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   1  # Pod::PlainText -- Convert POD data to formatted ASCII text.
   2  # $Id: Text.pm,v 2.1 1999/09/20 11:53:33 eagle Exp $
   3  #
   4  # Copyright 1999-2000 by Russ Allbery <rra@stanford.edu>
   5  #
   6  # This program is free software; you can redistribute it and/or modify it
   7  # under the same terms as Perl itself.
   8  #
   9  # This module is intended to be a replacement for Pod::Text, and attempts to
  10  # match its output except for some specific circumstances where other
  11  # decisions seemed to produce better output.  It uses Pod::Parser and is
  12  # designed to be very easy to subclass.
  13  
  14  ############################################################################
  15  # Modules and declarations
  16  ############################################################################
  17  
  18  package Pod::PlainText;
  19  
  20  require 5.005;
  21  
  22  use Carp qw(carp croak);
  23  use Pod::Select ();
  24  
  25  use strict;
  26  use vars qw(@ISA %ESCAPES $VERSION);
  27  
  28  # We inherit from Pod::Select instead of Pod::Parser so that we can be used
  29  # by Pod::Usage.
  30  @ISA = qw(Pod::Select);
  31  
  32  $VERSION = '2.02';
  33  
  34  
  35  ############################################################################
  36  # Table of supported E<> escapes
  37  ############################################################################
  38  
  39  # This table is taken near verbatim from Pod::PlainText in Pod::Parser,
  40  # which got it near verbatim from the original Pod::Text.  It is therefore
  41  # credited to Tom Christiansen, and I'm glad I didn't have to write it.  :)
  42  %ESCAPES = (
  43      'amp'       =>    '&',      # ampersand
  44      'lt'        =>    '<',      # left chevron, less-than
  45      'gt'        =>    '>',      # right chevron, greater-than
  46      'quot'      =>    '"',      # double quote
  47  
  48      "Aacute"    =>    "\xC1",   # capital A, acute accent
  49      "aacute"    =>    "\xE1",   # small a, acute accent
  50      "Acirc"     =>    "\xC2",   # capital A, circumflex accent
  51      "acirc"     =>    "\xE2",   # small a, circumflex accent
  52      "AElig"     =>    "\xC6",   # capital AE diphthong (ligature)
  53      "aelig"     =>    "\xE6",   # small ae diphthong (ligature)
  54      "Agrave"    =>    "\xC0",   # capital A, grave accent
  55      "agrave"    =>    "\xE0",   # small a, grave accent
  56      "Aring"     =>    "\xC5",   # capital A, ring
  57      "aring"     =>    "\xE5",   # small a, ring
  58      "Atilde"    =>    "\xC3",   # capital A, tilde
  59      "atilde"    =>    "\xE3",   # small a, tilde
  60      "Auml"      =>    "\xC4",   # capital A, dieresis or umlaut mark
  61      "auml"      =>    "\xE4",   # small a, dieresis or umlaut mark
  62      "Ccedil"    =>    "\xC7",   # capital C, cedilla
  63      "ccedil"    =>    "\xE7",   # small c, cedilla
  64      "Eacute"    =>    "\xC9",   # capital E, acute accent
  65      "eacute"    =>    "\xE9",   # small e, acute accent
  66      "Ecirc"     =>    "\xCA",   # capital E, circumflex accent
  67      "ecirc"     =>    "\xEA",   # small e, circumflex accent
  68      "Egrave"    =>    "\xC8",   # capital E, grave accent
  69      "egrave"    =>    "\xE8",   # small e, grave accent
  70      "ETH"       =>    "\xD0",   # capital Eth, Icelandic
  71      "eth"       =>    "\xF0",   # small eth, Icelandic
  72      "Euml"      =>    "\xCB",   # capital E, dieresis or umlaut mark
  73      "euml"      =>    "\xEB",   # small e, dieresis or umlaut mark
  74      "Iacute"    =>    "\xCD",   # capital I, acute accent
  75      "iacute"    =>    "\xED",   # small i, acute accent
  76      "Icirc"     =>    "\xCE",   # capital I, circumflex accent
  77      "icirc"     =>    "\xEE",   # small i, circumflex accent
  78      "Igrave"    =>    "\xCD",   # capital I, grave accent
  79      "igrave"    =>    "\xED",   # small i, grave accent
  80      "Iuml"      =>    "\xCF",   # capital I, dieresis or umlaut mark
  81      "iuml"      =>    "\xEF",   # small i, dieresis or umlaut mark
  82      "Ntilde"    =>    "\xD1",   # capital N, tilde
  83      "ntilde"    =>    "\xF1",   # small n, tilde
  84      "Oacute"    =>    "\xD3",   # capital O, acute accent
  85      "oacute"    =>    "\xF3",   # small o, acute accent
  86      "Ocirc"     =>    "\xD4",   # capital O, circumflex accent
  87      "ocirc"     =>    "\xF4",   # small o, circumflex accent
  88      "Ograve"    =>    "\xD2",   # capital O, grave accent
  89      "ograve"    =>    "\xF2",   # small o, grave accent
  90      "Oslash"    =>    "\xD8",   # capital O, slash
  91      "oslash"    =>    "\xF8",   # small o, slash
  92      "Otilde"    =>    "\xD5",   # capital O, tilde
  93      "otilde"    =>    "\xF5",   # small o, tilde
  94      "Ouml"      =>    "\xD6",   # capital O, dieresis or umlaut mark
  95      "ouml"      =>    "\xF6",   # small o, dieresis or umlaut mark
  96      "szlig"     =>    "\xDF",   # small sharp s, German (sz ligature)
  97      "THORN"     =>    "\xDE",   # capital THORN, Icelandic
  98      "thorn"     =>    "\xFE",   # small thorn, Icelandic
  99      "Uacute"    =>    "\xDA",   # capital U, acute accent
 100      "uacute"    =>    "\xFA",   # small u, acute accent
 101      "Ucirc"     =>    "\xDB",   # capital U, circumflex accent
 102      "ucirc"     =>    "\xFB",   # small u, circumflex accent
 103      "Ugrave"    =>    "\xD9",   # capital U, grave accent
 104      "ugrave"    =>    "\xF9",   # small u, grave accent
 105      "Uuml"      =>    "\xDC",   # capital U, dieresis or umlaut mark
 106      "uuml"      =>    "\xFC",   # small u, dieresis or umlaut mark
 107      "Yacute"    =>    "\xDD",   # capital Y, acute accent
 108      "yacute"    =>    "\xFD",   # small y, acute accent
 109      "yuml"      =>    "\xFF",   # small y, dieresis or umlaut mark
 110  
 111      "lchevron"  =>    "\xAB",   # left chevron (double less than)
 112      "rchevron"  =>    "\xBB",   # right chevron (double greater than)
 113  );
 114  
 115  
 116  ############################################################################
 117  # Initialization
 118  ############################################################################
 119  
 120  # Initialize the object.  Must be sure to call our parent initializer.
 121  sub initialize {
 122      my $self = shift;
 123  
 124      $$self{alt}      = 0  unless defined $$self{alt};
 125      $$self{indent}   = 4  unless defined $$self{indent};
 126      $$self{loose}    = 0  unless defined $$self{loose};
 127      $$self{sentence} = 0  unless defined $$self{sentence};
 128      $$self{width}    = 76 unless defined $$self{width};
 129  
 130      $$self{INDENTS}  = [];              # Stack of indentations.
 131      $$self{MARGIN}   = $$self{indent};  # Current left margin in spaces.
 132  
 133      $self->SUPER::initialize;
 134  }
 135  
 136  
 137  ############################################################################
 138  # Core overrides
 139  ############################################################################
 140  
 141  # Called for each command paragraph.  Gets the command, the associated
 142  # paragraph, the line number, and a Pod::Paragraph object.  Just dispatches
 143  # the command to a method named the same as the command.  =cut is handled
 144  # internally by Pod::Parser.
 145  sub command {
 146      my $self = shift;
 147      my $command = shift;
 148      return if $command eq 'pod';
 149      return if ($$self{EXCLUDE} && $command ne 'end');
 150      $self->item ("\n") if defined $$self{ITEM};
 151      $command = 'cmd_' . $command;
 152      $self->$command (@_);
 153  }
 154  
 155  # Called for a verbatim paragraph.  Gets the paragraph, the line number, and
 156  # a Pod::Paragraph object.  Just output it verbatim, but with tabs converted
 157  # to spaces.
 158  sub verbatim {
 159      my $self = shift;
 160      return if $$self{EXCLUDE};
 161      $self->item if defined $$self{ITEM};
 162      local $_ = shift;
 163      return if /^\s*$/;
 164      s/^(\s*\S+)/(' ' x $$self{MARGIN}) . $1/gme;
 165      $self->output ($_);
 166  }
 167  
 168  # Called for a regular text block.  Gets the paragraph, the line number, and
 169  # a Pod::Paragraph object.  Perform interpolation and output the results.
 170  sub textblock {
 171      my $self = shift;
 172      return if $$self{EXCLUDE};
 173      $self->output ($_[0]), return if $$self{VERBATIM};
 174      local $_ = shift;
 175      my $line = shift;
 176  
 177      # Perform a little magic to collapse multiple L<> references.  This is
 178      # here mostly for backwards-compatibility.  We'll just rewrite the whole
 179      # thing into actual text at this part, bypassing the whole internal
 180      # sequence parsing thing.
 181      s{
 182          (
 183            L<                    # A link of the form L</something>.
 184                /
 185                (
 186                    [:\w]+        # The item has to be a simple word...
 187                    (\(\))?       # ...or simple function.
 188                )
 189            >
 190            (
 191                ,?\s+(and\s+)?    # Allow lots of them, conjuncted.
 192                L<  
 193                    /
 194                    (
 195                        [:\w]+
 196                        (\(\))?
 197                    )
 198                >
 199            )+
 200          )
 201      } {
 202          local $_ = $1;
 203          s%L</([^>]+)>%$1%g;
 204          my @items = split /(?:,?\s+(?:and\s+)?)/;
 205          my $string = "the ";
 206          my $i;
 207          for ($i = 0; $i < @items; $i++) {
 208              $string .= $items[$i];
 209              $string .= ", " if @items > 2 && $i != $#items;
 210              $string .= " and " if ($i == $#items - 1);
 211          }
 212          $string .= " entries elsewhere in this document";
 213          $string;
 214      }gex;
 215  
 216      # Now actually interpolate and output the paragraph.
 217      $_ = $self->interpolate ($_, $line);
 218      s/\s+$/\n/;
 219      if (defined $$self{ITEM}) {
 220          $self->item ($_ . "\n");
 221      } else {
 222          $self->output ($self->reformat ($_ . "\n"));
 223      }
 224  }
 225  
 226  # Called for an interior sequence.  Gets the command, argument, and a
 227  # Pod::InteriorSequence object and is expected to return the resulting text.
 228  # Calls code, bold, italic, file, and link to handle those types of
 229  # sequences, and handles S<>, E<>, X<>, and Z<> directly.
 230  sub interior_sequence {
 231      my $self = shift;
 232      my $command = shift;
 233      local $_ = shift;
 234      return '' if ($command eq 'X' || $command eq 'Z');
 235  
 236      # Expand escapes into the actual character now, carping if invalid.
 237      if ($command eq 'E') {
 238          return $ESCAPES{$_} if defined $ESCAPES{$_};
 239          carp "Unknown escape: E<$_>";
 240          return "E<$_>";
 241      }
 242  
 243      # For all the other sequences, empty content produces no output.
 244      return if $_ eq '';
 245  
 246      # For S<>, compress all internal whitespace and then map spaces to \01.
 247      # When we output the text, we'll map this back.
 248      if ($command eq 'S') {
 249          s/\s{2,}/ /g;
 250          tr/ /\01/;
 251          return $_;
 252      }
 253  
 254      # Anything else needs to get dispatched to another method.
 255      if    ($command eq 'B') { return $self->seq_b ($_) }
 256      elsif ($command eq 'C') { return $self->seq_c ($_) }
 257      elsif ($command eq 'F') { return $self->seq_f ($_) }
 258      elsif ($command eq 'I') { return $self->seq_i ($_) }
 259      elsif ($command eq 'L') { return $self->seq_l ($_) }
 260      else { carp "Unknown sequence $command<$_>" }
 261  }
 262  
 263  # Called for each paragraph that's actually part of the POD.  We take
 264  # advantage of this opportunity to untabify the input.
 265  sub preprocess_paragraph {
 266      my $self = shift;
 267      local $_ = shift;
 268      1 while s/^(.*?)(\t+)/$1 . ' ' x (length ($2) * 8 - length ($1) % 8)/me;
 269      $_;
 270  }
 271  
 272  
 273  ############################################################################
 274  # Command paragraphs
 275  ############################################################################
 276  
 277  # All command paragraphs take the paragraph and the line number.
 278  
 279  # First level heading.
 280  sub cmd_head1 {
 281      my $self = shift;
 282      local $_ = shift;
 283      s/\s+$//;
 284      $_ = $self->interpolate ($_, shift);
 285      if ($$self{alt}) {
 286          $self->output ("\n==== $_ ====\n\n");
 287      } else {
 288          $_ .= "\n" if $$self{loose};
 289          $self->output ($_ . "\n");
 290      }
 291  }
 292  
 293  # Second level heading.
 294  sub cmd_head2 {
 295      my $self = shift;
 296      local $_ = shift;
 297      s/\s+$//;
 298      $_ = $self->interpolate ($_, shift);
 299      if ($$self{alt}) {
 300          $self->output ("\n==   $_   ==\n\n");
 301      } else {
 302          $self->output (' ' x ($$self{indent} / 2) . $_ . "\n\n");
 303      }
 304  }
 305  
 306  # third level heading - not strictly perlpodspec compliant
 307  sub cmd_head3 {
 308      my $self = shift;
 309      local $_ = shift;
 310      s/\s+$//;
 311      $_ = $self->interpolate ($_, shift);
 312      if ($$self{alt}) {
 313          $self->output ("\n= $_ =\n");
 314      } else {
 315          $self->output (' ' x ($$self{indent}) . $_ . "\n");
 316      }
 317  }
 318  
 319  # fourth level heading - not strictly perlpodspec compliant
 320  # just like head3
 321  *cmd_head4 = \&cmd_head3;
 322  
 323  # Start a list.
 324  sub cmd_over {
 325      my $self = shift;
 326      local $_ = shift;
 327      unless (/^[-+]?\d+\s+$/) { $_ = $$self{indent} }
 328      push (@{ $$self{INDENTS} }, $$self{MARGIN});
 329      $$self{MARGIN} += ($_ + 0);
 330  }
 331  
 332  # End a list.
 333  sub cmd_back {
 334      my $self = shift;
 335      $$self{MARGIN} = pop @{ $$self{INDENTS} };
 336      unless (defined $$self{MARGIN}) {
 337          carp "Unmatched =back";
 338          $$self{MARGIN} = $$self{indent};
 339      }
 340  }
 341  
 342  # An individual list item.
 343  sub cmd_item {
 344      my $self = shift;
 345      if (defined $$self{ITEM}) { $self->item }
 346      local $_ = shift;
 347      s/\s+$//;
 348      $$self{ITEM} = $self->interpolate ($_);
 349  }
 350  
 351  # Begin a block for a particular translator.  Setting VERBATIM triggers
 352  # special handling in textblock().
 353  sub cmd_begin {
 354      my $self = shift;
 355      local $_ = shift;
 356      my ($kind) = /^(\S+)/ or return;
 357      if ($kind eq 'text') {
 358          $$self{VERBATIM} = 1;
 359      } else {
 360          $$self{EXCLUDE} = 1;
 361      }
 362  }
 363  
 364  # End a block for a particular translator.  We assume that all =begin/=end
 365  # pairs are properly closed.
 366  sub cmd_end {
 367      my $self = shift;
 368      $$self{EXCLUDE} = 0;
 369      $$self{VERBATIM} = 0;
 370  }    
 371  
 372  # One paragraph for a particular translator.  Ignore it unless it's intended
 373  # for text, in which case we treat it as a verbatim text block.
 374  sub cmd_for {
 375      my $self = shift;
 376      local $_ = shift;
 377      my $line = shift;
 378      return unless s/^text\b[ \t]*\n?//;
 379      $self->verbatim ($_, $line);
 380  }
 381  
 382  
 383  ############################################################################
 384  # Interior sequences
 385  ############################################################################
 386  
 387  # The simple formatting ones.  These are here mostly so that subclasses can
 388  # override them and do more complicated things.
 389  sub seq_b { return $_[0]{alt} ? "``$_[1]''" : $_[1] }
 390  sub seq_c { return $_[0]{alt} ? "``$_[1]''" : "`$_[1]'" }
 391  sub seq_f { return $_[0]{alt} ? "\"$_[1]\"" : $_[1] }
 392  sub seq_i { return '*' . $_[1] . '*' }
 393  
 394  # The complicated one.  Handle links.  Since this is plain text, we can't
 395  # actually make any real links, so this is all to figure out what text we
 396  # print out.
 397  sub seq_l {
 398      my $self = shift;
 399      local $_ = shift;
 400  
 401      # Smash whitespace in case we were split across multiple lines.
 402      s/\s+/ /g;
 403  
 404      # If we were given any explicit text, just output it.
 405      if (/^([^|]+)\|/) { return $1 }
 406  
 407      # Okay, leading and trailing whitespace isn't important; get rid of it.
 408      s/^\s+//;
 409      s/\s+$//;
 410  
 411      # Default to using the whole content of the link entry as a section
 412      # name.  Note that L<manpage/> forces a manpage interpretation, as does
 413      # something looking like L<manpage(section)>.  The latter is an
 414      # enhancement over the original Pod::Text.
 415      my ($manpage, $section) = ('', $_);
 416      if (/^(?:https?|ftp|news):/) {
 417          # a URL
 418          return $_;
 419      } elsif (/^"\s*(.*?)\s*"$/) {
 420          $section = '"' . $1 . '"';
 421      } elsif (m/^[-:.\w]+(?:\(\S+\))?$/) {
 422          ($manpage, $section) = ($_, '');
 423      } elsif (m%/%) {
 424          ($manpage, $section) = split (/\s*\/\s*/, $_, 2);
 425      }
 426  
 427      my $text = '';
 428      # Now build the actual output text.
 429      if (!length $section) {
 430          $text = "the $manpage manpage" if length $manpage;
 431      } elsif ($section =~ /^[:\w]+(?:\(\))?/) {
 432          $text .= 'the ' . $section . ' entry';
 433          $text .= (length $manpage) ? " in the $manpage manpage"
 434                                     : " elsewhere in this document";
 435      } else {
 436          $section =~ s/^\"\s*//;
 437          $section =~ s/\s*\"$//;
 438          $text .= 'the section on "' . $section . '"';
 439          $text .= " in the $manpage manpage" if length $manpage;
 440      }
 441      $text;
 442  }
 443  
 444  
 445  ############################################################################
 446  # List handling
 447  ############################################################################
 448  
 449  # This method is called whenever an =item command is complete (in other
 450  # words, we've seen its associated paragraph or know for certain that it
 451  # doesn't have one).  It gets the paragraph associated with the item as an
 452  # argument.  If that argument is empty, just output the item tag; if it
 453  # contains a newline, output the item tag followed by the newline.
 454  # Otherwise, see if there's enough room for us to output the item tag in the
 455  # margin of the text or if we have to put it on a separate line.
 456  sub item {
 457      my $self = shift;
 458      local $_ = shift;
 459      my $tag = $$self{ITEM};
 460      unless (defined $tag) {
 461          carp "item called without tag";
 462          return;
 463      }
 464      undef $$self{ITEM};
 465      my $indent = $$self{INDENTS}[-1];
 466      unless (defined $indent) { $indent = $$self{indent} }
 467      my $space = ' ' x $indent;
 468      $space =~ s/^ /:/ if $$self{alt};
 469      if (!$_ || /^\s+$/ || ($$self{MARGIN} - $indent < length ($tag) + 1)) {
 470          my $margin = $$self{MARGIN};
 471          $$self{MARGIN} = $indent;
 472          my $output = $self->reformat ($tag);
 473          $output =~ s/\n*$/\n/;
 474          $self->output ($output);
 475          $$self{MARGIN} = $margin;
 476          $self->output ($self->reformat ($_)) if /\S/;
 477      } else {
 478          $_ = $self->reformat ($_);
 479          s/^ /:/ if ($$self{alt} && $indent > 0);
 480          my $tagspace = ' ' x length $tag;
 481          s/^($space)$tagspace/$1$tag/ or warn "Bizarre space in item";
 482          $self->output ($_);
 483      }
 484  }
 485  
 486  
 487  ############################################################################
 488  # Output formatting
 489  ############################################################################
 490  
 491  # Wrap a line, indenting by the current left margin.  We can't use
 492  # Text::Wrap because it plays games with tabs.  We can't use formline, even
 493  # though we'd really like to, because it screws up non-printing characters.
 494  # So we have to do the wrapping ourselves.
 495  sub wrap {
 496      my $self = shift;
 497      local $_ = shift;
 498      my $output = '';
 499      my $spaces = ' ' x $$self{MARGIN};
 500      my $width = $$self{width} - $$self{MARGIN};
 501      while (length > $width) {
 502          if (s/^([^\n]{0,$width})\s+// || s/^([^\n]{$width})//) {
 503              $output .= $spaces . $1 . "\n";
 504          } else {
 505              last;
 506          }
 507      }
 508      $output .= $spaces . $_;
 509      $output =~ s/\s+$/\n\n/;
 510      $output;
 511  }
 512  
 513  # Reformat a paragraph of text for the current margin.  Takes the text to
 514  # reformat and returns the formatted text.
 515  sub reformat {
 516      my $self = shift;
 517      local $_ = shift;
 518  
 519      # If we're trying to preserve two spaces after sentences, do some
 520      # munging to support that.  Otherwise, smash all repeated whitespace.
 521      if ($$self{sentence}) {
 522          s/ +$//mg;
 523          s/\.\n/. \n/g;
 524          s/\n/ /g;
 525          s/   +/  /g;
 526      } else {
 527          s/\s+/ /g;
 528      }
 529      $self->wrap ($_);
 530  }
 531  
 532  # Output text to the output device.
 533  sub output { $_[1] =~ tr/\01/ /; print { $_[0]->output_handle } $_[1] }
 534  
 535  
 536  ############################################################################
 537  # Backwards compatibility
 538  ############################################################################
 539  
 540  # The old Pod::Text module did everything in a pod2text() function.  This
 541  # tries to provide the same interface for legacy applications.
 542  sub pod2text {
 543      my @args;
 544  
 545      # This is really ugly; I hate doing option parsing in the middle of a
 546      # module.  But the old Pod::Text module supported passing flags to its
 547      # entry function, so handle -a and -<number>.
 548      while ($_[0] =~ /^-/) {
 549          my $flag = shift;
 550          if    ($flag eq '-a')       { push (@args, alt => 1)    }
 551          elsif ($flag =~ /^-(\d+)$/) { push (@args, width => $1) }
 552          else {
 553              unshift (@_, $flag);
 554              last;
 555          }
 556      }
 557  
 558      # Now that we know what arguments we're using, create the parser.
 559      my $parser = Pod::PlainText->new (@args);
 560  
 561      # If two arguments were given, the second argument is going to be a file
 562      # handle.  That means we want to call parse_from_filehandle(), which
 563      # means we need to turn the first argument into a file handle.  Magic
 564      # open will handle the <&STDIN case automagically.
 565      if (defined $_[1]) {
 566          local *IN;
 567          unless (open (IN, $_[0])) {
 568              croak ("Can't open $_[0] for reading: $!\n");
 569              return;
 570          }
 571          $_[0] = \*IN;
 572          return $parser->parse_from_filehandle (@_);
 573      } else {
 574          return $parser->parse_from_file (@_);
 575      }
 576  }
 577  
 578  
 579  ############################################################################
 580  # Module return value and documentation
 581  ############################################################################
 582  
 583  1;
 584  __END__
 585  
 586  =head1 NAME
 587  
 588  Pod::PlainText - Convert POD data to formatted ASCII text
 589  
 590  =head1 SYNOPSIS
 591  
 592      use Pod::PlainText;
 593      my $parser = Pod::PlainText->new (sentence => 0, width => 78);
 594  
 595      # Read POD from STDIN and write to STDOUT.
 596      $parser->parse_from_filehandle;
 597  
 598      # Read POD from file.pod and write to file.txt.
 599      $parser->parse_from_file ('file.pod', 'file.txt');
 600  
 601  =head1 DESCRIPTION
 602  
 603  Pod::PlainText is a module that can convert documentation in the POD format (the
 604  preferred language for documenting Perl) into formatted ASCII.  It uses no
 605  special formatting controls or codes whatsoever, and its output is therefore
 606  suitable for nearly any device.
 607  
 608  As a derived class from Pod::Parser, Pod::PlainText supports the same methods and
 609  interfaces.  See L<Pod::Parser> for all the details; briefly, one creates a
 610  new parser with C<Pod::PlainText-E<gt>new()> and then calls either
 611  parse_from_filehandle() or parse_from_file().
 612  
 613  new() can take options, in the form of key/value pairs, that control the
 614  behavior of the parser.  The currently recognized options are:
 615  
 616  =over 4
 617  
 618  =item alt
 619  
 620  If set to a true value, selects an alternate output format that, among other
 621  things, uses a different heading style and marks C<=item> entries with a
 622  colon in the left margin.  Defaults to false.
 623  
 624  =item indent
 625  
 626  The number of spaces to indent regular text, and the default indentation for
 627  C<=over> blocks.  Defaults to 4.
 628  
 629  =item loose
 630  
 631  If set to a true value, a blank line is printed after a C<=head1> heading.
 632  If set to false (the default), no blank line is printed after C<=head1>,
 633  although one is still printed after C<=head2>.  This is the default because
 634  it's the expected formatting for manual pages; if you're formatting
 635  arbitrary text documents, setting this to true may result in more pleasing
 636  output.
 637  
 638  =item sentence
 639  
 640  If set to a true value, Pod::PlainText will assume that each sentence ends in two
 641  spaces, and will try to preserve that spacing.  If set to false, all
 642  consecutive whitespace in non-verbatim paragraphs is compressed into a
 643  single space.  Defaults to true.
 644  
 645  =item width
 646  
 647  The column at which to wrap text on the right-hand side.  Defaults to 76.
 648  
 649  =back
 650  
 651  The standard Pod::Parser method parse_from_filehandle() takes up to two
 652  arguments, the first being the file handle to read POD from and the second
 653  being the file handle to write the formatted output to.  The first defaults
 654  to STDIN if not given, and the second defaults to STDOUT.  The method
 655  parse_from_file() is almost identical, except that its two arguments are the
 656  input and output disk files instead.  See L<Pod::Parser> for the specific
 657  details.
 658  
 659  =head1 DIAGNOSTICS
 660  
 661  =over 4
 662  
 663  =item Bizarre space in item
 664  
 665  (W) Something has gone wrong in internal C<=item> processing.  This message
 666  indicates a bug in Pod::PlainText; you should never see it.
 667  
 668  =item Can't open %s for reading: %s
 669  
 670  (F) Pod::PlainText was invoked via the compatibility mode pod2text() interface
 671  and the input file it was given could not be opened.
 672  
 673  =item Unknown escape: %s
 674  
 675  (W) The POD source contained an C<EE<lt>E<gt>> escape that Pod::PlainText didn't
 676  know about.
 677  
 678  =item Unknown sequence: %s
 679  
 680  (W) The POD source contained a non-standard internal sequence (something of
 681  the form C<XE<lt>E<gt>>) that Pod::PlainText didn't know about.
 682  
 683  =item Unmatched =back
 684  
 685  (W) Pod::PlainText encountered a C<=back> command that didn't correspond to an
 686  C<=over> command.
 687  
 688  =back
 689  
 690  =head1 RESTRICTIONS
 691  
 692  Embedded Ctrl-As (octal 001) in the input will be mapped to spaces on
 693  output, due to an internal implementation detail.
 694  
 695  =head1 NOTES
 696  
 697  This is a replacement for an earlier Pod::Text module written by Tom
 698  Christiansen.  It has a revamped interface, since it now uses Pod::Parser,
 699  but an interface roughly compatible with the old Pod::Text::pod2text()
 700  function is still available.  Please change to the new calling convention,
 701  though.
 702  
 703  The original Pod::Text contained code to do formatting via termcap
 704  sequences, although it wasn't turned on by default and it was problematic to
 705  get it to work at all.  This rewrite doesn't even try to do that, but a
 706  subclass of it does.  Look for L<Pod::Text::Termcap|Pod::Text::Termcap>.
 707  
 708  =head1 SEE ALSO
 709  
 710  L<Pod::Parser|Pod::Parser>, L<Pod::Text::Termcap|Pod::Text::Termcap>,
 711  pod2text(1)
 712  
 713  =head1 AUTHOR
 714  
 715  Please report bugs using L<http://rt.cpan.org>.
 716  
 717  Russ Allbery E<lt>rra@stanford.eduE<gt>, based I<very> heavily on the
 718  original Pod::Text by Tom Christiansen E<lt>tchrist@mox.perl.comE<gt> and
 719  its conversion to Pod::Parser by Brad Appleton
 720  E<lt>bradapp@enteract.comE<gt>.
 721  
 722  =cut