S9 LIB  (string-reverse string)   ==>  string
        (string-reverse! string)  ==>  unspecific

Create a fresh string and fill it with the characters of
STRING, but in reverse order. STRING-REVERSE! reverses the
characters of STRING in situ, overwriting the original
string.

(string-reverse "rats live on no evil star")
            ==> "rats live on no evil star"
