51 lines
1.9 KiB
Scheme
51 lines
1.9 KiB
Scheme
;;; GNU Mes --- Maxwell Equations of Software
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;;; Copyright © 2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
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;;;
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;;; This file is part of GNU Mes.
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;;;
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;;; GNU 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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;;; GNU 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 GNU Mes. If not, see <http://www.gnu.org/licenses/>.
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(define display core:display)
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(define (newline) (core:display "\n"))
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(define (pair? x) (eq? (core:type x) <cell:pair>))
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(define (not x) (if x #f #t))
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(define-macro (cond . clauses)
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(list 'if (pair? clauses)
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(list (cons
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'lambda
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(cons
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'(test)
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(list (list 'if 'test
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(if (pair? (cdr (car clauses)))
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(if (eq? (car (cdr (car clauses))) '=>)
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(append2 (cdr (cdr (car clauses))) '(test))
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(list (cons 'lambda (cons '() (cons 'test (cdr (car clauses)))))))
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(list (cons 'lambda (cons '() (cons 'test (cdr (car clauses)))))))
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(if (pair? (cdr clauses))
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(cons 'cond (cdr clauses)))))))
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(car (car clauses)))))
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(define (f x)
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(display "x=") (display x) (newline)
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(cond ((not (pair? x)) 'dun)
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(#t
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((lambda (h t)
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(list h t))
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(f (car x))
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(f (cdr x))))))
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(display (f '(42)))
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(newline)
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