# usage: special_last_map { block } $sentinel_variable, @list_of_values;
# You should examine the value of the sentinel variable inside your code block.
# It will be True for the last item in the list; False otherwise.

sub special_last_map(&\$@)
{
	my $code = shift;
	my $is_last_sr = shift;

	my $n = $#_;
	map {
		$$is_last_sr = $_ == $n;
		local $_ = $_[$_];
		&$code
	} 0 .. $#_
}


##</code><code>##


my $is_last;
my @list_in_html =
	special_last_map
	{
		my $attr = $is_last ? ' class="last"' : '';
		"<li$attr>$_</li>"
	}
	$is_last,
	@list;


##</code><code>##

sub map_with_index(&@)
{
	my $code = shift;
	my $n = $#_;
	map {
		local $a = $_;
		local $b = $n - $_;
		local $_ = $_[$_];
		&$code
	} 0 .. $#_
}

##</code><code>##

print for map_with_index
{
	my $class = ( $a == 0 ? 'first' : '' ) . ( $b == 0 ?  'last' : '' );
	my $attr = $class ? qq( class="$class") : '';
	"<li$attr>$_</li>\n"
}
qw( alpha beta gamma delta );