暂时实现了简陋的脚本AST分析解释，后面再绑定到控件上

Serein.Script/Node/AssignmentNode.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Serein.Script.Node
+{
+
+    /// <summary>
+    /// 变量节点
+    /// </summary>
+    public class AssignmentNode : ASTNode
+    {
+        public string Variable { get; }
+        public ASTNode Value { get; }
+        public AssignmentNode(string variable, ASTNode value) => (Variable, Value) = (variable, value);
+    }
+
+
+}