Delimitate regions eligible for spell checking.

A discussion started at neovim about the benefits that LSP could bring to spell checking, but I'm not sure whether this has been discussed here yet.

The LSP server is very aware of the file structure and programming language specificities, which makes it a very good candidate for delimiting regions eligible to spellchecking (comments, docstrings, strings maybe, variable names maybe, etc.).

Could this spellcheck-regions-delimiting activity be part of the protocol? What would it imply in terms of coordination with existing spellcheckers/editors?

The most basic support would be to not delimitate anything and return the whole file as one big region, leaving the burden of ignoring keywords, etc. to the spellchecker itself. Such a trivial implementation is dummy, but it would still be useful in 2 cases I think:

• For a not-a-programming-language-LSP server, dedicated to parse plain, free .txt-like files written in natural language.
• For transient, basic support in other LSP servers, as a temporary solution so they comply to the protocol even though they have not implemented precise region-delimiting logic yet.

Start by reading this issue and the linked Neovim discussion to understand the proposed spell-checking regions and coordination concerns. Define the protocol requirements and affected specification sections before implementation; done requires an agreed design rather than an isolated code change.