Carl Taylor wrote:

Here's a LOOP version of an index constructor.

(defun make-index-list (obj seq &key (test #'eql))
(loop for p = (position obj seq :test test :start (if p (1+ p) 0))
while p
collect p))

(compile *)

CL-USER 18 >
(make-index-list
'(0 1)
'(a (6 2 z) (0 1) (1 2 3 4) (q w e r t y) (0 1) (foo) bar)
:test #'equal)

(2 5)

Gauche Scheme

(define (make-index-list obj seq :optional (test equal?))
(filter-map
(lambda(x i) (and (test obj x) i))
seq
(lrange 0)))

(make-index-list
'(0 1)
'(a (6 2 z) (0 1) (1 2 3 4) (q w e r t y) (0 1) (foo) bar))

===>
(2 5)

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2024-07-18, B. Pym <Nobody447095@here-nor-there.org> wrote:

Carl Taylor wrote:

Here's a LOOP version of an index constructor.

(defun make-index-list (obj seq &key (test #'eql))
(loop for p = (position obj seq :test test :start (if p (1+ p) 0))
while p
collect p))

(compile *)

CL-USER 18 >
(make-index-list
'(0 1)
'(a (6 2 z) (0 1) (1 2 3 4) (q w e r t y) (0 1) (foo) bar)
:test #'equal)

(2 5)

Gauche Scheme

(define (make-index-list obj seq :optional (test equal?))
(filter-map
(lambda(x i) (and (test obj x) i))
seq
(lrange 0)))

(make-index-list
'(0 1)
'(a (6 2 z) (0 1) (1 2 3 4) (q w e r t y) (0 1) (foo) bar))

(2 5)

This is the TXR Lisp interactive listener of TXR 295.
Quit with :quit or Ctrl-D on an empty line. Ctrl-X ? for cheatsheet.
TXR's no-spray organic production means every bug is carefully removed by hand.

(where (op equal '(0 1)) '(a (6 2 z) (0 1) (1 2 3 4)

(q w e r t y) (0 1) (foo) bar))
(2 5)

--
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* Origin: fsxNet Usenet Gateway (21:1/5)