Re: straw-man [was Re: arithmetic issues]
Paul Schlie 22 Jan 2006 03:34 UTC
> From: bear <xxxxxx@sonic.net>
>> On Fri, 20 Jan 2006, William D Clinger wrote:
>> Secondly, the standardization of the fixnum/flonum base
>> will improve the portability of programs that, for whatever
>> reason, already use implementation-specific fixnum or flonum
>> operations.
>
> Erf.... Aesthetics aside, yes, it *is* correct, if you're
> going to have these modular-ring fx-foo and limited-precision
> fl-foo operations, to make them different from general numeric
> operations. This is because they are different operations
> from the general numeric operations, and in some circumstances
> give different answers.
> ...
- Upon more reflection, given that it's likely unreasonable to presume
that an <exact> implementation must (or even could) reliably support
infinitely precise calculations/representations, it must then support
finite precision calculations, thereby necessitating its definition
of overflow semantics, basically leaving the choice of either modular
or saturating semantics; where either may be considered reasonable,
it seems undisputed that modular semantics tend to be the simplest
and most natural default of most machine and/or SW implementations,
and does not preclude the throwing of a recoverable overflow exception
if supported by the base implementation.
(although believe exposing explicitly typed functions are unnecessary)