Question

What is the self-documentation principle? How does Eiffel support this principle?

Answer 1

The self-documentation principle, also known as Design by Contract, focuses on documenting the behavior and expectations of software components. Eiffel supports this principle through its built-in support for Design by Contract.

Step-by-step explanation:

The self-documentation principle, also known as Design by Contract, is a software development principle that focuses on documenting the behavior and expectations of software components. It involves specifying preconditions, postconditions, and invariants for each software component. By doing so, the code becomes more self-explanatory and easier to understand.

Eiffel is a programming language that supports the self-documentation principle through its built-in support for Design by Contract. In Eiffel, you can define preconditions, postconditions, and invariants for classes and methods using assertions. These assertions act as contracts, specifying the expected behavior and constraints of the software components.

For example, in Eiffel, you can define a method that calculates the square root of a positive number with the precondition that the input value must be greater than or equal to zero. The method will only be called if the precondition is satisfied, and if not, an assertion failure will occur. This allows programmers to clearly understand the behavior and requirements of the code without needing to read extensive documentation.

Answer 2

The self-documentation principle suggests that code should be self-explanatory and reduce the need for external documentation. Eiffel supports this principle through meaningful naming, contracts, and class invariants.

Step-by-step explanation:

The self-documentation principle is a software engineering principle that suggests that the code should be self-explanatory and should provide clear and concise documentation so that it can be easily understood by other developers. It is based on the idea that the code should be readable like a document, reducing the need for external documentation.

Eiffel, a programming language developed by Bertrand Meyer, supports the self-documentation principle through various features. Eiffel allows the use of meaningful and descriptive naming conventions, making the code more readable. It also encourages the use of contracts, preconditions, and postconditions, which serve as documentation for the methods and ensure that they are used correctly.

Additionally, Eiffel supports class invariants, which are conditions that must hold true before and after each method execution. These invariants act as both documentation and runtime checks, ensuring that the class behaves as intended.