I have not been following the details, but yes, the strictness analyser only runs when you say -O, and without strictness analysis you can get different space behaviour. Sometimes more, sometimes less. In this case, strictness analysis helps. Simon | -----Original Message----- | From: haskell-cafe-bounces@haskell.org [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Jules | Bean | Sent: 10 December 2004 21:38 | To: GoldPython | Cc: Henning Thielemann; haskell-cafe | Subject: Re: [Haskell-cafe] Flattening tail recursion? | | | On 10 Dec 2004, at 20:33, GoldPython wrote: | | > Just compiled this with -O and it ran with no stack overflow. | > Evidently, no `seq` needed for this one. Using ghc 6.2.2. | > | > countLines l = countLines' 0 l | > countLines' n [] = n | > countLines' n (_:ls) = countLines' (n + 1) ls | > | | That's presumably the answer. GHC's strictness analyser *can* cope with | this situation but only under -O... whereas most of us where testing | under ghci... | | Confirmation from one of the Simons? | | Jules | | _______________________________________________ | Haskell-Cafe mailing list | Haskell-Cafe@haskell.org | http://www.haskell.org/mailman/listinfo/haskell-cafe