add show_subtree command for viewing tree-sitter subtree in Popup

helix-term/src/commands.rs

@@ -400,6 +400,7 @@ impl MappableCommand {
         decrement, "Decrement",
         record_macro, "Record macro",
         replay_macro, "Replay macro",
+        show_subtree, "Show tree-sitter subtree under primary selection",
     );
 }
 
@@ -6210,3 +6211,33 @@ fn replay_macro(cx: &mut Context) {
         },
     ));
 }
+
+fn show_subtree(cx: &mut Context) {
+    let (view, doc) = current!(cx.editor);
+
+    if let Some(syntax) = doc.syntax() {
+        let primary_selection = doc.selection(view.id).primary();
+        let text = doc.text().slice(..);
+        let from = text.char_to_byte(primary_selection.from());
+        let to = text.char_to_byte(primary_selection.to());
+        if let Some(selected_node) = syntax
+            .tree()
+            .root_node()
+            .descendant_for_byte_range(from, to)
+        {
+            let contents = format!("```tsq\n{}\n```", selected_node.to_sexp());
+
+            cx.callback = Some(Box::new(
+                move |compositor: &mut Compositor, cx: &mut compositor::Context| {
+                    let contents = ui::Markdown::new(contents, cx.editor.syn_loader.clone());
+                    let popup = Popup::new("tree", contents);
+                    if let Some(doc_popup) = compositor.find_id("tree") {
+                        *doc_popup = popup;
+                    } else {
+                        compositor.push(Box::new(popup));
+                    }
+                },
+            ));
+        }
+    }
+}

languages.toml

@@ -377,6 +377,7 @@ scope = "source.tsq"
 file-types = ["scm"]
 roots = []
 comment-token = ";"
+injection-regex = "tsq"
 indent = { tab-width = 2, unit = "  " }
 
 [[language]]