Question

How do i allocate a vector with 1042 empty indexes?
Will the storage for it be lazily allocated?
like this

(def a (array-creation-function 1042))
(def b (assoc a 1041 42))
(b 1041) 
--> 42

Answer 1

It seems that vectors are not sparse so you must specify a value for each index when you create the vector. The easiest way seems to be to call (vec ) on a sequence.

(vec (repeat 1042 nil))

These values are not created lazily it seems.