Re: Numeric literals, take 1

[email protected] (James Mastros) Tue, 26 Nov 2002 08:02:17 -0500
Newsgroups perl.perl6.documentation
Message-ID <[email protected]>
On 11/14/2002 1:58 PM, Angel Faus wrote:
> =section ** Pseudo-Numbers
> 
> =section *** NaN
> 
> The value C<NaN> ("Not a Number") may be returned by some
> functions or operations to signal that the result of a
> calculation (for example, division by zero) cannot be
> represented by a numeric value.
...
> =section *** Inf
> 
> The terms C<Inf> and C<-Inf> represent positive and
> negative infinity; you may sometimes use these to create
> infinite lists.
> 
> For the C<Inf> values, perl will operate them following
> the standard conventions. For example:
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.)

(We need a few additional rules, actualy: NaN is false, and -Inf and 
+Inf are both true.  If either are forced into an int, and error occours 
(? on that last point.)  This whole paragraph might properly be pushed 
off to the discussion of Num in Bool context later.)

	-=- James Mastros