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Re: external representations



bear wrote:
On Sat, 18 Jun 2005, William D Clinger wrote:

2.  The proposed 1/0 and -1/0 syntax for infinities
has two related problems: it looks like these things
are exact, and allowing this syntax will require a
more complicated rule for deciding whether a numeric
literal is exact or inexact.

3.  The +inf.0 and -inf.0 syntax is already used by
several implementations, which agreed to standardize
upon it several years ago, before the SRFI process
began.  Th +inf.0 and -inf.0 syntaxes (and +nan.0)
also appear within The Revised R6RS Status Report of
October 2004, which is online at www.schemers.org.


I agree with this, by the way: I'd much rather see
+inf.0 and -inf.0 than 1/0 and -1/0.  To me the
connotations are different:  +inf.0 means "numeric
overflow:"  1/0 means "illegal operation."  Or,
mathematically, +inf.0 seems to mean "we can't tell
how big this is, and it may be infinite" and 1/0
means "this is, exactly and absolutely, a first-order
infinity."  I find +inf.0 and -inf.0 seem to me to
express the ideas that are more in line with the way
they are used in computer programs. Besides, they
are already used by more implementations than 1/0
and -1/0.

I too agree. Due to my day job, as soon as I see 1/0
I begin to look for the red pencil.

--
Jens Axel Søgaard