Sub::Install

Section: User Contributed Perl Documentation (3)
Updated: 2021-01-27
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NAME

Sub::Install - install subroutines into packages easily

VERSION

version 0.928

SYNOPSIS

  use Sub::Install;

  Sub::Install::install_sub({
    code => sub { ... },
    into => $package,
    as   => $subname
  });

DESCRIPTION

This module makes it easy to install subroutines into packages without the unsightly mess of "no strict" or typeglobs lying about where just anyone can see them.

FUNCTIONS

install_sub

  Sub::Install::install_sub({
   code => \&subroutine,
   into => "Finance::Shady",
   as   => 'launder',
  });

This routine installs a given code reference into a package as a normal subroutine. The above is equivalent to:

  no strict 'refs';
  *{"Finance::Shady" . '::' . "launder"} = \&subroutine;

If "into" is not given, the sub is installed into the calling package.

If "code" is not a code reference, it is looked for as an existing sub in the package named in the "from" parameter. If "from" is not given, it will look in the calling package.

If "as" is not given, and if "code" is a name, "as" will default to "code". If "as" is not given, but if "code" is a code ref, Sub::Install will try to find the name of the given code ref and use that as "as".

That means that this code:

  Sub::Install::install_sub({
    code => 'twitch',
    from => 'Person::InPain',
    into => 'Person::Teenager',
    as   => 'dance',
  });

is the same as:

  package Person::Teenager;

  Sub::Install::install_sub({
    code => Person::InPain->can('twitch'),
    as   => 'dance',
  });

reinstall_sub

This routine behaves exactly like "install_sub", but does not emit a warning if warnings are on and the destination is already defined.

install_installers

This routine is provided to allow Sub::Install compatibility with Sub::Installer. It installs "install_sub" and "reinstall_sub" methods into the package named by its argument.

 Sub::Install::install_installers('Code::Builder'); # just for us, please
 Code::Builder->install_sub({ name => $code_ref });

 Sub::Install::install_installers('UNIVERSAL'); # feeling lucky, punk?
 Anything::At::All->install_sub({ name => $code_ref });

The installed installers are similar, but not identical, to those provided by Sub::Installer. They accept a single hash as an argument. The key/value pairs are used as the "as" and "code" parameters to the "install_sub" routine detailed above. The package name on which the method is called is used as the "into" parameter.

Unlike Sub::Installer's "install_sub" will not eval strings into code, but will look for named code in the calling package.

EXPORTS

Sub::Install exports "install_sub" and "reinstall_sub" only if they are requested.

exporter

Sub::Install has a never-exported subroutine called "exporter", which is used to implement its "import" routine. It takes a hashref of named arguments, only one of which is currently recognize: "exports". This must be an arrayref of subroutines to offer for export.

This routine is mainly for Sub::Install's own consumption. Instead, consider Sub::Exporter.

EXTRA CREDITS

Several of the tests are adapted from tests that shipped with Damian Conway's Sub-Installer distribution.

AUTHOR

Ricardo SIGNES <rjbs@cpan.org>

COPYRIGHT AND LICENSE

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