What about this?

Fare Rideau rideau@ens.fr
Tue, 10 Feb 1998 01:18:46 +0100 (CET)


>: dem, in answer to Maneesh

I fully agree with David's message, but would like to add a few remarks,
to avoid possible confusion (all the more as my very short reference to it
in my answer to Maneesh might have incorrectly suggested
that I took David's message lightly).

> You are still thinking like we are system designers.
> We are not.
> We are making a system to allow others to develop their system.
Indeed. However, we'll still have to build systems,
to test, demonstrate, and host our metasystem.
But indeed we're not very concerned about the details of the system,
as our main goal is to bootstrap a reflective framework.

> This means, we don't put in "protection access specifiers" or come up with
> a "standard HLL format".
We might do the former as an exercise, and the latter as an expedient
bootstrap hack, or dubiously, as a fallback to negociating formats.

> The TUNES system allows high level, detailed
> specification PER OBJECT of what representation it is stored in, how it is
> transmitted across the network, and whether platform-dependent
> representation will be stored along with the object.  We will not add the
> things you speak of.  We will allow people to talk about all these things,
> and choose to do it in the way they think best.
Agreed. Note that "per object" is from the system's point of view;
the system needs not keep the same distinctions and delimitations
between objects as original program sources do,
as long as declared semantics is preserved.

> In my opinion, I believe that these issues (low-level representation and
> distribution formats) will become ones that people no longer deal with.
Except, of course, a few specialists in the matter,
who'll be writing meta-programs to help enhance such things
and combine them with other things, if useful.

> Formats do not affect high-level meaning, and the everyday user does not
> want to deal with them.  The information stored and transmitted will vary
> from system to system, and from minute to minute.  Formats will be
> dynamic and automatic.
Of course, when negociation is not possible, because hosts are disconnected,
and communication happens through slow channels (physically moved disks,
interplanetary radio transmission), then we need some prenegociated
mechanism; but even it can use meta-objects that each adapt the format
of the rest of the message text, instead of a rigid format that is
uniformly unfit to all purposes.

Morever, this is not the "common case", as far as performance is concerned,
neither does it require a "global standard format" to be used uniformly
accross space and time; we only require that every communication channel
have a well-defined communication protocol at any given time; what protocol
is used may completely depend on space-time coordinates.
Wide area, slowly moving standards are still useful to save space
and provide fall-back mechanisms.

> You simply say, "for these objects, keep the
> compiled code cached because I intend to use it often."  Or, more likely,
> you will simply note that you intend to use these objects often, and the
> system will more efficiently determine whether or not to keep the compiled
> code, or delete it and reevaluate the source later.  And, ultimately, you
> won't even have to say you will use the objects often, because the system
> will be able to notice you are using them often, and guess at the future
> based on the past.
Yup.

> You will be able to customize the optimizer behavior
> to any extent you wish.  This is a long way off, however, because someone
> has to design optimization rules, AFTER we make the initial abstract
> reflection tree.
So again, we might need to define a common SLIM binary format,
to bootstrap the system, if we quickly need network distribution of code,
and/or portable/remote debugging facilities.
But ultimately, reflection in the system should allow
automatic meta-programmation to solve most of the problem altogether.


Best regards,

PS: as a side effect of registering Tunes, my shortened WWW address
allowed me to have only 3 lines of standard signature, and leave space
for a automatic quote-of-the-day (here, a manually selected self-quote).

## Faré | VN: Уng-Vû Bân   |    TUNES is a Useful, Not Expedient System     ##
## FR: François-René Rideau | Project for a Free Reflective Computing System ##
## Reflection&Cybernethics  |          http://www.tunes.org/~tunes           ##
A fruitful discussion is a negociation, out of which emerges meaning. Classic
works are Standards, and politeness is a protocol, to ease such negociation.
With a reasonable language, neither is strictly needed, but both sure do help!
		-- Faré