Re: macro defining macros

[Per Bothner <per at bothner dot com>]

Robert Nikander wrote:
> Is there a way to escape the ellipsis so that you can write a macro  
> that defines a macro?  The "standard" is (... ...), but that doesn't  
> appear to work. 

I checked in an implementation for this.  Please try it out.

> Here is a demo of the problem...
>
> ;; macro that creates another macro that quotes its arguments
> (define-syntax mac
>   (lambda (x)
>     (syntax-case x ()
>       ((_ name)
>        (syntax
>         (define-syntax name
>           (lambda (x)
>             (syntax-case x ()
>               ((_ e (... ...))
>                (syntax (quote (e (... ...)))))))))))))
>
>
> (mac mac2)
> (mac2 (1 2 (3))) ----> '(1 2 (3))

Actually, it evaluates to: ((1 2 (3)))
(Petite Scheme yields the same result.)
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/