COIN-OR::LEMON - Graph Library

source: lemon/lemon/lgf_reader.h @ 564:2b6d5d22bb23

Last change on this file since 564:2b6d5d22bb23 was 564:2b6d5d22bb23, checked in by Alpar Juttner <alpar@…>, 11 years ago

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1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2009
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  template <typename Digraph>
394  DigraphReader<Digraph> digraphReader(Digraph& digraph,
395                                       std::istream& is = std::cin);
396  template <typename Digraph>
397  DigraphReader<Digraph> digraphReader(Digraph& digraph, const std::string& fn);
398  template <typename Digraph>
399  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char *fn);
400
401  /// \ingroup lemon_io
402  ///
403  /// \brief \ref lgf-format "LGF" reader for directed graphs
404  ///
405  /// This utility reads an \ref lgf-format "LGF" file.
406  ///
407  /// The reading method does a batch processing. The user creates a
408  /// reader object, then various reading rules can be added to the
409  /// reader, and eventually the reading is executed with the \c run()
410  /// member function. A map reading rule can be added to the reader
411  /// with the \c nodeMap() or \c arcMap() members. An optional
412  /// converter parameter can also be added as a standard functor
413  /// converting from \c std::string to the value type of the map. If it
414  /// is set, it will determine how the tokens in the file should be
415  /// converted to the value type of the map. If the functor is not set,
416  /// then a default conversion will be used. One map can be read into
417  /// multiple map objects at the same time. The \c attribute(), \c
418  /// node() and \c arc() functions are used to add attribute reading
419  /// rules.
420  ///
421  ///\code
422  /// DigraphReader<Digraph>(digraph, std::cin).
423  ///   nodeMap("coordinates", coord_map).
424  ///   arcMap("capacity", cap_map).
425  ///   node("source", src).
426  ///   node("target", trg).
427  ///   attribute("caption", caption).
428  ///   run();
429  ///\endcode
430  ///
431  /// By default the reader uses the first section in the file of the
432  /// proper type. If a section has an optional name, then it can be
433  /// selected for reading by giving an optional name parameter to the
434  /// \c nodes(), \c arcs() or \c attributes() functions.
435  ///
436  /// The \c useNodes() and \c useArcs() functions are used to tell the reader
437  /// that the nodes or arcs should not be constructed (added to the
438  /// graph) during the reading, but instead the label map of the items
439  /// are given as a parameter of these functions. An
440  /// application of these functions is multipass reading, which is
441  /// important if two \c \@arcs sections must be read from the
442  /// file. In this case the first phase would read the node set and one
443  /// of the arc sets, while the second phase would read the second arc
444  /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
445  /// The previously read label node map should be passed to the \c
446  /// useNodes() functions. Another application of multipass reading when
447  /// paths are given as a node map or an arc map.
448  /// It is impossible to read this in
449  /// a single pass, because the arcs are not constructed when the node
450  /// maps are read.
451  template <typename _Digraph>
452  class DigraphReader {
453  public:
454
455    typedef _Digraph Digraph;
456    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
457
458  private:
459
460
461    std::istream* _is;
462    bool local_is;
463    std::string _filename;
464
465    Digraph& _digraph;
466
467    std::string _nodes_caption;
468    std::string _arcs_caption;
469    std::string _attributes_caption;
470
471    typedef std::map<std::string, Node> NodeIndex;
472    NodeIndex _node_index;
473    typedef std::map<std::string, Arc> ArcIndex;
474    ArcIndex _arc_index;
475
476    typedef std::vector<std::pair<std::string,
477      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
478    NodeMaps _node_maps;
479
480    typedef std::vector<std::pair<std::string,
481      _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
482    ArcMaps _arc_maps;
483
484    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
485      Attributes;
486    Attributes _attributes;
487
488    bool _use_nodes;
489    bool _use_arcs;
490
491    bool _skip_nodes;
492    bool _skip_arcs;
493
494    int line_num;
495    std::istringstream line;
496
497  public:
498
499    /// \brief Constructor
500    ///
501    /// Construct a directed graph reader, which reads from the given
502    /// input stream.
503    DigraphReader(Digraph& digraph, std::istream& is = std::cin)
504      : _is(&is), local_is(false), _digraph(digraph),
505        _use_nodes(false), _use_arcs(false),
506        _skip_nodes(false), _skip_arcs(false) {}
507
508    /// \brief Constructor
509    ///
510    /// Construct a directed graph reader, which reads from the given
511    /// file.
512    DigraphReader(Digraph& digraph, const std::string& fn)
513      : _is(new std::ifstream(fn.c_str())), local_is(true),
514        _filename(fn), _digraph(digraph),
515        _use_nodes(false), _use_arcs(false),
516        _skip_nodes(false), _skip_arcs(false) {
517      if (!(*_is)) {
518        delete _is;
519        throw IoError("Cannot open file", fn);
520      }
521    }
522
523    /// \brief Constructor
524    ///
525    /// Construct a directed graph reader, which reads from the given
526    /// file.
527    DigraphReader(Digraph& digraph, const char* fn)
528      : _is(new std::ifstream(fn)), local_is(true),
529        _filename(fn), _digraph(digraph),
530        _use_nodes(false), _use_arcs(false),
531        _skip_nodes(false), _skip_arcs(false) {
532      if (!(*_is)) {
533        delete _is;
534        throw IoError("Cannot open file", fn);
535      }
536    }
537
538    /// \brief Destructor
539    ~DigraphReader() {
540      for (typename NodeMaps::iterator it = _node_maps.begin();
541           it != _node_maps.end(); ++it) {
542        delete it->second;
543      }
544
545      for (typename ArcMaps::iterator it = _arc_maps.begin();
546           it != _arc_maps.end(); ++it) {
547        delete it->second;
548      }
549
550      for (typename Attributes::iterator it = _attributes.begin();
551           it != _attributes.end(); ++it) {
552        delete it->second;
553      }
554
555      if (local_is) {
556        delete _is;
557      }
558
559    }
560
561  private:
562
563    template <typename DGR>
564    friend DigraphReader<DGR> digraphReader(DGR& digraph, std::istream& is);
565    template <typename DGR>
566    friend DigraphReader<DGR> digraphReader(DGR& digraph,
567                                            const std::string& fn);
568    template <typename DGR>
569    friend DigraphReader<DGR> digraphReader(DGR& digraph, const char *fn);
570
571    DigraphReader(DigraphReader& other)
572      : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
573        _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
574        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
575
576      other._is = 0;
577      other.local_is = false;
578
579      _node_index.swap(other._node_index);
580      _arc_index.swap(other._arc_index);
581
582      _node_maps.swap(other._node_maps);
583      _arc_maps.swap(other._arc_maps);
584      _attributes.swap(other._attributes);
585
586      _nodes_caption = other._nodes_caption;
587      _arcs_caption = other._arcs_caption;
588      _attributes_caption = other._attributes_caption;
589
590    }
591
592    DigraphReader& operator=(const DigraphReader&);
593
594  public:
595
596    /// \name Reading rules
597    /// @{
598
599    /// \brief Node map reading rule
600    ///
601    /// Add a node map reading rule to the reader.
602    template <typename Map>
603    DigraphReader& nodeMap(const std::string& caption, Map& map) {
604      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
605      _reader_bits::MapStorageBase<Node>* storage =
606        new _reader_bits::MapStorage<Node, Map>(map);
607      _node_maps.push_back(std::make_pair(caption, storage));
608      return *this;
609    }
610
611    /// \brief Node map reading rule
612    ///
613    /// Add a node map reading rule with specialized converter to the
614    /// reader.
615    template <typename Map, typename Converter>
616    DigraphReader& nodeMap(const std::string& caption, Map& map,
617                           const Converter& converter = Converter()) {
618      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
619      _reader_bits::MapStorageBase<Node>* storage =
620        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
621      _node_maps.push_back(std::make_pair(caption, storage));
622      return *this;
623    }
624
625    /// \brief Arc map reading rule
626    ///
627    /// Add an arc map reading rule to the reader.
628    template <typename Map>
629    DigraphReader& arcMap(const std::string& caption, Map& map) {
630      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
631      _reader_bits::MapStorageBase<Arc>* storage =
632        new _reader_bits::MapStorage<Arc, Map>(map);
633      _arc_maps.push_back(std::make_pair(caption, storage));
634      return *this;
635    }
636
637    /// \brief Arc map reading rule
638    ///
639    /// Add an arc map reading rule with specialized converter to the
640    /// reader.
641    template <typename Map, typename Converter>
642    DigraphReader& arcMap(const std::string& caption, Map& map,
643                          const Converter& converter = Converter()) {
644      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
645      _reader_bits::MapStorageBase<Arc>* storage =
646        new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
647      _arc_maps.push_back(std::make_pair(caption, storage));
648      return *this;
649    }
650
651    /// \brief Attribute reading rule
652    ///
653    /// Add an attribute reading rule to the reader.
654    template <typename Value>
655    DigraphReader& attribute(const std::string& caption, Value& value) {
656      _reader_bits::ValueStorageBase* storage =
657        new _reader_bits::ValueStorage<Value>(value);
658      _attributes.insert(std::make_pair(caption, storage));
659      return *this;
660    }
661
662    /// \brief Attribute reading rule
663    ///
664    /// Add an attribute reading rule with specialized converter to the
665    /// reader.
666    template <typename Value, typename Converter>
667    DigraphReader& attribute(const std::string& caption, Value& value,
668                             const Converter& converter = Converter()) {
669      _reader_bits::ValueStorageBase* storage =
670        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
671      _attributes.insert(std::make_pair(caption, storage));
672      return *this;
673    }
674
675    /// \brief Node reading rule
676    ///
677    /// Add a node reading rule to reader.
678    DigraphReader& node(const std::string& caption, Node& node) {
679      typedef _reader_bits::MapLookUpConverter<Node> Converter;
680      Converter converter(_node_index);
681      _reader_bits::ValueStorageBase* storage =
682        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
683      _attributes.insert(std::make_pair(caption, storage));
684      return *this;
685    }
686
687    /// \brief Arc reading rule
688    ///
689    /// Add an arc reading rule to reader.
690    DigraphReader& arc(const std::string& caption, Arc& arc) {
691      typedef _reader_bits::MapLookUpConverter<Arc> Converter;
692      Converter converter(_arc_index);
693      _reader_bits::ValueStorageBase* storage =
694        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
695      _attributes.insert(std::make_pair(caption, storage));
696      return *this;
697    }
698
699    /// @}
700
701    /// \name Select section by name
702    /// @{
703
704    /// \brief Set \c \@nodes section to be read
705    ///
706    /// Set \c \@nodes section to be read
707    DigraphReader& nodes(const std::string& caption) {
708      _nodes_caption = caption;
709      return *this;
710    }
711
712    /// \brief Set \c \@arcs section to be read
713    ///
714    /// Set \c \@arcs section to be read
715    DigraphReader& arcs(const std::string& caption) {
716      _arcs_caption = caption;
717      return *this;
718    }
719
720    /// \brief Set \c \@attributes section to be read
721    ///
722    /// Set \c \@attributes section to be read
723    DigraphReader& attributes(const std::string& caption) {
724      _attributes_caption = caption;
725      return *this;
726    }
727
728    /// @}
729
730    /// \name Using previously constructed node or arc set
731    /// @{
732
733    /// \brief Use previously constructed node set
734    ///
735    /// Use previously constructed node set, and specify the node
736    /// label map.
737    template <typename Map>
738    DigraphReader& useNodes(const Map& map) {
739      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
740      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
741      _use_nodes = true;
742      _writer_bits::DefaultConverter<typename Map::Value> converter;
743      for (NodeIt n(_digraph); n != INVALID; ++n) {
744        _node_index.insert(std::make_pair(converter(map[n]), n));
745      }
746      return *this;
747    }
748
749    /// \brief Use previously constructed node set
750    ///
751    /// Use previously constructed node set, and specify the node
752    /// label map and a functor which converts the label map values to
753    /// \c std::string.
754    template <typename Map, typename Converter>
755    DigraphReader& useNodes(const Map& map,
756                            const Converter& converter = Converter()) {
757      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
758      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
759      _use_nodes = true;
760      for (NodeIt n(_digraph); n != INVALID; ++n) {
761        _node_index.insert(std::make_pair(converter(map[n]), n));
762      }
763      return *this;
764    }
765
766    /// \brief Use previously constructed arc set
767    ///
768    /// Use previously constructed arc set, and specify the arc
769    /// label map.
770    template <typename Map>
771    DigraphReader& useArcs(const Map& map) {
772      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
773      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
774      _use_arcs = true;
775      _writer_bits::DefaultConverter<typename Map::Value> converter;
776      for (ArcIt a(_digraph); a != INVALID; ++a) {
777        _arc_index.insert(std::make_pair(converter(map[a]), a));
778      }
779      return *this;
780    }
781
782    /// \brief Use previously constructed arc set
783    ///
784    /// Use previously constructed arc set, and specify the arc
785    /// label map and a functor which converts the label map values to
786    /// \c std::string.
787    template <typename Map, typename Converter>
788    DigraphReader& useArcs(const Map& map,
789                           const Converter& converter = Converter()) {
790      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
791      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
792      _use_arcs = true;
793      for (ArcIt a(_digraph); a != INVALID; ++a) {
794        _arc_index.insert(std::make_pair(converter(map[a]), a));
795      }
796      return *this;
797    }
798
799    /// \brief Skips the reading of node section
800    ///
801    /// Omit the reading of the node section. This implies that each node
802    /// map reading rule will be abandoned, and the nodes of the graph
803    /// will not be constructed, which usually cause that the arc set
804    /// could not be read due to lack of node name resolving.
805    /// Therefore \c skipArcs() function should also be used, or
806    /// \c useNodes() should be used to specify the label of the nodes.
807    DigraphReader& skipNodes() {
808      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
809      _skip_nodes = true;
810      return *this;
811    }
812
813    /// \brief Skips the reading of arc section
814    ///
815    /// Omit the reading of the arc section. This implies that each arc
816    /// map reading rule will be abandoned, and the arcs of the graph
817    /// will not be constructed.
818    DigraphReader& skipArcs() {
819      LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
820      _skip_arcs = true;
821      return *this;
822    }
823
824    /// @}
825
826  private:
827
828    bool readLine() {
829      std::string str;
830      while(++line_num, std::getline(*_is, str)) {
831        line.clear(); line.str(str);
832        char c;
833        if (line >> std::ws >> c && c != '#') {
834          line.putback(c);
835          return true;
836        }
837      }
838      return false;
839    }
840
841    bool readSuccess() {
842      return static_cast<bool>(*_is);
843    }
844
845    void skipSection() {
846      char c;
847      while (readSuccess() && line >> c && c != '@') {
848        readLine();
849      }
850      if (readSuccess()) {
851        line.putback(c);
852      }
853    }
854
855    void readNodes() {
856
857      std::vector<int> map_index(_node_maps.size());
858      int map_num, label_index;
859
860      char c;
861      if (!readLine() || !(line >> c) || c == '@') {
862        if (readSuccess() && line) line.putback(c);
863        if (!_node_maps.empty())
864          throw FormatError("Cannot find map names");
865        return;
866      }
867      line.putback(c);
868
869      {
870        std::map<std::string, int> maps;
871
872        std::string map;
873        int index = 0;
874        while (_reader_bits::readToken(line, map)) {
875          if (maps.find(map) != maps.end()) {
876            std::ostringstream msg;
877            msg << "Multiple occurence of node map: " << map;
878            throw FormatError(msg.str());
879          }
880          maps.insert(std::make_pair(map, index));
881          ++index;
882        }
883
884        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
885          std::map<std::string, int>::iterator jt =
886            maps.find(_node_maps[i].first);
887          if (jt == maps.end()) {
888            std::ostringstream msg;
889            msg << "Map not found: " << _node_maps[i].first;
890            throw FormatError(msg.str());
891          }
892          map_index[i] = jt->second;
893        }
894
895        {
896          std::map<std::string, int>::iterator jt = maps.find("label");
897          if (jt != maps.end()) {
898            label_index = jt->second;
899          } else {
900            label_index = -1;
901          }
902        }
903        map_num = maps.size();
904      }
905
906      while (readLine() && line >> c && c != '@') {
907        line.putback(c);
908
909        std::vector<std::string> tokens(map_num);
910        for (int i = 0; i < map_num; ++i) {
911          if (!_reader_bits::readToken(line, tokens[i])) {
912            std::ostringstream msg;
913            msg << "Column not found (" << i + 1 << ")";
914            throw FormatError(msg.str());
915          }
916        }
917        if (line >> std::ws >> c)
918          throw FormatError("Extra character at the end of line");
919
920        Node n;
921        if (!_use_nodes) {
922          n = _digraph.addNode();
923          if (label_index != -1)
924            _node_index.insert(std::make_pair(tokens[label_index], n));
925        } else {
926          if (label_index == -1)
927            throw FormatError("Label map not found");
928          typename std::map<std::string, Node>::iterator it =
929            _node_index.find(tokens[label_index]);
930          if (it == _node_index.end()) {
931            std::ostringstream msg;
932            msg << "Node with label not found: " << tokens[label_index];
933            throw FormatError(msg.str());
934          }
935          n = it->second;
936        }
937
938        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
939          _node_maps[i].second->set(n, tokens[map_index[i]]);
940        }
941
942      }
943      if (readSuccess()) {
944        line.putback(c);
945      }
946    }
947
948    void readArcs() {
949
950      std::vector<int> map_index(_arc_maps.size());
951      int map_num, label_index;
952
953      char c;
954      if (!readLine() || !(line >> c) || c == '@') {
955        if (readSuccess() && line) line.putback(c);
956        if (!_arc_maps.empty())
957          throw FormatError("Cannot find map names");
958        return;
959      }
960      line.putback(c);
961
962      {
963        std::map<std::string, int> maps;
964
965        std::string map;
966        int index = 0;
967        while (_reader_bits::readToken(line, map)) {
968          if (maps.find(map) != maps.end()) {
969            std::ostringstream msg;
970            msg << "Multiple occurence of arc map: " << map;
971            throw FormatError(msg.str());
972          }
973          maps.insert(std::make_pair(map, index));
974          ++index;
975        }
976
977        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
978          std::map<std::string, int>::iterator jt =
979            maps.find(_arc_maps[i].first);
980          if (jt == maps.end()) {
981            std::ostringstream msg;
982            msg << "Map not found: " << _arc_maps[i].first;
983            throw FormatError(msg.str());
984          }
985          map_index[i] = jt->second;
986        }
987
988        {
989          std::map<std::string, int>::iterator jt = maps.find("label");
990          if (jt != maps.end()) {
991            label_index = jt->second;
992          } else {
993            label_index = -1;
994          }
995        }
996        map_num = maps.size();
997      }
998
999      while (readLine() && line >> c && c != '@') {
1000        line.putback(c);
1001
1002        std::string source_token;
1003        std::string target_token;
1004
1005        if (!_reader_bits::readToken(line, source_token))
1006          throw FormatError("Source not found");
1007
1008        if (!_reader_bits::readToken(line, target_token))
1009          throw FormatError("Target not found");
1010
1011        std::vector<std::string> tokens(map_num);
1012        for (int i = 0; i < map_num; ++i) {
1013          if (!_reader_bits::readToken(line, tokens[i])) {
1014            std::ostringstream msg;
1015            msg << "Column not found (" << i + 1 << ")";
1016            throw FormatError(msg.str());
1017          }
1018        }
1019        if (line >> std::ws >> c)
1020          throw FormatError("Extra character at the end of line");
1021
1022        Arc a;
1023        if (!_use_arcs) {
1024
1025          typename NodeIndex::iterator it;
1026
1027          it = _node_index.find(source_token);
1028          if (it == _node_index.end()) {
1029            std::ostringstream msg;
1030            msg << "Item not found: " << source_token;
1031            throw FormatError(msg.str());
1032          }
1033          Node source = it->second;
1034
1035          it = _node_index.find(target_token);
1036          if (it == _node_index.end()) {
1037            std::ostringstream msg;
1038            msg << "Item not found: " << target_token;
1039            throw FormatError(msg.str());
1040          }
1041          Node target = it->second;
1042
1043          a = _digraph.addArc(source, target);
1044          if (label_index != -1)
1045            _arc_index.insert(std::make_pair(tokens[label_index], a));
1046        } else {
1047          if (label_index == -1)
1048            throw FormatError("Label map not found");
1049          typename std::map<std::string, Arc>::iterator it =
1050            _arc_index.find(tokens[label_index]);
1051          if (it == _arc_index.end()) {
1052            std::ostringstream msg;
1053            msg << "Arc with label not found: " << tokens[label_index];
1054            throw FormatError(msg.str());
1055          }
1056          a = it->second;
1057        }
1058
1059        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
1060          _arc_maps[i].second->set(a, tokens[map_index[i]]);
1061        }
1062
1063      }
1064      if (readSuccess()) {
1065        line.putback(c);
1066      }
1067    }
1068
1069    void readAttributes() {
1070
1071      std::set<std::string> read_attr;
1072
1073      char c;
1074      while (readLine() && line >> c && c != '@') {
1075        line.putback(c);
1076
1077        std::string attr, token;
1078        if (!_reader_bits::readToken(line, attr))
1079          throw FormatError("Attribute name not found");
1080        if (!_reader_bits::readToken(line, token))
1081          throw FormatError("Attribute value not found");
1082        if (line >> c)
1083          throw FormatError("Extra character at the end of line");
1084
1085        {
1086          std::set<std::string>::iterator it = read_attr.find(attr);
1087          if (it != read_attr.end()) {
1088            std::ostringstream msg;
1089            msg << "Multiple occurence of attribute: " << attr;
1090            throw FormatError(msg.str());
1091          }
1092          read_attr.insert(attr);
1093        }
1094
1095        {
1096          typename Attributes::iterator it = _attributes.lower_bound(attr);
1097          while (it != _attributes.end() && it->first == attr) {
1098            it->second->set(token);
1099            ++it;
1100          }
1101        }
1102
1103      }
1104      if (readSuccess()) {
1105        line.putback(c);
1106      }
1107      for (typename Attributes::iterator it = _attributes.begin();
1108           it != _attributes.end(); ++it) {
1109        if (read_attr.find(it->first) == read_attr.end()) {
1110          std::ostringstream msg;
1111          msg << "Attribute not found: " << it->first;
1112          throw FormatError(msg.str());
1113        }
1114      }
1115    }
1116
1117  public:
1118
1119    /// \name Execution of the reader
1120    /// @{
1121
1122    /// \brief Start the batch processing
1123    ///
1124    /// This function starts the batch processing
1125    void run() {
1126      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1127
1128      bool nodes_done = _skip_nodes;
1129      bool arcs_done = _skip_arcs;
1130      bool attributes_done = false;
1131
1132      line_num = 0;
1133      readLine();
1134      skipSection();
1135
1136      while (readSuccess()) {
1137        try {
1138          char c;
1139          std::string section, caption;
1140          line >> c;
1141          _reader_bits::readToken(line, section);
1142          _reader_bits::readToken(line, caption);
1143
1144          if (line >> c)
1145            throw FormatError("Extra character at the end of line");
1146
1147          if (section == "nodes" && !nodes_done) {
1148            if (_nodes_caption.empty() || _nodes_caption == caption) {
1149              readNodes();
1150              nodes_done = true;
1151            }
1152          } else if ((section == "arcs" || section == "edges") &&
1153                     !arcs_done) {
1154            if (_arcs_caption.empty() || _arcs_caption == caption) {
1155              readArcs();
1156              arcs_done = true;
1157            }
1158          } else if (section == "attributes" && !attributes_done) {
1159            if (_attributes_caption.empty() || _attributes_caption == caption) {
1160              readAttributes();
1161              attributes_done = true;
1162            }
1163          } else {
1164            readLine();
1165            skipSection();
1166          }
1167        } catch (FormatError& error) {
1168          error.line(line_num);
1169          error.file(_filename);
1170          throw;
1171        }
1172      }
1173
1174      if (!nodes_done) {
1175        throw FormatError("Section @nodes not found");
1176      }
1177
1178      if (!arcs_done) {
1179        throw FormatError("Section @arcs not found");
1180      }
1181
1182      if (!attributes_done && !_attributes.empty()) {
1183        throw FormatError("Section @attributes not found");
1184      }
1185
1186    }
1187
1188    /// @}
1189
1190  };
1191
1192  /// \brief Return a \ref DigraphReader class
1193  ///
1194  /// This function just returns a \ref DigraphReader class.
1195  /// \relates DigraphReader
1196  template <typename Digraph>
1197  DigraphReader<Digraph> digraphReader(Digraph& digraph, std::istream& is) {
1198    DigraphReader<Digraph> tmp(digraph, is);
1199    return tmp;
1200  }
1201
1202  /// \brief Return a \ref DigraphReader class
1203  ///
1204  /// This function just returns a \ref DigraphReader class.
1205  /// \relates DigraphReader
1206  template <typename Digraph>
1207  DigraphReader<Digraph> digraphReader(Digraph& digraph,
1208                                       const std::string& fn) {
1209    DigraphReader<Digraph> tmp(digraph, fn);
1210    return tmp;
1211  }
1212
1213  /// \brief Return a \ref DigraphReader class
1214  ///
1215  /// This function just returns a \ref DigraphReader class.
1216  /// \relates DigraphReader
1217  template <typename Digraph>
1218  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char* fn) {
1219    DigraphReader<Digraph> tmp(digraph, fn);
1220    return tmp;
1221  }
1222
1223  template <typename Graph>
1224  class GraphReader;
1225 
1226  template <typename Graph>
1227  GraphReader<Graph> graphReader(Graph& graph,
1228                                 std::istream& is = std::cin);
1229  template <typename Graph>
1230  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn);
1231  template <typename Graph>
1232  GraphReader<Graph> graphReader(Graph& graph, const char *fn);
1233
1234  /// \ingroup lemon_io
1235  ///
1236  /// \brief \ref lgf-format "LGF" reader for undirected graphs
1237  ///
1238  /// This utility reads an \ref lgf-format "LGF" file.
1239  ///
1240  /// It can be used almost the same way as \c DigraphReader.
1241  /// The only difference is that this class can handle edges and
1242  /// edge maps as well as arcs and arc maps.
1243  ///
1244  /// The columns in the \c \@edges (or \c \@arcs) section are the
1245  /// edge maps. However, if there are two maps with the same name
1246  /// prefixed with \c '+' and \c '-', then these can be read into an
1247  /// arc map.  Similarly, an attribute can be read into an arc, if
1248  /// it's value is an edge label prefixed with \c '+' or \c '-'.
1249  template <typename _Graph>
1250  class GraphReader {
1251  public:
1252
1253    typedef _Graph Graph;
1254    TEMPLATE_GRAPH_TYPEDEFS(Graph);
1255
1256  private:
1257
1258    std::istream* _is;
1259    bool local_is;
1260    std::string _filename;
1261
1262    Graph& _graph;
1263
1264    std::string _nodes_caption;
1265    std::string _edges_caption;
1266    std::string _attributes_caption;
1267
1268    typedef std::map<std::string, Node> NodeIndex;
1269    NodeIndex _node_index;
1270    typedef std::map<std::string, Edge> EdgeIndex;
1271    EdgeIndex _edge_index;
1272
1273    typedef std::vector<std::pair<std::string,
1274      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
1275    NodeMaps _node_maps;
1276
1277    typedef std::vector<std::pair<std::string,
1278      _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
1279    EdgeMaps _edge_maps;
1280
1281    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
1282      Attributes;
1283    Attributes _attributes;
1284
1285    bool _use_nodes;
1286    bool _use_edges;
1287
1288    bool _skip_nodes;
1289    bool _skip_edges;
1290
1291    int line_num;
1292    std::istringstream line;
1293
1294  public:
1295
1296    /// \brief Constructor
1297    ///
1298    /// Construct an undirected graph reader, which reads from the given
1299    /// input stream.
1300    GraphReader(Graph& graph, std::istream& is = std::cin)
1301      : _is(&is), local_is(false), _graph(graph),
1302        _use_nodes(false), _use_edges(false),
1303        _skip_nodes(false), _skip_edges(false) {}
1304
1305    /// \brief Constructor
1306    ///
1307    /// Construct an undirected graph reader, which reads from the given
1308    /// file.
1309    GraphReader(Graph& graph, const std::string& fn)
1310      : _is(new std::ifstream(fn.c_str())), local_is(true),
1311        _filename(fn), _graph(graph),
1312        _use_nodes(false), _use_edges(false),
1313        _skip_nodes(false), _skip_edges(false) {
1314      if (!(*_is)) {
1315        delete _is;
1316        throw IoError("Cannot open file", fn);
1317      }
1318    }
1319
1320    /// \brief Constructor
1321    ///
1322    /// Construct an undirected graph reader, which reads from the given
1323    /// file.
1324    GraphReader(Graph& graph, const char* fn)
1325      : _is(new std::ifstream(fn)), local_is(true),
1326        _filename(fn), _graph(graph),
1327        _use_nodes(false), _use_edges(false),
1328        _skip_nodes(false), _skip_edges(false) {
1329      if (!(*_is)) {
1330        delete _is;
1331        throw IoError("Cannot open file", fn);
1332      }
1333    }
1334
1335    /// \brief Destructor
1336    ~GraphReader() {
1337      for (typename NodeMaps::iterator it = _node_maps.begin();
1338           it != _node_maps.end(); ++it) {
1339        delete it->second;
1340      }
1341
1342      for (typename EdgeMaps::iterator it = _edge_maps.begin();
1343           it != _edge_maps.end(); ++it) {
1344        delete it->second;
1345      }
1346
1347      for (typename Attributes::iterator it = _attributes.begin();
1348           it != _attributes.end(); ++it) {
1349        delete it->second;
1350      }
1351
1352      if (local_is) {
1353        delete _is;
1354      }
1355
1356    }
1357
1358  private:
1359    template <typename GR>
1360    friend GraphReader<GR> graphReader(GR& graph, std::istream& is);
1361    template <typename GR>
1362    friend GraphReader<GR> graphReader(GR& graph, const std::string& fn);
1363    template <typename GR>
1364    friend GraphReader<GR> graphReader(GR& graph, const char *fn);
1365
1366    GraphReader(GraphReader& other)
1367      : _is(other._is), local_is(other.local_is), _graph(other._graph),
1368        _use_nodes(other._use_nodes), _use_edges(other._use_edges),
1369        _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
1370
1371      other._is = 0;
1372      other.local_is = false;
1373
1374      _node_index.swap(other._node_index);
1375      _edge_index.swap(other._edge_index);
1376
1377      _node_maps.swap(other._node_maps);
1378      _edge_maps.swap(other._edge_maps);
1379      _attributes.swap(other._attributes);
1380
1381      _nodes_caption = other._nodes_caption;
1382      _edges_caption = other._edges_caption;
1383      _attributes_caption = other._attributes_caption;
1384
1385    }
1386
1387    GraphReader& operator=(const GraphReader&);
1388
1389  public:
1390
1391    /// \name Reading rules
1392    /// @{
1393
1394    /// \brief Node map reading rule
1395    ///
1396    /// Add a node map reading rule to the reader.
1397    template <typename Map>
1398    GraphReader& nodeMap(const std::string& caption, Map& map) {
1399      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1400      _reader_bits::MapStorageBase<Node>* storage =
1401        new _reader_bits::MapStorage<Node, Map>(map);
1402      _node_maps.push_back(std::make_pair(caption, storage));
1403      return *this;
1404    }
1405
1406    /// \brief Node map reading rule
1407    ///
1408    /// Add a node map reading rule with specialized converter to the
1409    /// reader.
1410    template <typename Map, typename Converter>
1411    GraphReader& nodeMap(const std::string& caption, Map& map,
1412                           const Converter& converter = Converter()) {
1413      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1414      _reader_bits::MapStorageBase<Node>* storage =
1415        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
1416      _node_maps.push_back(std::make_pair(caption, storage));
1417      return *this;
1418    }
1419
1420    /// \brief Edge map reading rule
1421    ///
1422    /// Add an edge map reading rule to the reader.
1423    template <typename Map>
1424    GraphReader& edgeMap(const std::string& caption, Map& map) {
1425      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1426      _reader_bits::MapStorageBase<Edge>* storage =
1427        new _reader_bits::MapStorage<Edge, Map>(map);
1428      _edge_maps.push_back(std::make_pair(caption, storage));
1429      return *this;
1430    }
1431
1432    /// \brief Edge map reading rule
1433    ///
1434    /// Add an edge map reading rule with specialized converter to the
1435    /// reader.
1436    template <typename Map, typename Converter>
1437    GraphReader& edgeMap(const std::string& caption, Map& map,
1438                          const Converter& converter = Converter()) {
1439      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1440      _reader_bits::MapStorageBase<Edge>* storage =
1441        new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
1442      _edge_maps.push_back(std::make_pair(caption, storage));
1443      return *this;
1444    }
1445
1446    /// \brief Arc map reading rule
1447    ///
1448    /// Add an arc map reading rule to the reader.
1449    template <typename Map>
1450    GraphReader& arcMap(const std::string& caption, Map& map) {
1451      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1452      _reader_bits::MapStorageBase<Edge>* forward_storage =
1453        new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
1454      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1455      _reader_bits::MapStorageBase<Edge>* backward_storage =
1456        new _reader_bits::GraphArcMapStorage<Graph, false, Map>(_graph, map);
1457      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1458      return *this;
1459    }
1460
1461    /// \brief Arc map reading rule
1462    ///
1463    /// Add an arc map reading rule with specialized converter to the
1464    /// reader.
1465    template <typename Map, typename Converter>
1466    GraphReader& arcMap(const std::string& caption, Map& map,
1467                          const Converter& converter = Converter()) {
1468      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1469      _reader_bits::MapStorageBase<Edge>* forward_storage =
1470        new _reader_bits::GraphArcMapStorage<Graph, true, Map, Converter>
1471        (_graph, map, converter);
1472      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1473      _reader_bits::MapStorageBase<Edge>* backward_storage =
1474        new _reader_bits::GraphArcMapStorage<Graph, false, Map, Converter>
1475        (_graph, map, converter);
1476      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1477      return *this;
1478    }
1479
1480    /// \brief Attribute reading rule
1481    ///
1482    /// Add an attribute reading rule to the reader.
1483    template <typename Value>
1484    GraphReader& attribute(const std::string& caption, Value& value) {
1485      _reader_bits::ValueStorageBase* storage =
1486        new _reader_bits::ValueStorage<Value>(value);
1487      _attributes.insert(std::make_pair(caption, storage));
1488      return *this;
1489    }
1490
1491    /// \brief Attribute reading rule
1492    ///
1493    /// Add an attribute reading rule with specialized converter to the
1494    /// reader.
1495    template <typename Value, typename Converter>
1496    GraphReader& attribute(const std::string& caption, Value& value,
1497                             const Converter& converter = Converter()) {
1498      _reader_bits::ValueStorageBase* storage =
1499        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
1500      _attributes.insert(std::make_pair(caption, storage));
1501      return *this;
1502    }
1503
1504    /// \brief Node reading rule
1505    ///
1506    /// Add a node reading rule to reader.
1507    GraphReader& node(const std::string& caption, Node& node) {
1508      typedef _reader_bits::MapLookUpConverter<Node> Converter;
1509      Converter converter(_node_index);
1510      _reader_bits::ValueStorageBase* storage =
1511        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
1512      _attributes.insert(std::make_pair(caption, storage));
1513      return *this;
1514    }
1515
1516    /// \brief Edge reading rule
1517    ///
1518    /// Add an edge reading rule to reader.
1519    GraphReader& edge(const std::string& caption, Edge& edge) {
1520      typedef _reader_bits::MapLookUpConverter<Edge> Converter;
1521      Converter converter(_edge_index);
1522      _reader_bits::ValueStorageBase* storage =
1523        new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
1524      _attributes.insert(std::make_pair(caption, storage));
1525      return *this;
1526    }
1527
1528    /// \brief Arc reading rule
1529    ///
1530    /// Add an arc reading rule to reader.
1531    GraphReader& arc(const std::string& caption, Arc& arc) {
1532      typedef _reader_bits::GraphArcLookUpConverter<Graph> Converter;
1533      Converter converter(_graph, _edge_index);
1534      _reader_bits::ValueStorageBase* storage =
1535        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
1536      _attributes.insert(std::make_pair(caption, storage));
1537      return *this;
1538    }
1539
1540    /// @}
1541
1542    /// \name Select section by name
1543    /// @{
1544
1545    /// \brief Set \c \@nodes section to be read
1546    ///
1547    /// Set \c \@nodes section to be read.
1548    GraphReader& nodes(const std::string& caption) {
1549      _nodes_caption = caption;
1550      return *this;
1551    }
1552
1553    /// \brief Set \c \@edges section to be read
1554    ///
1555    /// Set \c \@edges section to be read.
1556    GraphReader& edges(const std::string& caption) {
1557      _edges_caption = caption;
1558      return *this;
1559    }
1560
1561    /// \brief Set \c \@attributes section to be read
1562    ///
1563    /// Set \c \@attributes section to be read.
1564    GraphReader& attributes(const std::string& caption) {
1565      _attributes_caption = caption;
1566      return *this;
1567    }
1568
1569    /// @}
1570
1571    /// \name Using previously constructed node or edge set
1572    /// @{
1573
1574    /// \brief Use previously constructed node set
1575    ///
1576    /// Use previously constructed node set, and specify the node
1577    /// label map.
1578    template <typename Map>
1579    GraphReader& useNodes(const Map& map) {
1580      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1581      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1582      _use_nodes = true;
1583      _writer_bits::DefaultConverter<typename Map::Value> converter;
1584      for (NodeIt n(_graph); n != INVALID; ++n) {
1585        _node_index.insert(std::make_pair(converter(map[n]), n));
1586      }
1587      return *this;
1588    }
1589
1590    /// \brief Use previously constructed node set
1591    ///
1592    /// Use previously constructed node set, and specify the node
1593    /// label map and a functor which converts the label map values to
1594    /// \c std::string.
1595    template <typename Map, typename Converter>
1596    GraphReader& useNodes(const Map& map,
1597                            const Converter& converter = Converter()) {
1598      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1599      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1600      _use_nodes = true;
1601      for (NodeIt n(_graph); n != INVALID; ++n) {
1602        _node_index.insert(std::make_pair(converter(map[n]), n));
1603      }
1604      return *this;
1605    }
1606
1607    /// \brief Use previously constructed edge set
1608    ///
1609    /// Use previously constructed edge set, and specify the edge
1610    /// label map.
1611    template <typename Map>
1612    GraphReader& useEdges(const Map& map) {
1613      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1614      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1615      _use_edges = true;
1616      _writer_bits::DefaultConverter<typename Map::Value> converter;
1617      for (EdgeIt a(_graph); a != INVALID; ++a) {
1618        _edge_index.insert(std::make_pair(converter(map[a]), a));
1619      }
1620      return *this;
1621    }
1622
1623    /// \brief Use previously constructed edge set
1624    ///
1625    /// Use previously constructed edge set, and specify the edge
1626    /// label map and a functor which converts the label map values to
1627    /// \c std::string.
1628    template <typename Map, typename Converter>
1629    GraphReader& useEdges(const Map& map,
1630                            const Converter& converter = Converter()) {
1631      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1632      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1633      _use_edges = true;
1634      for (EdgeIt a(_graph); a != INVALID; ++a) {
1635        _edge_index.insert(std::make_pair(converter(map[a]), a));
1636      }
1637      return *this;
1638    }
1639
1640    /// \brief Skip the reading of node section
1641    ///
1642    /// Omit the reading of the node section. This implies that each node
1643    /// map reading rule will be abandoned, and the nodes of the graph
1644    /// will not be constructed, which usually cause that the edge set
1645    /// could not be read due to lack of node name
1646    /// could not be read due to lack of node name resolving.
1647    /// Therefore \c skipEdges() function should also be used, or
1648    /// \c useNodes() should be used to specify the label of the nodes.
1649    GraphReader& skipNodes() {
1650      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
1651      _skip_nodes = true;
1652      return *this;
1653    }
1654
1655    /// \brief Skip the reading of edge section
1656    ///
1657    /// Omit the reading of the edge section. This implies that each edge
1658    /// map reading rule will be abandoned, and the edges of the graph
1659    /// will not be constructed.
1660    GraphReader& skipEdges() {
1661      LEMON_ASSERT(!_skip_edges, "Skip edges already set");
1662      _skip_edges = true;
1663      return *this;
1664    }
1665
1666    /// @}
1667
1668  private:
1669
1670    bool readLine() {
1671      std::string str;
1672      while(++line_num, std::getline(*_is, str)) {
1673        line.clear(); line.str(str);
1674        char c;
1675        if (line >> std::ws >> c && c != '#') {
1676          line.putback(c);
1677          return true;
1678        }
1679      }
1680      return false;
1681    }
1682
1683    bool readSuccess() {
1684      return static_cast<bool>(*_is);
1685    }
1686
1687    void skipSection() {
1688      char c;
1689      while (readSuccess() && line >> c && c != '@') {
1690        readLine();
1691      }
1692      if (readSuccess()) {
1693        line.putback(c);
1694      }
1695    }
1696
1697    void readNodes() {
1698
1699      std::vector<int> map_index(_node_maps.size());
1700      int map_num, label_index;
1701
1702      char c;
1703      if (!readLine() || !(line >> c) || c == '@') {
1704        if (readSuccess() && line) line.putback(c);
1705        if (!_node_maps.empty())
1706          throw FormatError("Cannot find map names");
1707        return;
1708      }
1709      line.putback(c);
1710
1711      {
1712        std::map<std::string, int> maps;
1713
1714        std::string map;
1715        int index = 0;
1716        while (_reader_bits::readToken(line, map)) {
1717          if (maps.find(map) != maps.end()) {
1718            std::ostringstream msg;
1719            msg << "Multiple occurence of node map: " << map;
1720            throw FormatError(msg.str());
1721          }
1722          maps.insert(std::make_pair(map, index));
1723          ++index;
1724        }
1725
1726        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1727          std::map<std::string, int>::iterator jt =
1728            maps.find(_node_maps[i].first);
1729          if (jt == maps.end()) {
1730            std::ostringstream msg;
1731            msg << "Map not found: " << _node_maps[i].first;
1732            throw FormatError(msg.str());
1733          }
1734          map_index[i] = jt->second;
1735        }
1736
1737        {
1738          std::map<std::string, int>::iterator jt = maps.find("label");
1739          if (jt != maps.end()) {
1740            label_index = jt->second;
1741          } else {
1742            label_index = -1;
1743          }
1744        }
1745        map_num = maps.size();
1746      }
1747
1748      while (readLine() && line >> c && c != '@') {
1749        line.putback(c);
1750
1751        std::vector<std::string> tokens(map_num);
1752        for (int i = 0; i < map_num; ++i) {
1753          if (!_reader_bits::readToken(line, tokens[i])) {
1754            std::ostringstream msg;
1755            msg << "Column not found (" << i + 1 << ")";
1756            throw FormatError(msg.str());
1757          }
1758        }
1759        if (line >> std::ws >> c)
1760          throw FormatError("Extra character at the end of line");
1761
1762        Node n;
1763        if (!_use_nodes) {
1764          n = _graph.addNode();
1765          if (label_index != -1)
1766            _node_index.insert(std::make_pair(tokens[label_index], n));
1767        } else {
1768          if (label_index == -1)
1769            throw FormatError("Label map not found");
1770          typename std::map<std::string, Node>::iterator it =
1771            _node_index.find(tokens[label_index]);
1772          if (it == _node_index.end()) {
1773            std::ostringstream msg;
1774            msg << "Node with label not found: " << tokens[label_index];
1775            throw FormatError(msg.str());
1776          }
1777          n = it->second;
1778        }
1779
1780        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1781          _node_maps[i].second->set(n, tokens[map_index[i]]);
1782        }
1783
1784      }
1785      if (readSuccess()) {
1786        line.putback(c);
1787      }
1788    }
1789
1790    void readEdges() {
1791
1792      std::vector<int> map_index(_edge_maps.size());
1793      int map_num, label_index;
1794
1795      char c;
1796      if (!readLine() || !(line >> c) || c == '@') {
1797        if (readSuccess() && line) line.putback(c);
1798        if (!_edge_maps.empty())
1799          throw FormatError("Cannot find map names");
1800        return;
1801      }
1802      line.putback(c);
1803
1804      {
1805        std::map<std::string, int> maps;
1806
1807        std::string map;
1808        int index = 0;
1809        while (_reader_bits::readToken(line, map)) {
1810          if (maps.find(map) != maps.end()) {
1811            std::ostringstream msg;
1812            msg << "Multiple occurence of edge map: " << map;
1813            throw FormatError(msg.str());
1814          }
1815          maps.insert(std::make_pair(map, index));
1816          ++index;
1817        }
1818
1819        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1820          std::map<std::string, int>::iterator jt =
1821            maps.find(_edge_maps[i].first);
1822          if (jt == maps.end()) {
1823            std::ostringstream msg;
1824            msg << "Map not found: " << _edge_maps[i].first;
1825            throw FormatError(msg.str());
1826          }
1827          map_index[i] = jt->second;
1828        }
1829
1830        {
1831          std::map<std::string, int>::iterator jt = maps.find("label");
1832          if (jt != maps.end()) {
1833            label_index = jt->second;
1834          } else {
1835            label_index = -1;
1836          }
1837        }
1838        map_num = maps.size();
1839      }
1840
1841      while (readLine() && line >> c && c != '@') {
1842        line.putback(c);
1843
1844        std::string source_token;
1845        std::string target_token;
1846
1847        if (!_reader_bits::readToken(line, source_token))
1848          throw FormatError("Node u not found");
1849
1850        if (!_reader_bits::readToken(line, target_token))
1851          throw FormatError("Node v not found");
1852
1853        std::vector<std::string> tokens(map_num);
1854        for (int i = 0; i < map_num; ++i) {
1855          if (!_reader_bits::readToken(line, tokens[i])) {
1856            std::ostringstream msg;
1857            msg << "Column not found (" << i + 1 << ")";
1858            throw FormatError(msg.str());
1859          }
1860        }
1861        if (line >> std::ws >> c)
1862          throw FormatError("Extra character at the end of line");
1863
1864        Edge e;
1865        if (!_use_edges) {
1866
1867          typename NodeIndex::iterator it;
1868
1869          it = _node_index.find(source_token);
1870          if (it == _node_index.end()) {
1871            std::ostringstream msg;
1872            msg << "Item not found: " << source_token;
1873            throw FormatError(msg.str());
1874          }
1875          Node source = it->second;
1876
1877          it = _node_index.find(target_token);
1878          if (it == _node_index.end()) {
1879            std::ostringstream msg;
1880            msg << "Item not found: " << target_token;
1881            throw FormatError(msg.str());
1882          }
1883          Node target = it->second;
1884
1885          e = _graph.addEdge(source, target);
1886          if (label_index != -1)
1887            _edge_index.insert(std::make_pair(tokens[label_index], e));
1888        } else {
1889          if (label_index == -1)
1890            throw FormatError("Label map not found");
1891          typename std::map<std::string, Edge>::iterator it =
1892            _edge_index.find(tokens[label_index]);
1893          if (it == _edge_index.end()) {
1894            std::ostringstream msg;
1895            msg << "Edge with label not found: " << tokens[label_index];
1896            throw FormatError(msg.str());
1897          }
1898          e = it->second;
1899        }
1900
1901        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1902          _edge_maps[i].second->set(e, tokens[map_index[i]]);
1903        }
1904
1905      }
1906      if (readSuccess()) {
1907        line.putback(c);
1908      }
1909    }
1910
1911    void readAttributes() {
1912
1913      std::set<std::string> read_attr;
1914
1915      char c;
1916      while (readLine() && line >> c && c != '@') {
1917        line.putback(c);
1918
1919        std::string attr, token;
1920        if (!_reader_bits::readToken(line, attr))
1921          throw FormatError("Attribute name not found");
1922        if (!_reader_bits::readToken(line, token))
1923          throw FormatError("Attribute value not found");
1924        if (line >> c)
1925          throw FormatError("Extra character at the end of line");
1926
1927        {
1928          std::set<std::string>::iterator it = read_attr.find(attr);
1929          if (it != read_attr.end()) {
1930            std::ostringstream msg;
1931            msg << "Multiple occurence of attribute: " << attr;
1932            throw FormatError(msg.str());
1933          }
1934          read_attr.insert(attr);
1935        }
1936
1937        {
1938          typename Attributes::iterator it = _attributes.lower_bound(attr);
1939          while (it != _attributes.end() && it->first == attr) {
1940            it->second->set(token);
1941            ++it;
1942          }
1943        }
1944
1945      }
1946      if (readSuccess()) {
1947        line.putback(c);
1948      }
1949      for (typename Attributes::iterator it = _attributes.begin();
1950           it != _attributes.end(); ++it) {
1951        if (read_attr.find(it->first) == read_attr.end()) {
1952          std::ostringstream msg;
1953          msg << "Attribute not found: " << it->first;
1954          throw FormatError(msg.str());
1955        }
1956      }
1957    }
1958
1959  public:
1960
1961    /// \name Execution of the reader
1962    /// @{
1963
1964    /// \brief Start the batch processing
1965    ///
1966    /// This function starts the batch processing
1967    void run() {
1968
1969      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1970
1971      bool nodes_done = _skip_nodes;
1972      bool edges_done = _skip_edges;
1973      bool attributes_done = false;
1974
1975      line_num = 0;
1976      readLine();
1977      skipSection();
1978
1979      while (readSuccess()) {
1980        try {
1981          char c;
1982          std::string section, caption;
1983          line >> c;
1984          _reader_bits::readToken(line, section);
1985          _reader_bits::readToken(line, caption);
1986
1987          if (line >> c)
1988            throw FormatError("Extra character at the end of line");
1989
1990          if (section == "nodes" && !nodes_done) {
1991            if (_nodes_caption.empty() || _nodes_caption == caption) {
1992              readNodes();
1993              nodes_done = true;
1994            }
1995          } else if ((section == "edges" || section == "arcs") &&
1996                     !edges_done) {
1997            if (_edges_caption.empty() || _edges_caption == caption) {
1998              readEdges();
1999              edges_done = true;
2000            }
2001          } else if (section == "attributes" && !attributes_done) {
2002            if (_attributes_caption.empty() || _attributes_caption == caption) {
2003              readAttributes();
2004              attributes_done = true;
2005            }
2006          } else {
2007            readLine();
2008            skipSection();
2009          }
2010        } catch (FormatError& error) {
2011          error.line(line_num);
2012          error.file(_filename);
2013          throw;
2014        }
2015      }
2016
2017      if (!nodes_done) {
2018        throw FormatError("Section @nodes not found");
2019      }
2020
2021      if (!edges_done) {
2022        throw FormatError("Section @edges not found");
2023      }
2024
2025      if (!attributes_done && !_attributes.empty()) {
2026        throw FormatError("Section @attributes not found");
2027      }
2028
2029    }
2030
2031    /// @}
2032
2033  };
2034
2035  /// \brief Return a \ref GraphReader class
2036  ///
2037  /// This function just returns a \ref GraphReader class.
2038  /// \relates GraphReader
2039  template <typename Graph>
2040  GraphReader<Graph> graphReader(Graph& graph, std::istream& is) {
2041    GraphReader<Graph> tmp(graph, is);
2042    return tmp;
2043  }
2044
2045  /// \brief Return a \ref GraphReader class
2046  ///
2047  /// This function just returns a \ref GraphReader class.
2048  /// \relates GraphReader
2049  template <typename Graph>
2050  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {
2051    GraphReader<Graph> tmp(graph, fn);
2052    return tmp;
2053  }
2054
2055  /// \brief Return a \ref GraphReader class
2056  ///
2057  /// This function just returns a \ref GraphReader class.
2058  /// \relates GraphReader
2059  template <typename Graph>
2060  GraphReader<Graph> graphReader(Graph& graph, const char* fn) {
2061    GraphReader<Graph> tmp(graph, fn);
2062    return tmp;
2063  }
2064
2065  class SectionReader;
2066
2067  SectionReader sectionReader(std::istream& is);
2068  SectionReader sectionReader(const std::string& fn);
2069  SectionReader sectionReader(const char* fn);
2070
2071  /// \ingroup lemon_io
2072  ///
2073  /// \brief Section reader class
2074  ///
2075  /// In the \ref lgf-format "LGF" file extra sections can be placed,
2076  /// which contain any data in arbitrary format. Such sections can be
2077  /// read with this class. A reading rule can be added to the class
2078  /// with two different functions. With the \c sectionLines() function a
2079  /// functor can process the section line-by-line, while with the \c
2080  /// sectionStream() member the section can be read from an input
2081  /// stream.
2082  class SectionReader {
2083  private:
2084
2085    std::istream* _is;
2086    bool local_is;
2087    std::string _filename;
2088
2089    typedef std::map<std::string, _reader_bits::Section*> Sections;
2090    Sections _sections;
2091
2092    int line_num;
2093    std::istringstream line;
2094
2095  public:
2096
2097    /// \brief Constructor
2098    ///
2099    /// Construct a section reader, which reads from the given input
2100    /// stream.
2101    SectionReader(std::istream& is)
2102      : _is(&is), local_is(false) {}
2103
2104    /// \brief Constructor
2105    ///
2106    /// Construct a section reader, which reads from the given file.
2107    SectionReader(const std::string& fn)
2108      : _is(new std::ifstream(fn.c_str())), local_is(true),
2109        _filename(fn) {
2110      if (!(*_is)) {
2111        delete _is;
2112        throw IoError("Cannot open file", fn);
2113      }
2114    }
2115
2116    /// \brief Constructor
2117    ///
2118    /// Construct a section reader, which reads from the given file.
2119    SectionReader(const char* fn)
2120      : _is(new std::ifstream(fn)), local_is(true),
2121        _filename(fn) {
2122      if (!(*_is)) {
2123        delete _is;
2124        throw IoError("Cannot open file", fn);
2125      }
2126    }
2127
2128    /// \brief Destructor
2129    ~SectionReader() {
2130      for (Sections::iterator it = _sections.begin();
2131           it != _sections.end(); ++it) {
2132        delete it->second;
2133      }
2134
2135      if (local_is) {
2136        delete _is;
2137      }
2138
2139    }
2140
2141  private:
2142
2143    friend SectionReader sectionReader(std::istream& is);
2144    friend SectionReader sectionReader(const std::string& fn);
2145    friend SectionReader sectionReader(const char* fn);
2146
2147    SectionReader(SectionReader& other)
2148      : _is(other._is), local_is(other.local_is) {
2149
2150      other._is = 0;
2151      other.local_is = false;
2152
2153      _sections.swap(other._sections);
2154    }
2155
2156    SectionReader& operator=(const SectionReader&);
2157
2158  public:
2159
2160    /// \name Section readers
2161    /// @{
2162
2163    /// \brief Add a section processor with line oriented reading
2164    ///
2165    /// The first parameter is the type descriptor of the section, the
2166    /// second is a functor, which takes just one \c std::string
2167    /// parameter. At the reading process, each line of the section
2168    /// will be given to the functor object. However, the empty lines
2169    /// and the comment lines are filtered out, and the leading
2170    /// whitespaces are trimmed from each processed string.
2171    ///
2172    /// For example let's see a section, which contain several
2173    /// integers, which should be inserted into a vector.
2174    ///\code
2175    ///  @numbers
2176    ///  12 45 23
2177    ///  4
2178    ///  23 6
2179    ///\endcode
2180    ///
2181    /// The functor is implemented as a struct:
2182    ///\code
2183    ///  struct NumberSection {
2184    ///    std::vector<int>& _data;
2185    ///    NumberSection(std::vector<int>& data) : _data(data) {}
2186    ///    void operator()(const std::string& line) {
2187    ///      std::istringstream ls(line);
2188    ///      int value;
2189    ///      while (ls >> value) _data.push_back(value);
2190    ///    }
2191    ///  };
2192    ///
2193    ///  // ...
2194    ///
2195    ///  reader.sectionLines("numbers", NumberSection(vec));
2196    ///\endcode
2197    template <typename Functor>
2198    SectionReader& sectionLines(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::LineSection<Functor>(functor)));
2204      return *this;
2205    }
2206
2207
2208    /// \brief Add a section processor with stream oriented reading
2209    ///
2210    /// The first parameter is the type of the section, the second is
2211    /// a functor, which takes an \c std::istream& and an \c int&
2212    /// parameter, the latter regard to the line number of stream. The
2213    /// functor can read the input while the section go on, and the
2214    /// line number should be modified accordingly.
2215    template <typename Functor>
2216    SectionReader& sectionStream(const std::string& type, Functor functor) {
2217      LEMON_ASSERT(!type.empty(), "Type is empty.");
2218      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2219                   "Multiple reading of section.");
2220      _sections.insert(std::make_pair(type,
2221         new _reader_bits::StreamSection<Functor>(functor)));
2222      return *this;
2223    }
2224
2225    /// @}
2226
2227  private:
2228
2229    bool readLine() {
2230      std::string str;
2231      while(++line_num, std::getline(*_is, str)) {
2232        line.clear(); line.str(str);
2233        char c;
2234        if (line >> std::ws >> c && c != '#') {
2235          line.putback(c);
2236          return true;
2237        }
2238      }
2239      return false;
2240    }
2241
2242    bool readSuccess() {
2243      return static_cast<bool>(*_is);
2244    }
2245
2246    void skipSection() {
2247      char c;
2248      while (readSuccess() && line >> c && c != '@') {
2249        readLine();
2250      }
2251      if (readSuccess()) {
2252        line.putback(c);
2253      }
2254    }
2255
2256  public:
2257
2258
2259    /// \name Execution of the reader
2260    /// @{
2261
2262    /// \brief Start the batch processing
2263    ///
2264    /// This function starts the batch processing.
2265    void run() {
2266
2267      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
2268
2269      std::set<std::string> extra_sections;
2270
2271      line_num = 0;
2272      readLine();
2273      skipSection();
2274
2275      while (readSuccess()) {
2276        try {
2277          char c;
2278          std::string section, caption;
2279          line >> c;
2280          _reader_bits::readToken(line, section);
2281          _reader_bits::readToken(line, caption);
2282
2283          if (line >> c)
2284            throw FormatError("Extra character at the end of line");
2285
2286          if (extra_sections.find(section) != extra_sections.end()) {
2287            std::ostringstream msg;
2288            msg << "Multiple occurence of section: " << section;
2289            throw FormatError(msg.str());
2290          }
2291          Sections::iterator it = _sections.find(section);
2292          if (it != _sections.end()) {
2293            extra_sections.insert(section);
2294            it->second->process(*_is, line_num);
2295          }
2296          readLine();
2297          skipSection();
2298        } catch (FormatError& error) {
2299          error.line(line_num);
2300          error.file(_filename);
2301          throw;
2302        }
2303      }
2304      for (Sections::iterator it = _sections.begin();
2305           it != _sections.end(); ++it) {
2306        if (extra_sections.find(it->first) == extra_sections.end()) {
2307          std::ostringstream os;
2308          os << "Cannot find section: " << it->first;
2309          throw FormatError(os.str());
2310        }
2311      }
2312    }
2313
2314    /// @}
2315
2316  };
2317
2318  /// \brief Return a \ref SectionReader class
2319  ///
2320  /// This function just returns a \ref SectionReader class.
2321  /// \relates SectionReader
2322  inline SectionReader sectionReader(std::istream& is) {
2323    SectionReader tmp(is);
2324    return tmp;
2325  }
2326
2327  /// \brief Return a \ref SectionReader class
2328  ///
2329  /// This function just returns a \ref SectionReader class.
2330  /// \relates SectionReader
2331  inline SectionReader sectionReader(const std::string& fn) {
2332    SectionReader tmp(fn);
2333    return tmp;
2334  }
2335
2336  /// \brief Return a \ref SectionReader class
2337  ///
2338  /// This function just returns a \ref SectionReader class.
2339  /// \relates SectionReader
2340  inline SectionReader sectionReader(const char* fn) {
2341    SectionReader tmp(fn);
2342    return tmp;
2343  }
2344
2345  /// \ingroup lemon_io
2346  ///
2347  /// \brief Reader for the contents of the \ref lgf-format "LGF" file
2348  ///
2349  /// This class can be used to read the sections, the map names and
2350  /// the attributes from a file. Usually, the LEMON programs know
2351  /// that, which type of graph, which maps and which attributes
2352  /// should be read from a file, but in general tools (like glemon)
2353  /// the contents of an LGF file should be guessed somehow. This class
2354  /// reads the graph and stores the appropriate information for
2355  /// reading the graph.
2356  ///
2357  ///\code
2358  /// LgfContents contents("graph.lgf");
2359  /// contents.run();
2360  ///
2361  /// // Does it contain any node section and arc section?
2362  /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
2363  ///   std::cerr << "Failure, cannot find graph." << std::endl;
2364  ///   return -1;
2365  /// }
2366  /// std::cout << "The name of the default node section: "
2367  ///           << contents.nodeSection(0) << std::endl;
2368  /// std::cout << "The number of the arc maps: "
2369  ///           << contents.arcMaps(0).size() << std::endl;
2370  /// std::cout << "The name of second arc map: "
2371  ///           << contents.arcMaps(0)[1] << std::endl;
2372  ///\endcode
2373  class LgfContents {
2374  private:
2375
2376    std::istream* _is;
2377    bool local_is;
2378
2379    std::vector<std::string> _node_sections;
2380    std::vector<std::string> _edge_sections;
2381    std::vector<std::string> _attribute_sections;
2382    std::vector<std::string> _extra_sections;
2383
2384    std::vector<bool> _arc_sections;
2385
2386    std::vector<std::vector<std::string> > _node_maps;
2387    std::vector<std::vector<std::string> > _edge_maps;
2388
2389    std::vector<std::vector<std::string> > _attributes;
2390
2391
2392    int line_num;
2393    std::istringstream line;
2394
2395  public:
2396
2397    /// \brief Constructor
2398    ///
2399    /// Construct an \e LGF contents reader, which reads from the given
2400    /// input stream.
2401    LgfContents(std::istream& is)
2402      : _is(&is), local_is(false) {}
2403
2404    /// \brief Constructor
2405    ///
2406    /// Construct an \e LGF contents reader, which reads from the given
2407    /// file.
2408    LgfContents(const std::string& fn)
2409      : _is(new std::ifstream(fn.c_str())), local_is(true) {
2410      if (!(*_is)) {
2411        delete _is;
2412        throw IoError("Cannot open file", fn);
2413      }
2414    }
2415
2416    /// \brief Constructor
2417    ///
2418    /// Construct an \e LGF contents reader, which reads from the given
2419    /// file.
2420    LgfContents(const char* fn)
2421      : _is(new std::ifstream(fn)), local_is(true) {
2422      if (!(*_is)) {
2423        delete _is;
2424        throw IoError("Cannot open file", fn);
2425      }
2426    }
2427
2428    /// \brief Destructor
2429    ~LgfContents() {
2430      if (local_is) delete _is;
2431    }
2432
2433  private:
2434
2435    LgfContents(const LgfContents&);
2436    LgfContents& operator=(const LgfContents&);
2437
2438  public:
2439
2440
2441    /// \name Node sections
2442    /// @{
2443
2444    /// \brief Gives back the number of node sections in the file.
2445    ///
2446    /// Gives back the number of node sections in the file.
2447    int nodeSectionNum() const {
2448      return _node_sections.size();
2449    }
2450
2451    /// \brief Returns the node section name at the given position.
2452    ///
2453    /// Returns the node section name at the given position.
2454    const std::string& nodeSection(int i) const {
2455      return _node_sections[i];
2456    }
2457
2458    /// \brief Gives back the node maps for the given section.
2459    ///
2460    /// Gives back the node maps for the given section.
2461    const std::vector<std::string>& nodeMapNames(int i) const {
2462      return _node_maps[i];
2463    }
2464
2465    /// @}
2466
2467    /// \name Arc/Edge sections
2468    /// @{
2469
2470    /// \brief Gives back the number of arc/edge sections in the file.
2471    ///
2472    /// Gives back the number of arc/edge sections in the file.
2473    /// \note It is synonym of \c edgeSectionNum().
2474    int arcSectionNum() const {
2475      return _edge_sections.size();
2476    }
2477
2478    /// \brief Returns the arc/edge section name at the given position.
2479    ///
2480    /// Returns the arc/edge section name at the given position.
2481    /// \note It is synonym of \c edgeSection().
2482    const std::string& arcSection(int i) const {
2483      return _edge_sections[i];
2484    }
2485
2486    /// \brief Gives back the arc/edge maps for the given section.
2487    ///
2488    /// Gives back the arc/edge maps for the given section.
2489    /// \note It is synonym of \c edgeMapNames().
2490    const std::vector<std::string>& arcMapNames(int i) const {
2491      return _edge_maps[i];
2492    }
2493
2494    /// @}
2495
2496    /// \name Synonyms
2497    /// @{
2498
2499    /// \brief Gives back the number of arc/edge sections in the file.
2500    ///
2501    /// Gives back the number of arc/edge sections in the file.
2502    /// \note It is synonym of \c arcSectionNum().
2503    int edgeSectionNum() const {
2504      return _edge_sections.size();
2505    }
2506
2507    /// \brief Returns the section name at the given position.
2508    ///
2509    /// Returns the section name at the given position.
2510    /// \note It is synonym of \c arcSection().
2511    const std::string& edgeSection(int i) const {
2512      return _edge_sections[i];
2513    }
2514
2515    /// \brief Gives back the edge maps for the given section.
2516    ///
2517    /// Gives back the edge maps for the given section.
2518    /// \note It is synonym of \c arcMapNames().
2519    const std::vector<std::string>& edgeMapNames(int i) const {
2520      return _edge_maps[i];
2521    }
2522
2523    /// @}
2524
2525    /// \name Attribute sections
2526    /// @{
2527
2528    /// \brief Gives back the number of attribute sections in the file.
2529    ///
2530    /// Gives back the number of attribute sections in the file.
2531    int attributeSectionNum() const {
2532      return _attribute_sections.size();
2533    }
2534
2535    /// \brief Returns the attribute section name at the given position.
2536    ///
2537    /// Returns the attribute section name at the given position.
2538    const std::string& attributeSectionNames(int i) const {
2539      return _attribute_sections[i];
2540    }
2541
2542    /// \brief Gives back the attributes for the given section.
2543    ///
2544    /// Gives back the attributes for the given section.
2545    const std::vector<std::string>& attributes(int i) const {
2546      return _attributes[i];
2547    }
2548
2549    /// @}
2550
2551    /// \name Extra sections
2552    /// @{
2553
2554    /// \brief Gives back the number of extra sections in the file.
2555    ///
2556    /// Gives back the number of extra sections in the file.
2557    int extraSectionNum() const {
2558      return _extra_sections.size();
2559    }
2560
2561    /// \brief Returns the extra section type at the given position.
2562    ///
2563    /// Returns the section type at the given position.
2564    const std::string& extraSection(int i) const {
2565      return _extra_sections[i];
2566    }
2567
2568    /// @}
2569
2570  private:
2571
2572    bool readLine() {
2573      std::string str;
2574      while(++line_num, std::getline(*_is, str)) {
2575        line.clear(); line.str(str);
2576        char c;
2577        if (line >> std::ws >> c && c != '#') {
2578          line.putback(c);
2579          return true;
2580        }
2581      }
2582      return false;
2583    }
2584
2585    bool readSuccess() {
2586      return static_cast<bool>(*_is);
2587    }
2588
2589    void skipSection() {
2590      char c;
2591      while (readSuccess() && line >> c && c != '@') {
2592        readLine();
2593      }
2594      if (readSuccess()) {
2595        line.putback(c);
2596      }
2597    }
2598
2599    void readMaps(std::vector<std::string>& maps) {
2600      char c;
2601      if (!readLine() || !(line >> c) || c == '@') {
2602        if (readSuccess() && line) line.putback(c);
2603        return;
2604      }
2605      line.putback(c);
2606      std::string map;
2607      while (_reader_bits::readToken(line, map)) {
2608        maps.push_back(map);
2609      }
2610    }
2611
2612    void readAttributes(std::vector<std::string>& attrs) {
2613      readLine();
2614      char c;
2615      while (readSuccess() && line >> c && c != '@') {
2616        line.putback(c);
2617        std::string attr;
2618        _reader_bits::readToken(line, attr);
2619        attrs.push_back(attr);
2620        readLine();
2621      }
2622      line.putback(c);
2623    }
2624
2625  public:
2626
2627    /// \name Execution of the contents reader
2628    /// @{
2629
2630    /// \brief Starts the reading
2631    ///
2632    /// This function starts the reading.
2633    void run() {
2634
2635      readLine();
2636      skipSection();
2637
2638      while (readSuccess()) {
2639
2640        char c;
2641        line >> c;
2642
2643        std::string section, caption;
2644        _reader_bits::readToken(line, section);
2645        _reader_bits::readToken(line, caption);
2646
2647        if (section == "nodes") {
2648          _node_sections.push_back(caption);
2649          _node_maps.push_back(std::vector<std::string>());
2650          readMaps(_node_maps.back());
2651          readLine(); skipSection();
2652        } else if (section == "arcs" || section == "edges") {
2653          _edge_sections.push_back(caption);
2654          _arc_sections.push_back(section == "arcs");
2655          _edge_maps.push_back(std::vector<std::string>());
2656          readMaps(_edge_maps.back());
2657          readLine(); skipSection();
2658        } else if (section == "attributes") {
2659          _attribute_sections.push_back(caption);
2660          _attributes.push_back(std::vector<std::string>());
2661          readAttributes(_attributes.back());
2662        } else {
2663          _extra_sections.push_back(section);
2664          readLine(); skipSection();
2665        }
2666      }
2667    }
2668
2669    /// @}
2670
2671  };
2672}
2673
2674#endif
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