You could also try for a templating framework (like jinja2) but then you have 3 syntaxes colliding: the programming language you call the templating engine with (e.g. Python for jinja2) the templating language itself (e.g. jinja2) and then JSON as well.
You are not contributing much here. Could you elaborate what problems they were trying to solve and what other problems were met?
Regardless, the reason is exactly what I mentioned, it’s esoteric, specific, and not backed by a community of knowledge.
Here are some of the things I appreciate about Jsonnet:
- It evals to JSON, so even though the semantics of the language are confusing, it is reasonably easy to eval and iterate on some Jsonnet until it emits what one is expecting - and after that, it's easy to create some validation tests so that regressions don't occur.
- It takes advantage of the fact that JSON is a lowest-common-denominator for many data serialization formats. YAML is technically a superset of JSON, so valid JSON is also valid YAML. Proto3 messages have a canonical JSON representation, so JSON can also adhere to protobuf schemas. This covers most "serialized data structure" use-cases I typically encounter (TOML and HCL are outliers, but many tools that accept those also accept equivalent JSON). This means that with a little bit of build-tool duct-taping, Jsonnet can be used to generate configurations for a wide variety of tooling.
- Jsonnet is itself a superset of JSON - so those more willing to write verbose JSON than learn Jsonnet can still write JSON that someone else can import/use elsewhere. Using Jsonnet does not preclude falling back to JSON.
- The tooling works well - installing the Jsonnet VSCode plugin brings in a code formatter that does an excellent job, and rules_jsonnet[0] provides good bazel integration, if that's your thing.
I'm excited about Jsonnet because now as long as other tool authors decide to consume JSON, I can more easily abstract away their verbosity without writing a purpose-built tool (looking at you, Kubernetes) without resorting to text templating (ahem Helm). Jsonnet might just be my "one JSON-generation language to rule them all"!
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Though if Starlark is your thing, do checkout out skycfg[1]
i hate working with SBT. Makes maven pom.xml less cruel in comparision.
Create a framework in a normal language, but one which is very limited by design with regard to what is able to access - Skylark/Starlark is a good example[0], "limited Python" and use that. The rest works the same way, take an input in this language/framework, generate outputs.
[0] - https://bazel.build/rules/language