Re: Disallowing Pre-Defined Operations

["Robert I. Eachus" <rieachus@earthlink.net>]

Robert Dewar wrote:
  
> I see a lot of people hypothesizing that this would be a useful
> feature that would sell Ada, but as we all know in CLA, there
> is that kind of support for almost any imaginable feature in
> Ada. What would be more interesting is specific war stories that
> we could analyze to see how an additional feature might have
> helped.

   There is a general-purpose feature that could be added to compilers,
and which is already
explicitly allowed for by the Ada 95 standard.  If compilers were to
provide a non-standard
integer and non-standard floating point type with literals, assignment
and, I think, no other operations, then implementors could provide
various packages to provide SI unit checking, unbounded numeric types
with literals and so on.  Hmmm.  The 'SIZE attribute is key, and needs
to be user settable.  Conversion of literals in source code should, in
effect, use the same routines as for the largest integer and float
types.  If hundred-digit values need to be built
at compile time, that could be left to the programmer, but it is a pain
not to be able to use
literals for zero, one, and two.