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package Munin::Node::Utils;
# $Id$
use strict;
use warnings;
use Exporter ();
our @ISA = qw/Exporter/;
our @EXPORT_OK = qw/
set_difference
set_intersection
/;
### Set operations #############################################################
sub set_difference
{
my ($A, $B) = @_;
my %set;
@set{@$A} = ();
delete @set{@$B};
return sort keys %set;
}
sub set_intersection
{
my ($A, $B) = @_;
my %set;
@set{@$A} = (1) x @$A;
return sort grep $set{$_}, @$B;
}
1;
__END__
=head1 NAME
Munin::Node::Utils - Various utility functions
=head1 SYNOPSIS
use Munin::Node::Utils qw( ... );
=head1 SUBROUTINES
=over
=item B<set_difference(\@a, \@b)>
Returns the list of elements in arrayref \@a that are not in arrayref \@b.
=item B<set_intersection(\@a, \@b)>
Returns the list of elements common to arrayrefs \@a and \@b.
=cut
# vim: ts=4 : et
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