elm/exercises/hamming/Hamming.example

module Hamming exposing (..)

import String exposing (length, toList)


distance : String -> String -> Maybe Int
distance left right =
  if length left /= length right then
    Nothing
  else
    List.map2 (\l r -> l /= r) (toList left) (toList right)
      |> List.filter identity
      |> List.length
      |> Just