I find it interesting that the transform was controversial in the '90s.

Today, it seems like a normal solution to the problem to me, and the controversy seems silly. I have much experience with the map function from Javascript. It is too simple to be objectionable.

But in the '90s, I would also have had trouble understanding the transform. Lambdas/closures were unheard of to everyone except Lisp dweebs. Once I figured out what the code was doing, I would be suspicious of its performance and memory consumption. This was 1994! Kilobytes mattered and optimal algorithmic complexity was necessary for anything to be usable. Much safer to use a well understood for loop. I have plenty of experience making those fast, and that's what map() must be doing under the hood anyway.

But I would have been wrong! map() isn't doing anything superfluous and I can't do it faster myself. The memory consumption of the temporary decorated array is worth it to parse the last word N times instead of N log N times. Lisp is certainly a slow language compared to C, but that's not because of its lambdas!