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 theuse
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 exportbar
iffoo
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
Pick your favourite OSI approved license :)
http://www.opensource.org/licenses/alphabetical
ACKNOWLEDGEMENTS
Thanks to Aristotle Pagaltzis for suggesting the name Exporter::Tidy.
AUTHOR
Juerd Waalboer <juerd@cpan.org> <http://juerd.nl/>