NAME

       CPAN::Meta::Requirements - a set of version requirements for a CPAN dist

VERSION

       version 2.122

SYNOPSIS

         use CPAN::Meta::Requirements;

         my $build_requires = CPAN::Meta::Requirements->new;

         $build_requires->add_minimum('Library::Foo' => 1.208);

         $build_requires->add_minimum('Library::Foo' => 2.602);

         $build_requires->add_minimum('Module::Bar'  => 'v1.2.3');

         $METAyml->{build_requires} = $build_requires->as_string_hash;

DESCRIPTION

       A CPAN::Meta::Requirements object models a set of version constraints like those specified in the
       META.yml or META.json files in CPAN distributions.  It can be built up by adding more and more
       constraints, and it will reduce them to the simplest representation.

       Logically impossible constraints will be identified immediately by thrown exceptions.

METHODS

   new
         my $req = CPAN::Meta::Requirements->new;

       This returns a new CPAN::Meta::Requirements object.  It takes an optional hash reference argument.  The
       following keys are supported:

       •   <bad_version_hook> -- if provided, when a version cannot be parsed into

           a  version object, this code reference will be called with the invalid version string as an argument.
           It must return a valid version object.

       All other keys are ignored.

   add_minimum
         $req->add_minimum( $module => $version );

       This adds a new minimum version requirement.  If  the  new  requirement  is  redundant  to  the  existing
       specification, this has no effect.

       Minimum requirements are inclusive.  $version is required, along with any greater version number.

       This method returns the requirements object.

   add_maximum
         $req->add_maximum( $module => $version );

       This  adds  a  new  maximum  version  requirement.   If  the new requirement is redundant to the existing
       specification, this has no effect.

       Maximum requirements are inclusive.  No version strictly greater than the given version is allowed.

       This method returns the requirements object.

   add_exclusion
         $req->add_exclusion( $module => $version );

       This adds a new excluded version.  For example, you might use these three method calls:

         $req->add_minimum( $module => '1.00' );
         $req->add_maximum( $module => '1.82' );

         $req->add_exclusion( $module => '1.75' );

       Any version between 1.00 and 1.82 inclusive would be acceptable, except for 1.75.

       This method returns the requirements object.

   exact_version
         $req->exact_version( $module => $version );

       This sets the version required for the given module to exactly the given version.  No other version would
       be considered acceptable.

       This method returns the requirements object.

   add_requirements
         $req->add_requirements( $another_req_object );

       This method adds all the requirements in the given CPAN::Meta::Requirements object  to  the  requirements
       object on which it was called.  If there are any conflicts, an exception is thrown.

       This method returns the requirements object.

   accepts_module
         my $bool = $req->accepts_modules($module => $version);

       Given an module and version, this method returns true if the version specification for the module accepts
       the provided version.  In other words, given:

         Module => '>= 1.00, < 2.00'

       We will accept 1.00 and 1.75 but not 0.50 or 2.00.

       For modules that do not appear in the requirements, this method will return true.

   clear_requirement
         $req->clear_requirement( $module );

       This removes the requirement for a given module from the object.

       This method returns the requirements object.

   requirements_for_module
         $req->requirements_for_module( $module );

       This  returns  a string containing the version requirements for a given module in the format described in
       CPAN::Meta::Spec or undef if the given  module  has  no  requirements.  This  should  only  be  used  for
       informational  purposes  such as error messages and should not be interpreted or used for comparison (see
       "accepts_module" instead.)

   required_modules
       This method returns a list of all the modules for which requirements have been specified.

   clone
         $req->clone;

       This method returns a clone of the invocant.  The clone and the  original  object  can  then  be  changed
       independent of one another.

   is_simple
       This  method  returns  true  if  and only if all requirements are inclusive minimums -- that is, if their
       string expression is just the version number.

   is_finalized
       This method returns true if the requirements have been finalized by having the "finalize"  method  called
       on them.

   finalize
       This  method  marks  the  requirements finalized.  Subsequent attempts to change the requirements will be
       fatal, if they would result in a change.  If they would not alter the requirements, they have no effect.

       If a finalized set of requirements is cloned, the cloned requirements are not also finalized.

   as_string_hash
       This returns a reference to a hash  describing  the  requirements  using  the  strings  in  the  META.yml
       specification.

       For example after the following program:

         my $req = CPAN::Meta::Requirements->new;

         $req->add_minimum('CPAN::Meta::Requirements' => 0.102);

         $req->add_minimum('Library::Foo' => 1.208);

         $req->add_maximum('Library::Foo' => 2.602);

         $req->add_minimum('Module::Bar'  => 'v1.2.3');

         $req->add_exclusion('Module::Bar'  => 'v1.2.8');

         $req->exact_version('Xyzzy'  => '6.01');

         my $hashref = $req->as_string_hash;

       $hashref would contain:

         {
           'CPAN::Meta::Requirements' => '0.102',
           'Library::Foo' => '>= 1.208, <= 2.206',
           'Module::Bar'  => '>= v1.2.3, != v1.2.8',
           'Xyzzy'        => '== 6.01',
         }

   add_string_requirement
         $req->add_string_requirement('Library::Foo' => '>= 1.208, <= 2.206');

       This  method  parses  the passed in string and adds the appropriate requirement for the given module.  It
       understands version ranges as described in the "Version Ranges" in CPAN::Meta::Spec. For example:

       1.3
       >= 1.3
       <= 1.3
       == 1.3
       != 1.3
       > 1.3
       < 1.3
       >= 1.3, != 1.5, <= 2.0
           A version number without an operator is equivalent to specifying a minimum (">=").  Extra  whitespace
           is allowed.

   from_string_hash
         my $req = CPAN::Meta::Requirements->from_string_hash( \%hash );

       This  is an alternate constructor for a CPAN::Meta::Requirements object.  It takes a hash of module names
       and version requirement strings and returns a new CPAN::Meta::Requirements object.

SUPPORT

   Bugs / Feature Requests
       Please    report    any    bugs    or    feature    requests    through    the    issue    tracker     at
       <http://rt.cpan.org/Public/Dist/Display.html?Name=CPAN-Meta-Requirements>.     You   will   be   notified
       automatically of any progress on your issue.

   Source Code
       This is open source software.  The code repository is available for public review and contribution  under
       the terms of the license.

       <https://github.com/dagolden/cpan-meta-requirements>

         git clone https://github.com/dagolden/cpan-meta-requirements.git

AUTHORS

       •   David Golden <dagolden@cpan.org>

       •   Ricardo Signes <rjbs@cpan.org>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2010 by David Golden and Ricardo Signes.

       This  is  free  software;  you  can  redistribute  it and/or modify it under the same terms as the Perl 5
       programming language system itself.

perl v5.18.2                                       2014-01-06                    CPAN::Meta::Requirements(3perl)