[plt-scheme] Addition to SchemeUnit?

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Wed Dec 23 11:38:51 EST 2009

On Wed, Dec 23, 2009 at 10:19 AM, Noel Welsh <noelwelsh at gmail.com> wrote:
> Looks fine to me. Checks are meant to operate like functions, which is
> why you have to use the thunk in check-exn. A bunch of people have
> complained about this. I can see their point but I like the clean
> model, so I'm a bit torn. I could be persuaded to change check-exn.

FWIW, I think it is fine for the thunk to be put in by a macro. IMO,
there isn't much value to the premise of checks acting like functions
if you're passing thunks into them.

> I prefer checking the type of the exn rather than the error message.
> I.e. I tend to use a deeper exn hierarchy when I want to convey
> information on the error. This enables more flexible output than just
> using the message string. With the message string you're stuck with
> whatever it contains, which is not appropriate in all situations
> (think help a programmer debug vs presenting information to a user).

But for those that don't get to choose the exn, it seems nice to be
able to at least check the text of the error message. It also makes
schemeunit applicable to more situations and makes it a bit more


Posted on the users mailing list.