NAME
    Module::CPANfile - Parse cpanfile

SYNOPSIS
      use Module::CPANfile;

      my $file = Module::CPANfile->load("cpanfile");
      my $prereqs = $file->prereqs; # CPAN::Meta::Prereqs object

      my @features = $file->features; # CPAN::Meta::Feature objects
      my $merged_prereqs = $file->prereqs_with(@identifiers); # CPAN::Meta::Prereqs

      $file->merge_meta('MYMETA.json');

DESCRIPTION
    Module::CPANfile is a tool to handle cpanfile format to load application
    specific dependencies, not just for CPAN distributions.

METHODS
    load
          $file = Module::CPANfile->load;
          $file = Module::CPANfile->load('cpanfile');

        Load and parse a cpanfile. By default it tries to load "cpanfile" in
        the current directory, unless you pass the path to its argument.

    from_prereqs
          $file = Module::CPANfile->from_prereqs({
            runtime => { requires => { DBI => '1.000' } },
          });

        Creates a new Module::CPANfile object from prereqs hash you can get
        via CPAN::Meta's "prereqs", or CPAN::Meta::Prereqs'
        "as_string_hash".

          # read MYMETA, then feed the prereqs to create Module::CPANfile
          my $meta = CPAN::Meta->load_file('MYMETA.json');
          my $file = Module::CPANfile->from_prereqs($meta->prereqs);

          # load cpanfile, then recreate it with round-trip
          my $file = Module::CPANfile->load('cpanfile');
          $file = Module::CPANfile->from_prereqs($file->prereq_specs);
                                            # or $file->prereqs->as_string_hash

    prereqs
        Returns CPAN::Meta::Prereqs object out of the parsed cpanfile.

    prereq_specs
        Returns a hash reference that should be passed to
        "CPAN::Meta::Prereqs->new".

    features
        Returns a list of features available in the cpanfile as
        CPAN::Meta::Feature.

    prereqs_with(@identifiers)
        Retuens CPAN::Meta::Prereqs object, with merged prereqs for features
        identified with the @identifiers.

    to_string($include_empty)
          $file->to_string;
          $file->to_string(1);

        Returns a canonical string (code) representation for cpanfile.
        Useful if you want to convert CPAN::Meta::Prereqs to a new cpanfile.

          # read MYMETA's prereqs and print cpanfile representation of it
          my $meta = CPAN::Meta->load_file('MYMETA.json');
          my $file = Module::CPANfile->from_prereqs($meta->prereqs);
          print $file->to_sring;

        By default, it omits the phase where there're no modules registered.
        If you pass the argument of a true value, it will print them as
        well.

    save
          $file->save('cpanfile');

        Saves the currently loaded prereqs as a new "cpanfile" by calling
        "to_string". Beware this method will overwrite the existing cpanfile
        without any warning or backup. Taking a backup or giving warnings to
        users is a caller's responsibility.

          # Read MYMETA.json and creates a new cpanfile
          my $meta = CPAN::Meta->load_file('MYMETA.json');
          my $file = Module::CPANfile->from_prereqs($meta->prereqs);
          $file->save('cpanfile');

    merge_meta
          $file->merge_meta('META.yml');
          $file->merge_meta('MYMETA.json', '2.0');

        Merge the effective prereqs with Meta specification loaded from the
        given META file, using CPAN::Meta. You can specify the META spec
        version in the second argument, which defaults to 1.4 in case the
        given file is YAML, and 2 if it is JSON.

AUTHOR
    Tatsuhiko Miyagawa

SEE ALSO
    cpanfile, CPAN::Meta, CPAN::Meta::Spec

