[dmitry-vsl]

I don't have any experience with Jsonnet, but from what I can gather, it appears to be a Turing-complete functional programming language. Leporello.js, on the other hand, is a UX concept that can be applied to any functional programming language, including Jsonnet.

In fact, I believe it's possible to write code in TypeScript that would be very similar to Jsonnet. TypeScript provides the capability to create compiler plugins, which can restrict the allowed language subset, effectively making it more limited and suitable for configuration

[ithkuil]

The main difference between jsonnet and JavaScript/typescript is that it's lazily evaluated.

Evaluation is driven "from the output"; by which I mean that only the code that has an effect on the output is evaluated. When an object is rendered (manifested) all it's non-hidfen fields are evaluated and every expression they contain produces a value which is then manifested and recursively only the fields that are manifested have their expressions evaluated.

This ia particularly important when combined the key operation that jsonnet provides: object overlay/merges. When you overlay an object on another object it may shadow a field of the "super" object causing the expression of the super object to not be evaluated.