Re: Numeric literals, take 1

On 11/26/2002 8:02 AM, James Mastros wrote:

> Guys, can we please not argue over just how arithmetic and such works 
> for NaN and Inf, and defer to IEEE specs (IEEE-754, AKA IEEE floating 
> point)?  It'll save much argument, and that's how it'll almost 
> certianly be implemented anyway.  Give examples and references, but 
> don't define nonstandard "standard" perl6 semantics when a good 
> standard exists. (I'm looking for a good reference on the IEEE 
> semantics right now, but I'm not having much luck for some reason.) 

(Yes, I'm replying to myself.)

The best reference I can find right now is 
http://research.microsoft.com/~hollasch/cgindex/coding/ieeefloat.html. 
 If anybody has a better one, I'd /love/ to see it.  (IEEE-754 itself is 
non-free.)
(here -N is a negitive number, +N is a negive number, and N is any 
number (but not NaN or Inf).)
N / Inf => 0
Inf / Inf => NaN
# Multipication between infintes follows normal sign rules, and is 
infinite in result.
Inf * Inf => Inf
-N/0 => -Inf
0/0 => NaN
+N/0 => +Inf
Inf - Inf => NaN
Inf * 0 => NaN

All arithmetic ops with any arg NaN results in NaN.  NaN==NaN is NaN, 
which is false.  NaN!=NaN is also NaN, which is false.

    -=- James Mastros