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[Giovanni Piredda <address@hidden>]

Thanks to both.


Right now I am searching for an element in a list of a few, so different 
implementations make unappreciable differences, but it is nice to have 
an efficient implementation.


Giovanni


Am 05.06.2019 um 11:20 schrieb Massimiliano Gubinelli:
> 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,