Francois-Rene Rideau rideau@clipper
Sun, 16 Oct 94 21:09:27 MET

> They sound the same.  I'd interpret persistence as the ability of the 
> system to remain running (i.e. no bugs crashing the system) for long 
> periods of time.  I would add to that resilience, the ability to survive 
> the failure of several CPU's which are working on part of an application.

More than that, I'd say persistence would be being able to survive
indefinitely, permanently even beyond power-down (on system that don't have
permanent memory, this means that the complete system state must be regularly
logged on permanent media (say, hard disk).

> I have a different idea about strong dynamic typing.  The basic OS 
> should not concern itself about the content of objects.  This would make 
> the OS very small, and very versatile.  On top of the OS, as part of the 
> applications, ANY level of typing could be used.  I want the OS to be 
> able to serve as many camps as possible.  This way the OS will be a standard 
> building block others can use to explore different programming languages.
That's also how I see it.
But allowing any kind of object is definitely *NOT* enforcing low-levelness
and disabling any kind of typing (as is the case under UNIX where untyped
objects are used).
To me it means being able to parametrize declared objects by there type,
itself parametrized by its the type universe, etc. A very basic (but powerful)
system will provide means to implement any type system inside it; it should
also allow explicit mapping to a set of low-level constructors.

> In order to steer programmers in the direction of dynamic typing I have 
> contemplated a data encapsulation language to enclose parameters being 
> passed between objects.  Objects could use a library of extraction
> functions to pull parameters.  Just an idea though...
That's about what I mean. Again in no case should an object be called with
unproper parameters (or worse even -- parameters that would make a process
or the system crash).

> The gentleman in charge of FIRE e-mailed me today.  Their project is too 
> hardware and language specific for me, although I hope to foster a 
> healthy exchange of ideas with them.
Well, that's the same for me.

> I hope that your goals are close enough to ours so that we can 
> collaborate.  I'll add you to the mailing list and you should receive the 
> first mailing on the 17th.  I hope to hear from you soon.
I hope our collaboration will be fruitful.

Read you soon (:) ,

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