That's right! You solved the mystery of the magic number! --- Felipe Lessa wrote:
You can try to verify this by using L.toChunks and noting how many chunks are being created.
-- test.hs module Main where import System import System.IO import qualified Data.ByteString.Lazy.Char8 as L import qualified Data.ByteString.Char8 as S main = do args <- getArgs let n = read $ args !! 0 cs <- L.getContents let !a = L.take n cs !l = L.length a hPutStrLn stderr $ "first chunk : " ++ show (S.length $ head $ L.toChunks cs) mapM_ (print . L.length) $ L.lines cs print a $ ./gen | head -1000 | ./test 17000 +RTS -sstderr > /dev/null ./test 17000 +RTS -sstderr first chunk : 16384 gen: <stdout>: commitAndReleaseBuffer: resource vanished (Broken pipe) 4,085,671,308 bytes allocated in the heap 7,659,656 bytes copied during GC 1,091,072 bytes maximum residency (1001 sample(s)) 540,552 bytes maximum slop 5 MB total memory in use (1 MB lost due to fragmentation) Generation 0: 6507 collections, 0 parallel, 0.10s, 0.13s elapsed Generation 1: 1001 collections, 0 parallel, 0.09s, 0.10s elapsed INIT time 0.00s ( 0.00s elapsed) MUT time 2.62s ( 23.11s elapsed) GC time 0.19s ( 0.23s elapsed) EXIT time 0.00s ( 0.00s elapsed) Total time 2.81s ( 23.34s elapsed) %GC time 6.8% (1.0% elapsed) Alloc rate 1,558,678,834 bytes per MUT second Productivity 93.2% of total user, 11.2% of total elapsed -- Regards, Yasuo Uchida