On 2/10/07, Creighton Hogg <wchogg@gmail.com> wrote:
On 2/10/07, Lennart Augustsson <
lennart@augustsson.net> wrote:
There are many things that makes your code slow.
* The default for Haskell is to compute with Integer, not Int. So
that makes from Integral and floor very slow.
* foldl' is a bad choice, because it is too strict, you want to abort
the loop as soon as possible.
Now why is foldl' too strict? I don't think I understand?
I think I can explain my confusion better. For a finite list, I thought a fold would always pass through the entire list. I take it that what you mean is that, since the fold is over an &&, then it can bail as soon as it encounters the first false, but it only does that if it's allowed to not be strict. I suppose this reveals my ignorance of how laziness really works.