词法分析树增加String()方法

lexical_test.go

@@ -34,9 +34,7 @@ func Test_parseLexical(t *testing.T) {
 }`
 	//jsonData = `{"name":"zhangsan","age":"18","extension":{"sex":"man","height":"180"},"teacher_list":[{"name":"t1","age":"11"},{"name":"t2","age":"12"}]}`
 
-	r, _ := NewLexical(jsonData).Parse(jsonData)
-	for _, val := range r {
-		fmt.Print(val.Val)
-	}
-	fmt.Print("\n")
+	instance := NewLexical(jsonData)
+	_ = instance.Parse()
+	fmt.Println(instance.String())
 }