refactor(empty_list_concat): let-else and try-expression

lib/src/lints/empty_list_concat.rs

···
 
 impl Rule for EmptyListConcat {
     fn validate(&self, node: &SyntaxElement, _sess: &SessionInfo) -> Option<Report> {
-        if let NodeOrToken::Node(node) = node
-            && let Some(bin_expr) = BinOp::cast(node.clone())
-            && let Some(lhs) = bin_expr.lhs()
-            && let Some(rhs) = bin_expr.rhs()
-            && let Some(op) = bin_expr.operator()
-            && let BinOpKind::Concat = op
-        {
-            let at = node.text_range();
-            let message = "Concatenation with the empty list, `[]`, is a no-op";
-            if is_empty_array(&lhs) {
-                Some(self.report().suggest(at, message, Suggestion::new(at, rhs)))
-            } else if is_empty_array(&rhs) {
-                Some(self.report().suggest(at, message, Suggestion::new(at, lhs)))
-            } else {
-                None
-            }
+        let NodeOrToken::Node(node) = node else {
+            return None;
+        };
+
+        let bin_expr = BinOp::cast(node.clone())?;
+        let lhs = bin_expr.lhs()?;
+        let rhs = bin_expr.rhs()?;
+        let Some(BinOpKind::Concat) = bin_expr.operator() else {
+            return None;
+        };
+
+        let at = node.text_range();
+        let message = "Concatenation with the empty list, `[]`, is a no-op";
+        if is_empty_array(&lhs) {
+            Some(self.report().suggest(at, message, Suggestion::new(at, rhs)))
+        } else if is_empty_array(&rhs) {
+            Some(self.report().suggest(at, message, Suggestion::new(at, lhs)))
         } else {
             None
         }