=head1 NAME

cpanfile - A format for describing CPAN dependencies for Perl applications

=head1 SYNOPSIS

  requires 'Plack', '1.0'; # 1.0 or newer
  requires 'JSON', '>= 2.00, < 2.80';

  recommends 'JSON::XS', '2.0';
  conflicts 'JSON', '< 1.0';

  on 'test' => sub {
    requires 'Test::More', '>= 0.96, < 2.0';
    recommends 'Test::TCP', '1.12';
  };

  on 'develop' => sub {
    recommends 'Devel::NYTProf';
  };

  feature 'sqlite', 'SQLite support' => sub {
    recommends 'DBD::SQLite';
  };

=head1 VERSION

This document describes cpanfile format version 1.0.

=head1 DESCRIPTION  

C<cpanfile> describes CPAN dependencies required to execute associated
Perl code.

=head1 SYNTAX

=over 4

=item requires, recommends, suggests, conflicts

  requires $module, $version_requirement;

Describes the requirement for a module. See L<CPAN::Meta::Spec> for
the meanings of each requirement type.

When version requirement is omitted, it is assumed that C<0> is
passed, meaning any version of the module would satisfy the
requirement.

Version requirement can either be a version number or a string that
satisfies L<CPAN::Meta::Spec/Version Ranges>, such as C<< >= 1.0, !=
1.1 >>.

Note that, per L<CPAN::Meta::Spec>, when a plain version number is
given, it means the version I<or newer> is required. If you want a
specific version for a module, use the specific range syntax, i.e.
C< == 2.1 >.

=item on

  on $phase => sub { ... };

Describe requirements for a specific phase. Available phases are
C<configure>, C<build>, C<test>, C<runtime> and C<develop>.

=item feature

  feature $identifier, $description => sub { ... };

Group requirements with features. Description can be omitted, when it
is assumed to be the same as identifier. See
L<CPAN::Meta::Spec/optional_features> for more details.

=item configure_requires, build_requires, test_requires, author_requires

  configure_requires $module, $version;
  # on 'configure' => sub { requires $module, $version }

  build_requires $module, $version;
  # on 'build' => sub { requires $module, $version };

  test_requires $module, $version;
  # on 'test' => sub { requires $module, $version };

  author_requires $module, $version;
  # on 'develop' => sub { requires $module, $version };

Shortcut for C<requires> in specific phase. This is mainly provided
for compatibilities with L<Module::Install> DSL.

=back

=head1 USAGE

C<cpanfile> is a format to describe dependencies. How to use this file
is dependent on the tools reading/writing it.

Usually, you're expected to place the C<cpanfile> in the root of the
directory containing the associated code.

Tools supporting C<cpanfile> format (e.g. L<cpanm> and L<carton>) will
automatically detect the file and install dependencies for the code to
run.

There are also tools to support converting cpanfile to CPAN toolchain
compatible formats, such as L<Module::CPANfile>,
L<Dist::Zilla::Plugin::Prereqs::FromCPANfile>,
L<Module::Install::CPANfile>, so that C<cpanfile> can be used to
describe dependencies for a CPAN distribution as well.

The L<cpanfile-dump> tool can be used to dump dependencies.

=head1 AUTHOR

Tatsuhiko Miyagawa

=head1 ACKNOWLEDGEMENTS

The format (DSL syntax) is inspired by L<Module::Install> and
L<Module::Build::Functions>.

C<cpanfile> specification (this document) is based on Ruby's
L<Gemfile|http://bundler.io/v1.3/man/gemfile.5.html> specification.

=head1 SEE ALSO

L<CPAN::Meta::Spec> L<Module::Install> L<Carton>

=cut