Re: is there a version of unix written in Ada

[Paul Rubin <no.email@nospam.invalid>]

Brian Drummond <brian@shapes.demon.co.uk> writes:
> The Rekursiv's own language, Lingo... prove[d] that type safety and
> dynamic binding are not mutually exclusive, and that hardware support
> enforcing at runtime a lot of correctness [1] that Ada-95 did later at
> compile time, was possible.

1) I don't know if the Rekursiv predated the Lisp machine, but maybe
that did about the same?

2) Runtime checks don't really "count" for critical applications.  They
just ensure an orderly runtime crash if a type error manifests, but Ada
is designed for writing applications that are simply not allowed to
crash.

3) I wonder where the iAPX-32 comes into this.  I think it was designed
to run Ada, but I don't know much more about it.  It turned out to be
complicated enough that it had to be spread across 3 chips using the
process technology of the time, and the inter-chip communication made it
too slow to use.  But I wonder, these days, if a single chip
implementation would take as large a speed hit vs. conventional
architectures as the 3 chip version did.