Pod::Elemental::Selectors - predicates for selecting elements


version 0.103006


Pod::Elemental::Selectors provides a number of routines to check for Pod::Elemental paragraphs with given qualities.


This library should run on perls released even a long time ago. It should work on any version of perl released in the last five years.

Although it may work on older versions of perl, no guarantee is made that the minimum required version will not be increased. The version may be increased for any reason, and there is no promise that patches will be accepted to lower the minimum required perl.


Selectors are predicates: they examine paragraphs and return either true or false. All the selectors have (by default) names like: s_whatever. They expect zero or more parameters to affect the selection. If these parameters are given, but no paragraph, a callback will be returned that will expect a paragraph. If a paragraph is given, the selector will return immediately.

For example, the s_command selector expects a parameter that can be the name of the command desired. Both of the following uses are valid:

  # create and use a callback:

  my $selector = s_command('head1');
  my @headers  = grep { $selector->($_) } @paragraphs;

  # just check a paragraph right now:

  if ( s_command('head1', $paragraph) ) { ... }

The selectors can be imported individually or as the -all group, and can be renamed with Sub::Exporter features. (Selectors cannot yet be curried by Sub::Exporter.)


  my $callback = s_blank;

  if( s_blank($para) ) { ... }

s_blank tests whether a paragraph is a Generic::Blank element.


  my $callback = s_flat;

  if( s_flat($para) ) { ... }

s_flat tests whether a paragraph does Pod::Elemental::Flat -- in other words, is content-only.


  my $callback = s_node;

  if( s_node($para) ) { ... }

s_node tests whether a paragraph does Pod::Elemental::Node -- in other words, whether it may have children.


  my $callback = s_command;
  my $callback = s_command( $command_name);
  my $callback = s_command(\@command_names);

  if( s_command(undef, \$para) ) { ... }

  if( s_command( $command_name,  \$para) ) { ... }
  if( s_command(\@command_names, \$para) ) { ... }

s_command tests whether a paragraph does Pod::Elemental::Command. If a command name (or a reference to an array of command names) is given, the tested paragraph's command must match one of the given command names.


Ricardo SIGNES <>


This software is copyright (c) 2022 by Ricardo SIGNES.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.