Caching features

[elidupree]

Caching can be important for efficiency, but it is inherently dangerous to determinism. Maybe we should provide caching types that are impossible to use unsafely and/or can have runtime checks enabled to detect whether they cause nondeterminism.

Constant caches can be included in a Basics::Constants. They should probably serialize to nothing by default. If we write consistency checks, they have to be done differently than field consistency checks (since caches are only required to be consistent between the simulations, but are allowed to be different from each other).

Maybe we can use adapton for this? It might be appropriate. It is not currently easy to learn (few examples), but if it turns out to be appropriate for this use, using it and writing our own examples would probably be better than implementing our own caching system from scratch.