[cap-talk] Concening entry "ambient authority" in Wikipedia

[Sandro Magi]

Toby Murray wrote:
>> Is there a real world ocap system which allows to (at least at startup) deny
>> or exchange the integer number "5"?
>>
> 
> Marcus makes a good point. Most if not all actual ocap systems
> implicitly provide certain capabilities to all objects. However, they
> are supposed to only provide (what I will here call) "ambient"
> capabilities that confer no "real" authority (for some definition of
> "real"). 
> 
> One characterisation of "real" is "If you didn't already have it, you
> couldn't built it yourself." I can't think of a better one but one
> probably exists.

I think the key focus is on the scope of side-effects. By default, no
references are provided to a new object S where the scope of
side-effects extend beyond S itself (essentially, a null set). This is
required for any confinement argument. Values like "5" have no
side-effect. Reference cells have side-effects, but are local only to S
until they are shared.

Sandro