/usr/share/gauche-0.9/0.9.4/lib/gauche/logical.scm is in gauche 0.9.4-6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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;;; logical.scm - logical (bitwise) operations. to be autoloaded.
;;;
;;; Copyright (c) 2000-2014 Shiro Kawai <shiro@acm.org>
;;;
;;; Redistribution and use in source and binary forms, with or without
;;; modification, are permitted provided that the following conditions
;;; are met:
;;;
;;; 1. Redistributions of source code must retain the above copyright
;;; notice, this list of conditions and the following disclaimer.
;;;
;;; 2. Redistributions in binary form must reproduce the above copyright
;;; notice, this list of conditions and the following disclaimer in the
;;; documentation and/or other materials provided with the distribution.
;;;
;;; 3. Neither the name of the authors nor the names of its contributors
;;; may be used to endorse or promote products derived from this
;;; software without specific prior written permission.
;;;
;;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
;;; "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
;;; LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
;;; A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
;;; OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
;;; SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
;;; TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
;;; PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
;;; LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
;;; NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
;;; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;;;
(select-module gauche)
;; SLIB compatible interface.
(define (logtest . args) ;; can be optimized for two-arg case
(not (zero? (apply logand args))))
(define (logbit? index n)
(not (zero? (logand n (ash 1 index)))))
(define (copy-bit index from bit)
(if bit
(logior (ash 1 index) from)
(logand (lognot (ash 1 index)) from)))
(define (bit-field n start end)
(check-arg integer? start)
(check-arg integer? end)
(if (< start end)
(let1 mask (- (ash 1 (- end start)) 1)
(logand (ash n (- start)) mask))
0))
(define (copy-bit-field to from start end)
(check-arg integer? start)
(check-arg integer? end)
(if (< start end)
(let1 mask (- (ash 1 (- end start)) 1)
(logior (logand to (lognot (ash mask start)))
(ash (logand from mask) start)))
from))
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