[plt-scheme] Macros that expand to macro definitions

Thanks a lot!

-Arjun

On Tue, 26 Jul 2005, Jens Axel Søgaard wrote:

> For list-related administrative tasks:
> http://list.cs.brown.edu/mailman/listinfo/plt-scheme
>
> Arjun Guha wrote:
>>  For list-related administrative tasks:
>>  http://list.cs.brown.edu/mailman/listinfo/plt-scheme
>> 
>> This (contrived) example doesn't work:
>> 
>>   (define-syntax (foo stx)
>>     (syntax-case stx ()
>>       [(_ foo-expr ...)
>>        #`(begin
>> 
>>            (define-syntax (bar stx)
>>              (syntax-case stx ()
>>                [(_ (bar-expr ...))
>>                 #'(begin
>>                     (printf "~a~n" 'bar-expr) ...)]))
>> 
>>            (bar foo-expr) ...)]))
>> 
>> I get:
>> 
>> Welcome to DrScheme, version 299.106-svn16jun2005.
>> Language: (module ...).
>> syntax: no pattern variables before ellipses in template in: ...
>> 
>>> 
>> 
>> However, if I remove the ellipses, so that the pattern for the inner bar 
>> macro is (_ (bar-expr)), it works just fine.  Is there any way to use ... 
>> in bar?
>
> You need to write them as (... ...).
>
> -- 
> Jens Axel Søgaard
>