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Re: external representations

This page is part of the web mail archives of SRFI 70 from before July 7th, 2015. The new archives for SRFI 70 contain all messages, not just those from before July 7th, 2015.

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