adventofcode1701/app/advent01.hs

   1 {-# LANGUAGE NegativeLiterals #-}
   2
   3 module Main(main) where
   4
   5 import Text.Parsec hiding (State)
   6 -- import Text.ParserCombinators.Parsec.Number
   7
   8
   9
  10 main :: IO ()
  11 main = do
  12         text <- readFile "data/advent01.txt"
  13         let instructions = successfulParse $ parseIline text
  14         part1 instructions
  15         part2 instructions
  16
  17 part1 :: [Int] -> IO ()
  18 part1 instructions = do
  19         print $ sum instructions
  20
  21 part2 :: [Int] -> IO ()
  22 part2 instructions = do
  23         print $ length $ takeWhile (>= 0) $ scanl (+) 0 instructions
  24
  25
  26
  27 -- instructionFile = instructionLine `endBy` newline
  28 instructionLine = many (up <|> down)
  29
  30
  31 up   = char '(' *> pure 1
  32 down = char ')' *> pure -1
  33
  34 -- parseIfile :: String -> Either ParseError [[Int]]
  35 -- parseIfile input = parse instructionFile "(unknown)" input
  36
  37 parseIline :: String -> Either ParseError [Int]
  38 parseIline input = parse instructionLine "(unknown)" input
  39
  40 successfulParse :: Either ParseError [a] -> [a]
  41 successfulParse (Left _) = []
  42 successfulParse (Right a) = a