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Manual Reference Pages  -  EXPORTER::TIDY (3)

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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.

    use Exporter::Tidy LIST

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:
all If you don’t provide an all tag yourself, Tidy::Exporter will generate one for you. It will contain all exportable symbols.
default 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.

    Exportable symbols

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

    Symbol types

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

    Importing from a module that uses Exporter::Tidy

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.

    Memory usage

 perl -lerequire 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 :)


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


Juerd Waalboer <> <>
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perl v5.20.3 TIDY (3) 2015-01-06

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