Potoki.Core.Transform

Documentation

newtype Transform input output

Constructors

Transform (Fetch input -> Acquire (Fetch output))

consume :: Consume input output -> Transform input output

produce :: (input -> Produce output) -> Transform input output

mapFetch :: (Fetch a -> Fetch b) -> Transform a b

Basics

ioTransform :: IO (Transform a b) -> Transform a b

take :: Int -> Transform input input

takeWhile :: (input -> Bool) -> Transform input input

drop :: Int -> Transform input input

mapFilter :: (input -> Maybe output) -> Transform input output

filter :: (input -> Bool) -> Transform input input

just :: Transform (Maybe input) input

list :: Transform [a] a

vector :: Transform (Vector a) a

distinctBy :: (Eq comparable, Hashable comparable) => (element -> comparable) -> Transform element element

distinct :: (Eq element, Hashable element) => Transform element element

executeIO :: Transform (IO a) a

Execute the IO action.

mapInIO :: (a -> IO b) -> Transform a b

ByteString

builderChunks :: Transform Builder ByteString

extractLines :: Transform ByteString ByteString

Convert freeform bytestring chunks into chunks, which are strictly separated by newline no matter how long they may be.

State

runState :: (a -> State s b) -> s -> Transform a (s, b)

Notice that you can control the emission of output of each step by producing a list of outputs and then composing the transform with the "list" transform.

execState :: (a -> State s b) -> s -> Transform a s

evalState :: (a -> State s b) -> s -> Transform a b

Parsing

parseBytes :: Parser parsed -> Transform ByteString (Either Text parsed)

Lift an Attoparsec ByteString parser.

parseText :: Parser parsed -> Transform Text (Either Text parsed)

Lift an Attoparsec Text parser.

Concurrency

bufferize :: Int -> Transform element element

concurrently :: Int -> Transform input output -> Transform input output

Execute the transform on the specified amount of threads. The order of the outputs produced is indiscriminate.

async :: Int -> Transform input input

A transform, which fetches the inputs asynchronously on the specified number of threads.

File IO

deleteFile :: Transform FilePath (Either IOException ())

appendBytesToFile :: Transform (FilePath, ByteString) (Either IOException ())

writeTextToFile :: Transform (FilePath, Text) (Either IOException ())

Debugging

traceWithCounter :: (Int -> String) -> Transform a a

Useful for debugging