[E-Lang] Summary for Practical Programming
Mark S. Miller
Thu, 01 Feb 2001 15:01:47 -0800
At 02:44 PM Thursday 2/1/01, Bill Frantz wrote:
>Marc - Thanks for trying to summarize things.
>At 02:15 PM 2/1/01 -0700, Marc Stiegler wrote:
>>6. We all agree that POLA is an inherent characteristic in the nature of
>>capability systems, and to the various extents that each individual in this
>>discussion knows the actual behaviors of these implementations, POLA is a
>>part of both E and EROS as actual implementations.
>I am not sure about this one. I think some of the early capability systems
>did not easily support POLA. (Where is my copy of Levy.) Certainly one
>could design a capability system where every call (by convention) passed a
>capability to the home directory. I think a rewording is in order.
I hate to do this to you Alan, but I think you're our live representative of
this family of systems. From previous correspondence on the list, I have
come to think of E-Speak2.2 firmly as a capability system. (Certainly much
more so than SPKI or E-Speak-3.) However, I recall there was something like
an implicit inheritance of vast amounts of authority from a parent to a
child, analogous to Unix's fork() or exec(). I remember it struck the rest
of us as a gross violation of POLA, you didn't disagree, but said it was
necessary to avoid confusing your target audience.
Does any of this ring a bell? Does it sound right?