[CM] symbol-value (was: 2 questions)
Orm Finnendahl
finnendahl@folkwang-hochschule.de
Sat, 19 Oct 2002 20:38:18 +0200
Hi Thorsten,
are you working in Belfast now?
Am Samstag, den 19. Oktober 2002 um 00:30:07 Uhr (+0200) schrieb
Torsten Anders:
> Am Donnerstag den, 17. Oktober 2002, um 18:00, schrieb Orm Finnendahl:
> >2. How can I access the symbol-value of a symbol?
>
> Sorry, perhaps I misunderstood something. But so far as I know there is
> only one symbol binding in Scheme (unlike the seven bindings in CL).
> Therefore you should not need a symbol-value at all -- just evaluate, as (I
> did not checked the code...):
>
>
> (begin
> (define *a* 3)
> (define *b* 23)
> (define my-seq (list *a* *b*)) ; no quote here!
> (loop for x in my-seq
> collect x)
> )
>
Well, as stated before, that doesn't really help if you're concerned
with dynamic change of the meaning of a certain symbol during the
course of the process. I'd rather store references of things than the
things themselves in the cycle. It could be done with lisp-ref, of
course, but that has other disadvantages.
> BTW: is there a loop in Scheme?
Yes and no. Rick has implemented all or at least most of its
functionality in a file called loop.scm and in the formerly mentioned
slib there is an implementation of loop and, among others, also a
complete implementation of format.
--
Orm