Split Capabilities: Making Capabilities Scale

[Karp, Alan]

> -----Original Message-----
> From: Eric Messick [mailto:eric@syzygy.com]
> Sent: Wednesday, July 26, 2000 2:26 PM
> To: 'Ken Kahn'; Norman Hardy; Mark S. Miller; Karp, Alan
> Cc: 'Dan Bornstein'; e-lang@eros-os.org
> Subject: Re: Split Capabilities: Making Capabilities Scale
> 
> 
> I have an observation about some of the discussion so far here.
> 
> The choice of "von Braun" as the holder of various facets may be
> encouraging some anthropomorphism which isn't appropriate.  It's not
> clear to me that everyone is agreeing on who or what is doing the
> "reasoning" in the example.
> 
> To me, reasoning is being performed by the programmer, who has
> knowledge of the contracts of the various objects/facets being
> employed.  I'm considering "von Braun" to be an object, rather than a
> programmer.  That object doesn't have knowledge of anything beyond the
> facets it's been given, and cannot "reason" about that information in
> any way.
> 
> So: "von Braun" doesn't know about the possibility of an increment
> operation, since it doesn't have the increment facet; the person who
> programmed "von Braun" *does* know about the existence of the
> increment operation and has coded "von Braun" appropriately (what ever
> that might mean).

That's what I was hoping that MarkM would say, that the programmer of the
von Braun object knew about behaviors not represented by facets held by the
programmer who delegated them to von Braun.  I took his statement "No
automatic awareness provided." to mean that this was not the case.  Without
such knowledge, the programmer may not be able to code a correct von Braun
object.

> 
> Hopefully I've improved the clarity of the discussion here...
> 
> -eric
> 

_________________________
Alan Karp
Decision Technology Department
Hewlett-Packard Laboratories MS 1U-2
1501 Page Mill Road
Palo Alto, CA 94304
(650) 857-3967, fax (650) 857-6278