Error +Control.Monad.Trans -transformers
An exception to be thrown.
Minimal complete definition: noMsg or strMsg.
This philosophy behind this package is that it is often better to find out all of the errors that have occured in a computation and report them simultaneously, rather than aborting as soon as the first error is encountered. Towards this end, this module supplies a type of combinable error messages so that all of the errors from subcomputations can be gathered and presented together.
New in version 1.1: Removed Monoid instance for Doc (it should now be supplied by ansi-wl-pprint), added ErrorMessageOr type alias.
Map the unwrapped computation using the given function.
* (mapErrorT f m) = f (runErrorT
A small library useful for error handling when making foreign calls to the Windows API. Error codes set by Windows are converted to Haskell exceptions and can be thrown and caught with the usual exception handling functions in Control.Exception.