Re: Handling of invalid arguments

[Marc Feeley <feeley@xxxxxxxxxxxxxxxx>]

On 29-Jun-06, at 10:55 AM, Bradley Lucier wrote:

> On Jun 29, 2006, at 9:15 AM, Marc Feeley wrote:
>
> > I have noticed that the specification of flexpt, flsqrt, flatan  
> > and many other procedures may return a meaningless result for  
> > certain ranges of arguments.
>
> I think "that's not a bug, that's a feature," to coin a phrase.  I  
> believe the intention is to let
>
> (flsqrt -1.0)
>
> return whatever the hardware sqrt function returns (a NaN in IEEE  
> 754 arithmetic) rather than
>
> > (sqrt -1.0)
> +1.i
>
> which is what Gambit returns.  I believe the intent is to somehow  
> map the <math.h> C functions to Scheme functions; any author of the  
> SRFI want to comment here?

That was my understanding also.  My comment is that for such cases of  
"invalid arguments" it should be an option to return a meaningless  
flonum rather than a requirement.  If the wording "it is an error" is  
unacceptable, then I can live with giving the option to signal an  
error or return a meaningless flonum.

Marc