> Surely not... sum is defined by Haskell 98 as: > > sum = foldl (+) 0 > > and this is exactly what GHC provides. Furthermore we have > specialised strict versions for Int and Integer. >
I'd been using ghci for testing along the way and getting terrible results; does the specialization only apply to ghc per se? > > Cheers, > Simon > Also, Cale, I was thinking about your comment about formal power series, and I don't see that (+) should not be strict in this case. In particular, if they are represented as infinite lists, I agree that zipWith (+) works just fine, though it is strict but lazy. Here is the strictness: zipWith (+) undefined [1,2,3] == undefined zipWith (+) [1,2,3] undefined == undefined And here is the laziness: head $ zipWith (+) (1:undefined) (2:undefined) == 3 Or am I missing something? -Chad _______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
