let dup: array('a) => array('a);
let sub: array('a) => int => int => array('a);
let concat: list(array('a)) => array('a);
let make: int => 'a => array('a);
let make_float: int => array(float);
let blit: array('a) => int => array('a) => int => int => unit;
let get: array('a) => int => 'a;
let set: array('a) => int => 'a => unit;