package Alien::Util;
use strict;
use warnings;
use Exporter qw( import );
# ABSTRACT: Alien Utilities used at build and runtime
our $VERSION = '2.80'; # VERSION
our @EXPORT_OK = qw( version_cmp );
# Sort::Versions isn't quite the same algorithm because it differs in
# behaviour with leading zeroes.
# See also https://dev.gentoo.org/~mgorny/pkg-config-spec.html#version-comparison
sub version_cmp {
my @x = (shift =~ m/([0-9]+|[a-z]+)/ig);
my @y = (shift =~ m/([0-9]+|[a-z]+)/ig);
while(@x and @y) {
my $x = shift @x; my $x_isnum = $x =~ m/[0-9]/;
my $y = shift @y; my $y_isnum = $y =~ m/[0-9]/;
if($x_isnum and $y_isnum) {
# Numerical comparison
return $x <=> $y if $x != $y;
}
elsif(!$x_isnum && !$y_isnum) {
# Alphabetic comparison
return $x cmp $y if $x ne $y;
}
else {
# Of differing types, the numeric one is newer
return $x_isnum - $y_isnum;
}
}
# Equal so far; the longer is newer
return @x <=> @y;
}
1;
__END__
=pod
=encoding UTF-8
=head1 NAME
Alien::Util - Alien Utilities used at build and runtime
=head1 VERSION
version 2.80
=head1 SYNOPSIS
use Alien::Util qw( version_cmp );
=head1 DESCRIPTION
This module contains some functions used by both the L<Alien::Build> build-time and <Alien::Base>
run-time for Alien.
=head2 version_cmp
$cmp = version_cmp($x, $y)
Comparison method used by L<Alien::Base/atleast_version>, L<Alien::Base/exact_version> and
L<Alien::Base/max_version>. May be useful to implement custom comparisons, or for
subclasses to overload to get different version comparison semantics than the
default rules, for packages that have some other rules than the F<pkg-config>
behaviour.
Should return a number less than, equal to, or greater than zero; similar in
behaviour to the C<< <=> >> and C<cmp> operators.
=head1 SEE ALSO
L<Alien::Base>, L<alienfile>, L<Alien::Build>
=head1 AUTHOR
Author: Graham Ollis E<lt>plicease@cpan.orgE<gt>
Contributors:
Diab Jerius (DJERIUS)
Roy Storey (KIWIROY)
Ilya Pavlov
David Mertens (run4flat)
Mark Nunberg (mordy, mnunberg)
Christian Walde (Mithaldu)
Brian Wightman (MidLifeXis)
Zaki Mughal (zmughal)
mohawk (mohawk2, ETJ)
Vikas N Kumar (vikasnkumar)
Flavio Poletti (polettix)
Salvador Fandiño (salva)
Gianni Ceccarelli (dakkar)
Pavel Shaydo (zwon, trinitum)
Kang-min Liu (劉康民, gugod)
Nicholas Shipp (nshp)
Juan Julián Merelo Guervós (JJ)
Joel Berger (JBERGER)
Petr Písař (ppisar)
Lance Wicks (LANCEW)
Ahmad Fatoum (a3f, ATHREEF)
José Joaquín Atria (JJATRIA)
Duke Leto (LETO)
Shoichi Kaji (SKAJI)
Shawn Laffan (SLAFFAN)
Paul Evans (leonerd, PEVANS)
Håkon Hægland (hakonhagland, HAKONH)
nick nauwelaerts (INPHOBIA)
Florian Weimer
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2011-2022 by Graham Ollis.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut
