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