You can use positive exact integers with bitwise operations. Look for the word 'bitwise' in the docs. Use (number->string n 2) for display of the bitstring n. You may have to add leading zero's when you want a specific number of bits to be shown. Jos
> -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Michael Coppola > Sent: 24 January 2011 08:59 > To: [email protected] > Subject: [racket] Handling bits > > Hola Racketeers, > > I'm writing a program that performs a lot of binary math, and I was > wondering if there were any established ways in the Racket language to > handle bits or just C-style binary arithmetic in general. > For instance, > the C language lets you store any arbitrary byte to a buffer > and perform > whatever you want to it (like bitwise math), but data types in Racket > are so sharply defined that I'm having trouble doing what I > need to in a > straightforward manner. Right now, my solution is to keep a string of > bits (literal 1s and 0s in a string) and write functions to recure > through it (by means of substring and string-append), but > this is a very > not-so-great solution. I've been calling these "bit strings" > throughout > my program. > > Here's an example of one of my functions: > > ;; bw-and : String String -> String > ;; Performs a bitwise AND on two bit strings. Both strings must be of > the same length. > (define (bw-and str1 str2) > (cond [(string=? str1 "") ""] > [else (string-append > (number->string > (bitwise-and (string->number (substring str1 0 1)) > (string->number (substring str2 0 1)))) > (bw-and (substring str1 1) (substring str2 1)))])) > > ...and would be called like: > > > (bw-and "11110000" "00110011") > "00110000" > > > > Again, not very elegant. Plus, I have to write functions to actually > convert back and forth between ASCII strings (normal text) and bit > strings. Are there any specific data types or just more suitable ways > of storing and handling bit strings? Thank you in advance, good sirs > and madams > > Regards, > Michael Coppola > _________________________________________________ > For list-related administrative tasks: > http://lists.racket-lang.org/listinfo/users _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
