Hi folks, sorry for multiple copies of this email, but my mailserver had a problem and thought I am sending spam which is hopefully not true. Since I got a replay allready I modified my mail a bit. I was wondering why we don't have an annotation or pragma for function to tell the compiler that we _need_ this particular recursive function to be unfolded. If the compiler cannot do this for some reason it should produce an error message to help you modifying your code. I have regularly problems that my code is either not strict enough or my functions are not unfolded. I find it annoying that this is a regular show stopper and consumes much time to fix. Here is an example: a search function for strings, which should return the index and the rest of the string after the first occurrence: search0 will not be unfolded by ghc -O even with {#- INLINE search0 -#} (I don't know why, it looks tail-recursive to me) whereas search1 is just fine. search0 :: Int -> String -> String -> (String, Int) search0 i [] _ = ([],i) search0 i haystack needle = let len = length needle in if isPrefixOf needle haystack then (drop len haystack, i+len) else search0 (seq i (i+1)) (drop 1 haystack) needle search1 :: Int -> String -> String -> (String, Int) search1 i [] _ = ([],i) search1 i haystack needle = let i = elemIndex True $ map (isPrefixOf needle) $ tails haystack len = length needle in case i of Just index -> (drop (index+len) haystack, index + len) Nothing -> ([],0) Regards! Georg -- ---- Georg Martius, Tel: +49 177 6413311 ----- ------- http://www.flexman.homeip.net ----------