Comment by LightMachine
2 years ago
Where have you read that HVM beats C or Rust? That is not something I've ever written and we're far from that, specially considering the budget that has been thrown into Rust, although we could (and hope to) get there one day. This is possible in theory, because interaction nets are as lightweight as Rust, but have the added benefit of built-in parallelism. Please see the whole FAQ, I think it addresses all your questions. Let me know if you have any further questions.
Thanks for the reply. The FAQ doesn't really answer my specific questions, but I understand that HVM is still young and there aren't answers to everything yet.
The FAQ mentions that every reduction rule can be compiled to machine code in theory. That's the core of what I'm asking - can reduction be implemented efficiently? I suspect it's not enough to have fast reduction rules, because that still requires a runtime that spends CPU cycles and memory accesses on reduction housekeeping. To be fast you need to minimize explicit reduction at runtime because that's not what CPUs are good at.
I guess an aggressive HVM compiler would find sub-programs that can be treated as leaf nodes and replaced entirely with compiled machine code. The machine code doesn't use interaction nets but it computes an equivalent result to the interaction net. This doesn't mean that reduction and interaction nets aren't used, they still serve a purpose for lazy evaluation and parallelism at higher levels of the program. The compiler would have to figure out where to draw the line between the high-level reduction runtime and the leaf nodes.
Anyway, this is just what comes to mind. I don't really know how HVM works, but thanks for sharing it.