Pandoc::Filter::HeaderIdentifiers - Add identifiers to headers

InPandocHeaderIdentifier
       Matches all Unicode lowercase letters, digits 0 to 9, underscore, hyphen, and period. In the unlikely
       event that you want to check whether a given string could have been generated as header identifier, use
       this:

         $id =~ /^\p{InPandocHeaderIdentifier}+$/ and $id =~ /^\p{Letter}/

       This Pandoc::Filter adds identifier attributes (id) to all Headers elements. It uses the same algorithm
       as internally used by pandoc.  The module also exports function "header_identifier" to calculate an
       identifier from a list of elements.

header_identifier($content[,$ids])
       Returns an identifier for a given list of inlines or string ($content). Optionally takes into account and
       updates existing ids, given as hash reference mapping identifier to usage count ($ids).

apply($element[,$ids])
       Add identifiers to all Header elements found at a given element (typically a Document. A hash reference
       of existing identifier counts (or an empty hash to get the new counts) can be passed in addition.

       Pandoc::Filter::HeaderIdentifiers - Add identifiers to headers

       <http://pandoc.org/MANUAL.html#header-identifiers>

perl v5.38.2                                       2024-08-03             Pandoc::Filter::HeaderIdentifiers(3pm)

         my $id = header_identifier( $header->content );       # calculate identifier

         Pandoc::Filter::HeaderIdentifiers->new->apply($doc);  # add all identifiers