实现访问者模式示例，添加形状、访问者及具体实现，增强代码可读性

ts/src/visitor/index.ts

@@ -0,0 +1,67 @@
+/*
+实例：
+汤宝宝坚信搭积木是人类的未来，因此开办了一家积木厂。
+*/
+
+// 抽象Node接口 Shape
+interface Shape {
+  accept(visitor: Visitor): void;
+  claimShape(): string;
+}
+
+class Circle implements Shape {
+  accept(visitor: Visitor): void {
+    visitor.visitCircle(this);
+  }
+  claimShape(): string {
+    return "I am a Circle";
+  }
+}
+
+class Square implements Shape {
+  accept(visitor: Visitor): void {
+    visitor.visitSquare(this);
+  }
+  claimShape(): string {
+    return "I am a Square";
+  }
+}
+
+class Triangle implements Shape {
+  accept(visitor: Visitor): void {
+    visitor.visitTriangle(this);
+  }
+  claimShape(): string {
+    return "I am a Triangle";
+  }
+}
+
+// 抽象Visitor接口
+interface Visitor {
+  visitCircle(circle: Circle): void;
+  visitSquare(square: Square): void;
+  visitTriangle(triangle: Triangle): void;
+}
+
+class ShapeVisitor implements Visitor {
+  visitCircle(circle: Circle): void {
+    console.log("Visiting Circle: ", circle.claimShape());
+  }
+  visitSquare(square: Square): void {
+    console.log("Visiting Square: ", square.claimShape());
+  }
+  visitTriangle(triangle: Triangle): void {
+    console.log("Visiting Triangle: ", triangle.claimShape());
+  }
+}
+
+(function () {
+  console.log("========== 访问者模式 ==========");
+  const shapes: Shape[] = [new Circle(), new Square(), new Triangle()];
+  const visitor: Visitor = new ShapeVisitor();
+
+  shapes.forEach((shape) => {
+    shape.accept(visitor);
+  });
+  console.log("\n======== 访问者模式结束 ========");
+})();