**take** +containers

*O(log(min(i,n-i)))*. The first i elements of a sequence. If i is negative, take i s yields the empty sequence. If the sequence contains fewer than i elements, the whole sequence is returned.
*O(i)* applied to a predicate p and a sequence xs, returns the longest prefix (possibly empty) of xs of elements that satisfy p.

*O(i)* applied to a predicate p and a sequence xs, returns the longest suffix (possibly empty) of xs of elements that satisfy p.
takeWhileR p xs is equivalent to reverse (takeWhileL p (reverse xs)).