package Printable;
use overload '""'=>sub { shift->() };
package main;

sub make_printer{
   my ($fmt)=shift;
   my $args=\@_;
   bless sub { sprintf $fmt,@$args },'Printable';
}

my ($x,$y,$z);
my $formatted=make_printer("%5d %5d   %f\n",$x,$y,$z);
while (++$x<10) {
  $y=$x**2;
  $z=1/$x;
  print $formatted;
}