1 using System.Collections.Generic;
10 public static IEnumerable<int> Test (Expr expr)
12 object exprCur = expr;
13 if (exprCur is Expr list) {
14 yield return list.Field;
18 public static IEnumerable<string> Test2 (int? expr)
21 while (exprCur != null) {
22 if (exprCur is int list) {
23 yield return list.ToString ();
28 public static void Main ()