namespace::clean - Keep imports and functions out of your namespace
0.07
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;
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.
namespace::clean
By unimporting via no you can tell namespace::clean to start collecting functions for the next use namespace::clean; specification.
no
use namespace::clean;
You can use the -except flag to tell namespace::clean that you don't want it to remove a certain function or method. A common use would be a module exporting an import method along with some functions:
-except
import
use ModuleExportingImport; use namespace::clean -except => [qw( import )];
If you just want to -except a single sub, you can pass it directly. For more than one value you have to use an array reference.
When using namespace::clean together with Moose you want to keep the installed meta method. So your classes should look like:
meta
package Foo; use Moose; use namespace::clean -except => 'meta'; ...
Same goes for Moose::Role.
You shouldn't need to call any of these. Just use the package at the appropriate place.
use
Makes a snapshot of the current defined functions and installs a Scope::Guard in the current scope to invoke the cleanups.
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.
This returns a reference to a hash in a passed package containing information about function names included and excluded from removal.
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.
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. namespace::clean will restore and therefor in effect keep all glob slots that aren't CODE.
foo
$SomePackage
CODE
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.
undef
Scope::Guard
Robert 'phaylon' Sedlacek <rs@474.at>, with many thanks to Matt S Trout for the inspiration on the whole idea.
<rs@474.at>
This program is free software; you can redistribute it and/or modify it under the same terms as perl itself.
To install namespace::clean, copy and paste the appropriate command in to your terminal.
cpanm
cpanm namespace::clean
CPAN shell
perl -MCPAN -e shell install namespace::clean
For more information on module installation, please visit the detailed CPAN module installation guide.