[r6rs-discuss] [Formal] The implicit cond in guard expressions is not a good idea

From: Michael Sperber <sperber>
Date: Sun Nov 19 13:44:46 2006

Trent Buck <trentbuck_at_gmail.com> writes:

> I personally find the suggested GUARD syntax more "natural" than the
> one in 5.91, but I'm not convinced it is necessary at all.
>
> AFAICT it's only real purpose is to allow users to omit a couple of
> LAMBDAs, i.e.
>
> (guard X Y Z ...)
> ---> (with-exception-handler (lambda (X) Y) (lambda () Z ...))

No. You might check the reference implementation in:

http://srfi.schemers.org/srfi-34/srfi-34.html

for details.

> A user can add this herself with a simple SYNTAX-RULES.

While this isn't true in this particular case, it is hardly an
argument for omitting `guard'. It is true for, say, `and', but `and'
is such a common idiom that it makes sense including it in the
standard.

-- 
Cheers =8-} Mike
Friede, V?lkerverst?ndigung und ?berhaupt blabla
Received on Sun Nov 19 2006 - 05:37:18 UTC

This archive was generated by hypermail 2.3.0 : Wed Oct 23 2024 - 09:15:00 UTC