Re: [pure-lang-users] complex 0

[Albert G. <Dr....@t-...>]

John Cowan wrote:
> Division with slash effectively promotes its arguments to floats, so
> 0.0 should be promoted to 0.0+:0.0.

Good point! In fact gcc seems to do that, too (I get nan+:nan for /0.0 
just as well as for /(0.0+I*0.0).

However, that's *not* what ISO/IEC9899, Annex G [1] says (see G.5.1, 
especially Example 2). It requires an inf+I*inf result in the /0.0 case, 
if I read it right. That has the "informative" sticker (i.e., 
"recommended" but not "normative"), so implementations may differ. 
AFAICT, my implementation in math.pure conforms with Annex G (at least 
the multiplicative operators, still have to check the others). So I 
guess I'll just leave it at that for now.

[1] I'm referring to the 2005 draft, couldn't find anything newer. 
Here's the URL: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf

Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr....@t-..., ag...@mu...
WWW:    http://www.musikinformatik.uni-mainz.de/ag