Just FYI: Recent REBOL's include the ability to perform
bitwise operations on binary types using AND, OR, and
XOR. -jeff
-------------------------------------------------------
nibble: func [
a [binary!] "Binary Byte"
b [integer!] "0-15" /high
][a or to-binary to-char either high [b * 16][b]]
comment [
nibble/high #{01} 15 == #{F1}
nibble #{10} 15 == #{1F}
]
> >In Assembler class we called a *niblet*
> >the lower- or higher- order 4 bits in
> >a byte. I'd like a function that would
> >would write a niblet in a char! type.
> >It would something like this:
> >
> > >>niblet/low #"a" 2 ; write 0010 to low-order "niblet"
> >==#"b" ; changed low-order "niblet" = 2
> > >>niblet/high #"b" 7 ; write 0111 to high-order "niblet"
> >== #"r" ; r is ascii 72
>
> Well, this function is kinda ugly and could probably be
> done MUCH better, but it works:
>
> niblet: func [ base new /low /high ] [
> either high [
> or~ (and~ base to-char 15)
> to-char (16 * to-integer and~ new to-char 15)
> ][ or~ (and~ base to-char 240) (and~ new to-char 15)
> ]
> ]
>
> I've been meaning to write decent functions for doing
> binary manipulations in REBOL but I haven't had time yet,
> but when I do I'll post them on rebol.org (and maybe to the
> list)
>
> Hope this helps,
>
> Cal Dixon ([EMAIL PROTECTED]) -><-
>
> >This is for a high-school course that I'm designing as an
> >intro to programming using rebol.
> >
> >Thanks: -Tim
