On Wed, Aug 15, 2007 at 06:23:24PM +0100, Brian Hulley wrote:
Hi, On http://hackage.haskell.org/trac/haskell-prime/wiki/LambdaCase the proposed syntax for lambda case is:
case of alts
but this has a really bad downside for interactive editors: it doesn't allow one to distinguish between an incomplete construct and a completed construct thus removing one opportunity for an editor to alert the user (eg by highlighting) that there is something missing in the program text.
It's not like the current language has that property; consider (map myFunction) - is that an error or a partial application? I don't hold out much hope for context-free smart editors. You'll need a typechecker to do much of use, and that can easily distinguish lambda cases from regular cases... OTOH, your proposal provides (IMO) much more natural syntax for multi-pattern anonymous functions, especially if we stipulate that unlike a case (but like a lambda) you can have multiple arguments; then you could write stuff like: sumTo0 = foldr (\of 0 k -> 0 n k -> n + k) 0 Anyone else like this? Stefan