晋太元中,武陵人捕鱼为业。缘溪行,忘路之远近。忽逢桃花林,夹岸数百步,中无杂树,芳草鲜美,落英缤纷。渔人甚异之,复前行,欲穷其林。   林尽水源,便得一山,山有小口,仿佛若有光。便舍船,从口入。初极狭,才通人。复行数十步,豁然开朗。土地平旷,屋舍俨然,有良田、美池、桑竹之属。阡陌交通,鸡犬相闻。其中往来种作,男女衣着,悉如外人。黄发垂髫,并怡然自乐。   见渔人,乃大惊,问所从来。具答之。便要还家,设酒杀鸡作食。村中闻有此人,咸来问讯。自云先世避秦时乱,率妻子邑人来此绝境,不复出焉,遂与外人间隔。问今是何世,乃不知有汉,无论魏晋。此人一一为具言所闻,皆叹惋。余人各复延至其家,皆出酒食。停数日,辞去。此中人语云:“不足为外人道也。”(间隔 一作:隔绝)   既出,得其船,便扶向路,处处志之。及郡下,诣太守,说如此。太守即遣人随其往,寻向所志,遂迷,不复得路。   南阳刘子骥,高尚士也,闻之,欣然规往。未果,寻病终。后遂无问津者。 sh-3ll

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DIR:/usr/local/share/perl5/Alien/Build/Version/
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Current File : //usr/local/share/perl5/Alien/Build/Version/Basic.pm
package Alien::Build::Version::Basic;

use strict;
use warnings;
use 5.008004;
use Carp ();
use Exporter qw( import );
use overload
  '<=>'    => sub { shift->cmp(@_) },
  'cmp'    => sub { shift->cmp(@_) },
  '""'     => sub { shift->as_string },
  bool     => sub { 1 },
  fallback => 1;

our @EXPORT_OK = qw( version );

# ABSTRACT: Very basic version object for Alien::Build
our $VERSION = '2.80'; # VERSION


sub new
{
  my($class, $value) = @_;
  $value =~ s/\.$//;  # trim trailing dot
  Carp::croak("invalud version: $value")
    unless $value =~ /^[0-9]+(\.[0-9]+)*$/;
  bless \$value, $class;
}


sub version ($)
{
  my($value) = @_;
  __PACKAGE__->new($value);
}


sub as_string
{
  my($self) = @_;
  "@{[ $$self ]}";
}


sub cmp
{
  my @x = split /\./, ${$_[0]};
  my @y = split /\./, ${ref($_[1]) ? $_[1] : version($_[1])};

  while(@x or @y)
  {
    my $x = (shift @x) || 0;
    my $y = (shift @y) || 0;
    return $x <=> $y if $x <=> $y;
  }

  0;
}


1;

__END__

=pod

=encoding UTF-8

=head1 NAME

Alien::Build::Version::Basic - Very basic version object for Alien::Build

=head1 VERSION

version 2.80

=head1 SYNOPSIS

OO interface:

 use Alien::Build::Version::Basic;
 
 my $version = Alien::Build::Version::Basic->new('1.2.3');
 if($version > '1.2.2')  # true
 {
   ...
 }

Function interface:

 use Alien::Build::Version::Basic qw( version );
 
 if(version('1.2.3') > version('1.2.2')) # true
 {
   ...
 }
 
 my @sorted = sort map { version($_) } qw( 2.1 1.2.3 1.2.2 );
 # will come out in the order 1.2.2, 1.2.3, 2.1

=head1 DESCRIPTION

This module provides a very basic class for comparing versions.
This is already a crowded space on CPAN.  Parts of L<Alien::Build>
already use L<Sort::Versions>, which is fine for sorting versions.
Sometimes you need to compare to see if versions match exact I<values>,
and the best candidates (such as L<Sort::Versions> on CPAN compare
C<1.2.3.0> and C<1.2.3> as being different.  This class compares
those two as the same.

This class is also quite limited, in that it only works with version
schemes using a doted version numbers or real numbers with a fixed
number of digits.  Versions with: dashes, letters, hex digits, or
anything else are not supported.

This class overloads both C<E<lt>=E<gt>> and C<cmp> to compare the version in
the way that you would expect for version numbers.  This way you can
compare versions like numbers, or sort them using sort.

 if(version($v1) > version($v2))
 {
   ...
 }
 
 my @sorted = sort map { version($_) } @unsorted;

it also overloads C<""> to stringify as whatever string value you
passed to the constructor.

=head1 CONSTRUCTOR

=head2 new

 my $version = Alien::Build::Version::Basic->new($value);

This is the long form of the constructor, if you don't want to import
anything into your namespace.

=head2 version

 my $version = version($value);

This is the short form of the constructor, if you are sane.  It is
NOT exported by default so you will have to explicitly import it.

=head1 METHODS

=head2 as_string

 my $string = $version->as_string;
 my $string = "$version";

Returns the string representation of the version object.

=head2 cmp

 my $bool = $version->cmp($other);
 my $bool = $version <=> $other;
 my $bool = $version cmp $other;

Returns C<-1>, C<0> or C<1> just like the regular C<E<lt>=E<gt>> and C<cmp>
operators.  Although C<$version> must be a version object, C<$other> may
be either a version object, or a string that could be used to create a
valid version object.

=head1 SEE ALSO

=over 4

=item L<Sort::Versions>

Good, especially if you have to support rpm style versions (like C<1.2.3-2-b>)
or don't care if trailing zeros (C<1.2.3> vs C<1.2.3.0>) are treated as
different values.

=item L<version>

Problematic for historical reasons.

=back

=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