On Mon, Oct 20, 2003 at 10:23:00PM -0400, Derek Elkins wrote:
I've wondered for a while why Haskell 98 didn't provide strictness annotations for functions a la Clean and no implementations provide it as an extension (actually I don't know about NHC, but I'm pretty sure neither GHC nor Hugs do). Clean's solution seems easier to read and write and seems like it would be trivial (though possibly tedious) to implement.
I can't speak for why they weren't included in Haskell 98, but on occasion I have wanted something like f :: Int -> !Int -> Int f x y = foo which would translate to: f :: Int -> Int -> Int f _ y | seq y False = undefined f x y = foo although I am not sure how useful it would actually be. another thing which might be handy is ' !' completely analogous to $!, with the exact same precedence as normal functional application (think space-bang, just like dollar-bang) foo x !(y + z) will have the effect of evaluating the second argument before passing it to foo. of course this would conflict with array indexing without some lexing magic... John -- --------------------------------------------------------------------------- John Meacham - California Institute of Technology, Alum. - john@foo.net ---------------------------------------------------------------------------