COIN-OR::LEMON - Graph Library

source: lemon-1.2/lemon/lgf_reader.h @ 393:37054b67d807

Last change on this file since 393:37054b67d807 was 319:5e12d7734036, checked in by Alpar Juttner <alpar@…>, 11 years ago

arrert.h is now included by core.h (#161)

File size: 77.7 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/core.h>
35
36#include <lemon/lgf_writer.h>
37
38#include <lemon/concept_check.h>
39#include <lemon/concepts/maps.h>
40
41namespace lemon {
42
43  namespace _reader_bits {
44
45    template <typename Value>
46    struct DefaultConverter {
47      Value operator()(const std::string& str) {
48        std::istringstream is(str);
49        Value value;
50        if (!(is >> value)) {
51          throw FormatError("Cannot read token");
52        }
53
54        char c;
55        if (is >> std::ws >> c) {
56          throw FormatError("Remaining characters in token");
57        }
58        return value;
59      }
60    };
61
62    template <>
63    struct DefaultConverter<std::string> {
64      std::string operator()(const std::string& str) {
65        return str;
66      }
67    };
68
69    template <typename _Item>
70    class MapStorageBase {
71    public:
72      typedef _Item Item;
73
74    public:
75      MapStorageBase() {}
76      virtual ~MapStorageBase() {}
77
78      virtual void set(const Item& item, const std::string& value) = 0;
79
80    };
81
82    template <typename _Item, typename _Map,
83              typename _Converter = DefaultConverter<typename _Map::Value> >
84    class MapStorage : public MapStorageBase<_Item> {
85    public:
86      typedef _Map Map;
87      typedef _Converter Converter;
88      typedef _Item Item;
89
90    private:
91      Map& _map;
92      Converter _converter;
93
94    public:
95      MapStorage(Map& map, const Converter& converter = Converter())
96        : _map(map), _converter(converter) {}
97      virtual ~MapStorage() {}
98
99      virtual void set(const Item& item ,const std::string& value) {
100        _map.set(item, _converter(value));
101      }
102    };
103
104    template <typename _Graph, bool _dir, typename _Map,
105              typename _Converter = DefaultConverter<typename _Map::Value> >
106    class GraphArcMapStorage : public MapStorageBase<typename _Graph::Edge> {
107    public:
108      typedef _Map Map;
109      typedef _Converter Converter;
110      typedef _Graph Graph;
111      typedef typename Graph::Edge Item;
112      static const bool dir = _dir;
113
114    private:
115      const Graph& _graph;
116      Map& _map;
117      Converter _converter;
118
119    public:
120      GraphArcMapStorage(const Graph& graph, Map& map,
121                         const Converter& converter = Converter())
122        : _graph(graph), _map(map), _converter(converter) {}
123      virtual ~GraphArcMapStorage() {}
124
125      virtual void set(const Item& item ,const std::string& value) {
126        _map.set(_graph.direct(item, dir), _converter(value));
127      }
128    };
129
130    class ValueStorageBase {
131    public:
132      ValueStorageBase() {}
133      virtual ~ValueStorageBase() {}
134
135      virtual void set(const std::string&) = 0;
136    };
137
138    template <typename _Value, typename _Converter = DefaultConverter<_Value> >
139    class ValueStorage : public ValueStorageBase {
140    public:
141      typedef _Value Value;
142      typedef _Converter Converter;
143
144    private:
145      Value& _value;
146      Converter _converter;
147
148    public:
149      ValueStorage(Value& value, const Converter& converter = Converter())
150        : _value(value), _converter(converter) {}
151
152      virtual void set(const std::string& value) {
153        _value = _converter(value);
154      }
155    };
156
157    template <typename Value>
158    struct MapLookUpConverter {
159      const std::map<std::string, Value>& _map;
160
161      MapLookUpConverter(const std::map<std::string, Value>& map)
162        : _map(map) {}
163
164      Value operator()(const std::string& str) {
165        typename std::map<std::string, Value>::const_iterator it =
166          _map.find(str);
167        if (it == _map.end()) {
168          std::ostringstream msg;
169          msg << "Item not found: " << str;
170          throw FormatError(msg.str());
171        }
172        return it->second;
173      }
174    };
175
176    template <typename Graph>
177    struct GraphArcLookUpConverter {
178      const Graph& _graph;
179      const std::map<std::string, typename Graph::Edge>& _map;
180
181      GraphArcLookUpConverter(const Graph& graph,
182                              const std::map<std::string,
183                                             typename Graph::Edge>& map)
184        : _graph(graph), _map(map) {}
185
186      typename Graph::Arc operator()(const std::string& str) {
187        if (str.empty() || (str[0] != '+' && str[0] != '-')) {
188          throw FormatError("Item must start with '+' or '-'");
189        }
190        typename std::map<std::string, typename Graph::Edge>
191          ::const_iterator it = _map.find(str.substr(1));
192        if (it == _map.end()) {
193          throw FormatError("Item not found");
194        }
195        return _graph.direct(it->second, str[0] == '+');
196      }
197    };
198
199    inline bool isWhiteSpace(char c) {
200      return c == ' ' || c == '\t' || c == '\v' ||
201        c == '\n' || c == '\r' || c == '\f';
202    }
203
204    inline bool isOct(char c) {
205      return '0' <= c && c <='7';
206    }
207
208    inline int valueOct(char c) {
209      LEMON_ASSERT(isOct(c), "The character is not octal.");
210      return c - '0';
211    }
212
213    inline bool isHex(char c) {
214      return ('0' <= c && c <= '9') ||
215        ('a' <= c && c <= 'z') ||
216        ('A' <= c && c <= 'Z');
217    }
218
219    inline int valueHex(char c) {
220      LEMON_ASSERT(isHex(c), "The character is not hexadecimal.");
221      if ('0' <= c && c <= '9') return c - '0';
222      if ('a' <= c && c <= 'z') return c - 'a' + 10;
223      return c - 'A' + 10;
224    }
225
226    inline bool isIdentifierFirstChar(char c) {
227      return ('a' <= c && c <= 'z') ||
228        ('A' <= c && c <= 'Z') || c == '_';
229    }
230
231    inline bool isIdentifierChar(char c) {
232      return isIdentifierFirstChar(c) ||
233        ('0' <= c && c <= '9');
234    }
235
236    inline char readEscape(std::istream& is) {
237      char c;
238      if (!is.get(c))
239        throw FormatError("Escape format error");
240
241      switch (c) {
242      case '\\':
243        return '\\';
244      case '\"':
245        return '\"';
246      case '\'':
247        return '\'';
248      case '\?':
249        return '\?';
250      case 'a':
251        return '\a';
252      case 'b':
253        return '\b';
254      case 'f':
255        return '\f';
256      case 'n':
257        return '\n';
258      case 'r':
259        return '\r';
260      case 't':
261        return '\t';
262      case 'v':
263        return '\v';
264      case 'x':
265        {
266          int code;
267          if (!is.get(c) || !isHex(c))
268            throw FormatError("Escape format error");
269          else if (code = valueHex(c), !is.get(c) || !isHex(c)) is.putback(c);
270          else code = code * 16 + valueHex(c);
271          return code;
272        }
273      default:
274        {
275          int code;
276          if (!isOct(c))
277            throw FormatError("Escape format error");
278          else if (code = valueOct(c), !is.get(c) || !isOct(c))
279            is.putback(c);
280          else if (code = code * 8 + valueOct(c), !is.get(c) || !isOct(c))
281            is.putback(c);
282          else code = code * 8 + valueOct(c);
283          return code;
284        }
285      }
286    }
287
288    inline std::istream& readToken(std::istream& is, std::string& str) {
289      std::ostringstream os;
290
291      char c;
292      is >> std::ws;
293
294      if (!is.get(c))
295        return is;
296
297      if (c == '\"') {
298        while (is.get(c) && c != '\"') {
299          if (c == '\\')
300            c = readEscape(is);
301          os << c;
302        }
303        if (!is)
304          throw FormatError("Quoted format error");
305      } else {
306        is.putback(c);
307        while (is.get(c) && !isWhiteSpace(c)) {
308          if (c == '\\')
309            c = readEscape(is);
310          os << c;
311        }
312        if (!is) {
313          is.clear();
314        } else {
315          is.putback(c);
316        }
317      }
318      str = os.str();
319      return is;
320    }
321
322    class Section {
323    public:
324      virtual ~Section() {}
325      virtual void process(std::istream& is, int& line_num) = 0;
326    };
327
328    template <typename Functor>
329    class LineSection : public Section {
330    private:
331
332      Functor _functor;
333
334    public:
335
336      LineSection(const Functor& functor) : _functor(functor) {}
337      virtual ~LineSection() {}
338
339      virtual void process(std::istream& is, int& line_num) {
340        char c;
341        std::string line;
342        while (is.get(c) && c != '@') {
343          if (c == '\n') {
344            ++line_num;
345          } else if (c == '#') {
346            getline(is, line);
347            ++line_num;
348          } else if (!isWhiteSpace(c)) {
349            is.putback(c);
350            getline(is, line);
351            _functor(line);
352            ++line_num;
353          }
354        }
355        if (is) is.putback(c);
356        else if (is.eof()) is.clear();
357      }
358    };
359
360    template <typename Functor>
361    class StreamSection : public Section {
362    private:
363
364      Functor _functor;
365
366    public:
367
368      StreamSection(const Functor& functor) : _functor(functor) {}
369      virtual ~StreamSection() {}
370
371      virtual void process(std::istream& is, int& line_num) {
372        _functor(is, line_num);
373        char c;
374        std::string line;
375        while (is.get(c) && c != '@') {
376          if (c == '\n') {
377            ++line_num;
378          } else if (!isWhiteSpace(c)) {
379            getline(is, line);
380            ++line_num;
381          }
382        }
383        if (is) is.putback(c);
384        else if (is.eof()) is.clear();
385      }
386    };
387
388  }
389
390  template <typename Digraph>
391  class DigraphReader;
392
393  /// \brief Return a \ref DigraphReader class
394  ///
395  /// This function just returns a \ref DigraphReader class.
396  /// \relates DigraphReader
397  template <typename Digraph>
398  DigraphReader<Digraph> digraphReader(Digraph& digraph,
399                                       std::istream& is = std::cin) {
400    DigraphReader<Digraph> tmp(digraph, is);
401    return tmp;
402  }
403
404  /// \brief Return a \ref DigraphReader class
405  ///
406  /// This function just returns a \ref DigraphReader class.
407  /// \relates DigraphReader
408  template <typename Digraph>
409  DigraphReader<Digraph> digraphReader(Digraph& digraph,
410                                       const std::string& fn) {
411    DigraphReader<Digraph> tmp(digraph, fn);
412    return tmp;
413  }
414
415  /// \brief Return a \ref DigraphReader class
416  ///
417  /// This function just returns a \ref DigraphReader class.
418  /// \relates DigraphReader
419  template <typename Digraph>
420  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char* fn) {
421    DigraphReader<Digraph> tmp(digraph, fn);
422    return tmp;
423  }
424
425  /// \ingroup lemon_io
426  ///
427  /// \brief \ref lgf-format "LGF" reader for directed graphs
428  ///
429  /// This utility reads an \ref lgf-format "LGF" file.
430  ///
431  /// The reading method does a batch processing. The user creates a
432  /// reader object, then various reading rules can be added to the
433  /// reader, and eventually the reading is executed with the \c run()
434  /// member function. A map reading rule can be added to the reader
435  /// with the \c nodeMap() or \c arcMap() members. An optional
436  /// converter parameter can also be added as a standard functor
437  /// converting from \c std::string to the value type of the map. If it
438  /// is set, it will determine how the tokens in the file should be
439  /// converted to the value type of the map. If the functor is not set,
440  /// then a default conversion will be used. One map can be read into
441  /// multiple map objects at the same time. The \c attribute(), \c
442  /// node() and \c arc() functions are used to add attribute reading
443  /// rules.
444  ///
445  ///\code
446  /// DigraphReader<Digraph>(digraph, std::cin).
447  ///   nodeMap("coordinates", coord_map).
448  ///   arcMap("capacity", cap_map).
449  ///   node("source", src).
450  ///   node("target", trg).
451  ///   attribute("caption", caption).
452  ///   run();
453  ///\endcode
454  ///
455  /// By default the reader uses the first section in the file of the
456  /// proper type. If a section has an optional name, then it can be
457  /// selected for reading by giving an optional name parameter to the
458  /// \c nodes(), \c arcs() or \c attributes() functions.
459  ///
460  /// The \c useNodes() and \c useArcs() functions are used to tell the reader
461  /// that the nodes or arcs should not be constructed (added to the
462  /// graph) during the reading, but instead the label map of the items
463  /// are given as a parameter of these functions. An
464  /// application of these functions is multipass reading, which is
465  /// important if two \c \@arcs sections must be read from the
466  /// file. In this case the first phase would read the node set and one
467  /// of the arc sets, while the second phase would read the second arc
468  /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
469  /// The previously read label node map should be passed to the \c
470  /// useNodes() functions. Another application of multipass reading when
471  /// paths are given as a node map or an arc map.
472  /// It is impossible to read this in
473  /// a single pass, because the arcs are not constructed when the node
474  /// maps are read.
475  template <typename _Digraph>
476  class DigraphReader {
477  public:
478
479    typedef _Digraph Digraph;
480    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
481
482  private:
483
484
485    std::istream* _is;
486    bool local_is;
487    std::string _filename;
488
489    Digraph& _digraph;
490
491    std::string _nodes_caption;
492    std::string _arcs_caption;
493    std::string _attributes_caption;
494
495    typedef std::map<std::string, Node> NodeIndex;
496    NodeIndex _node_index;
497    typedef std::map<std::string, Arc> ArcIndex;
498    ArcIndex _arc_index;
499
500    typedef std::vector<std::pair<std::string,
501      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
502    NodeMaps _node_maps;
503
504    typedef std::vector<std::pair<std::string,
505      _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
506    ArcMaps _arc_maps;
507
508    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
509      Attributes;
510    Attributes _attributes;
511
512    bool _use_nodes;
513    bool _use_arcs;
514
515    bool _skip_nodes;
516    bool _skip_arcs;
517
518    int line_num;
519    std::istringstream line;
520
521  public:
522
523    /// \brief Constructor
524    ///
525    /// Construct a directed graph reader, which reads from the given
526    /// input stream.
527    DigraphReader(Digraph& digraph, std::istream& is = std::cin)
528      : _is(&is), local_is(false), _digraph(digraph),
529        _use_nodes(false), _use_arcs(false),
530        _skip_nodes(false), _skip_arcs(false) {}
531
532    /// \brief Constructor
533    ///
534    /// Construct a directed graph reader, which reads from the given
535    /// file.
536    DigraphReader(Digraph& digraph, const std::string& fn)
537      : _is(new std::ifstream(fn.c_str())), local_is(true),
538        _filename(fn), _digraph(digraph),
539        _use_nodes(false), _use_arcs(false),
540        _skip_nodes(false), _skip_arcs(false) {
541      if (!(*_is)) {
542        delete _is;
543        throw IoError("Cannot open file", fn);
544      }
545    }
546
547    /// \brief Constructor
548    ///
549    /// Construct a directed graph reader, which reads from the given
550    /// file.
551    DigraphReader(Digraph& digraph, const char* fn)
552      : _is(new std::ifstream(fn)), local_is(true),
553        _filename(fn), _digraph(digraph),
554        _use_nodes(false), _use_arcs(false),
555        _skip_nodes(false), _skip_arcs(false) {
556      if (!(*_is)) {
557        delete _is;
558        throw IoError("Cannot open file", fn);
559      }
560    }
561
562    /// \brief Destructor
563    ~DigraphReader() {
564      for (typename NodeMaps::iterator it = _node_maps.begin();
565           it != _node_maps.end(); ++it) {
566        delete it->second;
567      }
568
569      for (typename ArcMaps::iterator it = _arc_maps.begin();
570           it != _arc_maps.end(); ++it) {
571        delete it->second;
572      }
573
574      for (typename Attributes::iterator it = _attributes.begin();
575           it != _attributes.end(); ++it) {
576        delete it->second;
577      }
578
579      if (local_is) {
580        delete _is;
581      }
582
583    }
584
585  private:
586
587    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
588                                                  std::istream& is);
589    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
590                                                  const std::string& fn);
591    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
592                                                  const char *fn);
593
594    DigraphReader(DigraphReader& other)
595      : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
596        _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
597        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
598
599      other._is = 0;
600      other.local_is = false;
601
602      _node_index.swap(other._node_index);
603      _arc_index.swap(other._arc_index);
604
605      _node_maps.swap(other._node_maps);
606      _arc_maps.swap(other._arc_maps);
607      _attributes.swap(other._attributes);
608
609      _nodes_caption = other._nodes_caption;
610      _arcs_caption = other._arcs_caption;
611      _attributes_caption = other._attributes_caption;
612
613    }
614
615    DigraphReader& operator=(const DigraphReader&);
616
617  public:
618
619    /// \name Reading rules
620    /// @{
621
622    /// \brief Node map reading rule
623    ///
624    /// Add a node map reading rule to the reader.
625    template <typename Map>
626    DigraphReader& nodeMap(const std::string& caption, Map& map) {
627      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
628      _reader_bits::MapStorageBase<Node>* storage =
629        new _reader_bits::MapStorage<Node, Map>(map);
630      _node_maps.push_back(std::make_pair(caption, storage));
631      return *this;
632    }
633
634    /// \brief Node map reading rule
635    ///
636    /// Add a node map reading rule with specialized converter to the
637    /// reader.
638    template <typename Map, typename Converter>
639    DigraphReader& nodeMap(const std::string& caption, Map& map,
640                           const Converter& converter = Converter()) {
641      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
642      _reader_bits::MapStorageBase<Node>* storage =
643        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
644      _node_maps.push_back(std::make_pair(caption, storage));
645      return *this;
646    }
647
648    /// \brief Arc map reading rule
649    ///
650    /// Add an arc map reading rule to the reader.
651    template <typename Map>
652    DigraphReader& arcMap(const std::string& caption, Map& map) {
653      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
654      _reader_bits::MapStorageBase<Arc>* storage =
655        new _reader_bits::MapStorage<Arc, Map>(map);
656      _arc_maps.push_back(std::make_pair(caption, storage));
657      return *this;
658    }
659
660    /// \brief Arc map reading rule
661    ///
662    /// Add an arc map reading rule with specialized converter to the
663    /// reader.
664    template <typename Map, typename Converter>
665    DigraphReader& arcMap(const std::string& caption, Map& map,
666                          const Converter& converter = Converter()) {
667      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
668      _reader_bits::MapStorageBase<Arc>* storage =
669        new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
670      _arc_maps.push_back(std::make_pair(caption, storage));
671      return *this;
672    }
673
674    /// \brief Attribute reading rule
675    ///
676    /// Add an attribute reading rule to the reader.
677    template <typename Value>
678    DigraphReader& attribute(const std::string& caption, Value& value) {
679      _reader_bits::ValueStorageBase* storage =
680        new _reader_bits::ValueStorage<Value>(value);
681      _attributes.insert(std::make_pair(caption, storage));
682      return *this;
683    }
684
685    /// \brief Attribute reading rule
686    ///
687    /// Add an attribute reading rule with specialized converter to the
688    /// reader.
689    template <typename Value, typename Converter>
690    DigraphReader& attribute(const std::string& caption, Value& value,
691                             const Converter& converter = Converter()) {
692      _reader_bits::ValueStorageBase* storage =
693        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
694      _attributes.insert(std::make_pair(caption, storage));
695      return *this;
696    }
697
698    /// \brief Node reading rule
699    ///
700    /// Add a node reading rule to reader.
701    DigraphReader& node(const std::string& caption, Node& node) {
702      typedef _reader_bits::MapLookUpConverter<Node> Converter;
703      Converter converter(_node_index);
704      _reader_bits::ValueStorageBase* storage =
705        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
706      _attributes.insert(std::make_pair(caption, storage));
707      return *this;
708    }
709
710    /// \brief Arc reading rule
711    ///
712    /// Add an arc reading rule to reader.
713    DigraphReader& arc(const std::string& caption, Arc& arc) {
714      typedef _reader_bits::MapLookUpConverter<Arc> Converter;
715      Converter converter(_arc_index);
716      _reader_bits::ValueStorageBase* storage =
717        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
718      _attributes.insert(std::make_pair(caption, storage));
719      return *this;
720    }
721
722    /// @}
723
724    /// \name Select section by name
725    /// @{
726
727    /// \brief Set \c \@nodes section to be read
728    ///
729    /// Set \c \@nodes section to be read
730    DigraphReader& nodes(const std::string& caption) {
731      _nodes_caption = caption;
732      return *this;
733    }
734
735    /// \brief Set \c \@arcs section to be read
736    ///
737    /// Set \c \@arcs section to be read
738    DigraphReader& arcs(const std::string& caption) {
739      _arcs_caption = caption;
740      return *this;
741    }
742
743    /// \brief Set \c \@attributes section to be read
744    ///
745    /// Set \c \@attributes section to be read
746    DigraphReader& attributes(const std::string& caption) {
747      _attributes_caption = caption;
748      return *this;
749    }
750
751    /// @}
752
753    /// \name Using previously constructed node or arc set
754    /// @{
755
756    /// \brief Use previously constructed node set
757    ///
758    /// Use previously constructed node set, and specify the node
759    /// label map.
760    template <typename Map>
761    DigraphReader& useNodes(const Map& map) {
762      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
763      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
764      _use_nodes = true;
765      _writer_bits::DefaultConverter<typename Map::Value> converter;
766      for (NodeIt n(_digraph); n != INVALID; ++n) {
767        _node_index.insert(std::make_pair(converter(map[n]), n));
768      }
769      return *this;
770    }
771
772    /// \brief Use previously constructed node set
773    ///
774    /// Use previously constructed node set, and specify the node
775    /// label map and a functor which converts the label map values to
776    /// \c std::string.
777    template <typename Map, typename Converter>
778    DigraphReader& useNodes(const Map& map,
779                            const Converter& converter = Converter()) {
780      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
781      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
782      _use_nodes = true;
783      for (NodeIt n(_digraph); n != INVALID; ++n) {
784        _node_index.insert(std::make_pair(converter(map[n]), n));
785      }
786      return *this;
787    }
788
789    /// \brief Use previously constructed arc set
790    ///
791    /// Use previously constructed arc set, and specify the arc
792    /// label map.
793    template <typename Map>
794    DigraphReader& useArcs(const Map& map) {
795      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
796      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
797      _use_arcs = true;
798      _writer_bits::DefaultConverter<typename Map::Value> converter;
799      for (ArcIt a(_digraph); a != INVALID; ++a) {
800        _arc_index.insert(std::make_pair(converter(map[a]), a));
801      }
802      return *this;
803    }
804
805    /// \brief Use previously constructed arc set
806    ///
807    /// Use previously constructed arc set, and specify the arc
808    /// label map and a functor which converts the label map values to
809    /// \c std::string.
810    template <typename Map, typename Converter>
811    DigraphReader& useArcs(const Map& map,
812                           const Converter& converter = Converter()) {
813      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
814      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
815      _use_arcs = true;
816      for (ArcIt a(_digraph); a != INVALID; ++a) {
817        _arc_index.insert(std::make_pair(converter(map[a]), a));
818      }
819      return *this;
820    }
821
822    /// \brief Skips the reading of node section
823    ///
824    /// Omit the reading of the node section. This implies that each node
825    /// map reading rule will be abandoned, and the nodes of the graph
826    /// will not be constructed, which usually cause that the arc set
827    /// could not be read due to lack of node name resolving.
828    /// Therefore \c skipArcs() function should also be used, or
829    /// \c useNodes() should be used to specify the label of the nodes.
830    DigraphReader& skipNodes() {
831      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
832      _skip_nodes = true;
833      return *this;
834    }
835
836    /// \brief Skips the reading of arc section
837    ///
838    /// Omit the reading of the arc section. This implies that each arc
839    /// map reading rule will be abandoned, and the arcs of the graph
840    /// will not be constructed.
841    DigraphReader& skipArcs() {
842      LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
843      _skip_arcs = true;
844      return *this;
845    }
846
847    /// @}
848
849  private:
850
851    bool readLine() {
852      std::string str;
853      while(++line_num, std::getline(*_is, str)) {
854        line.clear(); line.str(str);
855        char c;
856        if (line >> std::ws >> c && c != '#') {
857          line.putback(c);
858          return true;
859        }
860      }
861      return false;
862    }
863
864    bool readSuccess() {
865      return static_cast<bool>(*_is);
866    }
867
868    void skipSection() {
869      char c;
870      while (readSuccess() && line >> c && c != '@') {
871        readLine();
872      }
873      line.putback(c);
874    }
875
876    void readNodes() {
877
878      std::vector<int> map_index(_node_maps.size());
879      int map_num, label_index;
880
881      char c;
882      if (!readLine() || !(line >> c) || c == '@') {
883        if (readSuccess() && line) line.putback(c);
884        if (!_node_maps.empty())
885          throw FormatError("Cannot find map names");
886        return;
887      }
888      line.putback(c);
889
890      {
891        std::map<std::string, int> maps;
892
893        std::string map;
894        int index = 0;
895        while (_reader_bits::readToken(line, map)) {
896          if (maps.find(map) != maps.end()) {
897            std::ostringstream msg;
898            msg << "Multiple occurence of node map: " << map;
899            throw FormatError(msg.str());
900          }
901          maps.insert(std::make_pair(map, index));
902          ++index;
903        }
904
905        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
906          std::map<std::string, int>::iterator jt =
907            maps.find(_node_maps[i].first);
908          if (jt == maps.end()) {
909            std::ostringstream msg;
910            msg << "Map not found: " << _node_maps[i].first;
911            throw FormatError(msg.str());
912          }
913          map_index[i] = jt->second;
914        }
915
916        {
917          std::map<std::string, int>::iterator jt = maps.find("label");
918          if (jt != maps.end()) {
919            label_index = jt->second;
920          } else {
921            label_index = -1;
922          }
923        }
924        map_num = maps.size();
925      }
926
927      while (readLine() && line >> c && c != '@') {
928        line.putback(c);
929
930        std::vector<std::string> tokens(map_num);
931        for (int i = 0; i < map_num; ++i) {
932          if (!_reader_bits::readToken(line, tokens[i])) {
933            std::ostringstream msg;
934            msg << "Column not found (" << i + 1 << ")";
935            throw FormatError(msg.str());
936          }
937        }
938        if (line >> std::ws >> c)
939          throw FormatError("Extra character at the end of line");
940
941        Node n;
942        if (!_use_nodes) {
943          n = _digraph.addNode();
944          if (label_index != -1)
945            _node_index.insert(std::make_pair(tokens[label_index], n));
946        } else {
947          if (label_index == -1)
948            throw FormatError("Label map not found");
949          typename std::map<std::string, Node>::iterator it =
950            _node_index.find(tokens[label_index]);
951          if (it == _node_index.end()) {
952            std::ostringstream msg;
953            msg << "Node with label not found: " << tokens[label_index];
954            throw FormatError(msg.str());
955          }
956          n = it->second;
957        }
958
959        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
960          _node_maps[i].second->set(n, tokens[map_index[i]]);
961        }
962
963      }
964      if (readSuccess()) {
965        line.putback(c);
966      }
967    }
968
969    void readArcs() {
970
971      std::vector<int> map_index(_arc_maps.size());
972      int map_num, label_index;
973
974      char c;
975      if (!readLine() || !(line >> c) || c == '@') {
976        if (readSuccess() && line) line.putback(c);
977        if (!_arc_maps.empty())
978          throw FormatError("Cannot find map names");
979        return;
980      }
981      line.putback(c);
982
983      {
984        std::map<std::string, int> maps;
985
986        std::string map;
987        int index = 0;
988        while (_reader_bits::readToken(line, map)) {
989          if (maps.find(map) != maps.end()) {
990            std::ostringstream msg;
991            msg << "Multiple occurence of arc map: " << map;
992            throw FormatError(msg.str());
993          }
994          maps.insert(std::make_pair(map, index));
995          ++index;
996        }
997
998        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
999          std::map<std::string, int>::iterator jt =
1000            maps.find(_arc_maps[i].first);
1001          if (jt == maps.end()) {
1002            std::ostringstream msg;
1003            msg << "Map not found: " << _arc_maps[i].first;
1004            throw FormatError(msg.str());
1005          }
1006          map_index[i] = jt->second;
1007        }
1008
1009        {
1010          std::map<std::string, int>::iterator jt = maps.find("label");
1011          if (jt != maps.end()) {
1012            label_index = jt->second;
1013          } else {
1014            label_index = -1;
1015          }
1016        }
1017        map_num = maps.size();
1018      }
1019
1020      while (readLine() && line >> c && c != '@') {
1021        line.putback(c);
1022
1023        std::string source_token;
1024        std::string target_token;
1025
1026        if (!_reader_bits::readToken(line, source_token))
1027          throw FormatError("Source not found");
1028
1029        if (!_reader_bits::readToken(line, target_token))
1030          throw FormatError("Target not found");
1031
1032        std::vector<std::string> tokens(map_num);
1033        for (int i = 0; i < map_num; ++i) {
1034          if (!_reader_bits::readToken(line, tokens[i])) {
1035            std::ostringstream msg;
1036            msg << "Column not found (" << i + 1 << ")";
1037            throw FormatError(msg.str());
1038          }
1039        }
1040        if (line >> std::ws >> c)
1041          throw FormatError("Extra character at the end of line");
1042
1043        Arc a;
1044        if (!_use_arcs) {
1045
1046          typename NodeIndex::iterator it;
1047
1048          it = _node_index.find(source_token);
1049          if (it == _node_index.end()) {
1050            std::ostringstream msg;
1051            msg << "Item not found: " << source_token;
1052            throw FormatError(msg.str());
1053          }
1054          Node source = it->second;
1055
1056          it = _node_index.find(target_token);
1057          if (it == _node_index.end()) {
1058            std::ostringstream msg;
1059            msg << "Item not found: " << target_token;
1060            throw FormatError(msg.str());
1061          }
1062          Node target = it->second;
1063
1064          a = _digraph.addArc(source, target);
1065          if (label_index != -1)
1066            _arc_index.insert(std::make_pair(tokens[label_index], a));
1067        } else {
1068          if (label_index == -1)
1069            throw FormatError("Label map not found");
1070          typename std::map<std::string, Arc>::iterator it =
1071            _arc_index.find(tokens[label_index]);
1072          if (it == _arc_index.end()) {
1073            std::ostringstream msg;
1074            msg << "Arc with label not found: " << tokens[label_index];
1075            throw FormatError(msg.str());
1076          }
1077          a = it->second;
1078        }
1079
1080        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
1081          _arc_maps[i].second->set(a, tokens[map_index[i]]);
1082        }
1083
1084      }
1085      if (readSuccess()) {
1086        line.putback(c);
1087      }
1088    }
1089
1090    void readAttributes() {
1091
1092      std::set<std::string> read_attr;
1093
1094      char c;
1095      while (readLine() && line >> c && c != '@') {
1096        line.putback(c);
1097
1098        std::string attr, token;
1099        if (!_reader_bits::readToken(line, attr))
1100          throw FormatError("Attribute name not found");
1101        if (!_reader_bits::readToken(line, token))
1102          throw FormatError("Attribute value not found");
1103        if (line >> c)
1104          throw FormatError("Extra character at the end of line");
1105
1106        {
1107          std::set<std::string>::iterator it = read_attr.find(attr);
1108          if (it != read_attr.end()) {
1109            std::ostringstream msg;
1110            msg << "Multiple occurence of attribute: " << attr;
1111            throw FormatError(msg.str());
1112          }
1113          read_attr.insert(attr);
1114        }
1115
1116        {
1117          typename Attributes::iterator it = _attributes.lower_bound(attr);
1118          while (it != _attributes.end() && it->first == attr) {
1119            it->second->set(token);
1120            ++it;
1121          }
1122        }
1123
1124      }
1125      if (readSuccess()) {
1126        line.putback(c);
1127      }
1128      for (typename Attributes::iterator it = _attributes.begin();
1129           it != _attributes.end(); ++it) {
1130        if (read_attr.find(it->first) == read_attr.end()) {
1131          std::ostringstream msg;
1132          msg << "Attribute not found: " << it->first;
1133          throw FormatError(msg.str());
1134        }
1135      }
1136    }
1137
1138  public:
1139
1140    /// \name Execution of the reader
1141    /// @{
1142
1143    /// \brief Start the batch processing
1144    ///
1145    /// This function starts the batch processing
1146    void run() {
1147      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1148
1149      bool nodes_done = _skip_nodes;
1150      bool arcs_done = _skip_arcs;
1151      bool attributes_done = false;
1152
1153      line_num = 0;
1154      readLine();
1155      skipSection();
1156
1157      while (readSuccess()) {
1158        try {
1159          char c;
1160          std::string section, caption;
1161          line >> c;
1162          _reader_bits::readToken(line, section);
1163          _reader_bits::readToken(line, caption);
1164
1165          if (line >> c)
1166            throw FormatError("Extra character at the end of line");
1167
1168          if (section == "nodes" && !nodes_done) {
1169            if (_nodes_caption.empty() || _nodes_caption == caption) {
1170              readNodes();
1171              nodes_done = true;
1172            }
1173          } else if ((section == "arcs" || section == "edges") &&
1174                     !arcs_done) {
1175            if (_arcs_caption.empty() || _arcs_caption == caption) {
1176              readArcs();
1177              arcs_done = true;
1178            }
1179          } else if (section == "attributes" && !attributes_done) {
1180            if (_attributes_caption.empty() || _attributes_caption == caption) {
1181              readAttributes();
1182              attributes_done = true;
1183            }
1184          } else {
1185            readLine();
1186            skipSection();
1187          }
1188        } catch (FormatError& error) {
1189          error.line(line_num);
1190          error.file(_filename);
1191          throw;
1192        }
1193      }
1194
1195      if (!nodes_done) {
1196        throw FormatError("Section @nodes not found");
1197      }
1198
1199      if (!arcs_done) {
1200        throw FormatError("Section @arcs not found");
1201      }
1202
1203      if (!attributes_done && !_attributes.empty()) {
1204        throw FormatError("Section @attributes not found");
1205      }
1206
1207    }
1208
1209    /// @}
1210
1211  };
1212
1213  template <typename Graph>
1214  class GraphReader;
1215
1216  /// \brief Return a \ref GraphReader class
1217  ///
1218  /// This function just returns a \ref GraphReader class.
1219  /// \relates GraphReader
1220  template <typename Graph>
1221  GraphReader<Graph> graphReader(Graph& graph, std::istream& is = std::cin) {
1222    GraphReader<Graph> tmp(graph, is);
1223    return tmp;
1224  }
1225
1226  /// \brief Return a \ref GraphReader class
1227  ///
1228  /// This function just returns a \ref GraphReader class.
1229  /// \relates GraphReader
1230  template <typename Graph>
1231  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {
1232    GraphReader<Graph> tmp(graph, fn);
1233    return tmp;
1234  }
1235
1236  /// \brief Return a \ref GraphReader class
1237  ///
1238  /// This function just returns a \ref GraphReader class.
1239  /// \relates GraphReader
1240  template <typename Graph>
1241  GraphReader<Graph> graphReader(Graph& graph, const char* fn) {
1242    GraphReader<Graph> tmp(graph, fn);
1243    return tmp;
1244  }
1245
1246  /// \ingroup lemon_io
1247  ///
1248  /// \brief \ref lgf-format "LGF" reader for undirected graphs
1249  ///
1250  /// This utility reads an \ref lgf-format "LGF" file.
1251  ///
1252  /// It can be used almost the same way as \c DigraphReader.
1253  /// The only difference is that this class can handle edges and
1254  /// edge maps as well as arcs and arc maps.
1255  ///
1256  /// The columns in the \c \@edges (or \c \@arcs) section are the
1257  /// edge maps. However, if there are two maps with the same name
1258  /// prefixed with \c '+' and \c '-', then these can be read into an
1259  /// arc map.  Similarly, an attribute can be read into an arc, if
1260  /// it's value is an edge label prefixed with \c '+' or \c '-'.
1261  template <typename _Graph>
1262  class GraphReader {
1263  public:
1264
1265    typedef _Graph Graph;
1266    TEMPLATE_GRAPH_TYPEDEFS(Graph);
1267
1268  private:
1269
1270    std::istream* _is;
1271    bool local_is;
1272    std::string _filename;
1273
1274    Graph& _graph;
1275
1276    std::string _nodes_caption;
1277    std::string _edges_caption;
1278    std::string _attributes_caption;
1279
1280    typedef std::map<std::string, Node> NodeIndex;
1281    NodeIndex _node_index;
1282    typedef std::map<std::string, Edge> EdgeIndex;
1283    EdgeIndex _edge_index;
1284
1285    typedef std::vector<std::pair<std::string,
1286      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
1287    NodeMaps _node_maps;
1288
1289    typedef std::vector<std::pair<std::string,
1290      _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
1291    EdgeMaps _edge_maps;
1292
1293    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
1294      Attributes;
1295    Attributes _attributes;
1296
1297    bool _use_nodes;
1298    bool _use_edges;
1299
1300    bool _skip_nodes;
1301    bool _skip_edges;
1302
1303    int line_num;
1304    std::istringstream line;
1305
1306  public:
1307
1308    /// \brief Constructor
1309    ///
1310    /// Construct an undirected graph reader, which reads from the given
1311    /// input stream.
1312    GraphReader(Graph& graph, std::istream& is = std::cin)
1313      : _is(&is), local_is(false), _graph(graph),
1314        _use_nodes(false), _use_edges(false),
1315        _skip_nodes(false), _skip_edges(false) {}
1316
1317    /// \brief Constructor
1318    ///
1319    /// Construct an undirected graph reader, which reads from the given
1320    /// file.
1321    GraphReader(Graph& graph, const std::string& fn)
1322      : _is(new std::ifstream(fn.c_str())), local_is(true),
1323        _filename(fn), _graph(graph),
1324        _use_nodes(false), _use_edges(false),
1325        _skip_nodes(false), _skip_edges(false) {
1326      if (!(*_is)) {
1327        delete _is;
1328        throw IoError("Cannot open file", fn);
1329      }
1330    }
1331
1332    /// \brief Constructor
1333    ///
1334    /// Construct an undirected graph reader, which reads from the given
1335    /// file.
1336    GraphReader(Graph& graph, const char* fn)
1337      : _is(new std::ifstream(fn)), local_is(true),
1338        _filename(fn), _graph(graph),
1339        _use_nodes(false), _use_edges(false),
1340        _skip_nodes(false), _skip_edges(false) {
1341      if (!(*_is)) {
1342        delete _is;
1343        throw IoError("Cannot open file", fn);
1344      }
1345    }
1346
1347    /// \brief Destructor
1348    ~GraphReader() {
1349      for (typename NodeMaps::iterator it = _node_maps.begin();
1350           it != _node_maps.end(); ++it) {
1351        delete it->second;
1352      }
1353
1354      for (typename EdgeMaps::iterator it = _edge_maps.begin();
1355           it != _edge_maps.end(); ++it) {
1356        delete it->second;
1357      }
1358
1359      for (typename Attributes::iterator it = _attributes.begin();
1360           it != _attributes.end(); ++it) {
1361        delete it->second;
1362      }
1363
1364      if (local_is) {
1365        delete _is;
1366      }
1367
1368    }
1369
1370  private:
1371    friend GraphReader<Graph> graphReader<>(Graph& graph, std::istream& is);
1372    friend GraphReader<Graph> graphReader<>(Graph& graph,
1373                                            const std::string& fn);
1374    friend GraphReader<Graph> graphReader<>(Graph& graph, const char *fn);
1375
1376    GraphReader(GraphReader& other)
1377      : _is(other._is), local_is(other.local_is), _graph(other._graph),
1378        _use_nodes(other._use_nodes), _use_edges(other._use_edges),
1379        _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
1380
1381      other._is = 0;
1382      other.local_is = false;
1383
1384      _node_index.swap(other._node_index);
1385      _edge_index.swap(other._edge_index);
1386
1387      _node_maps.swap(other._node_maps);
1388      _edge_maps.swap(other._edge_maps);
1389      _attributes.swap(other._attributes);
1390
1391      _nodes_caption = other._nodes_caption;
1392      _edges_caption = other._edges_caption;
1393      _attributes_caption = other._attributes_caption;
1394
1395    }
1396
1397    GraphReader& operator=(const GraphReader&);
1398
1399  public:
1400
1401    /// \name Reading rules
1402    /// @{
1403
1404    /// \brief Node map reading rule
1405    ///
1406    /// Add a node map reading rule to the reader.
1407    template <typename Map>
1408    GraphReader& nodeMap(const std::string& caption, Map& map) {
1409      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1410      _reader_bits::MapStorageBase<Node>* storage =
1411        new _reader_bits::MapStorage<Node, Map>(map);
1412      _node_maps.push_back(std::make_pair(caption, storage));
1413      return *this;
1414    }
1415
1416    /// \brief Node map reading rule
1417    ///
1418    /// Add a node map reading rule with specialized converter to the
1419    /// reader.
1420    template <typename Map, typename Converter>
1421    GraphReader& nodeMap(const std::string& caption, Map& map,
1422                           const Converter& converter = Converter()) {
1423      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1424      _reader_bits::MapStorageBase<Node>* storage =
1425        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
1426      _node_maps.push_back(std::make_pair(caption, storage));
1427      return *this;
1428    }
1429
1430    /// \brief Edge map reading rule
1431    ///
1432    /// Add an edge map reading rule to the reader.
1433    template <typename Map>
1434    GraphReader& edgeMap(const std::string& caption, Map& map) {
1435      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1436      _reader_bits::MapStorageBase<Edge>* storage =
1437        new _reader_bits::MapStorage<Edge, Map>(map);
1438      _edge_maps.push_back(std::make_pair(caption, storage));
1439      return *this;
1440    }
1441
1442    /// \brief Edge map reading rule
1443    ///
1444    /// Add an edge map reading rule with specialized converter to the
1445    /// reader.
1446    template <typename Map, typename Converter>
1447    GraphReader& edgeMap(const std::string& caption, Map& map,
1448                          const Converter& converter = Converter()) {
1449      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1450      _reader_bits::MapStorageBase<Edge>* storage =
1451        new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
1452      _edge_maps.push_back(std::make_pair(caption, storage));
1453      return *this;
1454    }
1455
1456    /// \brief Arc map reading rule
1457    ///
1458    /// Add an arc map reading rule to the reader.
1459    template <typename Map>
1460    GraphReader& arcMap(const std::string& caption, Map& map) {
1461      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1462      _reader_bits::MapStorageBase<Edge>* forward_storage =
1463        new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
1464      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1465      _reader_bits::MapStorageBase<Edge>* backward_storage =
1466        new _reader_bits::GraphArcMapStorage<Graph, false, Map>(_graph, map);
1467      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1468      return *this;
1469    }
1470
1471    /// \brief Arc map reading rule
1472    ///
1473    /// Add an arc map reading rule with specialized converter to the
1474    /// reader.
1475    template <typename Map, typename Converter>
1476    GraphReader& arcMap(const std::string& caption, Map& map,
1477                          const Converter& converter = Converter()) {
1478      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1479      _reader_bits::MapStorageBase<Edge>* forward_storage =
1480        new _reader_bits::GraphArcMapStorage<Graph, true, Map, Converter>
1481        (_graph, map, converter);
1482      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1483      _reader_bits::MapStorageBase<Edge>* backward_storage =
1484        new _reader_bits::GraphArcMapStorage<Graph, false, Map, Converter>
1485        (_graph, map, converter);
1486      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1487      return *this;
1488    }
1489
1490    /// \brief Attribute reading rule
1491    ///
1492    /// Add an attribute reading rule to the reader.
1493    template <typename Value>
1494    GraphReader& attribute(const std::string& caption, Value& value) {
1495      _reader_bits::ValueStorageBase* storage =
1496        new _reader_bits::ValueStorage<Value>(value);
1497      _attributes.insert(std::make_pair(caption, storage));
1498      return *this;
1499    }
1500
1501    /// \brief Attribute reading rule
1502    ///
1503    /// Add an attribute reading rule with specialized converter to the
1504    /// reader.
1505    template <typename Value, typename Converter>
1506    GraphReader& attribute(const std::string& caption, Value& value,
1507                             const Converter& converter = Converter()) {
1508      _reader_bits::ValueStorageBase* storage =
1509        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
1510      _attributes.insert(std::make_pair(caption, storage));
1511      return *this;
1512    }
1513
1514    /// \brief Node reading rule
1515    ///
1516    /// Add a node reading rule to reader.
1517    GraphReader& node(const std::string& caption, Node& node) {
1518      typedef _reader_bits::MapLookUpConverter<Node> Converter;
1519      Converter converter(_node_index);
1520      _reader_bits::ValueStorageBase* storage =
1521        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
1522      _attributes.insert(std::make_pair(caption, storage));
1523      return *this;
1524    }
1525
1526    /// \brief Edge reading rule
1527    ///
1528    /// Add an edge reading rule to reader.
1529    GraphReader& edge(const std::string& caption, Edge& edge) {
1530      typedef _reader_bits::MapLookUpConverter<Edge> Converter;
1531      Converter converter(_edge_index);
1532      _reader_bits::ValueStorageBase* storage =
1533        new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
1534      _attributes.insert(std::make_pair(caption, storage));
1535      return *this;
1536    }
1537
1538    /// \brief Arc reading rule
1539    ///
1540    /// Add an arc reading rule to reader.
1541    GraphReader& arc(const std::string& caption, Arc& arc) {
1542      typedef _reader_bits::GraphArcLookUpConverter<Graph> Converter;
1543      Converter converter(_graph, _edge_index);
1544      _reader_bits::ValueStorageBase* storage =
1545        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
1546      _attributes.insert(std::make_pair(caption, storage));
1547      return *this;
1548    }
1549
1550    /// @}
1551
1552    /// \name Select section by name
1553    /// @{
1554
1555    /// \brief Set \c \@nodes section to be read
1556    ///
1557    /// Set \c \@nodes section to be read.
1558    GraphReader& nodes(const std::string& caption) {
1559      _nodes_caption = caption;
1560      return *this;
1561    }
1562
1563    /// \brief Set \c \@edges section to be read
1564    ///
1565    /// Set \c \@edges section to be read.
1566    GraphReader& edges(const std::string& caption) {
1567      _edges_caption = caption;
1568      return *this;
1569    }
1570
1571    /// \brief Set \c \@attributes section to be read
1572    ///
1573    /// Set \c \@attributes section to be read.
1574    GraphReader& attributes(const std::string& caption) {
1575      _attributes_caption = caption;
1576      return *this;
1577    }
1578
1579    /// @}
1580
1581    /// \name Using previously constructed node or edge set
1582    /// @{
1583
1584    /// \brief Use previously constructed node set
1585    ///
1586    /// Use previously constructed node set, and specify the node
1587    /// label map.
1588    template <typename Map>
1589    GraphReader& useNodes(const Map& map) {
1590      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1591      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1592      _use_nodes = true;
1593      _writer_bits::DefaultConverter<typename Map::Value> converter;
1594      for (NodeIt n(_graph); n != INVALID; ++n) {
1595        _node_index.insert(std::make_pair(converter(map[n]), n));
1596      }
1597      return *this;
1598    }
1599
1600    /// \brief Use previously constructed node set
1601    ///
1602    /// Use previously constructed node set, and specify the node
1603    /// label map and a functor which converts the label map values to
1604    /// \c std::string.
1605    template <typename Map, typename Converter>
1606    GraphReader& useNodes(const Map& map,
1607                            const Converter& converter = Converter()) {
1608      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1609      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1610      _use_nodes = true;
1611      for (NodeIt n(_graph); n != INVALID; ++n) {
1612        _node_index.insert(std::make_pair(converter(map[n]), n));
1613      }
1614      return *this;
1615    }
1616
1617    /// \brief Use previously constructed edge set
1618    ///
1619    /// Use previously constructed edge set, and specify the edge
1620    /// label map.
1621    template <typename Map>
1622    GraphReader& useEdges(const Map& map) {
1623      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1624      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1625      _use_edges = true;
1626      _writer_bits::DefaultConverter<typename Map::Value> converter;
1627      for (EdgeIt a(_graph); a != INVALID; ++a) {
1628        _edge_index.insert(std::make_pair(converter(map[a]), a));
1629      }
1630      return *this;
1631    }
1632
1633    /// \brief Use previously constructed edge set
1634    ///
1635    /// Use previously constructed edge set, and specify the edge
1636    /// label map and a functor which converts the label map values to
1637    /// \c std::string.
1638    template <typename Map, typename Converter>
1639    GraphReader& useEdges(const Map& map,
1640                            const Converter& converter = Converter()) {
1641      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1642      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1643      _use_edges = true;
1644      for (EdgeIt a(_graph); a != INVALID; ++a) {
1645        _edge_index.insert(std::make_pair(converter(map[a]), a));
1646      }
1647      return *this;
1648    }
1649
1650    /// \brief Skip the reading of node section
1651    ///
1652    /// Omit the reading of the node section. This implies that each node
1653    /// map reading rule will be abandoned, and the nodes of the graph
1654    /// will not be constructed, which usually cause that the edge set
1655    /// could not be read due to lack of node name
1656    /// could not be read due to lack of node name resolving.
1657    /// Therefore \c skipEdges() function should also be used, or
1658    /// \c useNodes() should be used to specify the label of the nodes.
1659    GraphReader& skipNodes() {
1660      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
1661      _skip_nodes = true;
1662      return *this;
1663    }
1664
1665    /// \brief Skip the reading of edge section
1666    ///
1667    /// Omit the reading of the edge section. This implies that each edge
1668    /// map reading rule will be abandoned, and the edges of the graph
1669    /// will not be constructed.
1670    GraphReader& skipEdges() {
1671      LEMON_ASSERT(!_skip_edges, "Skip edges already set");
1672      _skip_edges = true;
1673      return *this;
1674    }
1675
1676    /// @}
1677
1678  private:
1679
1680    bool readLine() {
1681      std::string str;
1682      while(++line_num, std::getline(*_is, str)) {
1683        line.clear(); line.str(str);
1684        char c;
1685        if (line >> std::ws >> c && c != '#') {
1686          line.putback(c);
1687          return true;
1688        }
1689      }
1690      return false;
1691    }
1692
1693    bool readSuccess() {
1694      return static_cast<bool>(*_is);
1695    }
1696
1697    void skipSection() {
1698      char c;
1699      while (readSuccess() && line >> c && c != '@') {
1700        readLine();
1701      }
1702      line.putback(c);
1703    }
1704
1705    void readNodes() {
1706
1707      std::vector<int> map_index(_node_maps.size());
1708      int map_num, label_index;
1709
1710      char c;
1711      if (!readLine() || !(line >> c) || c == '@') {
1712        if (readSuccess() && line) line.putback(c);
1713        if (!_node_maps.empty())
1714          throw FormatError("Cannot find map names");
1715        return;
1716      }
1717      line.putback(c);
1718
1719      {
1720        std::map<std::string, int> maps;
1721
1722        std::string map;
1723        int index = 0;
1724        while (_reader_bits::readToken(line, map)) {
1725          if (maps.find(map) != maps.end()) {
1726            std::ostringstream msg;
1727            msg << "Multiple occurence of node map: " << map;
1728            throw FormatError(msg.str());
1729          }
1730          maps.insert(std::make_pair(map, index));
1731          ++index;
1732        }
1733
1734        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1735          std::map<std::string, int>::iterator jt =
1736            maps.find(_node_maps[i].first);
1737          if (jt == maps.end()) {
1738            std::ostringstream msg;
1739            msg << "Map not found: " << _node_maps[i].first;
1740            throw FormatError(msg.str());
1741          }
1742          map_index[i] = jt->second;
1743        }
1744
1745        {
1746          std::map<std::string, int>::iterator jt = maps.find("label");
1747          if (jt != maps.end()) {
1748            label_index = jt->second;
1749          } else {
1750            label_index = -1;
1751          }
1752        }
1753        map_num = maps.size();
1754      }
1755
1756      while (readLine() && line >> c && c != '@') {
1757        line.putback(c);
1758
1759        std::vector<std::string> tokens(map_num);
1760        for (int i = 0; i < map_num; ++i) {
1761          if (!_reader_bits::readToken(line, tokens[i])) {
1762            std::ostringstream msg;
1763            msg << "Column not found (" << i + 1 << ")";
1764            throw FormatError(msg.str());
1765          }
1766        }
1767        if (line >> std::ws >> c)
1768          throw FormatError("Extra character at the end of line");
1769
1770        Node n;
1771        if (!_use_nodes) {
1772          n = _graph.addNode();
1773          if (label_index != -1)
1774            _node_index.insert(std::make_pair(tokens[label_index], n));
1775        } else {
1776          if (label_index == -1)
1777            throw FormatError("Label map not found");
1778          typename std::map<std::string, Node>::iterator it =
1779            _node_index.find(tokens[label_index]);
1780          if (it == _node_index.end()) {
1781            std::ostringstream msg;
1782            msg << "Node with label not found: " << tokens[label_index];
1783            throw FormatError(msg.str());
1784          }
1785          n = it->second;
1786        }
1787
1788        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1789          _node_maps[i].second->set(n, tokens[map_index[i]]);
1790        }
1791
1792      }
1793      if (readSuccess()) {
1794        line.putback(c);
1795      }
1796    }
1797
1798    void readEdges() {
1799
1800      std::vector<int> map_index(_edge_maps.size());
1801      int map_num, label_index;
1802
1803      char c;
1804      if (!readLine() || !(line >> c) || c == '@') {
1805        if (readSuccess() && line) line.putback(c);
1806        if (!_edge_maps.empty())
1807          throw FormatError("Cannot find map names");
1808        return;
1809      }
1810      line.putback(c);
1811
1812      {
1813        std::map<std::string, int> maps;
1814
1815        std::string map;
1816        int index = 0;
1817        while (_reader_bits::readToken(line, map)) {
1818          if (maps.find(map) != maps.end()) {
1819            std::ostringstream msg;
1820            msg << "Multiple occurence of edge map: " << map;
1821            throw FormatError(msg.str());
1822          }
1823          maps.insert(std::make_pair(map, index));
1824          ++index;
1825        }
1826
1827        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1828          std::map<std::string, int>::iterator jt =
1829            maps.find(_edge_maps[i].first);
1830          if (jt == maps.end()) {
1831            std::ostringstream msg;
1832            msg << "Map not found: " << _edge_maps[i].first;
1833            throw FormatError(msg.str());
1834          }
1835          map_index[i] = jt->second;
1836        }
1837
1838        {
1839          std::map<std::string, int>::iterator jt = maps.find("label");
1840          if (jt != maps.end()) {
1841            label_index = jt->second;
1842          } else {
1843            label_index = -1;
1844          }
1845        }
1846        map_num = maps.size();
1847      }
1848
1849      while (readLine() && line >> c && c != '@') {
1850        line.putback(c);
1851
1852        std::string source_token;
1853        std::string target_token;
1854
1855        if (!_reader_bits::readToken(line, source_token))
1856          throw FormatError("Node u not found");
1857
1858        if (!_reader_bits::readToken(line, target_token))
1859          throw FormatError("Node v not found");
1860
1861        std::vector<std::string> tokens(map_num);
1862        for (int i = 0; i < map_num; ++i) {
1863          if (!_reader_bits::readToken(line, tokens[i])) {
1864            std::ostringstream msg;
1865            msg << "Column not found (" << i + 1 << ")";
1866            throw FormatError(msg.str());
1867          }
1868        }
1869        if (line >> std::ws >> c)
1870          throw FormatError("Extra character at the end of line");
1871
1872        Edge e;
1873        if (!_use_edges) {
1874
1875          typename NodeIndex::iterator it;
1876
1877          it = _node_index.find(source_token);
1878          if (it == _node_index.end()) {
1879            std::ostringstream msg;
1880            msg << "Item not found: " << source_token;
1881            throw FormatError(msg.str());
1882          }
1883          Node source = it->second;
1884
1885          it = _node_index.find(target_token);
1886          if (it == _node_index.end()) {
1887            std::ostringstream msg;
1888            msg << "Item not found: " << target_token;
1889            throw FormatError(msg.str());
1890          }
1891          Node target = it->second;
1892
1893          e = _graph.addEdge(source, target);
1894          if (label_index != -1)
1895            _edge_index.insert(std::make_pair(tokens[label_index], e));
1896        } else {
1897          if (label_index == -1)
1898            throw FormatError("Label map not found");
1899          typename std::map<std::string, Edge>::iterator it =
1900            _edge_index.find(tokens[label_index]);
1901          if (it == _edge_index.end()) {
1902            std::ostringstream msg;
1903            msg << "Edge with label not found: " << tokens[label_index];
1904            throw FormatError(msg.str());
1905          }
1906          e = it->second;
1907        }
1908
1909        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1910          _edge_maps[i].second->set(e, tokens[map_index[i]]);
1911        }
1912
1913      }
1914      if (readSuccess()) {
1915        line.putback(c);
1916      }
1917    }
1918
1919    void readAttributes() {
1920
1921      std::set<std::string> read_attr;
1922
1923      char c;
1924      while (readLine() && line >> c && c != '@') {
1925        line.putback(c);
1926
1927        std::string attr, token;
1928        if (!_reader_bits::readToken(line, attr))
1929          throw FormatError("Attribute name not found");
1930        if (!_reader_bits::readToken(line, token))
1931          throw FormatError("Attribute value not found");
1932        if (line >> c)
1933          throw FormatError("Extra character at the end of line");
1934
1935        {
1936          std::set<std::string>::iterator it = read_attr.find(attr);
1937          if (it != read_attr.end()) {
1938            std::ostringstream msg;
1939            msg << "Multiple occurence of attribute: " << attr;
1940            throw FormatError(msg.str());
1941          }
1942          read_attr.insert(attr);
1943        }
1944
1945        {
1946          typename Attributes::iterator it = _attributes.lower_bound(attr);
1947          while (it != _attributes.end() && it->first == attr) {
1948            it->second->set(token);
1949            ++it;
1950          }
1951        }
1952
1953      }
1954      if (readSuccess()) {
1955        line.putback(c);
1956      }
1957      for (typename Attributes::iterator it = _attributes.begin();
1958           it != _attributes.end(); ++it) {
1959        if (read_attr.find(it->first) == read_attr.end()) {
1960          std::ostringstream msg;
1961          msg << "Attribute not found: " << it->first;
1962          throw FormatError(msg.str());
1963        }
1964      }
1965    }
1966
1967  public:
1968
1969    /// \name Execution of the reader
1970    /// @{
1971
1972    /// \brief Start the batch processing
1973    ///
1974    /// This function starts the batch processing
1975    void run() {
1976
1977      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1978
1979      bool nodes_done = _skip_nodes;
1980      bool edges_done = _skip_edges;
1981      bool attributes_done = false;
1982
1983      line_num = 0;
1984      readLine();
1985      skipSection();
1986
1987      while (readSuccess()) {
1988        try {
1989          char c;
1990          std::string section, caption;
1991          line >> c;
1992          _reader_bits::readToken(line, section);
1993          _reader_bits::readToken(line, caption);
1994
1995          if (line >> c)
1996            throw FormatError("Extra character at the end of line");
1997
1998          if (section == "nodes" && !nodes_done) {
1999            if (_nodes_caption.empty() || _nodes_caption == caption) {
2000              readNodes();
2001              nodes_done = true;
2002            }
2003          } else if ((section == "edges" || section == "arcs") &&
2004                     !edges_done) {
2005            if (_edges_caption.empty() || _edges_caption == caption) {
2006              readEdges();
2007              edges_done = true;
2008            }
2009          } else if (section == "attributes" && !attributes_done) {
2010            if (_attributes_caption.empty() || _attributes_caption == caption) {
2011              readAttributes();
2012              attributes_done = true;
2013            }
2014          } else {
2015            readLine();
2016            skipSection();
2017          }
2018        } catch (FormatError& error) {
2019          error.line(line_num);
2020          error.file(_filename);
2021          throw;
2022        }
2023      }
2024
2025      if (!nodes_done) {
2026        throw FormatError("Section @nodes not found");
2027      }
2028
2029      if (!edges_done) {
2030        throw FormatError("Section @edges not found");
2031      }
2032
2033      if (!attributes_done && !_attributes.empty()) {
2034        throw FormatError("Section @attributes not found");
2035      }
2036
2037    }
2038
2039    /// @}
2040
2041  };
2042
2043  class SectionReader;
2044
2045  SectionReader sectionReader(std::istream& is);
2046  SectionReader sectionReader(const std::string& fn);
2047  SectionReader sectionReader(const char* fn);
2048
2049  /// \ingroup lemon_io
2050  ///
2051  /// \brief Section reader class
2052  ///
2053  /// In the \ref lgf-format "LGF" file extra sections can be placed,
2054  /// which contain any data in arbitrary format. Such sections can be
2055  /// read with this class. A reading rule can be added to the class
2056  /// with two different functions. With the \c sectionLines() function a
2057  /// functor can process the section line-by-line, while with the \c
2058  /// sectionStream() member the section can be read from an input
2059  /// stream.
2060  class SectionReader {
2061  private:
2062
2063    std::istream* _is;
2064    bool local_is;
2065    std::string _filename;
2066
2067    typedef std::map<std::string, _reader_bits::Section*> Sections;
2068    Sections _sections;
2069
2070    int line_num;
2071    std::istringstream line;
2072
2073  public:
2074
2075    /// \brief Constructor
2076    ///
2077    /// Construct a section reader, which reads from the given input
2078    /// stream.
2079    SectionReader(std::istream& is)
2080      : _is(&is), local_is(false) {}
2081
2082    /// \brief Constructor
2083    ///
2084    /// Construct a section reader, which reads from the given file.
2085    SectionReader(const std::string& fn)
2086      : _is(new std::ifstream(fn.c_str())), local_is(true),
2087        _filename(fn) {
2088      if (!(*_is)) {
2089        delete _is;
2090        throw IoError("Cannot open file", fn);
2091      }
2092    }
2093
2094    /// \brief Constructor
2095    ///
2096    /// Construct a section reader, which reads from the given file.
2097    SectionReader(const char* fn)
2098      : _is(new std::ifstream(fn)), local_is(true),
2099        _filename(fn) {
2100      if (!(*_is)) {
2101        delete _is;
2102        throw IoError("Cannot open file", fn);
2103      }
2104    }
2105
2106    /// \brief Destructor
2107    ~SectionReader() {
2108      for (Sections::iterator it = _sections.begin();
2109           it != _sections.end(); ++it) {
2110        delete it->second;
2111      }
2112
2113      if (local_is) {
2114        delete _is;
2115      }
2116
2117    }
2118
2119  private:
2120
2121    friend SectionReader sectionReader(std::istream& is);
2122    friend SectionReader sectionReader(const std::string& fn);
2123    friend SectionReader sectionReader(const char* fn);
2124
2125    SectionReader(SectionReader& other)
2126      : _is(other._is), local_is(other.local_is) {
2127
2128      other._is = 0;
2129      other.local_is = false;
2130
2131      _sections.swap(other._sections);
2132    }
2133
2134    SectionReader& operator=(const SectionReader&);
2135
2136  public:
2137
2138    /// \name Section readers
2139    /// @{
2140
2141    /// \brief Add a section processor with line oriented reading
2142    ///
2143    /// The first parameter is the type descriptor of the section, the
2144    /// second is a functor, which takes just one \c std::string
2145    /// parameter. At the reading process, each line of the section
2146    /// will be given to the functor object. However, the empty lines
2147    /// and the comment lines are filtered out, and the leading
2148    /// whitespaces are trimmed from each processed string.
2149    ///
2150    /// For example let's see a section, which contain several
2151    /// integers, which should be inserted into a vector.
2152    ///\code
2153    ///  @numbers
2154    ///  12 45 23
2155    ///  4
2156    ///  23 6
2157    ///\endcode
2158    ///
2159    /// The functor is implemented as a struct:
2160    ///\code
2161    ///  struct NumberSection {
2162    ///    std::vector<int>& _data;
2163    ///    NumberSection(std::vector<int>& data) : _data(data) {}
2164    ///    void operator()(const std::string& line) {
2165    ///      std::istringstream ls(line);
2166    ///      int value;
2167    ///      while (ls >> value) _data.push_back(value);
2168    ///    }
2169    ///  };
2170    ///
2171    ///  // ...
2172    ///
2173    ///  reader.sectionLines("numbers", NumberSection(vec));
2174    ///\endcode
2175    template <typename Functor>
2176    SectionReader& sectionLines(const std::string& type, Functor functor) {
2177      LEMON_ASSERT(!type.empty(), "Type is empty.");
2178      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2179                   "Multiple reading of section.");
2180      _sections.insert(std::make_pair(type,
2181        new _reader_bits::LineSection<Functor>(functor)));
2182      return *this;
2183    }
2184
2185
2186    /// \brief Add a section processor with stream oriented reading
2187    ///
2188    /// The first parameter is the type of the section, the second is
2189    /// a functor, which takes an \c std::istream& and an \c int&
2190    /// parameter, the latter regard to the line number of stream. The
2191    /// functor can read the input while the section go on, and the
2192    /// line number should be modified accordingly.
2193    template <typename Functor>
2194    SectionReader& sectionStream(const std::string& type, Functor functor) {
2195      LEMON_ASSERT(!type.empty(), "Type is empty.");
2196      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2197                   "Multiple reading of section.");
2198      _sections.insert(std::make_pair(type,
2199         new _reader_bits::StreamSection<Functor>(functor)));
2200      return *this;
2201    }
2202
2203    /// @}
2204
2205  private:
2206
2207    bool readLine() {
2208      std::string str;
2209      while(++line_num, std::getline(*_is, str)) {
2210        line.clear(); line.str(str);
2211        char c;
2212        if (line >> std::ws >> c && c != '#') {
2213          line.putback(c);
2214          return true;
2215        }
2216      }
2217      return false;
2218    }
2219
2220    bool readSuccess() {
2221      return static_cast<bool>(*_is);
2222    }
2223
2224    void skipSection() {
2225      char c;
2226      while (readSuccess() && line >> c && c != '@') {
2227        readLine();
2228      }
2229      line.putback(c);
2230    }
2231
2232  public:
2233
2234
2235    /// \name Execution of the reader
2236    /// @{
2237
2238    /// \brief Start the batch processing
2239    ///
2240    /// This function starts the batch processing.
2241    void run() {
2242
2243      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
2244
2245      std::set<std::string> extra_sections;
2246
2247      line_num = 0;
2248      readLine();
2249      skipSection();
2250
2251      while (readSuccess()) {
2252        try {
2253          char c;
2254          std::string section, caption;
2255          line >> c;
2256          _reader_bits::readToken(line, section);
2257          _reader_bits::readToken(line, caption);
2258
2259          if (line >> c)
2260            throw FormatError("Extra character at the end of line");
2261
2262          if (extra_sections.find(section) != extra_sections.end()) {
2263            std::ostringstream msg;
2264            msg << "Multiple occurence of section: " << section;
2265            throw FormatError(msg.str());
2266          }
2267          Sections::iterator it = _sections.find(section);
2268          if (it != _sections.end()) {
2269            extra_sections.insert(section);
2270            it->second->process(*_is, line_num);
2271          }
2272          readLine();
2273          skipSection();
2274        } catch (FormatError& error) {
2275          error.line(line_num);
2276          error.file(_filename);
2277          throw;
2278        }
2279      }
2280      for (Sections::iterator it = _sections.begin();
2281           it != _sections.end(); ++it) {
2282        if (extra_sections.find(it->first) == extra_sections.end()) {
2283          std::ostringstream os;
2284          os << "Cannot find section: " << it->first;
2285          throw FormatError(os.str());
2286        }
2287      }
2288    }
2289
2290    /// @}
2291
2292  };
2293
2294  /// \brief Return a \ref SectionReader class
2295  ///
2296  /// This function just returns a \ref SectionReader class.
2297  /// \relates SectionReader
2298  inline SectionReader sectionReader(std::istream& is) {
2299    SectionReader tmp(is);
2300    return tmp;
2301  }
2302
2303  /// \brief Return a \ref SectionReader class
2304  ///
2305  /// This function just returns a \ref SectionReader class.
2306  /// \relates SectionReader
2307  inline SectionReader sectionReader(const std::string& fn) {
2308    SectionReader tmp(fn);
2309    return tmp;
2310  }
2311
2312  /// \brief Return a \ref SectionReader class
2313  ///
2314  /// This function just returns a \ref SectionReader class.
2315  /// \relates SectionReader
2316  inline SectionReader sectionReader(const char* fn) {
2317    SectionReader tmp(fn);
2318    return tmp;
2319  }
2320
2321  /// \ingroup lemon_io
2322  ///
2323  /// \brief Reader for the contents of the \ref lgf-format "LGF" file
2324  ///
2325  /// This class can be used to read the sections, the map names and
2326  /// the attributes from a file. Usually, the LEMON programs know
2327  /// that, which type of graph, which maps and which attributes
2328  /// should be read from a file, but in general tools (like glemon)
2329  /// the contents of an LGF file should be guessed somehow. This class
2330  /// reads the graph and stores the appropriate information for
2331  /// reading the graph.
2332  ///
2333  ///\code
2334  /// LgfContents contents("graph.lgf");
2335  /// contents.run();
2336  ///
2337  /// // Does it contain any node section and arc section?
2338  /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
2339  ///   std::cerr << "Failure, cannot find graph." << std::endl;
2340  ///   return -1;
2341  /// }
2342  /// std::cout << "The name of the default node section: "
2343  ///           << contents.nodeSection(0) << std::endl;
2344  /// std::cout << "The number of the arc maps: "
2345  ///           << contents.arcMaps(0).size() << std::endl;
2346  /// std::cout << "The name of second arc map: "
2347  ///           << contents.arcMaps(0)[1] << std::endl;
2348  ///\endcode
2349  class LgfContents {
2350  private:
2351
2352    std::istream* _is;
2353    bool local_is;
2354
2355    std::vector<std::string> _node_sections;
2356    std::vector<std::string> _edge_sections;
2357    std::vector<std::string> _attribute_sections;
2358    std::vector<std::string> _extra_sections;
2359
2360    std::vector<bool> _arc_sections;
2361
2362    std::vector<std::vector<std::string> > _node_maps;
2363    std::vector<std::vector<std::string> > _edge_maps;
2364
2365    std::vector<std::vector<std::string> > _attributes;
2366
2367
2368    int line_num;
2369    std::istringstream line;
2370
2371  public:
2372
2373    /// \brief Constructor
2374    ///
2375    /// Construct an \e LGF contents reader, which reads from the given
2376    /// input stream.
2377    LgfContents(std::istream& is)
2378      : _is(&is), local_is(false) {}
2379
2380    /// \brief Constructor
2381    ///
2382    /// Construct an \e LGF contents reader, which reads from the given
2383    /// file.
2384    LgfContents(const std::string& fn)
2385      : _is(new std::ifstream(fn.c_str())), local_is(true) {
2386      if (!(*_is)) {
2387        delete _is;
2388        throw IoError("Cannot open file", fn);
2389      }
2390    }
2391
2392    /// \brief Constructor
2393    ///
2394    /// Construct an \e LGF contents reader, which reads from the given
2395    /// file.
2396    LgfContents(const char* fn)
2397      : _is(new std::ifstream(fn)), local_is(true) {
2398      if (!(*_is)) {
2399        delete _is;
2400        throw IoError("Cannot open file", fn);
2401      }
2402    }
2403
2404    /// \brief Destructor
2405    ~LgfContents() {
2406      if (local_is) delete _is;
2407    }
2408
2409  private:
2410
2411    LgfContents(const LgfContents&);
2412    LgfContents& operator=(const LgfContents&);
2413
2414  public:
2415
2416
2417    /// \name Node sections
2418    /// @{
2419
2420    /// \brief Gives back the number of node sections in the file.
2421    ///
2422    /// Gives back the number of node sections in the file.
2423    int nodeSectionNum() const {
2424      return _node_sections.size();
2425    }
2426
2427    /// \brief Returns the node section name at the given position.
2428    ///
2429    /// Returns the node section name at the given position.
2430    const std::string& nodeSection(int i) const {
2431      return _node_sections[i];
2432    }
2433
2434    /// \brief Gives back the node maps for the given section.
2435    ///
2436    /// Gives back the node maps for the given section.
2437    const std::vector<std::string>& nodeMapNames(int i) const {
2438      return _node_maps[i];
2439    }
2440
2441    /// @}
2442
2443    /// \name Arc/Edge sections
2444    /// @{
2445
2446    /// \brief Gives back the number of arc/edge sections in the file.
2447    ///
2448    /// Gives back the number of arc/edge sections in the file.
2449    /// \note It is synonym of \c edgeSectionNum().
2450    int arcSectionNum() const {
2451      return _edge_sections.size();
2452    }
2453
2454    /// \brief Returns the arc/edge section name at the given position.
2455    ///
2456    /// Returns the arc/edge section name at the given position.
2457    /// \note It is synonym of \c edgeSection().
2458    const std::string& arcSection(int i) const {
2459      return _edge_sections[i];
2460    }
2461
2462    /// \brief Gives back the arc/edge maps for the given section.
2463    ///
2464    /// Gives back the arc/edge maps for the given section.
2465    /// \note It is synonym of \c edgeMapNames().
2466    const std::vector<std::string>& arcMapNames(int i) const {
2467      return _edge_maps[i];
2468    }
2469
2470    /// @}
2471
2472    /// \name Synonyms
2473    /// @{
2474
2475    /// \brief Gives back the number of arc/edge sections in the file.
2476    ///
2477    /// Gives back the number of arc/edge sections in the file.
2478    /// \note It is synonym of \c arcSectionNum().
2479    int edgeSectionNum() const {
2480      return _edge_sections.size();
2481    }
2482
2483    /// \brief Returns the section name at the given position.
2484    ///
2485    /// Returns the section name at the given position.
2486    /// \note It is synonym of \c arcSection().
2487    const std::string& edgeSection(int i) const {
2488      return _edge_sections[i];
2489    }
2490
2491    /// \brief Gives back the edge maps for the given section.
2492    ///
2493    /// Gives back the edge maps for the given section.
2494    /// \note It is synonym of \c arcMapNames().
2495    const std::vector<std::string>& edgeMapNames(int i) const {
2496      return _edge_maps[i];
2497    }
2498
2499    /// @}
2500
2501    /// \name Attribute sections
2502    /// @{
2503
2504    /// \brief Gives back the number of attribute sections in the file.
2505    ///
2506    /// Gives back the number of attribute sections in the file.
2507    int attributeSectionNum() const {
2508      return _attribute_sections.size();
2509    }
2510
2511    /// \brief Returns the attribute section name at the given position.
2512    ///
2513    /// Returns the attribute section name at the given position.
2514    const std::string& attributeSectionNames(int i) const {
2515      return _attribute_sections[i];
2516    }
2517
2518    /// \brief Gives back the attributes for the given section.
2519    ///
2520    /// Gives back the attributes for the given section.
2521    const std::vector<std::string>& attributes(int i) const {
2522      return _attributes[i];
2523    }
2524
2525    /// @}
2526
2527    /// \name Extra sections
2528    /// @{
2529
2530    /// \brief Gives back the number of extra sections in the file.
2531    ///
2532    /// Gives back the number of extra sections in the file.
2533    int extraSectionNum() const {
2534      return _extra_sections.size();
2535    }
2536
2537    /// \brief Returns the extra section type at the given position.
2538    ///
2539    /// Returns the section type at the given position.
2540    const std::string& extraSection(int i) const {
2541      return _extra_sections[i];
2542    }
2543
2544    /// @}
2545
2546  private:
2547
2548    bool readLine() {
2549      std::string str;
2550      while(++line_num, std::getline(*_is, str)) {
2551        line.clear(); line.str(str);
2552        char c;
2553        if (line >> std::ws >> c && c != '#') {
2554          line.putback(c);
2555          return true;
2556        }
2557      }
2558      return false;
2559    }
2560
2561    bool readSuccess() {
2562      return static_cast<bool>(*_is);
2563    }
2564
2565    void skipSection() {
2566      char c;
2567      while (readSuccess() && line >> c && c != '@') {
2568        readLine();
2569      }
2570      line.putback(c);
2571    }
2572
2573    void readMaps(std::vector<std::string>& maps) {
2574      char c;
2575      if (!readLine() || !(line >> c) || c == '@') {
2576        if (readSuccess() && line) line.putback(c);
2577        return;
2578      }
2579      line.putback(c);
2580      std::string map;
2581      while (_reader_bits::readToken(line, map)) {
2582        maps.push_back(map);
2583      }
2584    }
2585
2586    void readAttributes(std::vector<std::string>& attrs) {
2587      readLine();
2588      char c;
2589      while (readSuccess() && line >> c && c != '@') {
2590        line.putback(c);
2591        std::string attr;
2592        _reader_bits::readToken(line, attr);
2593        attrs.push_back(attr);
2594        readLine();
2595      }
2596      line.putback(c);
2597    }
2598
2599  public:
2600
2601    /// \name Execution of the contents reader
2602    /// @{
2603
2604    /// \brief Starts the reading
2605    ///
2606    /// This function starts the reading.
2607    void run() {
2608
2609      readLine();
2610      skipSection();
2611
2612      while (readSuccess()) {
2613
2614        char c;
2615        line >> c;
2616
2617        std::string section, caption;
2618        _reader_bits::readToken(line, section);
2619        _reader_bits::readToken(line, caption);
2620
2621        if (section == "nodes") {
2622          _node_sections.push_back(caption);
2623          _node_maps.push_back(std::vector<std::string>());
2624          readMaps(_node_maps.back());
2625          readLine(); skipSection();
2626        } else if (section == "arcs" || section == "edges") {
2627          _edge_sections.push_back(caption);
2628          _arc_sections.push_back(section == "arcs");
2629          _edge_maps.push_back(std::vector<std::string>());
2630          readMaps(_edge_maps.back());
2631          readLine(); skipSection();
2632        } else if (section == "attributes") {
2633          _attribute_sections.push_back(caption);
2634          _attributes.push_back(std::vector<std::string>());
2635          readAttributes(_attributes.back());
2636        } else {
2637          _extra_sections.push_back(section);
2638          readLine(); skipSection();
2639        }
2640      }
2641    }
2642
2643    /// @}
2644
2645  };
2646}
2647
2648#endif
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