datafrog VS differential-dataflow

What is the difference with https://github.com/rust-lang/datafrog? It’s a Datalog engine written by Frank McSherry on top of differential dataflow, that’s used here also

C++ is arguably the most complex programming language ever. There is not much to be gained by comparing against the supremum.

Take a look at the languages that rust was influenced by (https://en.wikipedia.org/wiki/Rust_(programming_language)) those aren't languages with straightforward compilation semantics.

There is a reason why rust has a datalog engine build into the compiler (https://github.com/rust-lang/datafrog). Which is imho totally rad and awesome, but really hard to fully form a mental model of without a spec.

Datalog may be obscure, but its actually what the next generation of the borrow checker is going to be implemented in, you may find inspiration here: https://github.com/rust-lang/datafrog

They used to but Frank McSherry (author of differential dataflow) wrote them a specialized version without all the dataflow infrastructure [1]. It's part of the rust-lang nursery [2] now but hasn't been updated in a while, so I'm not sure what happened to it.

[1] https://github.com/frankmcsherry/blog/blob/master/posts/2018...

[2] https://github.com/rust-lang/datafrog

Lets you define queries over some data set declaratively, and instead of recomputing the query over the entire data set every time you want an updated answer, it uses Differential Dataflow <https://github.com/frankmcsherry/differential-dataflow> to efficiently(^1) calculate the new results by updating the results of the previous query execution in response to new updates to the data set.

^1: I'm not an expert on Differential Dataflow, so I don't know what "efficiently" means in this context, other than "should be faster than running the query from scratch."