dhall-lang VS nix

Fail to see how this is any different than Dhall (https://dhall-lang.org/) other than it produces plists too.

Kubernetes config is a decent example. I had ChatGPT generate a representative silly example -- the content doesn't matter so much as the structure:

https://gist.github.com/cstrahan/528b00cd5c3a22e3d8f057bb1a7...

Now consider 100s (if not 1000s) of such files.

I haven't given Pkl an in depth look yet, but I can say that the Industry Standard™ of "simple YAML" + string substitution (with delicate, error prone indentation -- since YAML is indentation sensitive) is easily beat by any of:

- https://jsonnet.org/

- https://nickel-lang.org/

- https://nixos.org/manual/nix/stable/language/index.html

- https://dhall-lang.org/

- (insert many more here, probably including Pkl)

There are underpowered languages / tools, that can only solve a problem for which they are intended poorly. But not all limited tools are like that.

Say, eBPF is prominently not Turing-complete, which allows to guarantee that a eBPF program terminates, and even how soon. Still eBPF is hugely useful in its area.

Or, say, regular expressions are limited to regular languages; in particular, they famously [1] cannot process recursive structures, like trees. Still tools like grep / ag / rg are mightily useful.

Yes, I agree that YAML is underpowered for proper k8s configuration! But it's also too powerful for its own good in other aspects [2]. I wish Google used Dhall [3] or their own purely functional config language (FCL? I already forgot the name) instead of YAML; sadly, they did not.

[1]: https://stackoverflow.com/a/1732454/223424

[2]: https://ruudvanasseldonk.com/2023/01/11/the-yaml-document-fr...

[3]: https://dhall-lang.org/

Dhall: Dhall is a programmable configuration language that combines features like JSON, functions, types, and import capabilities. Its style leans towards functional programming, so if you're familiar with functional-style languages such as Haskell, you might find Dhall to be quite intuitive.

I've been thinking along these lines but more 'strongly validated' than statically typed in the sense that you'd be better off being able to load the entire config and then produce a list of problems (and should be able to offer good editor support if done correctly).

Though https://dhall-lang.org/ demonstrates that you can statically type quite a lot of configuration to great advantage, which appears to be programmatically embeddable in multiple languages per https://docs.dhall-lang.org/howtos/How-to-integrate-Dhall.ht...

> Where practical is in the sense of an engineer (or in their terms, a CS practitioner),

Configuration processing. E.g. I'd like my yamls to be decidable, though I'd settle for guaranteed to halt[1].

[1] https://dhall-lang.org/

Maybe you'd like jsonnet: https://jsonnet.org/

I find it particularly useful for configurations that often have repeated boilerplate, like ansible playbooks or deploying a bunch of "similar-but" services to kubernetes (with https://tanka.dev).

Dhall is also quite interesting, with some tradeoffs: https://dhall-lang.org/

A few years ago I did a small comparison by re-implementing one of my simpler ansible playbooks: https://github.com/retzkek/ansible-dhall-jsonnet

And to checkout Dhall: https://dhall-lang.org/

> https://github.com/NixOS/nix/pull/9911#issuecomment-19252073...

As we covered in my last post, NixOS is a amazing Linux distribution for creating stable and declared environments. Now while this is amazing for a desktop setup, it is also perfect for a home-server or home-lab.

(Nix itself is slowly chugging along with Windows via MinGW - https://discourse.nixos.org/t/nix-on-windows/1113/108 and https://github.com/NixOS/nix/issues/1320 , for example.)

Nix is a cross-platform package manager. It uses the nix programming language. Nix and NixOs are often used in the same context, but while the first is a package manager, the latter is a linux distribution based on nix.

Today I want to talk to you about Nixos. What is it? Nixos is a declarative and reproducible OS, partly taking the words used on their own page. What does that mean?

Software developers often want to customize:

1. their home environments: for packages (some reach for brew on MacOS) and configurations (dotfiles, and some reach for stow).

2. their development shells: for build dependencies (compilers, SDKs, libraries), tools (LSP, linters, formatters, debuggers), and services (runtime, database). Some reach for devcontainers here.

3. or even their operating systems: for development, for CI, for deployment, or for personal use.

Nix provision all of the above in the same language, with Nixpkgs, NixOS, home-manager, and devShells such as https://devenv.sh/. What's more, Nix is (https://nixos.org/):

- reproducible: what works on your dev machine also works in CI in prod,

- declarative: you version control and review your configurations and infrastructure as code, at a reasonable level of abstraction,

- reliable: all changes are atomic with easy roll back.

Hopping from one distro to another with a different package manager might require some time to adapt. Using a package manager that can be installed on most distro is one way to help you get to work faster. Flatpak is one of them; other alternative are Snap, Nix or Homebrew. Flatpak is a good starter, and if you have a bunch of free time, I suggest trying Nix.

- it reduces bloat, because you can generate an environment or OS image with only the software needed to run a specific program or service

My guess is that a big efficiency gain would come from the second point, because you don't waste CPU on code that you don't use.

Does this make sense? Has anyone explored this?

[0]: https://nixos.org

1) Setting up the development environment - I currently use devcontainers for most things, but may also dig into nix -> isolated, portable, repeatable development environment 2) Exploring Echo - understand routing, requests, response, etc. 3) Incorporate Templ - integration with Echo, template composition, etc. 4) Integrating TailwindCSS - config for use with Echo/Templ, development cycle, deployment, etc. 5) Add in HTMX - endpoints, template structure, concepts, etc. 6) hyperscript for interactivity - client side interactivity

"Your greatest challenge lies ahead -- and downwards..."

Oh, wait a second, my bad, that's the quote on the box cover for Zork I: (

https://upload.wikimedia.org/wikipedia/en/a/ac/Zork_I_box_ar...

https://en.wikipedia.org/wiki/Zork

)

What you really wanted was a link to where you could download Nix/NixOS -- and/or learn more about it!

Here ya go!

https://nixos.org/

"Your greatest challenge lies ahead -- and downwards..."

:-) :-)

I say all of the above in the spirit of humor -- and as a NixOS user and fan!

(But yes, there is a learning curve to it, so yes, learning Nix/NixOS could be a challenge!)

((But you're a bright person, you have Google and ChatGPT to assist you, and you like challenges!))