UNIVERSAL::ref - Turns ref() into a multimethod
# True! Wrapper pretends to be Thing. ref( Wrapper->new( Thing->new ) ) eq ref( Thing->new ); package Thing; sub new { bless [], shift } package Wrapper; sub new { my ($class,$proxy) = @_; bless \ $proxy, $class; } sub ref { my $self = shift @_; return $$self; }
This module changes the behavior of the builtin function ref(). If ref() is called on an object that has requested an overloaded ref, the object's ->ref method will be called and its return value used instead.
->ref
To enable this feature for a class, use UNIVERSAL::ref in your class. Here is a sample proxy module.
use UNIVERSAL::ref
package Pirate; # Pirate pretends to be a Privateer use UNIVERSAL::ref; sub new { bless {}, shift } sub ref { return 'Privateer' }
Anywhere you call ref($obj) on a Pirate object, it will allow Pirate to lie and pretend to be something else.
ref($obj)
Pirate
A pragma for ref()-enabling your class. This adds the calling class name to a global list of ref()-enabled classes.
package YourClass; use UNIVERSAL::ref; sub ref { ... }
A pragma for ref()-disabling your class. This removes the calling class name from a global list of ref()-enabled classes.
Currently UNIVERSAL::ref must be installed before any ref() calls that are to be affected.
I think ref() always occurs in an implicit scalar context. There is no accomodation for list context.
UNIVERSAL::ref probably shouldn't allow a module to lie to itself. Or should it?
ambrus for the excellent idea to overload defined() to allow Perl 5 to have Perl 6's "interesting values of undef."
chromatic for pointing out how utterly broken ref() is. This fix covers its biggest hole.
Joshua ben Jore - jjore@cpan.org
The standard Artistic / GPL license most other perl code is typically using.
To install UNIVERSAL::ref, copy and paste the appropriate command in to your terminal.
cpanm
cpanm UNIVERSAL::ref
CPAN shell
perl -MCPAN -e shell install UNIVERSAL::ref
For more information on module installation, please visit the detailed CPAN module installation guide.