Tidy(3pm) User Contributed Perl Documentation Tidy(3pm)

Exporter::Tidy - Another way of exporting symbols

    package MyModule::HTTP;
    use Exporter::Tidy
        default => [ qw(get) ],
        other   => [ qw(post head) ];
    use MyModule::HTTP qw(:all);
    use MyModule::HTTP qw(:default post);
    use MyModule::HTTP qw(post);
    use MyModule::HTTP _prefix => 'http_', qw(get post);
    use MyModule::HTTP qw(get post), _prefix => 'http_', qw(head);
    use MyModule::HTTP
        _prefix => 'foo', qw(get post),
        _prefix => 'bar', qw(get head);
    package MyModule::Foo;
    use Exporter::Tidy
        default => [ qw($foo $bar quux) ],
        _map    => {
            '$foo' => \$my_foo,
            '$bar' => \$my_bar,
            quux => sub { print "Hello, world!\n" }
        };
    package MyModule::Constants;
    use Exporter::Tidy
        default => [ qw(:all) ],
        _map => {
            FOO     => sub () { 1 },
            BAR     => sub () { 2 },
            OK      => sub () { 1 },
            FAILURE => sub () { 0 }
        };

This module serves as an easy, clean alternative to Exporter. Unlike Exporter, it is not subclassed, but it simply exports a custom import() into your namespace.

With Exporter::Tidy, you don't need to use any package global in your module. Even the subs you export can be lexically scoped.

The list supplied to "use Exporter::Tidy" should be a key-value list. Each key serves as a tag, used to group exportable symbols. The values in this key-value list should be array references. There are a few special tags:

If you don't provide an "all" tag yourself, Tidy::Exporter will generate one for you. It will contain all exportable symbols.
The "default" tag will be used if the user supplies no list to the "use" statement.
_map
With _map you should not use an array reference, but a hash reference. Here, you can rewrite symbols to other names or even define one on the spot by using a reference. You can "foo => 'bar'" to export "bar" if "foo" is requested.

Every symbol specified in a tag's array, or used as a key in _map's hash is exportable.

You can export subs, scalars, arrays, hashes and typeglobs. Do not use an ampersand ("&") for subs. All other types must have the proper sigil.

You can use either a symbol name (without the sigil if it is a sub, or with the appropriate sigil if it is not), or a tag name prefixed with a colon. It is possible to import a symbol twice, but a symbol is never exported twice under the same name, so you can use tags that overlap. If you supply any list to the "use" statement, ":default" is no longer used if not specified explicitly.

To avoid name clashes, it is possible to have symbols prefixed. Supply "_prefix" followed by the prefix that you want. Multiple can be used.

    use Some::Module qw(foo bar), _prefix => 'some_', qw(quux);

imports Some::Module::foo as foo, Some::Module::bar as bar, and Some::Module::quux as some_quux. See the SYNOPSIS for more examples.

Exporter::Tidy "versus" Exporter

These numbers are valid for my Linux system with Perl 5.8.0. Your mileage may vary.

Exporting two symbols using no import list (@EXPORT and :default) is approximately 10% faster with Exporter. But if you use any tag explicitly, Exporter::Tidy is more than twice as fast (!) as Exporter.

 perl -le'require X; print((split " ", `cat /proc/$$/stat`)[22])'
 No module       3022848
 Exporter::Tidy  3067904
 Exporter        3084288
 Exporter::Heavy 3174400

Exporter loads Exporter::Heavy automatically when needed. It is needed to support exporter tags, amongst other things. Exporter::Tidy has all functionality built into one module.

Both Exporter(::Heavy) and Exporter::Tidy delay loading Carp until it is needed.

Exporter is subclassed and gets its information from package global variables like @EXPORT, @EXPORT_OK and %EXPORT_TAGS.

Exporter::Tidy exports an "import" method and gets its information from the "use" statement.

Pick your favourite OSI approved license :)

http://www.opensource.org/licenses/alphabetical

Thanks to Aristotle Pagaltzis for suggesting the name Exporter::Tidy.

Juerd Waalboer <juerd@cpan.org> <http://juerd.nl/>

2022-06-13 perl v5.34.0