Comment Re:Not to sound like an ass, but... (Score 1) 173
Moreover, the DoAndIfThenElse extension merely extends the "do" syntax with if/then/else clauses; it is syntactic sugar. Empty data declarations are essentially union types unioned over no labels and therefore can have no values except for the bottom value.
References:
http://hackage.haskell.org/trac/haskell-prime/wiki/DoAndIfThenElse
http://hackage.haskell.org/trac/haskell-prime/wiki/EmptyDataDecls