On Tue, Aug 24, 2010 at 11:34 AM, Adam Chlipala <[email protected]> wrote: > This is certainly a thorough list of ways of supporting general > exception-handling, but I had hoped (and continue to hope) Ur wouldn't need > any such facility. ;) > > Why can't you just check for uniqueness constraint violations in your code > before inserting into the database? I can see the case for a simple > facility for specifying an alternate error-reporting page, but more than > that doesn't seem worthwhile. These errors should only come up in buggy > programs.
Unless you move these checks into the DML itself, this requires an extra round-trip to the database. If issuing the check in the DML is infeasible or undesirable, for performance reasons, you really do want some kind of exception handling facility. (Though honestly, I tend to prefer to catch the exception close to the point that the DML is issued, and project it into a value such as the Either type... certainly the database access layer could do this for me, but they usually don't.) _______________________________________________ Ur mailing list [email protected] http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
