in reply to Re: perspective and object-disorientation
in thread perspective and object-disorientation
Also, from a code re-entrancy requirement, since changes to @ISA are global, it would be very difficult for two sections of code that had different 'perspectives' to access the same set of objects at the same time.
While I don't think changing @ISA willy-nilly is a good idea, changes are global only if you choose to make them that way.
@ISA can be changed locally using... well... local :-) It can be a useful idiom when testing to make one object temporarily appear as another.