#!/usr/bin/perl

  use strict;

  my $as_float_e = Format->new('%8.4e');
  my $as_float   = Format->new('%8.4f');
  my $as_integer = Format->new('%d');
  my $as_string  = Format->new('%20.20s');

  my $var = 1234.5678;

  print $as_float_e ->format($var), "\n";
  print $as_float   ->format($var), "\n";
  print $as_integer ->format($var), "\n";
  print $as_string  ->format($var), "\n";

#-----------------------------------------------------------
  package Format;

#-----------------------------------------------------------
sub new {

  my ($pack, $spec) = @_;

  my $r = {};

  $r->{real} = Format::Real->new();
  $r->{spec} = $spec;

  bless $r, $pack;
}

#-----------------------------------------------------------
sub AUTOLOAD {

  my $r = shift;

  my $func = (split('::', $Format::AUTOLOAD))[-1];

  if (Format::Real->can($func)) {
    $r->{real}->$func($r->{spec}, @_);
  }
}

#-----------------------------------------------------------
  package Format::Real;

#-----------------------------------------------------------
sub new {

  my ($pack) = @_;
  bless {}, $pack;

}

#-----------------------------------------------------------
sub format {

  my $r = shift;
  my ($spec, $num) = @_;

  sprintf $spec, $num;
}