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From: "B. Pym" <Nobody447095@here-nor-there.org>
Newsgroups: comp.lang.lisp
Subject: Re: Loop? ptooey
Date: Fri, 20 Jun 2025 22:45:03 -0000 (UTC)
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> Kenny Tilton wrote:
> 
> > > KMP: The example you cite is quite simplistic.....snip...A
> > > loop like this: 
> > > 
> > >            (loop for x from 0 
> > >                  for y in some-list 
> > >                  when (good-result? y) 
> > >                    collect (list x y)) 
> > > 
> > > is easy to write and maintain, and much easier to explain than the
> > > equivalent, but more Lispy:
> > > 
> > >            (do ((x 0 (+ x 1)) 
> > >                 (y-list some-list (cdr y-list)) 
> > >            (result '())) 
> > >               ((null y-list) ;; [fixed] 
> > >                 (nreverse result)) 
> > >            (let ((y (first y-list))) 
> > >               (when (good-result? y) 
> > >                 (push (list x y) result)))) 
> > 
> > Ugh. Howse about: 
> > 
> > (let ((goody-pos -1) 
> >        goodies) 
> >     (dolist (it some-list (nreverse goodies)) 
> >       (incf goody-pos) 
> >       (when (good-result? it) 
> >         (push (list goody-pos it) goodies)))) 
> > 
> > perhaps i will be swayed someday by the charms of loop, but i gotta
> > tell you, i just don't get it. is loop for people who can't read lisp?
> > can't be, lisp is easier to read than loop. stumped.

Gauche Scheme:

(use gauche.collection)   ;; size-of

(filter-map
  (lambda (x i)
    (and  (> (size-of x) 1)  (list i x)))
  '("a" "or" "I" "can" "o" "burn")
  (liota))

  ===>
((1 "or") (3 "can") (5 "burn"))