This simple utility wraps an IORef around random for the common use case of initializing an RNG once and using it in various places within an IO context. The haddocks should otherwise be self explanatory.
Any comments, improvement opportunities, feedback most welcome.
In version 0.3.0, rng-utils switched from targeting
random sees more use in the Haskell ecosystem, has fewer
dependencies and the performance difference was negligible in
comparison to the concurrency mechanism. If you feel strongly that
mwc-random should be part of the library, let us know in an issue
and we can look into supporting multiple backends.
- Switch to IORef instead of MVar. This should provide better performance under high contention.
- Swap out internal RNG for System.Random. It turns out that the gains to be had by using mwc-random are outshadowed by the mutation inherent to this library, so it is preferable to leverage System.Random which appears to be more commonly used and has better coverage of types to generate.
- Add rngRIO and rngIO convenience functions for generating values.