[plt-scheme] Idiomatic equivalent to exn:application in v299?

At Sun, 6 Feb 2005 13:47:51 -0500, Richard Cobbe wrote:
> In the old version, the lookup function would raise an
> exn:application:mismatch exception [...]
> 
> What's the idiomatic equivalent under v299?  It appears from the docs
> that the exn:fail:contract exception is the replacement for
> exn:application:mismatch, but there's no value field.

Right.

If you actually have a use for the value, then probably you want a new
sub-type of `exn:fail:contract'.

We dropped the value field for contract exceptions because no one
seemed to be using the value, and it was a lot of trouble for exception
raisers to make sure that a useful value (which was never actually
used) went into the field.

Matthew