On Mon, 24 Sep 2007, Vimal wrote:
Hi all,
I was surprised to find out that the following piece of code:
length [1..] > 10
isnt lazily evaluated! I wouldnt expect this to be a bug, but in this case, shouldnt the computation end when the length function evaluation goes something like:
10 + length [11..]
?
If you used genericLength and had it returning this type with an appropriate Num instance: data Nat = Zero | Succ Nat then it'd be sufficiently lazy. As it is, an Int is something you either have or don't - you can't only evaluate "is it less than x" without having to fully evaluate it. -- flippa@flippac.org "The reason for this is simple yet profound. Equations of the form x = x are completely useless. All interesting equations are of the form x = y." -- John C. Baez