320: Add new cond-expand feature to Appendix B: exact-complex

(In this ticket, "complex" is used for readability; it is synonymous with "non-real".)

This feature is true in implementations that support complex numbers such that both the real and the imaginary parts are exact; that is, if (eqv? 3+4i 3.0+4.0i) evaluates to #f. This feature is false if complex numbers are not supported or if only inexact complex numbers are supported. Most of the applications of complex numbers use inexact numbers, but some applications may require exactness: this feature allows those applications to fail fast on implementations that cannot support them.

Existing implementations:

Exact complex numbers: Racket, MIT, Gambit, Chicken with the numbers egg, Scheme48/scsh, Kawa, Chibi, Chez, Vicare, Ypsilon, Mosh, IronScheme, STklos, Wraith
No exact complex numbers: Gauche, Guile, SISC, SCM, Scheme 7, KSi, UMB, Stalin
No complex numbers: Chicken without the numbers egg, Bigloo, Ikarus, RScheme, Scheme 9, Oaklisp, Elk, VX, Sixx, Sizzle, Dream, Owl Lisp, Psyche

cowan

2012-01-05 02:13:22

This is actually in draft 5, but didn't exist when cond-expand was voted on, so we need to vote on it.

cowan

2012-04-05 08:52:00

statusnewdecided

The WG voted to reject this proposal.

cowan

2012-04-07 03:15:39

resolution␣fixed

statusdecidedclosed

Correction: the WG voted to accept this procedure. However, nothing needs to be done, as it is already in the draft.

Ticket 320: Add new cond-expand feature to Appendix B: exact-complex