[bpt/guile.git] / srfi / srfi-60.scm

;;; srfi-60.scm --- Integers as Bits

;; Copyright (C) 2005 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 2.1 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

(define-module (srfi srfi-60)
  #:export (bitwise-and
	    bitwise-ior
	    bitwise-xor
	    bitwise-not
	    any-bits-set?
	    bit-count
	    bitwise-if bitwise-merge
	    log2-binary-factors first-set-bit
	    bit-set?
	    copy-bit
	    bit-field
	    copy-bit-field
	    arithmetic-shift
	    rotate-bit-field
	    reverse-bit-field
	    integer->list
	    list->integer
	    booleans->integer)
  #:re-export (logand
	       logior
	       logxor
	       integer-length
	       logtest
	       logcount
	       logbit?
	       ash))

(load-extension "libguile-srfi-srfi-60-v-1" "scm_init_srfi_60")

(define bitwise-and logand)
(define bitwise-ior logior)
(define bitwise-xor logxor)
(define bitwise-not lognot)
(define any-bits-set? logtest)
(define bit-count logcount)

(define (bitwise-if mask n0 n1)
  (logior (logand mask n0)
          (logand (lognot mask) n1)))
(define bitwise-merge bitwise-if)

(define first-set-bit log2-binary-factors)
(define bit-set? logbit?)
(define bit-field bit-extract)

(define (copy-bit-field n newbits start end)
  (logxor n (ash (logxor (bit-extract n start end)              ;; cancel old
			 (bit-extract newbits 0 (- end start))) ;; insert new
		 start)))

(define arithmetic-shift ash)

(cond-expand-provide (current-module) '(srfi-60))
Commit	Line	Data
8884a084 KR	1	;;; srfi-60.scm --- Integers as Bits
	2
	3	;; Copyright (C) 2005 Free Software Foundation, Inc.
	4	;;
	5	;; This library is free software; you can redistribute it and/or
	6	;; modify it under the terms of the GNU Lesser General Public
	7	;; License as published by the Free Software Foundation; either
	8	;; version 2.1 of the License, or (at your option) any later version.
	9	;;
	10	;; This library is distributed in the hope that it will be useful,
	11	;; but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	;; Lesser General Public License for more details.
	14	;;
	15	;; You should have received a copy of the GNU Lesser General Public
	16	;; License along with this library; if not, write to the Free Software
92205699	17	;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
8884a084 KR	18
	19	(define-module (srfi srfi-60)
	20	#:export (bitwise-and
	21	bitwise-ior
	22	bitwise-xor
	23	bitwise-not
	24	any-bits-set?
	25	bit-count
	26	bitwise-if bitwise-merge
	27	log2-binary-factors first-set-bit
	28	bit-set?
	29	copy-bit
	30	bit-field
	31	copy-bit-field
	32	arithmetic-shift
	33	rotate-bit-field
	34	reverse-bit-field
	35	integer->list
	36	list->integer
	37	booleans->integer)
	38	#:re-export (logand
	39	logior
	40	logxor
	41	integer-length
	42	logtest
	43	logcount
	44	logbit?
	45	ash))
	46
	47	(load-extension "libguile-srfi-srfi-60-v-1" "scm_init_srfi_60")
	48
	49	(define bitwise-and logand)
	50	(define bitwise-ior logior)
	51	(define bitwise-xor logxor)
	52	(define bitwise-not lognot)
	53	(define any-bits-set? logtest)
	54	(define bit-count logcount)
	55
	56	(define (bitwise-if mask n0 n1)
	57	(logior (logand mask n0)
	58	(logand (lognot mask) n1)))
	59	(define bitwise-merge bitwise-if)
	60
	61	(define first-set-bit log2-binary-factors)
	62	(define bit-set? logbit?)
	63	(define bit-field bit-extract)
	64
	65	(define (copy-bit-field n newbits start end)
	66	(logxor n (ash (logxor (bit-extract n start end) ;; cancel old
	67	(bit-extract newbits 0 (- end start))) ;; insert new
	68	start)))
	69
	70	(define arithmetic-shift ash)
	71
	72	(cond-expand-provide (current-module) '(srfi-60))