Pod::Escapes

Section: Perl Programmers Reference Guide (3perl)
Updated: 2019-04-20
Page Index

NAME

Pod::Escapes - for resolving Pod E<...> sequences

SYNOPSIS

  use Pod::Escapes qw(e2char);
  ...la la la, parsing POD, la la la...
  $text = e2char($e_node->label);
  unless(defined $text) {
    print "Unknown E sequence \"", $e_node->label, "\"!";
  }
  ...else print/interpolate $text...

DESCRIPTION

This module provides things that are useful in decoding Pod E<...> sequences. Presumably, it should be used only by Pod parsers and/or formatters.

By default, Pod::Escapes exports none of its symbols. But you can request any of them to be exported. Either request them individually, as with "use Pod::Escapes qw(symbolname symbolname2...);", or you can do "use Pod::Escapes qw(:ALL);" to get all exportable symbols.

GOODIES

e2char($e_content): Given a name or number that could appear in a "E<name_or_num>" sequence, this returns the string that it stands for. For example, "e2char('sol')", "e2char('47')", "e2char('0x2F')", and "e2char('057')" all return ``/'', because "E<sol>", "E<47>", "E<0x2f>", and "E<057>", all mean ``/''. If the name has no known value (as with a name of ``qacute'') or is syntactically invalid (as with a name of ``1/4''), this returns undef.
e2charnum($e_content): Given a name or number that could appear in a "E<name_or_num>" sequence, this returns the number of the Unicode character that this stands for. For example, "e2char('sol')", "e2char('47')", "e2char('0x2F')", and "e2char('057')" all return 47, because "E<sol>", "E<47>", "E<0x2f>", and "E<057>", all mean ``/'', whose Unicode number is 47. If the name has no known value (as with a name of ``qacute'') or is syntactically invalid (as with a name of ``1/4''), this returns undef.
$Name2character{name}: Maps from names (as in "E<name>") like ``eacute'' or ``sol'' to the string that each stands for. Note that this does not include numerics (like ``64'' or ``x981c''). Under old Perl versions (before 5.7) you get a ``?'' in place of characters whose Unicode value is over 255.
$Name2character_number{name}: Maps from names (as in "E<name>") like ``eacute'' or ``sol'' to the Unicode value that each stands for. For example, $Name2character_number{'eacute'} is 201, and $Name2character_number{'eacute'} is 8364. You get the correct Unicode value, regardless of the version of Perl you're using --- which differs from %Name2character's behavior under pre-5.7 Perls.
Note that this hash does not include numerics (like ``64'' or ``x981c'').
$Latin1Code_to_fallback{integer}: For numbers in the range 160 (0x00A0) to 255 (0x00FF), this maps from the character code for a Latin-1 character (like 233 for lowercase e-acute) to the US-ASCII character that best aproximates it (like ``e''). You may find this useful if you are rendering POD in a format that you think deals well only with US-ASCII characters.
$Latin1Char_to_fallback{character}: Just as above, but maps from characters (like ``\xE9'', lowercase e-acute) to characters (like ``e'').
$Code2USASCII{integer}: This maps from US-ASCII codes (like 32) to the corresponding character (like space, for 32). Only characters 32 to 126 are defined. This is meant for use by "e2char($x)" when it senses that it's running on a non-ASCII platform (where chr(32) doesn't get you a space --- but $Code2USASCII{32} will). It's documented here just in case you might find it useful.

CAVEATS

On Perl versions before 5.7, Unicode characters with a value over 255 (like lambda or emdash) can't be conveyed. This module does work under such early Perl versions, but in the place of each such character, you get a ``?''. Latin-1 characters (characters 160-255) are unaffected.

Under EBCDIC platforms, "e2char($n)" may not always be the same as "chr(e2charnum($n))", and ditto for $Name2character{$name} and "chr($Name2character_number{$name})", because the strings are returned as native, and the numbers are returned as Unicode. However, for Perls starting with v5.8, "e2char($n)" is the same as "chr(utf8::unicode_to_native(e2charnum($n)))", and ditto for $Name2character{$name} and "chr(utf8::unicode_to_native($Name2character_number{$name}))".

REPOSITORY

<https://github.com/neilbowers/Pod-Escapes>

COPYRIGHT AND DISCLAIMERS

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

This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.

Portions of the data tables in this module are derived from the entity declarations in the W3C XHTML specification.

Currently (October 2001), that's these three:

 http://www.w3.org/TR/xhtml1/DTD/xhtml-lat1.ent
 http://www.w3.org/TR/xhtml1/DTD/xhtml-special.ent
 http://www.w3.org/TR/xhtml1/DTD/xhtml-symbol.ent

AUTHOR

Sean M. Burke "sburke@cpan.org"

Now being maintained by Neil Bowers <neilb@cpan.org>