Federico Mena-Quintero
federico@gnome.org 2013
Miguel de Icaza
miguel@gnome.org
Morten Welinder
mortenw@gnome.org

This work is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.

As a special exception, the copyright holders give you permission to copy, modify, and distribute the example code contained in this document under the terms of your choosing, without restriction.

Good, readable code keeps the project maintainable
Ελληνική μεταφραστική ομάδα GNOME
team@gnome.gr 2016
Θάνος Τρυφωνίδης
tomtryf@gnome.org 2016

# The Importance of Writing Good Code

GNOME is a very ambitious free software project, and it is composed of many software packages that are more or less independent of each other. A lot of the work in GNOME is done by volunteers: although there are many people working on GNOME full-time or part-time for here, volunteers still make up a large percentage of our contributors. Programmers may come and go at any time and they will be able to dedicate different amounts of time to the GNOME project. People’s “real world” responsibilities may change, and this will be reflected in the amount of time that they can devote to GNOME.

Software development takes long amounts of time and painstaking effort. This is why most part-time volunteers cannot start big projects by themselves; it is much easier and more rewarding to contribute to existing projects, as this yields results that are immediately visible and usable.

Thus, we conclude that it is very important for existing projects to make it as easy as possible for people to contribute to them. One way of doing this is by making sure that programs are easy to read, understand, modify, and maintain.

Messy code is hard to read, and people may lose interest if they cannot decipher what the code tries to do. Also, it is important that programmers be able to understand the code quickly so that they can start contributing with bug fixes and enhancements in a short amount of time. Source code is a form of communication, and it is more for people than for computers. Just as someone would not like to read a novel with spelling errors, bad grammar, and sloppy punctuation, programmers should strive to write good code that is easy to understand and modify by others.

The following are some important qualities of good code:

# Cleanliness

Clean code is easy to read with minimum effort. This lets people start to understand it easily. This includes the coding style itself (brace placement, indentation, variable names), and the actual control flow of the code.

# Συνοχή

Consistent code makes it easy for people to understand how a program works. When reading consistent code, one subconsciously forms a number of assumptions and expectations about how the code works, so it is easier and safer to make modifications to it. Code that looks the same in two places should work the same, too.

# Επεκτασιμότητα

General-purpose code is easier to reuse and modify than very specific code with lots of hardcoded assumptions. When someone wants to add a new feature to a program, it will obviously be easier to do so if the code was designed to be extensible from the beginning. Code that was not written this way may lead people into having to implement ugly hacks to add features.

# Correctness

Finally, code that is designed to be correct lets people spend less time worrying about bugs, and more time enhancing the features of a program. Users also appreciate correct code, since nobody likes software that crashes. Code that is written for correctness and safety (i.e. code that explicitly tries to ensure that the program remains in a consistent state) prevents many kinds of silly bugs.

# Αναφορές βιβλίων

Code Complete, από Steve McConnell.

Refactoring: Improving the Design of Existing Code , από Martin Fowler.

Design Patterns: Elements of Reusable Object-Oriented Software , by Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides.

Object-Oriented Design Heuristics , από Arthur Riel.