add show_subtree command for viewing tree-sitter subtree in Popup

[the-mikedavis]

show-subtree.mp4

I have this setup for testing but I'm not sure this command really deserves a default binding in the space+<command> submap:

diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index 49f8469..3050315 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -677,6 +677,7 @@ impl Default for Keymaps {
                 "R" => replace_selections_with_clipboard,
                 "/" => global_search,
                 "k" => hover,
+                "t" => show_subtree,
                 "r" => rename_symbol,
             },
             "z" => { "View"

I kinda just did whatever the rust compiler told me to do, there's probably some wacky stuff in here 😅. In particular the two nested levels of if let Some(...) feel a little clumsy, no? Please feel free to pile on the rust style/nitpick reviews 👍

Also I think it'd be ideal to run the sexp through a pretty printer, but I left that off in this PR.

What do you think?

[the-mikedavis]

oh whoops looks like if you do hover and then show_tree, the contents of the popup overlap. I'll see if I can fix that

edit: it's not particularly elegant but renaming both the docs and subtree Popups to be the same in the compositor fixes that behavior. Maybe I'm abusing that system in the compositor by naming them the same though?

[pickfire]

@the-mikedavis This seemed like something for debugging and not that useful for general users, I guess in cases like this since it is only useful for developers, maybe we should not put it as a normal keymap? But current one should be fine, I don't think it is worth having a key by default for this, but if you want, can keep it commented out or something, maybe note somewhere that this is useful for debugging.

[the-mikedavis]

I think I'll probably rebind it in my config to something like A-t anyways, I'm ok with leaving it out of the keymap even as a comment

[archseer]

Looks good to me 👍🏻

Perhaps it would be useful as a binding though, in case users have highlighting issues with a grammar they'd be able to dump the subtree for including in the bug report?

[the-mikedavis]

I'll make a follow-up PR to hash out a default keybinding 👍