| Date: Tue, 09 Aug 2005 22:13:23 -0700 | From: Per Bothner <[EMAIL PROTECTED]> | | I think there are some good things here, but there may be too much | stuff in one SRFI. | | .... | | An SRFI dealing with inexact infinities should I think focus more | on IEEE infinities. It is desirable that a Scheme implementation | can map (possibly compile) Scheme arithmetic on inexact reals into | IEEE floating-point arithmetic. I think more dicussion of this | issue is needed.
The current (2005/08/12) revision of SRFI-70 makes clear that +inf.0 and -inf.0 correspond to the IEEE-754 infinities already supported by nine implementations of Scheme. | Date: Tue, 09 Aug 2005 22:36:32 -0700 | From: Per Bothner <[EMAIL PROTECTED]> | | The rationale discusses NaN, but I think the solution that | 0/0. = 0/0. is wrong. I think it is important to be compatible | with IEEE, and that 0/0. be the same as NaN. 0/0 is now an optional error object, completely unconstrained by SRFI-70. | The Kawa solution (which I think is the right one): | | (define NaN ...) | (= NaN NaN) => #f | (eq? NaN NaN) => #t | (eqv? NaN NaN) => #t | (equal? NaN NaN) => #t | | This may technically violate R5RS, but I think it's the | best choice if we want to be compatible with IEEE, which | think we do. I believe that the junking of 0/0 makes SRFI-70 compatible with IEEE-754. Do you agree?
