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.\" ========================================================================
.\"
.IX Title "CPAN::Meta::Requirements 3"
.TH CPAN::Meta::Requirements 3 "2015-12-13" "perl v5.16.3" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
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.nh
.SH "NAME"
CPAN::Meta::Requirements \- a set of version requirements for a CPAN dist
.SH "VERSION"
.IX Header "VERSION"
version 2.140
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\&  use CPAN::Meta::Requirements;
\&
\&  my $build_requires = CPAN::Meta::Requirements\->new;
\&
\&  $build_requires\->add_minimum(\*(AqLibrary::Foo\*(Aq => 1.208);
\&
\&  $build_requires\->add_minimum(\*(AqLibrary::Foo\*(Aq => 2.602);
\&
\&  $build_requires\->add_minimum(\*(AqModule::Bar\*(Aq  => \*(Aqv1.2.3\*(Aq);
\&
\&  $METAyml\->{build_requires} = $build_requires\->as_string_hash;
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
A CPAN::Meta::Requirements object models a set of version constraints like
those specified in the \fI\s-1META\s0.yml\fR or \fI\s-1META\s0.json\fR files in \s-1CPAN\s0 distributions,
and as defined by CPAN::Meta::Spec;
It can be built up by adding more and more constraints, and it will reduce them
to the simplest representation.
.PP
Logically impossible constraints will be identified immediately by thrown
exceptions.
.SH "METHODS"
.IX Header "METHODS"
.SS "new"
.IX Subsection "new"
.Vb 1
\&  my $req = CPAN::Meta::Requirements\->new;
.Ve
.PP
This returns a new CPAN::Meta::Requirements object.  It takes an optional
hash reference argument.  Currently, only one key is supported:
.IP "\(bu" 4
\&\f(CW\*(C`bad_version_hook\*(C'\fR \*(-- if provided, when a version cannot be parsed into a version object, this code reference will be called with the invalid version string as first argument, and the module name as second argument.  It must return a valid version object.
.PP
All other keys are ignored.
.SS "add_minimum"
.IX Subsection "add_minimum"
.Vb 1
\&  $req\->add_minimum( $module => $version );
.Ve
.PP
This adds a new minimum version requirement.  If the new requirement is
redundant to the existing specification, this has no effect.
.PP
Minimum requirements are inclusive.  \f(CW$version\fR is required, along with any
greater version number.
.PP
This method returns the requirements object.
.SS "add_maximum"
.IX Subsection "add_maximum"
.Vb 1
\&  $req\->add_maximum( $module => $version );
.Ve
.PP
This adds a new maximum version requirement.  If the new requirement is
redundant to the existing specification, this has no effect.
.PP
Maximum requirements are inclusive.  No version strictly greater than the given
version is allowed.
.PP
This method returns the requirements object.
.SS "add_exclusion"
.IX Subsection "add_exclusion"
.Vb 1
\&  $req\->add_exclusion( $module => $version );
.Ve
.PP
This adds a new excluded version.  For example, you might use these three
method calls:
.PP
.Vb 2
\&  $req\->add_minimum( $module => \*(Aq1.00\*(Aq );
\&  $req\->add_maximum( $module => \*(Aq1.82\*(Aq );
\&
\&  $req\->add_exclusion( $module => \*(Aq1.75\*(Aq );
.Ve
.PP
Any version between 1.00 and 1.82 inclusive would be acceptable, except for
1.75.
.PP
This method returns the requirements object.
.SS "exact_version"
.IX Subsection "exact_version"
.Vb 1
\&  $req\->exact_version( $module => $version );
.Ve
.PP
This sets the version required for the given module to \fIexactly\fR the given
version.  No other version would be considered acceptable.
.PP
This method returns the requirements object.
.SS "add_requirements"
.IX Subsection "add_requirements"
.Vb 1
\&  $req\->add_requirements( $another_req_object );
.Ve
.PP
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.
.PP
This method returns the requirements object.
.SS "accepts_module"
.IX Subsection "accepts_module"
.Vb 1
\&  my $bool = $req\->accepts_module($module => $version);
.Ve
.PP
Given an module and version, this method returns true if the version
specification for the module accepts the provided version.  In other words,
given:
.PP
.Vb 1
\&  Module => \*(Aq>= 1.00, < 2.00\*(Aq
.Ve
.PP
We will accept 1.00 and 1.75 but not 0.50 or 2.00.
.PP
For modules that do not appear in the requirements, this method will return
true.
.SS "clear_requirement"
.IX Subsection "clear_requirement"
.Vb 1
\&  $req\->clear_requirement( $module );
.Ve
.PP
This removes the requirement for a given module from the object.
.PP
This method returns the requirements object.
.SS "requirements_for_module"
.IX Subsection "requirements_for_module"
.Vb 1
\&  $req\->requirements_for_module( $module );
.Ve
.PP
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
\&\*(L"accepts_module\*(R" instead).
.SS "structured_requirements_for_module"
.IX Subsection "structured_requirements_for_module"
.Vb 1
\&  $req\->structured_requirements_for_module( $module );
.Ve
.PP
This returns a data structure containing the version requirements for a given
module or undef if the given module has no requirements.  This should
not be used for version checks (see \*(L"accepts_module\*(R" instead).
.PP
Added in version 2.134.
.SS "required_modules"
.IX Subsection "required_modules"
This method returns a list of all the modules for which requirements have been
specified.
.SS "clone"
.IX Subsection "clone"
.Vb 1
\&  $req\->clone;
.Ve
.PP
This method returns a clone of the invocant.  The clone and the original object
can then be changed independent of one another.
.SS "is_simple"
.IX Subsection "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.
.SS "is_finalized"
.IX Subsection "is_finalized"
This method returns true if the requirements have been finalized by having the
\&\f(CW\*(C`finalize\*(C'\fR method called on them.
.SS "finalize"
.IX Subsection "finalize"
This method marks the requirements finalized.  Subsequent attempts to change
the requirements will be fatal, \fIif\fR they would result in a change.  If they
would not alter the requirements, they have no effect.
.PP
If a finalized set of requirements is cloned, the cloned requirements are not
also finalized.
.SS "as_string_hash"
.IX Subsection "as_string_hash"
This returns a reference to a hash describing the requirements using the
strings in the CPAN::Meta::Spec specification.
.PP
For example after the following program:
.PP
.Vb 1
\&  my $req = CPAN::Meta::Requirements\->new;
\&
\&  $req\->add_minimum(\*(AqCPAN::Meta::Requirements\*(Aq => 0.102);
\&
\&  $req\->add_minimum(\*(AqLibrary::Foo\*(Aq => 1.208);
\&
\&  $req\->add_maximum(\*(AqLibrary::Foo\*(Aq => 2.602);
\&
\&  $req\->add_minimum(\*(AqModule::Bar\*(Aq  => \*(Aqv1.2.3\*(Aq);
\&
\&  $req\->add_exclusion(\*(AqModule::Bar\*(Aq  => \*(Aqv1.2.8\*(Aq);
\&
\&  $req\->exact_version(\*(AqXyzzy\*(Aq  => \*(Aq6.01\*(Aq);
\&
\&  my $hashref = $req\->as_string_hash;
.Ve
.PP
\&\f(CW$hashref\fR would contain:
.PP
.Vb 6
\&  {
\&    \*(AqCPAN::Meta::Requirements\*(Aq => \*(Aq0.102\*(Aq,
\&    \*(AqLibrary::Foo\*(Aq => \*(Aq>= 1.208, <= 2.206\*(Aq,
\&    \*(AqModule::Bar\*(Aq  => \*(Aq>= v1.2.3, != v1.2.8\*(Aq,
\&    \*(AqXyzzy\*(Aq        => \*(Aq== 6.01\*(Aq,
\&  }
.Ve
.SS "add_string_requirement"
.IX Subsection "add_string_requirement"
.Vb 2
\&  $req\->add_string_requirement(\*(AqLibrary::Foo\*(Aq => \*(Aq>= 1.208, <= 2.206\*(Aq);
\&  $req\->add_string_requirement(\*(AqLibrary::Foo\*(Aq => v1.208);
.Ve
.PP
This method parses the passed in string and adds the appropriate requirement
for the given module.  A version can be a Perl \*(L"v\-string\*(R".  It understands
version ranges as described in the \*(L"Version Ranges\*(R" in CPAN::Meta::Spec. For
example:
.IP "1.3" 4
.IX Item "1.3"
.PD 0
.IP ">= 1.3" 4
.IX Item ">= 1.3"
.IP "<= 1.3" 4
.IX Item "<= 1.3"
.IP "== 1.3" 4
.IX Item "== 1.3"
.IP "!= 1.3" 4
.IX Item "!= 1.3"
.IP "> 1.3" 4
.IX Item "> 1.3"
.IP "< 1.3" 4
.IX Item "< 1.3"
.IP ">= 1.3, != 1.5, <= 2.0" 4
.IX Item ">= 1.3, != 1.5, <= 2.0"
.PD
A version number without an operator is equivalent to specifying a minimum
(\f(CW\*(C`>=\*(C'\fR).  Extra whitespace is allowed.
.SS "from_string_hash"
.IX Subsection "from_string_hash"
.Vb 2
\&  my $req = CPAN::Meta::Requirements\->from_string_hash( \e%hash );
\&  my $req = CPAN::Meta::Requirements\->from_string_hash( \e%hash, \e%opts );
.Ve
.PP
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. As with
add_string_requirement, a version can be a Perl \*(L"v\-string\*(R". Optionally,
you can supply a hash-reference of options, exactly as with the \*(L"new\*(R"
method.
.SH "SUPPORT"
.IX Header "SUPPORT"
.SS "Bugs / Feature Requests"
.IX Subsection "Bugs / Feature Requests"
Please report any bugs or feature requests through the issue tracker
at <https://github.com/Perl\-Toolchain\-Gang/CPAN\-Meta\-Requirements/issues>.
You will be notified automatically of any progress on your issue.
.SS "Source Code"
.IX Subsection "Source Code"
This is open source software.  The code repository is available for
public review and contribution under the terms of the license.
.PP
<https://github.com/Perl\-Toolchain\-Gang/CPAN\-Meta\-Requirements>
.PP
.Vb 1
\&  git clone https://github.com/Perl\-Toolchain\-Gang/CPAN\-Meta\-Requirements.git
.Ve
.SH "AUTHORS"
.IX Header "AUTHORS"
.IP "\(bu" 4
David Golden <dagolden@cpan.org>
.IP "\(bu" 4
Ricardo Signes <rjbs@cpan.org>
.SH "CONTRIBUTORS"
.IX Header "CONTRIBUTORS"
.IP "\(bu" 4
Ed J <mohawk2@users.noreply.github.com>
.IP "\(bu" 4
Karen Etheridge <ether@cpan.org>
.IP "\(bu" 4
Leon Timmermans <fawaka@gmail.com>
.IP "\(bu" 4
robario <webmaster@robario.com>
.SH "COPYRIGHT AND LICENSE"
.IX Header "COPYRIGHT AND LICENSE"
This software is copyright (c) 2010 by David Golden and Ricardo Signes.
.PP
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.