> >Currently, the current object context is passed into a sub as the first
> >element of @_, leading to the familiar construct:
>
> > my $self = shift;
>
> >However, this is a big PITA. In particular, if you support lots of
> >different calling forms (like CGI.pm), you have to check whether $_[0]
> >is a ref, etc, etc, etc.
>
> It is? I don't see that this is a pain at all. It seems like
> a beautiful point of homogenization. You don't force the user
> to say $self; they could use $this if they wanted. Heck, they
> don't need it at all.
>
> my(undef, @args) = @_;
>
> Or as in
>
> shift->fn(@_)
>
> This is one of the things that Larry, in borrowing much of Perl's
> OO from Python, carefully preserved from the parent tongue. Don't
> see why you would break it.
My forthcoming proposal will be that invocants still be passed as $_[0]
by default, but that there be a pragma allowing $_[0] to be automagically
shifted somewhere else during dispatch. For example:
sub method { print "I was called through: $_[0]";
print "My args were: @_[1..$#_]"; } #default
use invocant '$ME';
sub method { print "I was called through: $ME";
print "My args were: @_"; }
use invocant '$MYSELF';
sub method { print "I was called through: $MYSELF";
print "My args were: @_"; }
use invocant 'self';
sub method { print "I was called through: ", self;
print "My args were: @_"; }
use invocant 'this';
sub method { print "I was called through: ", this;
print "My args were: @_"; }
use invocant 'the_great_and_powerful_OZ';
sub method { print "I was called through: ", the_great_and_powerful_OZ;
print "My args were: @_"; }
Backwrds compatibility is preserved, everyone's religion is covered, and
the choice is made explicit.
Damian
