;;; basic-conversions.scm


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Really Fundamental Datatypes ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define card8->number   uint8->number)
(define card16->number  uint16->number)
(define card32->number  uint32->number)

(define int8->number    sint8->number)
(define int16->number   sint16->number)
(define int32->number   sint32->number)

(define number->card8   number->uint8)
(define number->card16  number->uint16)
(define number->card32  number->uint32)

(define number->card8/fill!  number->uint8/fill!)
(define number->card16/fill! number->uint16/fill!)
(define number->card32/fill! number->uint32/fill!)

(define number->int8    number->sint8)
(define number->int16   number->sint16)
(define number->int32   number->sint32)

(define number->int8/fill!  number->sint8/fill!)
(define number->int16/fill! number->sint16/fill!)
(define number->int32/fill! number->sint32/fill!)

(define string8->string  identity)
(define string->string8  identity)


;;; pad each character in a scheme string with a null
;;; so we end up with two bytes per character.

(define string->string16
  (lambda (str)
    (let* ((str-len (string-length str))
	   (new-str (make-string (* 2 str-len) null-char)))
      (do ((str-i 0 (+ str-i 1))
	   (new-i 1 (+ new-i 2)))
	  ((>= str-i str-len) new-str)
	(string-set! new-str new-i (string-ref str str-i))
	))))


;;; Each character is two bytes.  Remove the first from every character.

(define string16->string
  (lambda (str)
    (let* ((len (string-length str))
	   (new-len (quotient len 2))
	   (new (make-string new-len)))
      (do ((str-i 1 (+ str-i 2))
	   (new-i 0 (+ new-i 1)))
	  ((>= new-i new-len) new)
	(string-set! new new-i (string-ref str str-i))
	))))