On Mon, Mar 10, 2014 at 10:26:56AM -0500, Phil Bewig wrote: > I would use an auxiliary function char-plus to add or subtract an offset to > a character: > > (define (caesar str n) > (define (char-plus c) > (let ((alpha "ABCDEFGHIJKLMNOPQRSTUVWXYZ")) > (if (not (char-alphabetic? c)) c > (let ((i (- (char->integer (char-upcase c)) 65))) > (string-ref alpha (modulo (+ i n) 26)))))) > (list->string (map char-plus (string->list str))))
If you're using srfi-13, you might as well change the final line to use string-map: (string-map char-plus str) Cheers, Peter -- http://www.more-magic.net _______________________________________________ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
