#!/usr/bin/perl use warnings; use strict; my $html = <<'EOHTML';

The relationship can be expressed by the following equation:

y <= (7x³ + 3x²)/((x - 3)(x - 5)

Of course x != 3 & x != 5 -- That goes without saying. EOHTML use HTML::TreeBuilder; my $tree = HTML::TreeBuilder->new_from_content($html); # Look for double-dashes in the text, # and change them to —es. $tree->look_down(sub { my $element = shift; my @content = $element->content_list(); @content = map { if(ref) { $_ # Skip non-text children } else { # Break up the text child into pieces on the --'s my @texts = split /(--)/, $_; # Replaces those --'s with a ~literal # pseudo-element containing an — @texts = map { $_ eq '--' ? HTML::Element->new('~literal', text => '—') : $_ } @texts; @texts; } } @content; # Replace the old content with the modified content $element->splice_content(0, scalar $element->content_list, @content); return 0; }); print $tree->as_HTML;