[plt-scheme] Macro question
Benderjg2 at aol.com wrote:
> In a message dated 5/23/2003 10:13:07 PM Central Daylight Time,
> mcj4 at ukc.ac.uk writes:
>
>
>>I get a complaint about #%app not being bound, in particular with respect
>>to my calls to
>>'vector-ref'. I've read the docs on this a few times; I don't think it's
>>unclear, but I do think I
>>don't understand.
>
>
> This error message should be really read as "macro messed with the hygiene;
> the module system detects that the author got the hygiene marks wrong" ;)
Although I sometimes see this error message even when I'm not messing with
hygiene.
Eg.
(define-syntax id
(let-syntax ((never-used (syntax-rules ())))
(syntax-rules ()
((_ e) e))))
compile: bad syntax; function application is not allowed, because no #%app
syntax transformer is bound in: (syntax-rules ())
Is this a bug perhaps? Scheme48 happens to accept it.
-d