Re: Ada Annex E (Just curious :-)

["Marin David Condic" <marin.condic.auntie.spam@pacemicro.com>]

"Randy Brukardt" <randy@rrsoftware.com> wrote in message
news:_Mup6.4125$7e6.1607402@homer.alpha.net...
> No, no, no. Annex E provides a standard package for all of that stuff
> (see E.5), the compiler is required to allow the user to change that
> package (and the ACATS tests do exactly that).
>
> So it had better be implementation-independent.
>
O.K. I stand corrected. I'm not as familiar with Annex E as maybe I should
be, it appears. :-)

What you're saying is that you'd do some sort of extension to System.RPC and
fill in the read/write/do_rpc stuff? The dispatching handles the rest? That
would go a long way to making it fairly easy to modify the behavior to get
what you want.

Now your only issue would be efficiency - and of course that's always an
issue that is going to depend on the quality of the compiler in question
anyway. The best you could do is have some benchmark programs & run some
tests...

> It is true that marshalling and unmarshalling can be a problem. That
> usually can be handled with overrides to 'Read and 'Write. (Indeed, that
> is a major reason that they can be overridden).
>
I've had representation issues with the 'Read and 'Write stuff before. I've
also expressed complaints about its efficiency. I suppose if I were molding
all this stuff to a specific environment I might resort to assembly code if
I couldn't get around the Ada rules. It would be ugly, but it might get the
job done.

In general, I've not been 100% happy with the behavior of streams and the
'Read & 'Write stuff. It may be fine for things that are done with the same
compiler/hardware/os at both ends and where speed is not a critical issue.
Where things get heterogeneous and you have performance issues, I think the
requirements for that part of Ada are not very user friendly (at least if
the user is me! :-) One might say "A Solution Does Exist" - but I might
retort "It Would Be Difficult."

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
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