mes/base0-if.mes
Jan Nieuwenhuizen bd2b81755a Remove evcon (Sorry John).
* mes.c (evcon): Remove, remove callers.
* base0-if.mes (cond): Rename from disabled-cond.
2016-10-15 11:56:18 +02:00

41 lines
1.6 KiB
Scheme

;;; -*-scheme-*-
;;; Mes --- Maxwell Equations of Software
;;; Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
;;;
;;; base.mes: This file is part of Mes.
;;;
;;; Mes is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; Mes is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with Mes. If not, see <http://www.gnu.org/licenses/>.
(define (cons* x . rest)
(define (loop rest)
(if (null? (cdr rest)) (car rest)
(cons (car rest) (loop (cdr rest)))))
(loop (cons x rest)))
(define-macro cond
(lambda clauses
(if (null? clauses) *unspecified*
(if (null? (cdr clauses))
(list 'if (car (car clauses))
(cons* 'begin (car (car clauses)) (cdr (car clauses)))
*unspecified*)
(if (eq? (car (cadr clauses)) 'else)
(list 'if (car (car clauses))
(cons* 'begin (car (car clauses)) (cdr (car clauses)))
(cons* 'begin *unspecified* (cdr (cadr clauses))))
(list 'if (car (car clauses))
(cons* 'begin (car (car clauses)) (cdr (car clauses)))
(cons* 'cond (cdr clauses))))))))