Re: [Haskell-beginners] System.USB.writeInterrupt -- confused by error message from type system

* Alexander Polakov [130227 16:29]:

* emacstheviking [130227 16:00]:

...

let payload = pack "\x00\x00\x00\x00" let endPoint = EndpointAddress 0 Out action <- writeInterrupt handle endPoint ^^^^^^^^^^^^^^ ^^^^^^ ^^^^^^^^ ^^^^^^^ writeInterrupt :: DeviceHandle -> EndpointAddress -> WriteAction

Uhhmm, sorry, I'm being stupid and confusing here (sleep deprived a bit). I was looking at WriteAction definition while writing this, which is: type WriteAction = ByteString -> Timeout -> IO (Size, Status) So, you have to supply ByteString and Timeout to use it as IO action (with <-):

(size, status) <- writeInterrupt handle endPoint payload 1000

or use let like Karol Samborski suggested. -- Alexander Polakov | plhk.ru