Why there is no Seq.rev function? [closed]

Question

Looks like such a made up complication to me. In order to reverse a sequence (enumerable) one have to turn it to a list first. Why is that?

Answer 1

Since you can't walk through sequences backwards, lists are an ideal storage medium for reversing sequences. They even have the tendency of becoming reversed as you build them, go figure.

I have no idea why rev isn't in the Seq module in the first place, though. Even LINQ has a Reverse() operator. Fortunately, it is very easy to implement.

let rev xs = Seq.fold (fun acc x -> x::acc) [] xs

Another alternative is to just use LINQ's operator.

let rev = System.Linq.Enumerable.Reverse