#! /usr/bin/perl

package Sieve;
use strict;
use warnings;

sub new { bless [], shift };

sub add_predicate {
	my $self = shift;
	push @$self, shift;
}

sub ok {
	my ($self, $item) = @_;
	$_->($item) || return(0) foreach @$self;
	return(1);
};

sub sieve {
	my $self = shift;
	grep {$self->ok($_)} @_;
};

##</code><code>##

my $o = Sieve->new;
$o->add_predicate( sub { $_[0] > 5 } );
$o->add_predicate( sub { $_[0] % 2 } );

my @original = (1..15);
my @sieved = $o->sieve( @original );
print "original: @original\n";
print "odd numbers > 5 are: @sieved\n";

__END__
producing

original: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
odd numbers > 5 are: 7 9 11 13 15