design principle: 优秀程序应该遵循的原则

这篇文章讲解的是关于编程应该遵循的原则。

我只是大致翻译一下，还是细看英文吧，这样才不会被别人误导。

The Principles of Good Programming

by Christopher Diggins

Today's post is a lightly edited repost from my blog at The Area, a web-site dedicated to users of Autodesk
media and entertainment products. I came up with this list of principles to help with a recent C# training I gave, and I thought that members of the Artima.com community could appreciate these principles and have some interesting insights to share.

Principles of Good Programming

The principles of good programming are closely related to principles of good design and engineering. The following programming principles have helped me over the years become a better programmer, and I believe can help any developer become more efficient
and to produce code which is easier to maintain and that has fewer defects.

避免重复原则

DRY - Don’t repeat yourself - This is probably the single most fundamental tenet in programming is to avoid repetition. Many programming constructs exist solely for that purpose (e.g. loops, functions, classes, and more). As soon as you
start repeating yourself (e.g. a long expression, a series of statements, same concept) create a new abstraction.http://en.wikipedia.org/wiki/Don%27t_repeat_yourself

抽象原则

Abstraction Principle - Related to DRY is the abstraction principle “Each significant piece of functionality in a program should be implemented in just one place in the source code.” http://en.wikipedia.org/wiki/Abstraction_principle_(programming)

KiSS原则，保持代码简单

KISS (Keep it simple, stupid!) - Simplicity (and avoiding complexity) should always be a key goal. Simple code takes less time to write, has fewer bugs, and is easier to modify.http://en.wikipedia.org/wiki/KISS_principle

避免创建不必要的功能，避免画蛇添足

Avoid Creating a YAGNI (You aren’t going to need it) - You should try not to add functionality until you need it. http://en.wikipedia.org/wiki/YAGNI

做最简单的事情，简化设计

Do the simplest thing that could possibly work - A good question to ask one’s self when programming is “What is the simplest thing that could possibly work?” This helps keep us on the path towards simplicity in the design. http://c2.com/xp/DoTheSimplestThingThatCouldPossiblyWork.html

保持代码的通俗性

Don’t make me think - This is actually the title of a book by Steve Krug on web usability that is also relevant in programming. The point is that code should be easily read and understood with a minimum of effort required. If code requires
too much thinking from an observer to understand, then it can probably stand to be simplifiedhttp://www.sensible.com/dmmt.html

开闭原则，对修改关闭对扩展开放

Open/Closed Principle - Software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification. In other words, don't write classes that people can modify, write classes that people can extend. http://en.wikipedia.org/wiki/Open_Closed_Principle

保证代码的可维护性

Write Code for the Maintainer - Almost any code that is worth writing is worth maintaining in the future, either by you or by someone else. The future you who has to maintain code often remembers as much of the code, as a complete stranger,
so you might as well always write for someone else. A memorable way to remember this is “Always code as if the person who ends up maintaining your code is a violent psychopath who knows where you live.” http://c2.com/cgi/wiki?CodeForTheMaintainer

最小惊讶原则，不要做出让用户很惊讶的东西比如华丽的界面

Principle of least astonishment - The principle of least astonishment is usually referenced in regards to the user interface, but the same principle applies to written code. Code should surprise the reader as little as possible. The means
following standard conventions, code should do what the comments and name suggest, and potentially surprising side effects should be avoided as much as possible. http://en.wikipedia.org/wiki/Principle_of_least_astonishment

单一责任原则

Single Responsibility Principle - A component of code (e.g. class or function) should perform a single well defined task.http://en.wikipedia.org/wiki/Single_responsibility_principle

低耦合

Minimize Coupling - Any section of code (code block, function, class, etc) should minimize the dependencies on other areas of code. This is achieved by using shared variables as little as possible. “Low coupling is often a sign of a well-structured
computer system and a good design, and when combined with high cohesion, supports the general goals of high readability and maintainability” http://en.wikipedia.org/wiki/Coupling_(computer_programming)

高内聚

Maximize Cohesion - Code that has similar functionality should be found within the same component. http://en.wikipedia.org/wiki/Cohesion_(computer_science)

最大可能的隐藏实现细节

Hide Implementation Details - Hiding implementation details allows change to the implementation of a code component while minimally affecting any other modules that use that component. http://en.wikipedia.org/wiki/Information_Hiding

迪米特法则

Law of Demeter - Code components should only communicate with their direct relations (e.g. classes that they inherit from, objects that they contain, objects passed by argument, etc.) http://en.wikipedia.org/wiki/Law_of_Demeter

避免过早优化代码

Avoid Premature Optimization - Don’t even think about optimization unless your code is working, but slower than you want. Only then should you start thinking about optimizing, and then only with the aid of empirical data. "We should forget
about small efficiencies, say about 97% of the time: premature optimization is the root of all evil" - Donald Knuth.http://en.wikipedia.org/wiki/Program_optimization

代码的可复用性

Code Reuse is Good - Not very pithy, but as good a principle as any other. Reusing code improves code reliability and decrease development time.http://en.wikipedia.org/wiki/Code_reuse

不同领域的功能，应该由不同的代码和最小重迭的模块组成。

Separation of Concerns - Different areas of functionality should be managed by distinct and minimally overlapping modules of code.http://en.wikipedia.org/wiki/Separation_of_concerns

适应改变

Embrace Change - This is the subtitle of a book by Kent Beck, and is also considered a tenet of extreme programming and the agile methodology in general. Many other principles are based on the concept that you should expect and welcome change.
In fact very old software engineering principles like minimizing coupling are related directly to the requirement of making code easier to change. Whether or not you are an extreme programming practitioner, this approach to writing code just makes sense.http://www.amazon.com/gp/product/0321278658