-fn text_of_first_token(node: &SyntaxNode) -> TokenText {
- let first_token =
- node.green().children().next().and_then(|it| it.into_token()).unwrap().to_owned();
+fn _text_of_first_token(node: &SyntaxNode) -> Cow<'_, str> {
+ fn cow_map<F: FnOnce(&GreenNodeData) -> &str>(green: Cow<GreenNodeData>, f: F) -> Cow<str> {
+ match green {
+ Cow::Borrowed(green_ref) => Cow::Borrowed(f(green_ref)),
+ Cow::Owned(green) => Cow::Owned(f(&green).to_owned()),
+ }
+ }
+
+ cow_map(node.green(), |green_ref| {
+ green_ref.children().next().and_then(NodeOrToken::into_token).unwrap().text()
+ })
+}