my @list_in_html =
  map_by_index [ sub { "<li>$_</li>" },
    last => sub { qq!<li class="last">$_</li>! }, ], @list;

my @list_in_html =
  map_by_index [ sub { "<li>$_</li>" },
    $#list => sub { qq!<li class="last">$_</li>! }, ], @list;