summaryrefslogtreecommitdiffstats
path: root/lib/optparse.rb
blob: 1b083b8e6e1de287b0d8b52782b32555d7f78474 (plain)
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
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
#
# optparse.rb - command-line option analysis with the OptionParser class.
# 
# Author:: Nobu Nakada
# Documentation:: Nobu Nakada and Gavin Sinclair.
#
# See OptionParser for documentation. 
#


# == Developer Documentation (not for RDoc output) 
# 
# === Class tree
#
# - OptionParser:: front end
# - OptionParser::Switch:: each switches
# - OptionParser::List:: options list
# - OptionParser::ParseError:: errors on parsing
#   - OptionParser::AmbiguousOption
#   - OptionParser::NeedlessArgument
#   - OptionParser::MissingArgument
#   - OptionParser::InvalidOption
#   - OptionParser::InvalidArgument
#     - OptionParser::AmbiguousArgument
#
# === Object relationship diagram
#
#  +--------------+
#  | OptionParser |<>-----+
#  +--------------+       |                      +--------+
#                         |                    ,-| Switch |
#       on_head -------->+---------------+    /  +--------+
#       accept/reject -->| List          |<|>-
#                        |               |<|>-  +----------+
#       on ------------->+---------------+    `-| argument |
#                          :           :        |  class   |
#                        +---------------+      |==========|
#       on_tail -------->|               |      |pattern   |
#                        +---------------+      |----------|
#  OptionParser.accept ->| DefaultList   |      |converter |
#               reject   |(shared between|      +----------+
#                        | all instances)|
#                        +---------------+


#
# == OptionParser
#
# === Introduction
#
# OptionParser is a class for command-line option analysis.  It is much more
# advanced, yet also easier to use, than GetoptLong, and is a more Ruby-oriented
# solution.
#
# === Features
# 
# 1. The argument specification and the code to handle it are written in the same
#    place.
# 2. It can output an option summary; you don't need to maintain this string
#    separately.
# 3. Optional and mandatory arguments are specified very gracefully.
# 4. Arguments can be automatically converted to a specified class.
# 5. Arguments can be restricted to a certain set.
#
# All of these features are demonstrated in the example below.
#
# === Example
#
# The following example is a complete Ruby program.  You can run it and see the
# effect of specifying various options.  This is probably the best way to learn
# the features of +optparse+.
#
#   require 'optparse'
#   require 'optparse/time'
#   require 'ostruct'
#   require 'pp'
#   
#   class OptparseExample
#   
#     CODES = %w[iso-2022-jp shift_jis euc-jp utf8 binary]
#     CODE_ALIASES = { "jis" => "iso-2022-jp", "sjis" => "shift_jis" }
#   
#     #
#     # Return a structure describing the options.
#     #
#     def self.parse(args)
#       # The options specified on the command line will be collected in *options*.
#       # We set default values here.
#       options = OpenStruct.new
#       options.library = []
#       options.inplace = false
#       options.encoding = "utf8"
#       options.transfer_type = :auto
#       options.verbose = false
#       
#       opts = OptionParser.new do |opts|
#         opts.banner = "Usage: example.rb [options]"
#       
#         opts.separator ""
#         opts.separator "Specific options:"
#       
#         # Mandatory argument.
#         opts.on("-r", "--require LIBRARY",
#                 "Require the LIBRARY before executing your script") do |lib|
#           options.library << lib
#         end
#       
#         # Optional argument; multi-line description.
#         opts.on("-i", "--inplace [EXTENSION]",
#                 "Edit ARGV files in place",
#                 "  (make backup if EXTENSION supplied)") do |ext|
#           options.inplace = true
#           options.extension = ext || ''
#           options.extension.sub!(/\A\.?(?=.)/, ".")  # Ensure extension begins with dot.
#         end
#       
#         # Cast 'delay' argument to a Float.
#         opts.on("--delay N", Float, "Delay N seconds before executing") do |n|
#           options.delay = n
#         end
#       
#         # Cast 'time' argument to a Time object.
#         opts.on("-t", "--time [TIME]", Time, "Begin execution at given time") do |time|
#           options.time = time
#         end
#       
#         # Cast to octal integer.
#         opts.on("-F", "--irs [OCTAL]", OptionParser::OctalInteger,
#                 "Specify record separator (default \\0)") do |rs|
#           options.record_separator = rs
#         end
#       
#         # List of arguments.
#         opts.on("--list x,y,z", Array, "Example 'list' of arguments") do |list|
#           options.list = list
#         end
#       
#         # Keyword completion.  We are specifying a specific set of arguments (CODES
#         # and CODE_ALIASES - notice the latter is a Hash), and the user may provide
#         # the shortest unambiguous text.
#         code_list = (CODE_ALIASES.keys + CODES).join(',')
#         opts.on("--code CODE", CODES, CODE_ALIASES, "Select encoding",
#                 "  (#{code_list})") do |encoding|
#           options.encoding = encoding
#         end
#       
#         # Optional argument with keyword completion.
#         opts.on("--type [TYPE]", [:text, :binary, :auto],
#                 "Select transfer type (text, binary, auto)") do |t|
#           options.transfer_type = t
#         end
#       
#         # Boolean switch.
#         opts.on("-v", "--[no-]verbose", "Run verbosely") do |v|
#           options.verbose = v
#         end
#       
#         opts.separator ""
#         opts.separator "Common options:"
#       
#         # No argument, shows at tail.  This will print an options summary.
#         # Try it and see!
#         opts.on_tail("-h", "--help", "Show this message") do
#           puts opts
#           exit
#         end
#       
#         # Another typical switch to print the version.
#         opts.on_tail("--version", "Show version") do
#           puts OptionParser::Version.join('.')
#           exit
#         end
#       end
#       
#       opts.parse!(args)
#       options
#     end  # parse()
#   
#   end  # class OptparseExample
#   
#   options = OptparseExample.parse(ARGV)
#   pp options
#
# Note: some bugs were fixed between 1.8.0 and 1.8.1.  If you experience trouble
# with the above code, keep this in mind.
#
# === Further documentation
#
# The methods are not individually documented at this stage.  The above example
# should be enough to learn how to use this class.  If you have any questions,
# email me (gsinclair@soyabean.com.au) and I will update this document.
#
class OptionParser
  # :stopdoc:
  RCSID = %w$Id$[1..-1].each {|s| s.freeze}.freeze
  Version = (RCSID[1].split('.').collect {|s| s.to_i}.extend(Comparable).freeze if RCSID[1])
  LastModified = (Time.gm(*RCSID[2, 2].join('-').scan(/\d+/).collect {|s| s.to_i}) if RCSID[2])
  Release = RCSID[2]

  NoArgument = [NO_ARGUMENT = :NONE, nil].freeze
  RequiredArgument = [REQUIRED_ARGUMENT = :REQUIRED, true].freeze
  OptionalArgument = [OPTIONAL_ARGUMENT = :OPTIONAL, false].freeze
  # :startdoc:

  #
  # Keyword completion module.  This allows partial arguments to be specified
  # and resolved against a list of acceptable values.
  #
  module Completion
    def complete(key, pat = nil)
      pat ||= Regexp.new('\A' + Regexp.quote(key).gsub(/\w+\b/, '\&\w*'),
                         ignore_case?)
      canon, sw, k, v, cn = nil
      candidates = []
      each do |k, *v|
        (if Regexp === k
           kn = nil
           k === key
         else
           kn = defined?(k.id2name) ? k.id2name : k
           pat === kn
         end) or next
        v << k if v.empty?
        candidates << [k, v, kn]
      end
      candidates = candidates.sort_by {|k, v, kn| kn.size}
      if candidates.size == 1
        canon, sw, * = candidates[0]
      elsif candidates.size > 1
        canon, sw, cn = candidates.shift
        candidates.each do |k, v, kn|
          next if sw == v
          if String === cn and String === kn
            if cn.rindex(kn, 0)
              canon, sw, cn = k, v, kn
              next
            elsif kn.rindex(cn, 0)
              next
            end
          end
          throw :ambiguous, key
        end
      end
      if canon
        block_given? or return key, *sw
        yield(key, *sw)
      end
    end

    def convert(opt = nil, val = nil, *)
      val
    end

    def ignore_case?
      false
    end
  end


  #
  # Map from option/keyword string to object with completion.
  #
  class OptionMap < Hash
    include Completion
  end
  class OptionCaseMap < OptionMap
    def ignore_case?
      true
    end
  end


  #
  # Individual switch class.  Not important to the user.
  #
  # Defined within Switch are several Switch-derived classes: NoArgument,
  # RequiredArgument, etc. 
  #
  class Switch
    attr_reader :pattern, :conv, :short, :long, :arg, :desc, :block

    #
    # Guesses argument style from +arg+.  Returns corresponding
    # OptionParser::Switch class (OptionalArgument, etc.).
    #
    def self.guess(arg)
      case arg
      when ""
        t = self
      when /\A=?\[/
        t = Switch::OptionalArgument
      when /\A\s+\[/
        t = Switch::PlacedArgument
      else
        t = Switch::RequiredArgument
      end
      self >= t or incompatible_argument_styles(arg, t)
      t
    end

    def self.incompatible_argument_styles(arg, t)
      raise ArgumentError, "#{arg}: incompatible argument styles\n  #{self}, #{t}"
    end

    def self.pattern
      NilClass
    end

    def initialize(pattern = nil, conv = nil,
                   short = nil, long = nil, arg = nil,
                   desc = ([] if short or long), block = Proc.new)
      raise if Array === pattern
      @pattern, @conv, @short, @long, @arg, @desc, @block =
        pattern, conv, short, long, arg, desc, block
    end

    #
    # OptionParser::Switch#parse_arg(arg) {non-serious error handler}
    #
    # Parses argument and returns rest of ((|arg|)), and matched portion
    # to the argument pattern.
    #  :Parameters:
    #    : ((|arg|))
    #      option argument to be parsed.
    #    : (({block}))
    #      yields when the pattern doesn't match sub-string.
    #
    def parse_arg(arg)
      pattern or return nil, arg
      unless m = pattern.match(arg)
        yield(InvalidArgument, arg)
        return arg, nil
      end
      if String === m
        m = [s = m]
      else
        m = m.to_a
        s = m[0]
        return nil, m unless String === s
      end
      raise InvalidArgument, arg unless arg.rindex(s, 0)
      return nil, m if s.length == arg.length
      yield(InvalidArgument, arg) # didn't match whole arg
      return arg[s.length..-1], m
    end
    private :parse_arg

    #
    # OptionParser::Switch#conv_arg(arg, val) {semi-error handler}
    #
    # Parses argument, convert and returns ((|arg|)), ((|block|)) and
    # result of conversion.
    #  : Arguments to ((|@conv|))
    #    substrings matched to ((|@pattern|)), ((|$&|)), ((|$1|)),
    #    ((|$2|)) and so on.
    #  :Parameters:
    #    : ((|arg|))
    #      argument string follows the switch.
    #    : ((|val|))
    #      following argument.
    #    : (({block}))
    #      (({yields})) at semi-error condition, instead of raises exception.
    #
    def conv_arg(arg, val = nil)
      if block
        if conv
          val = conv.call(*val)
        else
          val = *val
        end
        return arg, block, val
      else
        return arg, nil
      end
    end
    private :conv_arg

    #
    # OptionParser::Switch#summarize(sdone, ldone, width, max, indent)
    #
    # Makes summary strings.
    #  :Parameters:
    #    : ((|sdone|))
    #      already summarized short style options keyed hash.
    #    : ((|ldone|))
    #      already summarized long style options keyed hash.
    #    : ((|width|))
    #      width of left side, option part. in other word, right side,
    #      description part strings start at ((|width|)) column.
    #    : ((|max|))
    #      maximum width of left side, options are filled within ((|max|)) columns.
    #    : ((|indent|))
    #      prefix string indents each summarized lines.
    #    : (({block}))
    #      to be passed each lines(without newline).
    #
    def summarize(sdone = [], ldone = [], width = 1, max = width - 1, indent = "")
      sopts, lopts, s = [], [], nil
      @short.each {|s| sdone.fetch(s) {sopts << s}; sdone[s] = true} if @short
      @long.each {|s| ldone.fetch(s) {lopts << s}; ldone[s] = true} if @long
      return if sopts.empty? and lopts.empty? # completely hidden

      left = [sopts.join(', ')]
      right = desc.dup

      while s = lopts.shift
        l = left[-1].length + s.length
        l += arg.length if left.size == 1 && arg
        l < max or left << ''
        left[-1] << if left[-1].empty? then ' ' * 4 else ', ' end << s
      end

      left[0] << arg if arg
      mlen = left.collect {|s| s.length}.max.to_i
      while mlen > width and l = left.shift
        mlen = left.collect {|s| s.length}.max.to_i if l.length == mlen
        yield(indent + l)
      end

      while (l = left.shift; r = right.shift; l or r)
        l = l.to_s.ljust(width) + ' ' + r if r and !r.empty?
        yield(indent + l)
      end

      self
    end

    #
    # Switch that takes no arguments.
    #
    class NoArgument < self
      #
      # Raises an exception if any arguments given.
      #
      def parse(arg, argv, &error)
        yield(NeedlessArgument, arg) if arg
        conv_arg(arg)
      end
      def self.incompatible_argument_styles(*)
      end
      def self.pattern
        Object
      end
    end

    #
    # Switch that takes an argument.
    #
    class RequiredArgument < self
      #
      # Raises an exception if argument is not present.
      #
      def parse(arg, argv, &error)
        unless arg
          raise MissingArgument if argv.empty?
          arg = argv.shift
        end
        conv_arg(*parse_arg(arg, &error))
      end
    end

    #
    # Switch that can omit argument.
    #
    class OptionalArgument < self
      #
      # Parses argument if given, or uses default value.
      #
      def parse(arg, argv, &error)
        if arg
          conv_arg(*parse_arg(arg, &error))
        else
          conv_arg(arg)
        end
      end
    end

    #
    # ?
    #
    class PlacedArgument < self
      #
      # ?
      #
      def parse(arg, argv, &error)
        if !(val = arg) and (argv.empty? or /\A-/ =~ (val = argv[0]))
          return nil, block, nil
        end
        opt = (val = parse_arg(val, &error))[1]
        val = conv_arg(*val)
        if opt and !arg
          argv.shift
        else
          val[0] = nil
        end
        val
      end
    end
  end

  #
  # Simple option list providing mapping from short and/or long option
  # string to ((<OptionParser::Switch>)), and mapping from acceptable
  # argument to matching pattern and converter pair.  Also provides
  # summary feature.
  #
  class List
    # Map from acceptable argument types to pattern and converter pairs.
    attr_reader :atype
    
    # Map from short style option switches to actual switch objects.
    attr_reader :short
    
    # Map from long style option switches to actual switch objects.
    attr_reader :long
    
    # List of all switches and summary string.
    attr_reader :list

    #
    # Just initializes all instance variables.
    #
    def initialize
      @atype = {}
      @short = OptionMap.new
      @long = OptionCaseMap.new
      @list = []
    end

    #
    # See OptionParser.accept.
    #
    def accept(t, pat = /.*/, &block)
      if pat
        pat.respond_to?(:match) or raise TypeError, "has no `match'"
      else
        pat = t if t.respond_to?(:match)
      end
      unless block
        block = pat.method(:convert).to_proc if pat.respond_to?(:convert)
      end
      @atype[t] = [pat, block]
    end

    #
    # See OptionParser.reject.
    #
    def reject(t)
      @atype.delete(t)
    end

    #
    # OptionParser::List#update(sw, sopts, lopts, nlopts = nil)
    #
    # Adds ((|sw|)) according to ((|sopts|)), ((|lopts|)) and
    # ((|nlopts|)).
    #  :Parameters:
    #    : ((|sw|))
    #      ((<OptionParser::Switch>)) instance to be added.
    #    : ((|sopts|))
    #      short style options list.
    #    : ((|lopts|))
    #      long style options list.
    #    : ((|nlopts|))
    #      negated long style options list.
    #
    def update(sw, sopts, lopts, nsw = nil, nlopts = nil)
      o = nil
      sopts.each {|o| @short[o] = sw} if sopts
      lopts.each {|o| @long[o] = sw} if lopts
      nlopts.each {|o| @long[o] = nsw} if nsw and nlopts
      used = @short.invert.update(@long.invert)
      @list.delete_if {|o| Switch === o and !used[o]}
    end
    private :update

    #
    # OptionParser::List#prepend(switch, short_opts, long_opts, nolong_opts)
    #
    # Inserts ((|switch|)) at head of the list, and associates short,
    # long and negated long options.
    def prepend(*args)
      update(*args)
      @list.unshift(args[0])
    end

    #
    # OptionParser::List#append(switch, short_opts, long_opts, nolong_opts)
    #
    # Appends ((|switch|)) at tail of the list, and associates short,
    # long and negated long options.
    #  :Parameters:
    #    : ((|switch|))
    #      ((<OptionParser::Switch>)) instance to be inserted.
    #    : ((|short_opts|))
    #      list of short style options.
    #    : ((|long_opts|))
    #      list of long style options.
    #    : ((|nolong_opts|))
    #      list of long style options with (({"no-"})) prefix.
    def append(*args)
      update(*args)
      @list.push(args[0])
    end

    #
    # OptionParser::List#search(id, key) [{block}]
    #
    # Searches ((|key|)) in ((|id|)) list.
    #  :Parameters:
    #    : ((|id|))
    #      searching list.
    #    : ((|k|))
    #      searching key.
    #    : (({block}))
    #      yielded with the found value when succeeded.
    #
    def search(id, key)
      if list = __send__(id)
        val = list.fetch(key) {return nil}
        return val unless block_given?
        yield(val)
      end
    end

    #
    # OptionParser::List#complete(id, opt, *pat, &block)
    #
    # Searches list ((|id|)) for ((|opt|)) and ((|*pat|)).
    #  :Parameters:
    #    : ((|id|))
    #      searching list.
    #    : ((|opt|))
    #      searching key.
    #    : ((|*pat|))
    #      optional pattern for completion.
    #    : (({block}))
    #      yielded with the found value when succeeded.
    #
    def complete(id, opt, *pat, &block)
      __send__(id).complete(opt, *pat, &block)
    end

    #
    # OptionParser::List#summarize(*args) {...}
    #
    # Making summary table, yields the (({block})) with each lines.
    # Each elements of (({@list})) should be able to (({summarize})).
    #  :Parameters:
    #    : ((|args|))
    #      passed to elements#summarize through.
    #    : (({block}))
    #      to be passed each lines(without newline).
    #
    def summarize(*args, &block)
      list.each do |opt|
        if opt.respond_to?(:summarize) # perhaps OptionParser::Switch
          opt.summarize(*args, &block)
        elsif opt.empty?
          yield("")
        else
          opt.each(&block)
        end
      end
    end
  end

  #
  # Hash with completion search feature.  See Completion module.
  #
  class CompletingHash < Hash
    include Completion

    #
    # OptionParser::CompletingHash#match(key)
    #
    # Completion for hash key.
    #
    def match(key)
      return key, *fetch(key) {
        raise AmbiguousArgument, catch(:ambiguous) {return complete(key)}
      }
    end
  end

  #
  # OptionParser::ArgumentStyle
  # Enumeration of acceptable argument styles; possible values are:
  # : OptionParser::NO_ARGUMENT
  #   the switch takes no arguments. ((({:NONE}))) 
  # : OptionParser::REQUIRED_ARGUMENT
  #   the switch requires an argument. ((({:REQUIRED})))
  # : OptionParser::OPTIONAL_ARGUMENT
  #   the switch requires an optional argument, that is, may take or
  #   not. ((({:OPTIONAL})))
  #
  # Use like (({--switch=argument}))(long style) or
  # (({-Xargument}))(short style). For short style, only portion
  # matched to ((<argument pattern>)) is dealed as argument.
  #

  # :stopdoc: 
  ArgumentStyle = {}
  NoArgument.each {|el| ArgumentStyle[el] = Switch::NoArgument}
  RequiredArgument.each {|el| ArgumentStyle[el] = Switch::RequiredArgument}
  OptionalArgument.each {|el| ArgumentStyle[el] = Switch::OptionalArgument}
  ArgumentStyle.freeze

  #
  # OptionParser::DefaultList
  #
  # Switches common used such as '--', and also provides default
  # argument classes
  #
  
  DefaultList = List.new
  DefaultList.short['-'] = Switch::NoArgument.new {}
  DefaultList.long[''] = Switch::NoArgument.new {throw :terminate}

  #
  # Default options, which never appear in option summary.
  #   --help
  #   Shows option summary.
  #   --version
  #   Shows version string if (({::Version})) is defined.
  #
  DefaultList.long['help'] = Switch::NoArgument.new do
    puts ARGV.options
    exit
  end
  DefaultList.long['version'] = Switch::OptionalArgument.new do |pkg|
    if pkg
      begin
        require 'optparse/version'
      rescue LoadError
        pkg = nil
      else
        show_version(*pkg.split(/,/))
      end
    end
    unless pkg
      v = ARGV.options.ver and puts v
    end
    exit
  end

  # :startdoc:

  #
  # Class methods
  #

=begin
--- OptionParser.with([banner[, width[, indent]]]) [{...}]
    Initializes new instance, and evaluates the block in context of
    the instance if called as iterator.  This behavior is equivalent
    to older (({new})).  This is ((*deprecated*)) method.
    
    cf. ((<OptionParser.new>))
    :Parameters:
      : ((|banner|))
        banner message.
      : ((|width|))
        summary width.
      : ((|indent|))
        summary indent.
      : (({block}))
        to be evaluated in the new instance context.
=end #'#"#`#
  def self.with(*args, &block)
    opts = new(*args)
    opts.instance_eval(&block)
    opts
  end

=begin
--- OptionParser.inc(arg[, default])
--- OptionParser#inc(arg[, default])
    Returns incremented value of ((|default|)) according to ((|arg|)).
=end
  def self.inc(arg, default = nil)
    case arg
    when Integer
      arg.nonzero?
    when nil
      default.to_i + 1
    end
  end
  def inc(*args)
    self.class.inc(*args)
  end

=begin
--- OptionParser.new([banner[, width[, indent]]]) [{...}]
    Initializes the instance, and yields itself if called as iterator.
    :Parameters:
      : ((|banner|))
        banner message.
      : ((|width|))
        summary width.
      : ((|indent|))
        summary indent.
      : (({block}))
        to be evaluated in the new instance context.
=end #'#"#`#
  def initialize(banner = nil, width = 32, indent = ' ' * 4)
    @stack = [DefaultList, List.new, List.new]
    @program_name = nil
    @banner = banner
    @summary_width = width
    @summary_indent = indent
    yield self if block_given?
  end

=begin
--- OptionParser.terminate([arg])
    Terminates option parsing. Optional parameter ((|arg|)) would be
    pushed back if given.
    :Parameters:
      : ((|arg|))
        string pushed back to be first non-option argument
=end #'#"#`#
  def terminate(arg = nil)
    self.class.terminate(arg)
  end
  def self.terminate(arg = nil)
    throw :terminate, arg
  end

  @stack = [DefaultList]
  def self.top() DefaultList end

=begin
--- OptionParser.accept(t, [pat]) {...}
--- OptionParser#accept(t, [pat]) {...}
    Directs to accept specified class argument.
    :Parameters:
      : ((|t|))
        argument class specifier, any object including Class.
      : ((|pat|))
        pattern for argument, defaulted to ((|t|)) if it respond to (({match})).
      : (({block}))
        receives argument string and should be convert to desired class.
=end #'#"#`#
  def accept(*args, &blk) top.accept(*args, &blk) end
  def self.accept(*args, &blk) top.accept(*args, &blk) end

=begin
--- OptionParser.reject(t)
--- OptionParser#reject(t)
    Directs to reject specified class argument.
    :Parameters:
      : ((|t|))
        argument class specifier, any object including Class.
=end #'#"#`#
  def reject(*args, &blk) top.reject(*args, &blk) end
  def self.reject(*args, &blk) top.reject(*args, &blk) end


=begin
=== Instance methods
=end #'#"#`#

=begin
--- OptionParser#banner
--- OptionParser#banner=(heading)
    Heading banner preceding summary.
--- OptionParser#summary_width
--- OptionParser#summary_width=(width)
    Width for option list portion of summary. Must be (({Numeric})).
--- OptionParser#summary_indent
--- OptionParser#summary_indent=(indent)
    Indentation for summary. Must be (({String})) (or have (({+ String}))).
--- OptionParser#program_name
--- OptionParser#program_name=(name)
    Program name to be emitted in error message and default banner,
    defaulted to (({$0})).
=end #'#"#`#
  attr_writer :banner, :program_name
  attr_accessor :summary_width, :summary_indent

  def banner
    @banner ||= "Usage: #{program_name} [options]"
  end

  def program_name
    @program_name || File.basename($0, '.*')
  end

# for experimental cascading :-)
  alias set_banner banner=
  alias set_program_name program_name=
  alias set_summary_width summary_width=
  alias set_summary_indent summary_indent=

=begin
--- OptionParser#version
--- OptionParser#version=(ver)
    Version.
--- OptionParser#release
--- OptionParser#release=(rel)
    Release code.
--- OptionParser#ver
    Returns version string from ((<program_name>)), (({version})) and
    (({release})).
=end #'#"#`#
  attr_writer :version, :release

  def version
    @version || (defined?(::Version) && ::Version) || (defined?(::VERSION) && ::VERSION)
  end

  def release
    @release || (defined?(::Release) && ::Release) || (defined?(::RELEASE) && ::RELEASE)
  end

  def ver
    if v = version
      str = "#{program_name} #{[v].join('.')}"
      str << " (#{v})" if v = release
      str
    end
  end

  def warn(mesg = $!)
    super(program_name + ': ' + mesg)
  end

  def abort(mesg = $!)
    super(program_name + ': ' + mesg)
  end

=begin
--- OptionParser#top
    Subject of ((<on>))/((<on_head>)), ((<accept>))/((<reject>)).
=end #'#"#`#
  def top
    @stack[-1]
  end

=begin
--- OptionParser#base
    Subject of ((<on_tail>)).
=end #'#"#`#
  def base
    @stack[1]
  end

=begin
--- OptionParser#new
    Pushes a new (({List})).
=end #'#"#`#
  def new
    @stack.push(List.new)
    if block_given?
      yield self
    else
      self
    end
  end

=begin
--- OptionParser#remove
    Removes the last (({List})).
=end #'#"#`#
  def remove
    @stack.pop
  end


=begin
--- OptionParser#summarize(to = [], width = @summary_width, max = width - 1, indent = @summary_indent)
    Puts option summary into ((|to|)), and returns ((|to|)).
    :Parameters:
      : ((|to|))
        output destination, which must have method ((|<<|)). Defaulted to (({[]})).
      : ((|width|))
        width of left side. Defaulted to ((|@summary_width|))
      : ((|max|))
        maximum length allowed for left side. Defaulted to (({((|width|)) - 1}))
      : ((|indent|))
        indentation. Defaulted to ((|@summary_indent|))
      : (({block}))
        yields with each line if called as iterator.
=end #'#"#`#
  def summarize(to = [], width = @summary_width, max = width - 1, indent = @summary_indent, &blk)
    visit(:summarize, {}, {}, width, max, indent, &(blk || proc {|l| to << l + $/}))
    to
  end

=begin
--- OptionParser#help
--- OptionParser#to_s
    Returns option summary string.
=end #'#"#`#
  def help; summarize(banner.to_s.sub(/\n?\z/, "\n")) end
  alias to_s help

=begin
--- OptionParser#to_a
    Returns option summary list.
=end #'#"#`#
  def to_a; summarize(banner.to_a.dup) end


=begin
--- OptionParser#switch
    Creates ((<OptionParser::Switch>)).
    :Parameters:
      : ((|*opts|))
        option definition:
        : argument style
          see ((<OptionParser::ArgumentStyle>))
        : argument pattern
          acceptable option argument format, must pre-defined with
          ((<OptionParser.accept>)) or ((<OptionParser#accept>)), or
          (({Regexp})). This can appear once or assigned as (({String}))
          if not present, otherwise causes exception (({ArgumentError})).
          
          cf. ((<Acceptable argument classes>)).
        : Hash
        : Array
          possible argument values.
        : Proc
        : Method
          alternative way to give the ((*handler*)).
        : "--switch=MANDATORY", "--switch[=OPTIONAL]", "--switch"
          specifies long style switch that takes ((*mandatory*)),
          ((*optional*)) and ((*no*)) argument, respectively.
        : "-xMANDATORY", "-x[OPTIONAL]", "-x"
          specifies short style switch that takes ((*mandatory*)),
          ((*optional*)) and ((*no*)) argument, respectively.
        : "-[a-z]MANDATORY", "-[a-z][OPTIONAL]", "-[a-z]"
          special form short style switch that matches character
          range(not fullset of regular expression).
        : "=MANDATORY", "=[OPTIONAL]"
          argument style and description.
        : "description", ...
          ((*description*)) for this option.
      : (({block}))
        ((*handler*)) to convert option argument to arbitrary (({Class})).
=end #'#"#`#
=begin private
--- OptionParser#notwice(obj, prv, msg)
    Checks never given twice an argument.
    ((*Called from OptionParser#switch only*))
    :Parameters:
      : ((|obj|))
        new argument.
      : ((|prv|))
        previously specified argument.
      : ((|msg|))
        exception message
=end #'#"#`#
  def notwice(obj, prv, msg)
    unless !prv or prv == obj
      begin
        raise ArgumentError, "argument #{msg} given twice: #{obj}"
      rescue
        $@[0, 2] = nil
        raise
      end
    end
    obj
  end
  private :notwice

  def make_switch(*opts, &block)
    short, long, nolong, style, pattern, conv, not_pattern, not_conv, not_style = [], [], []
    ldesc, sdesc, desc, arg = [], [], []
    default_style = Switch::NoArgument
    default_pattern = nil
    klass = nil
    o = nil
    n, q, a = nil

    opts.each do |o|
      # argument class
      next if search(:atype, o) do |pat, c|
        klass = notwice(o, klass, 'type')
        if not_style and not_style != Switch::NoArgument
          not_pattern, not_conv = pat, c
        else
          default_pattern, conv = pat, c
        end
      end

      # directly specified pattern(any object possible to match)
      if !(String === o) and o.respond_to?(:match)
        pattern = notwice(o, pattern, 'pattern')
        conv = (pattern.method(:convert).to_proc if pattern.respond_to?(:convert))
        next
      end

      # anything others
      case o
      when Proc, Method
        block = notwice(o, block, 'block')
      when Array, Hash
        case pattern
        when CompletingHash
        when nil
          pattern = CompletingHash.new
          conv = (pattern.method(:convert).to_proc if pattern.respond_to?(:convert))
        else
          raise ArgumentError, "argument pattern given twice"
        end
        o.each {|(o, *v)| pattern[o] = v.fetch(0) {o}}
      when Module
        raise ArgumentError, "unsupported argument type: #{o}"
      when *ArgumentStyle.keys
        style = notwice(ArgumentStyle[o], style, 'style')
      when /^--no-([^\[\]=\s]*)(.+)?/
        q, a = $1, $2
        o = notwice(a ? Object : TrueClass, klass, 'type')
        not_pattern, not_conv = search(:atype, o) unless not_style
        not_style = (not_style || default_style).guess(arg = a) if a
        default_style = Switch::NoArgument
        default_pattern, conv = search(:atype, FalseClass) unless default_pattern
        ldesc << "--no-#{q}"
        long << 'no-' + (q = q.downcase)
        nolong << q
      when /^--\[no-\]([^\[\]=\s]*)(.+)?/
        q, a = $1, $2
        o = notwice(a ? Object : TrueClass, klass, 'type')
        if a
          default_style = default_style.guess(arg = a)
          default_pattern, conv = search(:atype, o) unless default_pattern
        end
        ldesc << "--[no-]#{q}"
        long << (o = q.downcase)
        not_pattern, not_conv = search(:atype, FalseClass) unless not_style
        not_style = Switch::NoArgument
        nolong << 'no-' + o
      when /^--([^\[\]=\s]*)(.+)?/
        q, a = $1, $2
        if a
          o = notwice(NilClass, klass, 'type')
          default_style = default_style.guess(arg = a)
          default_pattern, conv = search(:atype, o) unless default_pattern
        end
        ldesc << "--#{q}"
        long << (o = q.downcase)
      when /^-(\[\^?\]?(?:[^\\\]]|\\.)*\])(.+)?/
        q, a = $1, $2
        o = notwice(Object, klass, 'type')
        if a
          default_style = default_style.guess(arg = a)
          default_pattern, conv = search(:atype, o) unless default_pattern
        end
        sdesc << "-#{q}"
        short << Regexp.new(q)
      when /^-(.)(.+)?/
        q, a = $1, $2
        if a
          o = notwice(NilClass, klass, 'type')
          default_style = default_style.guess(arg = a)
          default_pattern, conv = search(:atype, o) unless default_pattern
        end
        sdesc << "-#{q}"
        short << q
      when /^=/
        style = notwice(default_style.guess(arg = o), style, 'style')
        default_pattern, conv = search(:atype, Object) unless default_pattern
      else
        desc.push(o)
      end
    end

    default_pattern, conv = search(:atype, default_style.pattern) unless default_pattern
    s = if short.empty? and long.empty?
          raise ArgumentError, "no switch given" if style or pattern or block
          desc
        else
          (style || default_style).new(pattern || default_pattern,
                                       conv, sdesc, ldesc, arg, desc, block)
        end
    return s, short, long,
      (not_style.new(not_pattern, not_conv, sdesc, ldesc, nil, desc, block) if not_style),
      nolong
  end

=begin
--- OptionParser#on(*opts) [{...}]
--- OptionParser#def_option(*opts) [{...}]
--- OptionParser#on_head(*opts) [{...}]
--- OptionParser#def_head_option(*opts) [{...}]
--- OptionParser#on_tail(*opts) [{...}]
--- OptionParser#def_tail_option(*opts) [{...}]
    Defines option switch and handler. (({on_head})), (({def_head_option}))
    and (({on_tail})), (({def_tail_option})) put the switch at head
    and tail of summary, respectively.

    cf. ((<OptionParser#switch>)).
=end #'#"#`#
  def define(*opts, &block)
    top.append(*(sw = make_switch(*opts, &block)))
    sw[0]
  end
  def on(*opts, &block)
    define(*opts, &block)
    self
  end
  alias def_option define

  def define_head(*opts, &block)
    top.prepend(*(sw = make_switch(*opts, &block)))
    sw[0]
  end
  def on_head(*opts, &block)
    define_head(*opts, &block)
    self
  end
  alias def_head_option define_head

  def define_tail(*opts, &block)
    base.append(*(sw = make_switch(*opts, &block)))
    sw[0]
  end
  def on_tail(*opts, &block)
    define_tail(*opts, &block)
    self
  end
  alias def_tail_option define_tail

  def separator(string)
    top.append(string, nil, nil)
  end


=begin
--- OptionParser#order(*argv) [{...}]
--- OptionParser#order!([argv = ARGV]) [{...}]
    Parses ((|argv|)) in order. When non-option argument encountered,
    yields it if called as iterator, otherwise terminates the parse
    process.
    Returns rest of ((|argv|)) left unparsed.
    
    (({order!})) takes argument array itself, and removes switches
    destructively.
    Defaults to parse ((|ARGV|)).
    :Parameters:
      : ((|argv|))
        command line arguments to be parsed.
      : (({block}))
        called with each non-option argument.
=end #'#"#`#
  def order(*argv, &block)
    argv = argv[0].dup if argv.size == 1 and Array === argv[0]
    order!(argv, &block)
  end

  def order!(argv = ARGV, &nonopt)
    opt, arg, sw, val, rest = nil
    nonopt ||= proc {|arg| throw :terminate, arg}
    argv.unshift(arg) if arg = catch(:terminate) {
      while arg = argv.shift
        case arg
        # long option
        when /\A--([^=]*)(?:=(.*))?/
          opt, rest = $1, $2
          begin
            sw, = complete(:long, opt)
          rescue ParseError
            raise $!.set_option(arg, true)
          end
          begin
            opt, sw, val = sw.parse(rest, argv) {|*exc| raise(*exc)}
            sw.call(val) if sw
          rescue ParseError
            raise $!.set_option(arg, rest)
          end

        # short option
        when /\A-(.)((=).*|.+)?/
          opt, has_arg, eq, val, rest = $1, $3, $3, $2, $2
          begin
            unless sw = search(:short, opt)
              begin
                sw, = complete(:short, opt)
                # short option matched.
                val = arg.sub(/\A-/, '')
                has_arg = true
              rescue InvalidOption
                # if no short options match, try completion with long
                # options.
                sw, = complete(:long, opt)
                eq ||= !rest
              end
            end
          rescue ParseError
            raise $!.set_option(arg, true)
          end
          begin
            opt, sw, val = sw.parse(val, argv) {|*exc| raise(*exc) if eq}
            raise InvalidOption, arg if has_arg and !eq and arg == "-#{opt}"
            argv.unshift(opt) if opt and (opt = opt.sub(/\A-*/, '-')) != '-'
            sw.call(val) if sw
          rescue ParseError
            raise $!.set_option(arg, arg.length > 2)
          end

        # non-option argument
        else
          nonopt.call(arg)
        end
      end

      nil
    }

    argv
  end

=begin
--- OptionParser#permute(*argv)
--- OptionParser#permute!([argv = ARGV])
    Parses ((|argv|)) in permutation mode, and returns list of
    non-option arguments.
    
    (({permute!})) takes argument array itself, and removes switches
    destructively.
    Defaults to parse ((|ARGV|)).
    :Parameters:
      : ((|argv|))
        command line arguments to be parsed.
=end #'#"#`#
  def permute(*argv)
    argv = argv[0].dup if argv.size == 1 and Array === argv[0]
    permute!(argv)
  end

  def permute!(argv = ARGV)
    nonopts = []
    arg = nil
    order!(argv) {|arg| nonopts << arg}
    argv[0, 0] = nonopts
    argv
  end

=begin
--- OptionParser#parse(*argv)
--- OptionParser#parse!([argv = ARGV])
    Parses ((|argv|)) in order when environment variable (({POSIXLY_CORRECT}))
    is set, otherwise permutation mode
    
    (({parse!})) takes argument array itself, and removes switches
    destructively.
    Defaults to parse ((|ARGV|)).
    :Parameters:
      : ((|argv|))
        command line arguments to be parsed.
=end #'#"#`#
  def parse(*argv)
    argv = argv[0].dup if argv.size == 1 and Array === argv[0]
    parse!(argv)
  end

  def parse!(argv = ARGV)
    if ENV.include?('POSIXLY_CORRECT')
      order!(argv)
    else
      permute!(argv)
    end
  end


=begin private
--- OptionParser#visit(id, *args) {block}
    Traverses (({stack}))s calling method ((|id|)) with ((|*args|)).
    :Parameters:
      : ((|id|))
        called method in each elements of (({stack}))s.
      : ((|*args|))
        passed to ((|id|)).
      : (({block}))
        passed to ((|id|)).
=end #'#"#`#
  def visit(id, *args, &block)
    el = nil
    @stack.reverse_each do |el|
      el.send(id, *args, &block)
    end
    nil
  end
  private :visit

=begin private
--- OptionParser#search(id, k)
    Searches ((|k|)) in stack for ((|id|)) hash, and returns it or yielded
    value if called as iterator.
    :Parameters:
      : ((|id|))
        searching table.
      : ((|k|))
        searching key.
      : (({block}))
        yielded with the found value when succeeded.
=end #'#"#`#
  def search(id, k)
    visit(:search, id, k) do |k|
      return k unless block_given?
      return yield(k)
    end
  end
  private :search

=begin private
--- OptionParser#complete(typ, opt, *etc)
    Completes shortened long style option switch, and returns pair of
    canonical switch and switch descriptor((<OptionParser::Switch>)).
    :Parameters:
      : ((|id|))
        searching table.
      : ((|opt|))
        searching key.
      : ((|*pat|))
        optional pattern for completion.
      : (({block}))
        yielded with the found value when succeeded.
=end #'#"#`#
  def complete(typ, opt, *pat)
    if pat.empty?
      search(typ, opt) {|sw| return [sw, opt]} # exact match or...
    end
    raise AmbiguousOption, catch(:ambiguous) {
      visit(:complete, typ, opt, *pat) {|opt, *sw| return sw}
      raise InvalidOption, opt
    }
  end
  private :complete

=begin undocumented
--- OptionParser#load([filename])
    Loads options from file named as ((|filename|)). Does nothing when
    the file is not present. Returns whether successfuly loaded.
    :Parameters:
      : ((|filename|))
        option file name.  defaulted to basename of the program without
        suffix in a directory ((%~/.options%)).
=end #'#"#`#
  def load(filename = nil)
    begin
      filename ||= File.expand_path(File.basename($0, '.*'), '~/.options')
    rescue
      return false
    end
    begin
      parse(*IO.readlines(filename).each {|s| s.chomp!})
      true
    rescue Errno::ENOENT, Errno::ENOTDIR
      false
    end
  end

=begin undocumented
--- OptionParser#environment([env])
    Parses environment variable ((|env|)) or its uppercase with spliting
    like as shell.
    :Parameters:
      : ((|env|))
        defaulted to basename of the program.
=end #'#"#`#
  def environment(env = File.basename($0, '.*'))
    env = ENV[env] || ENV[env.upcase] or return
    parse(*Shellwords.shellwords(env))
  end


=begin
= Acceptable argument classes
=end #'#"#`#

=begin
: Object
  any string, and no conversion. this is fall-back.
=end #'#"#`#
  accept(Object) {|s,|s or s.nil?}

  accept(NilClass) {|s,|s}

=begin
: String
  any none-empty string, and no conversion.
=end #'#"#`#
  accept(String, /.+/) {|s,*|s}

=begin
: Integer
  Ruby/C-like integer, octal for (({0-7})) sequence, binary for
  (({0b})), hexadecimal for (({0x})), and decimal for others; with
  optional sign prefix. Converts to (({Integer})).
=end #'#"#`#
  decimal = '\d+(?:_\d+)*'
  binary = 'b[01]+(?:_[01]+)*'
  hex = 'x[\da-f]+(?:_[\da-f]+)*'
  octal = "0(?:[0-7]*(?:_[0-7]+)*|#{binary}|#{hex})"
  integer = "#{octal}|#{decimal}"
  accept(Integer, %r"\A[-+]?(?:#{integer})"io) {|s,| Integer(s) if s}

=begin
: Float
  Float number format, and converts to (({Float})).
=end #'#"#`#
  float = "(?:#{decimal}(?:\\.(?:#{decimal})?)?|\\.#{decimal})(?:E[-+]?#{decimal})?"
  floatpat = %r"\A[-+]?#{float}"io
  accept(Float, floatpat) {|s,| s.to_f if s}

=begin
: Numeric
  Generic numeric format, and converts to (({Integer})) for integer
  format, (({Float})) for float format.
=end #'#"#`#
  accept(Numeric, %r"\A[-+]?(?:#{octal}|#{float})"io) {|s,| eval(s) if s}

=begin
: OptionParser::DecimalInteger
  Decimal integer format, to be converted to (({Integer})).
=end #'#"#`#
  DecimalInteger = /\A[-+]?#{decimal}/io
  accept(DecimalInteger) {|s,| s.to_i if s}

=begin
: OptionParser::OctalInteger
  Ruby/C like octal/hexadecimal/binary integer format, to be converted
  to (({Integer})).
=end #'#"#`#
  OctalInteger = /\A[-+]?(?:[0-7]+(?:_[0-7]+)*|0(?:#{binary}|#{hex}))/io
  accept(OctalInteger) {|s,| s.oct if s}

=begin
: OptionParser::DecimalNumeric
  Decimal integer/float number format, to be converted to
  (({Integer})) for integer format, (({Float})) for float format.
=end #'#"#`#
  DecimalNumeric = floatpat     # decimal integer is allowed as float also.
  accept(DecimalNumeric) {|s,| eval(s) if s}

=begin
: TrueClass
  Boolean switch, which means whether it is present or not, whether it
  is absent or not with prefix (({no-})), or it takes an argument
  (({yes/no/true/false/+/-})).
: FalseClass
  Similar to ((<TrueClass>)), but defaulted to (({false})).
=end #'#"#`#
  yesno = CompletingHash.new
  %w[- no false].each {|el| yesno[el] = false}
  %w[+ yes true].each {|el| yesno[el] = true}
  yesno['nil'] = false          # shoud be nil?
  accept(TrueClass, yesno) {|arg, val| val == nil or val}
  accept(FalseClass, yesno) {|arg, val| val != nil and val}

=begin
: Array
  List of strings separated by ","
=end #'#"#`#
  accept(Array) do |s,|
    if s
      s = s.split(',').collect {|s| s unless s.empty?}
    end
    s
  end


=begin
= Exceptions
=end #'#"#`#

=begin
== ((:OptionParser::ParseError:))
Base class of exceptions from ((<OptionParser>))
=== Superclass
(({RuntimeError}))
=== Constants
: OptionParser::ParseError::Reason
  Reason caused error.
=== Instance methods
--- OptionParser::ParseError#recover(argv)
    Push backs erred argument(s) to ((|argv|)).
--- OptionParser::ParseError#reason
    Returns error reason. Override this to I18N.
--- OptionParser::ParseError#inspect
    Returns inspection string.
--- OptionParser::ParseError#message
--- OptionParser::ParseError#to_s
--- OptionParser::ParseError#to_str
    Default stringizing method to emit standard error message.
=end #'#"#`#
  class ParseError < RuntimeError
    Reason = 'parse error'.freeze

    def initialize(*args)
      @args = args
      @reason = nil
    end

    attr_reader :args
    attr_writer :reason

    def recover(argv)
      argv[0, 0] = @args
      argv
    end

    def set_option(opt, eq)
      if eq
        @args[0] = opt
      else
        @args.unshift(opt)
      end
      self
    end

    def reason
      @reason || self.class::Reason
    end

    def inspect
      "#<#{self.class.to_s}: #{args.join(' ')}>"
    end

    def message
      reason + ': ' + args.join(' ')
    end

    alias to_s message
    alias to_str message
  end

=begin
== ((:OptionParser::AmbiguousOption:))
Raises when encountered ambiguously completable string.
=== Superclass
((<OptionParser::ParseError>))
=end #'#"#`#
  class AmbiguousOption < ParseError
    const_set(:Reason, 'ambiguous option'.freeze)
  end

=begin
== ((:OptionParser::NeedlessArgument:))
Raises when encountered argument for switch defined as which takes no
argument.
=== Superclass
((<OptionParser::ParseError>))
=end #'#"#`#
  class NeedlessArgument < ParseError
    const_set(:Reason, 'needles argument'.freeze)
  end

=begin
== ((:OptionParser::MissingArgument:))
Raises when no argument found for switch defined as which needs
argument.
=== Superclass
((<OptionParser::ParseError>))
=end #'#"#`#
  class MissingArgument < ParseError
    const_set(:Reason, 'missing argument'.freeze)
  end

=begin
== ((:OptionParser::InvalidOption:))
Raises when undefined switch.
=== Superclass
((<OptionParser::ParseError>))
=end #'#"#`#
  class InvalidOption < ParseError
    const_set(:Reason, 'invalid option'.freeze)
  end

=begin
== ((:OptionParser::InvalidArgument:))
Raises when the given argument does not match required format.
=== Superclass
((<OptionParser::ParseError>))
=end #'#"#`#
  class InvalidArgument < ParseError
    const_set(:Reason, 'invalid argument'.freeze)
  end

=begin
== ((:OptionParser::AmbiguousArgument:))
Raises when the given argument word can't completed uniquely.
=== Superclass
((<OptionParser::InvalidArgument>))
=end #'#"#`#
  class AmbiguousArgument < InvalidArgument
    const_set(:Reason, 'ambiguous argument'.freeze)
  end


=begin
= Miscellaneous
=end #'#"#`#
=begin
== ((:OptionParser::Arguable:))
Extends command line arguments array to parse itself.
=end #'#"#`#
  module Arguable
=begin
--- OptionParser::Arguable#options=(opt)
    Sets ((<OptionParser>)) object, when ((|opt|)) is (({false})) or
    (({nil})), methods ((<OptionParser::Arguable#options>)) and
    ((<OptionParser::Arguable#options=>)) are undefined.  Thus, there
    is no ways to access the ((<OptionParser>)) object via the
    receiver object.
=end #'#"#`#
    def options=(opt)
      unless @optparse = opt
        class << self
          undef_method(:options)
          undef_method(:options=)
        end
      end
    end

=begin
--- OptionParser::Arguable#options
    Actual ((<OptionParser>)) object, automatically created if not
    yet.

    If called as iterator, yields with the ((<OptionParser>)) object
    and returns the result of the block. In this case, rescues any
    ((<OptionParser::ParseError>)) exceptions in the block, just emits
    error message to ((<STDERR>)) and returns (({nil})).

    :Parameters:
      : (({block}))
        Yielded with the ((<OptionParser>)) instance.

=end #'#"#`#
    def options
      @optparse ||= OptionParser.new
      block_given? or return @optparse
      begin
        yield @optparse
      rescue ParseError
        @optparse.warn $!
        nil
      end
    end

=begin
--- OptionParser::Arguable#order!
--- OptionParser::Arguable#permute!
--- OptionParser::Arguable#parse!
    Parses ((|self|)) destructively, and returns ((|self|)) just contains
    rest arguments left without parsed.
=end #'#"#`#
    def order!(&blk) options.order!(self, &blk) end
    def permute!() options.permute!(self) end
    def parse!() options.parse!(self) end

=begin private
Initializes instance variable.
=end #'#"#`#
    def self.extend_object(obj)
      super
      obj.instance_eval {@optparse = nil}
    end
    def initialize(*args)
      super
      @optparse = nil
    end
  end

=begin
== OptionParser::Acceptables
Acceptable argument classes.  Now contains (({DecimalInteger})),
(({OctalInteger})) and (({DecimalNumeric})).
see ((<Acceptable argument classes>)).
=end #'#"#`#
  module Acceptables
    const_set(:DecimalInteger, OptionParser::DecimalInteger)
    const_set(:OctalInteger, OptionParser::OctalInteger)
    const_set(:DecimalNumeric, OptionParser::DecimalNumeric)
  end
end

# ARGV is arguable by OptionParser
ARGV.extend(OptionParser::Arguable)


if $0 == __FILE__
  Version = OptionParser::Version
  ARGV.options {|q|
    q.parse!.empty? or puts "what's #{ARGV.join(' ')}?"
  } or exit 1
end
__END__
=begin example
= Example
<<< opttest.rb
=end #'#"#`#