Re: Numeric literals, take 1

[email protected] (Michael Lazzaro) Tue, 26 Nov 2002 08:55:04 -0800
Newsgroups perl.perl6.documentation
Message-ID <[email protected]>
On Tuesday, November 26, 2002, at 05:02  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

Yes and no.  perl6-internals has been discussing this, so I think we 
can pause and not worry about it quite yet.  Floats will almost 
certainly be IEEE, but in addition to floating point ("num", aka C 
"double"), most of the same issues exist for sized integers, both 
signed and unsigned.  Worse, the behaviors are platform-dependent.

For example, what happens when you add two 8-bit numbers, and the 
result is no longer an 8-bit number, e.g. 'overflow'?  (We may indeed 
have access to a type called 'int8', since Parrot will likely have it.)

    my int8 $i = 254;
    my int8 $j = 254;

    $i += $j;   # ???

Does it overflow (via an exception?), silently truncate, or ?.  (Parrot 
may offer us both options.)  We can choose to call the result "platform 
dependent", or define it explicitly.  But let's wait and see what the 
Parrot people think, since they're closer to the action.

MikeL