Normalised results output about catala

[AltGr]

Some more insights related to JSON output — but not to the tests actually:

We want to (and already do) output reusable traces of programs when compiled with --trace ; we already have a printer for them based on JSON that is used for the French benefits visualisation interface. And these traces do include embedded runtime values, which we already have a printer for in the OCaml / JS backend!

So the question could actually be, do we want to extend this trace printing to the other backends, and do we want to make it more accessible or not (e.g. to print computation results) ?
See also my suggestion of using ATD to have a shared definition of this format across backends.

[pierregoutagny]

I think it could be quite useful to me to have a normalised output format. However, because I generate input structures as well as output structures, I'm wondering if it would be possible for runtimes to also take input structures as input. Do you think it would be easier for runtimes to take input JSONs or for me to output valid surface language code ?

[AltGr]

Definitely we don't want to include a parser in the runtime, which would be much more complex, and doesn't fit with the use-cases we target: catala programs are expected to be run natively as libraries, rather than providing APIs.

Of course, for final needs, one can easily build an API server around the core computation done by Catala; but that should be left to the application as it certainly will need to be specialised for the use-case. We might provide tools for that, but it shouldn't be part of the runtime.

We are actually discussing, for the same reasons, the relevance of JSON output (although most of this discussion was offline), and were leaning against it, but the need for traces might affect the decision.

[AltGr]

I think #585 supersedes this, so closing now.