summaryrefslogtreecommitdiff
path: root/Master/tlpkg/tlperl/lib/Pod/Text.pm
blob: f57256f2d9361db457e2a02bdd58b5808f2fdf1c (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
# Pod::Text -- Convert POD data to formatted ASCII text.
#
# This module converts POD to formatted text.  It replaces the old Pod::Text
# module that came with versions of Perl prior to 5.6.0 and attempts to match
# its output except for some specific circumstances where other decisions
# seemed to produce better output.  It uses Pod::Parser and is designed to be
# very easy to subclass.
#
# Perl core hackers, please note that this module is also separately
# maintained outside of the Perl core as part of the podlators.  Please send
# me any patches at the address above in addition to sending them to the
# standard Perl mailing lists.
#
# Copyright 1999, 2000, 2001, 2002, 2004, 2006, 2008, 2009, 2012, 2013
#     Russ Allbery <rra@stanford.edu>
#
# This program is free software; you may redistribute it and/or modify it
# under the same terms as Perl itself.

##############################################################################
# Modules and declarations
##############################################################################

package Pod::Text;

require 5.004;

use strict;
use vars qw(@ISA @EXPORT %ESCAPES $VERSION);

use Carp qw(carp croak);
use Encode qw(encode);
use Exporter ();
use Pod::Simple ();

@ISA = qw(Pod::Simple Exporter);

# We have to export pod2text for backward compatibility.
@EXPORT = qw(pod2text);

$VERSION = '3.17';

##############################################################################
# Initialization
##############################################################################

# This function handles code blocks.  It's registered as a callback to
# Pod::Simple and therefore doesn't work as a regular method call, but all it
# does is call output_code with the line.
sub handle_code {
    my ($line, $number, $parser) = @_;
    $parser->output_code ($line . "\n");
}

# Initialize the object and set various Pod::Simple options that we need.
# Here, we also process any additional options passed to the constructor or
# set up defaults if none were given.  Note that all internal object keys are
# in all-caps, reserving all lower-case object keys for Pod::Simple and user
# arguments.
sub new {
    my $class = shift;
    my $self = $class->SUPER::new;

    # Tell Pod::Simple to handle S<> by automatically inserting &nbsp;.
    $self->nbsp_for_S (1);

    # Tell Pod::Simple to keep whitespace whenever possible.
    if ($self->can ('preserve_whitespace')) {
        $self->preserve_whitespace (1);
    } else {
        $self->fullstop_space_harden (1);
    }

    # The =for and =begin targets that we accept.
    $self->accept_targets (qw/text TEXT/);

    # Ensure that contiguous blocks of code are merged together.  Otherwise,
    # some of the guesswork heuristics don't work right.
    $self->merge_text (1);

    # Pod::Simple doesn't do anything useful with our arguments, but we want
    # to put them in our object as hash keys and values.  This could cause
    # problems if we ever clash with Pod::Simple's own internal class
    # variables.
    my %opts = @_;
    my @opts = map { ("opt_$_", $opts{$_}) } keys %opts;
    %$self = (%$self, @opts);

    # Send errors to stderr if requested.
    if ($$self{opt_stderr} and not $$self{opt_errors}) {
        $$self{opt_errors} = 'stderr';
    }
    delete $$self{opt_stderr};

    # Validate the errors parameter and act on it.
    if (not defined $$self{opt_errors}) {
        $$self{opt_errors} = 'pod';
    }
    if ($$self{opt_errors} eq 'stderr' || $$self{opt_errors} eq 'die') {
        $self->no_errata_section (1);
        $self->complain_stderr (1);
        if ($$self{opt_errors} eq 'die') {
            $$self{complain_die} = 1;
        }
    } elsif ($$self{opt_errors} eq 'pod') {
        $self->no_errata_section (0);
        $self->complain_stderr (0);
    } elsif ($$self{opt_errors} eq 'none') {
        $self->no_whining (1);
    } else {
        croak (qq(Invalid errors setting: "$$self{errors}"));
    }
    delete $$self{errors};

    # Initialize various things from our parameters.
    $$self{opt_alt}      = 0  unless defined $$self{opt_alt};
    $$self{opt_indent}   = 4  unless defined $$self{opt_indent};
    $$self{opt_margin}   = 0  unless defined $$self{opt_margin};
    $$self{opt_loose}    = 0  unless defined $$self{opt_loose};
    $$self{opt_sentence} = 0  unless defined $$self{opt_sentence};
    $$self{opt_width}    = 76 unless defined $$self{opt_width};

    # Figure out what quotes we'll be using for C<> text.
    $$self{opt_quotes} ||= '"';
    if ($$self{opt_quotes} eq 'none') {
        $$self{LQUOTE} = $$self{RQUOTE} = '';
    } elsif (length ($$self{opt_quotes}) == 1) {
        $$self{LQUOTE} = $$self{RQUOTE} = $$self{opt_quotes};
    } elsif ($$self{opt_quotes} =~ /^(.)(.)$/
             || $$self{opt_quotes} =~ /^(..)(..)$/) {
        $$self{LQUOTE} = $1;
        $$self{RQUOTE} = $2;
    } else {
        croak qq(Invalid quote specification "$$self{opt_quotes}");
    }

    # If requested, do something with the non-POD text.
    $self->code_handler (\&handle_code) if $$self{opt_code};

    # Return the created object.
    return $self;
}

##############################################################################
# Core parsing
##############################################################################

# This is the glue that connects the code below with Pod::Simple itself.  The
# goal is to convert the event stream coming from the POD parser into method
# calls to handlers once the complete content of a tag has been seen.  Each
# paragraph or POD command will have textual content associated with it, and
# as soon as all of a paragraph or POD command has been seen, that content
# will be passed in to the corresponding method for handling that type of
# object.  The exceptions are handlers for lists, which have opening tag
# handlers and closing tag handlers that will be called right away.
#
# The internal hash key PENDING is used to store the contents of a tag until
# all of it has been seen.  It holds a stack of open tags, each one
# represented by a tuple of the attributes hash for the tag and the contents
# of the tag.

# Add a block of text to the contents of the current node, formatting it
# according to the current formatting instructions as we do.
sub _handle_text {
    my ($self, $text) = @_;
    my $tag = $$self{PENDING}[-1];
    $$tag[1] .= $text;
}

# Given an element name, get the corresponding method name.
sub method_for_element {
    my ($self, $element) = @_;
    $element =~ tr/-/_/;
    $element =~ tr/A-Z/a-z/;
    $element =~ tr/_a-z0-9//cd;
    return $element;
}

# Handle the start of a new element.  If cmd_element is defined, assume that
# we need to collect the entire tree for this element before passing it to the
# element method, and create a new tree into which we'll collect blocks of
# text and nested elements.  Otherwise, if start_element is defined, call it.
sub _handle_element_start {
    my ($self, $element, $attrs) = @_;
    my $method = $self->method_for_element ($element);

    # If we have a command handler, we need to accumulate the contents of the
    # tag before calling it.
    if ($self->can ("cmd_$method")) {
        push (@{ $$self{PENDING} }, [ $attrs, '' ]);
    } elsif ($self->can ("start_$method")) {
        my $method = 'start_' . $method;
        $self->$method ($attrs, '');
    }
}

# Handle the end of an element.  If we had a cmd_ method for this element,
# this is where we pass along the text that we've accumulated.  Otherwise, if
# we have an end_ method for the element, call that.
sub _handle_element_end {
    my ($self, $element) = @_;
    my $method = $self->method_for_element ($element);

    # If we have a command handler, pull off the pending text and pass it to
    # the handler along with the saved attribute hash.
    if ($self->can ("cmd_$method")) {
        my $tag = pop @{ $$self{PENDING} };
        my $method = 'cmd_' . $method;
        my $text = $self->$method (@$tag);
        if (defined $text) {
            if (@{ $$self{PENDING} } > 1) {
                $$self{PENDING}[-1][1] .= $text;
            } else {
                $self->output ($text);
            }
        }
    } elsif ($self->can ("end_$method")) {
        my $method = 'end_' . $method;
        $self->$method ();
    }
}

##############################################################################
# Output formatting
##############################################################################

# Wrap a line, indenting by the current left margin.  We can't use Text::Wrap
# because it plays games with tabs.  We can't use formline, even though we'd
# really like to, because it screws up non-printing characters.  So we have to
# do the wrapping ourselves.
sub wrap {
    my $self = shift;
    local $_ = shift;
    my $output = '';
    my $spaces = ' ' x $$self{MARGIN};
    my $width = $$self{opt_width} - $$self{MARGIN};
    while (length > $width) {
        if (s/^([^\n]{0,$width})\s+// || s/^([^\n]{$width})//) {
            $output .= $spaces . $1 . "\n";
        } else {
            last;
        }
    }
    $output .= $spaces . $_;
    $output =~ s/\s+$/\n\n/;
    return $output;
}

# Reformat a paragraph of text for the current margin.  Takes the text to
# reformat and returns the formatted text.
sub reformat {
    my $self = shift;
    local $_ = shift;

    # If we're trying to preserve two spaces after sentences, do some munging
    # to support that.  Otherwise, smash all repeated whitespace.
    if ($$self{opt_sentence}) {
        s/ +$//mg;
        s/\.\n/. \n/g;
        s/\n/ /g;
        s/   +/  /g;
    } else {
        s/\s+/ /g;
    }
    return $self->wrap ($_);
}

# Output text to the output device.  Replace non-breaking spaces with spaces
# and soft hyphens with nothing, and then try to fix the output encoding if
# necessary to match the input encoding unless UTF-8 output is forced.  This
# preserves the traditional pass-through behavior of Pod::Text.
sub output {
    my ($self, @text) = @_;
    my $text = join ('', @text);
    $text =~ tr/\240\255/ /d;
    unless ($$self{opt_utf8} || $$self{CHECKED_ENCODING}) {
        my $encoding = $$self{encoding} || '';
        if ($encoding) {
            eval { binmode ($$self{output_fh}, ":encoding($encoding)") };
        }
        $$self{CHECKED_ENCODING} = 1;
    }
    if ($$self{ENCODE}) {
        print { $$self{output_fh} } encode ('UTF-8', $text);
    } else {
        print { $$self{output_fh} } $text;
    }
}

# Output a block of code (something that isn't part of the POD text).  Called
# by preprocess_paragraph only if we were given the code option.  Exists here
# only so that it can be overridden by subclasses.
sub output_code { $_[0]->output ($_[1]) }

##############################################################################
# Document initialization
##############################################################################

# Set up various things that have to be initialized on a per-document basis.
sub start_document {
    my ($self, $attrs) = @_;
    if ($$attrs{contentless} && !$$self{ALWAYS_EMIT_SOMETHING}) {
        $$self{CONTENTLESS} = 1;
        return;
    } else {
        delete $$self{CONTENTLESS};
    }
    my $margin = $$self{opt_indent} + $$self{opt_margin};

    # Initialize a few per-document variables.
    $$self{INDENTS} = [];       # Stack of indentations.
    $$self{MARGIN}  = $margin;  # Default left margin.
    $$self{PENDING} = [[]];     # Pending output.

    # We have to redo encoding handling for each document.
    delete $$self{CHECKED_ENCODING};

    # When UTF-8 output is set, check whether our output file handle already
    # has a PerlIO encoding layer set.  If it does not, we'll need to encode
    # our output before printing it (handled in the output() sub).  Wrap the
    # check in an eval to handle versions of Perl without PerlIO.
    $$self{ENCODE} = 0;
    if ($$self{opt_utf8}) {
        $$self{ENCODE} = 1;
        eval {
            my @options = (output => 1, details => 1);
            my $flag = (PerlIO::get_layers ($$self{output_fh}, @options))[-1];
            if ($flag & PerlIO::F_UTF8 ()) {
                $$self{ENCODE} = 0;
            }
        };
    }

    return '';
}

# Handle the end of the document.  The only thing we do is handle dying on POD
# errors, since Pod::Parser currently doesn't.
sub end_document {
    my ($self) = @_;
    if ($$self{complain_die} && $self->errors_seen) {
        croak ("POD document had syntax errors");
    }
}

##############################################################################
# Text blocks
##############################################################################

# Intended for subclasses to override, this method returns text with any
# non-printing formatting codes stripped out so that length() correctly
# returns the length of the text.  For basic Pod::Text, it does nothing.
sub strip_format {
    my ($self, $string) = @_;
    return $string;
}

# This method is called whenever an =item command is complete (in other words,
# we've seen its associated paragraph or know for certain that it doesn't have
# one).  It gets the paragraph associated with the item as an argument.  If
# that argument is empty, just output the item tag; if it contains a newline,
# output the item tag followed by the newline.  Otherwise, see if there's
# enough room for us to output the item tag in the margin of the text or if we
# have to put it on a separate line.
sub item {
    my ($self, $text) = @_;
    my $tag = $$self{ITEM};
    unless (defined $tag) {
        carp "Item called without tag";
        return;
    }
    undef $$self{ITEM};

    # Calculate the indentation and margin.  $fits is set to true if the tag
    # will fit into the margin of the paragraph given our indentation level.
    my $indent = $$self{INDENTS}[-1];
    $indent = $$self{opt_indent} unless defined $indent;
    my $margin = ' ' x $$self{opt_margin};
    my $tag_length = length ($self->strip_format ($tag));
    my $fits = ($$self{MARGIN} - $indent >= $tag_length + 1);

    # If the tag doesn't fit, or if we have no associated text, print out the
    # tag separately.  Otherwise, put the tag in the margin of the paragraph.
    if (!$text || $text =~ /^\s+$/ || !$fits) {
        my $realindent = $$self{MARGIN};
        $$self{MARGIN} = $indent;
        my $output = $self->reformat ($tag);
        $output =~ s/^$margin /$margin:/ if ($$self{opt_alt} && $indent > 0);
        $output =~ s/\n*$/\n/;

        # If the text is just whitespace, we have an empty item paragraph;
        # this can result from =over/=item/=back without any intermixed
        # paragraphs.  Insert some whitespace to keep the =item from merging
        # into the next paragraph.
        $output .= "\n" if $text && $text =~ /^\s*$/;

        $self->output ($output);
        $$self{MARGIN} = $realindent;
        $self->output ($self->reformat ($text)) if ($text && $text =~ /\S/);
    } else {
        my $space = ' ' x $indent;
        $space =~ s/^$margin /$margin:/ if $$self{opt_alt};
        $text = $self->reformat ($text);
        $text =~ s/^$margin /$margin:/ if ($$self{opt_alt} && $indent > 0);
        my $tagspace = ' ' x $tag_length;
        $text =~ s/^($space)$tagspace/$1$tag/ or warn "Bizarre space in item";
        $self->output ($text);
    }
}

# Handle a basic block of text.  The only tricky thing here is that if there
# is a pending item tag, we need to format this as an item paragraph.
sub cmd_para {
    my ($self, $attrs, $text) = @_;
    $text =~ s/\s+$/\n/;
    if (defined $$self{ITEM}) {
        $self->item ($text . "\n");
    } else {
        $self->output ($self->reformat ($text . "\n"));
    }
    return '';
}

# Handle a verbatim paragraph.  Just print it out, but indent it according to
# our margin.
sub cmd_verbatim {
    my ($self, $attrs, $text) = @_;
    $self->item if defined $$self{ITEM};
    return if $text =~ /^\s*$/;
    $text =~ s/^(\n*)([ \t]*\S+)/$1 . (' ' x $$self{MARGIN}) . $2/gme;
    $text =~ s/\s*$/\n\n/;
    $self->output ($text);
    return '';
}

# Handle literal text (produced by =for and similar constructs).  Just output
# it with the minimum of changes.
sub cmd_data {
    my ($self, $attrs, $text) = @_;
    $text =~ s/^\n+//;
    $text =~ s/\n{0,2}$/\n/;
    $self->output ($text);
    return '';
}

##############################################################################
# Headings
##############################################################################

# The common code for handling all headers.  Takes the header text, the
# indentation, and the surrounding marker for the alt formatting method.
sub heading {
    my ($self, $text, $indent, $marker) = @_;
    $self->item ("\n\n") if defined $$self{ITEM};
    $text =~ s/\s+$//;
    if ($$self{opt_alt}) {
        my $closemark = reverse (split (//, $marker));
        my $margin = ' ' x $$self{opt_margin};
        $self->output ("\n" . "$margin$marker $text $closemark" . "\n\n");
    } else {
        $text .= "\n" if $$self{opt_loose};
        my $margin = ' ' x ($$self{opt_margin} + $indent);
        $self->output ($margin . $text . "\n");
    }
    return '';
}

# First level heading.
sub cmd_head1 {
    my ($self, $attrs, $text) = @_;
    $self->heading ($text, 0, '====');
}

# Second level heading.
sub cmd_head2 {
    my ($self, $attrs, $text) = @_;
    $self->heading ($text, $$self{opt_indent} / 2, '==  ');
}

# Third level heading.
sub cmd_head3 {
    my ($self, $attrs, $text) = @_;
    $self->heading ($text, $$self{opt_indent} * 2 / 3 + 0.5, '=   ');
}

# Fourth level heading.
sub cmd_head4 {
    my ($self, $attrs, $text) = @_;
    $self->heading ($text, $$self{opt_indent} * 3 / 4 + 0.5, '-   ');
}

##############################################################################
# List handling
##############################################################################

# Handle the beginning of an =over block.  Takes the type of the block as the
# first argument, and then the attr hash.  This is called by the handlers for
# the four different types of lists (bullet, number, text, and block).
sub over_common_start {
    my ($self, $attrs) = @_;
    $self->item ("\n\n") if defined $$self{ITEM};

    # Find the indentation level.
    my $indent = $$attrs{indent};
    unless (defined ($indent) && $indent =~ /^\s*[-+]?\d{1,4}\s*$/) {
        $indent = $$self{opt_indent};
    }

    # Add this to our stack of indents and increase our current margin.
    push (@{ $$self{INDENTS} }, $$self{MARGIN});
    $$self{MARGIN} += ($indent + 0);
    return '';
}

# End an =over block.  Takes no options other than the class pointer.  Output
# any pending items and then pop one level of indentation.
sub over_common_end {
    my ($self) = @_;
    $self->item ("\n\n") if defined $$self{ITEM};
    $$self{MARGIN} = pop @{ $$self{INDENTS} };
    return '';
}

# Dispatch the start and end calls as appropriate.
sub start_over_bullet { $_[0]->over_common_start ($_[1]) }
sub start_over_number { $_[0]->over_common_start ($_[1]) }
sub start_over_text   { $_[0]->over_common_start ($_[1]) }
sub start_over_block  { $_[0]->over_common_start ($_[1]) }
sub end_over_bullet { $_[0]->over_common_end }
sub end_over_number { $_[0]->over_common_end }
sub end_over_text   { $_[0]->over_common_end }
sub end_over_block  { $_[0]->over_common_end }

# The common handler for all item commands.  Takes the type of the item, the
# attributes, and then the text of the item.
sub item_common {
    my ($self, $type, $attrs, $text) = @_;
    $self->item if defined $$self{ITEM};

    # Clean up the text.  We want to end up with two variables, one ($text)
    # which contains any body text after taking out the item portion, and
    # another ($item) which contains the actual item text.  Note the use of
    # the internal Pod::Simple attribute here; that's a potential land mine.
    $text =~ s/\s+$//;
    my ($item, $index);
    if ($type eq 'bullet') {
        $item = '*';
    } elsif ($type eq 'number') {
        $item = $$attrs{'~orig_content'};
    } else {
        $item = $text;
        $item =~ s/\s*\n\s*/ /g;
        $text = '';
    }
    $$self{ITEM} = $item;

    # If body text for this item was included, go ahead and output that now.
    if ($text) {
        $text =~ s/\s*$/\n/;
        $self->item ($text);
    }
    return '';
}

# Dispatch the item commands to the appropriate place.
sub cmd_item_bullet { my $self = shift; $self->item_common ('bullet', @_) }
sub cmd_item_number { my $self = shift; $self->item_common ('number', @_) }
sub cmd_item_text   { my $self = shift; $self->item_common ('text',   @_) }
sub cmd_item_block  { my $self = shift; $self->item_common ('block',  @_) }

##############################################################################
# Formatting codes
##############################################################################

# The simple ones.
sub cmd_b { return $_[0]{alt} ? "``$_[2]''" : $_[2] }
sub cmd_f { return $_[0]{alt} ? "\"$_[2]\"" : $_[2] }
sub cmd_i { return '*' . $_[2] . '*' }
sub cmd_x { return '' }

# Apply a whole bunch of messy heuristics to not quote things that don't
# benefit from being quoted.  These originally come from Barrie Slaymaker and
# largely duplicate code in Pod::Man.
sub cmd_c {
    my ($self, $attrs, $text) = @_;

    # A regex that matches the portion of a variable reference that's the
    # array or hash index, separated out just because we want to use it in
    # several places in the following regex.
    my $index = '(?: \[.*\] | \{.*\} )?';

    # Check for things that we don't want to quote, and if we find any of
    # them, return the string with just a font change and no quoting.
    $text =~ m{
      ^\s*
      (?:
         ( [\'\`\"] ) .* \1                             # already quoted
       | \` .* \'                                       # `quoted'
       | \$+ [\#^]? \S $index                           # special ($^Foo, $")
       | [\$\@%&*]+ \#? [:\'\w]+ $index                 # plain var or func
       | [\$\@%&*]* [:\'\w]+ (?: -> )? \(\s*[^\s,]\s*\) # 0/1-arg func call
       | [+-]? ( \d[\d.]* | \.\d+ ) (?: [eE][+-]?\d+ )? # a number
       | 0x [a-fA-F\d]+                                 # a hex constant
      )
      \s*\z
     }xo && return $text;

    # If we didn't return, go ahead and quote the text.
    return $$self{opt_alt}
        ? "``$text''"
        : "$$self{LQUOTE}$text$$self{RQUOTE}";
}

# Links reduce to the text that we're given, wrapped in angle brackets if it's
# a URL.
sub cmd_l {
    my ($self, $attrs, $text) = @_;
    if ($$attrs{type} eq 'url') {
        if (not defined($$attrs{to}) or $$attrs{to} eq $text) {
            return "<$text>";
        } elsif ($$self{opt_nourls}) {
            return $text;
        } else {
            return "$text <$$attrs{to}>";
        }
    } else {
        return $text;
    }
}

##############################################################################
# Backwards compatibility
##############################################################################

# The old Pod::Text module did everything in a pod2text() function.  This
# tries to provide the same interface for legacy applications.
sub pod2text {
    my @args;

    # This is really ugly; I hate doing option parsing in the middle of a
    # module.  But the old Pod::Text module supported passing flags to its
    # entry function, so handle -a and -<number>.
    while ($_[0] =~ /^-/) {
        my $flag = shift;
        if    ($flag eq '-a')       { push (@args, alt => 1)    }
        elsif ($flag =~ /^-(\d+)$/) { push (@args, width => $1) }
        else {
            unshift (@_, $flag);
            last;
        }
    }

    # Now that we know what arguments we're using, create the parser.
    my $parser = Pod::Text->new (@args);

    # If two arguments were given, the second argument is going to be a file
    # handle.  That means we want to call parse_from_filehandle(), which means
    # we need to turn the first argument into a file handle.  Magic open will
    # handle the <&STDIN case automagically.
    if (defined $_[1]) {
        my @fhs = @_;
        local *IN;
        unless (open (IN, $fhs[0])) {
            croak ("Can't open $fhs[0] for reading: $!\n");
            return;
        }
        $fhs[0] = \*IN;
        $parser->output_fh ($fhs[1]);
        my $retval = $parser->parse_file ($fhs[0]);
        my $fh = $parser->output_fh ();
        close $fh;
        return $retval;
    } else {
        $parser->output_fh (\*STDOUT);
        return $parser->parse_file (@_);
    }
}

# Reset the underlying Pod::Simple object between calls to parse_from_file so
# that the same object can be reused to convert multiple pages.
sub parse_from_file {
    my $self = shift;
    $self->reinit;

    # Fake the old cutting option to Pod::Parser.  This fiddings with internal
    # Pod::Simple state and is quite ugly; we need a better approach.
    if (ref ($_[0]) eq 'HASH') {
        my $opts = shift @_;
        if (defined ($$opts{-cutting}) && !$$opts{-cutting}) {
            $$self{in_pod} = 1;
            $$self{last_was_blank} = 1;
        }
    }

    # Do the work.
    my $retval = $self->Pod::Simple::parse_from_file (@_);

    # Flush output, since Pod::Simple doesn't do this.  Ideally we should also
    # close the file descriptor if we had to open one, but we can't easily
    # figure this out.
    my $fh = $self->output_fh ();
    my $oldfh = select $fh;
    my $oldflush = $|;
    $| = 1;
    print $fh '';
    $| = $oldflush;
    select $oldfh;
    return $retval;
}

# Pod::Simple failed to provide this backward compatibility function, so
# implement it ourselves.  File handles are one of the inputs that
# parse_from_file supports.
sub parse_from_filehandle {
    my $self = shift;
    $self->parse_from_file (@_);
}

# Pod::Simple's parse_file doesn't set output_fh.  Wrap the call and do so
# ourself unless it was already set by the caller, since our documentation has
# always said that this should work.
sub parse_file {
    my ($self, $in) = @_;
    unless (defined $$self{output_fh}) {
        $self->output_fh (\*STDOUT);
    }
    return $self->SUPER::parse_file ($in);
}

##############################################################################
# Module return value and documentation
##############################################################################

1;
__END__

=for stopwords
alt stderr Allbery Sean Burke's Christiansen UTF-8 pre-Unicode utf8 nourls

=head1 NAME

Pod::Text - Convert POD data to formatted ASCII text

=head1 SYNOPSIS

    use Pod::Text;
    my $parser = Pod::Text->new (sentence => 0, width => 78);

    # Read POD from STDIN and write to STDOUT.
    $parser->parse_from_filehandle;

    # Read POD from file.pod and write to file.txt.
    $parser->parse_from_file ('file.pod', 'file.txt');

=head1 DESCRIPTION

Pod::Text is a module that can convert documentation in the POD format (the
preferred language for documenting Perl) into formatted ASCII.  It uses no
special formatting controls or codes whatsoever, and its output is therefore
suitable for nearly any device.

As a derived class from Pod::Simple, Pod::Text supports the same methods and
interfaces.  See L<Pod::Simple> for all the details; briefly, one creates a
new parser with C<< Pod::Text->new() >> and then normally calls parse_file().

new() can take options, in the form of key/value pairs, that control the
behavior of the parser.  The currently recognized options are:

=over 4

=item alt

If set to a true value, selects an alternate output format that, among other
things, uses a different heading style and marks C<=item> entries with a
colon in the left margin.  Defaults to false.

=item code

If set to a true value, the non-POD parts of the input file will be included
in the output.  Useful for viewing code documented with POD blocks with the
POD rendered and the code left intact.

=item errors

How to report errors.  C<die> says to throw an exception on any POD
formatting error.  C<stderr> says to report errors on standard error, but
not to throw an exception.  C<pod> says to include a POD ERRORS section
in the resulting documentation summarizing the errors.  C<none> ignores
POD errors entirely, as much as possible.

The default is C<output>.

=item indent

The number of spaces to indent regular text, and the default indentation for
C<=over> blocks.  Defaults to 4.

=item loose

If set to a true value, a blank line is printed after a C<=head1> heading.
If set to false (the default), no blank line is printed after C<=head1>,
although one is still printed after C<=head2>.  This is the default because
it's the expected formatting for manual pages; if you're formatting
arbitrary text documents, setting this to true may result in more pleasing
output.

=item margin

The width of the left margin in spaces.  Defaults to 0.  This is the margin
for all text, including headings, not the amount by which regular text is
indented; for the latter, see the I<indent> option.  To set the right
margin, see the I<width> option.

=item nourls

Normally, LZ<><> formatting codes with a URL but anchor text are formatted
to show both the anchor text and the URL.  In other words:

    L<foo|http://example.com/>

is formatted as:

    foo <http://example.com/>

This option, if set to a true value, suppresses the URL when anchor text
is given, so this example would be formatted as just C<foo>.  This can
produce less cluttered output in cases where the URLs are not particularly
important.

=item quotes

Sets the quote marks used to surround CE<lt>> text.  If the value is a
single character, it is used as both the left and right quote; if it is two
characters, the first character is used as the left quote and the second as
the right quoted; and if it is four characters, the first two are used as
the left quote and the second two as the right quote.

This may also be set to the special value C<none>, in which case no quote
marks are added around CE<lt>> text.

=item sentence

If set to a true value, Pod::Text will assume that each sentence ends in two
spaces, and will try to preserve that spacing.  If set to false, all
consecutive whitespace in non-verbatim paragraphs is compressed into a
single space.  Defaults to true.

=item stderr

Send error messages about invalid POD to standard error instead of
appending a POD ERRORS section to the generated output.  This is
equivalent to setting C<errors> to C<stderr> if C<errors> is not already
set.  It is supported for backward compatibility.

=item utf8

By default, Pod::Text uses the same output encoding as the input encoding
of the POD source (provided that Perl was built with PerlIO; otherwise, it
doesn't encode its output).  If this option is given, the output encoding
is forced to UTF-8.

Be aware that, when using this option, the input encoding of your POD
source must be properly declared unless it is US-ASCII or Latin-1.  POD
input without an C<=encoding> command will be assumed to be in Latin-1,
and if it's actually in UTF-8, the output will be double-encoded.  See
L<perlpod(1)> for more information on the C<=encoding> command.

=item width

The column at which to wrap text on the right-hand side.  Defaults to 76.

=back

The standard Pod::Simple method parse_file() takes one argument, the file or
file handle to read from, and writes output to standard output unless that
has been changed with the output_fh() method.  See L<Pod::Simple> for the
specific details and for other alternative interfaces.

=head1 DIAGNOSTICS

=over 4

=item Bizarre space in item

=item Item called without tag

(W) Something has gone wrong in internal C<=item> processing.  These
messages indicate a bug in Pod::Text; you should never see them.

=item Can't open %s for reading: %s

(F) Pod::Text was invoked via the compatibility mode pod2text() interface
and the input file it was given could not be opened.

=item Invalid errors setting "%s"

(F) The C<errors> parameter to the constructor was set to an unknown value.

=item Invalid quote specification "%s"

(F) The quote specification given (the C<quotes> option to the
constructor) was invalid.  A quote specification must be one, two, or four
characters long.

=item POD document had syntax errors

(F) The POD document being formatted had syntax errors and the C<errors>
option was set to C<die>.

=back

=head1 BUGS

Encoding handling assumes that PerlIO is available and does not work
properly if it isn't.  The C<utf8> option is therefore not supported
unless Perl is built with PerlIO support.

=head1 CAVEATS

If Pod::Text is given the C<utf8> option, the encoding of its output file
handle will be forced to UTF-8 if possible, overriding any existing
encoding.  This will be done even if the file handle is not created by
Pod::Text and was passed in from outside.  This maintains consistency
regardless of PERL_UNICODE and other settings.

If the C<utf8> option is not given, the encoding of its output file handle
will be forced to the detected encoding of the input POD, which preserves
whatever the input text is.  This ensures backward compatibility with
earlier, pre-Unicode versions of this module, without large numbers of
Perl warnings.

This is not ideal, but it seems to be the best compromise.  If it doesn't
work for you, please let me know the details of how it broke.

=head1 NOTES

This is a replacement for an earlier Pod::Text module written by Tom
Christiansen.  It has a revamped interface, since it now uses Pod::Simple,
but an interface roughly compatible with the old Pod::Text::pod2text()
function is still available.  Please change to the new calling convention,
though.

The original Pod::Text contained code to do formatting via termcap
sequences, although it wasn't turned on by default and it was problematic to
get it to work at all.  This rewrite doesn't even try to do that, but a
subclass of it does.  Look for L<Pod::Text::Termcap>.

=head1 SEE ALSO

L<Pod::Simple>, L<Pod::Text::Termcap>, L<perlpod(1)>, L<pod2text(1)>

The current version of this module is always available from its web site at
L<http://www.eyrie.org/~eagle/software/podlators/>.  It is also part of the
Perl core distribution as of 5.6.0.

=head1 AUTHOR

Russ Allbery <rra@stanford.edu>, based I<very> heavily on the original
Pod::Text by Tom Christiansen <tchrist@mox.perl.com> and its conversion to
Pod::Parser by Brad Appleton <bradapp@enteract.com>.  Sean Burke's initial
conversion of Pod::Man to use Pod::Simple provided much-needed guidance on
how to use Pod::Simple.

=head1 COPYRIGHT AND LICENSE

Copyright 1999, 2000, 2001, 2002, 2004, 2006, 2008, 2009, 2012, 2013 Russ
Allbery <rra@stanford.edu>.

This program is free software; you may redistribute it and/or modify it
under the same terms as Perl itself.

=cut