Re: [Chicken-users] Review my Caesar Cipher?

[Alex Shinn]

On Tue, Mar 11, 2014 at 7:15 PM, Daniel Carrera <address@hidden> wrote:

With the last suggestion from Alex, and a tip to use cond-expand from Kon, I have settled on the following:

-----------------------------

;

; Works with Chicken Scheme and Gauche.

;

(cond-expand (chicken (use srfi-13))

             (gauche  (use srfi-13)))

 

(define msg "The quick brown fox jumps over the lazy dog.")

(define key 13)

 

(define (caesar char)

  (define A (char->integer #\A))

  (define Z (char->integer #\Z))

  (define a (char->integer #\a))

  (define z (char->integer #\z))

  (define c (char->integer char))

  (integer->char

    (cond ((<= A c Z) (+ A (modulo (+ key (- c A)) 26)))

          ((<= a c z) (+ a (modulo (+ key (- c a)) 26)))

          (else c)))) ; Return other characters verbatim.

 

(print (string-map caesar msg))

-----------------------------

I tried to include more Schemes, but Chibi doesn't seem to have SRFI-13

Chibi has string-map in (chibi string).

But actually, if you're aiming for R7RS support then

string-map is in (scheme base).  Just replace the

cond-expand with:

(import (scheme base))

-- 

Alex