COIN-OR::LEMON - Graph Library

source: lemon/lemon/lgf_reader.h @ 294:cbe3ec2d59d2

Last change on this file since 294:cbe3ec2d59d2 was 294:cbe3ec2d59d2, checked in by Alpar Juttner <alpar@…>, 11 years ago

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1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2008
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
12 *
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
15 * purpose.
16 *
17 */
18
19///\ingroup lemon_io
20///\file
21///\brief \ref lgf-format "LEMON Graph Format" reader.
22
23
24#ifndef LEMON_LGF_READER_H
25#define LEMON_LGF_READER_H
26
27#include <iostream>
28#include <fstream>
29#include <sstream>
30
31#include <set>
32#include <map>
33
34#include <lemon/assert.h>
35#include <lemon/core.h>
36
37#include <lemon/lgf_writer.h>
38
39#include <lemon/concept_check.h>
40#include <lemon/concepts/maps.h>
41
42namespace lemon {
43
44  namespace _reader_bits {
45
46    template <typename Value>
47    struct DefaultConverter {
48      Value operator()(const std::string& str) {
49        std::istringstream is(str);
50        Value value;
51        if (!(is >> value)) {
52          throw FormatError("Cannot read token");
53        }
54
55        char c;
56        if (is >> std::ws >> c) {
57          throw FormatError("Remaining characters in token");
58        }
59        return value;
60      }
61    };
62
63    template <>
64    struct DefaultConverter<std::string> {
65      std::string operator()(const std::string& str) {
66        return str;
67      }
68    };
69
70    template <typename _Item>
71    class MapStorageBase {
72    public:
73      typedef _Item Item;
74
75    public:
76      MapStorageBase() {}
77      virtual ~MapStorageBase() {}
78
79      virtual void set(const Item& item, const std::string& value) = 0;
80
81    };
82
83    template <typename _Item, typename _Map,
84              typename _Converter = DefaultConverter<typename _Map::Value> >
85    class MapStorage : public MapStorageBase<_Item> {
86    public:
87      typedef _Map Map;
88      typedef _Converter Converter;
89      typedef _Item Item;
90
91    private:
92      Map& _map;
93      Converter _converter;
94
95    public:
96      MapStorage(Map& map, const Converter& converter = Converter())
97        : _map(map), _converter(converter) {}
98      virtual ~MapStorage() {}
99
100      virtual void set(const Item& item ,const std::string& value) {
101        _map.set(item, _converter(value));
102      }
103    };
104
105    template <typename _Graph, bool _dir, typename _Map,
106              typename _Converter = DefaultConverter<typename _Map::Value> >
107    class GraphArcMapStorage : public MapStorageBase<typename _Graph::Edge> {
108    public:
109      typedef _Map Map;
110      typedef _Converter Converter;
111      typedef _Graph Graph;
112      typedef typename Graph::Edge Item;
113      static const bool dir = _dir;
114
115    private:
116      const Graph& _graph;
117      Map& _map;
118      Converter _converter;
119
120    public:
121      GraphArcMapStorage(const Graph& graph, Map& map,
122                         const Converter& converter = Converter())
123        : _graph(graph), _map(map), _converter(converter) {}
124      virtual ~GraphArcMapStorage() {}
125
126      virtual void set(const Item& item ,const std::string& value) {
127        _map.set(_graph.direct(item, dir), _converter(value));
128      }
129    };
130
131    class ValueStorageBase {
132    public:
133      ValueStorageBase() {}
134      virtual ~ValueStorageBase() {}
135
136      virtual void set(const std::string&) = 0;
137    };
138
139    template <typename _Value, typename _Converter = DefaultConverter<_Value> >
140    class ValueStorage : public ValueStorageBase {
141    public:
142      typedef _Value Value;
143      typedef _Converter Converter;
144
145    private:
146      Value& _value;
147      Converter _converter;
148
149    public:
150      ValueStorage(Value& value, const Converter& converter = Converter())
151        : _value(value), _converter(converter) {}
152
153      virtual void set(const std::string& value) {
154        _value = _converter(value);
155      }
156    };
157
158    template <typename Value>
159    struct MapLookUpConverter {
160      const std::map<std::string, Value>& _map;
161
162      MapLookUpConverter(const std::map<std::string, Value>& map)
163        : _map(map) {}
164
165      Value operator()(const std::string& str) {
166        typename std::map<std::string, Value>::const_iterator it =
167          _map.find(str);
168        if (it == _map.end()) {
169          std::ostringstream msg;
170          msg << "Item not found: " << str;
171          throw FormatError(msg.str());
172        }
173        return it->second;
174      }
175    };
176
177    template <typename Graph>
178    struct GraphArcLookUpConverter {
179      const Graph& _graph;
180      const std::map<std::string, typename Graph::Edge>& _map;
181
182      GraphArcLookUpConverter(const Graph& graph,
183                              const std::map<std::string,
184                                             typename Graph::Edge>& map)
185        : _graph(graph), _map(map) {}
186
187      typename Graph::Arc operator()(const std::string& str) {
188        if (str.empty() || (str[0] != '+' && str[0] != '-')) {
189          throw FormatError("Item must start with '+' or '-'");
190        }
191        typename std::map<std::string, typename Graph::Edge>
192          ::const_iterator it = _map.find(str.substr(1));
193        if (it == _map.end()) {
194          throw FormatError("Item not found");
195        }
196        return _graph.direct(it->second, str[0] == '+');
197      }
198    };
199
200    inline bool isWhiteSpace(char c) {
201      return c == ' ' || c == '\t' || c == '\v' ||
202        c == '\n' || c == '\r' || c == '\f';
203    }
204
205    inline bool isOct(char c) {
206      return '0' <= c && c <='7';
207    }
208
209    inline int valueOct(char c) {
210      LEMON_ASSERT(isOct(c), "The character is not octal.");
211      return c - '0';
212    }
213
214    inline bool isHex(char c) {
215      return ('0' <= c && c <= '9') ||
216        ('a' <= c && c <= 'z') ||
217        ('A' <= c && c <= 'Z');
218    }
219
220    inline int valueHex(char c) {
221      LEMON_ASSERT(isHex(c), "The character is not hexadecimal.");
222      if ('0' <= c && c <= '9') return c - '0';
223      if ('a' <= c && c <= 'z') return c - 'a' + 10;
224      return c - 'A' + 10;
225    }
226
227    inline bool isIdentifierFirstChar(char c) {
228      return ('a' <= c && c <= 'z') ||
229        ('A' <= c && c <= 'Z') || c == '_';
230    }
231
232    inline bool isIdentifierChar(char c) {
233      return isIdentifierFirstChar(c) ||
234        ('0' <= c && c <= '9');
235    }
236
237    inline char readEscape(std::istream& is) {
238      char c;
239      if (!is.get(c))
240        throw FormatError("Escape format error");
241
242      switch (c) {
243      case '\\':
244        return '\\';
245      case '\"':
246        return '\"';
247      case '\'':
248        return '\'';
249      case '\?':
250        return '\?';
251      case 'a':
252        return '\a';
253      case 'b':
254        return '\b';
255      case 'f':
256        return '\f';
257      case 'n':
258        return '\n';
259      case 'r':
260        return '\r';
261      case 't':
262        return '\t';
263      case 'v':
264        return '\v';
265      case 'x':
266        {
267          int code;
268          if (!is.get(c) || !isHex(c))
269            throw FormatError("Escape format error");
270          else if (code = valueHex(c), !is.get(c) || !isHex(c)) is.putback(c);
271          else code = code * 16 + valueHex(c);
272          return code;
273        }
274      default:
275        {
276          int code;
277          if (!isOct(c))
278            throw FormatError("Escape format error");
279          else if (code = valueOct(c), !is.get(c) || !isOct(c))
280            is.putback(c);
281          else if (code = code * 8 + valueOct(c), !is.get(c) || !isOct(c))
282            is.putback(c);
283          else code = code * 8 + valueOct(c);
284          return code;
285        }
286      }
287    }
288
289    inline std::istream& readToken(std::istream& is, std::string& str) {
290      std::ostringstream os;
291
292      char c;
293      is >> std::ws;
294
295      if (!is.get(c))
296        return is;
297
298      if (c == '\"') {
299        while (is.get(c) && c != '\"') {
300          if (c == '\\')
301            c = readEscape(is);
302          os << c;
303        }
304        if (!is)
305          throw FormatError("Quoted format error");
306      } else {
307        is.putback(c);
308        while (is.get(c) && !isWhiteSpace(c)) {
309          if (c == '\\')
310            c = readEscape(is);
311          os << c;
312        }
313        if (!is) {
314          is.clear();
315        } else {
316          is.putback(c);
317        }
318      }
319      str = os.str();
320      return is;
321    }
322
323    class Section {
324    public:
325      virtual ~Section() {}
326      virtual void process(std::istream& is, int& line_num) = 0;
327    };
328
329    template <typename Functor>
330    class LineSection : public Section {
331    private:
332
333      Functor _functor;
334
335    public:
336
337      LineSection(const Functor& functor) : _functor(functor) {}
338      virtual ~LineSection() {}
339
340      virtual void process(std::istream& is, int& line_num) {
341        char c;
342        std::string line;
343        while (is.get(c) && c != '@') {
344          if (c == '\n') {
345            ++line_num;
346          } else if (c == '#') {
347            getline(is, line);
348            ++line_num;
349          } else if (!isWhiteSpace(c)) {
350            is.putback(c);
351            getline(is, line);
352            _functor(line);
353            ++line_num;
354          }
355        }
356        if (is) is.putback(c);
357        else if (is.eof()) is.clear();
358      }
359    };
360
361    template <typename Functor>
362    class StreamSection : public Section {
363    private:
364
365      Functor _functor;
366
367    public:
368
369      StreamSection(const Functor& functor) : _functor(functor) {}
370      virtual ~StreamSection() {}
371
372      virtual void process(std::istream& is, int& line_num) {
373        _functor(is, line_num);
374        char c;
375        std::string line;
376        while (is.get(c) && c != '@') {
377          if (c == '\n') {
378            ++line_num;
379          } else if (!isWhiteSpace(c)) {
380            getline(is, line);
381            ++line_num;
382          }
383        }
384        if (is) is.putback(c);
385        else if (is.eof()) is.clear();
386      }
387    };
388
389  }
390
391  template <typename Digraph>
392  class DigraphReader;
393
394  template <typename Digraph>
395  DigraphReader<Digraph> digraphReader(Digraph& digraph,
396                                       std::istream& is = std::cin);
397
398  template <typename Digraph>
399  DigraphReader<Digraph> digraphReader(Digraph& digraph, const std::string& fn);
400
401  template <typename Digraph>
402  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char *fn);
403
404  /// \ingroup lemon_io
405  ///
406  /// \brief \ref lgf-format "LGF" reader for directed graphs
407  ///
408  /// This utility reads an \ref lgf-format "LGF" file.
409  ///
410  /// The reading method does a batch processing. The user creates a
411  /// reader object, then various reading rules can be added to the
412  /// reader, and eventually the reading is executed with the \c run()
413  /// member function. A map reading rule can be added to the reader
414  /// with the \c nodeMap() or \c arcMap() members. An optional
415  /// converter parameter can also be added as a standard functor
416  /// converting from \c std::string to the value type of the map. If it
417  /// is set, it will determine how the tokens in the file should be
418  /// converted to the value type of the map. If the functor is not set,
419  /// then a default conversion will be used. One map can be read into
420  /// multiple map objects at the same time. The \c attribute(), \c
421  /// node() and \c arc() functions are used to add attribute reading
422  /// rules.
423  ///
424  ///\code
425  /// DigraphReader<Digraph>(digraph, std::cin).
426  ///   nodeMap("coordinates", coord_map).
427  ///   arcMap("capacity", cap_map).
428  ///   node("source", src).
429  ///   node("target", trg).
430  ///   attribute("caption", caption).
431  ///   run();
432  ///\endcode
433  ///
434  /// By default the reader uses the first section in the file of the
435  /// proper type. If a section has an optional name, then it can be
436  /// selected for reading by giving an optional name parameter to the
437  /// \c nodes(), \c arcs() or \c attributes() functions.
438  ///
439  /// The \c useNodes() and \c useArcs() functions are used to tell the reader
440  /// that the nodes or arcs should not be constructed (added to the
441  /// graph) during the reading, but instead the label map of the items
442  /// are given as a parameter of these functions. An
443  /// application of these functions is multipass reading, which is
444  /// important if two \c \@arcs sections must be read from the
445  /// file. In this case the first phase would read the node set and one
446  /// of the arc sets, while the second phase would read the second arc
447  /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
448  /// The previously read label node map should be passed to the \c
449  /// useNodes() functions. Another application of multipass reading when
450  /// paths are given as a node map or an arc map.
451  /// It is impossible to read this in
452  /// a single pass, because the arcs are not constructed when the node
453  /// maps are read.
454  template <typename _Digraph>
455  class DigraphReader {
456  public:
457
458    typedef _Digraph Digraph;
459    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
460
461  private:
462
463
464    std::istream* _is;
465    bool local_is;
466    std::string _filename;
467
468    Digraph& _digraph;
469
470    std::string _nodes_caption;
471    std::string _arcs_caption;
472    std::string _attributes_caption;
473
474    typedef std::map<std::string, Node> NodeIndex;
475    NodeIndex _node_index;
476    typedef std::map<std::string, Arc> ArcIndex;
477    ArcIndex _arc_index;
478
479    typedef std::vector<std::pair<std::string,
480      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
481    NodeMaps _node_maps;
482
483    typedef std::vector<std::pair<std::string,
484      _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
485    ArcMaps _arc_maps;
486
487    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
488      Attributes;
489    Attributes _attributes;
490
491    bool _use_nodes;
492    bool _use_arcs;
493
494    bool _skip_nodes;
495    bool _skip_arcs;
496
497    int line_num;
498    std::istringstream line;
499
500  public:
501
502    /// \brief Constructor
503    ///
504    /// Construct a directed graph reader, which reads from the given
505    /// input stream.
506    DigraphReader(Digraph& digraph, std::istream& is = std::cin)
507      : _is(&is), local_is(false), _digraph(digraph),
508        _use_nodes(false), _use_arcs(false),
509        _skip_nodes(false), _skip_arcs(false) {}
510
511    /// \brief Constructor
512    ///
513    /// Construct a directed graph reader, which reads from the given
514    /// file.
515    DigraphReader(Digraph& digraph, const std::string& fn)
516      : _is(new std::ifstream(fn.c_str())), local_is(true),
517        _filename(fn), _digraph(digraph),
518        _use_nodes(false), _use_arcs(false),
519        _skip_nodes(false), _skip_arcs(false) {
520      if (!(*_is)) throw IoError("Cannot open file", fn);
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)) throw IoError("Cannot open file", fn);
533    }
534
535    /// \brief Destructor
536    ~DigraphReader() {
537      for (typename NodeMaps::iterator it = _node_maps.begin();
538           it != _node_maps.end(); ++it) {
539        delete it->second;
540      }
541
542      for (typename ArcMaps::iterator it = _arc_maps.begin();
543           it != _arc_maps.end(); ++it) {
544        delete it->second;
545      }
546
547      for (typename Attributes::iterator it = _attributes.begin();
548           it != _attributes.end(); ++it) {
549        delete it->second;
550      }
551
552      if (local_is) {
553        delete _is;
554      }
555
556    }
557
558  private:
559
560    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
561                                                  std::istream& is);
562    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
563                                                  const std::string& fn);
564    friend DigraphReader<Digraph> digraphReader<>(Digraph& digraph,
565                                                  const char *fn);
566
567    DigraphReader(DigraphReader& other)
568      : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
569        _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
570        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
571
572      other._is = 0;
573      other.local_is = false;
574
575      _node_index.swap(other._node_index);
576      _arc_index.swap(other._arc_index);
577
578      _node_maps.swap(other._node_maps);
579      _arc_maps.swap(other._arc_maps);
580      _attributes.swap(other._attributes);
581
582      _nodes_caption = other._nodes_caption;
583      _arcs_caption = other._arcs_caption;
584      _attributes_caption = other._attributes_caption;
585
586    }
587
588    DigraphReader& operator=(const DigraphReader&);
589
590  public:
591
592    /// \name Reading rules
593    /// @{
594
595    /// \brief Node map reading rule
596    ///
597    /// Add a node map reading rule to the reader.
598    template <typename Map>
599    DigraphReader& nodeMap(const std::string& caption, Map& map) {
600      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
601      _reader_bits::MapStorageBase<Node>* storage =
602        new _reader_bits::MapStorage<Node, Map>(map);
603      _node_maps.push_back(std::make_pair(caption, storage));
604      return *this;
605    }
606
607    /// \brief Node map reading rule
608    ///
609    /// Add a node map reading rule with specialized converter to the
610    /// reader.
611    template <typename Map, typename Converter>
612    DigraphReader& nodeMap(const std::string& caption, Map& map,
613                           const Converter& converter = Converter()) {
614      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
615      _reader_bits::MapStorageBase<Node>* storage =
616        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
617      _node_maps.push_back(std::make_pair(caption, storage));
618      return *this;
619    }
620
621    /// \brief Arc map reading rule
622    ///
623    /// Add an arc map reading rule to the reader.
624    template <typename Map>
625    DigraphReader& arcMap(const std::string& caption, Map& map) {
626      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
627      _reader_bits::MapStorageBase<Arc>* storage =
628        new _reader_bits::MapStorage<Arc, Map>(map);
629      _arc_maps.push_back(std::make_pair(caption, storage));
630      return *this;
631    }
632
633    /// \brief Arc map reading rule
634    ///
635    /// Add an arc map reading rule with specialized converter to the
636    /// reader.
637    template <typename Map, typename Converter>
638    DigraphReader& arcMap(const std::string& caption, Map& map,
639                          const Converter& converter = Converter()) {
640      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
641      _reader_bits::MapStorageBase<Arc>* storage =
642        new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
643      _arc_maps.push_back(std::make_pair(caption, storage));
644      return *this;
645    }
646
647    /// \brief Attribute reading rule
648    ///
649    /// Add an attribute reading rule to the reader.
650    template <typename Value>
651    DigraphReader& attribute(const std::string& caption, Value& value) {
652      _reader_bits::ValueStorageBase* storage =
653        new _reader_bits::ValueStorage<Value>(value);
654      _attributes.insert(std::make_pair(caption, storage));
655      return *this;
656    }
657
658    /// \brief Attribute reading rule
659    ///
660    /// Add an attribute reading rule with specialized converter to the
661    /// reader.
662    template <typename Value, typename Converter>
663    DigraphReader& attribute(const std::string& caption, Value& value,
664                             const Converter& converter = Converter()) {
665      _reader_bits::ValueStorageBase* storage =
666        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
667      _attributes.insert(std::make_pair(caption, storage));
668      return *this;
669    }
670
671    /// \brief Node reading rule
672    ///
673    /// Add a node reading rule to reader.
674    DigraphReader& node(const std::string& caption, Node& node) {
675      typedef _reader_bits::MapLookUpConverter<Node> Converter;
676      Converter converter(_node_index);
677      _reader_bits::ValueStorageBase* storage =
678        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
679      _attributes.insert(std::make_pair(caption, storage));
680      return *this;
681    }
682
683    /// \brief Arc reading rule
684    ///
685    /// Add an arc reading rule to reader.
686    DigraphReader& arc(const std::string& caption, Arc& arc) {
687      typedef _reader_bits::MapLookUpConverter<Arc> Converter;
688      Converter converter(_arc_index);
689      _reader_bits::ValueStorageBase* storage =
690        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
691      _attributes.insert(std::make_pair(caption, storage));
692      return *this;
693    }
694
695    /// @}
696
697    /// \name Select section by name
698    /// @{
699
700    /// \brief Set \c \@nodes section to be read
701    ///
702    /// Set \c \@nodes section to be read
703    DigraphReader& nodes(const std::string& caption) {
704      _nodes_caption = caption;
705      return *this;
706    }
707
708    /// \brief Set \c \@arcs section to be read
709    ///
710    /// Set \c \@arcs section to be read
711    DigraphReader& arcs(const std::string& caption) {
712      _arcs_caption = caption;
713      return *this;
714    }
715
716    /// \brief Set \c \@attributes section to be read
717    ///
718    /// Set \c \@attributes section to be read
719    DigraphReader& attributes(const std::string& caption) {
720      _attributes_caption = caption;
721      return *this;
722    }
723
724    /// @}
725
726    /// \name Using previously constructed node or arc set
727    /// @{
728
729    /// \brief Use previously constructed node set
730    ///
731    /// Use previously constructed node set, and specify the node
732    /// label map.
733    template <typename Map>
734    DigraphReader& useNodes(const Map& map) {
735      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
736      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
737      _use_nodes = true;
738      _writer_bits::DefaultConverter<typename Map::Value> converter;
739      for (NodeIt n(_digraph); n != INVALID; ++n) {
740        _node_index.insert(std::make_pair(converter(map[n]), n));
741      }
742      return *this;
743    }
744
745    /// \brief Use previously constructed node set
746    ///
747    /// Use previously constructed node set, and specify the node
748    /// label map and a functor which converts the label map values to
749    /// \c std::string.
750    template <typename Map, typename Converter>
751    DigraphReader& useNodes(const Map& map,
752                            const Converter& converter = Converter()) {
753      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
754      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
755      _use_nodes = true;
756      for (NodeIt n(_digraph); n != INVALID; ++n) {
757        _node_index.insert(std::make_pair(converter(map[n]), n));
758      }
759      return *this;
760    }
761
762    /// \brief Use previously constructed arc set
763    ///
764    /// Use previously constructed arc set, and specify the arc
765    /// label map.
766    template <typename Map>
767    DigraphReader& useArcs(const Map& map) {
768      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
769      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
770      _use_arcs = true;
771      _writer_bits::DefaultConverter<typename Map::Value> converter;
772      for (ArcIt a(_digraph); a != INVALID; ++a) {
773        _arc_index.insert(std::make_pair(converter(map[a]), a));
774      }
775      return *this;
776    }
777
778    /// \brief Use previously constructed arc set
779    ///
780    /// Use previously constructed arc set, and specify the arc
781    /// label map and a functor which converts the label map values to
782    /// \c std::string.
783    template <typename Map, typename Converter>
784    DigraphReader& useArcs(const Map& map,
785                           const Converter& converter = Converter()) {
786      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
787      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
788      _use_arcs = true;
789      for (ArcIt a(_digraph); a != INVALID; ++a) {
790        _arc_index.insert(std::make_pair(converter(map[a]), a));
791      }
792      return *this;
793    }
794
795    /// \brief Skips the reading of node section
796    ///
797    /// Omit the reading of the node section. This implies that each node
798    /// map reading rule will be abandoned, and the nodes of the graph
799    /// will not be constructed, which usually cause that the arc set
800    /// could not be read due to lack of node name resolving.
801    /// Therefore \c skipArcs() function should also be used, or
802    /// \c useNodes() should be used to specify the label of the nodes.
803    DigraphReader& skipNodes() {
804      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
805      _skip_nodes = true;
806      return *this;
807    }
808
809    /// \brief Skips the reading of arc section
810    ///
811    /// Omit the reading of the arc section. This implies that each arc
812    /// map reading rule will be abandoned, and the arcs of the graph
813    /// will not be constructed.
814    DigraphReader& skipArcs() {
815      LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
816      _skip_arcs = true;
817      return *this;
818    }
819
820    /// @}
821
822  private:
823
824    bool readLine() {
825      std::string str;
826      while(++line_num, std::getline(*_is, str)) {
827        line.clear(); line.str(str);
828        char c;
829        if (line >> std::ws >> c && c != '#') {
830          line.putback(c);
831          return true;
832        }
833      }
834      return false;
835    }
836
837    bool readSuccess() {
838      return static_cast<bool>(*_is);
839    }
840
841    void skipSection() {
842      char c;
843      while (readSuccess() && line >> c && c != '@') {
844        readLine();
845      }
846      line.putback(c);
847    }
848
849    void readNodes() {
850
851      std::vector<int> map_index(_node_maps.size());
852      int map_num, label_index;
853
854      char c;
855      if (!readLine() || !(line >> c) || c == '@') {
856        if (readSuccess() && line) line.putback(c);
857        if (!_node_maps.empty())
858          throw FormatError("Cannot find map names");
859        return;
860      }
861      line.putback(c);
862
863      {
864        std::map<std::string, int> maps;
865
866        std::string map;
867        int index = 0;
868        while (_reader_bits::readToken(line, map)) {
869          if (maps.find(map) != maps.end()) {
870            std::ostringstream msg;
871            msg << "Multiple occurence of node map: " << map;
872            throw FormatError(msg.str());
873          }
874          maps.insert(std::make_pair(map, index));
875          ++index;
876        }
877
878        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
879          std::map<std::string, int>::iterator jt =
880            maps.find(_node_maps[i].first);
881          if (jt == maps.end()) {
882            std::ostringstream msg;
883            msg << "Map not found: " << _node_maps[i].first;
884            throw FormatError(msg.str());
885          }
886          map_index[i] = jt->second;
887        }
888
889        {
890          std::map<std::string, int>::iterator jt = maps.find("label");
891          if (jt != maps.end()) {
892            label_index = jt->second;
893          } else {
894            label_index = -1;
895          }
896        }
897        map_num = maps.size();
898      }
899
900      while (readLine() && line >> c && c != '@') {
901        line.putback(c);
902
903        std::vector<std::string> tokens(map_num);
904        for (int i = 0; i < map_num; ++i) {
905          if (!_reader_bits::readToken(line, tokens[i])) {
906            std::ostringstream msg;
907            msg << "Column not found (" << i + 1 << ")";
908            throw FormatError(msg.str());
909          }
910        }
911        if (line >> std::ws >> c)
912          throw FormatError("Extra character at the end of line");
913
914        Node n;
915        if (!_use_nodes) {
916          n = _digraph.addNode();
917          if (label_index != -1)
918            _node_index.insert(std::make_pair(tokens[label_index], n));
919        } else {
920          if (label_index == -1)
921            throw FormatError("Label map not found");
922          typename std::map<std::string, Node>::iterator it =
923            _node_index.find(tokens[label_index]);
924          if (it == _node_index.end()) {
925            std::ostringstream msg;
926            msg << "Node with label not found: " << tokens[label_index];
927            throw FormatError(msg.str());
928          }
929          n = it->second;
930        }
931
932        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
933          _node_maps[i].second->set(n, tokens[map_index[i]]);
934        }
935
936      }
937      if (readSuccess()) {
938        line.putback(c);
939      }
940    }
941
942    void readArcs() {
943
944      std::vector<int> map_index(_arc_maps.size());
945      int map_num, label_index;
946
947      char c;
948      if (!readLine() || !(line >> c) || c == '@') {
949        if (readSuccess() && line) line.putback(c);
950        if (!_arc_maps.empty())
951          throw FormatError("Cannot find map names");
952        return;
953      }
954      line.putback(c);
955
956      {
957        std::map<std::string, int> maps;
958
959        std::string map;
960        int index = 0;
961        while (_reader_bits::readToken(line, map)) {
962          if (maps.find(map) != maps.end()) {
963            std::ostringstream msg;
964            msg << "Multiple occurence of arc map: " << map;
965            throw FormatError(msg.str());
966          }
967          maps.insert(std::make_pair(map, index));
968          ++index;
969        }
970
971        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
972          std::map<std::string, int>::iterator jt =
973            maps.find(_arc_maps[i].first);
974          if (jt == maps.end()) {
975            std::ostringstream msg;
976            msg << "Map not found: " << _arc_maps[i].first;
977            throw FormatError(msg.str());
978          }
979          map_index[i] = jt->second;
980        }
981
982        {
983          std::map<std::string, int>::iterator jt = maps.find("label");
984          if (jt != maps.end()) {
985            label_index = jt->second;
986          } else {
987            label_index = -1;
988          }
989        }
990        map_num = maps.size();
991      }
992
993      while (readLine() && line >> c && c != '@') {
994        line.putback(c);
995
996        std::string source_token;
997        std::string target_token;
998
999        if (!_reader_bits::readToken(line, source_token))
1000          throw FormatError("Source not found");
1001
1002        if (!_reader_bits::readToken(line, target_token))
1003          throw FormatError("Target not found");
1004
1005        std::vector<std::string> tokens(map_num);
1006        for (int i = 0; i < map_num; ++i) {
1007          if (!_reader_bits::readToken(line, tokens[i])) {
1008            std::ostringstream msg;
1009            msg << "Column not found (" << i + 1 << ")";
1010            throw FormatError(msg.str());
1011          }
1012        }
1013        if (line >> std::ws >> c)
1014          throw FormatError("Extra character at the end of line");
1015
1016        Arc a;
1017        if (!_use_arcs) {
1018
1019          typename NodeIndex::iterator it;
1020
1021          it = _node_index.find(source_token);
1022          if (it == _node_index.end()) {
1023            std::ostringstream msg;
1024            msg << "Item not found: " << source_token;
1025            throw FormatError(msg.str());
1026          }
1027          Node source = it->second;
1028
1029          it = _node_index.find(target_token);
1030          if (it == _node_index.end()) {
1031            std::ostringstream msg;
1032            msg << "Item not found: " << target_token;
1033            throw FormatError(msg.str());
1034          }
1035          Node target = it->second;
1036
1037          a = _digraph.addArc(source, target);
1038          if (label_index != -1)
1039            _arc_index.insert(std::make_pair(tokens[label_index], a));
1040        } else {
1041          if (label_index == -1)
1042            throw FormatError("Label map not found");
1043          typename std::map<std::string, Arc>::iterator it =
1044            _arc_index.find(tokens[label_index]);
1045          if (it == _arc_index.end()) {
1046            std::ostringstream msg;
1047            msg << "Arc with label not found: " << tokens[label_index];
1048            throw FormatError(msg.str());
1049          }
1050          a = it->second;
1051        }
1052
1053        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
1054          _arc_maps[i].second->set(a, tokens[map_index[i]]);
1055        }
1056
1057      }
1058      if (readSuccess()) {
1059        line.putback(c);
1060      }
1061    }
1062
1063    void readAttributes() {
1064
1065      std::set<std::string> read_attr;
1066
1067      char c;
1068      while (readLine() && line >> c && c != '@') {
1069        line.putback(c);
1070
1071        std::string attr, token;
1072        if (!_reader_bits::readToken(line, attr))
1073          throw FormatError("Attribute name not found");
1074        if (!_reader_bits::readToken(line, token))
1075          throw FormatError("Attribute value not found");
1076        if (line >> c)
1077          throw FormatError("Extra character at the end of line");
1078
1079        {
1080          std::set<std::string>::iterator it = read_attr.find(attr);
1081          if (it != read_attr.end()) {
1082            std::ostringstream msg;
1083            msg << "Multiple occurence of attribute: " << attr;
1084            throw FormatError(msg.str());
1085          }
1086          read_attr.insert(attr);
1087        }
1088
1089        {
1090          typename Attributes::iterator it = _attributes.lower_bound(attr);
1091          while (it != _attributes.end() && it->first == attr) {
1092            it->second->set(token);
1093            ++it;
1094          }
1095        }
1096
1097      }
1098      if (readSuccess()) {
1099        line.putback(c);
1100      }
1101      for (typename Attributes::iterator it = _attributes.begin();
1102           it != _attributes.end(); ++it) {
1103        if (read_attr.find(it->first) == read_attr.end()) {
1104          std::ostringstream msg;
1105          msg << "Attribute not found: " << it->first;
1106          throw FormatError(msg.str());
1107        }
1108      }
1109    }
1110
1111  public:
1112
1113    /// \name Execution of the reader
1114    /// @{
1115
1116    /// \brief Start the batch processing
1117    ///
1118    /// This function starts the batch processing
1119    void run() {
1120      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1121
1122      bool nodes_done = _skip_nodes;
1123      bool arcs_done = _skip_arcs;
1124      bool attributes_done = false;
1125
1126      line_num = 0;
1127      readLine();
1128      skipSection();
1129
1130      while (readSuccess()) {
1131        try {
1132          char c;
1133          std::string section, caption;
1134          line >> c;
1135          _reader_bits::readToken(line, section);
1136          _reader_bits::readToken(line, caption);
1137
1138          if (line >> c)
1139            throw FormatError("Extra character at the end of line");
1140
1141          if (section == "nodes" && !nodes_done) {
1142            if (_nodes_caption.empty() || _nodes_caption == caption) {
1143              readNodes();
1144              nodes_done = true;
1145            }
1146          } else if ((section == "arcs" || section == "edges") &&
1147                     !arcs_done) {
1148            if (_arcs_caption.empty() || _arcs_caption == caption) {
1149              readArcs();
1150              arcs_done = true;
1151            }
1152          } else if (section == "attributes" && !attributes_done) {
1153            if (_attributes_caption.empty() || _attributes_caption == caption) {
1154              readAttributes();
1155              attributes_done = true;
1156            }
1157          } else {
1158            readLine();
1159            skipSection();
1160          }
1161        } catch (FormatError& error) {
1162          error.line(line_num);
1163          error.file(_filename);
1164          throw;
1165        }
1166      }
1167
1168      if (!nodes_done) {
1169        throw FormatError("Section @nodes not found");
1170      }
1171
1172      if (!arcs_done) {
1173        throw FormatError("Section @arcs not found");
1174      }
1175
1176      if (!attributes_done && !_attributes.empty()) {
1177        throw FormatError("Section @attributes not found");
1178      }
1179
1180    }
1181
1182    /// @}
1183
1184  };
1185
1186  /// \brief Return a \ref DigraphReader class
1187  ///
1188  /// This function just returns a \ref DigraphReader class.
1189  /// \relates DigraphReader
1190  template <typename Digraph>
1191  DigraphReader<Digraph> digraphReader(Digraph& digraph,
1192                                       std::istream& is = std::cin) {
1193    DigraphReader<Digraph> tmp(digraph, is);
1194    return tmp;
1195  }
1196
1197  /// \brief Return a \ref DigraphReader class
1198  ///
1199  /// This function just returns a \ref DigraphReader class.
1200  /// \relates DigraphReader
1201  template <typename Digraph>
1202  DigraphReader<Digraph> digraphReader(Digraph& digraph,
1203                                       const std::string& fn) {
1204    DigraphReader<Digraph> tmp(digraph, fn);
1205    return tmp;
1206  }
1207
1208  /// \brief Return a \ref DigraphReader class
1209  ///
1210  /// This function just returns a \ref DigraphReader class.
1211  /// \relates DigraphReader
1212  template <typename Digraph>
1213  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char* fn) {
1214    DigraphReader<Digraph> tmp(digraph, fn);
1215    return tmp;
1216  }
1217
1218  template <typename Graph>
1219  class GraphReader;
1220
1221  template <typename Graph>
1222  GraphReader<Graph> graphReader(Graph& graph,
1223                                 std::istream& is = std::cin);
1224
1225  template <typename Graph>
1226  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn);
1227
1228  template <typename Graph>
1229  GraphReader<Graph> graphReader(Graph& graph, const char *fn);
1230
1231  /// \ingroup lemon_io
1232  ///
1233  /// \brief \ref lgf-format "LGF" reader for undirected graphs
1234  ///
1235  /// This utility reads an \ref lgf-format "LGF" file.
1236  ///
1237  /// It can be used almost the same way as \c DigraphReader.
1238  /// The only difference is that this class can handle edges and
1239  /// edge maps as well as arcs and arc maps.
1240  ///
1241  /// The columns in the \c \@edges (or \c \@arcs) section are the
1242  /// edge maps. However, if there are two maps with the same name
1243  /// prefixed with \c '+' and \c '-', then these can be read into an
1244  /// arc map.  Similarly, an attribute can be read into an arc, if
1245  /// it's value is an edge label prefixed with \c '+' or \c '-'.
1246  template <typename _Graph>
1247  class GraphReader {
1248  public:
1249
1250    typedef _Graph Graph;
1251    TEMPLATE_GRAPH_TYPEDEFS(Graph);
1252
1253  private:
1254
1255    std::istream* _is;
1256    bool local_is;
1257    std::string _filename;
1258
1259    Graph& _graph;
1260
1261    std::string _nodes_caption;
1262    std::string _edges_caption;
1263    std::string _attributes_caption;
1264
1265    typedef std::map<std::string, Node> NodeIndex;
1266    NodeIndex _node_index;
1267    typedef std::map<std::string, Edge> EdgeIndex;
1268    EdgeIndex _edge_index;
1269
1270    typedef std::vector<std::pair<std::string,
1271      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
1272    NodeMaps _node_maps;
1273
1274    typedef std::vector<std::pair<std::string,
1275      _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
1276    EdgeMaps _edge_maps;
1277
1278    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
1279      Attributes;
1280    Attributes _attributes;
1281
1282    bool _use_nodes;
1283    bool _use_edges;
1284
1285    bool _skip_nodes;
1286    bool _skip_edges;
1287
1288    int line_num;
1289    std::istringstream line;
1290
1291  public:
1292
1293    /// \brief Constructor
1294    ///
1295    /// Construct an undirected graph reader, which reads from the given
1296    /// input stream.
1297    GraphReader(Graph& graph, std::istream& is = std::cin)
1298      : _is(&is), local_is(false), _graph(graph),
1299        _use_nodes(false), _use_edges(false),
1300        _skip_nodes(false), _skip_edges(false) {}
1301
1302    /// \brief Constructor
1303    ///
1304    /// Construct an undirected graph reader, which reads from the given
1305    /// file.
1306    GraphReader(Graph& graph, const std::string& fn)
1307      : _is(new std::ifstream(fn.c_str())), local_is(true),
1308        _filename(fn), _graph(graph),
1309        _use_nodes(false), _use_edges(false),
1310        _skip_nodes(false), _skip_edges(false) {
1311      if (!(*_is)) throw IoError("Cannot open file", fn);
1312    }
1313
1314    /// \brief Constructor
1315    ///
1316    /// Construct an undirected graph reader, which reads from the given
1317    /// file.
1318    GraphReader(Graph& graph, const char* fn)
1319      : _is(new std::ifstream(fn)), local_is(true),
1320        _filename(fn), _graph(graph),
1321        _use_nodes(false), _use_edges(false),
1322        _skip_nodes(false), _skip_edges(false) {
1323      if (!(*_is)) throw IoError("Cannot open file", fn);
1324    }
1325
1326    /// \brief Destructor
1327    ~GraphReader() {
1328      for (typename NodeMaps::iterator it = _node_maps.begin();
1329           it != _node_maps.end(); ++it) {
1330        delete it->second;
1331      }
1332
1333      for (typename EdgeMaps::iterator it = _edge_maps.begin();
1334           it != _edge_maps.end(); ++it) {
1335        delete it->second;
1336      }
1337
1338      for (typename Attributes::iterator it = _attributes.begin();
1339           it != _attributes.end(); ++it) {
1340        delete it->second;
1341      }
1342
1343      if (local_is) {
1344        delete _is;
1345      }
1346
1347    }
1348
1349  private:
1350    friend GraphReader<Graph> graphReader<>(Graph& graph, std::istream& is);
1351    friend GraphReader<Graph> graphReader<>(Graph& graph,
1352                                            const std::string& fn);
1353    friend GraphReader<Graph> graphReader<>(Graph& graph, const char *fn);
1354
1355    GraphReader(GraphReader& other)
1356      : _is(other._is), local_is(other.local_is), _graph(other._graph),
1357        _use_nodes(other._use_nodes), _use_edges(other._use_edges),
1358        _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
1359
1360      other._is = 0;
1361      other.local_is = false;
1362
1363      _node_index.swap(other._node_index);
1364      _edge_index.swap(other._edge_index);
1365
1366      _node_maps.swap(other._node_maps);
1367      _edge_maps.swap(other._edge_maps);
1368      _attributes.swap(other._attributes);
1369
1370      _nodes_caption = other._nodes_caption;
1371      _edges_caption = other._edges_caption;
1372      _attributes_caption = other._attributes_caption;
1373
1374    }
1375
1376    GraphReader& operator=(const GraphReader&);
1377
1378  public:
1379
1380    /// \name Reading rules
1381    /// @{
1382
1383    /// \brief Node map reading rule
1384    ///
1385    /// Add a node map reading rule to the reader.
1386    template <typename Map>
1387    GraphReader& nodeMap(const std::string& caption, Map& map) {
1388      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1389      _reader_bits::MapStorageBase<Node>* storage =
1390        new _reader_bits::MapStorage<Node, Map>(map);
1391      _node_maps.push_back(std::make_pair(caption, storage));
1392      return *this;
1393    }
1394
1395    /// \brief Node map reading rule
1396    ///
1397    /// Add a node map reading rule with specialized converter to the
1398    /// reader.
1399    template <typename Map, typename Converter>
1400    GraphReader& nodeMap(const std::string& caption, Map& map,
1401                           const Converter& converter = Converter()) {
1402      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1403      _reader_bits::MapStorageBase<Node>* storage =
1404        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
1405      _node_maps.push_back(std::make_pair(caption, storage));
1406      return *this;
1407    }
1408
1409    /// \brief Edge map reading rule
1410    ///
1411    /// Add an edge map reading rule to the reader.
1412    template <typename Map>
1413    GraphReader& edgeMap(const std::string& caption, Map& map) {
1414      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1415      _reader_bits::MapStorageBase<Edge>* storage =
1416        new _reader_bits::MapStorage<Edge, Map>(map);
1417      _edge_maps.push_back(std::make_pair(caption, storage));
1418      return *this;
1419    }
1420
1421    /// \brief Edge map reading rule
1422    ///
1423    /// Add an edge map reading rule with specialized converter to the
1424    /// reader.
1425    template <typename Map, typename Converter>
1426    GraphReader& edgeMap(const std::string& caption, Map& map,
1427                          const Converter& converter = Converter()) {
1428      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1429      _reader_bits::MapStorageBase<Edge>* storage =
1430        new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
1431      _edge_maps.push_back(std::make_pair(caption, storage));
1432      return *this;
1433    }
1434
1435    /// \brief Arc map reading rule
1436    ///
1437    /// Add an arc map reading rule to the reader.
1438    template <typename Map>
1439    GraphReader& arcMap(const std::string& caption, Map& map) {
1440      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1441      _reader_bits::MapStorageBase<Edge>* forward_storage =
1442        new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
1443      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1444      _reader_bits::MapStorageBase<Edge>* backward_storage =
1445        new _reader_bits::GraphArcMapStorage<Graph, false, Map>(_graph, map);
1446      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1447      return *this;
1448    }
1449
1450    /// \brief Arc map reading rule
1451    ///
1452    /// Add an arc map reading rule with specialized converter to the
1453    /// reader.
1454    template <typename Map, typename Converter>
1455    GraphReader& arcMap(const std::string& caption, Map& map,
1456                          const Converter& converter = Converter()) {
1457      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1458      _reader_bits::MapStorageBase<Edge>* forward_storage =
1459        new _reader_bits::GraphArcMapStorage<Graph, true, Map, Converter>
1460        (_graph, map, converter);
1461      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1462      _reader_bits::MapStorageBase<Edge>* backward_storage =
1463        new _reader_bits::GraphArcMapStorage<Graph, false, Map, Converter>
1464        (_graph, map, converter);
1465      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1466      return *this;
1467    }
1468
1469    /// \brief Attribute reading rule
1470    ///
1471    /// Add an attribute reading rule to the reader.
1472    template <typename Value>
1473    GraphReader& attribute(const std::string& caption, Value& value) {
1474      _reader_bits::ValueStorageBase* storage =
1475        new _reader_bits::ValueStorage<Value>(value);
1476      _attributes.insert(std::make_pair(caption, storage));
1477      return *this;
1478    }
1479
1480    /// \brief Attribute reading rule
1481    ///
1482    /// Add an attribute reading rule with specialized converter to the
1483    /// reader.
1484    template <typename Value, typename Converter>
1485    GraphReader& attribute(const std::string& caption, Value& value,
1486                             const Converter& converter = Converter()) {
1487      _reader_bits::ValueStorageBase* storage =
1488        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
1489      _attributes.insert(std::make_pair(caption, storage));
1490      return *this;
1491    }
1492
1493    /// \brief Node reading rule
1494    ///
1495    /// Add a node reading rule to reader.
1496    GraphReader& node(const std::string& caption, Node& node) {
1497      typedef _reader_bits::MapLookUpConverter<Node> Converter;
1498      Converter converter(_node_index);
1499      _reader_bits::ValueStorageBase* storage =
1500        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
1501      _attributes.insert(std::make_pair(caption, storage));
1502      return *this;
1503    }
1504
1505    /// \brief Edge reading rule
1506    ///
1507    /// Add an edge reading rule to reader.
1508    GraphReader& edge(const std::string& caption, Edge& edge) {
1509      typedef _reader_bits::MapLookUpConverter<Edge> Converter;
1510      Converter converter(_edge_index);
1511      _reader_bits::ValueStorageBase* storage =
1512        new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
1513      _attributes.insert(std::make_pair(caption, storage));
1514      return *this;
1515    }
1516
1517    /// \brief Arc reading rule
1518    ///
1519    /// Add an arc reading rule to reader.
1520    GraphReader& arc(const std::string& caption, Arc& arc) {
1521      typedef _reader_bits::GraphArcLookUpConverter<Graph> Converter;
1522      Converter converter(_graph, _edge_index);
1523      _reader_bits::ValueStorageBase* storage =
1524        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
1525      _attributes.insert(std::make_pair(caption, storage));
1526      return *this;
1527    }
1528
1529    /// @}
1530
1531    /// \name Select section by name
1532    /// @{
1533
1534    /// \brief Set \c \@nodes section to be read
1535    ///
1536    /// Set \c \@nodes section to be read.
1537    GraphReader& nodes(const std::string& caption) {
1538      _nodes_caption = caption;
1539      return *this;
1540    }
1541
1542    /// \brief Set \c \@edges section to be read
1543    ///
1544    /// Set \c \@edges section to be read.
1545    GraphReader& edges(const std::string& caption) {
1546      _edges_caption = caption;
1547      return *this;
1548    }
1549
1550    /// \brief Set \c \@attributes section to be read
1551    ///
1552    /// Set \c \@attributes section to be read.
1553    GraphReader& attributes(const std::string& caption) {
1554      _attributes_caption = caption;
1555      return *this;
1556    }
1557
1558    /// @}
1559
1560    /// \name Using previously constructed node or edge set
1561    /// @{
1562
1563    /// \brief Use previously constructed node set
1564    ///
1565    /// Use previously constructed node set, and specify the node
1566    /// label map.
1567    template <typename Map>
1568    GraphReader& useNodes(const Map& map) {
1569      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1570      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1571      _use_nodes = true;
1572      _writer_bits::DefaultConverter<typename Map::Value> converter;
1573      for (NodeIt n(_graph); n != INVALID; ++n) {
1574        _node_index.insert(std::make_pair(converter(map[n]), n));
1575      }
1576      return *this;
1577    }
1578
1579    /// \brief Use previously constructed node set
1580    ///
1581    /// Use previously constructed node set, and specify the node
1582    /// label map and a functor which converts the label map values to
1583    /// \c std::string.
1584    template <typename Map, typename Converter>
1585    GraphReader& useNodes(const Map& map,
1586                            const Converter& converter = Converter()) {
1587      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1588      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1589      _use_nodes = true;
1590      for (NodeIt n(_graph); n != INVALID; ++n) {
1591        _node_index.insert(std::make_pair(converter(map[n]), n));
1592      }
1593      return *this;
1594    }
1595
1596    /// \brief Use previously constructed edge set
1597    ///
1598    /// Use previously constructed edge set, and specify the edge
1599    /// label map.
1600    template <typename Map>
1601    GraphReader& useEdges(const Map& map) {
1602      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1603      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1604      _use_edges = true;
1605      _writer_bits::DefaultConverter<typename Map::Value> converter;
1606      for (EdgeIt a(_graph); a != INVALID; ++a) {
1607        _edge_index.insert(std::make_pair(converter(map[a]), a));
1608      }
1609      return *this;
1610    }
1611
1612    /// \brief Use previously constructed edge set
1613    ///
1614    /// Use previously constructed edge set, and specify the edge
1615    /// label map and a functor which converts the label map values to
1616    /// \c std::string.
1617    template <typename Map, typename Converter>
1618    GraphReader& useEdges(const Map& map,
1619                            const Converter& converter = Converter()) {
1620      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1621      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1622      _use_edges = true;
1623      for (EdgeIt a(_graph); a != INVALID; ++a) {
1624        _edge_index.insert(std::make_pair(converter(map[a]), a));
1625      }
1626      return *this;
1627    }
1628
1629    /// \brief Skip the reading of node section
1630    ///
1631    /// Omit the reading of the node section. This implies that each node
1632    /// map reading rule will be abandoned, and the nodes of the graph
1633    /// will not be constructed, which usually cause that the edge set
1634    /// could not be read due to lack of node name
1635    /// could not be read due to lack of node name resolving.
1636    /// Therefore \c skipEdges() function should also be used, or
1637    /// \c useNodes() should be used to specify the label of the nodes.
1638    GraphReader& skipNodes() {
1639      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
1640      _skip_nodes = true;
1641      return *this;
1642    }
1643
1644    /// \brief Skip the reading of edge section
1645    ///
1646    /// Omit the reading of the edge section. This implies that each edge
1647    /// map reading rule will be abandoned, and the edges of the graph
1648    /// will not be constructed.
1649    GraphReader& skipEdges() {
1650      LEMON_ASSERT(!_skip_edges, "Skip edges already set");
1651      _skip_edges = true;
1652      return *this;
1653    }
1654
1655    /// @}
1656
1657  private:
1658
1659    bool readLine() {
1660      std::string str;
1661      while(++line_num, std::getline(*_is, str)) {
1662        line.clear(); line.str(str);
1663        char c;
1664        if (line >> std::ws >> c && c != '#') {
1665          line.putback(c);
1666          return true;
1667        }
1668      }
1669      return false;
1670    }
1671
1672    bool readSuccess() {
1673      return static_cast<bool>(*_is);
1674    }
1675
1676    void skipSection() {
1677      char c;
1678      while (readSuccess() && line >> c && c != '@') {
1679        readLine();
1680      }
1681      line.putback(c);
1682    }
1683
1684    void readNodes() {
1685
1686      std::vector<int> map_index(_node_maps.size());
1687      int map_num, label_index;
1688
1689      char c;
1690      if (!readLine() || !(line >> c) || c == '@') {
1691        if (readSuccess() && line) line.putback(c);
1692        if (!_node_maps.empty())
1693          throw FormatError("Cannot find map names");
1694        return;
1695      }
1696      line.putback(c);
1697
1698      {
1699        std::map<std::string, int> maps;
1700
1701        std::string map;
1702        int index = 0;
1703        while (_reader_bits::readToken(line, map)) {
1704          if (maps.find(map) != maps.end()) {
1705            std::ostringstream msg;
1706            msg << "Multiple occurence of node map: " << map;
1707            throw FormatError(msg.str());
1708          }
1709          maps.insert(std::make_pair(map, index));
1710          ++index;
1711        }
1712
1713        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1714          std::map<std::string, int>::iterator jt =
1715            maps.find(_node_maps[i].first);
1716          if (jt == maps.end()) {
1717            std::ostringstream msg;
1718            msg << "Map not found: " << _node_maps[i].first;
1719            throw FormatError(msg.str());
1720          }
1721          map_index[i] = jt->second;
1722        }
1723
1724        {
1725          std::map<std::string, int>::iterator jt = maps.find("label");
1726          if (jt != maps.end()) {
1727            label_index = jt->second;
1728          } else {
1729            label_index = -1;
1730          }
1731        }
1732        map_num = maps.size();
1733      }
1734
1735      while (readLine() && line >> c && c != '@') {
1736        line.putback(c);
1737
1738        std::vector<std::string> tokens(map_num);
1739        for (int i = 0; i < map_num; ++i) {
1740          if (!_reader_bits::readToken(line, tokens[i])) {
1741            std::ostringstream msg;
1742            msg << "Column not found (" << i + 1 << ")";
1743            throw FormatError(msg.str());
1744          }
1745        }
1746        if (line >> std::ws >> c)
1747          throw FormatError("Extra character at the end of line");
1748
1749        Node n;
1750        if (!_use_nodes) {
1751          n = _graph.addNode();
1752          if (label_index != -1)
1753            _node_index.insert(std::make_pair(tokens[label_index], n));
1754        } else {
1755          if (label_index == -1)
1756            throw FormatError("Label map not found");
1757          typename std::map<std::string, Node>::iterator it =
1758            _node_index.find(tokens[label_index]);
1759          if (it == _node_index.end()) {
1760            std::ostringstream msg;
1761            msg << "Node with label not found: " << tokens[label_index];
1762            throw FormatError(msg.str());
1763          }
1764          n = it->second;
1765        }
1766
1767        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1768          _node_maps[i].second->set(n, tokens[map_index[i]]);
1769        }
1770
1771      }
1772      if (readSuccess()) {
1773        line.putback(c);
1774      }
1775    }
1776
1777    void readEdges() {
1778
1779      std::vector<int> map_index(_edge_maps.size());
1780      int map_num, label_index;
1781
1782      char c;
1783      if (!readLine() || !(line >> c) || c == '@') {
1784        if (readSuccess() && line) line.putback(c);
1785        if (!_edge_maps.empty())
1786          throw FormatError("Cannot find map names");
1787        return;
1788      }
1789      line.putback(c);
1790
1791      {
1792        std::map<std::string, int> maps;
1793
1794        std::string map;
1795        int index = 0;
1796        while (_reader_bits::readToken(line, map)) {
1797          if (maps.find(map) != maps.end()) {
1798            std::ostringstream msg;
1799            msg << "Multiple occurence of edge map: " << map;
1800            throw FormatError(msg.str());
1801          }
1802          maps.insert(std::make_pair(map, index));
1803          ++index;
1804        }
1805
1806        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1807          std::map<std::string, int>::iterator jt =
1808            maps.find(_edge_maps[i].first);
1809          if (jt == maps.end()) {
1810            std::ostringstream msg;
1811            msg << "Map not found: " << _edge_maps[i].first;
1812            throw FormatError(msg.str());
1813          }
1814          map_index[i] = jt->second;
1815        }
1816
1817        {
1818          std::map<std::string, int>::iterator jt = maps.find("label");
1819          if (jt != maps.end()) {
1820            label_index = jt->second;
1821          } else {
1822            label_index = -1;
1823          }
1824        }
1825        map_num = maps.size();
1826      }
1827
1828      while (readLine() && line >> c && c != '@') {
1829        line.putback(c);
1830
1831        std::string source_token;
1832        std::string target_token;
1833
1834        if (!_reader_bits::readToken(line, source_token))
1835          throw FormatError("Node u not found");
1836
1837        if (!_reader_bits::readToken(line, target_token))
1838          throw FormatError("Node v not found");
1839
1840        std::vector<std::string> tokens(map_num);
1841        for (int i = 0; i < map_num; ++i) {
1842          if (!_reader_bits::readToken(line, tokens[i])) {
1843            std::ostringstream msg;
1844            msg << "Column not found (" << i + 1 << ")";
1845            throw FormatError(msg.str());
1846          }
1847        }
1848        if (line >> std::ws >> c)
1849          throw FormatError("Extra character at the end of line");
1850
1851        Edge e;
1852        if (!_use_edges) {
1853
1854          typename NodeIndex::iterator it;
1855
1856          it = _node_index.find(source_token);
1857          if (it == _node_index.end()) {
1858            std::ostringstream msg;
1859            msg << "Item not found: " << source_token;
1860            throw FormatError(msg.str());
1861          }
1862          Node source = it->second;
1863
1864          it = _node_index.find(target_token);
1865          if (it == _node_index.end()) {
1866            std::ostringstream msg;
1867            msg << "Item not found: " << target_token;
1868            throw FormatError(msg.str());
1869          }
1870          Node target = it->second;
1871
1872          e = _graph.addEdge(source, target);
1873          if (label_index != -1)
1874            _edge_index.insert(std::make_pair(tokens[label_index], e));
1875        } else {
1876          if (label_index == -1)
1877            throw FormatError("Label map not found");
1878          typename std::map<std::string, Edge>::iterator it =
1879            _edge_index.find(tokens[label_index]);
1880          if (it == _edge_index.end()) {
1881            std::ostringstream msg;
1882            msg << "Edge with label not found: " << tokens[label_index];
1883            throw FormatError(msg.str());
1884          }
1885          e = it->second;
1886        }
1887
1888        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1889          _edge_maps[i].second->set(e, tokens[map_index[i]]);
1890        }
1891
1892      }
1893      if (readSuccess()) {
1894        line.putback(c);
1895      }
1896    }
1897
1898    void readAttributes() {
1899
1900      std::set<std::string> read_attr;
1901
1902      char c;
1903      while (readLine() && line >> c && c != '@') {
1904        line.putback(c);
1905
1906        std::string attr, token;
1907        if (!_reader_bits::readToken(line, attr))
1908          throw FormatError("Attribute name not found");
1909        if (!_reader_bits::readToken(line, token))
1910          throw FormatError("Attribute value not found");
1911        if (line >> c)
1912          throw FormatError("Extra character at the end of line");
1913
1914        {
1915          std::set<std::string>::iterator it = read_attr.find(attr);
1916          if (it != read_attr.end()) {
1917            std::ostringstream msg;
1918            msg << "Multiple occurence of attribute: " << attr;
1919            throw FormatError(msg.str());
1920          }
1921          read_attr.insert(attr);
1922        }
1923
1924        {
1925          typename Attributes::iterator it = _attributes.lower_bound(attr);
1926          while (it != _attributes.end() && it->first == attr) {
1927            it->second->set(token);
1928            ++it;
1929          }
1930        }
1931
1932      }
1933      if (readSuccess()) {
1934        line.putback(c);
1935      }
1936      for (typename Attributes::iterator it = _attributes.begin();
1937           it != _attributes.end(); ++it) {
1938        if (read_attr.find(it->first) == read_attr.end()) {
1939          std::ostringstream msg;
1940          msg << "Attribute not found: " << it->first;
1941          throw FormatError(msg.str());
1942        }
1943      }
1944    }
1945
1946  public:
1947
1948    /// \name Execution of the reader
1949    /// @{
1950
1951    /// \brief Start the batch processing
1952    ///
1953    /// This function starts the batch processing
1954    void run() {
1955
1956      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1957
1958      bool nodes_done = _skip_nodes;
1959      bool edges_done = _skip_edges;
1960      bool attributes_done = false;
1961
1962      line_num = 0;
1963      readLine();
1964      skipSection();
1965
1966      while (readSuccess()) {
1967        try {
1968          char c;
1969          std::string section, caption;
1970          line >> c;
1971          _reader_bits::readToken(line, section);
1972          _reader_bits::readToken(line, caption);
1973
1974          if (line >> c)
1975            throw FormatError("Extra character at the end of line");
1976
1977          if (section == "nodes" && !nodes_done) {
1978            if (_nodes_caption.empty() || _nodes_caption == caption) {
1979              readNodes();
1980              nodes_done = true;
1981            }
1982          } else if ((section == "edges" || section == "arcs") &&
1983                     !edges_done) {
1984            if (_edges_caption.empty() || _edges_caption == caption) {
1985              readEdges();
1986              edges_done = true;
1987            }
1988          } else if (section == "attributes" && !attributes_done) {
1989            if (_attributes_caption.empty() || _attributes_caption == caption) {
1990              readAttributes();
1991              attributes_done = true;
1992            }
1993          } else {
1994            readLine();
1995            skipSection();
1996          }
1997        } catch (FormatError& error) {
1998          error.line(line_num);
1999          error.file(_filename);
2000          throw;
2001        }
2002      }
2003
2004      if (!nodes_done) {
2005        throw FormatError("Section @nodes not found");
2006      }
2007
2008      if (!edges_done) {
2009        throw FormatError("Section @edges not found");
2010      }
2011
2012      if (!attributes_done && !_attributes.empty()) {
2013        throw FormatError("Section @attributes not found");
2014      }
2015
2016    }
2017
2018    /// @}
2019
2020  };
2021
2022  /// \brief Return a \ref GraphReader class
2023  ///
2024  /// This function just returns a \ref GraphReader class.
2025  /// \relates GraphReader
2026  template <typename Graph>
2027  GraphReader<Graph> graphReader(Graph& graph, std::istream& is = std::cin) {
2028    GraphReader<Graph> tmp(graph, is);
2029    return tmp;
2030  }
2031
2032  /// \brief Return a \ref GraphReader class
2033  ///
2034  /// This function just returns a \ref GraphReader class.
2035  /// \relates GraphReader
2036  template <typename Graph>
2037  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {
2038    GraphReader<Graph> tmp(graph, fn);
2039    return tmp;
2040  }
2041
2042  /// \brief Return a \ref GraphReader class
2043  ///
2044  /// This function just returns a \ref GraphReader class.
2045  /// \relates GraphReader
2046  template <typename Graph>
2047  GraphReader<Graph> graphReader(Graph& graph, const char* fn) {
2048    GraphReader<Graph> tmp(graph, fn);
2049    return tmp;
2050  }
2051
2052  class SectionReader;
2053
2054  SectionReader sectionReader(std::istream& is);
2055  SectionReader sectionReader(const std::string& fn);
2056  SectionReader sectionReader(const char* fn);
2057
2058  /// \ingroup lemon_io
2059  ///
2060  /// \brief Section reader class
2061  ///
2062  /// In the \ref lgf-format "LGF" file extra sections can be placed,
2063  /// which contain any data in arbitrary format. Such sections can be
2064  /// read with this class. A reading rule can be added to the class
2065  /// with two different functions. With the \c sectionLines() function a
2066  /// functor can process the section line-by-line, while with the \c
2067  /// sectionStream() member the section can be read from an input
2068  /// stream.
2069  class SectionReader {
2070  private:
2071
2072    std::istream* _is;
2073    bool local_is;
2074    std::string _filename;
2075
2076    typedef std::map<std::string, _reader_bits::Section*> Sections;
2077    Sections _sections;
2078
2079    int line_num;
2080    std::istringstream line;
2081
2082  public:
2083
2084    /// \brief Constructor
2085    ///
2086    /// Construct a section reader, which reads from the given input
2087    /// stream.
2088    SectionReader(std::istream& is)
2089      : _is(&is), local_is(false) {}
2090
2091    /// \brief Constructor
2092    ///
2093    /// Construct a section reader, which reads from the given file.
2094    SectionReader(const std::string& fn)
2095      : _is(new std::ifstream(fn.c_str())), local_is(true),
2096        _filename(fn) {
2097      if (!(*_is)) throw IoError("Cannot open file", fn);
2098    }
2099
2100    /// \brief Constructor
2101    ///
2102    /// Construct a section reader, which reads from the given file.
2103    SectionReader(const char* fn)
2104      : _is(new std::ifstream(fn)), local_is(true),
2105        _filename(fn) {
2106      if (!(*_is)) throw IoError("Cannot open file", fn);
2107    }
2108
2109    /// \brief Destructor
2110    ~SectionReader() {
2111      for (Sections::iterator it = _sections.begin();
2112           it != _sections.end(); ++it) {
2113        delete it->second;
2114      }
2115
2116      if (local_is) {
2117        delete _is;
2118      }
2119
2120    }
2121
2122  private:
2123
2124    friend SectionReader sectionReader(std::istream& is);
2125    friend SectionReader sectionReader(const std::string& fn);
2126    friend SectionReader sectionReader(const char* fn);
2127
2128    SectionReader(SectionReader& other)
2129      : _is(other._is), local_is(other.local_is) {
2130
2131      other._is = 0;
2132      other.local_is = false;
2133
2134      _sections.swap(other._sections);
2135    }
2136
2137    SectionReader& operator=(const SectionReader&);
2138
2139  public:
2140
2141    /// \name Section readers
2142    /// @{
2143
2144    /// \brief Add a section processor with line oriented reading
2145    ///
2146    /// The first parameter is the type descriptor of the section, the
2147    /// second is a functor, which takes just one \c std::string
2148    /// parameter. At the reading process, each line of the section
2149    /// will be given to the functor object. However, the empty lines
2150    /// and the comment lines are filtered out, and the leading
2151    /// whitespaces are trimmed from each processed string.
2152    ///
2153    /// For example let's see a section, which contain several
2154    /// integers, which should be inserted into a vector.
2155    ///\code
2156    ///  @numbers
2157    ///  12 45 23
2158    ///  4
2159    ///  23 6
2160    ///\endcode
2161    ///
2162    /// The functor is implemented as a struct:
2163    ///\code
2164    ///  struct NumberSection {
2165    ///    std::vector<int>& _data;
2166    ///    NumberSection(std::vector<int>& data) : _data(data) {}
2167    ///    void operator()(const std::string& line) {
2168    ///      std::istringstream ls(line);
2169    ///      int value;
2170    ///      while (ls >> value) _data.push_back(value);
2171    ///    }
2172    ///  };
2173    ///
2174    ///  // ...
2175    ///
2176    ///  reader.sectionLines("numbers", NumberSection(vec));
2177    ///\endcode
2178    template <typename Functor>
2179    SectionReader& sectionLines(const std::string& type, Functor functor) {
2180      LEMON_ASSERT(!type.empty(), "Type is empty.");
2181      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2182                   "Multiple reading of section.");
2183      _sections.insert(std::make_pair(type,
2184        new _reader_bits::LineSection<Functor>(functor)));
2185      return *this;
2186    }
2187
2188
2189    /// \brief Add a section processor with stream oriented reading
2190    ///
2191    /// The first parameter is the type of the section, the second is
2192    /// a functor, which takes an \c std::istream& and an \c int&
2193    /// parameter, the latter regard to the line number of stream. The
2194    /// functor can read the input while the section go on, and the
2195    /// line number should be modified accordingly.
2196    template <typename Functor>
2197    SectionReader& sectionStream(const std::string& type, Functor functor) {
2198      LEMON_ASSERT(!type.empty(), "Type is empty.");
2199      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2200                   "Multiple reading of section.");
2201      _sections.insert(std::make_pair(type,
2202         new _reader_bits::StreamSection<Functor>(functor)));
2203      return *this;
2204    }
2205
2206    /// @}
2207
2208  private:
2209
2210    bool readLine() {
2211      std::string str;
2212      while(++line_num, std::getline(*_is, str)) {
2213        line.clear(); line.str(str);
2214        char c;
2215        if (line >> std::ws >> c && c != '#') {
2216          line.putback(c);
2217          return true;
2218        }
2219      }
2220      return false;
2221    }
2222
2223    bool readSuccess() {
2224      return static_cast<bool>(*_is);
2225    }
2226
2227    void skipSection() {
2228      char c;
2229      while (readSuccess() && line >> c && c != '@') {
2230        readLine();
2231      }
2232      line.putback(c);
2233    }
2234
2235  public:
2236
2237
2238    /// \name Execution of the reader
2239    /// @{
2240
2241    /// \brief Start the batch processing
2242    ///
2243    /// This function starts the batch processing.
2244    void run() {
2245
2246      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
2247
2248      std::set<std::string> extra_sections;
2249
2250      line_num = 0;
2251      readLine();
2252      skipSection();
2253
2254      while (readSuccess()) {
2255        try {
2256          char c;
2257          std::string section, caption;
2258          line >> c;
2259          _reader_bits::readToken(line, section);
2260          _reader_bits::readToken(line, caption);
2261
2262          if (line >> c)
2263            throw FormatError("Extra character at the end of line");
2264
2265          if (extra_sections.find(section) != extra_sections.end()) {
2266            std::ostringstream msg;
2267            msg << "Multiple occurence of section: " << section;
2268            throw FormatError(msg.str());
2269          }
2270          Sections::iterator it = _sections.find(section);
2271          if (it != _sections.end()) {
2272            extra_sections.insert(section);
2273            it->second->process(*_is, line_num);
2274          }
2275          readLine();
2276          skipSection();
2277        } catch (FormatError& error) {
2278          error.line(line_num);
2279          error.file(_filename);
2280          throw;
2281        }
2282      }
2283      for (Sections::iterator it = _sections.begin();
2284           it != _sections.end(); ++it) {
2285        if (extra_sections.find(it->first) == extra_sections.end()) {
2286          std::ostringstream os;
2287          os << "Cannot find section: " << it->first;
2288          throw FormatError(os.str());
2289        }
2290      }
2291    }
2292
2293    /// @}
2294
2295  };
2296
2297  /// \brief Return a \ref SectionReader class
2298  ///
2299  /// This function just returns a \ref SectionReader class.
2300  /// \relates SectionReader
2301  inline SectionReader sectionReader(std::istream& is) {
2302    SectionReader tmp(is);
2303    return tmp;
2304  }
2305
2306  /// \brief Return a \ref SectionReader class
2307  ///
2308  /// This function just returns a \ref SectionReader class.
2309  /// \relates SectionReader
2310  inline SectionReader sectionReader(const std::string& fn) {
2311    SectionReader tmp(fn);
2312    return tmp;
2313  }
2314
2315  /// \brief Return a \ref SectionReader class
2316  ///
2317  /// This function just returns a \ref SectionReader class.
2318  /// \relates SectionReader
2319  inline SectionReader sectionReader(const char* fn) {
2320    SectionReader tmp(fn);
2321    return tmp;
2322  }
2323
2324  /// \ingroup lemon_io
2325  ///
2326  /// \brief Reader for the contents of the \ref lgf-format "LGF" file
2327  ///
2328  /// This class can be used to read the sections, the map names and
2329  /// the attributes from a file. Usually, the LEMON programs know
2330  /// that, which type of graph, which maps and which attributes
2331  /// should be read from a file, but in general tools (like glemon)
2332  /// the contents of an LGF file should be guessed somehow. This class
2333  /// reads the graph and stores the appropriate information for
2334  /// reading the graph.
2335  ///
2336  ///\code
2337  /// LgfContents contents("graph.lgf");
2338  /// contents.run();
2339  ///
2340  /// // Does it contain any node section and arc section?
2341  /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
2342  ///   std::cerr << "Failure, cannot find graph." << std::endl;
2343  ///   return -1;
2344  /// }
2345  /// std::cout << "The name of the default node section: "
2346  ///           << contents.nodeSection(0) << std::endl;
2347  /// std::cout << "The number of the arc maps: "
2348  ///           << contents.arcMaps(0).size() << std::endl;
2349  /// std::cout << "The name of second arc map: "
2350  ///           << contents.arcMaps(0)[1] << std::endl;
2351  ///\endcode
2352  class LgfContents {
2353  private:
2354
2355    std::istream* _is;
2356    bool local_is;
2357
2358    std::vector<std::string> _node_sections;
2359    std::vector<std::string> _edge_sections;
2360    std::vector<std::string> _attribute_sections;
2361    std::vector<std::string> _extra_sections;
2362
2363    std::vector<bool> _arc_sections;
2364
2365    std::vector<std::vector<std::string> > _node_maps;
2366    std::vector<std::vector<std::string> > _edge_maps;
2367
2368    std::vector<std::vector<std::string> > _attributes;
2369
2370
2371    int line_num;
2372    std::istringstream line;
2373
2374  public:
2375
2376    /// \brief Constructor
2377    ///
2378    /// Construct an \e LGF contents reader, which reads from the given
2379    /// input stream.
2380    LgfContents(std::istream& is)
2381      : _is(&is), local_is(false) {}
2382
2383    /// \brief Constructor
2384    ///
2385    /// Construct an \e LGF contents reader, which reads from the given
2386    /// file.
2387    LgfContents(const std::string& fn)
2388      : _is(new std::ifstream(fn.c_str())), local_is(true) {
2389      if (!(*_is)) throw IoError("Cannot open file", fn);
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)) throw IoError("Cannot open file", fn);
2399    }
2400
2401    /// \brief Destructor
2402    ~LgfContents() {
2403      if (local_is) delete _is;
2404    }
2405
2406  private:
2407
2408    LgfContents(const LgfContents&);
2409    LgfContents& operator=(const LgfContents&);
2410
2411  public:
2412
2413
2414    /// \name Node sections
2415    /// @{
2416
2417    /// \brief Gives back the number of node sections in the file.
2418    ///
2419    /// Gives back the number of node sections in the file.
2420    int nodeSectionNum() const {
2421      return _node_sections.size();
2422    }
2423
2424    /// \brief Returns the node section name at the given position.
2425    ///
2426    /// Returns the node section name at the given position.
2427    const std::string& nodeSection(int i) const {
2428      return _node_sections[i];
2429    }
2430
2431    /// \brief Gives back the node maps for the given section.
2432    ///
2433    /// Gives back the node maps for the given section.
2434    const std::vector<std::string>& nodeMapNames(int i) const {
2435      return _node_maps[i];
2436    }
2437
2438    /// @}
2439
2440    /// \name Arc/Edge sections
2441    /// @{
2442
2443    /// \brief Gives back the number of arc/edge sections in the file.
2444    ///
2445    /// Gives back the number of arc/edge sections in the file.
2446    /// \note It is synonym of \c edgeSectionNum().
2447    int arcSectionNum() const {
2448      return _edge_sections.size();
2449    }
2450
2451    /// \brief Returns the arc/edge section name at the given position.
2452    ///
2453    /// Returns the arc/edge section name at the given position.
2454    /// \note It is synonym of \c edgeSection().
2455    const std::string& arcSection(int i) const {
2456      return _edge_sections[i];
2457    }
2458
2459    /// \brief Gives back the arc/edge maps for the given section.
2460    ///
2461    /// Gives back the arc/edge maps for the given section.
2462    /// \note It is synonym of \c edgeMapNames().
2463    const std::vector<std::string>& arcMapNames(int i) const {
2464      return _edge_maps[i];
2465    }
2466
2467    /// @}
2468
2469    /// \name Synonyms
2470    /// @{
2471
2472    /// \brief Gives back the number of arc/edge sections in the file.
2473    ///
2474    /// Gives back the number of arc/edge sections in the file.
2475    /// \note It is synonym of \c arcSectionNum().
2476    int edgeSectionNum() const {
2477      return _edge_sections.size();
2478    }
2479
2480    /// \brief Returns the section name at the given position.
2481    ///
2482    /// Returns the section name at the given position.
2483    /// \note It is synonym of \c arcSection().
2484    const std::string& edgeSection(int i) const {
2485      return _edge_sections[i];
2486    }
2487
2488    /// \brief Gives back the edge maps for the given section.
2489    ///
2490    /// Gives back the edge maps for the given section.
2491    /// \note It is synonym of \c arcMapNames().
2492    const std::vector<std::string>& edgeMapNames(int i) const {
2493      return _edge_maps[i];
2494    }
2495
2496    /// @}
2497
2498    /// \name Attribute sections
2499    /// @{
2500
2501    /// \brief Gives back the number of attribute sections in the file.
2502    ///
2503    /// Gives back the number of attribute sections in the file.
2504    int attributeSectionNum() const {
2505      return _attribute_sections.size();
2506    }
2507
2508    /// \brief Returns the attribute section name at the given position.
2509    ///
2510    /// Returns the attribute section name at the given position.
2511    const std::string& attributeSectionNames(int i) const {
2512      return _attribute_sections[i];
2513    }
2514
2515    /// \brief Gives back the attributes for the given section.
2516    ///
2517    /// Gives back the attributes for the given section.
2518    const std::vector<std::string>& attributes(int i) const {
2519      return _attributes[i];
2520    }
2521
2522    /// @}
2523
2524    /// \name Extra sections
2525    /// @{
2526
2527    /// \brief Gives back the number of extra sections in the file.
2528    ///
2529    /// Gives back the number of extra sections in the file.
2530    int extraSectionNum() const {
2531      return _extra_sections.size();
2532    }
2533
2534    /// \brief Returns the extra section type at the given position.
2535    ///
2536    /// Returns the section type at the given position.
2537    const std::string& extraSection(int i) const {
2538      return _extra_sections[i];
2539    }
2540
2541    /// @}
2542
2543  private:
2544
2545    bool readLine() {
2546      std::string str;
2547      while(++line_num, std::getline(*_is, str)) {
2548        line.clear(); line.str(str);
2549        char c;
2550        if (line >> std::ws >> c && c != '#') {
2551          line.putback(c);
2552          return true;
2553        }
2554      }
2555      return false;
2556    }
2557
2558    bool readSuccess() {
2559      return static_cast<bool>(*_is);
2560    }
2561
2562    void skipSection() {
2563      char c;
2564      while (readSuccess() && line >> c && c != '@') {
2565        readLine();
2566      }
2567      line.putback(c);
2568    }
2569
2570    void readMaps(std::vector<std::string>& maps) {
2571      char c;
2572      if (!readLine() || !(line >> c) || c == '@') {
2573        if (readSuccess() && line) line.putback(c);
2574        return;
2575      }
2576      line.putback(c);
2577      std::string map;
2578      while (_reader_bits::readToken(line, map)) {
2579        maps.push_back(map);
2580      }
2581    }
2582
2583    void readAttributes(std::vector<std::string>& attrs) {
2584      readLine();
2585      char c;
2586      while (readSuccess() && line >> c && c != '@') {
2587        line.putback(c);
2588        std::string attr;
2589        _reader_bits::readToken(line, attr);
2590        attrs.push_back(attr);
2591        readLine();
2592      }
2593      line.putback(c);
2594    }
2595
2596  public:
2597
2598    /// \name Execution of the contents reader
2599    /// @{
2600
2601    /// \brief Starts the reading
2602    ///
2603    /// This function starts the reading.
2604    void run() {
2605
2606      readLine();
2607      skipSection();
2608
2609      while (readSuccess()) {
2610
2611        char c;
2612        line >> c;
2613
2614        std::string section, caption;
2615        _reader_bits::readToken(line, section);
2616        _reader_bits::readToken(line, caption);
2617
2618        if (section == "nodes") {
2619          _node_sections.push_back(caption);
2620          _node_maps.push_back(std::vector<std::string>());
2621          readMaps(_node_maps.back());
2622          readLine(); skipSection();
2623        } else if (section == "arcs" || section == "edges") {
2624          _edge_sections.push_back(caption);
2625          _arc_sections.push_back(section == "arcs");
2626          _edge_maps.push_back(std::vector<std::string>());
2627          readMaps(_edge_maps.back());
2628          readLine(); skipSection();
2629        } else if (section == "attributes") {
2630          _attribute_sections.push_back(caption);
2631          _attributes.push_back(std::vector<std::string>());
2632          readAttributes(_attributes.back());
2633        } else {
2634          _extra_sections.push_back(section);
2635          readLine(); skipSection();
2636        }
2637      }
2638    }
2639
2640    /// @}
2641
2642  };
2643}
2644
2645#endif
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