**Packages**- base
- bytestring
- text

foldr, applied to a binary operator, a starting value (typically the right-identity of the operator), and a list, reduces the list using the binary operator, from right to left:
> foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)

Fold over the elements of a structure, associating to the right, but strictly.

flip f takes its (first) two arguments in the reverse order of f.

Consume the chunks of a lazy ByteString with a natural right fold.

Consume the chunks of a lazy Text with a natural right fold.

zipWith generalises zip by zipping with the function given as the first argument, instead of a tupling function. For example, zipWith (+) is applied to two lists to produce the list of corresponding sums.

The non-overloaded version of insert.

Consume the chunks of a lazy ByteString with a strict, tail-recursive, accumulating left fold.

Consume the chunks of a lazy Text with a strict, tail-recursive, accumulating left fold.

Lift a binary function to actions.

The deleteFirstsBy function takes a predicate and two lists and returns the first list with the first occurrence of each element of the second list removed.

The intersectBy function is the non-overloaded version of intersect.

Fold over the elements of a structure, associating to the left, but strictly.

foldl, applied to a binary operator, a starting value (typically the left-identity of the operator), and a list, reduces the list using the binary operator, from left to right:
> foldl f z [x1, x2, ..., xn] == (...((z `f` x1) `f` x2) `f`...) `f` xn
The list must be finite.