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Re: arithmetic issues



William D Clinger wrote:
In either case, I think flonums should be in the base
language, because most hardware now supports them much
more efficiently than they could be implemented in a
library module.

I disagree.

Let me give a counter example. I could write an implementation in which flonums are a basic type but flonum operations are not exposed in the base language. That is, in the base language, the standard arithmetic procedures (and probably the procedures that convert to and from external representations) would signal an error if asked to operate on flonums.

I could then implement a library module for the full tower, including flonums. Of course, I would not be able to implement the library module efficiently in the base language, but as I'm the implementor that is not a real problem -- I define the extensions I need and make them available to the library module.

So, it is possible to have an efficient implementation of flonums in the library without forcing them to be exposed in the base language.

Regards,

Alan
--
Dr Alan Watson
Centro de Radioastronomía y Astrofísica
Universidad Astronómico Nacional de México