| result-sequence | sequence type specifier or NIL |
| fn | function that takes as many arguments as there are sequences |
| seqs | sequences which elements are processed in parallel |
MAP-INTO applies function fn to elements of sequence with same index. Each application result is destructively put into resulting sequence. The iteration terminates when the shortest sequence (of any of the sequences or the result-sequence) is exhausted. Return value is same as the first argument. See also MAP, MAPCAR and MAPCAN.
(let ((a (list 1 2 3 4))) (map-into a #'* a a) a) => (1 4 9 16) (let ((a (vector 1 2 3 4))) (map-into a #'* a a) a) => #(1 4 9 16) (let ((a (vector 1 2 3 4))) (map-into a #'1+ '(1 2)) a) => #(2 3 3 4)