
	Where results make sense

Topic: Hierarchical visitor pattern

Related Topics

Facade pattern

Composite pattern

Tree data structure

Factory method pattern

Prototype pattern

Builder pattern

Decorator pattern

Iterator pattern

In the News (Tue 22 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Visitor pattern - Wikipedia, the free encyclopedia
		Thus the visitor pattern simulates double dispatch in a conventional single-dispatch object-oriented language such as Java, Smalltalk, and C++.
		Because the Visitor object has one principal function (manifested in a plurality of specialized methods) and that function is called visit(), the Visitor can be readily identified as a potential function object or functor.
		That is the purpose of the Visitor pattern: to separate an algorithm (the function) from some multi-component object (a syntax tree, list, hash, automobile with parts, etc).
	en.wikipedia.org /wiki/Visitor_pattern (1611 words)

	61summary.html (Site not responding. Last check: 2007-09-11)
		State pattern does not have a constant to specify which state the program is in, rather than it makes change clear by copying one of the states to the state variable.
		The Visitor pattern represents an operation to be performed on the elements of an object structure, without changing the classes on which it operates.
		Visitors are not very helpful during a program's growth stage, because each time you add new classes which must be visited, you have to add an abstract visit operation to the abstract visitor class and you must add an implementation for that class to each concrete visitors you have created.
	sern.ucalgary.ca /~grai/seng/609.04/PatternSummaries.html (2710 words)

	A Pattern Language for Pattern Writing (Site not responding. Last check: 2007-09-11)
		As the patterns community has accumulated experience in writing and reviewing patterns and pattern languages, we have begun to develop insight into pattern-writing techniques and approaches that have been observed to be particularly effective at addressing certain recurring problems.
		It is not the primary purpose of this pattern language to define the concept of a pattern or a pattern language.
		Pattern writers can put a lot of effort into describing their patterns but all this effort is for naught if the reader cannot understand it or gives up out of frustration.
	webclass.cqu.edu.au /Patterns/Resources/writers/language/patterns.html (11909 words)

	Citations: The essence of the Visitor pattern - Palsberg, Jay (ResearchIndex)
		For instance, we present three extensions of the visitor pattern technique: v1 using re exivity mechanism with pro led visits and tree traversal possibilities, v2 adding simple aspect oriented programming, v3 splitting the tree traversal (visit method calls) and the semantic actions by using....
		Kuhne s Translator pattern relies on generic functions performing a double dispatch on the given operation and datatype variant [18] As with the solution of Krishnamurthi, Felleisen and Friedman, datatype extensions always entail adaptions of existing....
		The visit and accept methods are necessary because using visitors is essentially using dynamic double dispatch the correct method is selected based on both the acceptor s class and the visitor s class.
	citeseer.ist.psu.edu /context/43557/60122 (2483 words)

	Pattern Discussions
		The Singleton pattern is often paired with the Abstract Factory pattern.
		For non-creational pattern, Façade may be used with Singleton pattern in case one single instance of interface to a set of interfaces in the subsystem is needed.
		One possible approach would be to divide the mediator into a set of mediators such that we may group the communication among objects in a hierarchical structure.
	www.cs.unc.edu /~jeong/204/Patterns (3084 words)

	Experience in the Applying Design Patterns
		The intent of the Interpreter pattern is to represent the grammar of a language and interpret sentences in the language (Gamma, Helm, Johnson, and Vlissides, 1994, pp 243-255).
		The Visitor pattern represents an operation to be performed on the elements of a class structure (Gamma, Helm, Johnson, and Vlissides, 1994, pp 331-344).
		In DESIRE, hierarchical relations between sorts are allowed; the sub-sort-relation is one of the many relations that may exist between sorts in a domain.
	ksi.cpsc.ucalgary.ca /KAW/KAW98/jonker (5288 words)

	Patterns for Java and Distributed Computing
		The purpose of the state pattern is not to mimic the behavior of state-machines, it is to allow an object to appear to alter its behavior-type at run-time.
		The problem that Visitor solves is one in which the particular implementation to use may vary depending on the class of two arguments instead of just one: the class of operation to be performed, and the class of the object to operate on.
		The second-half of the polymorphic handshake is that single-dispatch based on the class of the Visitor operation is performed by the acceptVisitor method invoking the visitTypeX method of the Visitor object, and passing itself as an argument to the visitor (where TypeX is the name of the class of object being visited).
	www.cmcrossroads.com /bradapp/javapats.html (11272 words)

	Encapsulation, Inheritance and the Platypus effect
		The Visitor pattern is a kludge to get that effect for two arguments, but there's no way to do it for more than two.
		In C++ classes serve multiple purposes: they represent the type of a data storage, they are the unit of abstraction, the unit of access control, and they are a container for the methods declared on that object.
		He invented pattern languages in the hope of replicating some of the extraordinary qualities of some vernacular architecture; there are strong parallels between his thinking and the theories of open-source quality erected by Eric Raymond.
	www.advogato.org /article/83.html (7595 words)

	State Programming Language (Site not responding. Last check: 2007-09-11)
		Hierarchical, type parametrized systems, controlled by Moore statemachines, are connected with arbitrary precision signals.
		This is an attempt to do something good for the poor automation industry where ladder diagrams are the standard programming language.
		It is also a personal education project in language design, the Visitor pattern and code generation.
	state.sourceforge.net (78 words)

	LtU Classic Archives
		Visitor and Observer patterns become a whole lot less cumbersome; and (3).
		I guess one could make the case that the Visitor pattern does have problems related to breaking the abstraction.
		Indeed, languages like Goo and Dylan (not to mention CLOS) are also related in their concept of multi-method delegation where new methods and properties can be added to change the type represented by a class (with type here defined in terms of state and behavior of an object).
	lambda-the-ultimate.org /classic/message3189.html (2758 words)

	Class PTTestVisitor (Site not responding. Last check: 2007-09-11)
		Traverses a Composite of tests, following the cgiwiki?HierarchicalVisitorPattern">Hierarchical Visitor pattern.
		It is an extension of the traditional Visitor pattern that keeps track of depth and allows branches of the tree to be skipped.
		Each suite may itself be the child of another suite.
	homepage.mac.com /jon_n_kay/progtest/objcdoc/PTTestVisitor.html (51 words)

	Tandem Architecture
		Tandem's architrecture places a strong emphasis on the use of design patterns both in documenting the framework and in solving key design issues.
		This design is similar to the Broker pattern, particularily with respect to the client and client proxy as well as the server and server proxy, since these classes can be used in both client and server applications.
		These components are modelled after the visitor pattern and are designed to extend the behavior of the Tandem Graphics Component hierarchy.
	www.evl.uic.edu /cavern/seminars/limbo2/tandemArch.html (1286 words)

	ASPN : Python Cookbook : Pickle Python Objects to a DOM tree and vice versa (Site not responding. Last check: 2007-09-11)
		This receipe provides lightweight functions for pickling objects to a DOM structure and vice versa.
		I use it in connection with Hierarchical Objecs from receipe #286150.
		It shows how to implement the visitor pattern in Python.
	aspn.activestate.com /ASPN/Cookbook/Python/Recipe/355487 (291 words)

	Design Patterns
		The Chain of Responsibility pattern's pitfalls and improvements
		A J2EE presentation pattern: Applets with servlets and XML
		E++: A pattern language for J2EE applications, Part 2
	www.javaworld.com /channel_content/jw-patterns-index.shtml (1078 words)

Try your search on: Qwika (all wikis)