Keyword arguments in R7RS

Things are getting spicy.
[quote]
Neil Van Dyke
To get the keyword arguments discussion started, I'll provide a quick,
loosely-defined strawperson...
* Keywords look like ":foo", "foo:", or "#:foo", depending on your dialect.
* The main use of keywords is to name "keyword arguments" in procedure
applications and syntax uses, such as for optional arguments or for clarity.
* "lambda" is extended to permit keyword arguments to be defined, each
of which argument may have a default value.  The argument is optional
iff a default value was defined.
* The various syntax definition forms should permit syntax transformers
to be keyword-aware as well.
* Example:
(define f (lambda (a b c (:foo 42) :bar)  foo))
(f 1 2 3 :foo 4 :bar 5) ==> 4
(f 1 2 3 :bar 5) ==> 42
(f 1 2 3) =error=> :bar keyword argument required
(f 1 2 3 :foo 4 :bar 5 :zoo 6) =error=> unrecognized keyword :zoo
* Note: If keywords are first-class values, and you want to pass a
keyword as an argument in an application in a position in which it might
be parsed as a keyword, you cannot put  a keyword literal into the
application syntax directly.
* I probably wouldn't have keyword arguments in WG2, but their
implementation in WG2 would likely impose requirements on WG1.
--
[/quote]

Working Group 1 thread:
https://groups.google.com/group/scheme-reports-wg1/browse_frm/thread/3c0c5a48a520f32d
or
Working Group 2 thread:
https://groups.google.com/group/scheme-reports-wg2/browse_frm/thread/4f4b2a9a0eb86450

...what do the resident clispers in prague think? Should they exist in the core language or should we have a supplementary (i.e. "defun" in all its glory) macro for WG2 Scheme?

Keyword arguments are messy but useful; I'd support them in WG2 but not WG1. One fundamental problem with keywords is that they don't obey lexical scope, and that always causes name clashes as soon as you start to combine things. I like SRFI 39 because it obeys lexical scope, and you can use parameters like keyword arguments in many situations. I would welcome SRFI 39 to WG1 and WG2, but it's not essential like SRFI 9.
While keyword arguments probably won't make it in WG1, optional arguments might. Riastradh has a nice proposal at <http://mumble.net/~campbell/proposals/optional.text>;.