Implement textDocument/signatureHelp

[bpringe]

This is just a nice to have thing that we currently have in Calva using info from nrepl. See a demo here: https://github.com/BetterThanTomorrow/calva#demo-signature-help-while-typing

[ericdallo]

Available on next release @bpringe :)

But we are not sending the active parameter yet, I think it'd be necessary a clj-kondo analysis change for that.

@borkdude, Would you think it would be possible to add to clj-kondo var-definition analysis some :args field?
For example (defn foo [a b & rest]) would have something like :args ["a" "b" "& rest"].

[borkdude]

@ericdallo We already have :arglist-strs:

$ clojure -M:clj-kondo/dev --config '{:output {:analysis {:arglists true} :format :edn}}' --lint - <<< '(defn foo [a b])' | jet --query ':analysis :var-definitions (map :arglist-strs)'
[["[a b]"]]

[borkdude]

Adding this from a conversation on Slack. If you need the individual args, you can parse it as EDN and ignore the & symbol. This should work for most arglists, except those with auto-resolved keywords. You can work around this using edamame, which already comes with the clj-kondo dependency:

user=> (require '[edamame.core :as e])
nil
user=> (e/parse-string "{::str/keys [:a]}" {:auto-resolve (fn [ns] (symbol (str ":" ns)))})
#::str{:keys [:a]}

[ericdallo]

Done @bpringe, we have full support for textDocument/signatureHelp now :)
Thanks for the help @borkdude, we are using edamame now as you suggested and it seems to work perfectly

[bpringe]

Awesome! Thanks guys.

[gdanov]

this is great, but I can't figure out how to display the signature in pop-up. It does show in the mode line but not in postframe

[ericdallo]

you need to use (setq lsp-signature-posframe 'lsp-signature-posframe)

[gdanov]

this did the job for me

(setq lsp-signature-function 'lsp-signature-posframe)

source:

https://twitter.com/yonchovski/status/1362858080430604292

[ericdallo]

Oh sorry, yes, that is the correct 😅

[gdanov]

no problem ;) just wanted to have it documented for the next one to google it