Split Capabilities: Making Capabilities Scale

[Karp, Alan]

> -----Original Message-----
> From: Jonathan S. Shapiro [mailto:shap@eros-os.org]
> Sent: Sunday, July 30, 2000 4:54 AM
> To: Karp, Alan; 'Ralph Hartley'
> Cc: e-lang@eros-os.org
> Subject: Re: Split Capabilities: Making Capabilities Scale
> 
> 
> > The fact that a facet purposely hides part of the object's state
> transition
> > diagram from me is the reason I don't equate facet with 
> object.  I don't
> > mind coding within the restrictions imposed by the facet; I 
> just often
> need
> > more information about the behavior of the object.  Even in the real
> world,
> > programmers should be given access to the behavior of the 
> object behind
> the
> > facet.
> 
> It seems to me that we may once again be confused about "I" 
> and "me" in this
> context. The facet is something seen by the program, not 
> something seen by
> the programmer.

"I" is a person.  (I hope my 5th grade English teacher isn't lurking.)

>
> The *programmer* may or may see the entire behavior as you 
> (and mostly, I)
> espouse. This is a policy question to be determined by the 
> developer of the
> component. The presence or absence of facets in the runtime 
> model doesn't
> change this issue one iota.

Exactly.  The programmer reasons about the object; the program works within
the constraints of its facets.

> 
> The *program* sees only the behavior that it's programmer 
> intended it should
> see. It is not the *program* that requires total knowledge, it is the
> *programmer*.

What I've been trying to say, apparently incoherently.

> 
> I truly believe that you are tilting from astride a dead horse. :-)
> 

The only kind I feel comfortable riding.

> 
> shap
> 

_________________________
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