Programming patterns

From GPWiki

Behavioral patterns

• Observer When an object changes state, other objects are notified
• State Changing object behavior depending on the state of an object
• Strategy Supplying different interchangeable variants of an algorithm in a class
• Template method Supplying an algorithm in which sub-classes can redefine certain steps without changing the overall algorithm
• Visitor Separating operations on an object from the object itself in an extendable way. The basis for "double dispatch".

Creational patterns

• Singleton Implementing a class that has exactly one instance and a global point of access
• Abstract Factory Provide an interface for creating families of related or dependent objects without specifying their concrete classes.
• Builder Implementing a class that builds parts of a complex object.

Structural patterns

• Composite Combining several objects into an object that has the same behavior as its parts