syntax-case guards

[Aleix Conchillo Flaqué]

Hi,

I'm trying to use a syntax-case guard when the pattern has ellipsis.
So I have something like,

      ((_ (struct (k v) ...))
       (string? (syntax->datum #'k))
       exp)

And I want k to be a string. However, I am getting this error:

missing ellipsis in form (syntax k)

In ice-9/boot-9.scm:
   106:20  0 (#<procedure 297a240 at ice-9/boot-9.scm:97:6 (thrown-k .
args)> # …)

For patterns without ellipsis it works great.

So, how do I make the guard when I have a pattern with ellipsis?

Thanks in advance,

Aleix