Solve day 4, part 1

src/Day4.hs

@@ -25,7 +25,7 @@ type PID = T.Text
 
 type CID = T.Text
 
-data Passport = Passport
+data Passport = ValidPassport
   { byr :: BYR,
     iyr :: IYR,
     eyr :: EYR,
@@ -56,7 +56,7 @@ fromMap m = do
   hcl <- m M.!? "hcl"
   ecl <- m M.!? "ecl"
   pid <- m M.!? "pid"
-  return $ Passport byr iyr eyr hgt hcl ecl pid (m M.!? "cid")
+  return $ ValidPassport byr iyr eyr hgt hcl ecl pid (m M.!? "cid")
 
 parserPassport :: P.Parser (Maybe Passport)
 parserPassport = fromMap <$> parserEntry