Companion DAP package

[cyruseuros]

To the best of my knowledge, the DAP ofter relies on information from the LSP for the same language, so it would make sense to have an eglot companion package to achieve this interop.

[cyruseuros]

Note that I'm raising this issue in light of this response on the dap-mode repo, and the fact that the existence of dap-mode seems to be enough of a reason for realgud to not implement this feature. Nothing against these projects, people are not obliged to volunteer their time, but if Eglot ends up in Emacs core it would be good to have core module implementing the DAP as well.

[joaotavora]

Yes, I think this is a nice idea.

But it should not be a part of Eglot, rather its own package.

The jsonrpc.el package (that is already in Emacs core), is probably quite useful for developing such a package, since as far as I can tell it's a JSONRPC protocol as well. As probably would be many LSP-agnostic functions and utilities that currently live in eglot.el.

You can make that future gudap.el (name idea) package depend on eglot.el (as a library) for those utilities. Or, better yet, or extract them into jsonrpc.el, so that gudap.el depends only on them.

I would also reuse as much of gud.el as possible, and add to it when the needed functionality isn't there yet.