Registering methods through scripts/plugins

Hello. Congrats for this awesome project.

Recently I was thinking about doing very specific things using an LSP; Such as word suggestions; Citations suggestions and other features which are not necessarily error checks or obvious fixes.

I know there are specific smalls LSPs which do that. But i would like to have some LSP which could be extended/customizable, such as efm-langserver.

The problem with efm-langserver is it can only register commands for the internal implementation of existing method. You cannot add methods or have new definitions. I cannot post some data besides code to the server, like a prompt, use that to make a request to some server like an inference server, do more processing and send diagnostics back to client.

That is limited, sometimes i want a result which goes beyond getting structured stdout from tool and showing it, like processing and doing something. Sometimes a tool which does what i want does not exist, if this tool manages to process, it would still need to send data back to efm-langserver somehow. There is also the problem emf does not expose variables variables with data which came from the lsp client request payload, only for format-command from what i can see, even though there are also other LSP methods with a lot of fields on the request payload, like completion, hover etc.

So i do not know if you plan to implement that, but there are those challenges.

Last resort would be writting an LSP server.

Start by reviewing efm-langserver's existing script/plugin registration and the handling of LSP request payloads. Compare the current format-command variable support with completion and hover, then clarify the desired extension and data-flow contract before implementation. Done would require an agreed design and tests for registering custom methods and returning processed results.