Because my cow-orkers just had to bring up the Dreaded Site™, and I just had to look at the Scheme version and note that, while at least it was present, the organization of the code in all three versions left a great deal to be desired. A few more moments of reading revealed that the output was wrong, too.
I'm sure you can see where this is going.
;; Gnomon - on Thu Apr 17 23:54:52 EDT 2008 ;; sha1sum of lastname, firstname, newline: ;; 3952893c66ffbe071f266caa04b25161c1da30a1 ;; Because I wanted a version that would Do ;; The Right Thing with capitals and plural ;; cases, and because mixing logic, display ;; and generation code does not satisfy me. (define (iota n) (let loop ((l '()) (i 0)) (if (> i n) l (loop (cons i l) (+ i 1))))) ;; See SRFI-1 for a better version of this; ;; my function is backward in several ways. ;; It can also be argued that SRFI-42 could ;; allow an implementation that consed up a ;; bit less temporary garbage. If SRFI-1 is ;; out, though, SRFI-42 is way out. Basics. (define (plural? n . up) (let ((.. string-append) (num (number->string n)) (bot " bottle") (ltr (if (null? up) "n" "N"))) (case n ((0) (.. ltr "o more" bot "s")) ((1) (.. num bot)) (else (.. num bot "s"))))) ;; PLURAL? has to merge the logic for cases ;; when the string will be used at the head ;; of a sentence, requiring a capital; when ;; only one bottle is left, which needs the ;; singular form; and when none are left at ;; all, which requires a special case. It's ;; lucky that not all combinations of these ;; cases can be reached, allowing us to use ;; only three of the possible six branches. (define (verse n) (let ((.. string-append) (top (plural? n 1)) (mid (plural? n)) (nxt (plural? (if (= n 0) 99 (- n 1)))) (beer " of beer") (wall " on the wall") (actn (if (= n 0) "Go to the store and buy some more, " "Take one down and pass it around, "))) `(,(.. top beer wall ", " mid beer ".") . ,(.. actn nxt beer wall ".")))) ;; VERSE conses a pair where the CAR stores ;; the first line of the verse, and the CDR ;; the second. There is no sense in using a ;; proper list; we would just waste the end ;; of it anyways. Also: yay quasiquotation! (define (sing verse) (let ((n newline)) (display (car verse)) (n) (display (cdr verse)) (n) (n))) ;; SING exploits the implicit BEGIN wrapped ;; around the body of a LET to DISPLAY both ;; lines of a verse in order. Also note the ;; pleasant symmetry of CAR and CDR that we ;; get to use because of our choice made up ;; above in VERSE to use a dotted pair as a ;; representation instead of a proper list. (for-each sing (map verse (iota 99))) ;; MAP for effect, FOR-EACH for side effect
It's been submitted for inclusion, of course, with the following lines as an additional note to the site maintainers:
;; The code is long, the comments too; ;; A bit less wrong than version two; ;; No syntax-case, like version three; ;; Just one right place per step, you see.