(aset-char array idx val) (aset-char array idx idx2 & idxv)
Sets the value at the index/indices. Works on arrays of char. Returns val.
;; create an array of 10 characters (initially set to blank by default)
;; and set one of the elements to the character "a"
user=> (def cs (char-array 10))
#'user/cs
user=> (vec cs)
[\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ ]
user=> (aset-char cs 3 \\a)
\\a
user=> (vec cs)
[\\ \\ \\ \\a \\ \\ \\ \\ \\ \\ ]
user=>