[Haskell-cafe] error handling (esp. IO/exceptions)

[Henning Thielemann]

On Tue, 14 Apr 2009, brian at lorf.org wrote:

> On Tuesday, 14.04.09 at 23:36, Miguel Mitrofanov wrote:
>> What about ErrorT monad transformer?
>
> I don't see how it helps in my situation. ErrorT doesn't catch
> exceptions, for example. Suppose I did make something like ErrorT that
> catches exceptions and turn them into Lefts. Where would (>>=) get my
> specific error constructor?

With explicit-exception you would call
    Exc.fromEitherT $ try $ execute path options

The package has some hidden modules, where I experiment with a special IO 
type that cannot throw exceptions.