更新异步step

DoRunner/ExitNamespaceRunner.cs

@@ -1,4 +1,5 @@
 using Convention.RScript.Parser;
+using System.Collections;
 using System.Diagnostics.CodeAnalysis;
 
 namespace Convention.RScript.Runner
@@ -36,5 +37,32 @@ namespace Convention.RScript.Runner
             context.RuntimePointerStack.Pop();
             return null;
         }
+
+        [return: MaybeNull]
+        public IEnumerator RunAsync(ExpressionParser parser, RScriptSentence sentence, RScriptContext context)
+        {
+            // 移除当前命名空间的变量
+            foreach (var local in context.CurrentLocalSpaceVariableNames.Peek())
+            {
+                context.Variables.Remove(local);
+                parser.context.Variables.Remove(local);
+            }
+            // 还原上层命名空间的变量
+            foreach (var local in context.CurrentLocalSpaceVariableNames.Peek())
+            {
+                if (context.Variables.ContainsKey(local))
+                {
+                    parser.context.Variables[local] = context.Variables[local].data;
+                }
+                else
+                {
+                    parser.context.Variables.Remove(local);
+                }
+            }
+            context.CurrentLocalSpaceVariableNames.Pop();
+            // 弹栈
+            context.RuntimePointerStack.Pop();
+            yield break;
+        }
     }
 }