[tvier]

Much of both sides of this argument are opinion, but wrt this comment.

> ... no function call overhead.

This code has more function calls. O(n) vs 3 for the original

[khaledh]

That's not true. The lambdas used in the functional version are each called once for every item in the list.

[stouset]

No sane optimizer is going to emit the functional code as a gajillion function calls.