530        _skip_nodes(false), _skip_arcs(false) {
531      if (!(*_is)) throw IoError(fn, "Cannot open file");
532    }
533
534    /// \brief Destructor
535    ~DigraphReader() {
536      for (typename NodeMaps::iterator it = _node_maps.begin();
537           it != _node_maps.end(); ++it) {
538        delete it->second;
539      }
540
541      for (typename ArcMaps::iterator it = _arc_maps.begin();
542           it != _arc_maps.end(); ++it) {
543        delete it->second;
544      }
545
546      for (typename Attributes::iterator it = _attributes.begin();
547           it != _attributes.end(); ++it) {
548        delete it->second;
549      }
550
551      if (local_is) {
552        delete _is;
553      }
554
555    }
556
557  private:
558
559    friend DigraphReader<Digraph> digraphReader<>(std::istream& is,
560                                                  Digraph& digraph);
561    friend DigraphReader<Digraph> digraphReader<>(const std::string& fn,
562                                                  Digraph& digraph);
563    friend DigraphReader<Digraph> digraphReader<>(const char *fn,
564                                                  Digraph& digraph);
565
566    DigraphReader(DigraphReader& other)
567      : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
568        _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
569        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
570
571      other._is = 0;
572      other.local_is = false;
573
574      _node_index.swap(other._node_index);
575      _arc_index.swap(other._arc_index);
576
577      _node_maps.swap(other._node_maps);
578      _arc_maps.swap(other._arc_maps);
579      _attributes.swap(other._attributes);
580
581      _nodes_caption = other._nodes_caption;
582      _arcs_caption = other._arcs_caption;
583      _attributes_caption = other._attributes_caption;
584
585    }
586
587    DigraphReader& operator=(const DigraphReader&);
588
589  public:
590
591    /// \name Reading rules
592    /// @{
593
594    /// \brief Node map reading rule
595    ///
596    /// Add a node map reading rule to the reader.
597    template <typename Map>
598    DigraphReader& nodeMap(const std::string& caption, Map& map) {
599      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
600      _reader_bits::MapStorageBase<Node>* storage =
601        new _reader_bits::MapStorage<Node, Map>(map);
602      _node_maps.push_back(std::make_pair(caption, storage));
603      return *this;
604    }
605
606    /// \brief Node map reading rule
607    ///
608    /// Add a node map reading rule with specialized converter to the
609    /// reader.
610    template <typename Map, typename Converter>
611    DigraphReader& nodeMap(const std::string& caption, Map& map,
612                           const Converter& converter = Converter()) {
613      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
614      _reader_bits::MapStorageBase<Node>* storage =
615        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
616      _node_maps.push_back(std::make_pair(caption, storage));
617      return *this;
618    }
619
620    /// \brief Arc map reading rule
621    ///
622    /// Add an arc map reading rule to the reader.
623    template <typename Map>
624    DigraphReader& arcMap(const std::string& caption, Map& map) {
625      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
626      _reader_bits::MapStorageBase<Arc>* storage =
627        new _reader_bits::MapStorage<Arc, Map>(map);
628      _arc_maps.push_back(std::make_pair(caption, storage));
629      return *this;
630    }
631
632    /// \brief Arc map reading rule
633    ///
634    /// Add an arc map reading rule with specialized converter to the
635    /// reader.
636    template <typename Map, typename Converter>
637    DigraphReader& arcMap(const std::string& caption, Map& map,
638                          const Converter& converter = Converter()) {
639      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
640      _reader_bits::MapStorageBase<Arc>* storage =
641        new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
642      _arc_maps.push_back(std::make_pair(caption, storage));
643      return *this;
644    }
645
646    /// \brief Attribute reading rule
647    ///
648    /// Add an attribute reading rule to the reader.
649    template <typename Value>
650    DigraphReader& attribute(const std::string& caption, Value& value) {
651      _reader_bits::ValueStorageBase* storage =
652        new _reader_bits::ValueStorage<Value>(value);
653      _attributes.insert(std::make_pair(caption, storage));
654      return *this;
655    }
656
657    /// \brief Attribute reading rule
658    ///
659    /// Add an attribute reading rule with specialized converter to the
660    /// reader.
661    template <typename Value, typename Converter>
662    DigraphReader& attribute(const std::string& caption, Value& value,
663                             const Converter& converter = Converter()) {
664      _reader_bits::ValueStorageBase* storage =
665        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
666      _attributes.insert(std::make_pair(caption, storage));
667      return *this;
668    }
669
670    /// \brief Node reading rule
671    ///
672    /// Add a node reading rule to reader.
673    DigraphReader& node(const std::string& caption, Node& node) {
674      typedef _reader_bits::MapLookUpConverter<Node> Converter;
675      Converter converter(_node_index);
676      _reader_bits::ValueStorageBase* storage =
677        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
678      _attributes.insert(std::make_pair(caption, storage));
679      return *this;
680    }
681
682    /// \brief Arc reading rule
683    ///
684    /// Add an arc reading rule to reader.
685    DigraphReader& arc(const std::string& caption, Arc& arc) {
686      typedef _reader_bits::MapLookUpConverter<Arc> Converter;
687      Converter converter(_arc_index);
688      _reader_bits::ValueStorageBase* storage =
689        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
690      _attributes.insert(std::make_pair(caption, storage));
691      return *this;
692    }
693
694    /// @}
695
696    /// \name Select section by name
697    /// @{
698
699    /// \brief Set \c \@nodes section to be read
700    ///
701    /// Set \c \@nodes section to be read
702    DigraphReader& nodes(const std::string& caption) {
703      _nodes_caption = caption;
704      return *this;
705    }
706
707    /// \brief Set \c \@arcs section to be read
708    ///
709    /// Set \c \@arcs section to be read
710    DigraphReader& arcs(const std::string& caption) {
711      _arcs_caption = caption;
712      return *this;
713    }
714
715    /// \brief Set \c \@attributes section to be read
716    ///
717    /// Set \c \@attributes section to be read
718    DigraphReader& attributes(const std::string& caption) {
719      _attributes_caption = caption;
720      return *this;
721    }
722
723    /// @}
724
725    /// \name Using previously constructed node or arc set
726    /// @{
727
728    /// \brief Use previously constructed node set
729    ///
730    /// Use previously constructed node set, and specify the node
731    /// label map.
732    template <typename Map>
733    DigraphReader& useNodes(const Map& map) {
734      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
735      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
736      _use_nodes = true;
737      _writer_bits::DefaultConverter<typename Map::Value> converter;
738      for (NodeIt n(_digraph); n != INVALID; ++n) {
739        _node_index.insert(std::make_pair(converter(map[n]), n));
740      }
741      return *this;
742    }
743
744    /// \brief Use previously constructed node set
745    ///
746    /// Use previously constructed node set, and specify the node
747    /// label map and a functor which converts the label map values to
748    /// \c std::string.
749    template <typename Map, typename Converter>
750    DigraphReader& useNodes(const Map& map,
751                            const Converter& converter = Converter()) {
752      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
753      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
754      _use_nodes = true;
755      for (NodeIt n(_digraph); n != INVALID; ++n) {
756        _node_index.insert(std::make_pair(converter(map[n]), n));
757      }
758      return *this;
759    }
760
761    /// \brief Use previously constructed arc set
762    ///
763    /// Use previously constructed arc set, and specify the arc
764    /// label map.
765    template <typename Map>
766    DigraphReader& useArcs(const Map& map) {
767      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
768      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
769      _use_arcs = true;
770      _writer_bits::DefaultConverter<typename Map::Value> converter;
771      for (ArcIt a(_digraph); a != INVALID; ++a) {
772        _arc_index.insert(std::make_pair(converter(map[a]), a));
773      }
774      return *this;
775    }
776
777    /// \brief Use previously constructed arc set
778    ///
779    /// Use previously constructed arc set, and specify the arc
780    /// label map and a functor which converts the label map values to
781    /// \c std::string.
782    template <typename Map, typename Converter>
783    DigraphReader& useArcs(const Map& map,
784                           const Converter& converter = Converter()) {
785      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
786      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
787      _use_arcs = true;
788      for (ArcIt a(_digraph); a != INVALID; ++a) {
789        _arc_index.insert(std::make_pair(converter(map[a]), a));
790      }
791      return *this;
792    }
793
794    /// \brief Skips the reading of node section
795    ///
796    /// Omit the reading of the node section. This implies that each node
797    /// map reading rule will be abandoned, and the nodes of the graph
798    /// will not be constructed, which usually cause that the arc set
799    /// could not be read due to lack of node name resolving.
800    /// Therefore \c skipArcs() function should also be used, or
801    /// \c useNodes() should be used to specify the label of the nodes.
802    DigraphReader& skipNodes() {
803      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
804      _skip_nodes = true;
805      return *this;
806    }
807
808    /// \brief Skips the reading of arc section
809    ///
810    /// Omit the reading of the arc section. This implies that each arc
811    /// map reading rule will be abandoned, and the arcs of the graph
812    /// will not be constructed.
813    DigraphReader& skipArcs() {
814      LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
815      _skip_arcs = true;
816      return *this;
817    }
818
819    /// @}
820
821  private:
822
823    bool readLine() {
824      std::string str;
825      while(++line_num, std::getline(*_is, str)) {
826        line.clear(); line.str(str);
827        char c;
828        if (line >> std::ws >> c && c != '#') {
829          line.putback(c);
830          return true;
831        }
832      }
833      return false;
834    }
835
836    bool readSuccess() {
837      return static_cast<bool>(*_is);
838    }
839
840    void skipSection() {
841      char c;
842      while (readSuccess() && line >> c && c != '@') {
843        readLine();
844      }
845      line.putback(c);
846    }
847
848    void readNodes() {
849
850      std::vector<int> map_index(_node_maps.size());
851      int map_num, label_index;
852
853      char c;
854      if (!readLine() || !(line >> c) || c == '@') {
855        if (readSuccess() && line) line.putback(c);
856        if (!_node_maps.empty())
857          throw FormatError("Cannot find map names");
858        return;
859      }
860      line.putback(c);
861
862      {
863        std::map<std::string, int> maps;
864
865        std::string map;
866        int index = 0;
867        while (_reader_bits::readToken(line, map)) {
868          if (maps.find(map) != maps.end()) {
869            std::ostringstream msg;
870            msg << "Multiple occurence of node map: " << map;
871            throw FormatError(msg.str());
872          }
873          maps.insert(std::make_pair(map, index));
874          ++index;
875        }
876
877        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
878          std::map<std::string, int>::iterator jt =
879            maps.find(_node_maps[i].first);
880          if (jt == maps.end()) {
881            std::ostringstream msg;
882            msg << "Map not found in file: " << _node_maps[i].first;
883            throw FormatError(msg.str());
884          }
885          map_index[i] = jt->second;
886        }
887
888        {
889          std::map<std::string, int>::iterator jt = maps.find("label");
890          if (jt != maps.end()) {
891            label_index = jt->second;
892          } else {
893            label_index = -1;
894          }
895        }
896        map_num = maps.size();
897      }
898
899      while (readLine() && line >> c && c != '@') {
900        line.putback(c);
901
902        std::vector<std::string> tokens(map_num);
903        for (int i = 0; i < map_num; ++i) {
904          if (!_reader_bits::readToken(line, tokens[i])) {
905            std::ostringstream msg;
906            msg << "Column not found (" << i + 1 << ")";
907            throw FormatError(msg.str());
908          }
909        }
910        if (line >> std::ws >> c)
911          throw FormatError("Extra character on the end of line");
912
913        Node n;
914        if (!_use_nodes) {
915          n = _digraph.addNode();
916          if (label_index != -1)
917            _node_index.insert(std::make_pair(tokens[label_index], n));
918        } else {
919          if (label_index == -1)
920            throw FormatError("Label map not found in file");
921          typename std::map<std::string, Node>::iterator it =
922            _node_index.find(tokens[label_index]);
923          if (it == _node_index.end()) {
924            std::ostringstream msg;
925            msg << "Node with label not found: " << tokens[label_index];
926            throw FormatError(msg.str());
927          }
928          n = it->second;
929        }
930
931        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
932          _node_maps[i].second->set(n, tokens[map_index[i]]);
933        }
934
935      }
936      if (readSuccess()) {
937        line.putback(c);
938      }
939    }
940
941    void readArcs() {
942
943      std::vector<int> map_index(_arc_maps.size());
944      int map_num, label_index;
945
946      char c;
947      if (!readLine() || !(line >> c) || c == '@') {
948        if (readSuccess() && line) line.putback(c);
949        if (!_arc_maps.empty())
950          throw FormatError("Cannot find map names");
951        return;
952      }
953      line.putback(c);
954
955      {
956        std::map<std::string, int> maps;
957
958        std::string map;
959        int index = 0;
960        while (_reader_bits::readToken(line, map)) {
961          if (maps.find(map) != maps.end()) {
962            std::ostringstream msg;
963            msg << "Multiple occurence of arc map: " << map;
964            throw FormatError(msg.str());
965          }
966          maps.insert(std::make_pair(map, index));
967          ++index;
968        }
969
970        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
971          std::map<std::string, int>::iterator jt =
972            maps.find(_arc_maps[i].first);
973          if (jt == maps.end()) {
974            std::ostringstream msg;
975            msg << "Map not found in file: " << _arc_maps[i].first;
976            throw FormatError(msg.str());
977          }
978          map_index[i] = jt->second;
979        }
980
981        {
982          std::map<std::string, int>::iterator jt = maps.find("label");
983          if (jt != maps.end()) {
984            label_index = jt->second;
985          } else {
986            label_index = -1;
987          }
988        }
989        map_num = maps.size();
990      }
991
992      while (readLine() && line >> c && c != '@') {
993        line.putback(c);
994
995        std::string source_token;
996        std::string target_token;
997
998        if (!_reader_bits::readToken(line, source_token))
999          throw FormatError("Source not found");
1000
1001        if (!_reader_bits::readToken(line, target_token))
1002          throw FormatError("Target not found");
1003
1004        std::vector<std::string> tokens(map_num);
1005        for (int i = 0; i < map_num; ++i) {
1006          if (!_reader_bits::readToken(line, tokens[i])) {
1007            std::ostringstream msg;
1008            msg << "Column not found (" << i + 1 << ")";
1009            throw FormatError(msg.str());
1010          }
1011        }
1012        if (line >> std::ws >> c)
1013          throw FormatError("Extra character on the end of line");
1014
1015        Arc a;
1016        if (!_use_arcs) {
1017
1018          typename NodeIndex::iterator it;
1019
1020          it = _node_index.find(source_token);
1021          if (it == _node_index.end()) {
1022            std::ostringstream msg;
1023            msg << "Item not found: " << source_token;
1024            throw FormatError(msg.str());
1025          }
1026          Node source = it->second;
1027
1028          it = _node_index.find(target_token);
1029          if (it == _node_index.end()) {
1030            std::ostringstream msg;
1031            msg << "Item not found: " << target_token;
1032            throw FormatError(msg.str());
1033          }
1034          Node target = it->second;
1035
1036          a = _digraph.addArc(source, target);
1037          if (label_index != -1)
1038            _arc_index.insert(std::make_pair(tokens[label_index], a));
1039        } else {
1040          if (label_index == -1)
1041            throw FormatError("Label map not found in file");
1042          typename std::map<std::string, Arc>::iterator it =
1043            _arc_index.find(tokens[label_index]);
1044          if (it == _arc_index.end()) {
1045            std::ostringstream msg;
1046            msg << "Arc with label not found: " << tokens[label_index];
1047            throw FormatError(msg.str());
1048          }
1049          a = it->second;
1050        }
1051
1052        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
1053          _arc_maps[i].second->set(a, tokens[map_index[i]]);
1054        }
1055
1056      }
1057      if (readSuccess()) {
1058        line.putback(c);
1059      }
1060    }
1061
1062    void readAttributes() {
1063
1064      std::set<std::string> read_attr;
1065
1066      char c;
1067      while (readLine() && line >> c && c != '@') {
1068        line.putback(c);
1069
1070        std::string attr, token;
1071        if (!_reader_bits::readToken(line, attr))
1072          throw FormatError("Attribute name not found");
1073        if (!_reader_bits::readToken(line, token))
1074          throw FormatError("Attribute value not found");
1075        if (line >> c)
1076          throw FormatError("Extra character on the end of line");
1077
1078        {
1079          std::set<std::string>::iterator it = read_attr.find(attr);
1080          if (it != read_attr.end()) {
1081            std::ostringstream msg;
1082            msg << "Multiple occurence of attribute " << attr;
1083            throw FormatError(msg.str());
1084          }
1085          read_attr.insert(attr);
1086        }
1087
1088        {
1089          typename Attributes::iterator it = _attributes.lower_bound(attr);
1090          while (it != _attributes.end() && it->first == attr) {
1091            it->second->set(token);
1092            ++it;
1093          }
1094        }
1095
1096      }
1097      if (readSuccess()) {
1098        line.putback(c);
1099      }
1100      for (typename Attributes::iterator it = _attributes.begin();
1101           it != _attributes.end(); ++it) {
1102        if (read_attr.find(it->first) == read_attr.end()) {
1103          std::ostringstream msg;
1104          msg << "Attribute not found in file: " << it->first;
1105          throw FormatError(msg.str());
1106        }
1107      }
1108    }
1109
1110  public:
1111
1112    /// \name Execution of the reader
1113    /// @{
1114
1115    /// \brief Start the batch processing
1116    ///
1117    /// This function starts the batch processing
1118    void run() {
1119      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1120      if (!*_is) {
1121        throw FormatError("Cannot find file");
1122      }
1123
1124      bool nodes_done = _skip_nodes;
1125      bool arcs_done = _skip_arcs;
1126      bool attributes_done = false;
1127
1128      line_num = 0;
1129      readLine();
1130      skipSection();
1131
1132      while (readSuccess()) {
1133        try {
1134          char c;
1135          std::string section, caption;
1136          line >> c;
1137          _reader_bits::readToken(line, section);
1138          _reader_bits::readToken(line, caption);
1139
1140          if (line >> c)
1141            throw FormatError("Extra character on the end of line");
1142
1143          if (section == "nodes" && !nodes_done) {
1144            if (_nodes_caption.empty() || _nodes_caption == caption) {
1145              readNodes();
1146              nodes_done = true;
1147            }
1148          } else if ((section == "arcs" || section == "edges") &&
1149                     !arcs_done) {
1150            if (_arcs_caption.empty() || _arcs_caption == caption) {
1151              readArcs();
1152              arcs_done = true;
1153            }
1154          } else if (section == "attributes" && !attributes_done) {
1155            if (_attributes_caption.empty() || _attributes_caption == caption) {
1156              readAttributes();
1157              attributes_done = true;
1158            }
1159          } else {
1160            readLine();
1161            skipSection();
1162          }
1163        } catch (FormatError& error) {
1164          error.line(line_num);
1165          error.file(_filename);
1166          throw;
1167        }
1168      }
1169
1170      if (!nodes_done) {
1171        throw FormatError("Section @nodes not found");
1172      }
1173
1174      if (!arcs_done) {
1175        throw FormatError("Section @arcs not found");
1176      }
1177
1178      if (!attributes_done && !_attributes.empty()) {
1179        throw FormatError("Section @attributes not found");
1180      }
1181
1182    }
1183
1184    /// @}
1185
1186  };
1187
1188  /// \brief Return a \ref DigraphReader class
1189  ///
1190  /// This function just returns a \ref DigraphReader class.
1191  /// \relates DigraphReader
1192  template <typename Digraph>
1193  DigraphReader<Digraph> digraphReader(std::istream& is, Digraph& digraph) {
1194    DigraphReader<Digraph> tmp(is, 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 std::string& fn,
1204                                       Digraph& digraph) {
1205    DigraphReader<Digraph> tmp(fn, digraph);
1206    return tmp;
1207  }
1208
1209  /// \brief Return a \ref DigraphReader class
1210  ///
1211  /// This function just returns a \ref DigraphReader class.
1212  /// \relates DigraphReader
1213  template <typename Digraph>
1214  DigraphReader<Digraph> digraphReader(const char* fn, Digraph& digraph) {
1215    DigraphReader<Digraph> tmp(fn, digraph);
1216    return tmp;
1217  }
1218
1219  template <typename Graph>
1220  class GraphReader;
1221
1222  template <typename Graph>
1223  GraphReader<Graph> graphReader(std::istream& is, Graph& graph);
1224
1225  template <typename Graph>
1226  GraphReader<Graph> graphReader(const std::string& fn, Graph& graph);
1227
1228  template <typename Graph>
1229  GraphReader<Graph> graphReader(const char *fn, Graph& graph);
1230
1231  /// \ingroup lemon_io
1232  ///
1233  /// \brief \ref lgf-format "LGF" reader for undirected graphs
1234  ///
1235  /// This utility reads an \ref lgf-format "LGF" file.
1236  ///
1237  /// It can be used almost the same way as \c DigraphReader.
1238  /// The only difference is that this class can handle edges and
1239  /// edge maps as well as arcs and arc maps.
1240  ///
1241  /// The columns in the \c \@edges (or \c \@arcs) section are the
1242  /// edge maps. However, if there are two maps with the same name
1243  /// prefixed with \c '+' and \c '-', then these can be read into an
1244  /// arc map.  Similarly, an attribute can be read into an arc, if
1245  /// it's value is an edge label prefixed with \c '+' or \c '-'.
1246  template <typename _Graph>
1247  class GraphReader {
1248  public:
1249
1250    typedef _Graph Graph;
1251    TEMPLATE_GRAPH_TYPEDEFS(Graph);
1252
1253  private:
1254
1255    std::istream* _is;
1256    bool local_is;
1257    std::string _filename;
1258
1259    Graph& _graph;
1260
1261    std::string _nodes_caption;
1262    std::string _edges_caption;
1263    std::string _attributes_caption;
1264
1265    typedef std::map<std::string, Node> NodeIndex;
1266    NodeIndex _node_index;
1267    typedef std::map<std::string, Edge> EdgeIndex;
1268    EdgeIndex _edge_index;
1269
1270    typedef std::vector<std::pair<std::string,
1271      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
1272    NodeMaps _node_maps;
1273
1274    typedef std::vector<std::pair<std::string,
1275      _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
1276    EdgeMaps _edge_maps;
1277
1278    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
1279      Attributes;
1280    Attributes _attributes;
1281
1282    bool _use_nodes;
1283    bool _use_edges;
1284
1285    bool _skip_nodes;
1286    bool _skip_edges;
1287
1288    int line_num;
1289    std::istringstream line;
1290
1291  public:
1292
1293    /// \brief Constructor
1294    ///
1295    /// Construct an undirected graph reader, which reads from the given
1296    /// input stream.
1297    GraphReader(std::istream& is, Graph& graph)
1298      : _is(&is), local_is(false), _graph(graph),
1299        _use_nodes(false), _use_edges(false),
1300        _skip_nodes(false), _skip_edges(false) {}
1301
1302    /// \brief Constructor
1303    ///
1304    /// Construct an undirected graph reader, which reads from the given
1305    /// file.
1306    GraphReader(const std::string& fn, Graph& graph)
1307      : _is(new std::ifstream(fn.c_str())), local_is(true),
1308        _filename(fn), _graph(graph),
1309        _use_nodes(false), _use_edges(false),
1310        _skip_nodes(false), _skip_edges(false) {
1311      if (!(*_is)) throw IoError(fn, "Cannot open file");
1312    }
1313
1314    /// \brief Constructor
1315    ///
1316    /// Construct an undirected graph reader, which reads from the given
1317    /// file.
1318    GraphReader(const char* fn, Graph& graph)
1319      : _is(new std::ifstream(fn)), local_is(true),
1320        _filename(fn), _graph(graph),
1321        _use_nodes(false), _use_edges(false),
1322        _skip_nodes(false), _skip_edges(false) {
1323      if (!(*_is)) throw IoError(fn, "Cannot open file");
1324    }
1325
1326    /// \brief Destructor
1327    ~GraphReader() {
1328      for (typename NodeMaps::iterator it = _node_maps.begin();
1329           it != _node_maps.end(); ++it) {
1330        delete it->second;
1331      }
1332
1333      for (typename EdgeMaps::iterator it = _edge_maps.begin();
1334           it != _edge_maps.end(); ++it) {
1335        delete it->second;
1336      }
1337
1338      for (typename Attributes::iterator it = _attributes.begin();
1339           it != _attributes.end(); ++it) {
1340        delete it->second;
1341      }
1342
1343      if (local_is) {
1344        delete _is;
1345      }
1346
1347    }
1348
1349  private:
1350    friend GraphReader<Graph> graphReader<>(std::istream& is, Graph& graph);
1351    friend GraphReader<Graph> graphReader<>(const std::string& fn,
1352                                            Graph& graph);
1353    friend GraphReader<Graph> graphReader<>(const char *fn, Graph& graph);
1354
1355    GraphReader(GraphReader& other)
1356      : _is(other._is), local_is(other.local_is), _graph(other._graph),
1357        _use_nodes(other._use_nodes), _use_edges(other._use_edges),
1358        _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
1359
1360      other._is = 0;
1361      other.local_is = false;
1362
1363      _node_index.swap(other._node_index);
1364      _edge_index.swap(other._edge_index);
1365
1366      _node_maps.swap(other._node_maps);
1367      _edge_maps.swap(other._edge_maps);
1368      _attributes.swap(other._attributes);
1369
1370      _nodes_caption = other._nodes_caption;
1371      _edges_caption = other._edges_caption;
1372      _attributes_caption = other._attributes_caption;
1373
1374    }
1375
1376    GraphReader& operator=(const GraphReader&);
1377
1378  public:
1379
1380    /// \name Reading rules
1381    /// @{
1382
1383    /// \brief Node map reading rule
1384    ///
1385    /// Add a node map reading rule to the reader.
1386    template <typename Map>
1387    GraphReader& nodeMap(const std::string& caption, Map& map) {
1388      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1389      _reader_bits::MapStorageBase<Node>* storage =
1390        new _reader_bits::MapStorage<Node, Map>(map);
1391      _node_maps.push_back(std::make_pair(caption, storage));
1392      return *this;
1393    }
1394
1395    /// \brief Node map reading rule
1396    ///
1397    /// Add a node map reading rule with specialized converter to the
1398    /// reader.
1399    template <typename Map, typename Converter>
1400    GraphReader& nodeMap(const std::string& caption, Map& map,
1401                           const Converter& converter = Converter()) {
1402      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1403      _reader_bits::MapStorageBase<Node>* storage =
1404        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
1405      _node_maps.push_back(std::make_pair(caption, storage));
1406      return *this;
1407    }
1408
1409    /// \brief Edge map reading rule
1410    ///
1411    /// Add an edge map reading rule to the reader.
1412    template <typename Map>
1413    GraphReader& edgeMap(const std::string& caption, Map& map) {
1414      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1415      _reader_bits::MapStorageBase<Edge>* storage =
1416        new _reader_bits::MapStorage<Edge, Map>(map);
1417      _edge_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 with specialized converter to the
1424    /// reader.
1425    template <typename Map, typename Converter>
1426    GraphReader& edgeMap(const std::string& caption, Map& map,
1427                          const Converter& converter = Converter()) {
1428      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1429      _reader_bits::MapStorageBase<Edge>* storage =
1430        new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
1431      _edge_maps.push_back(std::make_pair(caption, storage));
1432      return *this;
1433    }
1434
1435    /// \brief Arc map reading rule
1436    ///
1437    /// Add an arc map reading rule to the reader.
1438    template <typename Map>
1439    GraphReader& arcMap(const std::string& caption, Map& map) {
1440      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1441      _reader_bits::MapStorageBase<Edge>* forward_storage =
1442        new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
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>(_graph, map);
1446      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1447      return *this;
1448    }
1449
1450    /// \brief Arc map reading rule
1451    ///
1452    /// Add an arc map reading rule with specialized converter to the
1453    /// reader.
1454    template <typename Map, typename Converter>
1455    GraphReader& arcMap(const std::string& caption, Map& map,
1456                          const Converter& converter = Converter()) {
1457      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1458      _reader_bits::MapStorageBase<Edge>* forward_storage =
1459        new _reader_bits::GraphArcMapStorage<Graph, true, Map, Converter>
1460        (_graph, map, converter);
1461      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1462      _reader_bits::MapStorageBase<Edge>* backward_storage =
1463        new _reader_bits::GraphArcMapStorage<Graph, false, Map, Converter>
1464        (_graph, map, converter);
1465      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1466      return *this;
1467    }
1468
1469    /// \brief Attribute reading rule
1470    ///
1471    /// Add an attribute reading rule to the reader.
1472    template <typename Value>
1473    GraphReader& attribute(const std::string& caption, Value& value) {
1474      _reader_bits::ValueStorageBase* storage =
1475        new _reader_bits::ValueStorage<Value>(value);
1476      _attributes.insert(std::make_pair(caption, storage));
1477      return *this;
1478    }
1479
1480    /// \brief Attribute reading rule
1481    ///
1482    /// Add an attribute reading rule with specialized converter to the
1483    /// reader.
1484    template <typename Value, typename Converter>
1485    GraphReader& attribute(const std::string& caption, Value& value,
1486                             const Converter& converter = Converter()) {
1487      _reader_bits::ValueStorageBase* storage =
1488        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
1489      _attributes.insert(std::make_pair(caption, storage));
1490      return *this;
1491    }
1492
1493    /// \brief Node reading rule
1494    ///
1495    /// Add a node reading rule to reader.
1496    GraphReader& node(const std::string& caption, Node& node) {
1497      typedef _reader_bits::MapLookUpConverter<Node> Converter;
1498      Converter converter(_node_index);
1499      _reader_bits::ValueStorageBase* storage =
1500        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
1501      _attributes.insert(std::make_pair(caption, storage));
1502      return *this;
1503    }
1504
1505    /// \brief Edge reading rule
1506    ///
1507    /// Add an edge reading rule to reader.
1508    GraphReader& edge(const std::string& caption, Edge& edge) {
1509      typedef _reader_bits::MapLookUpConverter<Edge> Converter;
1510      Converter converter(_edge_index);
1511      _reader_bits::ValueStorageBase* storage =
1512        new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
1513      _attributes.insert(std::make_pair(caption, storage));
1514      return *this;
1515    }
1516
1517    /// \brief Arc reading rule
1518    ///
1519    /// Add an arc reading rule to reader.
1520    GraphReader& arc(const std::string& caption, Arc& arc) {
1521      typedef _reader_bits::GraphArcLookUpConverter<Graph> Converter;
1522      Converter converter(_graph, _edge_index);
1523      _reader_bits::ValueStorageBase* storage =
1524        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
1525      _attributes.insert(std::make_pair(caption, storage));
1526      return *this;
1527    }
1528
1529    /// @}
1530
1531    /// \name Select section by name
1532    /// @{
1533
1534    /// \brief Set \c \@nodes section to be read
1535    ///
1536    /// Set \c \@nodes section to be read.
1537    GraphReader& nodes(const std::string& caption) {
1538      _nodes_caption = caption;
1539      return *this;
1540    }
1541
1542    /// \brief Set \c \@edges section to be read
1543    ///
1544    /// Set \c \@edges section to be read.
1545    GraphReader& edges(const std::string& caption) {
1546      _edges_caption = caption;
1547      return *this;
1548    }
1549
1550    /// \brief Set \c \@attributes section to be read
1551    ///
1552    /// Set \c \@attributes section to be read.
1553    GraphReader& attributes(const std::string& caption) {
1554      _attributes_caption = caption;
1555      return *this;
1556    }
1557
1558    /// @}
1559
1560    /// \name Using previously constructed node or edge set
1561    /// @{
1562
1563    /// \brief Use previously constructed node set
1564    ///
1565    /// Use previously constructed node set, and specify the node
1566    /// label map.
1567    template <typename Map>
1568    GraphReader& useNodes(const Map& map) {
1569      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1570      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1571      _use_nodes = true;
1572      _writer_bits::DefaultConverter<typename Map::Value> converter;
1573      for (NodeIt n(_graph); n != INVALID; ++n) {
1574        _node_index.insert(std::make_pair(converter(map[n]), n));
1575      }
1576      return *this;
1577    }
1578
1579    /// \brief Use previously constructed node set
1580    ///
1581    /// Use previously constructed node set, and specify the node
1582    /// label map and a functor which converts the label map values to
1583    /// \c std::string.
1584    template <typename Map, typename Converter>
1585    GraphReader& useNodes(const Map& map,
1586                            const Converter& converter = Converter()) {
1587      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1588      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1589      _use_nodes = true;
1590      for (NodeIt n(_graph); n != INVALID; ++n) {
1591        _node_index.insert(std::make_pair(converter(map[n]), n));
1592      }
1593      return *this;
1594    }
1595
1596    /// \brief Use previously constructed edge set
1597    ///
1598    /// Use previously constructed edge set, and specify the edge
1599    /// label map.
1600    template <typename Map>
1601    GraphReader& useEdges(const Map& map) {
1602      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1603      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1604      _use_edges = true;
1605      _writer_bits::DefaultConverter<typename Map::Value> converter;
1606      for (EdgeIt a(_graph); a != INVALID; ++a) {
1607        _edge_index.insert(std::make_pair(converter(map[a]), a));
1608      }
1609      return *this;
1610    }
1611
1612    /// \brief Use previously constructed edge set
1613    ///
1614    /// Use previously constructed edge set, and specify the edge
1615    /// label map and a functor which converts the label map values to
1616    /// \c std::string.
1617    template <typename Map, typename Converter>
1618    GraphReader& useEdges(const Map& map,
1619                            const Converter& converter = Converter()) {
1620      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1621      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1622      _use_edges = true;
1623      for (EdgeIt a(_graph); a != INVALID; ++a) {
1624        _edge_index.insert(std::make_pair(converter(map[a]), a));
1625      }
1626      return *this;
1627    }
1628
1629    /// \brief Skip the reading of node section
1630    ///
1631    /// Omit the reading of the node section. This implies that each node
1632    /// map reading rule will be abandoned, and the nodes of the graph
1633    /// will not be constructed, which usually cause that the edge set
1634    /// could not be read due to lack of node name
1635    /// could not be read due to lack of node name resolving.
1636    /// Therefore \c skipEdges() function should also be used, or
1637    /// \c useNodes() should be used to specify the label of the nodes.
1638    GraphReader& skipNodes() {
1639      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
1640      _skip_nodes = true;
1641      return *this;
1642    }
1643
1644    /// \brief Skip the reading of edge section
1645    ///
1646    /// Omit the reading of the edge section. This implies that each edge
1647    /// map reading rule will be abandoned, and the edges of the graph
1648    /// will not be constructed.
1649    GraphReader& skipEdges() {
1650      LEMON_ASSERT(!_skip_edges, "Skip edges already set");
1651      _skip_edges = true;
1652      return *this;
1653    }
1654
1655    /// @}
1656
1657  private:
1658
1659    bool readLine() {
1660      std::string str;
1661      while(++line_num, std::getline(*_is, str)) {
1662        line.clear(); line.str(str);
1663        char c;
1664        if (line >> std::ws >> c && c != '#') {
1665          line.putback(c);
1666          return true;
1667        }
1668      }
1669      return false;
1670    }
1671
1672    bool readSuccess() {
1673      return static_cast<bool>(*_is);
1674    }
1675
1676    void skipSection() {
1677      char c;
1678      while (readSuccess() && line >> c && c != '@') {
1679        readLine();
1680      }
1681      line.putback(c);
1682    }
1683
1684    void readNodes() {
1685
1686      std::vector<int> map_index(_node_maps.size());
1687      int map_num, label_index;
1688
1689      char c;
1690      if (!readLine() || !(line >> c) || c == '@') {
1691        if (readSuccess() && line) line.putback(c);
1692        if (!_node_maps.empty())
1693          throw FormatError("Cannot find map names");
1694        return;
1695      }
1696      line.putback(c);
1697
1698      {
1699        std::map<std::string, int> maps;
1700
1701        std::string map;
1702        int index = 0;
1703        while (_reader_bits::readToken(line, map)) {
1704          if (maps.find(map) != maps.end()) {
1705            std::ostringstream msg;
1706            msg << "Multiple occurence of node map: " << map;
1707            throw FormatError(msg.str());
1708          }
1709          maps.insert(std::make_pair(map, index));
1710          ++index;
1711        }
1712
1713        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1714          std::map<std::string, int>::iterator jt =
1715            maps.find(_node_maps[i].first);
1716          if (jt == maps.end()) {
1717            std::ostringstream msg;
1718            msg << "Map not found in file: " << _node_maps[i].first;
1719            throw FormatError(msg.str());
1720          }
1721          map_index[i] = jt->second;
1722        }
1723
1724        {
1725          std::map<std::string, int>::iterator jt = maps.find("label");
1726          if (jt != maps.end()) {
1727            label_index = jt->second;
1728          } else {
1729            label_index = -1;
1730          }
1731        }
1732        map_num = maps.size();
1733      }
1734
1735      while (readLine() && line >> c && c != '@') {
1736        line.putback(c);
1737
1738        std::vector<std::string> tokens(map_num);
1739        for (int i = 0; i < map_num; ++i) {
1740          if (!_reader_bits::readToken(line, tokens[i])) {
1741            std::ostringstream msg;
1742            msg << "Column not found (" << i + 1 << ")";
1743            throw FormatError(msg.str());
1744          }
1745        }
1746        if (line >> std::ws >> c)
1747          throw FormatError("Extra character on the end of line");
1748
1749        Node n;
1750        if (!_use_nodes) {
1751          n = _graph.addNode();
1752          if (label_index != -1)
1753            _node_index.insert(std::make_pair(tokens[label_index], n));
1754        } else {
1755          if (label_index == -1)
1756            throw FormatError("Label map not found in file");
1757          typename std::map<std::string, Node>::iterator it =
1758            _node_index.find(tokens[label_index]);
1759          if (it == _node_index.end()) {
1760            std::ostringstream msg;
1761            msg << "Node with label not found: " << tokens[label_index];
1762            throw FormatError(msg.str());
1763          }
1764          n = it->second;
1765        }
1766
1767        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1768          _node_maps[i].second->set(n, tokens[map_index[i]]);
1769        }
1770
1771      }
1772      if (readSuccess()) {
1773        line.putback(c);
1774      }
1775    }
1776
1777    void readEdges() {
1778
1779      std::vector<int> map_index(_edge_maps.size());
1780      int map_num, label_index;
1781
1782      char c;
1783      if (!readLine() || !(line >> c) || c == '@') {
1784        if (readSuccess() && line) line.putback(c);
1785        if (!_edge_maps.empty())
1786          throw FormatError("Cannot find map names");
1787        return;
1788      }
1789      line.putback(c);
1790
1791      {
1792        std::map<std::string, int> maps;
1793
1794        std::string map;
1795        int index = 0;
1796        while (_reader_bits::readToken(line, map)) {
1797          if (maps.find(map) != maps.end()) {
1798            std::ostringstream msg;
1799            msg << "Multiple occurence of edge map: " << map;
1800            throw FormatError(msg.str());
1801          }
1802          maps.insert(std::make_pair(map, index));
1803          ++index;
1804        }
1805
1806        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1807          std::map<std::string, int>::iterator jt =
1808            maps.find(_edge_maps[i].first);
1809          if (jt == maps.end()) {
1810            std::ostringstream msg;
1811            msg << "Map not found in file: " << _edge_maps[i].first;
1812            throw FormatError(msg.str());
1813          }
1814          map_index[i] = jt->second;
1815        }
1816
1817        {
1818          std::map<std::string, int>::iterator jt = maps.find("label");
1819          if (jt != maps.end()) {
1820            label_index = jt->second;
1821          } else {
1822            label_index = -1;
1823          }
1824        }
1825        map_num = maps.size();
1826      }
1827
1828      while (readLine() && line >> c && c != '@') {
1829        line.putback(c);
1830
1831        std::string source_token;
1832        std::string target_token;
1833
1834        if (!_reader_bits::readToken(line, source_token))
1835          throw FormatError("Node u not found");
1836
1837        if (!_reader_bits::readToken(line, target_token))
1838          throw FormatError("Node v not found");
1839
1840        std::vector<std::string> tokens(map_num);
1841        for (int i = 0; i < map_num; ++i) {
1842          if (!_reader_bits::readToken(line, tokens[i])) {
1843            std::ostringstream msg;
1844            msg << "Column not found (" << i + 1 << ")";
1845            throw FormatError(msg.str());
1846          }
1847        }
1848        if (line >> std::ws >> c)
1849          throw FormatError("Extra character on the end of line");
1850
1851        Edge e;
1852        if (!_use_edges) {
1853
1854          typename NodeIndex::iterator it;
1855
1856          it = _node_index.find(source_token);
1857          if (it == _node_index.end()) {
1858            std::ostringstream msg;
1859            msg << "Item not found: " << source_token;
1860            throw FormatError(msg.str());
1861          }
1862          Node source = it->second;
1863
1864          it = _node_index.find(target_token);
1865          if (it == _node_index.end()) {
1866            std::ostringstream msg;
1867            msg << "Item not found: " << target_token;
1868            throw FormatError(msg.str());
1869          }
1870          Node target = it->second;
1871
1872          e = _graph.addEdge(source, target);
1873          if (label_index != -1)
1874            _edge_index.insert(std::make_pair(tokens[label_index], e));
1875        } else {
1876          if (label_index == -1)
1877            throw FormatError("Label map not found in file");
1878          typename std::map<std::string, Edge>::iterator it =
1879            _edge_index.find(tokens[label_index]);
1880          if (it == _edge_index.end()) {
1881            std::ostringstream msg;
1882            msg << "Edge with label not found: " << tokens[label_index];
1883            throw FormatError(msg.str());
1884          }
1885          e = it->second;
1886        }
1887
1888        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1889          _edge_maps[i].second->set(e, tokens[map_index[i]]);
1890        }
1891
1892      }
1893      if (readSuccess()) {
1894        line.putback(c);
1895      }
1896    }
1897
1898    void readAttributes() {
1899
1900      std::set<std::string> read_attr;
1901
1902      char c;
1903      while (readLine() && line >> c && c != '@') {
1904        line.putback(c);
1905
1906        std::string attr, token;
1907        if (!_reader_bits::readToken(line, attr))
1908          throw FormatError("Attribute name not found");
1909        if (!_reader_bits::readToken(line, token))
1910          throw FormatError("Attribute value not found");
1911        if (line >> c)
1912          throw FormatError("Extra character on the end of line");
1913
1914        {
1915          std::set<std::string>::iterator it = read_attr.find(attr);
1916          if (it != read_attr.end()) {
1917            std::ostringstream msg;
1918            msg << "Multiple occurence of attribute " << attr;
1919            throw FormatError(msg.str());
1920          }
1921          read_attr.insert(attr);
1922        }
1923
1924        {
1925          typename Attributes::iterator it = _attributes.lower_bound(attr);
1926          while (it != _attributes.end() && it->first == attr) {
1927            it->second->set(token);
1928            ++it;
1929          }
1930        }
1931
1932      }
1933      if (readSuccess()) {
1934        line.putback(c);
1935      }
1936      for (typename Attributes::iterator it = _attributes.begin();
1937           it != _attributes.end(); ++it) {
1938        if (read_attr.find(it->first) == read_attr.end()) {
1939          std::ostringstream msg;
1940          msg << "Attribute not found in file: " << it->first;
1941          throw FormatError(msg.str());
1942        }
1943      }
1944    }
1945
1946  public:
1947
1948    /// \name Execution of the reader
1949    /// @{
1950
1951    /// \brief Start the batch processing
1952    ///
1953    /// This function starts the batch processing
1954    void run() {
1955
1956      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1957
1958      bool nodes_done = _skip_nodes;
1959      bool edges_done = _skip_edges;
1960      bool attributes_done = false;
1961
1962      line_num = 0;
1963      readLine();
1964      skipSection();
1965
1966      while (readSuccess()) {
1967        try {
1968          char c;
1969          std::string section, caption;
1970          line >> c;
1971          _reader_bits::readToken(line, section);
1972          _reader_bits::readToken(line, caption);
1973
1974          if (line >> c)
1975            throw FormatError("Extra character on the end of line");
1976
1977          if (section == "nodes" && !nodes_done) {
1978            if (_nodes_caption.empty() || _nodes_caption == caption) {
1979              readNodes();
1980              nodes_done = true;
1981            }
1982          } else if ((section == "edges" || section == "arcs") &&
1983                     !edges_done) {
1984            if (_edges_caption.empty() || _edges_caption == caption) {
1985              readEdges();
1986              edges_done = true;
1987            }
1988          } else if (section == "attributes" && !attributes_done) {
1989            if (_attributes_caption.empty() || _attributes_caption == caption) {
1990              readAttributes();
1991              attributes_done = true;
1992            }
1993          } else {
1994            readLine();
1995            skipSection();
1996          }
1997        } catch (FormatError& error) {
1998          error.line(line_num);
1999          error.file(_filename);
2000          throw;
2001        }
2002      }
2003
2004      if (!nodes_done) {
2005        throw FormatError("Section @nodes not found");
2006      }
2007
2008      if (!edges_done) {
2009        throw FormatError("Section @edges not found");
2010      }
2011
2012      if (!attributes_done && !_attributes.empty()) {
2013        throw FormatError("Section @attributes not found");
2014      }
2015
2016    }
2017
2018    /// @}
2019
2020  };
2021
2022  /// \brief Return a \ref GraphReader class
2023  ///
2024  /// This function just returns a \ref GraphReader class.
2025  /// \relates GraphReader
2026  template <typename Graph>
2027  GraphReader<Graph> graphReader(std::istream& is, Graph& graph) {
2028    GraphReader<Graph> tmp(is, graph);
2029    return tmp;
2030  }
2031
2032  /// \brief Return a \ref GraphReader class
2033  ///
2034  /// This function just returns a \ref GraphReader class.
2035  /// \relates GraphReader
2036  template <typename Graph>
2037  GraphReader<Graph> graphReader(const std::string& fn,
2038                                       Graph& graph) {
2039    GraphReader<Graph> tmp(fn, graph);
2040    return tmp;
2041  }
2042
2043  /// \brief Return a \ref GraphReader class
2044  ///
2045  /// This function just returns a \ref GraphReader class.
2046  /// \relates GraphReader
2047  template <typename Graph>
2048  GraphReader<Graph> graphReader(const char* fn, Graph& graph) {
2049    GraphReader<Graph> tmp(fn, graph);
2050    return tmp;
2051  }
2052
2053  class SectionReader;
2054
2055  SectionReader sectionReader(std::istream& is);
2056  SectionReader sectionReader(const std::string& fn);
2057  SectionReader sectionReader(const char* fn);
2058
2059  /// \ingroup lemon_io
2060  ///
2061  /// \brief Section reader class
2062  ///
2063  /// In the \ref lgf-format "LGF" file extra sections can be placed,
2064  /// which contain any data in arbitrary format. Such sections can be
2065  /// read with this class. A reading rule can be added to the class
2066  /// with two different functions. With the \c sectionLines() function a
2067  /// functor can process the section line-by-line, while with the \c
2068  /// sectionStream() member the section can be read from an input
2069  /// stream.
2070  class SectionReader {
2071  private:
2072
2073    std::istream* _is;
2074    bool local_is;
2075    std::string _filename;
2076
2077    typedef std::map<std::string, _reader_bits::Section*> Sections;
2078    Sections _sections;
2079
2080    int line_num;
2081    std::istringstream line;
2082
2083  public:
2084
2085    /// \brief Constructor
2086    ///
2087    /// Construct a section reader, which reads from the given input
2088    /// stream.
2089    SectionReader(std::istream& is)
2090      : _is(&is), local_is(false) {}
2091
2092    /// \brief Constructor
2093    ///
2094    /// Construct a section reader, which reads from the given file.
2095    SectionReader(const std::string& fn)
2096      : _is(new std::ifstream(fn.c_str())), local_is(true),
2097        _filename(fn) {
2098      if (!(*_is)) throw IoError(fn, "Cannot open file");
2099    }
2100
2101    /// \brief Constructor
2102    ///
2103    /// Construct a section reader, which reads from the given file.
2104    SectionReader(const char* fn)
2105      : _is(new std::ifstream(fn)), local_is(true),
2106        _filename(fn) {
2107      if (!(*_is)) throw IoError(fn, "Cannot open file");
2108    }
2109
2110    /// \brief Destructor
2111    ~SectionReader() {
2112      for (Sections::iterator it = _sections.begin();
2113           it != _sections.end(); ++it) {
2114        delete it->second;
2115      }
2116
2117      if (local_is) {
2118        delete _is;
2119      }
2120
2121    }
2122
2123  private:
2124
2125    friend SectionReader sectionReader(std::istream& is);
2126    friend SectionReader sectionReader(const std::string& fn);
2127    friend SectionReader sectionReader(const char* fn);
2128
2129    SectionReader(SectionReader& other)
2130      : _is(other._is), local_is(other.local_is) {
2131
2132      other._is = 0;
2133      other.local_is = false;
2134
2135      _sections.swap(other._sections);
2136    }
2137
2138    SectionReader& operator=(const SectionReader&);
2139
2140  public:
2141
2142    /// \name Section readers
2143    /// @{
2144
2145    /// \brief Add a section processor with line oriented reading
2146    ///
2147    /// The first parameter is the type descriptor of the section, the
2148    /// second is a functor, which takes just one \c std::string
2149    /// parameter. At the reading process, each line of the section
2150    /// will be given to the functor object. However, the empty lines
2151    /// and the comment lines are filtered out, and the leading
2152    /// whitespaces are trimmed from each processed string.
2153    ///
2154    /// For example let's see a section, which contain several
2155    /// integers, which should be inserted into a vector.
2156    ///\code
2157    ///  @numbers
2158    ///  12 45 23
2159    ///  4
2160    ///  23 6
2161    ///\endcode
2162    ///
2163    /// The functor is implemented as a struct:
2164    ///\code
2165    ///  struct NumberSection {
2166    ///    std::vector<int>& _data;
2167    ///    NumberSection(std::vector<int>& data) : _data(data) {}
2168    ///    void operator()(const std::string& line) {
2169    ///      std::istringstream ls(line);
2170    ///      int value;
2171    ///      while (ls >> value) _data.push_back(value);
2172    ///    }
2173    ///  };
2174    ///
2175    ///  // ...
2176    ///
2177    ///  reader.sectionLines("numbers", NumberSection(vec));
2178    ///\endcode
2179    template <typename Functor>
2180    SectionReader& sectionLines(const std::string& type, Functor functor) {
2181      LEMON_ASSERT(!type.empty(), "Type is empty.");
2182      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2183                   "Multiple reading of section.");
2184      _sections.insert(std::make_pair(type,
2185        new _reader_bits::LineSection<Functor>(functor)));
2186      return *this;
2187    }
2188
2189
2190    /// \brief Add a section processor with stream oriented reading
2191    ///
2192    /// The first parameter is the type of the section, the second is
2193    /// a functor, which takes an \c std::istream& and an \c int&
2194    /// parameter, the latter regard to the line number of stream. The
2195    /// functor can read the input while the section go on, and the
2196    /// line number should be modified accordingly.
2197    template <typename Functor>
2198    SectionReader& sectionStream(const std::string& type, Functor functor) {
2199      LEMON_ASSERT(!type.empty(), "Type is empty.");
2200      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2201                   "Multiple reading of section.");
2202      _sections.insert(std::make_pair(type,
2203         new _reader_bits::StreamSection<Functor>(functor)));
2204      return *this;
2205    }
2206
2207    /// @}
2208
2209  private:
2210
2211    bool readLine() {
2212      std::string str;
2213      while(++line_num, std::getline(*_is, str)) {
2214        line.clear(); line.str(str);
2215        char c;
2216        if (line >> std::ws >> c && c != '#') {
2217          line.putback(c);
2218          return true;
2219        }
2220      }
2221      return false;
2222    }
2223
2224    bool readSuccess() {
2225      return static_cast<bool>(*_is);
2226    }
2227
2228    void skipSection() {
2229      char c;
2230      while (readSuccess() && line >> c && c != '@') {
2231        readLine();
2232      }
2233      line.putback(c);
2234    }
2235
2236  public:
2237
2238
2239    /// \name Execution of the reader
2240    /// @{
2241
2242    /// \brief Start the batch processing
2243    ///
2244    /// This function starts the batch processing.
2245    void run() {
2246
2247      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
2248
2249      std::set<std::string> extra_sections;
2250
2251      line_num = 0;
2252      readLine();
2253      skipSection();
2254
2255      while (readSuccess()) {
2256        try {
2257          char c;
2258          std::string section, caption;
2259          line >> c;
2260          _reader_bits::readToken(line, section);
2261          _reader_bits::readToken(line, caption);
2262
2263          if (line >> c)
2264            throw FormatError("Extra character on the end of line");
2265
2266          if (extra_sections.find(section) != extra_sections.end()) {
2267            std::ostringstream msg;
2268            msg << "Multiple occurence of section " << section;
2269            throw FormatError(msg.str());
2270          }
2271          Sections::iterator it = _sections.find(section);
2272          if (it != _sections.end()) {
2273            extra_sections.insert(section);
2274            it->second->process(*_is, line_num);
2275          }
2276          readLine();
2277          skipSection();
2278        } catch (FormatError& error) {
2279          error.line(line_num);
2280          error.file(_filename);
2281          throw;
2282        }
2283      }
2284      for (Sections::iterator it = _sections.begin();
2285           it != _sections.end(); ++it) {
2286        if (extra_sections.find(it->first) == extra_sections.end()) {
2287          std::ostringstream os;
2288          os << "Cannot find section: " << it->first;
2289          throw FormatError(os.str());
2290        }
2291      }
2292    }
2293
2294    /// @}
2295
2296  };
2297
2298  /// \brief Return a \ref SectionReader class
2299  ///
2300  /// This function just returns a \ref SectionReader class.
2301  /// \relates SectionReader
2302  inline SectionReader sectionReader(std::istream& is) {
2303    SectionReader tmp(is);
2304    return tmp;
2305  }
2306
2307  /// \brief Return a \ref SectionReader class
2308  ///
2309  /// This function just returns a \ref SectionReader class.
2310  /// \relates SectionReader
2311  inline SectionReader sectionReader(const std::string& fn) {
2312    SectionReader tmp(fn);
2313    return tmp;
2314  }
2315
2316  /// \brief Return a \ref SectionReader class
2317  ///
2318  /// This function just returns a \ref SectionReader class.
2319  /// \relates SectionReader
2320  inline SectionReader sectionReader(const char* fn) {
2321    SectionReader tmp(fn);
2322    return tmp;
2323  }
2324
2325  /// \ingroup lemon_io
2326  ///
2327  /// \brief Reader for the contents of the \ref lgf-format "LGF" file
2328  ///
2329  /// This class can be used to read the sections, the map names and
2330  /// the attributes from a file. Usually, the LEMON programs know
2331  /// that, which type of graph, which maps and which attributes
2332  /// should be read from a file, but in general tools (like glemon)
2333  /// the contents of an LGF file should be guessed somehow. This class
2334  /// reads the graph and stores the appropriate information for
2335  /// reading the graph.
2336  ///
2337  ///\code
2338  /// LgfContents contents("graph.lgf");
2339  /// contents.run();
2340  ///
2341  /// // Does it contain any node section and arc section?
2342  /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
2343  ///   std::cerr << "Failure, cannot find graph." << std::endl;
2344  ///   return -1;
2345  /// }
2346  /// std::cout << "The name of the default node section: "
2347  ///           << contents.nodeSection(0) << std::endl;
2348  /// std::cout << "The number of the arc maps: "
2349  ///           << contents.arcMaps(0).size() << std::endl;
2350  /// std::cout << "The name of second arc map: "
2351  ///           << contents.arcMaps(0)[1] << std::endl;
2352  ///\endcode
2353  class LgfContents {
2354  private:
2355
2356    std::istream* _is;
2357    bool local_is;
2358
2359    std::vector<std::string> _node_sections;
2360    std::vector<std::string> _edge_sections;
2361    std::vector<std::string> _attribute_sections;
2362    std::vector<std::string> _extra_sections;
2363
2364    std::vector<bool> _arc_sections;
2365
2366    std::vector<std::vector<std::string> > _node_maps;
2367    std::vector<std::vector<std::string> > _edge_maps;
2368
2369    std::vector<std::vector<std::string> > _attributes;
2370
2371
2372    int line_num;
2373    std::istringstream line;
2374
2375  public:
2376
2377    /// \brief Constructor
2378    ///
2379    /// Construct an \e LGF contents reader, which reads from the given
2380    /// input stream.
2381    LgfContents(std::istream& is)
2382      : _is(&is), local_is(false) {}
2383
2384    /// \brief Constructor
2385    ///
2386    /// Construct an \e LGF contents reader, which reads from the given
2387    /// file.
2388    LgfContents(const std::string& fn)
2389      : _is(new std::ifstream(fn.c_str())), local_is(true) {
2390      if (!(*_is)) throw IoError(fn, "Cannot open file");
2391    }
2392
2393    /// \brief Constructor
2394    ///
2395    /// Construct an \e LGF contents reader, which reads from the given
2396    /// file.
2397    LgfContents(const char* fn)
2398      : _is(new std::ifstream(fn)), local_is(true) {
2399      if (!(*_is)) throw IoError(fn, "Cannot open file");
2400    }
2401
2402    /// \brief Destructor
2403    ~LgfContents() {
2404      if (local_is) delete _is;
2405    }
2406
2407  private:
2408
2409    LgfContents(const LgfContents&);
2410    LgfContents& operator=(const LgfContents&);
2411
2412  public:
2413
2414
2415    /// \name Node sections
2416    /// @{
2417
2418    /// \brief Gives back the number of node sections in the file.
2419    ///
2420    /// Gives back the number of node sections in the file.
2421    int nodeSectionNum() const {
2422      return _node_sections.size();
2423    }
2424
2425    /// \brief Returns the node section name at the given position.
2426    ///
2427    /// Returns the node section name at the given position.
2428    const std::string& nodeSection(int i) const {
2429      return _node_sections[i];
2430    }
2431
2432    /// \brief Gives back the node maps for the given section.
2433    ///
2434    /// Gives back the node maps for the given section.
2435    const std::vector<std::string>& nodeMapNames(int i) const {
2436      return _node_maps[i];
2437    }
2438
2439    /// @}
2440
2441    /// \name Arc/Edge sections
2442    /// @{
2443
2444    /// \brief Gives back the number of arc/edge sections in the file.
2445    ///
2446    /// Gives back the number of arc/edge sections in the file.
2447    /// \note It is synonym of \c edgeSectionNum().
2448    int arcSectionNum() const {
2449      return _edge_sections.size();
2450    }
2451
2452    /// \brief Returns the arc/edge section name at the given position.
2453    ///
2454    /// Returns the arc/edge section name at the given position.
2455    /// \note It is synonym of \c edgeSection().
2456    const std::string& arcSection(int i) const {
2457      return _edge_sections[i];
2458    }
2459
2460    /// \brief Gives back the arc/edge maps for the given section.
2461    ///
2462    /// Gives back the arc/edge maps for the given section.
2463    /// \note It is synonym of \c edgeMapNames().
2464    const std::vector<std::string>& arcMapNames(int i) const {
2465      return _edge_maps[i];
2466    }
2467
2468    /// @}
2469
2470    /// \name Synonyms
2471    /// @{
2472
2473    /// \brief Gives back the number of arc/edge sections in the file.
2474    ///
2475    /// Gives back the number of arc/edge sections in the file.
2476    /// \note It is synonym of \c arcSectionNum().
2477    int edgeSectionNum() const {
2478      return _edge_sections.size();
2479    }
2480
2481    /// \brief Returns the section name at the given position.
2482    ///
2483    /// Returns the section name at the given position.
2484    /// \note It is synonym of \c arcSection().
2485    const std::string& edgeSection(int i) const {
2486      return _edge_sections[i];
2487    }
2488
2489    /// \brief Gives back the edge maps for the given section.
2490    ///
2491    /// Gives back the edge maps for the given section.
2492    /// \note It is synonym of \c arcMapNames().
2493    const std::vector<std::string>& edgeMapNames(int i) const {
2494      return _edge_maps[i];
2495    }
2496
2497    /// @}
2498
2499    /// \name Attribute sections
2500    /// @{
2501
2502    /// \brief Gives back the number of attribute sections in the file.
2503    ///
2504    /// Gives back the number of attribute sections in the file.
2505    int attributeSectionNum() const {
2506      return _attribute_sections.size();
2507    }
2508
2509    /// \brief Returns the attribute section name at the given position.
2510    ///
2511    /// Returns the attribute section name at the given position.
2512    const std::string& attributeSectionNames(int i) const {
2513      return _attribute_sections[i];
2514    }
2515
2516    /// \brief Gives back the attributes for the given section.
2517    ///
2518    /// Gives back the attributes for the given section.
2519    const std::vector<std::string>& attributes(int i) const {
2520      return _attributes[i];
2521    }
2522
2523    /// @}
2524
2525    /// \name Extra sections
2526    /// @{
2527
2528    /// \brief Gives back the number of extra sections in the file.
2529    ///
2530    /// Gives back the number of extra sections in the file.
2531    int extraSectionNum() const {
2532      return _extra_sections.size();
2533    }
2534
2535    /// \brief Returns the extra section type at the given position.
2536    ///
2537    /// Returns the section type at the given position.
2538    const std::string& extraSection(int i) const {
2539      return _extra_sections[i];
2540    }
2541
2542    /// @}
2543
2544  private:
2545
2546    bool readLine() {
2547      std::string str;
2548      while(++line_num, std::getline(*_is, str)) {
2549        line.clear(); line.str(str);
2550        char c;
2551        if (line >> std::ws >> c && c != '#') {
2552          line.putback(c);
2553          return true;
2554        }
2555      }
2556      return false;
2557    }
2558
2559    bool readSuccess() {
2560      return static_cast<bool>(*_is);
2561    }
2562
2563    void skipSection() {
2564      char c;
2565      while (readSuccess() && line >> c && c != '@') {
2566        readLine();
2567      }
2568      line.putback(c);
2569    }
2570
2571    void readMaps(std::vector<std::string>& maps) {
2572      char c;
2573      if (!readLine() || !(line >> c) || c == '@') {
2574        if (readSuccess() && line) line.putback(c);
2575        return;
2576      }
2577      line.putback(c);
2578      std::string map;
2579      while (_reader_bits::readToken(line, map)) {
2580        maps.push_back(map);
2581      }
2582    }
2583
2584    void readAttributes(std::vector<std::string>& attrs) {
2585      readLine();
2586      char c;
2587      while (readSuccess() && line >> c && c != '@') {
2588        line.putback(c);
2589        std::string attr;
2590        _reader_bits::readToken(line, attr);
2591        attrs.push_back(attr);
2592        readLine();
2593      }
2594      line.putback(c);
2595    }
2596
2597  public:
2598
2599    /// \name Execution of the contents reader
2600    /// @{
2601
2602    /// \brief Starts the reading
2603    ///
2604    /// This function starts the reading.
2605    void run() {
2606
2607      readLine();
2608      skipSection();
2609
2610      while (readSuccess()) {
2611
2612        char c;
2613        line >> c;
2614
2615        std::string section, caption;
2616        _reader_bits::readToken(line, section);
2617        _reader_bits::readToken(line, caption);
2618
2619        if (section == "nodes") {
2620          _node_sections.push_back(caption);
2621          _node_maps.push_back(std::vector<std::string>());
2622          readMaps(_node_maps.back());
2623          readLine(); skipSection();
2624        } else if (section == "arcs" || section == "edges") {
2625          _edge_sections.push_back(caption);
2626          _arc_sections.push_back(section == "arcs");
2627          _edge_maps.push_back(std::vector<std::string>());
2628          readMaps(_edge_maps.back());
2629          readLine(); skipSection();
2630        } else if (section == "attributes") {
2631          _attribute_sections.push_back(caption);
2632          _attributes.push_back(std::vector<std::string>());
2633          readAttributes(_attributes.back());
2634        } else {
2635          _extra_sections.push_back(section);
2636          readLine(); skipSection();
2637        }
2638      }
2639    }
2640
2641    /// @}
2642
2643  };
2644}
2645
2646#endif
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