use warnings;
use strict;

print html_abstract(<<'END_HTML', 200), "\n";
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed
tristique purus urna, a lacinia nulla euismod et. Pellentesque tempus
et justo faucibus. <i>Fusce scelerisque, <b>magna</b> <a
href="http://www.example.com">efficitur congue, leo nibh</a>
volutpat nibh, ac mattis dolor ipsum sit amet quam.</i> Suspendisse
eleifend id ligula quis placerat. Pellentesque fermentum eu magna sed
mollis. Quisque placerat efficitur blandit. Vestibulum non.</p>
END_HTML

use Mojo::DOM;
sub html_abstract {
	my ($html, $remain) = @_;
	my $walk; $walk = sub {
		my ($in, $out) = @_;
		for my $n ( @{ $in->child_nodes } ) {
			last unless $remain;
			if ( $n->type eq 'cdata' || $n->type eq 'text' ) {
				my $txt = $n->content;
				if ( length $txt < $remain ) {
					$out->append_content($txt);
					$remain -= length $txt;
				}
				else {
					$txt =~ /^(.{0,$remain}\b)/s;
					$out->append_content("$1...");
					$remain = 0;
				}
			}
			elsif ( $n->type eq 'tag' ) {
				my $t = $out->new_tag( $n->tag, %{ $n->attr } )
					# new_tag gives us a "root", but we want the tag
					->child_nodes->first;
				$walk->($n, $t);
				$out->append_content($t);
			} # ignore other node types for now
		}
		return $out;
	};
	return $walk->(Mojo::DOM->new($html), Mojo::DOM->new)->to_string;
}

__END__

<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed
tristique purus urna, a lacinia nulla euismod et. Pellentesque tempus
et justo faucibus. <i>Fusce scelerisque, <b>magna</b> <a href="http://www.example.com">efficitur congue, leo ...</a></i></p>