Challenge my assumptions!

btanksley@hifn.com btanksley@hifn.com
Sat, 3 Jul 1999 12:27:00 -0700


> From:	Jim Little [SMTP:jiml@inconnect.com]
> Subject:	Challenge my assumptions!
> 
> Tunesters,
> 
> I'm in the middle of a big research push for Prism.  A lot of groundwork
> is being laid for critical issues such as language interoperability. 
> Before I get too far, I'd like you to challenge my fundamental Prism
> assumptions.  It will soon be too late to change them easily.
> 
	Okay.  I'd also like to question what you're trying to achieve.  Is
it something which CORBA already does?

> Here they are:
> 1) The basic Prism data types (_Bit, _Stream, _Map) are SUFFICIENT to
> represent any concept, particularly programs.
> 
	No.  I originally believed they were, but some careful examination
has convinced me that they can't model at least certain types of device.  A
packet stream models TCP/IP well, but it fails to model UDP/IP, because UDP
doesn't enforce ordering or preservation.

	If I were helping to design the device system for an OS, I would go
on to discuss the orthogonal ways in which devices may differ.  However, I
don't really know what you're doing, so I can't.

> 2) The basic Prism data types lend themselves to INTUITIVE metamodels
> for representing specific types of concepts, especially programs.  I.e.,
> it's EASY to create Prism metamodels (or, at least, they introduce
> minimal added difficulty).
> 
	No, because programs = data + algorithms.  Prism only models data.

> -Jim
> 
	-Billy