LunarML VS sml-parseq

While talking about this I discovered LunarML, which compiles StandardML to Lua and JS. I'm more familiar with OCaml than SML, but that's definitely one I'm going to keep an eye on.

Author here. One of the cool things about the property we're using here---disentanglement---is that it specifically allows for shared data, under only mild restrictions. This allows us, for example, to implement fast libraries which utilize shared mutable state for efficiency under the hood. A good example is our parallel arrays library (https://github.com/shwestrick/sml-parseq), which is "purely functional" in terms of its interface, but not its implementation.

It's helpful here to distinguish parallelism from concurrency. Disentanglement naturally emerges in data-race-free parallel programs, which have no concurrency. But certainly, you bring up a good point for programs that are highly concurrent in addition to being highly parallel. There's lots of work already on concurrent functional programming, for example CML (https://en.wikipedia.org/wiki/Concurrent_ML), and we think these ideas could be adapted to work with disentanglement really well.