[Certhas]

I don't know Chapel in detail, I was more thinking Hylo. I don't think Chapel has a clear value/reference semantics or ownership/lifetime story? Am I wrong here?

The Mojo docs include two sections dedicated to these topics:

https://mojolang.org/docs/manual/values/

https://mojolang.org/docs/manual/lifecycle/

The metaprogramming story seems to take inspiration from Zig, but the way comptime, parameters and ownership blend in Mojo seems relatively novel to me (as a spectator/layman):

https://mojolang.org/docs/manual/metaprogramming/

I was sort of paying attention to all these ideas and concepts two-three years ago from the sidelines (partially with the idea to learn how Julia could potentially evolve) but it's far from my area of expertise, I might well be getting stuff wrong.

[pjmlp]

You make use of 'owned', 'shared', 'unmanaged', 'borrowed'.

https://chapel-lang.org/docs/language/spec/classes.html#clas...

[Certhas]

I see, seems like the design is not complete and a work in progress (which is the same for Mojos Origins concept I think):

"The details of lifetime checking are not yet finalized or specified. Additional syntax to specify the lifetimes of function returns will probably be needed."

I think Rust proved that lifetimes, ownership and borrow checking can be useful for a mainstream language. The discussions in the Mojo context revolve on how to improve the ergonomics of these versus Rust.

[pjmlp]

Contrary to Mojo, plenty of people are using it in HPC, and is open source.

https://hpsf.io/blog/2026/hpsf-project-communities-to-gather...

https://developer.hpe.com/platform/chapel/home

See "Projects Powered by Chapel".

[Certhas]

So? What point are you making? A different language with different design philosophy, has success in a different niche than Mojo is targeting?

[pjmlp]

One is used in production already by key laboratories in HPC research, the other wants to be and is far away from being 1.0.

Chapel current version is 2.8.0.

[MohamedMabrouk]

I don't understand this framing, so? Cpp, Julia are more widely adopted, used in HPC. it does not mean that people shouldn't start, learn new languages.

[Certhas]

I don't think Mojo is targeting HPC at all.

[melodyogonna]

Mojo isn't that far away from 1.0. Some point this year is the target