NAME

Exporter::Tidy - Another way of exporting symbols

SYNOPSIS

    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 }
        };

DESCRIPTION

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.

COMPARISON

Exporter::Tidy "versus" Exporter

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

Speed

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 -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.

Usage

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.

LICENSE

This software may be redistributed under the terms of the GPL, LGPL, modified BSD, or Artistic license, or any of the other OSI approved licenses listed at http://www.opensource.org/licenses/alphabetical. Distribution is allowed under all of these licenses, or any smaller subset of multiple or just one of these licenses.

When using a packaged version, please refer to the package metadata to see under which license terms it was distributed. Alternatively, a distributor may choose to replace the LICENSE section of the documentation and/or include a LICENSE file to reflect the license(s) they chose to redistribute under.

ACKNOWLEDGEMENTS

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

AUTHOR

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