Debian::Dependency - dependency relationship between Debian packages

                                    # simple dependency
   my $d = Debian::Dependency->new( 'perl' );
                                    # also parses a single argument
   my $d = Debian::Dependency->new('perl (>= 5.10)');
                                    # dependency with a version
   my $d = Debian::Dependency->new( 'perl', '5.10' );
                                    # dependency with version and relation
   my $d = Debian::Dependency->new( 'perl', '>=', '5.10' );

   print $d->pkg;  # 'perl'
   print $d->ver;  # '5.10'

                                    # for people who like to type much
   my $d = Debian::Dependency->new( { pkg => 'perl', ver => '5.10' } );

   # stringification
   print "$d"      # 'perl (>= 5.10)'

   # 'adding'
   $deps = $dep1 + $dep2;
   $deps = $dep1 + 'foo (>= 1.23)'

new()

Construnct a new instance.

new( { pkg => 'package', rel => '>=', ver => '1.9' } )

If a hash reference is passed as an argument, its contents are used to initialize the object.

new( [ { pkg => 'foo' }, 'bar (<= 3)' ] );

In an array reference is passed as an argument, its elements are used for constructing a dependency with alternatives.

new('foo (= 42)')

new('foo (= 42) | bar')

If a single argument is given, the construction is passed to the parse constructor.

new( 'foo', '1.4' )

Two arguments are interpreted as package name and version. The relation is assumed to be '>='.

new( 'foo', '=', '42' )

Three arguments are interpreted as package name, relation and version.

set

Overrides the set method from Class::Accessor. Used to convert zero versions (for example 0 or 0.000) to void versions.

parse()

Takes a single string argument and parses it.

Examples:

perl

perl (>= 5.8)

libversion-perl (<< 3.4)

pkg

Contains the name of the package that is depended upon

rel

Contains the relation of the dependency. May be any of '<<', '<=', '=', '>=' or '>>'. Default is '>='.

ver

Contains the version of the package the dependency is about. The value is an instance of Dpkg::Version class. If you set it to a scalar value, that is given to Dpkg::Version->new().

rel and ver are either both present or both missing.

Examples

    print $dep->pkg;
    $dep->ver('3.4');

satisfies($dep)

Returns true if $dep states a dependency that is already covered by this instance. In other words, if this method returns true, any package satisfying the dependency of this instance will also satisfy $dep ($dep is redundant in dependency lists where this instance is already present).

$dep can be either an instance of the Debian::Dependency class, or a plain string.

    my $dep  = Debian::Dependency->new('foo (>= 2)');
    print $dep->satisfies('foo') ? 'yes' : 'no';             # no
    print $dep->satisfies('bar') ? 'yes' : 'no';             # no
    print $dep->satisfies('foo (>= 2.1)') ? 'yes' : 'no';    # yes

Debian::Dependencies

Damyan Ivanov <dmn@debian.org>

Copyright (C) 2008,2009,2010 Damyan Ivanov <dmn@debian.org>

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation.

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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.