[racket] numbers/bytes in r6rs

At Sun, 26 Dec 2010 10:49:45 -0600,
Matthew Flatt wrote:
> > - determining whether a floating point number is a double or a single.
> 
> I don't think there's any predicate for that.

flonum? returns true for double-precision floats, and
(lambda (x) (and (inexact-real? x) (not (flonum? x))))
returns true for single-precision floats (if Racket was compiled with
single-precision float support).

Vincent