Re: help from the community?

Taral wrote:

On 1/31/07, Conor McBride wrote:

...

So, as far as Haskell' is concerned, I'd favour forbidding non-empty cases, but only because I favour having some more explicit syntax for empty cases, further down the line.

I see nothing wrong with "case x of {}", with required braces. The layout rule never generates empty braces.

main = do a <- do b <- something case b of return a Doesn't the layout rule convert the above to: main = do { a <- do { b <- something; case b of {}}; return a} ^^ empty braces In any case I thought the layout rule was supposed to be regarded as just a convenience rather than making a distinction between explicit braces and braces added by the rule? Also, can anyone explain why empty case constructs are needed? Why not just write undefined? Brian. -- http://www.metamilk.com