Variable Eldoc line count

[Tiv0w]

I've stumbled upon a minor inconvenience in regard to the way eldoc displays the document/onHover text.
Currently, there is a choice between showing 1 line and showing the entire text via lsp-eldoc-render-all.

Metals (the language server for Scala) sometimes shows the signature on one line, and at other times it's a fully formatted Markdown text, having as first line Expression type:.

Here as one line:

Here as formatted text:

I don't really like the minibuffer taking so much space to display hover, I prefer just having the signature, and when I need more documentation, calling lsp-ui-doc-glance.

So, I have tweaked the lsp-clients-extract-signature-on-hover to show a user-defined number of lines. Somewhat following #2613, this could be a way to accommodate to the format imposed by the LSP (if it's non-"standard"), effectively letting users tweak "on-the-fly" the quantity of information given by eldoc.

(use-package lsp-metals
  :after (scala-mode lsp-mode)
  :config
  (setq-local lsp-eldoc-render-lines-count 2))

Would this change be appreciated in lsp-mode? (I can submit a PR.)

Many thanks to everyone involved in the project for this great suite of packages.

[yyoncho]

So, I have tweaked the lsp-clients-extract-signature-on-hover

Technically, lsp-clients-extract-signature-on-hover is extension point. You can write something like:

(cl-defmethod lsp-clients-extract-signature-on-hover (contents (_server-id (eql metals)))
 ;; the logic you like goes here
 )

Let me think for some time whether we want to have that configurable for on hover. We have such a configuration for signature help.

[Tiv0w]

Since yesterday I did exactly that, I changed lsp-clients-extract-signature-on-hover to filter some lines I don't want to show via regexp (namely the infamous Expression type: line from Metals).

But I don't really if it's that much necessary (nor wanted) to expose such behavior to the user of the lsp-mode, since the tinkerers will tinker, and it will probably add maintenance work.