CSC/ECE 517 Summer 2008/wiki3 8 jb
This wiki will explore some of Bertrand Meyer's contribution to OO design, including the principles of small interfaces, explicit interfaces, uniform-access, self-documentation, and single-choice. We intend to show good examples of each principle, discuss their support in languages other than Eiffel, and discuss whether it is difficult to follow these principles in certain OO languages.
Background
Principles
Small Interfaces
The principle of small interfaces says, "if any two modules communicate at all, they should exchange as little information as possible" [1]. Following this principle tends to lead to interfaces where native data types are preferred over classes as arguments. This serves to reduce coupling between modules, and reduce the runtime overhead required to pass parameters from caller to callee.
Explicit Interfaces
The principle of explicit interfaces says, "Whenever two modules A and B communicate, this must be obvious from the text of A or B or both" [2].
Uniform-access
The principle of uniform access says, "All services offered by a module should be available through a uniform notation, which does not betray whether they are implemented through storage or through computation."
Self-documentation
The principle of self-documentation says, "The designer of a module should strive to make all information about the module part of the module itself."