I'm trying to translate this HXT code to use the Arrow 'do' syntax: readWriteDoc :: String -> IOSLA (XIOState s) b Int readWriteDoc path = readDocument [(a_validate, "0")] path >>> writeDocument [(a_output_encoding, isoLatin1)] "-" >>> getErrStatus This attempt fails to compile: readWriteDoc :: String -> IOSLA (XIOState s) b Int readWriteDoc = proc path -> do doc <- readDocument [(a_validate, "0")] -< path result <- writeDocument [(a_output_encoding, isoLatin1)] "-" -< doc getErrStatus -< result I get this error message: Couldn't match `(->)' against `IOSLA (XIOState s)' Expected type: t -> t1 Inferred type: IOStateArrow s XmlTree XmlTree Probable cause: `writeDocument' is applied to too many arguments in the call (writeDocument [(a_output_encoding, isoLatin1)] "-") In the command: writeDocument [(a_output_encoding, isoLatin1)] "-" -< doc Any idea what I'm doing wrong? Thanks, Greg