Search results
Results from the WOW.Com Content Network
The Visitor [1] design pattern is one of the twenty-three well-known Gang of Four design patterns that describe how to solve recurring design problems to design flexible and reusable object-oriented software, that is, objects that are easier to implement, change, test, and reuse.
The single-serving visitor pattern should be used when visitors do not need to remain in memory. This is often the case when visiting a hierarchy of objects (such as when the visitor pattern is used together with the composite pattern) to perform a single task on it, for example counting the number of cameras in a 3D scene.
Design Patterns: Elements of Reusable Object-Oriented Software (1994) is a software engineering book describing software design patterns. The book was written by Erich Gamma , Richard Helm , Ralph Johnson , and John Vlissides , with a foreword by Grady Booch .
In software engineering, a software design pattern or design pattern is a general, reusable solution to a commonly occurring problem in many contexts in software design. [1] A design pattern is not a rigid structure that can be transplanted directly into source code. Rather, it is a description or a template for solving a particular type of ...
The visitor pattern works by way of a visitor object visiting the elements of a data structure (e.g. list, tree and so on) polymorphically, applying some action (call or agent) against the polymorphic element objects in the visited target structure.
You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made.
The visitor pattern solves this by factoring out the operation (pretty printing) to a separate class, which specializes in just pretty printing. So if you have many related types, and feel the urge to add more and more operations to (almost) every one of them, consider applying the Visitor pattern. --Objarni 10:57, 9 April 2012 (UTC)
A (software) design pattern is a general solution to a common problem in software design. It is a description or template for how to solve a problem, that can be used in different situations. A design pattern typically shows relationship and interaction between classes or objects, without specifying final application classes or objects that are ...