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 ()