Re: verify ISSN (issn-verify.el)

[황병희]

Emanuel Berg via "Emacs development discussions." <emacs-devel@gnu.org>
writes:

> ;;; issn-verify.el --- verify ISSN -*- lexical-binding: t
> ;;
> ;;; Commentary:
> ;;
> ;; This Elisp package provides functions to verify
> ;; ISSN by computing their check digits.
> ;;
> ;; Author: Emanuel Berg (incal) <moasenwood@zoho.eu>
> ;; Created: 2020-09-06
> ;; Keywords: bib, tex
> ;; License: GPL3+
> ;; Package-Requires: ((cl-lib "1.0"))
> ;; URL: https://dataswamp.org/~incal/emacs-init/issn-verify.el
> ;; Version: 1.0.0
> ;;
> ;; Also see:
> ;;
> ;;   https://dataswamp.org/~incal/emacs-init/isbn-verify.el
> ;;
> ;; To install this package, with this file in
> ;; a buffer, do:
> ;;
> ;;   M-x load-file RET RET
> ;;
> ;; International Standard Serial Number:
> ;;
> ;;   ISO 3297, 1975
> ;;
> ;; format:
> ;;
> ;;   The Ring Magazine: ISSN 0035-5410
> ;;   d_1d_2d_3d_4-d_5d_6d_7c
> ;;   d_i for i \in [1, 7] is an integer
> ;;   c, the check digit, is 0..9 or X for 10
> ;;
> ;; compute check digit c:
> ;;
> ;;     c' = 8d_1*7d_2*6d_3*5d_4*4d_5*3d_6*2d_7 mod 11
> ;;
> ;;         { 0        c' = 0
> ;;     c = {
> ;;         { 11 - c'    else
> ;;
> ;;; Code:
>
> (require 'cl-lib)
>
> (defun issn--get-digits (issn)
>   (when (string-match "[[:digit:]]\\{4\\}-[[:digit:]]\\{3\\}[X[:digit:]]" 
> issn)
>     (let*((hyphen-pos 4)
>           (issn-lst   (string-to-list issn)) )
>       (mapcar (lambda (c) (if (eq ?X c) "X" (- c ?0)))
>               (append (cl-subseq issn-lst 0 hyphen-pos)
>                       (cl-subseq issn-lst (1+ hyphen-pos)) )))))
>
> (defun issn-verify-issn (issn)
>   (let*((issn-lst (issn--get-digits issn))
>         (c-prop  (car (last issn-lst)))
>         (c-w 0) )
>     (cl-loop for d in issn-lst
>              for w downfrom 8 to 2
>              do (cl-incf c-w (* w d)) )
>     (let*((c-prime (mod c-w 11))
>           (c       (cond ((= c-prime  0) 0)
>                          (t (- 11 c-prime) )))
>           (c-x     (if (= 10 c) "X" c)) )
>       (if (equal c-prop c-x)
>           (message "%s (OK)" c-x)
>         (message "NOT OK! is %s, should be %s" c-prop c-x) ))))
>
> ;; Bicycle Quarterly   (issn-verify-issn "1941-8809")
> ;; Bicycling           (issn-verify-issn "1651-9744")
> ;; Black Belt          (issn-verify-issn "0277-3066")
> ;; Filter              (issn-verify-issn "1654-9813")
> ;; Linux Pro           (issn-verify-issn "1471-5678")
> ;; National Geographic (issn-verify-issn "2535-4124")
> ;; Outside             (issn-verify-issn "0278-1433")
> ;; The Ring            (issn-verify-issn "0035-5410")
>
> ;; The Economist       (issn-verify-issn "0013-0614") ; NOT OK! is 4, should 
> be 3
>
> (provide 'issn-verify)
> ;;; issn-verify.el ends here

Still i don't know emacs lisp but your codes looks beautiful, wow!!!
Cheer up and thanks Emanuel^^^

Sincerely, Byung-Hee

-- 
^고맙습니다 _和合團結_ 감사합니다_^))//