[Haskell] Parsing binary data

Folks, I'm trying to parse chunks of binary data that arrive through a socket. There's a defined format of these chunks where the first 4 bytes are an id, then could come a Pascal (size first) string, then some more data. I'm trying to figure out how to read and write Haskell data in this format and using a socket. Would someone have examples? Thanks, Joel -- http://wagerlabs.com/tech