use strict;
use warnings;

use HTML::Template::Compiled;

my $htc = HTML::Template::Compiled->new(
tagstyle => [qw(+asp -comment -php -tt)],
scalarref => \<<'EOT');
    <%= foo%>
    <%= _foo%>
    <%= __foo%>
    <%= ___foo%>
    <%= ____foo%>
EOT
$htc->param(
    foo     => 'bar',
    _foo    => '_bar',
    __foo   => '__bar',
    ___foo  => '___bar',
    ____foo => '____bar',
);
print $htc->output();

__END__

    bar
    bar
    _bar
    __bar
    ___bar