Proposal: Add Eq instance for Control.Exception.ErrorCall

[Simon Marlow]

On 27/11/12 10:59, Simon Hengel wrote:
> Hi,
> I propose to add an Eq instance for ErrorCall.  The main motivation is
> to make it more convenient to construct predicates that select specific
> exceptions.
>
> My current use case is testing for expected exceptions.  In Hspec[1] we
> use predicates for that, e.g.:
>
>    evaluate (head []) `shouldThrow` (== ErrorCall "Prelude.head: empty list")
>
> But I think it can be useful in other situations and it is consistent
> with the fact that other common exception types have an Eq instance
> (e.g. ArithException, IOException, ExitCode).
>
> Discussion period: 3 Weeks

Already did it, a few weeks ago:

http://www.haskell.org/pipermail/cvs-libraries/2012-October/016043.html


Cheers,
	Simon