Re: newbie Q: storage management

[bobduff@world.std.com (Robert A Duff)]

In article <dewar.862915787@merv>, Robert Dewar <dewar@merv.cs.nyu.edu> wrote:
>In other words, the really strong argument for a GC annex would be if
>you now saw a situation in which lots of Ada 95 vendors were rushing to
>implement GC in an incompatible manner. I don't see that happening yet :-)

I agree with Robert here.  Look at the Real Time Annex: The idea was
that most of the Ada 83 vendors (or at least most of the ones who were
going after the real-time market) were providing more-or-less the same
functionality, but in incompatible ways.  The reason the RT annex was
invented, was to encourage compatibility.

In general, it is *not* the purpose a language standard to force
implementers to produce good products.  The purpose is to ensure
uniformity across implementations.  After all, the whole Ada standard is
completely optional -- if you want, you can write a compiler for an
Ada-like language that you think is "better" than Ada in some way.  Or
you can write a compiler for a subset of Ada.  The standard doesn't
force you to support all the features of Ada -- your customers with
money to spend are the ones doing the forcing.

So it would be inappropriate, and ineffective, to have a GC Annex that
somehow said "Thou shalt have GC" (even if one could produce a
precise-enough definition of what it means to "have GC").  The only
purpose of a GC annex would be to standardize whatever hooks there are
(such as procedures for turning it off and on, specifying how many
generations you want, and so forth).  But even within the GC community,
there are strong disagreements about what such hooks ought to look like
-- some people don't like generational GC, so what's that hook supposed
to mean?

- Bob