Visitor Pattern

The visitor pattern is a simple technique to process arbitrary data structures .

访问者模式是一种处理任意数据结构的简单技术。

Another aspect of the Visitor pattern not closely examined here is iteration order .

就访问者模式而言，本文未加详述的另一各方面就是迭代顺序。

The question is , can we implement the Visitor pattern without recursion ?

问题在于，我们能否在不使用递归的前提下实现访问者模式？

Thus , in Jam , the visitor pattern can 't be used with mixins .

因此，在Jam中，访问者模式不能和mixin一起使用。

As a first step , we can think back to our Java language implementation of the Visitor pattern and try something similar .

第一步，我们可以回顾访问者模式的Java语言实现，并尝试进行类似的实现。

In each case , I 've found that the Visitor pattern is a reliable tool for manipulating trees of data .

无论使用哪种语言，访问者模式都是操作树形数据的一种可靠工具。

All bytecode scanning detectors are based on the visitor pattern , which FindBugs implements .

所有字节码扫描检测器都基于visitor模式，FindBugs实现了这个模式。

The Visitor pattern creates a scenario where adding operations ( new visitors ) over the set of existing data types is easy .

访问者模式将创建一个场景，简化对现有数据类型集合添加操作（新访问者）的过程。

To perform queries on the AST parse tree , the Java IDE uses a visitor pattern .

要在AST剖析树上执行查询，JavaIDE使用了一个访问者模式。

Consider the visitor pattern in which a visitor class is defined with a for method for each class in a composite hierarchy .

请考虑访问者模式，其中用for方法为复合层次结构中的每个类都定义了访问者类。

In particular , I 've found that integrating functional zippers into the Visitor pattern yields efficiency benefits , which I explore .

具体来说，我发现将函数式zippers集成到访问者模式之中会带来效率方面的优势，我将对此加以讨论。

Like the JDT , the CDT DOM uses a visitor pattern to interact with its parse tree .

类似于JDT，CDTDOM使用一个访问者模板，以和它的剖析树状图交流。

The Visitor pattern is often used to separate a data structure ( the tree , in this case ) from the algorithms that operate over the data structure .

访问者模式往往用于将数据结构（本例中是树）与通过数据结构操作的算法分离开来。

Adding new data types ( classes ) with visitors is difficult , however , as the Visitor pattern requires a visit () method for all concrete types .

然而，通过访问者添加新数据类型（类）较为困难，因为访问者模式要求所有具体类型都具有一个visit（）方法。

Curried closures can be used to mimic the essential elements of the Visitor pattern , as we showed in the Library example .

Curry过的闭包可以用来模拟Visitor模式的基本元素，正如在Library例子中显示的。

Jomo Fisher demonstrates a visitor pattern than will walk an expression tree , creating a new tree while swapping out specific nodes .

JomoFisher演示了一个使用访问者模式代码，这段代码通过创建一个新树来替换特定的节点，而不是浏览整个表达式树。

In this article , I revisit domain trees and the Visitor pattern for the Java language , then walk through several visitor implementations using Clojure .

在这篇文章中，我回顾了域树（domaintrees）和Java语言的访问者模式，随后介绍了使用Clojure的几种访问者实现。

Leveraging Clojure 's functional programming tools to implement the Visitor pattern is one way to get around this incidental complexity , while still programming on the JVM .

利用Clojure的函数式编程工具来实现访问者模式是消除这种附带的复杂性的一种方法，而且仍然是在JVM上编程。

This article has just scratched the surface of using zippers in the Visitor pattern ; the point of it is to whet your appetite for further exploration .

这篇文章仅仅是涉及了在访问者模式中使用zippers的一些浅显问题；目的在于激发您进一步探索的兴趣。

In the visitor pattern , the calling method ( the builder , in this case ) implements a visitor interface ( the specific interface to implement is IResourceDeltaVisitor ) .

在访问者模式中，调用方法（这里是builder）实现了访问者接口（要实现的特定接口是IResourceDeltaVisitor）。

Another design pattern that lends itself well to DEBA is the Visitor pattern , which externalizes an operation that will be performed on another object , a group of objects , or a structure of objects .

另外一种可用于DEBA架构的设计模式是Visitor（访问者）模式，将操作外部化，可以对其他对象、对象组或者对象结构执行这些操作。

Visitor Design Pattern Applied to GIS Element Drawing

Visitor模式在GIS要素绘制中的应用

Visitor design pattern in software refactoring and application

软件重构中Visitor设计模式和应用

The Visitor design pattern is used to separate the exception hierarchy from the code that builds the fault details .

Visitor设计模式用于把异常层次与构建故障详细信息的代码分开。

In the light of the object-oriented design principles , Visitor design pattern and its improved pattern are presented and analyzed . Then a new patter & reflect visitor pattern is put forward .

在面向对象设计理论指导下，通过分析Visitor设计模式及其已有改进模式的组成及其优缺点，提出了基于反射机制的改进方案ReflectVisitor模式。

We discuss GIS element drawing , and by com-paring all the methods , in proper sequence we give the process of adopting the Visitor design pattern as our final method . We show the advantages that visitor pattern bring us .

该文探讨了GIS中地理要素的绘制，通过对各种方法的对比，循序渐进地论述了Visitor模式作为最终设计方案的过程，并且说明了使用这种设计模式的所带来的好处。

Based on the visitor design pattern , the spatial index interface is designed . The spatial index module is implemented using the R-tree data structure and algorithms . And based on the adapter design pattern , index structure and spatial data are accessed and persisted in the relational table .

采用访问者设计模式设计了空间索引接口，基于R-tree的数据结构与算法实现了空间索引，基于适配器设计模式实现了对空间数据的一体化存储。

This serves as a useful base case , similar to a base Visitor class in the classic Visitor pattern .

这将作为一种有用的基本用例，类似于经典访问者模式中的基本Visitor类。