> On Jan 11, 2018, at 11:15 PM, Jean-Daniel via swift-evolution 
> <swift-evolution@swift.org> wrote:
> A question about the new #unknown behavior. Is it intended to be used for 
> error handling too ?
> Will it be possible to use in catch clause ?

If we go with the #unknown approach, then yes of course it will work in catch 
clauses.  They are patterns, so it naturally falls out.

If we go with the “unknown default:” / “unknown case:"  approach, then no, this 
has nothing to do with error handling.

IMO, this pivots on the desired semantics for “unknown cases in enums”: if you 
intentionally try to match on this, do we get a warning or error if you don’t 
handle all the cases?  If we can get to consensus on that point, then the 
design is pretty obvious IMO.


swift-evolution mailing list

Reply via email to