Network.MQTT.Parser

Parsers for MQTT messages.

Documentation

type MessageParser a = StateT Word32 Parser a

Type of a parser that also keeps track of the remaining length.

message :: Parser SomeMessage

Parse any MQTT message.

Fixed Header

mqttHeader :: Parser (MsgType, MqttHeader)

Parser for the fixed header part of a MQTT message.

parseRemaining :: Parser Word32

Parse the 'remaining length' field that indicates how long the rest of the message is.

Message Body

mqttBody :: MqttHeader -> SMsgType t -> Word32 -> Parser (MessageBody t)

mqttBody header msgtype remaining» parses aMessage of type msgtype that is remaining bytes long.

connect :: MessageParser (MessageBody CONNECT)

connAck :: MessageParser (MessageBody CONNACK)

publish :: MqttHeader -> MessageParser (MessageBody PUBLISH)

subscribe :: MessageParser (MessageBody SUBSCRIBE)

subAck :: MessageParser (MessageBody SUBACK)

unsubscribe :: MessageParser (MessageBody UNSUBSCRIBE)

Utility functions

getTopic :: MessageParser Topic

Parse a topic name.

mqttText :: MessageParser MqttText

Parse a length-prefixed UTF-8 string.

parseMsgID :: MessageParser Word16

Synonym for anyWord16BE.

anyWord16BE :: (Num a, Bits a) => MessageParser a

Parse a big-endian 16bit integer.

anyWord8' :: MessageParser Word8

A lifted version of attoparsec's anyWord8 that also subtracts 1 from the remaining length.

ctxt :: String -> Parser a -> Parser a

ctxt' :: String -> MessageParser a -> MessageParser a

take' :: Word32 -> MessageParser ByteString

A lifted version of attoparsec's take that also subtracts the length.

parseLength :: Word32 -> MessageParser ()

Subtract n from the remaining length or fail if there is not enough input left.

toQoS :: (Num a, Eq a, Show a, Monad m) => a -> m QoS

Convert a number to a QoS. fail if the number can't be converted.