Hi. I'm pleased to announce the availability of my random-stream package. The cabalized package is available at: http://haskell.mperillo.ath.cx/random-stream-0.0.1.tar.gz Note that I have not uploaded it on Hackage, and I do not plan to upload it in the near future, at least until I will repute the package mature enough. From package description: Portable interface for the operating system source of pseudo random data. Supported sources are Unix /dev/urandom, Win32 CryptGenRandom and OpenSSL pseudo random numbers generator. This package is based on idea from os.urandom implementation, in CPython. The idea is to view the system pseudo random generator as a stream of infinite random bytes. So, I have used a lazy bytestring, and unsafePerformIO/unsafeInterleaveIO. The underlying data is: newtype Stream = Stream L.ByteString and the constructor *is exposed*. The package configuration *must* be done using a flag to specify the "source" to use. As an example: runghc Setup.hs configure -O2 -fHAVE_URANDOM runghc Setup.hs configure -O2 -fHAVE_SSL runghc Setup.hs configure -O2 -fHAVE_WIN32_CRYPT If the flag is not specified, the compilation will fail. Note that Windows it not yet supported. The stream generator implements tha RandomGen interface. Some notes: 1) The system *pseudo* random generator is used. As an example, on Linux, /dev/random produces "true" random numbers, but it may block if there is not enough entropy in the system. More details on http://en.wikipedia.org/wiki//dev/random 2) When reading data, the lazy bytestring chunk size is used. The default chunk size, however, is fine when reading from a regular file, but may not be the best choice when reading pseudo random numbers. For SSL (and Windows) support, the chunk size can be easily changed; but for Unix support this seems to not be possible, unless I reimplement hGetContents. The Data.ByteString.Lazy module have an hGetContentsN function. Unfortunately it is not exposed. I find this annoying; is it possible to export the *N functions from Data.ByteString.Lazy.Internal? 3) I have tested the package on Debian Linux Etch, using GHC 6.8.2. Feedback will be appreciate. I not sure about some details. Usage example: module Main where import System.Random import System.Random.Stream gen = mkStream l :: [Int] l = randoms gen :: [Int] main = do print l Manlio Perillo