dnjs VS jsonnet

How about just nudge json a couple more notches towards js? https://github.com/leontrolski/dnjs

I've been reading the book Modern Compiler Implementation in ML lately. It's been helpful to brush up on some concepts while developing Tsonnet (my typed-aspiring Jsonnet flavor) and I hope to learn a ton more. However, I'm growing dissatisfied with some details -- not specifically the book, but the choice of the development environment.

For the past 2 years, I've been working extensively with Jsonnet, a configuration language that augments JSON and helps eliminate repetition in our config files. It has its limits (many by design), which keeps the language simple to use. But there's one thing that keeps nagging at me when I'm deep in the code: what's the shape of the input or output of this function? And wouldn't it be great if we could type objects and completely ditch those validators checking value types? Having a compiler handle all that would be sweet. I'm not alone here – I've talked to plenty of folks who'd love this feature too.

Kubernetes does not provide or require a configuration language like Jsonnet, as it provides a declarative API that can be used with different types of declarative specifications.

jsonnet[1] and kapitan[2] are the tools I currently use. Their learning curve is not optimal (and I tried to contribute to smoothen it with a jsonnet course[3] and a 'get started wit kapitan' blog post[4]), but once used to it it's hard to do without, and their combination makes them even more useful (esp. if you deploy K8s).

In Ruud's case, Jsonnet might have been worth looking at as Hashicorp tools can be configured with json in addition to HCL. But that would have been less fun I guess ;-)

I hope for Ruud it finds its niche, there's quite some competition in this field!

1: https://jsonnet.org/

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)

jsonnet cli: link

Jsonnet: A data template language implemented in C++, suitable for application and tool developers, can generate configuration data and organize, simplify and manage large configurations without side effects.

[Language: Jsonnet] (on GitHub)

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