As of at least recently, empty cases are entirely permitted (and used for e.g. Void / nullary types). On Wed, Jun 26, 2019 at 3:08 PM Johannes Waldmann < johannes.waldmann@htwk-leipzig.de> wrote:
The rule "alt" allows "(empty alternative)"
Ah, yes. But no? The standard says
A case expression must have at least one alternative and each alternative must have at least one body.
Should this be "each non-empty alternative must have ..."?
I think the intention is to allow
case () of () | False -> () | True -> ()
(one alternative, two bodies) but to disallow
case () of ()
(one alternative, no body)
- J. _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.
-- brandon s allbery kf8nh allbery.b@gmail.com