Closed ekaitz-zarraga closed 6 months ago
This commit should reduce the amount of iterations in concatenate to N where N is the sum of the lengths of the input lists.
The previous implementation iterated from the beginning in each concatenation because of last-pair.
last-pair
This implementation is significantly faster in this extreme case:
(concatenate! `(,(iota 50000) ,@(map list (iota 500))))
Previous implementation: real 0m0.671s user 0m0.658s sys 0m0.013s
This implementation: real 0m0.175s user 0m0.174s sys 0m0.001s
The tests is done using time, which is not reliable at all, but using (trace last-pair) shows accurately what happens with the iterations.
time
(trace last-pair)
This commit should reduce the amount of iterations in concatenate to N where N is the sum of the lengths of the input lists.
The previous implementation iterated from the beginning in each concatenation because of
last-pair.This implementation is significantly faster in this extreme case:
Previous implementation: real 0m0.671s user 0m0.658s sys 0m0.013s
This implementation: real 0m0.175s user 0m0.174s sys 0m0.001s
The tests is done using
time, which is not reliable at all, but using(trace last-pair)shows accurately what happens with the iterations.