[Haskell-cafe] Please help me spot where space leak occur.

[Jason Dagit]

On Fri, Jul 22, 2011 at 1:54 AM, Olexander Kozlov <ookozlov at gmail.com> wrote:
> Jason, thank you for your help. The hint for using -s option is very
> valuable.
> It is good to see people answering questions about Haskell here on
> haskell-cafe.

stackoverflow is another good place to ask.

> This is really matter. I hope I will be helpfull some day too :)
> As for the question I didn't mention in my psot that Fn can be of arbitrary
> size.

You could extend my solution pretty easily to work for arbitrary size.

> Now I have another question which I'm concerned with. I used foldl' (strict)
> in my implementation
> instead of just foldl (lazy). Does it mean that libraries are to be in two
> implementations one strict
> and another one lazy? Because there no way to affect strictness/lazyness of
> function without modifying
> its implementation. I' going to ask this question as a separate thread.

It doesn't come up that much.  It comes up here with your foldl, with
Chans, modifyIORef, modifySTRef, and a few things like that.  But most
of the time you want a lazy version until you spot a space leak.  Most
of the time the library creator notices and makes a strict version as
needed.  One of the nice things about Haskell is that you get a choice
between lazy and strict, and lazy by default is nice in many ways.
Space leaks like this are not usually show stoppers for experienced
Haskell folks.

Good luck!
Jason