Hell's API

Version: 2025-06-09

Back to homepage

Types

• data () :: *
• data Bool :: *
• data ByteString :: *
• data Char :: *
• data Day :: *
• data Double :: *
• data Either :: * -> * -> *
• data ExitCode :: *
• data Handle :: *
• data IO :: * -> *
• data Int :: *
• data Integer :: *
• data Map :: * -> * -> *
• data Maybe :: * -> *
• data Set :: * -> *
• data Text :: *
• data These :: * -> * -> *
• data TimeOfDay :: *
• data Tree :: * -> *
• data UTCTime :: *
• data Value :: *
• data Vector :: * -> *

Terms

$

• $ :: forall a b . (a -> b) -> a -> b

• . :: forall a b c . (b -> c) -> (a -> b) -> a -> c

<$>

• <$> :: forall f a b . Functor f => (a -> b) -> f a -> f b

<**>

• <**> :: forall f a b . Applicative f => f a -> f (a -> b) -> f b

<*>

• <*> :: forall f a b . Applicative f => f (a -> b) -> f a -> f b

<>

• <> :: forall m . Semigroup m => m -> m -> m

Alternative

• Alternative.optional :: forall f a . Alternative f => f a -> f (Maybe a)

Applicative

• Applicative.pure :: forall f a . Applicative f => a -> f a

Argument

• Argument.help :: forall a . Text -> Mod ArgumentFields a
• Argument.metavar :: forall a . Text -> Mod ArgumentFields a
• Argument.value :: forall a . a -> Mod ArgumentFields a

Async

• Async.concurrently :: forall a b . IO a -> IO b -> IO (a, b)
• Async.pooledForConcurrently :: forall a b . [a] -> (a -> IO b) -> IO [b]
• Async.pooledForConcurrently_ :: forall a . [a] -> (a -> IO ()) -> IO ()
• Async.pooledMapConcurrently :: forall a b . (a -> IO b) -> [a] -> IO [b]
• Async.pooledMapConcurrently_ :: forall a . (a -> IO ()) -> [a] -> IO ()
• Async.race :: forall a b . IO a -> IO b -> IO (Either a b)

Bool

• Bool.False :: Bool
• Bool.True :: Bool
• Bool.bool :: forall a . a -> a -> Bool -> a
• Bool.not :: Bool -> Bool

ByteString

• ByteString.getContents :: IO ByteString
• ByteString.hGet :: Handle -> Int -> IO ByteString
• ByteString.hPutStr :: Handle -> ByteString -> IO ()
• ByteString.interact :: (ByteString -> ByteString) -> IO ()
• ByteString.readFile :: Text -> IO ByteString
• ByteString.readProcess :: ProcessConfig () () () -> IO (ExitCode,ByteString,ByteString)
• ByteString.readProcessStdout_ :: ProcessConfig () () () -> IO ByteString
• ByteString.readProcess_ :: ProcessConfig () () () -> IO (ByteString,ByteString)
• ByteString.writeFile :: Text -> ByteString -> IO ()

Concurrent

• Concurrent.threadDelay :: Int -> IO ()

Day

• Day.addDays :: Integer -> Day -> Day
• Day.diffDays :: Day -> Day -> Integer
• Day.fromGregorianValid :: Integer -> Int -> Int -> Maybe Day
• Day.iso8601ParseM :: Text -> Maybe Day
• Day.iso8601Show :: Day -> Text

Directory

• Directory.copyFile :: Text -> Text -> IO ()
• Directory.createDirectory :: Text -> IO ()
• Directory.createDirectoryIfMissing :: Bool -> Text -> IO ()
• Directory.doesDirectoryExist :: Text -> IO Bool
• Directory.doesFileExist :: Text -> IO Bool
• Directory.getCurrentDirectory :: IO Text
• Directory.listDirectory :: Text -> IO [Text]
• Directory.removeFile :: Text -> IO ()
• Directory.renameFile :: Text -> Text -> IO ()
• Directory.setCurrentDirectory :: Text -> IO ()

Double

• Double.eq :: Double -> Double -> Bool
• Double.fromInt :: Int -> Double
• Double.mult :: Double -> Double -> Double
• Double.plus :: Double -> Double -> Double
• Double.readMaybe :: Text -> Maybe Double
• Double.show :: Double -> Text
• Double.showEFloat :: Maybe Int -> Double -> Text -> Text
• Double.showFFloat :: Maybe Int -> Double -> Text -> Text
• Double.subtract :: Double -> Double -> Double

Either

• Either.Left :: forall a b . a -> Either a b
• Either.Right :: forall a b . b -> Either a b
• Either.either :: forall a b x . (a -> x) -> (b -> x) -> Either a b -> x

Environment

• Environment.getArgs :: IO [Text]
• Environment.getEnv :: Text -> IO Text
• Environment.getEnvironment :: IO [(Text,Text)]

Eq

• Eq.eq :: forall a . Eq a => a -> a -> Bool

Error

• Error.error :: forall a . Text -> a

Exit

• Exit.ExitFailure :: Int -> ExitCode
• Exit.ExitSuccess :: ExitCode
• Exit.die :: forall a . Text -> IO a
• Exit.exitCode :: forall a . a -> (Int -> a) -> ExitCode -> a
• Exit.exitWith :: forall a . ExitCode -> IO a

Flag

• Flag.help :: forall a . Text -> Mod FlagFields a
• Flag.long :: forall a . Text -> Mod FlagFields a

Function

• Function.fix :: forall a . (a -> a) -> a
• Function.id :: forall a . a -> a

Functor

• Functor.fmap :: forall f a b . Functor f => (a -> b) -> f a -> f b

IO

• IO.AppendMode :: IOMode
• IO.BlockBuffering :: Maybe Int -> BufferMode
• IO.LineBuffering :: BufferMode
• IO.NoBuffering :: BufferMode
• IO.ReadMode :: IOMode
• IO.ReadWriteMode :: IOMode
• IO.WriteMode :: IOMode
• IO.forM_ :: forall a . [a] -> (a -> IO ()) -> IO ()
• IO.hClose :: Handle -> IO ()
• IO.hSetBuffering :: Handle -> BufferMode -> IO ()
• IO.mapM_ :: forall a . (a -> IO ()) -> [a] -> IO ()
• IO.openFile :: Text -> IOMode -> IO Handle
• IO.print :: forall a . Show a => a -> IO ()
• IO.pure :: forall a . a -> IO a
• IO.stderr :: Handle
• IO.stdin :: Handle
• IO.stdout :: Handle

Int

• Int.eq :: Int -> Int -> Bool
• Int.fromInteger :: Integer -> Int
• Int.mult :: Int -> Int -> Int
• Int.plus :: Int -> Int -> Int
• Int.readMaybe :: Text -> Maybe Int
• Int.show :: Int -> Text
• Int.subtract :: Int -> Int -> Int
• Int.toInteger :: Int -> Integer

Integer

• Integer.mult :: Integer -> Integer -> Integer
• Integer.plus :: Integer -> Integer -> Integer
• Integer.readMaybe :: Text -> Maybe Integer
• Integer.subtract :: Integer -> Integer -> Integer

Json

• Json.Array :: Vector Value -> Value
• Json.Bool :: Bool -> Value
• Json.Null :: Value
• Json.Number :: Double -> Value
• Json.Object :: Map Text Value -> Value
• Json.String :: Text -> Value
• Json.decode :: ByteString -> Maybe Value
• Json.encode :: Value -> ByteString
• Json.value :: forall a . a -> (Bool -> a) -> (Text -> a) -> (Double -> a) -> (Vector Value -> a) -> (Map Text Value -> a) -> Value -> a

List

• List.all :: forall a . (a -> Bool) -> [a] -> Bool
• List.and :: [Bool] -> Bool
• List.any :: forall a . (a -> Bool) -> [a] -> Bool
• List.break :: forall a . (a -> Bool) -> [a] -> ([a], [a])
• List.concat :: forall a . [[a]] -> [a]
• List.concatMap :: forall a b . (a -> [b]) -> [a] -> [b]
• List.cons :: forall a . a -> [a] -> [a]
• List.cycle :: forall a . [a] -> [a]
• List.deleteBy :: forall a . (a -> a -> Bool) -> a -> [a] -> [a]
• List.drop :: forall a . Int -> [a] -> [a]
• List.dropWhile :: forall a . (a -> Bool) -> [a] -> [a]
• List.dropWhileEnd :: forall a . (a -> Bool) -> [a] -> [a]
• List.elem :: forall a . Eq a => a -> [a] -> Bool
• List.elemIndex :: forall a . Eq a => a -> [a] -> Maybe Int
• List.elemIndices :: forall a . Eq a => a -> [a] -> [Int]
• List.filter :: forall a . (a -> Bool) -> [a] -> [a]
• List.find :: forall a . (a -> Bool) -> [a] -> Maybe a
• List.findIndex :: forall a . (a -> Bool) -> [a] -> Maybe Int
• List.findIndices :: forall a . (a -> Bool) -> [a] -> [Int]
• List.foldl' :: forall a b . (b -> a -> b) -> b -> [a] -> b
• List.foldr :: forall a b . (a -> b -> b) -> b -> [a] -> b
• List.group :: forall a . Eq a => [a] -> [[a]]
• List.groupBy :: forall a . (a -> a -> Bool) -> [a] -> [[a]]
• List.inits :: forall a . [a] -> [[a]]
• List.intercalate :: forall a . [a] -> [[a]] -> [a]
• List.intersperse :: forall a . a -> [a] -> [a]
• List.isInfixOf :: forall a . Eq a => [a] -> [a] -> Bool
• List.isPrefixOf :: forall a . Eq a => [a] -> [a] -> Bool
• List.isSubsequenceOf :: forall a . Eq a => [a] -> [a] -> Bool
• List.isSuffixOf :: forall a . Eq a => [a] -> [a] -> Bool
• List.iterate' :: forall a . (a -> a) -> a -> [a]
• List.length :: forall a . [a] -> Int
• List.lookup :: forall a b . Eq a => a -> [(a, b)] -> Maybe b
• List.map :: forall a b . (a -> b) -> [a] -> [b]
• List.mapAccumL :: forall s a b . (s -> a -> (s, b)) -> s -> [a] -> (s, [b])
• List.mapAccumR :: forall s a b . (s -> a -> (s, b)) -> s -> [a] -> (s, [b])
• List.nil :: forall a . [a]
• List.notElem :: forall a . Eq a => a -> [a] -> Bool
• List.nubOrd :: forall a . Ord a => [a] -> [a]
• List.null :: forall a . [a] -> Bool
• List.or :: [Bool] -> Bool
• List.partition :: forall a . (a -> Bool) -> [a] -> ([a], [a])
• List.permutations :: forall a . [a] -> [[a]]
• List.repeat :: forall a . a -> [a]
• List.reverse :: forall a . [a] -> [a]
• List.scanl' :: forall a b . (b -> a -> b) -> b -> [a] -> [b]
• List.scanr :: forall a b . (a -> b -> b) -> b -> [a] -> [b]
• List.sort :: forall a . Ord a => [a] -> [a]
• List.sortOn :: forall a b . Ord b => (a -> b) -> [a] -> [a]
• List.span :: forall a . (a -> Bool) -> [a] -> ([a], [a])
• List.splitAt :: forall a . Int -> [a] -> ([a], [a])
• List.subsequences :: forall a . [a] -> [[a]]
• List.tails :: forall a . [a] -> [[a]]
• List.take :: forall a . Int -> [a] -> [a]
• List.takeWhile :: forall a . (a -> Bool) -> [a] -> [a]
• List.transpose :: forall a . [[a]] -> [[a]]
• List.uncons :: forall a . [a] -> Maybe (a, [a])
• List.unfoldr :: forall a b . (b -> Maybe (a, b)) -> b -> [a]
• List.zip :: forall a b . [a] -> [b] -> [(a, b)]
• List.zipWith :: forall a b c . (a -> b -> c) -> [a] -> [b] -> [c]

Map

• Map.adjust :: forall k a . Ord k => (a -> a) -> k -> Map k a -> Map k a
• Map.all :: forall k a . (a -> Bool) -> Map k a -> Bool
• Map.any :: forall k a . (a -> Bool) -> Map k a -> Bool
• Map.delete :: forall k a . Ord k => k -> Map k a -> Map k a
• Map.elems :: forall k a . Map k a -> [a]
• Map.filter :: forall k a . (a -> Bool) -> Map k a -> Map k a
• Map.filterWithKey :: forall k a . (k -> a -> Bool) -> Map k a -> Map k a
• Map.fromList :: forall k a . Ord k => [(k, a)] -> Map k a
• Map.insert :: forall k a . Ord k => k -> a -> Map k a -> Map k a
• Map.insertWith :: forall k a . Ord k => (a -> a -> a) -> k -> a -> Map k a -> Map k a
• Map.keys :: forall k a . Map k a -> [k]
• Map.lookup :: forall k a . Ord k => k -> Map k a -> Maybe a
• Map.map :: forall a b k . (a -> b) -> Map k a -> Map k b
• Map.singleton :: forall k a . Ord k => k -> a -> Map k a
• Map.size :: forall k a . Map k a -> Int
• Map.toList :: forall k a . Map k a -> [(k, a)]
• Map.unionWith :: forall k a . Ord k => (a -> a -> a) -> Map k a -> Map k a -> Map k a

Maybe

• Maybe.Just :: forall a . a -> Maybe a
• Maybe.Nothing :: forall a . Maybe a
• Maybe.listToMaybe :: forall a . [a] -> Maybe a
• Maybe.mapMaybe :: forall a b . (a -> Maybe b) -> [a] -> [b]
• Maybe.maybe :: forall a b . b -> (a -> b) -> Maybe a -> b

Monad

• Monad.bind :: forall m a b . Monad m => m a -> (a -> m b) -> m b
• Monad.forM :: forall a b m . Monad m => [a] -> (a -> m b) -> m [b]
• Monad.forM_ :: forall a m . Monad m => [a] -> (a -> m ()) -> m ()
• Monad.mapM :: forall a b m . Monad m => (a -> m b) -> [a] -> m [b]
• Monad.mapM_ :: forall a m . Monad m => (a -> m ()) -> [a] -> m ()
• Monad.return :: forall a m . Monad m => a -> m a
• Monad.sequence :: forall a m . Monad m => [m a] -> m [a]
• Monad.then :: forall m a b . Monad m => m a -> m b -> m b
• Monad.when :: forall m . Monad m => Bool -> m () -> m ()

Option

• Option.help :: forall a . Text -> Mod OptionFields a
• Option.long :: forall a . Text -> Mod OptionFields a
• Option.value :: forall a . a -> Mod OptionFields a

Options

• Options.execParser :: forall a . ParserInfo a -> IO a
• Options.flag :: forall a . a -> a -> Mod FlagFields a -> Parser a
• Options.flag' :: forall a . a -> Mod FlagFields a -> Parser a
• Options.fullDesc :: forall a . InfoMod a
• Options.helper :: forall a . Parser (a -> a)
• Options.info :: forall a . Parser a -> InfoMod a -> ParserInfo a
• Options.strArgument :: Mod ArgumentFields Text -> Parser Text
• Options.strOption :: Mod OptionFields Text -> Parser Text
• Options.switch :: Mod FlagFields Bool -> Parser Bool

Ord

• Ord.gt :: forall a . Ord a => a -> a -> Bool
• Ord.lt :: forall a . Ord a => a -> a -> Bool

Process

• Process.nullStream :: forall (a :: StreamType) . StreamSpec a ()
• Process.proc :: Text -> [Text] -> ProcessConfig () () ()
• Process.runProcess :: forall a b c . ProcessConfig a b c -> IO ExitCode
• Process.runProcess_ :: forall a b c . ProcessConfig a b c -> IO ()
• Process.setEnv :: [(Text,Text)] -> ProcessConfig () () () -> ProcessConfig () () ()
• Process.setStderr :: forall stdin stdout stderr stderr' . StreamSpec 'STOutput stderr' -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr'
• Process.setStdin :: forall stdin stdin' stdout stderr . StreamSpec 'STInput stdin' -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin' stdout stderr
• Process.setStdout :: forall stdin stdout stdout' stderr . StreamSpec 'STOutput stdout' -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout' stderr
• Process.setWorkingDir :: forall a b c . Text -> ProcessConfig a b c -> ProcessConfig a b c
• Process.useHandleClose :: forall (a :: StreamType) . Handle -> StreamSpec a ()
• Process.useHandleOpen :: forall (a :: StreamType) . Handle -> StreamSpec a ()

Record

• Record.get :: forall (k :: Symbol) a (t :: Symbol) (xs :: List) . Tagged t (Record xs) -> a
• Record.modify :: forall (k :: Symbol) a (t :: Symbol) (xs :: List) . (a -> a) -> Tagged t (Record xs) -> Tagged t (Record xs)
• Record.set :: forall (k :: Symbol) a (t :: Symbol) (xs :: List) . a -> Tagged t (Record xs) -> Tagged t (Record xs)

Set

• Set.delete :: forall a . Ord a => a -> Set a -> Set a
• Set.difference :: forall a . Ord a => Set a -> Set a -> Set a
• Set.fromList :: forall a . Ord a => [a] -> Set a
• Set.insert :: forall a . Ord a => a -> Set a -> Set a
• Set.intersection :: forall a . Ord a => Set a -> Set a -> Set a
• Set.member :: forall a . Ord a => a -> Set a -> Bool
• Set.singleton :: forall a . Ord a => a -> Set a
• Set.size :: forall a . Set a -> Int
• Set.toList :: forall a . Set a -> [a]
• Set.union :: forall a . Ord a => Set a -> Set a -> Set a

Show

• Show.show :: forall a . Show a => a -> Text

Temp

• Temp.withSystemTempDirectory :: forall a . Text -> (Text -> IO a) -> IO a
• Temp.withSystemTempFile :: forall a . Text -> (Text -> Handle -> IO a) -> IO a

Text

• Text.appendFile :: Text -> Text -> IO ()
• Text.breakOn :: Text -> Text -> (Text,Text)
• Text.concat :: [Text] -> Text
• Text.decodeUtf8 :: ByteString -> Text
• Text.drop :: Int -> Text -> Text
• Text.dropEnd :: Int -> Text -> Text
• Text.encodeUtf8 :: Text -> ByteString
• Text.eq :: Text -> Text -> Bool
• Text.getContents :: IO Text
• Text.getLine :: IO Text
• Text.hPutStr :: Handle -> Text -> IO ()
• Text.interact :: (Text -> Text) -> IO ()
• Text.intercalate :: Text -> [Text] -> Text
• Text.isInfixOf :: Text -> Text -> Bool
• Text.isPrefixOf :: Text -> Text -> Bool
• Text.isSuffixOf :: Text -> Text -> Bool
• Text.length :: Text -> Int
• Text.lines :: Text -> [Text]
• Text.putStr :: Text -> IO ()
• Text.putStrLn :: Text -> IO ()
• Text.readFile :: Text -> IO Text
• Text.readProcess :: ProcessConfig () () () -> IO (ExitCode,Text,Text)
• Text.readProcessStdout_ :: ProcessConfig () () () -> IO Text
• Text.readProcess_ :: ProcessConfig () () () -> IO (Text,Text)
• Text.replace :: Text -> Text -> Text -> Text
• Text.reverse :: Text -> Text
• Text.setStdin :: Text -> ProcessConfig () () () -> ProcessConfig () () ()
• Text.splitOn :: Text -> Text -> [Text]
• Text.strip :: Text -> Text
• Text.stripPrefix :: Text -> Text -> Maybe Text
• Text.stripSuffix :: Text -> Text -> Maybe Text
• Text.take :: Int -> Text -> Text
• Text.takeEnd :: Int -> Text -> Text
• Text.toLower :: Text -> Text
• Text.toUpper :: Text -> Text
• Text.unlines :: [Text] -> Text
• Text.unwords :: [Text] -> Text
• Text.words :: Text -> [Text]
• Text.writeFile :: Text -> Text -> IO ()

These

• These.That :: forall a b . b -> These a b
• These.These :: forall a b . a -> b -> These a b
• These.This :: forall a b . a -> These a b
• These.these :: forall a b c . (a -> c) -> (b -> c) -> (a -> b -> c) -> These a b -> c

TimeOfDay

• TimeOfDay.makeTimeOfDayValid :: Int -> Int -> Double -> Maybe TimeOfDay
• TimeOfDay.midday :: TimeOfDay
• TimeOfDay.midnight :: TimeOfDay
• TimeOfDay.timeOfDayToTime :: TimeOfDay -> Double
• TimeOfDay.timeToTimeOfDay :: Double -> TimeOfDay
• TimeOfDay.todHour :: TimeOfDay -> Int
• TimeOfDay.todMin :: TimeOfDay -> Int
• TimeOfDay.todSec :: TimeOfDay -> Double

Timeout

• Timeout.timeout :: forall a . Int -> IO a -> IO (Maybe a)

Tree

• Tree.Node :: forall a . a -> [Tree a] -> Tree a
• Tree.flatten :: forall a . Tree a -> [a]
• Tree.foldTree :: forall a b . (a -> [b] -> b) -> Tree a -> b
• Tree.levels :: forall a . Tree a -> [[a]]
• Tree.map :: forall a b . (a -> b) -> Tree a -> Tree b
• Tree.unfoldTree :: forall a b . (b -> (a, [b])) -> b -> Tree a

Tuple

• Tuple.(,) :: forall a b . a -> b -> (a, b)
• Tuple.(,,) :: forall a b c . a -> b -> c -> (a, b, c)
• Tuple.(,,,) :: forall a b c d . a -> b -> c -> d -> (a, b, c, d)

UTCTime

• UTCTime.UTCTime :: Day -> Double -> UTCTime
• UTCTime.addUTCTime :: Double -> UTCTime -> UTCTime
• UTCTime.diffUTCTime :: UTCTime -> UTCTime -> Double
• UTCTime.getCurrentTime :: IO UTCTime
• UTCTime.iso8601ParseM :: Text -> Maybe UTCTime
• UTCTime.iso8601Show :: UTCTime -> Text
• UTCTime.utctDay :: UTCTime -> Day
• UTCTime.utctDayTime :: UTCTime -> Double

Vector

• Vector.fromList :: forall a . [a] -> Vector a
• Vector.toList :: forall a . Vector a -> [a]