This is a port of the Python code from the "Complete Roguelike Tutorial, using python+libtcod" into Common Lisp using cl-tcod (the official version needs to be updated though, see below). It uses ...

;(check-expect (encrypt-one-letter "Z" 1) "A") ;Throws an error, "A" is expected, returned "[" ;The above code works, however, if we try to change "Z", it does not go to "A" like we want. This is ...