Re: RFC 163 (v2) Objects: Autoaccessors for object data structures

On Mon, 18 Sep 2000 13:26:45 -0700, Glenn Linderman wrote:

>> Read RFC 241 for a brief overview of pseudo-hash problems.
>
>I've already read RFC 241.  Re-reading in this context results in the following
>comments/quests for information.  The remaining quotes here come from RFC 241...
>
>>         Doesn't play well with multiple inheritance
>>
>I can sure believe this.  There'd be indexes from multiple base classes.  I
>don't know how Perl does multiple inheritance anyway, so I can't comment
>effectively on whether this is or would be a problem.  If Perl does multiple
>inheritance, I haven't stumbled across the documentation for it, but neither
>have I looked.  I don't use multiple inheritance.

If the objects are based upon hashes, then it can be done, provided that
all field names are different for both classes. That is a pretty
unreasonable requirement, because it violates the "information hiding"
principle behind OO: these are details you shoudl'nt need to know.

What happens if one class is based upon a hash, and the other on
pseudo-hash, or an array? Duh...

I have a pretty primitive idea in my head: suppose a Taxi object has
multiple inheritance, it inherits from both a Car and a Driver... So a
Taxi is both a Car and a Driver. But shouldn't you also make this that a
Taxi is a Car that also *contains* a Driver, instead of *being* one?

You can even take this further: that a Taxi is an object that contains
both a Car and a Driver. Poof, out the door go the conflicts...

In order to make this work behind the scenes in OO Perl, multiple
inheritance should automatically call SUPER classes with the *contained*
object of that superclass, not with the object itself. If there's both a
Driver and a Car in a Taxi, Car methods have no need to be messing with
the Driver's properties, anyway...

In my childish enthousiasm, I have the feeling that I've just hit a
jackpot...

-- 
	Bart.