mes/module/rnrs/bytevectors.mes
Jan Nieuwenhuizen 40593ac218 Bugfixes bytevectors.
* math.c (modulo): Modulo of negative value correctly.
* module/mes/bytevectors.mes (bytevector-u32-native-set!):
  (bytevector-u16-native-set!): Use ash instead of quotient.
2017-01-04 21:44:38 +01:00

50 lines
1.6 KiB
Scheme

;;; -*-scheme-*-
;;; Mes --- Maxwell Equations of Software
;;; Copyright © 2016,2017 Jan Nieuwenhuizen <janneke@gnu.org>
;;;
;;; 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/>.
;;; Commentary:
;;; bytevectors.mes
;;; Code:
;; rnrs compatibility
(define (bytevector-u32-native-set! bv index value)
(when (not (= 0 index)) (error "bytevector-u32-native-set! index not zero: " index " value: " value))
(let ((x (list
(modulo value #x100)
(modulo (ash value -8) #x100)
(modulo (ash value -16) #x100)
(modulo (ash value -24) #x100))))
(set-car! bv (car x))
(set-cdr! bv (cdr x))
x))
(define (bytevector-u16-native-set! bv index value)
(when (not (= 0 index)) (error "bytevector-u16-native-set! index not zero: " index " value: " value))
(let ((x (list
(modulo value #x100)
(modulo (ash value -8) #x100))))
(set-car! bv (car x))
(set-cdr! bv (cdr x))
x))
(define (make-bytevector length)
(make-list length 0))