mailing-list for TeXmacs Users

[Massimiliano Gubinelli <address@hidden>]

Shorter:

(define (find proc list)
 (cond 
  ((null? list) #f)
  ((proc (car list)) (car list))
  (else (find proc (cdr list)))))


Max



> On 5. Jun 2019, at 11:03, Frank <address@hidden> wrote:
> 
> Hello,
> 
> I believe that implementing find procedure by hand is a better option.
> 
> > (define (find proc list)
> >     (define (find-iter head)
> >       (cond
> >         ((null? head) #f)
> >         ((proc (car head)) (car head))
> >         (else (find-iter (cdr head)))))
> >     (find-iter list))
> 
> The filter procedure costs asymptotically more time on average (and 
> probably more space, depending on the implementation).
> 
> Best wishes,
> 
> Le 04/06/2019 à 23:19, Giovanni Piredda a écrit :
>> I need to become acquainted with the different standards :-) (I checked 
>> Guile without realizing that I was checking a different version).
>> 
>> I used the filter function in place of it.
>> 
>> 
>> G.
>> 
>> On 04.06.19 23:06, Massimiliano Gubinelli wrote:
>>> You expect the procedure find to be defined in Guile? I just checked and 
>>> even from the REPL on the command line such function does not belong to 
>>> Guile 1.8. Not all schemes implement the same language. In  particular 
>>> you cannot expect procedures which are not requested by the R5RS standard 
>>> since Guile 1.8 is essentially based on that.
>>> Best
>>> Max
>>> 
>>> 
>>>> On 4. Jun 2019, at 22:19, Giovanni Piredda <address@hidden> wrote:
>>>> 
>>>> 
>>>> On 04.06.19 22:18, Giovanni Piredda wrote:
>>>>> Dear all,
>>>>> 
>>>>> did anyone ever used the find function in the Scheme implementation 
>>>>> used in TeXmacs? It gives me a "Unbound variable: find" error. I can 
>>>>> run the same code from emacs (using MIT-GNu Scheme).
>>>>> 
>>>>> 
>>>> I mean the same code which is giving an error inside TeXmacs
>>>> 
> -- 
> Best wishes!
> Yours,
>