Try day 4

AdventOfCode2020.cabal

@@ -17,7 +17,7 @@ maintainer:          gael@depreeuw.dev
 extra-source-files:  CHANGELOG.md, README.md
 
 library
-  exposed-modules:     Day1, Day2, Day3
+  exposed-modules:     Day1, Day2, Day3, Day4
   -- other-modules:
   -- other-extensions:
   build-depends:       base ^>=4.13.0.0

src/Day4.hs

@@ -0,0 +1,55 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Day4 (day4) where
+
+import Control.Applicative ((<|>))
+import Control.Monad (void)
+import qualified Data.Attoparsec.Text as P
+
+-- import qualified Data.Text as T
+-- import qualified Data.Vector as V
+-- import Numeric.Natural (Natural)
+
+type BYR = String
+
+type IYR = String
+
+type EYR = String
+
+type HGT = String
+
+type HCL = String
+
+type ECL = String
+
+type PID = String
+
+type CID = String
+
+data Passport = Passport
+  { byr :: BYR,
+    iyr :: IYR,
+    eyr :: EYR,
+    hgt :: HGT,
+    hcl :: HCL,
+    ecl :: ECL,
+    pid :: PID,
+    cid :: Maybe CID -- Definitely not a hack!
+  }
+  deriving (Eq, Show)
+
+parsePassport :: P.Parser Passport
+parsePassport = do
+  -- parse pairs
+  pairs <- parsePair `P.sepBy` (void P.space <|> P.endOfLine)
+  undefined
+
+parsePair :: P.Parser (String, String)
+parsePair = do
+  key <- P.count 3 P.letter
+  _ <- P.char ':'
+  value <- P.many1 P.anyChar
+  return (key, value)
+
+day4 :: IO ()
+day4 = putStrLn "Day 4"