[Haskell-cafe] ANN: rematch, an library for composable assertions with human readable failure messages

[Roman Cheplyaka]

* Tom Crayford <tcrayford at gmail.com> [2013-04-16 15:24:07+0100]
> Re the Control namespace, these matchers aren't exclusively a testing tool.
> I've been using the core api for other purposes as well (primarily for
> validating forms in user interfaces in conjunction with
> digestive-functors). I couldn't figure anything better to put it in apart
> from Control (I definitely don't want it in Test, even though that's going
> to be what most people use it for). I guess it could be in `Data`, but that
> doesn't sound much better to me.

Yeah, the distinction between Control and Data is often borderline.
Also, I've just recalled that Control.Unification also uses the Control
namespace, although I don't see any rationale behind that.
It's not that important anyway.

> I'm not amazingly strong at building more principled interfaces right now,
> so I guess that's something I'll improve on. Are there any concrete
> suggestions you have there? I'd *like* these to have an `Alternative`
> instance, but making `Applicative`/`Functor` instances is beyond me right
> now (I guess I'd have to change the core API for that to work out).

I'll see if I can sketch something in the next couple of days.

Roman