n-ary function example

median.raku

subset Even of Int where * %% 2;

sub median {
  my @n = @_;
  given @n.elems {
    when 0    { return () }
    when Even { return @n.sort[@n/2-1, @n/2].sum/2 } # avg of two middle elements
    default   { return @n.sort[(@n+1)/2-1] } # middle element
  }
}

# say median(1, 0);		# (0, 1)[0,1].sum/2 => 0.5
# say median(0, 2, 1);		# (0, 1, 2)[1] => 1
# say median();     		# => ()
# say median(6, 1, 3, 2, 5, 4);	# (1, 2, 3, 4, 5, 6)[2,3].sum/2 => 3.5