row-major-aref

(row-major-aref array index)

Returns the element of array at the given 0-based flat row-major index, independent of the array's rank -- element (i, j) of a 2x3 array is at flat index i * 3 + j. Use array-row-major-index to compute the flat index of a set of subscripts. To modify an element, use row-major-aref as a setf place: (setf (row-major-aref array k) value). Like aref, it is not exposed as a first-class function value, so call it directly. An index that is not an integer signals a type-error naming the operator (ROW-MAJOR-AREF: The value NIL is not of type INTEGER), reported as (SETF ROW-MAJOR-AREF) by the setf form.