Advent of Code 2017 day 1

day1.exs

digits = inp 
  |> String.codepoints()
  |> (fn [hd | tl] -> [hd | tl] ++ [hd] end).() 
  |> Enum.map(&String.to_integer/1)
  |> Enum.chunk_every(2, 1, :discard)
  |> Enum.filter(fn [a, b] -> a == b end)
  |> Enum.map(&List.first/1)
  |> Enum.sum
  |> IO.inspect()

digits = inp
  |> String.codepoints()
  |> Stream.map(&String.to_integer/1)

half = digits
  |> Enum.count()
  |> Kernel./(2)

{first, second} = Enum.split(digits, half)

first
  |> Enum.zip(second)
  |> Enum.filter(fn {a, b} -> a == b end)
  |> Enum.map(&Tuple.to_list/1)
  |> Enum.map(&List.first/1)
  |> Enum.sum()
  |> Kernel.*(2)
  |> IO.inspect()