List.pairwise in Elm

List.elm

module Common.List exposing (pairwise)

import List exposing (drop, head, length, take)
import List.Extra exposing (zip)
import Maybe.Extra exposing (toList)


pairwise : List a -> List ( a, a )
pairwise lst =
    let
        grp =
            take 2 lst

        tup =
            zip (take 1 grp) (drop 1 grp)
                |> head
                |> toList

        remaining =
            drop 1 lst
    in
    if 2 == length grp then
        List.append tup (pairwise remaining)
    else
        []

This should be equivalent:

import List.Extra

pairwise : List a -> List ( a, a )
pairwise lst =
  lst  |> List.Extra.groupsOf 2 
        |> case l of 
              a :: b :: _ -> (a,b)
               _ -> (0,0)