diff --git a/osc.lisp b/osc.lisp index cdce438..9749422 100644 --- a/osc.lisp +++ b/osc.lisp @@ -309,37 +309,23 @@ (elt s 3)))) i)) -(defun encode-int32 (i) - "convert an integer into a sequence of 4 bytes in network byte order." - (declare (type integer i)) - (let ((buf (make-sequence - '(vector (unsigned-byte 8)) 4))) - (macrolet ((set-byte (n) - `(setf (elt buf ,n) - (logand #xff (ash i ,(* 8 (- n 3))))))) - (set-byte 0) - (set-byte 1) - (set-byte 2) - (set-byte 3)) - buf)) +(defmacro defint-encoder (num-of-octets &optional docstring) + (let ((enc-name (intern (format nil "~:@(encode-int~)~D" (* 8 num-of-octets)))) + (buf (gensym)) + (int (gensym))) + `(defun ,enc-name (,int) + ,@(when docstring + (list docstring)) + (let ((,buf (make-array ,num-of-octets :element-type '(unsigned-byte 8)))) + ,@(loop + for n below num-of-octets + collect `(setf (aref ,buf ,n) + (ldb (byte 8 (* 8 (- (1- ,num-of-octets) ,n))) + ,int))) + ,buf)))) -(defun encode-int64 (i) - "convert an integer into a sequence of 8 bytes in network byte order." - (declare (type integer i)) - (let ((buf (make-sequence - '(vector (unsigned-byte 8)) 8))) - (macrolet ((set-byte (n) - `(setf (elt buf ,n) - (logand #xff (ash i ,(* 8 (- n 7))))))) - (set-byte 0) - (set-byte 1) - (set-byte 2) - (set-byte 3) - (set-byte 4) - (set-byte 5) - (set-byte 6) - (set-byte 7)) - buf)) +(defint-encoder 4 "Convert an integer into a sequence of 4 bytes in network byte order.") +(defint-encoder 8 "Convert an integer into a sequence of 8 bytes in network byte order.") (defun decode-uint64 (s) "8 byte -> 64 bit unsigned int"