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Re^3: Inside-out objects inheriting from hash-based classes

by xdg (Monsignor)
on Dec 07, 2005 at 21:52 UTC ( #515056=note: print w/replies, xml ) Need Help??


in reply to Re^2: Inside-out objects inheriting from hash-based classes
in thread Inside-out objects inheriting from hash-based classes

But what happens if you need/want to make explicit calls to a super class?

print( $object->Borg::comment(), "\n" );

Updated/expanded for clarity

Assume that you have a method of the same name in Borg as you do in Foo:

package Borg; sub comment { return $_[0]->{default_threat}; }

If I want to explicitly call the Borg version of that method, I'd call it as $obj->Borg::comment(). However, that's equivalent to this:

Borg::comment( $obj );

Therefore, if Borg::comment is expecting an object of type Borg and intends to muck with its internal structure directly, this will fail since the real Borg object is hidden in a closure in Foo and keyed to $obj and $obj is just the blessed reference for the inside-out object.

Or have I missed something?

-xdg

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Re^4: Inside-out objects inheriting from hash-based classes
by jdhedden (Deacon) on Dec 08, 2005 at 05:27 UTC
    In the case you describe, Borg::comment is overridden by Foo::comment, and, as a result of the architecture, is not directly callable using $obj->Borg::comment.

    If it was intended by Foo's author that Borg::comment should be overridden, then no one should be writing code that uses Foo and also tries to by-pass Foo's version of the comment method.

    If the overriding was accidently, then either Foo's author can rename Foo::comment, or can provide a wrapper method so that the functionality of Borg::comment is made available under a different name.

    This is an interesting technical point, but I would imagine that a situation like this would rarely occur in practice. Nonetheless, I'll add information about this to the POD. Thanks.

    Update: Actually, this applies to more than just overridden methods. You can't use any fully-qualified method calls to inherited foreign classes. But then again, you shouldn't need to.


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