46. Discussion of Structural Patterns

• In summary,

  • An Adapter change the interface of an existing object.

  • Bridge has a structure similar to an object adapter, but a different intent.

  • Bridge separates an interface from its implementation.

  • Bridge makes possible for the interface and its implementation to vary easily and independently.

  • Decorator enhances object without changing its interface.

  • A decorator is thus more transparent to the application than an adapter is.

  • As a consequence, Decorator supports recursive composition, which isn't possible with pure adapters.

  • Proxy defines a representative (or surrogate) for another object and does not change its interface.