Hey, I was looking at the reverse-complement benchmark on the Language Shootout, and among other things, I noticed that the Haskell implementation was using (filter (/= '\n')) on ByteStrings, and also using lists as queues. I had a few improvements which using -fasm seem to yield about a 19% improvement in speed, and a 35% reduction in allocation, on my computer. (If both programs are compiled with -fllvm -- I'm not sure whether or not that's fair game on the Shootout -- my implementation is 35% faster, and does 10% less allocation.) I've checked my code on the Shootout's test input, as well. Mostly, the improvement comes from a tightly specialized version of (filter (/= '\n')), although eliminating an intermediate list entirely (and one used in a queuelike fashion) didn't seem to hurt. I managed to cut the program to a point where the program size is about the same as before. The code is at http://hpaste.org/fastcgi/hpaste.fcgi/view?id=25865; the previous implementation is at http://shootout.alioth.debian.org/u32/program.php?test=revcomp&lang=ghc&id=2 . Let the arguing begin? Louis Wasserman wasserman.louis@gmail.com http://profiles.google.com/wasserman.louis