(display "Please, enter the string in lower case bounded by \" sign: ")
(lfor
   (list->ff '(
     (#\a . ".-"   ) (#\b . "-..." ) (#\c . "-.-." )
     (#\d . "-.."  ) (#\e . "."    ) (#\f . "..-." )
     (#\g . "--."  ) (#\h . "...." ) (#\i . ".."   )
     (#\j . ".---" ) (#\k . "-.-"  ) (#\l . ".-.." )
     (#\m . "--"   ) (#\n . "-."   ) (#\o . "---"  )
     (#\p . ".--." ) (#\q . "--.-" ) (#\r . ".-."  )
     (#\s . "..."  ) (#\t . "-"    ) (#\u . "..-"  )
     (#\v . "...-" ) (#\w . ".--"  ) (#\x . "-..-" )
     (#\y . "-.--" ) (#\z . "--.." ) (#\1 . ".----")
     (#\2 . "..---") (#\3 . "...--") (#\4 . "....-")
     (#\5 . ".....") (#\6 . "-....") (#\7 . "--...")
     (#\8 . "---..") (#\9 . "----.") (#\0 . "-----")
     (#\space . " ") (#\. . "  ")))
  (str-iter (read))
  (lambda (codes char)
     (let ((out (getf codes char)))
        (if out (display out)))
     codes))

; ==> Please, enter the string in lower case bounded by " sign:
; <== "hello world"
; ==> ......-...-..--- .-----.-..-..-..