Advent of Code 2018, Day 1

Adv1.hs

-- I don't know if I'm gonna continue doing Advent of Code till the end, 
-- but I felt that I should share with the world, the horror that is this module's `main`
module Adv1 where

import qualified Data.IntSet    as S

partOne :: [Int] -> Int
partOne = sum 

partTwo :: [Int] -> Int
partTwo ls = goThrough (cycle ls) 0 S.empty
  where
    goThrough list frq frqs = if newFrq `S.member` frqs
      then newFrq
      else goThrough (tail list) newFrq (S.insert newFrq frqs)
        where
          newFrq = frq + (head list)

main = (loop []) >>= mconcat . (print <$>) . (<*>) [partOne, partTwo] . (: [])
  where
    loop listed = do
      line <- getLine
      if line == ""
        then pure listed
        else loop $ listed ++ [read' line]
    read' s = if head s == '+' then read $ tail s else read s