On 28 July 2005 15:05, Ian Lynagh wrote:

I couldn't see a way to write any of these functions without using GHC.IOBase. Did I miss one?

If not, can they (or something that would allow them to be written) please be added to System.IO.Error?

import GHC.IOBase ( IOException(ioe_location), IOErrorType(UnsupportedOperation, HardwareFault) )

add_to_error_loc :: Exception -> String -> Exception add_to_error_loc (IOException ioe) s = IOException $ ioe { ioe_location = s ++ ": " ++ ioe_location ioe } add_to_error_loc e _ = e

I don't think all implementations have a "location" field in their IOErrors, since it isn't required by Haskell 98. Interestingly, the GHC implementation of mkIOError fills in the location field rather than the description field, so I suspect you could use mkIOError to construct add_to_error_loc. One possibility is to add support for the location of an IOError to System.IO.Error.

isUnsupportedOperationError :: IOError -> Bool isUnsupportedOperationError = isUnsupportedOperationErrorType . ioeGetErrorType

isUnsupportedOperationErrorType :: IOErrorType -> Bool isUnsupportedOperationErrorType UnsupportedOperation = True isUnsupportedOperationErrorType _ = False

This one is easier. I'm happy for this to go in, if there are no objections. There are some other ErrorTypes that GHC supports that aren't in H98, IIRC. Cheers, Simon