NAME
namespace::clean - Keep imports and functions out of your namespace
VERSION
0.03
SYNOPSIS
package Foo;
use warnings;
use strict;
use Carp qw(croak); # 'croak' will be removed
sub bar { 23 } # 'bar' will be removed
# remove all previously defined functions
use namespace::clean;
sub baz { bar() } # 'baz' still defined, 'bar' still bound
# begin to collection function names from here again
no namespace::clean;
sub quux { baz() } # 'quux' will be removed
# remove all functions defined after the 'no' unimport
use namespace::clean;
# Will print: 'No', 'No', 'Yes' and 'No'
print +(__PACKAGE__->can('croak') ? 'Yes' : 'No'), "\n";
print +(__PACKAGE__->can('bar') ? 'Yes' : 'No'), "\n";
print +(__PACKAGE__->can('baz') ? 'Yes' : 'No'), "\n";
print +(__PACKAGE__->can('quux') ? 'Yes' : 'No'), "\n";
1;
DESCRIPTION
When you define a function, or import one, into a Perl package, it will
naturally also be available as a method. This does not per se cause
problems, but it can complicate subclassing and, for example, plugin
classes that are included via multiple inheritance by loading them as
base classes.
The "namespace::clean" pragma will remove all previously declared or
imported symbols at the end of the current package's compile cycle.
Functions called in the package itself will still be bound by their
name, but they won't show up as methods on your class or instances.
By unimporting via "no" you can tell "namespace::clean" to start
collecting functions for the next "use namespace::clean;" specification.
METHODS
You shouldn't need to call any of these. Just "use" the package at the
appropriate place.
import
Makes a snapshot of the current defined functions and registers a
Filter::EOF cleanup routine to remove those symbols at the end of the
compile-time.
unimport
This method will be called when you do a
no namespace::clean;
It will start a new section of code that defines functions to clean up.
get_class_store
This returns a reference to a hash in a passed package containing
information about function names included and excluded from removal.
get_functions
Takes a class as argument and returns all currently defined functions in
it as a hash reference with the function name as key and a typeglob
reference to the symbol as value.
IMPLEMENTATION DETAILS
This module works through the effect that a
delete $SomePackage::{foo};
will remove the "foo" symbol from $SomePackage for run time lookups
(e.g., method calls) but will leave the entry alive to be called by
already resolved names in the package itself.
A test file has been added to the perl core to ensure that this
behaviour will be stable in future releases.
Just for completeness sake, if you want to remove the symbol completely,
use "undef" instead.
SEE ALSO
Filter::EOF
AUTHOR AND COPYRIGHT
Robert 'phaylon' Sedlacek "<
[email protected]>", with many thanks to Matt S
Trout for the inspiration on the whole idea.
LICENSE
This program is free software; you can redistribute it and/or modify it
under the same terms as perl itself.
