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Michael Zhang 2020-12-04 19:01:41 -06:00
parent 70a8c18a27
commit ffb5f12540
Signed by: michael
GPG key ID: BDA47A31A3C8EE6B
1 changed files with 15 additions and 16 deletions
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31
4.hs
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@ -13,7 +13,7 @@ data Attr = Byr | Iyr | Eyr | Hgt | Hcl | Ecl | Pid | Cid
deriving (Show, Bounded, Enum, Eq, Ord) deriving (Show, Bounded, Enum, Eq, Ord)
intval :: Int -> Int -> Int -> Maybe Int intval :: Int -> Int -> Int -> Maybe Int
intval lo hi n = guard (n >= lo && n <= hi) $> n intval lo hi n = guard (lo <= n && n <= hi) $> n
nDigits :: Int -> String -> Maybe String nDigits :: Int -> String -> Maybe String
nDigits n s = guard (length s == n && all isDigit s) $> s nDigits n s = guard (length s == n && all isDigit s) $> s
@ -26,21 +26,20 @@ validEcl = flip elem ["amb", "blu", "brn", "gry", "grn", "hzl", "oth"]
parseAttr :: String -> Maybe Attr parseAttr :: String -> Maybe Attr
parseAttr s = parseAttr s =
let parts = splitOn ":" s in case splitOn ":" s of
let key = parts !! 0 in [key, value] -> case key of
let value = parts !! 1 in "byr" -> (readMaybe value >>= intval 1920 2002) $> Byr
case key of "iyr" -> (readMaybe value >>= intval 2010 2020) $> Iyr
"byr" -> (readMaybe value >>= intval 1920 2002) $> Byr "eyr" -> (readMaybe value >>= intval 2020 2030) $> Eyr
"iyr" -> (readMaybe value >>= intval 2010 2020) $> Iyr "hgt" ->
"eyr" -> (readMaybe value >>= intval 2020 2030) $> Eyr let inch = stripSuffix "cm" value >>= readMaybe >>= intval 150 193 in
"hgt" -> let cm = stripSuffix "in" value >>= readMaybe >>= intval 59 76 in
let inch = stripSuffix "cm" value >>= readMaybe >>= intval 150 193 in (inch <|> cm) $> Hgt
let cm = stripSuffix "in" value >>= readMaybe >>= intval 59 76 in "hcl" -> hexColor value $> Hcl
(inch <|> cm) $> Hgt "ecl" -> if validEcl value then Just Ecl else Nothing
"hcl" -> hexColor value $> Hcl "pid" -> nDigits 9 value $> Pid
"ecl" -> if validEcl value then Just Ecl else Nothing "cid" -> Just Cid
"pid" -> nDigits 9 value $> Pid _ -> Nothing
"cid" -> Just Cid
_ -> Nothing _ -> Nothing
processLine :: String -> Maybe [Attr] processLine :: String -> Maybe [Attr]