Hi Alex,

I think I would have avoided most of the problems in the first place. I'm finding the documentation to be rather undiscoverable at the moment, but I'm sure it's just a question of learning my way around it.

Make sure to keep http://haskell.org/ghc/docs/latest/html/libraries/ on your favorites list.

...

Represent your big iteration as a list. Try to stick to fairly simple operations on the list. Then the compiler will figure out how to keep things lazy and also release memory as it goes along.

See, this is what I thought I was doing, but I couldn't see where to simplify it further.

Sorry, you're right, I was begging the question. Hmm. Well, for starters: o Try to keep your big list far away from the IO monad. o Whenever possible, use the following library functions rather than manual recursion for iterating over your big list: take, takeWhile, drop, dropWhile, map, concatMap, filter, zip, zipWith. Browse around the wiki in places like: http://haskell.org/haskellwiki/Stack_overflow http://haskell.org/haskellwiki/Performance/Laziness http://haskell.org/haskellwiki/Performance/Strictness http://haskell.org/haskellwiki/Category:Style http://haskell.org/haskellwiki/Category:Tutorials -Yitz