Add `bytevector->base16-string'.

* guix/utils.scm (bytevector->base16-string): New procedure.
This commit is contained in:
Ludovic Courtès 2012-06-01 23:29:55 +02:00
parent f9c7080aa3
commit 38b3122afb
1 changed files with 38 additions and 0 deletions

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@ -17,16 +17,25 @@
;;; along with Guix. If not, see <http://www.gnu.org/licenses/>. ;;; along with Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix utils) (define-module (guix utils)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-60) #:use-module (srfi srfi-60)
#:use-module (rnrs bytevectors) #:use-module (rnrs bytevectors)
#:use-module (ice-9 format)
#:use-module ((chop hash) #:use-module ((chop hash)
#:select (bytevector-hash #:select (bytevector-hash
hash-method/sha256)) hash-method/sha256))
#:export (bytevector-quintet-length #:export (bytevector-quintet-length
bytevector->base32-string bytevector->base32-string
bytevector->nix-base32-string bytevector->nix-base32-string
bytevector->base16-string
sha256)) sha256))
;;;
;;; Base 32.
;;;
(define bytevector-quintet-ref (define bytevector-quintet-ref
(let* ((ref bytevector-u8-ref) (let* ((ref bytevector-u8-ref)
(ref+ (lambda (bv offset) (ref+ (lambda (bv offset)
@ -151,6 +160,35 @@ the previous application or INIT."
(define bytevector->nix-base32-string (define bytevector->nix-base32-string
(make-bytevector->base32-string bytevector-quintet-fold-right (make-bytevector->base32-string bytevector-quintet-fold-right
%nix-base32-chars)) %nix-base32-chars))
;;;
;;; Base 16.
;;;
(define (bytevector->base16-string bv)
"Return the hexadecimal representation of BV's contents."
(define len
(bytevector-length bv))
(let-syntax ((base16-chars (lambda (s)
(syntax-case s ()
(_
(let ((v (list->vector
(unfold (cut > <> 255)
(lambda (n)
(format #f "~2,'0x" n))
1+
0))))
v))))))
(define chars base16-chars)
(let loop ((i 0)
(r '()))
(if (= i len)
(string-concatenate-reverse r)
(loop (+ 1 i)
(cons (vector-ref chars (bytevector-u8-ref bv i)) r))))))
;;; ;;;
;;; Hash. ;;; Hash.