File: Generic.pm

package info (click to toggle)
libfinance-quotehist-perl 1.24-2
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 436 kB
  • ctags: 206
  • sloc: perl: 1,481; makefile: 4
file content (1607 lines) | stat: -rw-r--r-- 48,938 bytes parent folder | download
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
package Finance::QuoteHist::Generic;

# http://www.stanford.edu/dept/OOD/RESEARCH/top-ten-faq/how_do_i_find_an_historical_st.html
#
# Shortcut: Use adjusted close price
#
# For the mathematically inclined, one shortcut to determining the value
# after splits is to use the adjusted close price from the historical
# quote tool. For June 2, 1997, it lists a market close price of 33.13
# and an adjusted close price of 1.38. Divide 33.13 by 1.38 and you come
# up with 24.007. Multiply by 1,000 and you come pretty close to the
# 24,000 share figure determined above. Or you could divide 1.38 by
# 33.13, which gives you 0.041654. Divide $33,130 by 0.041654, and you
# get $795K, which is very close to the $808K figure above.

use strict;
use Carp;

use LWP::UserAgent;
use HTTP::Request;
use Date::Manip;

use vars qw($VERSION);

$VERSION = '1.21';

my $CSV_XS_Class = 'Text::CSV_XS';
my $CSV_PP_Class = 'Text::CSV_PP';
my $CSV_Class = $CSV_XS_Class;
eval "use $CSV_Class";
if ($@) {
  $CSV_Class = $CSV_PP_Class;
  eval "use $CSV_Class";
  croak "Could not load either $CSV_XS_Class or $CSV_PP_Class : $@\n" if $@;
}

my $HTE_CLASS;
my $HTE_Class = 'HTML::TableExtract';
sub HTML_CLASS {
  if (!$HTE_CLASS) {
    eval "use $HTE_Class";
    croak $@ if $@;
    $HTE_CLASS = $HTE_Class;
  }
  $HTE_CLASS;
}

my $Default_Target_Mode = 'quote';
my $Default_Parse_Mode  = 'html';
my $Default_Granularity = 'daily';
my $Default_Vol_Pat = qr(vol|shares)i;

my %Default_Labels;
$Default_Labels{quote}{$Default_Parse_Mode} =
  [qw( date open high low close ), $Default_Vol_Pat];
$Default_Labels{dividend}{$Default_Parse_Mode} =
  [qw( date div )];
$Default_Labels{'split'}{$Default_Parse_Mode} =
  [qw( date post pre )];
$Default_Labels{intraday}{$Default_Parse_Mode} =
  [qw( date time high low close ), $Default_Vol_Pat];

my @Scalar_Flags = qw(
  verbose
  quiet
  zthresh
  quote_precision
  attempts
  adjusted
  has_non_adjusted
  env_proxy
  debug
  parse_mode
  target_mode
  granularity
  auto_proxy
  row_filter
);
my $SF_pat = join('|', @Scalar_Flags);

my @Array_Flags = qw(
  symbols
  lineup
);
my $AF_pat = join('|', @Array_Flags);

my @Hash_Flags = qw( ua_params );
my $HF_pat = join('|', @Hash_Flags);

sub new {
  my $that  = shift;
  my $class = ref($that) || $that;
  my(@pass, %parms, $k, $v);
  while (($k,$v) = splice(@_, 0, 2)) {
    if ($k eq 'start_date' || $k eq 'end_date' && $v !~ /^\s*$/) {
      $parms{$k} = __PACKAGE__->date_standardize($v);
    }
    elsif ($k =~ /^$AF_pat$/o) {
      if (UNIVERSAL::isa($v, 'ARRAY')) {
        $parms{$k} = $v;
      }
      elsif (ref $v) {
        croak "$k must be passed as an array ref or single-entry string\n";
      }
      else {
        $parms{$k} = [$v];
      }
    }
    elsif ($k =~ /^$HF_pat$/o) {
      if (UNIVERSAL::isa($v, 'HASH')) {
        $parms{$k} = $v;
      }
      else {
        croak "$k must be passed as a hash ref\n";
      }
    }
    elsif ($k eq 'row_filter') {
      croak "$k must be sub ref\n" unless UNIVERSAL::isa($v, 'CODE');
      $parms{$k} = $v;
    }
    elsif ($k =~ /^$SF_pat$/o) {
      $parms{$k} = $v;
    }
  }
  $parms{end_date} ||= __PACKAGE__->date_standardize('today');
  $parms{symbols} or croak "Symbol list required\n";

  my $start_date = delete $parms{start_date};
  my $end_date   = delete $parms{end_date};
  my $symbols    = delete $parms{symbols};

  # Defaults
  $parms{zthresh}          = 30 unless $parms{zthresh};
  $parms{attempts}         = 3  unless $parms{attempts};
  $parms{adjusted}         = 1  unless exists  $parms{adjusted};
  $parms{has_non_adjusted} = 0  unless defined $parms{has_non_adjusted};
  $parms{quote_precision}  = 4  unless defined $parms{quote_precision};
  $parms{auto_proxy}       = 1  unless exists  $parms{auto_proxy};
  $parms{debug}            = 0  unless defined $parms{debug};

  my $self = \%parms;
  bless $self, $class;

  my $ua_params = $parms{ua_params} || {};
  if ($parms{env_proxy}) {
    $ua_params->{env_proxy} = 1;
  }
  elsif ($parms{auto_proxy}) {
    $ua_params->{env_proxy} = 1 if $ENV{http_proxy};
  }
  delete $parms{env_proxy};
  $self->{ua} = LWP::UserAgent->new(%$ua_params);

  if ($self->granularity !~ /^d/i) {
    $start_date = $self->snap_start_date($start_date);
    $end_date   = $self->snap_end_date($end_date);
  }

  $self->start_date($start_date);
  $self->end_date($end_date);
  $self->symbols(@$symbols);

  # These are used for constructing method names for target types.
  $self->{target_order} = [qw(quote split dividend)];
  grep($self->{targets}{$_} = "${_}s", @{$self->{target_order}});

  $self;
}

### User interface stubs

sub quotes    { shift->getter(target_mode => 'quote')->()    }
sub dividends { shift->getter(target_mode => 'dividend')->() }
sub splits    { shift->getter(target_mode => 'split')->()    }
sub intraday  { shift->getter(target_mode => 'intraday')->() }

*intraday_quotes = *intraday;

sub target_worthy {
  my $self = shift;
  my %parms = @_;
  my $target_mode = $parms{target_mode} || $self->target_mode;
  my $parse_mode  = $parms{parse_mode}  || $self->parse_mode;
  # forcing url_maker into a boolean role here, using a dummy symbol
  my $capable = $self->url_maker(
    %parms,
    target_mode => $target_mode,
    parse_mode  => $parse_mode,
    symbol      => 'waggledance',
  );
  my $worthy = $capable && UNIVERSAL::isa($capable, 'CODE');
  if ($self->{verbose}) {
    print STDERR "Seeing if ", ref $self,
                 " can get ($target_mode, $parse_mode) : ",
                 $worthy ? "yes\n" : "no\n";
  }
  $worthy;
}

sub granularities { qw( daily ) }

### Data retrieval

sub ua {
  my $self = shift;
  @_ ? $self->{ua} = shift : $self->{ua};
}

sub fetch {
  # HTTP::Request and LWP::UserAgent Wrangler
  my($self, $request) = splice(@_, 0, 2);
  $request or croak "Request or URL required\n";

  if (! ref $request || ! $request->isa('HTTP::Request')) {
    $request = HTTP::Request->new(GET => $request);
  }

  my $trys = $self->{attempts};
  my $response = $self->ua->request($request, @_);
  $self->{_lwp_success} = 0;
  while (! $response->is_success) {
    last unless $trys;
    $self->{_lwp_status}  = $response->status_line;
    print STDERR "Bad fetch",
       $response->is_error ? ' (' . $response->status_line . '), ' : ', ',
       "trying again...\n" if $self->{debug};
    $response = $self->ua->request($request, @_);
    --$trys;
  }
  $self->{_lwp_success} = $response->is_success;
  return undef unless $response->is_success;
  print STDERR 'Fetch complete. (' . length($response->content) . " chars)\n"
    if $self->{verbose};
  $response->content;
}

sub getter {
  # closure factory to get results for a particular target_mode and
  # parse_mode
  my $self = shift;

  my %parms = @_;
  my $target_mode = $parms{target_mode} || $self->target_mode;
  my $parse_mode  = $parms{parse_mode}  || $self->parse_mode;
  my @column_labels = $self->labels(
    %parms, target_mode => $target_mode, parse_mode  => $parse_mode
  );
  my %extractors = $self->extractors(
    %parms, target_mode => $target_mode, parse_mode  => $parse_mode
  );

  # return our closure
  sub {
    my @symbols = @_ ? @_ : $self->symbols;

    my @rows;

    # cache check
    my @not_seen;
    foreach my $symbol (@symbols) {
      my @r = $self->result_rows($target_mode, $symbol);
      if (@r) {
        push(@rows, @r);
      }
      else {
        push(@not_seen, $symbol);
      }
    }
    return @rows unless @not_seen;

    my $original_target_mode = $self->target_mode;
    my $original_parse_mode  = $self->parse_mode;

    $self->target_mode($target_mode);
    $self->parse_mode($parse_mode);

    my $dcol = $self->label_column('date');
    my(%empty_fetch, %saw_good_rows);
    my $last_data = '';

    my $target_worthy = $self->target_worthy(
      %parms,
      target_mode => $target_mode,
      parse_mode  => $parse_mode
    );
    if (!$target_worthy) {
      # make sure and empty @symbols
      ++$empty_fetch{$_} while $_ = pop @symbols;
    }

    SYMBOL: foreach my $s (@symbols) {
      my $urlmaker = $self->url_maker(
        target_mode => $target_mode,
        parse_mode  => $parse_mode,
        symbol      => $s,
      );
      UNIVERSAL::isa($urlmaker, 'CODE') or croak "urlmaker not a code ref.\n";
      my $so_far_so_good = 0;
      URL: while (my $url = $urlmaker->()) {
        if ($empty_fetch{$s}) {
          print STDERR ref $self,
             " passing on $s ($target_mode) for now, empty fetch\n"
             if $self->{verbose};
          last URL;
        }

        if ($self->{verbose}) {
          my $uri = $url;
          $uri = $url->uri if UNIVERSAL::isa($url, 'HTTP::Request');
          print STDERR "Processing ($s:$target_mode) $uri\n";
        }

        # We're a bit more persistent with quotes. It is more suspicious
        # if we get no quote rows, but it is nevertheless possible.
        my $trys = $target_mode eq 'quote' ? $self->{attempts} : 1;
        my $initial_trys = $trys;
        my($data, $rows) = ('', []);
        do {
          print STDERR "$s Trying ($target_mode) again due to no rows...\n"
            if $self->{verbose} && $trys != $initial_trys;
          if (!($data = $self->{url_cache}{$url})) {
            $data = $self->fetch($url);
            if (my $pre_parser = $self->pre_parser) {
              $data = $pre_parser->(
                $data,
                target_mode => $target_mode,
                parse_mode  => $parse_mode,
              );
            }
          }
          # make sure our url_maker hasn't sent us into a twister
          if ($data && $data eq $last_data) {
            print STDERR "Redundant data fetch, assuming end of URLs.\n"
              if $self->{verbose};
            last URL;
          }
          else {
            $last_data = defined $data ? $data : '';
          }
          $rows = $self->rows($self->parser->($data));
          last URL if $so_far_so_good && !@$rows;
          --$trys;
        } while !@$rows && $trys && $self->{_lwp_success};
        $so_far_so_good = 1;

        if ($target_mode ne 'quote' || $target_mode ne 'intraday') {
          # We are not very stubborn about dividends and splits right
          # now. This is because we cannot prove a successful negative
          # (i.e., say there were no dividends or splits over the time
          # period...or perhaps there were, but it is a defunct
          # symbol...whatever...quotes should always be present unless
          # they are defunct, which is dealt with later.
          if (!$self->{_lwp_success} || !$data) {
            ++$empty_fetch{$s};
            @$rows = ();
          }
          elsif ($self->{_lwp_success} && !@$rows) {
            ++$empty_fetch{$s};
          }
        }

        # Raw cache
        $self->{url_cache}{$url} = $data;
  
        # Extraction filters. This is an opportunity to extract rows
        # that are not what we are looking for, but contain valuable
        # information nevertheless. An example of this would be the
        # split and dividend rows you see in Yahoo HTML quote output. An
        # extraction filter method should expect an array ref as an
        # argument, representing a single row, and should return another
        # array ref with extracted output. If there is a return value,
        # then this row will be filtered from the primary output.
        my(%extractions, $ecount, $rc);
        $rc = @$rows;
        if (%extractors) {
          my(@filtered, $row);
          while ($row = pop(@$rows)) {
            my $erow;
            foreach my $mode (sort keys %extractors) {
              $extractions{$mode} ||= [];
              my $em = $extractors{$mode};
              if ($erow = $em->($row)) {
                print STDERR "$s extract ($mode) got $s, ",
                   join(', ', @$erow), "\n" if $self->{verbose};
                push(@{$extractions{$mode}}, [@$erow]);
                ++$ecount;
                last;
              }
            }
            push(@filtered, $row) unless $erow;
          }
          if ($self->{verbose} && $ecount) {
            print STDERR "$s Trimmed to ",$rc - $ecount,
               " rows after $ecount extractions.\n";
          }
          $rows = \@filtered;
        }

        if ($extractions{$target_mode}) {
          $rows = [@{$extractions{$target_mode}}];
          print STDERR "Coopted to ", scalar @$rows,
            " rows after $target_mode extraction redundancy.\n"
            if $self->{verbose};
        }

        if (@$rows) {
          # Normalization steps

          if ($target_mode eq 'split') {
            if (@{$rows->[0]} == 2) {
              foreach (@$rows) {
                if ($_->[-1] =~ /split\s+(\d+):(\d+)/is) {
                  splice(@$_, -1, 1, $1, $2);
                }
              }
            }
          }

          # Saving the rounding operations until after the adjust
          # routine is deliberate since we don't want to be auto-
          # adjusting pre-rounded numbers.
          $self->number_normalize_rows($rows);
  
          # Do the same for the extraction rows, plus store the
          # extracted rows
          foreach my $mode (keys %extractions) {
            # _store_results splices each row...don't do it twice
            next if $mode eq $target_mode;
            $self->target_mode($mode);
            $self->number_normalize_rows($extractions{$mode});
            $self->_target_source($mode, $s, ref $self);
            $self->_store_results($mode, $s, $dcol, $extractions{$mode});
          }
          # restore original target mode
          $self->target_mode($target_mode);
  
          if ($target_mode eq 'quote' || $target_mode eq 'intraday') {
            my $count = @$rows;
            @$rows = grep($self->is_quote_row($_) &&
                          $self->row_not_seen($s, $_), @$rows);
            if ($self->{verbose}) {
              if ($count == @$rows) {
                print STDERR "$s Retained $count rows\n";
              }
              else {
                print STDERR "$s Retained $count raw rows, trimmed to ",
                  scalar @$rows, " rows due to noise\n";
              }
            }
  
          }
          if ($target_mode eq 'quote') {
            # zcount is an attempt to capture null values; if there are
            # too many we assume there is something wrong with the
            # remote data
            my $close_col = $self->label_column('close');
            my($zcount, $hcount) = (0,0);
            foreach (@$rows) {
              foreach (@$_) {
                # Sometimes N/A appears
                s%^\s*N/A\s*$%%;
              }
              my $q = $_->[$close_col];
              if (defined $q && $q =~ /\d+/) { ++$hcount }
              else                            { ++$zcount }
            }
            my $pct = $hcount ? 100 * $zcount / ($zcount + $hcount) : 100;
            if (!$trys || $pct >= $self->{zthresh}) {
              ++$empty_fetch{$s} unless $saw_good_rows{$s};
            }
            else {
              # For defunct symbols, we could conceivably get quotes
              # over a date range that contains blocks of time where the
              # ticker was actively traded, as well as blocks of time
              # where the ticker doesn't exist. If we got good data over
              # some of the blocks, then we take note of it so we don't
              # toss the whole set of queries for this symbol.
              ++$saw_good_rows{$s};
            }
            $self->precision_normalize_rows($rows)
              if @$rows && $self->{quote_precision};
          }

          last URL if !$ecount && !@$rows;
          $self->_store_results($target_mode, $s, $dcol, $rows) if @$rows;
          $self->_target_source($target_mode, $s, ref $self);
        }
      }
    }

    $self->_store_empty_fetches([keys %empty_fetch]);
  
    # Check for bad fetches. If we failed on some symbols, punt them to
    # our champion class.
    if (%empty_fetch) {
      my @bad_symbols = $self->empty_fetches;
      my @champion_classes = $self->lineup;
      while (@champion_classes && @bad_symbols) {
        print STDERR "Bad fetch for ", join(',', @bad_symbols), "\n"
          if $self->{verbose} && $target_worthy;
        my $champion =
          $self->_summon_champion(shift @champion_classes, @bad_symbols);
        next unless $champion &&
                    $champion->target_worthy(target_mode => $target_mode);
        print STDERR ref $champion, ", my hero!\n" if $self->{verbose};
        # Hail Mary
        $champion->getter(target_mode => $target_mode)->();
        # Our champion was the source for these symbols (including
        # extracted info).
        foreach my $mode ($champion->result_modes) {
          foreach my $symbol ($champion->result_symbols($mode)) {
            $self->_target_source($mode, $symbol, ref $champion);
            $self->_copy_results($mode, $symbol,
                                 $champion->results($mode, $symbol));
          }
        }
        @bad_symbols = $champion->empty_fetches;
      }
      if (@bad_symbols && !$self->{quiet}) {
        print STDERR "WARNING: Could not fetch $target_mode for some symbols (",join(', ', @bad_symbols), "). Abandoning request for these symbols.";
        if ($target_mode ne 'quote') {
          print STDERR " Don't worry, though, we were looking for ${target_mode}s. These are less likely to exist compared to quotes.";
        }
        if ($self->{_lwp_status}) {
          print STDERR "\n\nLast status: $self->{_lwp_status}\n";
        }
        print STDERR "\n";
      }
    }
  
    $self->target_mode($original_target_mode);
    $self->parse_mode($original_parse_mode);

    @rows = $self->result_rows($target_mode);
    if ($self->{verbose}) {
      print STDERR "Class ", ref $self, " returning ", scalar @rows,
         " composite rows.\n";
    }

    # Return the loot.
    wantarray ? @rows : \@rows;
  };
}

sub _store_results {
  my($self, $mode, $symbol, $dcol, $rows) = @_;
  foreach my $row (@$rows) {
    my $date = splice(@$row, $dcol, 1);
    $self->{results}{$mode}{$symbol}{$date} = $row;
  }
}

sub _copy_results {
  my($self, $mode, $symbol, $results) = @_;
  foreach my $date (sort keys %$results) {
    $self->{results}{$mode}{$symbol}{$date} = [@{$results->{$date}}];
  }
}

sub result_rows {
  my($self, $target_mode, @symbols) = @_;
  $target_mode ||= $self->target_mode;
  @symbols = $self->result_symbols($target_mode) unless @symbols;
  my @rows;
  foreach my $symbol (@symbols) {
    my $results = $self->results($target_mode, $symbol);
    foreach my $date (sort keys %$results) {
      push(@rows, [$symbol, $date, @{$results->{$date}}]);
    }
  }
  sort { $a->[1] cmp $b->[1] } @rows;
}

sub _store_empty_fetches {
  my $self = shift;
  my $ref = shift || [];
  @$ref = sort @$ref;
  $self->{empty_fetches} = $ref;
}

sub empty_fetches {
  my $self = shift;
  return () unless $self->{empty_fetches};
  @{$self->{empty_fetches}} 
}

sub extractors { () }

sub rows {
  my($self, $rows) = @_;
  return wantarray ? () : [] unless $rows;
  my $rc = @$rows;
  print STDERR "Got $rc raw rows\n" if $self->{verbose};

  # Load user filter if present
  my $row_filter = $self->row_filter;

  # Prep the rows
  foreach my $row (@$rows) {
    $row_filter->($row) if $row_filter;
    foreach (@$row) {
      # Zap leading and trailing white space
      next unless defined;
      s/^\s+//; s/\s+$//;
    }
  }
  # Pass only rows with a valid date that is in range (and store the
  # processed value while we are at it)
  my $target_mode = $self->target_mode;
  my @date_rows;
  my $dcol = $self->label_column('date');
  my $tcol = $self->label_column('time') if $target_mode eq 'intraday';
  my $r;
  while($r = pop @$rows) {
    my $date = $r->[$dcol];
    if ($target_mode eq 'intraday') {
      my $time = splice(@$r, $tcol, 1);
      $date = join('', $date, $time);
    }
    $date = $self->date_normalize($date);
    unless ($date) {
      print STDERR "Reject row (no date): '$r->[$dcol]'\n" if $self->{verbose};
      next;
    }
    next unless $self->date_in_range($date);
    $r->[$dcol] = $date;
    push(@date_rows, $r);
  }

  print STDERR "Trimmed to ", scalar @date_rows, " applicable date rows\n"
    if $self->{verbose} && @date_rows != $rc;

  return wantarray ? @date_rows : \@date_rows;
}

### Adjustment triggers and manipulation

sub adjuster {
  # In order to be an adjuster, it must first be enabled. In addition,
  # there has to be a column specified as the adjusted value. This is
  # not as generic as I would like it, but so far it's just for
  # Yahoo...it should work for any site with "adj" in the column
  # label...this column should be the adjusted closing value.
  my $self = shift;
  return 0 if !$self->{adjusted};
  foreach ($self->labels) {
    return 1 if /adj/i;
  }
  0;
}

sub adjusted { shift->{adjusted} ? 1 : 0 }

### Bulk manipulation filters

sub date_normalize_rows {
  # Place dates into a consistent format, courtesy of Date::Manip
  my($self, $rows, $dcol) = @_;
  $dcol = $self->label_column('date') unless defined $dcol;
  foreach my $row (@$rows) {
    $row->[$dcol] = $self->date_normalize($row->[$dcol]);
  }
  $rows;
}

sub date_normalize {
  my($self, $date) = @_;
  return unless $date;
  my $normal_date;
  if ($self->granularity =~ /^m/ && $date =~ m{^\s*(\D+)[-/]+(\d{2,})\s*$}) {
    my($m, $y) = ($1, $2);
    $y += 1900 if length $y == 2;
    $normal_date = ParseDate($m =~ /^\d+$/ ? "$y/$m/01" : "$m 01 $y");
  }
  else {
    $normal_date = ParseDate($date);
  }
  $normal_date or return undef;
  return $normal_date if $self->target_mode eq 'intraday';
  join('/', $self->ymd($normal_date));
}

sub snap_start_date {
  my($self, $date) = @_;
  my $g = $self->granularity;
  if ($g =~ /^(m|w)/i) {
    if ($1 eq 'm') {
      my($dom) = UnixDate($date, '%d') - 1;
      $date = DateCalc($date, "- $dom days") if $dom;
    }
    else {
      my $dow = Date_DayOfWeek(UnixDate($date, '%m', '%d', '%Y')) - 1;
      $date = DateCalc($date, "- $dow days") if $dow;
    }
  }
  $date;
}

sub snap_end_date {
  my($self, $date) = @_;
  my $g = $self->granularity;
  if ($g =~ /^(m|w)/i) {
    if ($1 eq 'm') {
      my($m, $y) = UnixDate($date, '%m', '%Y');
      my $last = Date_DaysInMonth($m, $y);
      $date = ParseDateString("$y$m$last");
    }
    else {
      my $dow = Date_DayOfWeek(UnixDate($date, '%m', '%d', '%Y')) - 1;
      $date = DateCalc($date, "+ " . (6 - $dow) . ' days')
        unless $dow == 6;
    }
  }
  $date;
}

sub number_normalize_rows {
  # Strip non-numeric noise from numeric fields
  my($self, $rows, $dcol) = @_;
  $dcol = $self->label_column('date') unless defined $dcol;
  # filtered rows might not have same columns
  my @cols = grep($_ != $dcol, 0 .. $#{$rows->[0]});
  foreach my $row (@$rows) {
    s/[^\d\.]//go foreach @{$row}[@cols];
  }
  $rows;
}

sub precision_normalize_rows {
  # Round off numeric fields, if requested (%.4f by default). Volume
  # is the exception -- we just round that into an integer. This
  # should probably only be called for 'quote' targets because it
  # knows details about where the numbers of interest reside.
  my($self, $rows) = @_;
  my $target_mode = $self->target_mode;
  croak "precision_normalize invoked in '$target_mode' mode rather than 'quote'  or 'intraday' mode.\n"
    unless $target_mode eq 'quote' || $target_mode eq 'intraday';
  my @columns;
  if ($target_mode ne 'intraday') {
    @columns = $self->label_column(qw(open high low close));
    push(@columns, $self->label_column('adj')) if $self->adjuster;
  }
  else {
    @columns = $self->label_column(qw(high low close));
  }
  my $vol_col = $self->label_column($Default_Vol_Pat);
  foreach my $row (@$rows) {
    $row->[$_] = sprintf("%.$self->{quote_precision}f", $row->[$_])
      foreach @columns;
    $row->[$vol_col] = int $row->[$vol_col];
  }
  $rows;
}

### Single row filters

sub is_quote_row {
  my($self, $row, $dcol) = @_;
  ref $row or croak "Row ref required\n";
  # Skip date in first field
  $dcol = $self->label_column('date') unless defined $dcol;
  foreach (0 .. $#$row) {
    next if $_ == $dcol;
    next if $row->[$_] =~ /^\s*$/;
    if ($row->[$_] !~ /^\s*\$*[\d\.,]+\s*$/) {
      return 0;
    }
  }
  1;
}

sub row_not_seen {
  my($self, $symbol, $row, $dcol) = @_;
  ref $row or croak "Row ref required\n";
  $symbol or croak "ticker symbol required\n";
  my $mode = $self->target_mode;
  my $res = $self->{results}{$mode} or return 1;
  my $mres = $res->{$symbol} or return 1;
  $dcol = $self->label_column('date') unless defined $dcol;
  $mres->{$row->[$dcol]} or return 1;
  return 0;
}

sub date_in_range {
  my $self = shift;
  my $date = shift;
  $date = $self->date_standardize($date) or return undef;
  return 0 if $self->{start_date} && $date lt $self->{start_date};
  return 0 if $self->{end_date}   && $date gt $self->{end_date};
  1;
}

### Label and label mapping/extraction management

sub default_target_mode { $Default_Target_Mode }
sub default_parse_mode  { $Default_Parse_Mode  }
sub default_granularity { $Default_Granularity }

sub set_label_pattern {
  my $self = shift;
  my %parms = @_;
  my $target_mode = $parms{target_mode} || $self->target_mode;
  my $parse_mode  = $parms{parse_mode}  || $self->parse_mode;
  my $label = $parms{label};
  croak "Column label required\n" unless $label;
  my $l2p = $self->{_label_pat}{$target_mode}{$parse_mode} ||= {};
  my $p2l = $self->{_pat_label}{$target_mode}{$parse_mode} ||= {};
  my $pattern = $parms{pattern};
  if ($pattern) {
    $l2p->{$label} = $pattern;
    delete $self->{label_map};
    delete $self->{pattern_map};
  }
  my $pat = $l2p->{$label} ||= ($label =~ $Default_Vol_Pat ?
                                  qr/\s*$label/i : qr/^\s*$label/i);
  $p2l->{$pat} ||= $label;
  $pat;
}

sub label_pattern {
  my $self = shift;
  my $target_mode = $self->target_mode;
  my $parse_mode  = $self->parse_mode;
  my $label = shift;
  croak "column label required\n" unless $label;
  my $l2p = $self->{_label_pat}{$target_mode}{$parse_mode} ||= {};
  my $pat = $l2p->{$label} || $self->set_label_pattern(label => $label);
  $pat;
}

sub label_column {
  my $self = shift;
  my @cols;
  if (!$self->{label_map}) {
    delete $self->{pattern_map};
    my @labels = $self->labels;
    foreach my $i (0 .. $#labels) {
      $self->{label_map}{$labels[$i]} = $i;
    }
  }
  foreach (@_) {
    croak "Unknown label '$_'\n" unless exists $self->{label_map}{$_};
    push(@cols, $self->{label_map}{$_});
  }
  unless (wantarray) {
    croak "multiple columns in scalar context\n" if @cols > 1;
    return $cols[0];
  }
  @cols;
}

sub pattern_column {
  my $self = shift;
  if (!$self->{pattern_map}) {
    my @patterns = $self->patterns;
    foreach my $i (0 .. $#patterns) {
      $self->{pattern_map}{$patterns[$i]} = $i;
    }
  }
  return unless @_;
  my $pattern = shift;
  croak "Unknown pattern '$pattern'\n" unless $self->{_pat_map}{$pattern};
  $self->{pattern_map{$pattern}};
}

sub pattern_map {
  my $self = shift;
  $self->pattern_column unless $self->{pattern_map};
  $self->{pattern_map};
}

sub label_map {
  my $self = shift;
  $self->label_column unless $self->{label_map};
  $self->{label_map};
}

sub pattern_label {
  my $self = shift;
  my %parms = @_;
  my $target_mode = $parms{target_mode} || $self->target_mode;
  my $parse_mode  = $parms{parse_mode}  || $self->parse_mode;
  my $pat = $parms{pattern} or croak "pattern required for label lookup\n";
  my $p2l = $self->{_pat_label}{$target_mode}{$parse_mode} ||= {};
  my $label = $p2l->{$pat};
  unless (defined $label) {
    delete $parms{pattern};
    $self->set_label_pattern(%parms, label => $_) foreach $self->labels;
  }
  $label;
}

sub patterns {
  my $self = shift;
  my %parms = @_;
  $parms{target_mode} ||= $self->target_mode;
  $parms{parse_mode}  ||= $self->parse_mode;
  map($self->label_pattern($_), $self->labels(%parms));
}

sub columns {
  my $self = shift;
  my %parms = @_;
  $parms{target_mode} ||= $self->target_mode;
  $parms{parse_mode}  ||= $self->parse_mode;
  $self->label_column($self->labels(%parms));
}

sub default_labels {
  my $self = shift;
  my %parms = @_;
  my $target_mode = $parms{target_mode} || $self->target_mode;
  my $tm = $Default_Labels{$target_mode};
  unless ($tm) {
    $tm = $Default_Labels{$self->default_target_mode};
  }
  my $parse_mode = $parms{parse_mode} || $self->parse_mode;
  my $labels = $tm->{$parse_mode};
  unless ($labels) {
    $labels = $tm->{$self->default_parse_mode};
  }
  @$labels;
}

sub labels {
  my $self  = shift;
  my %parms = @_;
  my $target_mode = $parms{target_mode} || $self->target_mode;
  my $parse_mode  = $parms{parse_mode}  || $self->parse_mode;
  my $tm = $self->{_labels}{$target_mode};
  if ($parms{labels} || ! $tm->{$parse_mode}) {
    delete $self->{label_map};
    delete $self->{pattern_map};
  }
  $tm->{$parse_mode} = $parms{labels} if $parms{labels};
  my $labels = $tm->{$parse_mode} ||= [$self->default_labels(
                                         target_mode => $target_mode,
                                         parse_mode  => $parse_mode)];
  @$labels;
}

sub parse_mode {
  my $self = shift;
  if (@_) {
    $self->{parse_mode} = shift;
  }
  $self->{parse_mode} || $self->default_parse_mode;
}

sub target_mode {
  my $self = shift;
  if (@_) {
    $self->{target_mode} = shift;
  }
  $self->{target_mode} || $self->default_target_mode;
}

sub granularity {
  my $self = shift;
  if (@_) {
    $self->{granularity} = shift;
  }
  $self->{granularity} || $self->default_granularity;
}

sub lineup {
  my $self = shift;
  $self->{lineup} = \@_ if @_;
  return unless $self->{lineup};
  @{$self->{lineup}};
}

### Parser methods

sub pre_parser {
  my($self, %parms) = @_;
  my $parse_mode = $parms{parse_mode} || $self->parse_mode;
  my $method = "${parse_mode}_pre_parser";
  return unless $self->can($method);
  $self->$method(%parms, parse_mode => $parse_mode);
}

sub parser {
  my($self, %parms) = @_;
  my $parse_mode = $parms{parse_mode} || $self->parse_mode;
  my $make_parser = "${parse_mode}_parser";
  $self->$make_parser(%parms, parse_mode => $parse_mode);
}

sub html_parser {
  # HTML::TableExtract supports automatic column reordering.
  my $self = shift;
  my $class = HTML_CLASS;
  my @labels = $self->labels(@_);
  my @patterns = $self->patterns(@_);
  my(%pat_map, %label_map);
  $pat_map{$patterns[$_]} = $_ foreach 0 .. $#patterns;
  $label_map{$labels[$_]} = $_ foreach 0 .. $#labels;
  $self->pattern_map(\%pat_map);
  $self->label_map(\%label_map);
  sub {
    my $data = shift;
    my $html_string;
    if (ref $data) {
      local($/);
      $html_string = <$data>;
    }
    else {
      $html_string = $data;
    }
    my %te_parms = (
      headers => \@patterns,
      automap => 1,
    );
    $te_parms{debug} = $self->{debug} if $self->{debug} > 2;
    my $te = $class->new(%te_parms) or croak "Problem creating $class\n";
    $te->parse($html_string);
    $te->eof;
    my $ts = $te->first_table_found;
    [ $ts ? $ts->rows() : ()];
  }
}

sub csv_parser {
  # Text::CSV_XS doesn't column slice or re-order, so we do.
  my $self = shift;
  my @patterns = $self->patterns(@_);
  sub {
    my $data = shift;
    return [] unless defined $data;
    my @csv_lines = ref $data ? <$data> : split("\n", $data);
    # BOM squad (byte order mark, as csv from google tends to be)
    if ($csv_lines[0] =~ s/^\xEF\xBB\xBF//) {
      for my $i (0 .. $#csv_lines) {
        utf8::decode($csv_lines[$i]);
      }
    }
    # might be unix, windows, or mac style newlines
    s/\s+$// foreach @csv_lines;
    return [] if !@csv_lines || $csv_lines[0] =~ /(no data)|error/i;
    # attempt to get rid of comments at front of csv data
    while (@csv_lines) {
      last if $csv_lines[0] =~ /date/i || $csv_lines[0] =~ /\d+$/;
      print STDERR "CSV reject line: $csv_lines[0]\n" if $self->{verbose};
      shift @csv_lines;
    }
    my $first_line = $csv_lines[0];
    my $sep_char = $first_line =~ /date\s*(\S)/i ? $1 : ',';
    my $cp = $CSV_Class->new({sep_char => $sep_char, binary => 1})
      or croak "Problem creating $CSV_Class\n";
    my @pat_slice;
    if ($first_line =~ /date/i) {
      # derive column detection and ordering
      $cp->parse($first_line) or croak ("Problem parsing (" .
        $cp->error_input . ") : " . $cp->error_diag . "\n");
      my @headers = $cp->fields;
      my @pats = @patterns;
      my @labels = map($self->pattern_label(pattern => $_), @patterns);
      my(%pat_map, %label_map);
      HEADER: for my $i (0 .. $#headers) {
        last unless @pats;
        my $header = $headers[$i];
        for my $pi (0 .. $#pats) {
          my $pat = $pats[$pi];
          if ($header =~ /$pat/) {
            my $label = $labels[$pi];
            splice(@pats,   $pi, 1);
            splice(@labels, $pi, 1);
            $pat_map{$pat} = $i;
            $label_map{$label} = $i;
            next HEADER;
          }
        }
      }
      shift @csv_lines;
      @pat_slice = map($pat_map{$_}, @patterns);
    }
    else {
      # no header row, trust natural order and presence
      @pat_slice = 0 .. $#patterns;
    }
    my @rows;
    foreach my $line (@csv_lines) {
      $cp->parse($line) or next;
      my @fields = $cp->fields;
      push(@rows, [@fields[@pat_slice]]);
    }
    \@rows;
  };
}

### Accessors, generators

sub start_date {
  my $self = shift;
  if (@_) {
    my $start_date = shift;
    my $clear = @_ ? shift : 1;
    $self->clear_cache if $clear;
    $self->{start_date} = defined $start_date ?
      $self->date_standardize($start_date) : undef;
  }
  $self->{start_date};
}

sub end_date {
  my $self = shift;
  if (@_) {
    my $end_date = shift;
    my $clear = @_ ? shift : 1;
    $self->clear_cache if $clear;
    $self->{end_date} = defined $end_date ?
      $self->date_standardize($end_date) : undef;
  }
  $self->{end_date};
}

sub date_standardize {
  my($self, @dates) = @_;
  return unless @dates;
  foreach (@dates) {
    $_ = ParseDate($_) or Carp::confess "Could not parse date '$_'\n";
    s/\d\d:.*//;
  }
  @dates > 1 ? @dates : ($dates[0]);
}

sub mydates {
  my $self = shift;
  $self->dates($self->{start_date}, $self->{end_date});
}

sub dates {
  my($self, $sdate, $edate) = @_;
  $sdate && $edate or croak "Start date and end date strings required\n";
  my($sd, $ed) = sort($self->date_standardize($sdate, $edate));
  my @dates;
  push(@dates, $sd) if Date_IsWorkDay($sd);
  my $cd = $self->date_standardize(Date_NextWorkDay($sd, 1));
  while ($cd <= $ed) {
    push(@dates, $cd);
    $cd = $self->date_standardize(Date_NextWorkDay($cd));
  }
  @dates;
}

sub symbols {
  my($self, @symbols) = @_;
  if (@symbols) {
    my %seen;
    grep(++$seen{$_}, grep(uc $_, @symbols));
    $self->{symbols} = [sort keys %seen];
    $self->clear_cache;
  }
  @{$self->{symbols}};
}

sub successors {
  my $self = shift;
  @{$self->{successors}};
}

sub clear_cache {
  my $self = shift;
  delete $self->{url_cache};
  delete $self->{results};
  1;
}

sub result_modes {
  my $self = shift;
  return () unless $self->{results};
  sort keys %{$self->{results}};
}

sub result_symbols {
  my($self, $target_mode) = @_;
  $target_mode ||= $self->target_mode;
  return () unless $self->{sources}{$target_mode};
  sort keys %{$self->{results}{$target_mode}};
}

sub results {
  my($self, $target_mode, $symbol) = @_;
  $self->{results}{$target_mode}{$symbol};
}

sub quote_source    { shift->source(shift, 'quote')    }
sub dividend_source { shift->source(shift, 'dividend') }
sub split_source    { shift->source(shift, 'split')    }
sub intraday_source { shift->source(shift, 'intraday') }

sub row_filter { shift->{row_filter} }

sub source {
  my($self, $symbol, $target_mode) = @_;
  croak "Ticker symbol required\n" unless $symbol;
  $target_mode ||= $self->target_mode;
  $self->{sources}{$target_mode}{$symbol} || '';
}

sub _target_source {
  my($self, $target_mode, $symbol, $source) = @_;
  croak "Target mode required\n"   unless $target_mode;
  croak "Ticker symbol required\n" unless $symbol;
  $symbol = uc $symbol;
  if ($source) {
    $self->{sources}{$target_mode}{$symbol} = $source;
  }
  $self->{sources}{$target_mode}{$symbol};
}

###

sub _summon_champion {
  # Instantiate the next class in line if this class failed in
  # fetching any quotes. Make sure and pass along the remaining
  # champions to the new champion.
  my($self, $champion_class, @bad_symbols) = @_;
  return undef unless ref $self->{lineup} && @{$self->{lineup}};
  print STDERR "Loading $champion_class\n" if $self->{verbose};
  eval "require $champion_class;";
  die $@ if $@;
  my $champion = $champion_class->new
    (
     symbols    => [@bad_symbols],
     start_date => $self->{start_date},
     end_date   => $self->{end_date},
     adjusted   => $self->{adjusted},
     verbose    => $self->{verbose},
     lineup     => [],
    );
  $champion;
}

### Toolbox

sub save_query    { shift->_save_restore_query(1) }
sub restore_query { shift->_save_restore_query(0) }
sub _save_restore_query {
  my($self, $save) = @_;
  $save = 1 unless defined $save;
  foreach (qw(parse_mode target_mode start_date end_date granularity quiet)) {
    my $qstr = "_query_$_";
    if ($save) {
      $self->{$qstr} = $self->{$_};
    }
    else {
      $self->{$_} = $self->{$qstr} if exists $self->{$qstr};
    }
  }
  $self;
}

sub ymd {
  my $self = shift;
  my @res = $_[0] =~ /^\s*(\d{4})(\d{2})(\d{2})/o;
  shift =~ /^\s*(\d{4})(\d{2})(\d{2})/o;
}

sub date_iterator {
  my $self = shift;
  my %parms = @_;
  my $start_date = $parms{start_date};
  my $end_date   = $parms{end_date} || 'today';
  my $increment  = $parms{increment};
  my $units      = $parms{units} || 'days';
  $increment && $increment > 0 or croak "Increment > 0 required\n";
  $start_date = ParseDate($start_date) if $start_date;
  $end_date   = ParseDate($end_date)   if $end_date;
  if ($start_date && $start_date gt $end_date) {
    ($start_date, $end_date) = ($end_date, $start_date);
  }
  my($low_date, $high_date);
  $high_date = $end_date;
  sub {
    return () unless $end_date;
    $low_date = DateCalc($high_date, "- $increment $units");
    if ($start_date && $low_date lt $start_date) {
      $low_date = $start_date;
      undef $start_date;
      undef $end_date;
      return () if $low_date eq $high_date;
    }
    my @date_pair = ($low_date, $high_date);
    $high_date = $low_date;
    @date_pair;
  }
}

1;

__END__

=head1 NAME

Finance::QuoteHist::Generic - Base class for retrieving historical stock quotes.

=head1 SYNOPSIS

  package Finance::QuoteHist::MyFavoriteSite;
  use strict;
  use vars qw(@ISA);
  use Finance::QuoteHist::Generic;
  @ISA = qw(Finance::QuoteHist::Generic);

  sub url_maker {
    # This method returns a code reference for a routine that, upon
    # repeated invocation, will provide however many URLs are necessary
    # to fully obtain the historical data for a given target mode and
    # parsing mode.
  }

=head1 DESCRIPTION

This is the base class for retrieving historical stock quotes. It is
built around LWP::UserAgent. Page results are currently parsed as either
CSV or HTML tables.

In order to actually retrieve historical stock quotes, this class should
be subclassed and tailored to a particular web site. In particular, the
C<url_maker()> factory method should be overridden, which provides a
code reference to a routine that provides however many URLs are
necessary to retrieve the data over a list of symbols within the given
date range, for a particular target (quotes, dividends, splits).
Different sites have different formats and different limitations on how
many quotes are returned for each query. See Finance::QuoteHist::Yahoo
for an example of how to do this.

For more complicated sites, such as Yahoo, overriding additional methods
might be necessary for dealing with things such as splits and dividends.

=head1 METHODS

=over

=item new()

Returns a new Finance::QuoteHist::Generic object.  Valid attributes
are:

=over

=item start_date

=item end_date

Specify the date range from which you would like historical quotes.
These dates get parsed by the C<ParseDate()> method in Date::Manip, so
see L<Date::Manip(3)> for more information on valid date strings. They
are quite flexible, and include such strings as '1 year ago'. Date
boundaries can also be dynamically set with methods of the same
name. The absence of a start date means go to the beginning of the
history. The absence of an end date means go up to the most recent
historical date. The absence of both means grab everything.

=item symbols

Indicates which ticker symbols to include in the search for historical
quotes. Passed either as a string (for single ticker) or an array ref
for multiple tickers.

=item granularity

Returns rows at 'daily', 'weekly', or 'monthly' levels of granularity.
Defaults to 'daily'.

=item attempts

Sets how persistently the module tries to retrieve the quotes. There are
two places this will manifest. First, if there are what appear to be
network errors, this many network connections are attempted for that
URL. Secondly, for quotes only, if pages were successfully retrieved,
but they contained no quotes, this number of attempts are made to
retrieve a document with data. Sometimes sites will report a temporary
internal error via HTML, and if it is truly transitory this will usually
get around it. The default is 3.

=item lineup

Passed as an array reference (or scalar for single class), this list
indicates which Finance::QuoteHist::Generic sub classes should be
invoked in the event this class fails in its attempt to retrieve
historical quotes. In the event of failure, the first class in this list
is invoked with the same parameters as the original class, and the
remaining classes are passed as the lineup to the new class. This sets
up a daisy chain of redundancy in the event a particular site is hosed.
See L<Finance::QuoteHist(3)> to see an example of how this is done in a
top level invocation of these modules. This list is empty by default.

=item quote_precision

Sets the number of decimal places to which quote values are rounded.
This might be of particular significance if there is auto-adjustment
taking place (which is only under particular circumstances
currently...see L<Finance::QuoteHist::Yahoo>). Setting this to 0 will
disable the rounding behavior, returning the quote values as they
appear on the sites (assuming no auto-adjustment has taken place). The
default is 4.

=item row_filter

When provided a subroutine reference, the routine is invoked with an
array reference for each raw row retrieved from the quote source. This
allows user-defined filtering or formatting for the items of each
row. This routine is invoked before any built-in routines are called
on the row. The array must be modified directly rather than returned
as a value. Use sparingly since the built-in filtering and
normalizing routines do expect each row to more or less look like
historical stock data. Rearranging the order of the columns in each row
is contraindicated.

=item env_proxy

When set, instructs the underlying LWP::UserAgent to load proxy
configuration information from environment variables. See the C<ua()>
method and L<LWP::UserAgent> for more information.

=item auto_proxy

Same as env_proxy, but tests first to see if $ENV{http_proxy} is
present.

=item verbose

When set, many status messages are printed to STDERR indicating
progression through URLs and lineup invocations.

=item quiet

When set, certain failure messages are suppressed from appearing on
STDERR. These messages would normally appear regardless the setting of
the C<verbose> flag.

=back

=back

The following methods are the primary user interface methods; methods
of interest to developers wishing to make their own site-specific
instance of this module will find information on overriding methods
further below.

=over

=item quotes()

Retrieves historical quotes for all provided symbols over the specified
date range. Depending on context, returns either a list of rows or an
array reference to the same list of rows.

=item dividends()

=item splits()

If available, retrieves dividend or split information for all provided
symbols over the specified date range. If there are no site-specific
subclassed modules in the B<lineup> capable of getting dividends or
splits, the user will be notified on STDERR unless the B<quiet> flag was
requested during object creation.

=item start_date(date_string)

=item end_date(date_string)

Set the date boundaries of all queries. The B<date_string> is
interpreted by the Date::Manip module. The absence of a start date means
retrieve back to the beginning of that ticker's history. The absence of
an end date means retrieve up to the latest date in the history.

=item clear_cache()

When results are gathered for a particular date range, whether they be
via direct query or incidental extraction, they are cached. This cache
is cleared by invoking this method directly, by resetting the boundary
dates of the query, or by changing the C<adjusted()> setting.

=item quote_source(ticker_symbol)

=item dividend_source(ticker_symbol)

=item split_source(ticker_symbol)

After query, these methods can be used to find out which particular
subclass in the B<lineup> fulfilled the corresponding request for a
particular ticker symbol.

=back

The following methods are the primary methods of interest for developers
wishing to make a site-specific subclass. The url_maker() factory is
typically all that is necessary.

=over

=item url_maker()

Returns a subroutine reference that serves as an iterrator for producing
URLs based on target and parse mode. Repeated calls to this routine
produce subsequent URLs in the sequence.

=item extractors()

For a particular target mode and parse mode, returns a hash containing
code references to extraction routines for the remaining targets. For
example, for target 'quote' in parse mode 'html' there might be
extractor routines for both 'dividend' and 'split'.

=item ua()

Accessor method for the LWP::UserAgent object used to process
HTTP::Request for individual URLs. This can be handy for such things as
configuring proxy access for the underlying user agent. Example:

 # Manual configuration
 $qh1->ua->proxy(['http'], 'http://proxy.sn.no:8001/');

 # Load from environment variables
 $qh2->ua->env_proxy();

See L<LWP::UserAgent> for more information on the capabilities
of that module.

=back

The following are potentially useful for calling within methods
overridden above:

=over

=item parse_mode($parse_mode)

Set the current parsing mode. Currently parsers are available for html
and csv.

=item target_mode($target_mode)

Return the current target mode.

=item dates($start_date, $end_date)

Returns a list of business days between and including the provided
boundary dates. If no arguments are provided, B<start_date> and
B<end_date> default to the currently specified date range.

=item labels(%parms)

Used to override the default labels for a given target mode and parse
mode. Takes the following named parameters:

=over

=item target_mode

Can currently be 'quote', 'dividend', or 'split'. Default is 'quote'.

=item parse mode

Can currently be 'csv' or 'html'. The default is typically 'csv' but
might vary depending on the quote source.

=item labels

The following are the default labels. Text entries convert to case-
insensitive regular expressions):

  target_mode
  -------------------------------------------------------
  quote    => ['date','open','high','low','close',qr(vol|shares)i]
  dividend => ['date','div']
  split    => ['date','post','pre']

=back

=back

=head1 DISCLAIMER

The data returned from these modules is in no way guaranteed, nor are
the developers responsible in any way for how this data (or lack
thereof) is used. The interface is based on URLs and page layouts that
might change at any time. Even though these modules are designed to be
adaptive under these circumstances, they will at some point probably be
unable to retrieve data unless fixed or provided with new parameters.
Furthermore, the data from these web sites is usually not even
guaranteed by the web sites themselves, and oftentimes is acquired
elsewhere. See the documentation for each site-specific module for more
information regarding the disclaimer for that site.

Above all, play nice.

=head1 AUTHOR

Matthew P. Sisk, E<lt>F<sisk@mojotoad.com>E<gt>

=head1 COPYRIGHT

Copyright (c) 2000-2013 Matthew P. Sisk. All rights reserved. All wrongs
revenged. This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

=head1 SEE ALSO

Finance::QuoteHist(3), HTML::TableExtract(3), Date::Manip(3),
perlmodlib(1), perl(1).

=cut