🚀 go-pugleaf

# datatype foo = Alpha of int | Beta of real | Gamma of string;
# datatype bar = Happy of int | Dopey of real | Grumpy of string;
# 
# fun testcase (x,y) =
#   case x of
#     Alpha _ => ()
#   | Beta _ =>
#       case y of
#         Happy _ => ()
#       | Dopey _ => ()
#       | Grumpy _ => ()
#   | Gamma _ => ();       (* Hmmm... *)
# 

Any SML compiler which accepts this is wrong, i.e., as I
read the rules an error message should be generated (sorry
I can't quote the rule numbers as the definition is at home).
However, having made the mistake, I agree that this bit
of SML syntax is a mis-feature.

In general, if a syntax is designed for small examples then
closing brackets can `be safely omitted'.  When the examples
start to get large the `safely' is invalidated.

The time spent (and the in elegance of) esac, fi, nf, etc. is
negligible compared with problems of mis-interpretation.