NAME
    Package::CopyFrom - Copy (some) contents from another package

VERSION
    This document describes version 0.002 of Package::CopyFrom (from Perl
    distribution Package-CopyFrom), released on 2020-02-16.

SYNOPSIS
     package My::Package;
     use Package::CopyFrom; # exports copy_from()

     BEGIN { copy_from 'Your::Package' }

     # provide your own variables/subroutines
     our $scalar = 'foo';
     sub func1 { ... }
     ...

     1;

DESCRIPTION
    This module provides "copy_from" to fill the contents of the caller's
    (target) package from the specified (source) package, with some options.
    "copy_from" can be used as an alternative to OO inheritance: you copy
    routines from another "base" package then add/modify some other.

FUNCTIONS
  copy_from
    Usage:

     copy_from [ \%opts, ] $source_package

    Load module $source_package if not already loaded (unless the "load"
    option is set to false, in which case no module loading is done), then
    copy the contents of the package into the caller's package. Currently
    only coderefs, scalars, arrays, and hashes are copied.

    Options:

    *   to

        String. Default to "copy_from"'s caller package. Can be used to
        explicitly set the target package.

    *   load

        Boolean, default true. If set to false, no attempt to load module
        named $source_package is made.

    *   dclone

        Boolean, default false. By default, only shallow copying of arrays
        and hashes are done. If this option is true, Storable's "dclone" is
        used.

    *   skip_sub

        Boolean, default false. Whether to exclude all subs.

    *   skip_scalar

        Boolean. Whether to exclude all scalar variables.

    *   skip_array

        Boolean, default false. Whether to exclude all array variables.

    *   skip_hash

        Boolean, default false. Whether to exclude all hash variables.

    *   exclude

        Arrayref. List of names to exclude.

        Examples:

         exclude => ['@EXPORT', '@EXPORT_OK', '%EXPORT_TAGS', '$VERSION'];

HOMEPAGE
    Please visit the project's homepage at
    <https://metacpan.org/release/Package-CopyFrom>.

SOURCE
    Source repository is at
    <https://github.com/perlancar/perl-Package-CopyFrom>.

BUGS
    Please report any bugs or feature requests on the bugtracker website
    <https://rt.cpan.org/Public/Dist/Display.html?Name=Package-CopyFrom>

    When submitting a bug or request, please include a test-file or a patch
    to an existing test-file that illustrates the bug or desired feature.

GOTCHAS
    If your copying module is loaded by user during runtime instead of
    compile-time, then subroutine name from your module will be overwritten
    by the runtime "copy_from" invocation. Illustration:

     # in Source.pm
     package Source;
     sub func1 { ... }
     sub func2 { print "Source's version" }
     1;

     # in YourModule.pm
     package YourModule;
     use Package::CopyFrom;
     copy_from 'Source';
     # modify func2
     sub func2 { "YourModule's version" }
     1;

     # in script1.pl
     use YourModule;
     YourModule::func2(); # prints "YourModule's version", ok.

     # in script2.pl
     require YourModule;
     YourModule::func2(); # prints "Source's version"!

    To ensure that your subroutines do not get copied (overwritten) by the
    source package's that have the same name, perform the copying at
    compile-time:

     # in YourModule.pm
     package YourModule;
     BEGIN { use Package::CopyFrom; copy_from 'Source' }
     # modify func2
     sub func2 { "YourModule's version" }
     1;

SEE ALSO
    Package::Rename can also copy packages.

AUTHOR
    perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2020 by perlancar@cpan.org.

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

