On 25 May 2010 12:20, Magicloud Magiclouds
This is the function. The problem sure seems like something was preserved unexpected. But I cannot find out where is the problem.
seperateOutput file = let content = lines file indexOfEachOutput_ = fst $ unzip $ filter (\(i, l) -> " Log for " `isPrefixOf` l ) $ zip [0..] content indexOfEachOutput = indexOfEachOutput_ ++ [length content] in
^^^^^^^^^^^^^^^^ Expensive bit
map (\(a, b) -> drop a $ take b content ) $ zip indexOfEachOutput $ tail indexOfEachOutput
You're not "streaming" the String; you're also keeping it around to calculate the length (I'm also not sure how GHC optimises that if at all; it might even re-evaluate the length each time you use indexOfEachOutput. The zipping of indexOfEachOutput should be OK without that length at the end, as it will lazy construct the zipped list (only evaluating up to two values at a time). However, you'd be better off using "zipWith f" rather than "map f . zip". -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com