It seems to me you've just changed the nature of the problem slightly: before, if you created a new specialnode that inherits from node, you had to modify all of the container objects to know about the new type. Now, if you create a new container type specialmatrix object that inherits from matrix, you have to modify all of the containable object to know about this new type.

One way to solve the problem is to use the isa method from UNIVERSAL. You can say if ($obj->isa('Node')) to see if an object is a Node, or inherits from Node.

In reply to Re: "polymorphism" hack: nuts or wise? by sgifford
in thread "polymorphism" hack: nuts or wise? by rvosa

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