Haskell Space Overflow

Question

I\'ve compiled this program and am trying to run it.

import Data.List
import Data.Ord
import qualified Data.MemoCombinators as Memo

collatzLength :: Int -&g         


        

Answer 1

Use the optimizer (via the -O2 flag) any time you are concerned about performance. GHC's optimizations are hugely important not just to run time but to stack use. I've tested this with GHC 7.2 and optimization takes care of your issue.

EDIT: In addtion, if you're on a 32 bit machine be sure to use Int64 or Word64. You'll overflow the size of a 32 bit int and cause non-termination otherwise (thanks to Henning for this, upvote his answer).