Richard Eisenberg
Hi devs,
In my work with Alfredo at revising our error message infrastructure, we ran across some code that renders error messages as JSON. Given that our data structures are changing, it seems natural to change the JSON output, too, but it's unclear whether that's wise. The manual currently lists -ddump-json in the chapter on "Debugging the compiler", suggesting that a change is fine, but I'm not yet convinced.
I think it would be fine to change the output. However, note that there is a reason why this flag is in the -d flag namespace and the "Debugging the compiler". The output is quite unstructured and we reserve the right to change the representation, largely because it was hard to do better without first fixing #8809. After we have the new rich errors infrastucture in place I think we will be in a much better place to discuss a properly-supported flag (via the proposal process, presumably). However, I think when we do so we should be careful to constrain the scope of the provided output. GHC is not a language server and I don't think it would be wise to make it one. Cheers, - Ben