Quoting Mikhail Vorozhtsov
After 21 months of occasional arguing the lambda-case proposal(s) is in danger of being buried under its own trac ticket comments. We need fresh blood to finally reach an agreement on the syntax. Read the wiki page[1], take a look at the ticket[2], vote and comment on the proposals!
P.S. I'm CC-ing Cafe to attract more people, but please keep the discussion to the GHC Users list.
[1] http://hackage.haskell.org/trac/ghc/wiki/LambdasVsPatternMatching [2] http://hackage.haskell.org/trac/ghc/ticket/4359
Well, for what it's worth, my vote goes for a multi-argument \case. I find the comment on the wiki page about mistyping "\case Just x" instead of "\case (Just x)" a lot a bit disingenuous, since you already need these parens with today's lambda. The complaint that multi-argument cases are unorthodox doesn't really hold a lot of weight with me -- much more serious things than syntax have changed in GHC compared to the Report! Is there a more formal way to cast votes...? ~d