[R6RS] 3 things we may want to vote on

Michael Sperber sperber
Wed Jun 8 02:49:11 EDT 2005

Let me say clearly that I only had the impression we were ready to
vote on these issues, not that I expected us to vote yes on all of
them, or that I had any special stakes in the outcome.

William D Clinger <will at ccs.neu.edu> writes:

>> - Make continuations created by BEGIN accept multiple values?
> I would vote "yes" on this.  It would not break any portable code.
>> http://mailman.iro.umontreal.ca/mailman/private/r6rs/2004-October/000267.html
>> Two decisions, actually, the second one on specifying primitives to
>> return zero values.
> I'm against this.  Changing existing primitives to return zero
> values would break some R5RS-portable code, e.g. the following
> macro-expansion of BEGIN:
>     (begin E1 E2 E3 ...)
>  => ((lambda (ignored) (begin E2 E3 ...))
>      E1)
> You can't dismiss this as merely pedagogical, since my Twobit
> compiler expands BEGIN forms in essentially this way.  Others
> have written similar code.

I'm confused.  Aren't you arguing against the first decision here?

>> - Make -> a valid identifier?
> I have no problem with this, although I don't recall the
> motivation for it.

Most but not all Scheme implementations already support it, and,
consequently, it's pretty popular in programs, especially when writing
forms denoting types.  

But there are other examples: SRFI 14 currently isn't R5RS because it
defines a binding ->CHAR-SET.  Scheme 48, which is otherwise picky
about R5RS extensions, even has this in the reader:

(define strange-symbol-names
  '("+" "-" "..."
	"->"	    ;Only for JAR's thesis

Cheers =8-} Mike
Friede, V?lkerverst?ndigung und ?berhaupt blabla

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