[r6rs-discuss] Spec Size and Numeric Tower

From: Neil Jerram <neil>
Date: Thu Sep 28 04:06:42 2006

"Blake Coverett" <scheme_at_bcdev.com> writes:

> Implementations of Scheme are required to implement the whole
> tower of subtypes given in section 2.1.
>
> This puts a large burden on various specialized implementations.

Why is that? I would have thought that the only effect of the new
requirement would be that a specialized implementation could not say
"This implementation conforms to R6RS." It would have to say instead
something like "This implementations conforms to R6RS, except that it
only implements exact fixnums, not the whole numerical tower." That
doesn't seem like a large burden.

> In fact, I would argue that the overall domain of applications for
> which nothing but exact fixnums would suffice is larger that the
> domain requiring any complex numbers at all.

That may well be true. But surely the point of a standard is that
someone can write a Scheme program that does use many of the described
features, and then know that this program will run on any
implementation that says it is R6RS compliant?

Regards,
     Neil
Received on Thu Sep 28 2006 - 04:06:27 UTC