; phonebulb - turn phone numbers with embedded alpha characters into numbers

(define numbers
  '((#\a #\2) (#\b #\2) (#\c #\2) (#\A #\2) (#\B #\2) (#\C #\2)
    (#\d #\3) (#\e #\3) (#\f #\3) (#\D #\3) (#\E #\3) (#\F #\3)
    (#\g #\4) (#\h #\4) (#\i #\4) (#\G #\4) (#\H #\4) (#\I #\4)
    (#\j #\5) (#\k #\5) (#\l #\5) (#\J #\5) (#\K #\5) (#\L #\5)
    (#\m #\6) (#\n #\6) (#\o #\6) (#\M #\6) (#\N #\6) (#\O #\6)
    (#\p #\7) (#\q #\7) (#\r #\7) (#\s #\7) (#\P #\7) (#\Q #\7) (#\R #\7) (#\S #\7)
    (#\t #\8) (#\u #\8) (#\v #\8) (#\T #\8) (#\U #\8) (#\V #\8)
    (#\w #\9) (#\x #\9) (#\y #\9) (#\z #\9) (#\W #\9) (#\X #\9) (#\Y #\9) (#\Z #\9)))

(define (convert-loop)
   (display
    (list->string
     (map (lambda (char)
	    (let ((ch (assq char numbers)))
	      (if ch (cadr ch) char)))
	  (string->list (input-string "Broken Number?")))))
   (newline)
   (convert-loop))