From Newsgroup: comp.lang.scheme

On 5/19/2024 11:36 AM, Joerg Mertens wrote:

HenHanna <HenHanna@devnull.tb> writes:

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')

-- The order is not important.
If the string has 3 dots, the value is a list of length 8.

If the program is going to be simpler,
pls use, e.g. (a $ b c $) rather than 'a.bc.'

Another one:

(defun subst-dots (s &optional (pos 0))
(let ((p (search "." s :start2 pos)))
(if p
(append
(subst-dots (replace (copy-seq s) "0" :start1 p) (1+ p))
(subst-dots (replace (copy-seq s) "1" :start1 p) (1+ p)))
(list s))))

Regards

Nice... Thanks !
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