Re: flames!

[Kent Dybvig <dyb%unc.csnet@csnet-relay.arpa>]

     (if (if p q) r s)

Could of course be written:
     (if (if p q #!true) r s)


"unless" is a handy special form, in addition to "when":
     (unless (zero? x) (set! x (/ 1 x)))
would have to be written as:
     (when (not (zero? x)) (set! x (/ 1 x)))
or (shudder):
     (if (not (zero? x)) (set! x (/ 1 x)))

It has always bothered me that the "else" part was optional
in the one-or-two-armed-if.  Why can't the "then" part be
optional as well?  

"when" and "unless" are clean, simple, and unambiguous.  They
should both be included in the standard.