The first version of Haskell VCache is now available on Hackage. Before installing VCache, you may need to `
sudo apt-get install lmdb-dev` on your Linux system, or install LMDB and its header files by some other means.
At this point, the primary features of VCache seem solid. PVars and VRefs are each first-class. The reference counting garbage collection is very simple. Structure sharing for values works. The concurrent aspects are kept simple, albeit bottlenecked at the moment by a single MVar. The batching mechanisms work very well. It seems easy to use, at least in ghci. But testing isn’t very rigorous.
There are performance improvements to be had, especially with respect to cache management.
But if you’re interested in an alternative to acid-state that can support very large values and fine-grained, first-class mutable variables, then give VCache a try. Also, let me know where the documentation can be improved.