[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Wrapping up SRFI-70



Aubrey Jaffer wrote:
I believe that the junking of 0/0 makes SRFI-70 compatible with
IEEE-754.  Do you agree?

It's a bit awkward.  The syntax 0/0 suggests 0/0 is exact.
The 0/0 syntax is extra awkward for an implementation that
defines 1/0 and -1/0 as exact infinities, as Kawa does.

(Exact infinites are an experimental addition in Kawa  I won't claim
they're terribly well-specified or justified.  I think they can be
useful in some situation, such as sentinel values.)

I did find some discrepencies between your specification and Kawa:

#|kawa:21|# (define neg-inf (/ -1.0 0.0))
#|kawa:22|# neg-inf
#i-1/0
#|kawa:23|# (log neg-inf)
#i1/0+3.141592653589793i
#|kawa:26|# (sqrt neg-inf)
#i+1/0i

Kawa allows complex numbers with infinite components.
Whether this is "correct" or accidental I don't know.

Also I got:

#|kawa:29|# (angle inf)
0
#|kawa:30|# (angle neg-inf)
0
--
	--Per Bothner
per@xxxxxxxxxxx   http://per.bothner.com/