Shrink Strategy for Ints

shrinkInt.elm

shrinkInt : Int -> List Int
shrinkInt n =
  if n < 0 
  then
    -n :: List.map ((*) -1) (series 0 -n)
  else
    series 0 n
  
  
series : Int -> Int -> List Int
series low high = 
  if | low >= high -> []
     | low == high - 1 -> [low]
     | otherwise -> 
         let low' = low + ((high - low) // 2)
         in
           low :: series low' high