Tangentialy, can I suggest that a nicer synthax might be -Inf..-1 / 1..Inf,
etc.
Assuming that we end up supporting full IEEE floats, this becomes the
"obvious"
synthax, and I find C<(-Inf..Inf)> to be far more clear then C<(..)>. We've
got
plenty of puncuation already, thank you very much.
Also, can someone please suggest a reasonable implementation of (-Inf...-1)?
If not, can I suggest that we require that if one of the arguments to (list)
.. s +/-infinity, it be the second one, and additionaly say that a..b is the
list , a+1, a+2, ... b if b>a, and a, a-1, a-2, ... b if a>b. This would
allow the full expressiveness of both (-inf..0) and (0..inf) without ever
having an infinite starting point to a list.
(If a..b where a==b, then we get the list containing only a.)
In any case, (-inf...-1) would "obviously" either:
begin with the smallest negitive integer representable,
or begin with the IEEE -inf.
If it begins with the IEEE -inf, then it has to continue with an infinite
number of -infs, since
-inf+1=-inf (a rule of IEEE arithmitic).
Ergo, it is useless to begin at -inf unless perl6 becomes _very_ good at
finding out what you "really" meant.
OTOH, having it begin with the smallest non-(negitive)infinite value means
that it becomes non-infinite,
IE scalar((-inf..0)) != inf. This is obviously a Bad Thing. Also, if
bignums are intergrated (as has been proposed),
then there is no smallest representable integer.
(This assumes that the float synthax will be extended to include "NaN" and
"Inf" as valid
floating-point numbers. (This does take away from non-reserved namespace.)
Has this
been proposed yet?)
-=- James Mastros,
In slightly over his head.
