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# Copyright Bill Allombert <ballombe@debian.org> 2001.
# Modifications copyright 2002 Julian Gilbey <jdg@debian.org>
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
package Devscripts::Set;
use strict;
BEGIN {
use Exporter ();
use vars qw(@EXPORT @ISA %EXPORT_TAGS);
@EXPORT = qw(SetMinus SetInter SetUnion);
@ISA = qw(Exporter);
%EXPORT_TAGS = ();
}
# Several routines to work with arrays whose elements are unique
# (here called sets)
=head1 NAME
Devscripts::Set - Functions for handling sets.
=head1 SYNOPSIS
use Devscripts::Set;
@set=ListToSet(@list);
@setdiff=SetMinus(\@set1,\@set2);
@setinter=SetInter(\@set1,\@set2);
@setunion=SetUnion(\@set1,\@set2);
=head1 DESCRIPTION
ListToSet: Make a set (array with duplicates removed) from a list of
items given by an array.
SetMinus, SetInter, SetUnion: Compute the set theoretic difference,
intersection, union of two sets given as arrays.
=cut
# Transforms a list to a set, removing duplicates
# input: list
# output: set
sub ListToSet (@) {
my %items;
grep $items{$_}++, @_;
return keys %items;
}
# Compute the set-theoretic difference of two sets.
# input: ref to Set 1, ref to Set 2
# output: set
sub SetMinus ($$) {
my ($set1, $set2) = @_;
my %items;
grep $items{$_}++, @$set1;
grep $items{$_}--, @$set2;
return grep $items{$_} > 0, keys %items;
}
# Compute the set-theoretic intersection of two sets.
# input: ref to Set 1, ref to Set 2
# output: set
sub SetInter ($$) {
my ($set1, $set2) = @_;
my %items;
grep $items{$_}++, @$set1;
grep $items{$_}++, @$set2;
return grep $items{$_} == 2, keys %items;
}
#Compute the set-theoretic union of two sets.
#input: ref to Set 1, ref to Set 2
#output: set
sub SetUnion ($$) {
my ($set1, $set2) = @_;
my %items;
grep $items{$_}++, @$set1;
grep $items{$_}++, @$set2;
return grep $items{$_} > 0, keys %items;
}
1;
=head1 AUTHOR
Bill Allombert <ballombe@debian.org>
=head1 COPYING
Copyright 2001 Bill Allombert <ballombe@debian.org>
Modifications Copyright 2002 Julian Gilbey <jdg@debian.org>
dpkg-depcheck is free software, covered by the GNU General Public License, and
you are welcome to change it and/or distribute copies of it under
certain conditions. There is absolutely no warranty for dpkg-depcheck.
=cut
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