Re: Given string 'a.bc.' -- replace each dot(.) with 0 or 1

Madhu <enometh@meer.net> writes:

* HenHanna <v29p14$2mr5l$2@dont-email.me> :
Wrote on Sat, 18 May 2024 01:31:32 -0700:
>

< > How can i write this function simply?   (in Common Lisp)
< >
< > -- Given a string  'a.bc.'   -- replace each dot(.)  with 0 or 1.
< >
< >        -- So the value is a list of 4 strings:
< >                                  ('a0bc0'  'a0bc1'  'a1bc0'  'a1bc1')

>
(defun adjusted-logbitp (pos num total-width)
  (let* ((int-len (integer-length num))
(i (- pos (- total-width int-len))))
    (if (< i 0)
nil
(logbitp i num))))
>
(defun bindots (str)
  (let* ((indices (loop for c across str for i from 0
       if (eql c #\.) collect i))
(width (length indices)))
    (loop for i below (expt 2 width)
  collect (let ((ret (copy-seq str)))
    (loop for j in indices
  do (setf (aref ret j)
   (if (adjusted-logbitp j i width)
       #\1
       #\0)))
    ret))))

what about substitute? common lisp is not scheme of the week.