Add the ability to make multiline suggestions/notes

[RDambrosio016]

Add the ability to make multiline suggestions/notes

[brendanzab]

Yeah, this has been requested before (See #285)! Perhaps this is something we should have a look at.

For this specific instance, I'm wondering if using the notes section would help. Eg.

error: unknown start of token: \u{37e}
  ┌─ main.rs:2:30
  |
2 |    println!("Hello, world!");
  |                             ^
  = Unicode character ';' (Greek Question Mark) looks like ';' (Semicolon), but it is not

But I realise there are other instances where this is not as helpful, say with lifetime diagnostics, where you have to step through a sequence of related locations.

It would also be good to think about how this maps onto the language server protocol, but we might not want to limit ourselves by it. Eg. I tend to find lifetime errors easier to understand in the terminal, rather than using rust-analyzer.

[RDambrosio016]

As with most pretty error stuff, the logic will be lost in the LSP, which is not necessarily bad, i agree with you in saying cli is way better for some errors, i dont think LSP should limit codespan when it comes to features. The example was the first i could think of, it is obviously very simplistic.

[Johann150]

I have not looked at the commits that were made, but maybe #176 could be interesting in this context?

[RDambrosio016]

Allowing users to write their own render logic and plug into codespan's renderer would be infinitely helpful when it comes to more specific diagnostics