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missing Lisp world (was: Re: puzzle with string permutations [photo])
From: |
Emanuel Berg |
Subject: |
missing Lisp world (was: Re: puzzle with string permutations [photo]) |
Date: |
Wed, 08 Jun 2022 04:52:30 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) |
This code BTW illustrates the strategic weakness we have had
for a long time, since day one actually from my perspective
anyway, namely that we've had and have an Emacs world which
contains Lisp (Elisp), but what we should have is a Lisp world
and Emacs would be one of many components of that world!
> (require 'cl-lib)
>
> (defun cl-faculty (n)
> (cl-loop with prod = 1
> for i from 2 to n do
> (setq prod (* i prod))
> finally return prod) )
> ;; (cl-faculty 5) ; 120
> ;; (cl-faculty 10) ; 3 628 800
>
> (defun count (e l)
> (seq-count (lambda (elem) (= elem e)) l) )
> ;; (count ?o '(?d ?g ?o ?o)) ; 2
>
> (defun product-string (str)
> (let*((str-list (string-to-list str))
> (str-list-no-dups (cl-remove-duplicates str-list))
> (prod 1) )
> (dolist (e str-list-no-dups)
> (setq prod (* prod (cl-faculty (count e str-list)))) )
> prod ))
> ;; (product-string "ogod") ; 2
>
> (defun perms-string-num (str)
> (let ((n (cl-faculty (length str)))
> (r (product-string str)) )
> (/ n r) ))
> ;; (perms-string-num "ogod") ; 12
> ;; (perms-string-num "kudtce") ; 720
--
underground experts united
https://dataswamp.org/~incal
- puzzle with string permutations [photo], Emanuel Berg, 2022/06/07
- Re: puzzle with string permutations [photo], Marcin Borkowski, 2022/06/07
- Re: puzzle with string permutations [photo], Emanuel Berg, 2022/06/07
- Re: puzzle with string permutations [photo], Emanuel Berg, 2022/06/07
- Re: puzzle with string permutations [photo], Emanuel Berg, 2022/06/07
- Re: puzzle with string permutations [photo], Emanuel Berg, 2022/06/07
- Re: puzzle with string permutations [photo], Emanuel Berg, 2022/06/07
- Re: puzzle with string permutations [photo], Yuri Khan, 2022/06/07
- Re: puzzle with string permutations [photo], Emanuel Berg, 2022/06/07
- Re: puzzle with string permutations [photo], Emanuel Berg, 2022/06/07
- missing Lisp world (was: Re: puzzle with string permutations [photo]),
Emanuel Berg <=
Re: puzzle with string permutations [photo], Emanuel Berg, 2022/06/07