elm/exercises/allergies/Allergies.example

module Allergies (..) where

import List
import Bitwise


isAllergicTo : String -> Int -> Bool
isAllergicTo name score =
  List.member name (toList score)


toList : Int -> List String
toList score =
  allergies
    |> List.indexedMap (\i n -> ( Bitwise.shiftLeft 1 i, n ))
    |> List.filter (\( s, n ) -> Bitwise.and s score > 0)
    |> List.map snd


allergies : List String
allergies =
  [ "eggs"
  , "peanuts"
  , "shellfish"
  , "strawberries"
  , "tomatoes"
  , "chocolate"
  , "pollen"
  , "cats"
  ]