/usr/share/gauche-0.9/0.9.4/lib/math/mt-random.scm is in gauche 0.9.4-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 | ;;;
;;; mt-random - Mersenne Twister interface
;;;
;;; 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.
;;;
(define-module math.mt-random
(use gauche.uvector)
(export <mersenne-twister>
mt-random-set-seed!
mt-random-get-state
mt-random-set-state!
mt-random-real
mt-random-real0
mt-random-integer
mt-random-fill-u32vector!
mt-random-fill-f32vector!
mt-random-fill-f64vector!)
)
(select-module math.mt-random)
(dynamic-load "math--mt-random")
(define (%get-nword-random-int mt n)
(let loop ([i 0] [r (%mt-random-uint32 mt)])
(if (= i n)
r
(loop (+ i 1)
(+ (ash r 32) (%mt-random-uint32 mt))))))
(define (mt-random-integer mt n)
(when (not (positive? n)) (error "invalid range" n))
(if (<= n #x100000000)
(%mt-random-integer mt n)
(let* ([siz (ash (integer-length n) -5)]
[q (quotient (ash 1 (* 32 (+ siz 1))) n)]
[qn (* q n)])
(let loop ([r (%get-nword-random-int mt siz)])
(if (< r qn)
(quotient r q)
(loop (%get-nword-random-int mt siz)))))))
|