更新异步step

DoRunner/EnterNamespaceRunner.cs

@@ -1,4 +1,5 @@
 using Convention.RScript.Parser;
+using System.Collections;
 using System.Diagnostics.CodeAnalysis;
 
 namespace Convention.RScript.Runner
@@ -24,5 +25,20 @@ namespace Convention.RScript.Runner
             context.RuntimePointerStack.Push(context.CurrentRuntimePointer);
             return null;
         }
+
+        [return: MaybeNull]
+        public IEnumerator RunAsync(ExpressionParser parser, RScriptSentence sentence, RScriptContext context)
+        {
+            // 准备记录当前命名空间中定义的变量, 清空上层命名空间的变量
+            context.CurrentLocalSpaceVariableNames.Push(new());
+            // 更新变量值
+            foreach (var (varName, varValue) in parser.context.Variables)
+            {
+                context.Variables.SetValue(varName, varValue);
+            }
+            // 压栈
+            context.RuntimePointerStack.Push(context.CurrentRuntimePointer);
+            yield break;
+        }
     }
 }