Writing a Faster Jsonnet Compiler (2018)

databricks.com

31 points·lihaoyi··8 comments

Not mentioned is the official GoLang version of the Jsonnet compiler. https://github.com/google/go-jsonnet

In my experience the Go version is 10x faster than the original C++ implementation due to improvements. The only thing missing in the Go version is the formatter.

It's mentioned in passing a couple of times, so I assume they've tried it wasn't faster for them.

As someone who is new to configuration-based langages, how is Jsonnet different from Dhall? Do they fill the same niche? Does Jsonnet offer similar guarantee of termination of the config programs like DHall?

unlike DHall, Jsonnet is Turing complete and untyped.

In a way that might make it a bit easier to approach but harder to reason about your configs.

Termination is a red herring, the real problem you want to be worried about is configs that take more CPU / RAM than you have spare. Restricting to primitive recursion does not help there. See https://landing.google.com/sre/workbook/chapters/configurati...

Well it might be fast, but Java/Scala doesn't sound like it is very compact and easy to deploy. It results in a ~10MB jar file + the java runtime.

This can be somewhat mitigated by AOT compilation. Here's a link to some experiments from using SubstrateVM to create a self-contained executable from sjsonnet: https://github.com/databricks/sjsonnet/issues/2

Jsonnet, not Jsonata. Damn, I was excited for a moment there. Well, it was an interesting article anyways.

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