Transient.Parse

Documentation

setParseStream :: IO (StreamData ByteString) -> TransIO ()

set a stream of strings to be parsed

setParseString :: ByteString -> TransIO ()

set a string to be parsed

withParseString :: ByteString -> TransIO a -> TransIO a

data ParseContext str

The parse context contains either the string to be parsed or a computation that gives an stream of strings or both. First, the string is parsed. If it is empty, the stream is pulled for more.

Constructors

IsString str => ParseContext (IO (StreamData str)) str

string :: ByteString -> TransIO ByteString

succeed if read the string given as parameter

tDropUntilToken :: ByteString -> TransIO ()

fast search for a token

tTakeUntilToken :: ByteString -> TransIO ByteString

integer :: TransIO Integer

read an Integer

int :: TransIO Int

read an Int

manyTill :: TransIO a -> TransIO b -> TransIO [a]

read many results with a parser (at least one) until a end parser succeed.

chainManyTill :: (Alternative f, Monad f, Monoid a1) => (t -> a1 -> a1) -> f t -> f a2 -> f a1

between :: Monad m => m a1 -> m a2 -> m b -> m b

symbol :: ByteString -> TransIO ByteString

parens :: TransIO b -> TransIO b

braces :: TransIO b -> TransIO b

angles :: TransIO b -> TransIO b

brackets :: TransIO b -> TransIO b

semi :: TransIO ByteString

comma :: TransIO ByteString

dot :: TransIO ByteString

colon :: TransIO ByteString

sepBy :: TransIO a -> TransIO x -> TransIO [a]

sepBy1 :: TransIO a -> TransIO x -> TransIO [a]

chainSepBy :: (Alternative f, Monad f, Monoid a1) => (a2 -> a1 -> a1) -> f a2 -> f x -> f a1

chainSepBy1 :: (Monad m, Monoid b, Alternative m) => (a -> b -> b) -> m a -> m x -> m b

chainMany :: (Alternative f, Monad f, Monoid a1) => (a2 -> a1 -> a1) -> f a2 -> f a1

commaSep :: TransIO a -> TransIO [a]

semiSep :: TransIO a -> TransIO [a]

commaSep1 :: TransIO a -> TransIO [a]

semiSep1 :: TransIO a -> TransIO [a]

dropSpaces :: TransIO ()

dropTillEndOfLine :: TransIO ()

parseString :: TransIO ByteString

tTakeWhile :: (Char -> Bool) -> TransIO ByteString

take characters while they meet the condition

tTakeWhile' :: (Char -> Bool) -> TransIO ByteString

take characters while they meet the condition and drop the next character

just1 :: (p -> (a, b)) -> p -> (Maybe a, b)

tTake :: Int64 -> TransIO ByteString

take n characters

tDrop :: Int64 -> TransIO ()

drop n characters

anyChar :: TransIO Char

read a char

tChar :: Char -> TransIO Char

verify that the next character is the one expected

withData :: (ByteString -> TransIO (a, ByteString)) -> TransIO a

bring the lazy byteString state to a parser and actualize the byteString state with the result The tuple that the parser should return should be : (what it returns, what should remain to be parsed)

giveData :: TransIO ByteString

bring the data of the parse context as a lazy byteString

isDone :: TransIO Bool

True if the stream has finished

(|-) :: TransIO (StreamData ByteString) -> TransIO b -> TransIO b

Chain two parsers. The motivation is to parse a chunked HTTP response which contains JSON messages.

If the REST response is infinite and contains JSON messages, I have to chain the dechunk parser with the JSON decoder of aeson, to produce a stream of aeson messages. Since the boundaries of chunks and JSON messages do not match, it is not possible to add a decode to the monadic pipeline. Since the stream is potentially infinite and/or the messages may arrive at any time, I can not wait until all the input finish before decoding the messages.

I need to generate a ByteString stream with the first parser, which is the input for the second parser.

The first parser wait until the second consume the previous chunk, so it is pull-based.

many parsing stages can be chained with this operator.

The output is nondeterministic: it can return 0, 1 or more results

example: https://t.co/fmx1uE2SUd