code.delx.au - gnu-emacs-elpa/blob - packages/test-simple/example/gcd.el

   1 ;;; test-simple.el --- Simple Unit Test Framework for Emacs Lisp
   2 ;; Copyright (C) 2015 Free Software Foundation, Inc
   3
   4 ;; Author: Rocky Bernstein <rocky@gnu.org>
   5 ;; URL: http://github.com/rocky/emacs-test-simple
   6 ;; Keywords: unit-test
   7 ;; Version: 1.0
   8
   9 ;; This program is free software: you can redistribute it and/or
  10 ;; modify it under the terms of the GNU General Public License as
  11 ;; published by the Free Software Foundation, either version 3 of the
  12 ;; License, or (at your option) any later version.
  13
  14 ;; This program is distributed in the hope that it will be useful, but
  15 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 ;; General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with this program.  If not, see
  21 ;; <http://www.gnu.org/licenses/>.
  22 (defun gcd(a b)
  23   "Greatest Common Divisor of A and B"
  24   ;; Make a < b
  25   (if (> a b)
  26       (let ((c a))
  27         (setq a b)
  28         (setq b c)))
  29   (cond
  30    ((< a 0) nil)
  31    ((or (= 0 (- b a)) (= a 1)) a)
  32    (t (gcd (- b a) a))
  33    )
  34 )