| Date: Wed, 23 Sep 2009 07:44:54 -0500 | From: "Brian Mastenbrook" <[email protected]> | | On Wed, 23 Sep 2009 01:53:31 -0500, John Cowan <[email protected]> wrote: | | > Since R3RS, Scheme has had notation for specifying more than one | > precision of inexact numeric constants. R4RS standardized the | > current notation of replacing the normal E of exponential | > notation with the flags S (short), F (single), D (double), and L | > (long), and most Schemes support all these syntaxes. However, | > all Schemes I can find provide, in fact, only one precision | > (which I conjecture to be IEEE double in all cases), so all these | > flags are useless to programmers. I propose that they be dropped | > in R7RS. | | I'm curious about why no Scheme provides IEEE single floats. It | doesn't seem to be an intrinsically Scheme design decision, and as | you point out all extant Common Lisp implementations provide them. | Would any implementors care to comment?
SCM encodes any inexact real x which is equal to its signle-precision value as a single-precision float. A single-precision float and its type header fits within a cons-cell, which saves space compared to a boxed double-precision float. _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
