Code style¶

This section explains some general implementational ideas used in various parts of the code. It is dedicated to the users who would like to extend or modify the implemented functionality and/or would like to learn more about the implementation strategies and certain theoretical aspects.

General remarks¶

• The directories and filenames use camelCase.
• The source files and the header files have a cpp and a hh extension, respectively.
• A clang-format file is used, which needs to be executed in each extended or modified file before a PR can be merged.
• Readability and value semantics are the essence of the code.
• Commenting within the code and the other code styles were influenced by the books by Robert C. Martin¹ and John K. Ousterhout².

Separation of interface and implementation¶

The notion of a description of an interface and a discussion of its implementation are found in many pages. The question of what an interface and an implementation mean is answered here with an example of a car.

Interface of a car¶

Let's first define the interface of a car. A car is from a certain brand, and it has a maximum velocity. The car's interface is thus:

• brand(): a function which returns the brand name as a string
• maxvelocity(): a function which returns the maximum velocity as a double

This can be written in a more formalized way, e.g., as a C++20 concept, but we currently write it in this documentation as shown above.

Every object that is then to be declared as a car has to have a member function brand() which returns a string, and a member function maxVeloctiy() which returns a double.

Implementation of a car¶

Let's now implement a car.

class MyCar
{
  public:
  std::string brand() {return "MyBrand";}
  double maxVelocity() 
  {
    double velocity;
    // calculate maximum velocity with some complicated calculations
    return velocity;
  }
};

Thus, the following definitions are summarized: - Interface: Defines a set of requirements - Implementation: A specific class which fulfills the interface