(string-length string)
returns the number of characters in string.
> (string-length "Bevo") 4
(string->list string)
makes a list of the characters of string.
> (string->list "Bevo") (#\B #\e #\v #\o)
(list->string chars)
makes a string of the characters in the list chars.
> (list->string '(#\U #\T)) "UT"