All your ByteString are belong to us... Hello, I'm pleased to announce the beta release of vector-bytestring. This library provides the type ByteString which is defined as a type synonym for a storable Vector of Word8s (from the vector package): type ByteString = Data.Vector.Storable.Vector Word8 It exports the same API as the bytestring package except that the module names are prefixed with: Data.Vector.Storable.ByteString instead of Data.ByteString. The very ambitious goal of this package is that it will eventually replace our beloved bytestring package. By basing this package on vector, we can benefit from all the optimizations (like stream-fusion!) in that library. We will also have just a single library to test, debug and optimize. TEST-SUITE I ported the bytestring test-suite to vector-bytestring. You can run it using: $ cabal configure --enable-tests; cabal build; cabal test All 54800 tests pass! Only one property doesn't hold: prop_show :: ByteString -> Bool prop_show x = show x == show (unpack x) This is because I don't provide a custom Show instance for ByteStrings but use the one from Vector which shows a vector like "fromList [1,2,3]" instead as "\SOH\STX\ETX" like bytestring does. Hopefully this is not a problem in practice. BENCHMARKS I added a criterion based benchmark-suite to vector-bytestring. It consists of over 600 benchmarks that cover almost every function in the library. Also included are benchmarks which benchmark the fusion capabilities of the library. Run it using: $ cabal configure -fbenchmark; cabal build; $ dist/build/bench/bench --help Unfortunately, bytestring still out performs us in lots of benchmarks. I believe the primary cause of this is that most functions are implemented using stream-fusion. This is highly efficient if you use a composition of these functions because they will all fuse into one single efficient loop. However if your program uses only a single function, the stream based implementation is often less efficient than an implementation that works directly on a mutable vector (like most functions in bytestring). So what we want is to use stream-fusion where possible but use mutable vectors when our program doesn't fuse. Fortunately, Roman Leshchinskiy (author of vector) has an idea how to do this: http://trac.haskell.org/vector/ticket/60 Because we don't beat bytestring in all cases yet you should consider this a beta-release and not use it in production code. INSTALLING $ cabal install vector-bytestring API DOCS http://hackage.haskell.org/package/vector-bytestring-0.0.0.0 DEVELOPING $ git clone https://github.com/basvandijk/vector-bytestring Regards, Bas