Simplifications to add

Here are some of the simplifications I'd like to support.

If you'd like to work on some of these, please reply in a comment! If you want to suggest new ones, please open a new issue.

List

-- Possible but potentially quite ugly
List.foldl f x [ a ]
--> f (a) x

-- Only if acc is referenced only once
List.foldr (\a acc -> ... a :: acc) []
--> List.map (\a -> ... a)

List.drop n (List.drop m list)
--> List.drop (Basics.max 0 n + Basics.max 0 m) list -- Skip Basics.max if possible

List.take n (List.take m list)
--> List.take (Basics.max 0 (Basics.min n m)) list -- Skip Basics.min/max if possible

-- Only if n >= 1
list
  |> List.take n
  |> List.head
-->
list
  |> List.head

-- Possible but potentially quite ugly
list
  |> List.partition f
  |> Tuple.second
-->
list
  |> List.filter (f >> not) -- if we can insert a `not` in a nice way, that'd be cool!

list
  |> List.indexedMap Tuple.pair -- or equivalent lambda
  |> List.map Tuple.second
--> list

Set

-- Possible but potentially quite ugly
Set.foldl f x (Set.singleton a)
--> f a x

Maybe

-- ???
Maybe.andThen (f >> Maybe.map g) x
--> (Maybe.andThen (f) >> Maybe.map g) x