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| ;;; bitwise.scm --- The R6RS bitwise arithmetic operations library | |
| ;; Copyright (C) 2010, 2013 Free Software Foundation, Inc. | |
| ;; | |
| ;; This library is free software; you can redistribute it and/or | |
| ;; modify it under the terms of the GNU Lesser General Public | |
| ;; License as published by the Free Software Foundation; either | |
| ;; version 3 of the License, or (at your option) any later version. | |
| ;; | |
| ;; This library 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 | |
| ;; Lesser General Public License for more details. | |
| ;; | |
| ;; You should have received a copy of the GNU Lesser General Public | |
| ;; License along with this library; if not, write to the Free Software | |
| ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| (library (rnrs arithmetic bitwise (6)) | |
| (export bitwise-not | |
| bitwise-and | |
| bitwise-ior | |
| bitwise-xor | |
| bitwise-if | |
| bitwise-bit-count | |
| bitwise-length | |
| bitwise-first-bit-set | |
| bitwise-bit-set? | |
| bitwise-copy-bit | |
| bitwise-bit-field | |
| bitwise-copy-bit-field | |
| bitwise-arithmetic-shift | |
| bitwise-arithmetic-shift-left | |
| bitwise-arithmetic-shift-right | |
| bitwise-rotate-bit-field | |
| bitwise-reverse-bit-field) | |
| (import (rnrs base (6)) | |
| (rnrs control (6)) | |
| (rename (only (srfi srfi-60) bitwise-if | |
| integer-length | |
| first-set-bit | |
| copy-bit | |
| bit-field | |
| copy-bit-field | |
| rotate-bit-field | |
| reverse-bit-field) | |
| (integer-length bitwise-length) | |
| (first-set-bit bitwise-first-bit-set) | |
| (bit-field bitwise-bit-field) | |
| (reverse-bit-field bitwise-reverse-bit-field)) | |
| (rename (only (guile) lognot | |
| logand | |
| logior | |
| logxor | |
| logcount | |
| logbit? | |
| modulo | |
| ash) | |
| (lognot bitwise-not) | |
| (logand bitwise-and) | |
| (logior bitwise-ior) | |
| (logxor bitwise-xor) | |
| (ash bitwise-arithmetic-shift))) | |
| (define (bitwise-bit-count ei) | |
| (if (negative? ei) | |
| (bitwise-not (logcount ei)) | |
| (logcount ei))) | |
| (define (bitwise-bit-set? ei1 ei2) (logbit? ei2 ei1)) | |
| (define (bitwise-copy-bit ei1 ei2 ei3) | |
| ;; The specification states that ei3 should be either 0 or 1. | |
| ;; However, other values have been tolerated by both Guile 2.0.x and | |
| ;; the sample implementation given the R6RS library document, so for | |
| ;; backward compatibility we continue to permit it. | |
| (copy-bit ei2 ei1 (logbit? 0 ei3))) | |
| (define (bitwise-copy-bit-field ei1 ei2 ei3 ei4) | |
| (copy-bit-field ei1 ei4 ei2 ei3)) | |
| (define (bitwise-rotate-bit-field ei1 ei2 ei3 ei4) | |
| (rotate-bit-field ei1 ei4 ei2 ei3)) | |
| (define bitwise-arithmetic-shift-left bitwise-arithmetic-shift) | |
| (define (bitwise-arithmetic-shift-right ei1 ei2) | |
| (bitwise-arithmetic-shift ei1 (- ei2)))) | |