elm/exercises/sublist/Sublist.example

module Sublist (..) where

import List exposing (..)
import String


sublist : List a -> List a -> String
sublist alist blist =
  if alist == blist then
    "Equal"
  else if inList alist blist then
    "Superlist"
  else if inList blist alist then
    "Sublist"
  else
    "Unequal"


inList : List a -> List a -> Bool
inList alist blist =
  let
    getLastInList sublist =
      case (List.tail sublist) of
        Just list ->
          list

        Nothing ->
          []
  in
    if (List.length alist) < (List.length blist) then
      False
    else if (List.take (List.length blist) alist) == blist then
      True
    else
      inList (getLastInList alist) blist