read_graphviz_new.cpp 31.3 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
// Copyright 2004-9 Trustees of Indiana University

// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

//
// read_graphviz_new.cpp - 
//   Initialize a model of the BGL's MutableGraph concept and an associated
//  collection of property maps using a graph expressed in the GraphViz
// DOT Language.  
//
//   Based on the grammar found at:
//   http://www.graphviz.org/cvs/doc/info/lang.html
//
//   Jeremiah rewrite used grammar found at:
//   http://www.graphviz.org/doc/info/lang.html
//   and page 34 or http://www.graphviz.org/pdf/dotguide.pdf
//
//   See documentation for this code at: 
//     http://www.boost.org/libs/graph/doc/read-graphviz.html
//

// Author: Jeremiah Willcock
//         Ronald Garcia
//

#include <boost/ref.hpp>
#include <boost/function/function2.hpp>
#include <boost/dynamic_property_map.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/algorithm/string/case_conv.hpp>
#include <algorithm>
#include <exception> // for std::exception
#include <string>
#include <vector>
#include <set>
#include <utility>
#include <map>
#include <iostream>
#include <cstdlib>
#include <boost/throw_exception.hpp>
#include <boost/regex.hpp>
#include <boost/function.hpp>
#include <boost/bind.hpp>
#include <boost/graph/graphviz.hpp>

namespace boost {

namespace read_graphviz_detail {
  struct token {
    enum token_type {
      kw_strict,
      kw_graph,
      kw_digraph,
      kw_node,
      kw_edge,
      kw_subgraph,
      left_brace,
      right_brace,
      semicolon,
      equal,
      left_bracket,
      right_bracket,
      comma,
      colon,
      dash_greater,
      dash_dash,
      plus,
      left_paren,
      right_paren,
      at,
      identifier,
      quoted_string, // Only used internally in tokenizer
      eof,
      invalid
    } type;
    std::string normalized_value; // May have double-quotes removed and/or some escapes replaced
    token(token_type type, const std::string& normalized_value)
      : type(type), normalized_value(normalized_value) {}
    token(): type(invalid), normalized_value("") {}
    friend std::ostream& operator<<(std::ostream& o, const token& t) {
      switch (t.type) {
        case token::kw_strict: o << "<strict>"; break;
        case token::kw_graph: o << "<graph>"; break;
        case token::kw_digraph: o << "<digraph>"; break;
        case token::kw_node: o << "<node>"; break;
        case token::kw_edge: o << "<edge>"; break;
        case token::kw_subgraph: o << "<subgraph>"; break;
        case token::left_brace: o << "<left_brace>"; break;
        case token::right_brace: o << "<right_brace>"; break;
        case token::semicolon: o << "<semicolon>"; break;
        case token::equal: o << "<equal>"; break;
        case token::left_bracket: o << "<left_bracket>"; break;
        case token::right_bracket: o << "<right_bracket>"; break;
        case token::comma: o << "<comma>"; break;
        case token::colon: o << "<colon>"; break;
        case token::dash_greater: o << "<dash-greater>"; break;
        case token::dash_dash: o << "<dash-dash>"; break;
        case token::plus: o << "<plus>"; break;
        case token::left_paren: o << "<left_paren>"; break;
        case token::right_paren: o << "<right_paren>"; break;
        case token::at: o << "<at>"; break;
        case token::identifier: o << "<identifier>"; break;
        case token::quoted_string: o << "<quoted_string>"; break;
        case token::eof: o << "<eof>"; break;
        default: o << "<invalid type>"; break;
      }
      o << " '" << t.normalized_value << "'";
      return o;
    }
  };

  bad_graphviz_syntax lex_error(const std::string& errmsg, char bad_char) {
    if (bad_char == '\0') {
      return bad_graphviz_syntax(errmsg + " (at end of input)");
    } else {
      return bad_graphviz_syntax(errmsg + " (char is '" + bad_char + "')");
    }
  }

  bad_graphviz_syntax parse_error(const std::string& errmsg, const token& bad_token) {
    return bad_graphviz_syntax(errmsg + " (token is \"" + boost::lexical_cast<std::string>(bad_token) + "\")");
  }

  struct tokenizer {
    std::string::const_iterator begin, end;
    std::vector<token> lookahead;
    // Precomputed regexes
    boost::regex stuff_to_skip;
    boost::regex basic_id_token;
    boost::regex punctuation_token;
    boost::regex number_token;
    boost::regex quoted_string_token;
    boost::regex xml_tag_token;
    boost::regex cdata;

    tokenizer(const std::string& str) : begin(str.begin()), end(str.end())
    {
      std::string end_of_token = "(?=(?:\\W))";
      std::string whitespace = "(?:\\s+)";
      std::string slash_slash_comment = "(?://.*$)";
      std::string slash_star_comment = "(?:/\\*.*?\\*/)";
      std::string hash_comment = "(?:^#.*?$)";
      std::string backslash_newline = "(?:[\\\\][\\n])";
      stuff_to_skip = "\\A(?:" + whitespace + "|" +
                                 slash_slash_comment + "|" +
                                 slash_star_comment + "|" +
                                 hash_comment + "|" +
                                 backslash_newline + ")*";
      basic_id_token = "\\A([[:alpha:]_](?:\\w*))";
      punctuation_token = "\\A([][{};=,:+()@]|[-][>-])";
      number_token = "\\A([-]?(?:(?:\\.\\d+)|(?:\\d+(?:\\.\\d*)?)))";
      quoted_string_token = "\\A(\"(?:[^\"\\\\]|(?:[\\\\].))*\")";
      xml_tag_token = "\\A<(/?)(?:[^!?'\"]|(?:'[^']*?')|(?:\"[^\"]*?\"))*?(/?)>";
      cdata = "\\A\\Q<![CDATA[\\E.*?\\Q]]>\\E";
    }

    void skip() {
      boost::match_results<std::string::const_iterator> results;
#ifndef NDEBUG
      bool found =
#endif
        boost::regex_search(begin, end, results, stuff_to_skip);
#ifndef NDEBUG
      assert (found);
#endif
      boost::sub_match<std::string::const_iterator> sm1 = results.suffix();
      assert (sm1.second == end);
      begin = sm1.first;
    }

    token get_token_raw() {
      if (!lookahead.empty()) {
        token t = lookahead.front();
        lookahead.erase(lookahead.begin());
        return t;
      }
      skip();
      if (begin == end) return token(token::eof, "");
      // Look for keywords first
      bool found;
      boost::match_results<std::string::const_iterator> results;
      found = boost::regex_search(begin, end, results, basic_id_token);
      if (found) {
        std::string str = results[1].str();
        std::string str_lower = boost::algorithm::to_lower_copy(str);
        begin = results.suffix().first;
        if (str_lower == "strict") {
          return token(token::kw_strict, str);
        } else if (str_lower == "graph") {
          return token(token::kw_graph, str);
        } else if (str_lower == "digraph") {
          return token(token::kw_digraph, str);
        } else if (str_lower == "node") {
          return token(token::kw_node, str);
        } else if (str_lower == "edge") {
          return token(token::kw_edge, str);
        } else if (str_lower == "subgraph") {
          return token(token::kw_subgraph, str);
        } else {
          return token(token::identifier, str);
        }
      }
      found = boost::regex_search(begin, end, results, punctuation_token);
      if (found) {
        std::string str = results[1].str();
        begin = results.suffix().first;
        switch (str[0]) {
          case '[': return token(token::left_bracket, str);
          case ']': return token(token::right_bracket, str);
          case '{': return token(token::left_brace, str);
          case '}': return token(token::right_brace, str);
          case ';': return token(token::semicolon, str);
          case '=': return token(token::equal, str);
          case ',': return token(token::comma, str);
          case ':': return token(token::colon, str);
          case '+': return token(token::plus, str);
          case '(': return token(token::left_paren, str);
          case ')': return token(token::right_paren, str);
          case '@': return token(token::at, str);
          case '-': {
            switch (str[1]) {
              case '-': return token(token::dash_dash, str);
              case '>': return token(token::dash_greater, str);
              default: assert (!"Definition of punctuation_token does not match switch statement");
            }
          }
          default: assert (!"Definition of punctuation_token does not match switch statement"); std::abort();
        }
      }
      found = boost::regex_search(begin, end, results, number_token);
      if (found) {
        std::string str = results[1].str();
        begin = results.suffix().first;
        return token(token::identifier, str);
      }
      found = boost::regex_search(begin, end, results, quoted_string_token);
      if (found) {
        std::string str = results[1].str();
        begin = results.suffix().first;
        // Remove the beginning and ending quotes
        assert (str.size() >= 2);
        str.erase(str.begin());
        str.erase(str.end() - 1);
        // Unescape quotes in the middle, but nothing else (see format spec)
        for (size_t i = 0; i + 1 < str.size() /* May change */; ++i) {
          if (str[i] == '\\' && str[i + 1] == '"') {
            str.erase(str.begin() + i);
            // Don't need to adjust i
          } else if (str[i] == '\\' && str[i + 1] == '\n') {
            str.erase(str.begin() + i);
            str.erase(str.begin() + i);
            --i; // Invert ++ that will be applied
          }
        }
        return token(token::quoted_string, str);
      }
      if (*begin == '<') {
        std::string::const_iterator saved_begin = begin;
        int counter = 0;
        do {
          if (begin == end) throw_lex_error("Unclosed HTML string");
          if (*begin != '<') {
            ++begin;
            continue;
          }
          found = boost::regex_search(begin, end, results, xml_tag_token);
          if (found) {
            begin = results.suffix().first;
            if (results[1].str() == "/") { // Close tag
              --counter;
            } else if (results[2].str() == "/") { // Empty tag
            } else { // Open tag
              ++counter;
            }
            continue;
          }
          found = boost::regex_search(begin, end, results, cdata);
          if (found) {
            begin = results.suffix().first;
            continue;
          }
          throw_lex_error("Invalid contents in HTML string");
        } while (counter > 0);
        return token(token::identifier, std::string(saved_begin, begin));
      } else {
        throw_lex_error("Invalid character");
        return token();
      }
    }

    token peek_token_raw() {
      if (lookahead.empty()) {
        token t = get_token_raw();
        lookahead.push_back(t);
      }
      return lookahead.front();
    }

    token get_token() { // Handle string concatenation
      token t = get_token_raw();
      if (t.type != token::quoted_string) return t;
      std::string str = t.normalized_value;
      while (peek_token_raw().type == token::plus) {
        get_token_raw();
        token t2 = get_token_raw();
        if (t2.type != token::quoted_string) {
          throw_lex_error("Must have quoted string after string concatenation");
        }
        str += t2.normalized_value;
      }
      return token(token::identifier, str); // Note that quoted_string does not get passed to the parser
    }

    void throw_lex_error(const std::string& errmsg) {
      boost::throw_exception(lex_error(errmsg, (begin == end ? '\0' : *begin)));
    }
  };

  struct edge_endpoint {
    bool is_subgraph;
    node_and_port node_ep;
    subgraph_name subgraph_ep;

    static edge_endpoint node(const node_and_port& ep) {
      edge_endpoint r;
      r.is_subgraph = false;
      r.node_ep = ep;
      return r;
    }

    static edge_endpoint subgraph(const subgraph_name& ep) {
      edge_endpoint r;
      r.is_subgraph = true;
      r.subgraph_ep = ep;
      return r;
    }
  };

  struct node_or_subgraph_ref {
    bool is_subgraph;
    std::string name; // Name for subgraphs or nodes, "___root___" for root graph
  };

  static node_or_subgraph_ref noderef(const node_name& n) {
    node_or_subgraph_ref r;
    r.is_subgraph = false;
    r.name = n;
    return r;
  }

  static node_or_subgraph_ref subgraphref(const subgraph_name& n) {
    node_or_subgraph_ref r;
    r.is_subgraph = true;
    r.name = n;
    return r;
  }

  typedef std::vector<node_or_subgraph_ref> subgraph_member_list;

  struct subgraph_info {
    properties def_node_props;
    properties def_edge_props;
    subgraph_member_list members;
  };

  struct parser {
    tokenizer the_tokenizer;
    std::vector<token> lookahead;
    parser_result& r;
    std::map<subgraph_name, subgraph_info> subgraphs;
    std::string current_subgraph_name;
    int sgcounter; // Counter for anonymous subgraphs
    std::set<std::pair<node_name, node_name> > existing_edges; // Used for checking in strict graphs

    subgraph_info& current() {return subgraphs[current_subgraph_name];}
    properties& current_graph_props() {return r.graph_props[current_subgraph_name];}
    subgraph_member_list& current_members() {return current().members;}

    parser(const std::string& gr, parser_result& result)
        : the_tokenizer(gr), lookahead(), r(result), sgcounter(0) {
      current_subgraph_name = "___root___";
      current() = subgraph_info(); // Initialize root graph
      current_graph_props().clear();
      current_members().clear();
    }

    token get() {
      if (lookahead.empty()) {
        token t = the_tokenizer.get_token();
        return t;
      } else {
        token t = lookahead.front();
        lookahead.erase(lookahead.begin());
        return t;
      }
    }

    token peek() {
      if (lookahead.empty()) {
        lookahead.push_back(the_tokenizer.get_token());
      }
      return lookahead.front();
    }

    void error(const std::string& str) {
      boost::throw_exception(parse_error(str, peek()));
    }

    void parse_graph(bool want_directed) {
      bool is_strict = false;
      bool is_directed = false;
      std::string name;
      if (peek().type == token::kw_strict) {get(); is_strict = true;}
      switch (peek().type) {
        case token::kw_graph: is_directed = false; break;
        case token::kw_digraph: is_directed = true; break;
        default: error("Wanted \"graph\" or \"digraph\"");
      }
      r.graph_is_directed = is_directed; // Used to check edges
      r.graph_is_strict = is_strict;
      if (want_directed != r.graph_is_directed) {
        if (want_directed) {
          boost::throw_exception(boost::undirected_graph_error());
        } else {
          boost::throw_exception(boost::directed_graph_error());
        }
      }
      get();
      switch (peek().type) {
        case token::identifier: name = peek().normalized_value; get(); break;
        case token::left_brace: break;
        default: error("Wanted a graph name or left brace");
      }
      if (peek().type == token::left_brace) get(); else error("Wanted a left brace to start the graph");
      parse_stmt_list();
      if (peek().type == token::right_brace) get(); else error("Wanted a right brace to end the graph");
      if (peek().type == token::eof) {} else error("Wanted end of file");
    }

    void parse_stmt_list() {
      while (true) {
        if (peek().type == token::right_brace) return;
        parse_stmt();
        if (peek().type == token::semicolon) get();
      }
    }

    void parse_stmt() {
      switch (peek().type) {
        case token::kw_node:
        case token::kw_edge:
        case token::kw_graph: parse_attr_stmt(); break;
        case token::kw_subgraph:
        case token::left_brace:
        case token::identifier: {
          token id = get();
          if (id.type == token::identifier && peek().type == token::equal) { // Graph property
            get();
            if (peek().type != token::identifier) error("Wanted identifier as right side of =");
            token id2 = get();
            current_graph_props()[id.normalized_value] = id2.normalized_value;
          } else {
            edge_endpoint ep = parse_endpoint_rest(id);
            if (peek().type == token::dash_dash || peek().type == token::dash_greater) { // Edge
              parse_edge_stmt(ep);
            } else {
              if (!ep.is_subgraph) { // Only nodes can have attribute lists
                // This node already exists because of its first mention
                // (properties set to defaults by parse_node_and_port, called
                // by parse_endpoint_rest)
                properties this_node_props;
                if (peek().type == token::left_bracket) {
                  parse_attr_list(this_node_props);
                }
                for (properties::const_iterator i = this_node_props.begin();
                     i != this_node_props.end(); ++i) {
                  // Override old properties with same names
                  r.nodes[ep.node_ep.name][i->first] = i->second;
                }
                current_members().push_back(noderef(ep.node_ep.name));
              } else {
                current_members().push_back(subgraphref(ep.subgraph_ep));
              }
            }
          }
          break;
        }
        default: error("Invalid start token for statement");
      }
    }

    void parse_attr_stmt() {
      switch (get().type) {
        case token::kw_graph: parse_attr_list(current_graph_props()); break;
        case token::kw_node: parse_attr_list(current().def_node_props); break;
        case token::kw_edge: parse_attr_list(current().def_edge_props); break;
        default: assert (!"Bad attr_stmt case"); std::abort();
      }
    }

    edge_endpoint parse_endpoint() {
      switch (peek().type) {
        case token::kw_subgraph:
        case token::left_brace:
        case token::identifier: {
          token first = get();
          return parse_endpoint_rest(first);
        }
        default: {
          error("Wanted \"subgraph\", \"{\", or identifier to start node or subgraph");
          return edge_endpoint();
        }
      }
    }

    edge_endpoint parse_endpoint_rest(const token& first_token) {
      switch (first_token.type) {
        case token::kw_subgraph:
        case token::left_brace: return edge_endpoint::subgraph(parse_subgraph(first_token));
        default: return edge_endpoint::node(parse_node_and_port(first_token));
      }
    }

    subgraph_name parse_subgraph(const token& first_token) {
      std::string name;
      bool is_anonymous = true;
      if (first_token.type == token::kw_subgraph) {
        if (peek().type == token::identifier) {
          name = get().normalized_value;
          is_anonymous = false;
        }
      }
      if (is_anonymous) {
        name = "___subgraph_" +
                 boost::lexical_cast<std::string>(++sgcounter);
      }
      if (subgraphs.find(name) == subgraphs.end()) {
        subgraphs[name] = current(); // Initialize properties and defaults
        subgraphs[name].members.clear(); // Except member list
      }
      if (first_token.type == token::kw_subgraph && peek().type != token::left_brace) {
        if (is_anonymous) error("Subgraph reference needs a name");
        return name;
      }
      subgraph_name old_sg = current_subgraph_name;
      current_subgraph_name = name;
      if (peek().type == token::left_brace) get(); else error("Wanted left brace to start subgraph");
      parse_stmt_list();
      if (peek().type == token::right_brace) get(); else error("Wanted right brace to end subgraph");
      current_subgraph_name = old_sg;
      return name;
    }

    node_and_port parse_node_and_port(const token& name) {
      // A node ID is a node name, followed optionally by a port angle and a
      // port location (in either order); a port location is either :id,
      // :id:id, or :(id,id); the last two forms are treated as equivalent
      // although I am not sure about that.
      node_and_port id;
      id.name = name.normalized_value;
      parse_more:
      switch (peek().type) {
        case token::at: {
          get();
          if (peek().type != token::identifier) error("Wanted identifier as port angle");
          if (id.angle != "") error("Duplicate port angle");
          id.angle = get().normalized_value;
          goto parse_more;
        }
        case token::colon: {
          get();
          if (!id.location.empty()) error("Duplicate port location");
          switch (peek().type) {
            case token::identifier: {
              id.location.push_back(get().normalized_value);
              switch (peek().type) {
                case token::colon: {
                  get();
                  if (peek().type != token::identifier) error("Wanted identifier as port location");
                  id.location.push_back(get().normalized_value);
                  goto parse_more;
                }
                default: goto parse_more;
              }
            }
            case token::left_paren: {
              get();
              if (peek().type != token::identifier) error("Wanted identifier as first element of port location");
              id.location.push_back(get().normalized_value);
              if (peek().type != token::comma) error("Wanted comma between parts of port location");
              get();
              if (peek().type != token::identifier) error("Wanted identifier as second element of port location");
              id.location.push_back(get().normalized_value);
              if (peek().type != token::right_paren) error("Wanted right parenthesis to close port location");
              get();
              goto parse_more;
            }
            default: error("Wanted identifier or left parenthesis as start of port location");
          }
        }
        default: break;
      }
      if (r.nodes.find(id.name) == r.nodes.end()) { // First mention
        r.nodes[id.name] = current().def_node_props;
      }
      return id;
    }

    void parse_edge_stmt(const edge_endpoint& lhs) {
      std::vector<edge_endpoint> nodes_in_chain(1, lhs);
      while (true) {
        bool leave_loop = true;
        switch (peek().type) {
          case token::dash_dash: {
            if (r.graph_is_directed) error("Using -- in directed graph");
            get();
            nodes_in_chain.push_back(parse_endpoint());
            leave_loop = false;
            break;
          }
          case token::dash_greater: {
            if (!r.graph_is_directed) error("Using -> in undirected graph");
            get();
            nodes_in_chain.push_back(parse_endpoint());
            leave_loop = false;
            break;
          }
          default: leave_loop = true; break;
        }
        if (leave_loop) break;
      }
      properties this_edge_props = current().def_edge_props;
      if (peek().type == token::left_bracket) parse_attr_list(this_edge_props);
      assert (nodes_in_chain.size() >= 2); // Should be in node parser otherwise
      for (size_t i = 0; i + 1 < nodes_in_chain.size(); ++i) {
        do_orig_edge(nodes_in_chain[i], nodes_in_chain[i + 1], this_edge_props);
      }
    }

    // Do an edge from the file, the edge may need to be expanded if it connects to a subgraph
    void do_orig_edge(const edge_endpoint& src, const edge_endpoint& tgt, const properties& props) {
      std::set<node_and_port> sources = get_recursive_members(src);
      std::set<node_and_port> targets = get_recursive_members(tgt);
      for (std::set<node_and_port>::const_iterator i = sources.begin(); i != sources.end(); ++i) {
        for (std::set<node_and_port>::const_iterator j = targets.begin(); j != targets.end(); ++j) {
          do_edge(*i, *j, props);
        }
      }
    }

    // Get nodes in an edge_endpoint, recursively
    std::set<node_and_port> get_recursive_members(const edge_endpoint& orig_ep) {
      std::set<node_and_port> result;
      std::vector<edge_endpoint> worklist(1, orig_ep);
      std::set<subgraph_name> done;
      while (!worklist.empty()) {
        edge_endpoint ep = worklist.back();
        worklist.pop_back();
        if (ep.is_subgraph) {
          if (done.find(ep.subgraph_ep) == done.end()) {
            done.insert(ep.subgraph_ep);
            std::map<subgraph_name, subgraph_info>::const_iterator
              info_i = subgraphs.find(ep.subgraph_ep);
            if (info_i != subgraphs.end()) {
              const subgraph_member_list& members = info_i->second.members;
              for (subgraph_member_list::const_iterator i = members.begin();
                   i != members.end(); ++i) {
                node_or_subgraph_ref ref = *i;
                if (ref.is_subgraph) {
                  worklist.push_back(edge_endpoint::subgraph(ref.name));
                } else {
                  node_and_port np;
                  np.name = ref.name;
                  worklist.push_back(edge_endpoint::node(np));
                }
              }
            }
          }
        } else {
          result.insert(ep.node_ep);
        }
      }
      return result;
    }

    // Do a fixed-up edge, with only nodes as endpoints
    void do_edge(const node_and_port& src, const node_and_port& tgt, const properties& props) {
      if (r.graph_is_strict) {
        if (src.name == tgt.name) return;
        std::pair<node_name, node_name> tag(src.name, tgt.name);
        if (existing_edges.find(tag) != existing_edges.end()) {
          return; // Parallel edge
        }
        existing_edges.insert(tag);
      }
      edge_info e;
      e.source = src;
      e.target = tgt;
      e.props = props;
      r.edges.push_back(e);
    }

    void parse_attr_list(properties& props) {
      while (true) {
        if (peek().type == token::left_bracket) get(); else error("Wanted left bracket to start attribute list");
        while (true) {
          switch (peek().type) {
            case token::right_bracket: break;
            case token::identifier: {
              std::string lhs = get().normalized_value;
              std::string rhs = "true";
              if (peek().type == token::equal) {
                get();
                if (peek().type != token::identifier) error("Wanted identifier as value of attributed");
                rhs = get().normalized_value;
              }
              props[lhs] = rhs;
              break;
            }
            default: error("Wanted identifier as name of attribute");
          }
          if (peek().type == token::comma) {get(); continue;}
          break;
        }
        if (peek().type == token::right_bracket) get(); else error("Wanted right bracket to end attribute list");
        if (peek().type != token::left_bracket) break;
      }
    }
  };

  void parse_graphviz_from_string(const std::string& str, parser_result& result, bool want_directed) {
    parser p(str, result);
    p.parse_graph(want_directed);
  }

  // Some debugging stuff
  std::ostream& operator<<(std::ostream& o, const node_and_port& n) {
    o << n.name;
    for (size_t i = 0; i < n.location.size(); ++i) {
      o << ":" << n.location[i];
    }
    if (!n.angle.empty()) o << "@" << n.angle;
    return o;
  }

  // Can't be operator<< because properties is just an std::map
  std::string props_to_string(const properties& props) {
    std::string result = "[";
    for (properties::const_iterator i = props.begin(); i != props.end(); ++i) {
      if (i != props.begin()) result += ", ";
      result += i->first + "=" + i->second;
    }
    result += "]";
    return result;
  }

  void translate_results_to_graph(const parser_result& r, ::boost::detail::graph::mutate_graph* mg) {
    typedef boost::detail::graph::node_t vertex;
    typedef boost::detail::graph::edge_t edge;
    for (std::map<node_name, properties>::const_iterator i = r.nodes.begin(); i != r.nodes.end(); ++i) {
        //std::cerr << i->first << " " << props_to_string(i->second) << std::endl;
      mg->do_add_vertex(i->first);
      for (properties::const_iterator j = i->second.begin(); j != i->second.end(); ++j) {
        mg->set_node_property(j->first, i->first, j->second);
      }
    }
    for (std::vector<edge_info>::const_iterator i = r.edges.begin(); i != r.edges.end(); ++i) {
      const edge_info& ei = *i;
      //std::cerr << ei.source << " -> " << ei.target << " " << props_to_string(ei.props) << std::endl;
      edge e = edge::new_edge();
      mg->do_add_edge(e, ei.source.name, ei.target.name);
      for (properties::const_iterator j = ei.props.begin(); j != ei.props.end(); ++j) {
        mg->set_edge_property(j->first, e, j->second);
      }
    }
    std::map<subgraph_name, properties>::const_iterator root_graph_props_i = r.graph_props.find("___root___");
    assert (root_graph_props_i != r.graph_props.end()); // Should not happen
    const properties& root_graph_props = root_graph_props_i->second;
    //std::cerr << "ending graph " << props_to_string(root_graph_props) << std::endl;
    for (properties::const_iterator i = root_graph_props.begin(); i != root_graph_props.end(); ++i) {
      mg->set_graph_property(i->first, i->second);
    }
  }

} // end namespace read_graphviz_detail

namespace detail {
  namespace graph {

    bool read_graphviz(const std::string& str, boost::detail::graph::mutate_graph* mg) {
      read_graphviz_detail::parser_result parsed_file;
      read_graphviz_detail::parse_graphviz_from_string(str, parsed_file, mg->is_directed());
      read_graphviz_detail::translate_results_to_graph(parsed_file, mg);
      return true;
    }

  } // end namespace graph
} // end namespace detail

} // end namespace boost

// GraphViz format notes (tested using "dot version 1.13 (v16) (Mon August 23,
// 2004)", grammar from references in read_graphviz_new.hpp):

// Subgraphs don't nest (all a0 subgraphs are the same thing), but a node or
// subgraph can have multiple parents (sources online say that the layout
// algorithms can't handle non-tree structures of clusters, but it seems to
// read them the same from the file).  The containment relation is required to
// be a DAG, though; it appears that a node or subgraph can't be moved into an
// ancestor of a subgraph where it already was (we don't enforce that but do a
// DFS when finding members to prevent cycles).  Nodes get their properties by
// when they are first mentioned, and can only have them overridden after that
// by explicit properties on that particular node.  Closing and reopening the
// same subgraph name adds to its members, and graph properties and node/edge
// defaults are preserved in that subgraph.  The members of a subgraph used in
// an edge are gathered when the edge is read, even if new members are added to
// the subgraph later.  Ports are allowed in a lot more places in the grammar
// than Dot uses.  For example, declaring a node seems to ignore ports, and I
// don't think it's possible to set properties on a particular port.  Adding an
// edge between two ports on the same node seems to make Dot unhappy (crashed
// for me).

// Test graph for GraphViz behavior on strange combinations of subgraphs and
// such.  I don't have anywhere else to put this file.

#if 0
dIGRaph foo {
  node [color=blue]
  subgraph a -> b
  subgraph a {c}
  subgraph a -> d
  subgraph a {node [color=red]; e}
  subgraph a -> f
  subgraph a {g} -> h
  subgraph a {node [color=green]; i} -> j
  subgraph a {node [color=yellow]}

  subgraph a0 {node [color=black]; subgraph a1 {node [color=white]}}
  node [color=pink] zz
  subgraph a0 {x1}
  subgraph a0 {subgraph a1 {x2}}

  subgraph a0 -> x3
  subgraph a0 {subgraph a1 -> x3}
  x3
  subgraph a0 {subgraph a0 {node [color=xxx]; x2} x7}
  x2 [color=yyy]
  subgraph cluster_ax {foo; subgraph a0}
  subgraph a0 {foo2}
  subgraph cluster_ax {foo3}
  // subgraph a0 -> subgraph a0

  bgcolor=yellow
  subgraph cluster_a2 {y1}
  // y1:n -> y1:(s,3)@se
  y1@se [color=green]
  y1@n [color=red]
}
#endif