[Haskell-cafe] Uncatchable error

[Henning Thielemann]

On Fri, 11 Mar 2011, Daniel Peebles wrote:

> Check out the spoon package on hackage. It's designed for these kinds of situations, and
> will wrap up common user-generated "pure" exceptions into a Maybe (and will return
> Nothing in the cases you describe)

This is a hack, since 'undefined' cannot be detected in general. The clean 
solution would be to find out where invalid file descriptors are detected 
in the IO code, and throw a real IOException instead of an 'error'.