cue VS starlark-rust

I'm continuing to work on https://concise-encoding.org which is a new security-conscious ad-hoc encoding format to replace JSON/XML and friends. I've been at it for 3 years so far and am close to a release.

In a nutshell:

- Edit in text, transmit in binary. One can be seamlessly converted to the other, but binary is far more efficient for processing, storage and transmission, while text is better for humans to read and edit (which happens far less often than the other things).

- Secure by design: Everything is tightly specced and accounted for so that there aren't differences between implementations that can be exploited to compromise your system. https://github.com/kstenerud/concise-encoding/blob/master/ce...

- Real type support because coercing everything into strings sucks (and is another security risk and source of incompatibilities).

XML had a good run but was replaced by JSON which was a big improvement. JSON also had a good run but it's time for it to retire now that the landscape has changed even further: Security and efficiency are the desires of today, and JSON provides neither.

I've got the spec nailed down and can finally see the light at the end of the tunnel for the reference implementation in golang. I still need to come up with a system for schemas, but I'm hoping that https://cuelang.org will fit the bill.

Has anyone taken a look at Cue who can share any experiences?

https://cuelang.org/

It's mentioned on the site as an alternative to Yaml. Recently watched (~half of) this intro to it: https://youtu.be/fR_yApIf6jU

the most interesting summary explanation of cue lang and its differences is from a bug filing - https://github.com/cuelang/cue/issues/33

>CUE is a bit different from the languages used in linguistics and more tailored to the general configuration issue as we've seen it at Google. But under the hood it adheres strictly to the concepts and principles of these approaches and we have been careful not to make the same mistakes made in BCL (which then were copied in all its offshoots). It also means that CUE can benefit from 30 years of research on this topic. For instance, under the hood, CUE uses a first-order unification algorithm, allowing us to build template extractors based on anti-unification (see issue #7 and #15), something that is not very meaningful or even possible with languages like BCL and Jsonnet.

I agree with you. Personally, I think Cue is much better than either YAML, TOML or JSON because it adds the concept of types to the idea of describing configuration.

true, but the tooling and workflow remains the same.

Not sure of any tool that could abstract the details sufficiently to be widely adopted. There is just too much nuance in cloud config.

I'm exploring using CUE (https://cuelang.org) to define TF resources, exporting as JSON for TF. So far it's much nicer

I haven't seen anyone mention starlark yet. It's something I want to play with as a config language.

Aside from these, if you want some inspiration for a production-grade language built in Rust, you might want to go through the source code of Starlark and Gluon.

There is also a Rust implementation of Starlark as a starting point https://github.com/facebookexperimental/starlark-rust

To add to everyone else, please don't use YAML. Starlark is great _precisely_ because it is a readable, well known (nearly Python) language that is limited at the same time (no unbounded for loops, no way to do non-deterministic things like get the current time or `random()`).

This is a follow-up to Benchmarking mlua/rlua/rhai - Rust embedded scripting languages from 4mo ago; I just added the new Starlark implementation from Meta to the benchmark posted by @aleksru.

The Rust implementation has it as an experimental extension (https://github.com/facebookexperimental/starlark-rust/blob/m...)

u/ndmitchell has been working on a Starlark interpreter. He wrote up a blog post with some thoughts about different interpreter styles. He found that in his case using fixed sized instructions was about the same as byte-encoded ones, but compiling the AST to closures was also about the same performance as well, and doesn't need an AST->bytecode compiler.

As mentioned in other comments, type system features like algebraic data types (that Rust has) are really helpful. If you want a small-but-real example of a compiler in Rust (with an optimizer etc) then the starlark-rust compiler is good.

If your Rust program needs a more complicated configuration (conditionals, access to APIs and so on), also look at Facebook's Starlark parser and tooling[1]. Starlark is a subset of Python used by Bazel, Buck and a few other projects.

[1]: https://github.com/facebookexperimental/starlark-rust

The Facebook post gives a nice overview. It also links out to the home page for the project at https://github.com/facebookexperimental/starlark-rust/, which has an introduction and links to what Starlark is, the crates.io link, the docs.rs link etc.