array-rank
array => rank
array--an array.
rank--a non-negative integer.
Returns the number of dimensions of array.
(array-rank (make-array '())) => 0 (array-rank (make-array 4)) => 1 (array-rank (make-array '(4))) => 1 (array-rank (make-array '(2 3))) => 2
Should signal an error of type type-error if its argument is not an array.