NAME

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

SYNOPSIS

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

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

DESCRIPTION

       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.

FUNCTIONS

   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).

METHODS

   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.

CHARACTER PROPERTIES

   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}/

SEE ALSO

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