martine: > On 5/14/06, Eugene Crosser <[EMAIL PROTECTED]> wrote: > >main = printMax . (foldr processLine empty) . lines =<< getContents > >[snip] > >The thing kinda works on small data sets, but if you feed it with > >250,000 lines (1000 distinct), the process size grows to 200 Mb, and on > >500,000 lines I get "*** Exception: stack overflow" (using runhaskell > >from ghc 6.2.4). > > To elaborate on Udo's point: > If you look at the definition of foldr you'll see where the stack > overflow is coming from: foldr recurses all the way down to the end > of the list, so your stack gets 250k (or attempts 500k) entries deep > so it can process the last line in the file first, then unwinds.
Also, don't use runhaskell! Compile the code with -O :) -- Don _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
