I was a bit curious to learn what the differences are between this and the actor model, and I found this lobste.rs discussion to be helpful: https://lobste.rs/s/gsjskz/behavior_oriented_concurrency_for

> In BoC, the equivalent of a message is received by multiple actors and operates with exclusive access to the message and all of the receivers.

(emphasis mine)

IIUC with actors, messages are processed by exactly one actor so it can be difficult to express transactions (e.g. transferring funds from A to B cannot be done atomically). Erlang somewhat fixes this with "selective receive" which re-introduces the possibility of deadlocks. BoC fixes both issues.

Apart from installation problems/crash issues, do you have some feedback about type checking with ty vs. pyrefly? Which is stricter, soundness issues, etc?

Both are rust/open-source/new/fast so it's difficult to understand why I should choose one over the other.

For inextensible cloth there's also "Efficient simulation of inextensible cloth" [0] that is particularly clever and efficient

[0] https://dl.acm.org/doi/10.1145/1276377.1276438

Also check out Jean Gallier's notes (available online) https://www.cis.upenn.edu/~jean/gbooks/manif.html

Nice! It would be interesting to visualize the total momentum vector, IIRC Verlet being symplectic should be good at preserving symmetries, whereas RK4 is good at conserving energy.

I've been programming in c++ for 25 years (15 professionally) and I really don't see any reason to keep using it apart from dealing with legacy codebases.

Most arguments in the article boil down to "c++ has the reputation of X, which is partly true, but you can avoid problems with discipline". Amusingly, this also applies to assembly. This is _exactly_ why I don't want to code in c++ anymore: I don't want the constant cognitive load to remember not to shoot myself in the foot, and I don't want to spend time debugging silly issues when I screw up. I don't want the outdated tooling, compilation model and such.

Incidentally, I've also been coding in Rust for 5 years or so, and I'm always amazed that code that compiles actually works as intended and I can spend time on things that matter.

Going back to c++ makes me feel like a caveman coder, every single time.

Exactly. I’ve been using „Stupid Rust“ for years now where I just liberally clone if I can’t have my way. It‘s not bitten me yet and once the code compiles, it works.

Thanks, I scanned through all the comments/links but this is the actual resource one wants to read to get familiar with Backpack.

my tl;dr: after reading the article:

- two 64-bits words representation

- fixed, 32 bits length

- short strings (<12 bytes) are stored in-place

- long strings store a 4 byte prefix in-place + pointer to the rest

- two bits are used as flags in the pointer to further optimize some use-cases

Seems like they missed an opportunity to have a 8 byte version for strings that fit in the 4 byte prefix.

That was a nice read, thanks.

A quick comparison of the two languages would be interesting, in case anyone has experience with both.