Quotes About Modularity

THE COMMON REUSE PRINCIPLE Don't force users of a component to depend on things they don't need.

If component A should be protected from changes in component B, then component B should depend on component A.

Architects separate functionality based on how, why, and when it changes, and then organize that separated functionality into a hierarchy of components.

But then closely related concepts should not be separated into different files unless you have a very good reason. Indeed, this is one of the reasons that protected variables should be avoided.

One sure way to make a software component difficult to change, is to make lots of other software components depend on it.

A good architecture makes it unnecessary to decide on Rails, or Spring, or Hibernate, or Tomcat, or MySQL, until much later in the project. A good architecture makes it easy to change your mind about those decisions, too. A good architecture emphasizes the use cases and decouples them from peripheral concerns

The business rules should be the most independent and reusable code in the system.

Any comment that forces you to look in another module for the meaning of that comment has failed to communicate to you and is not worth the bits it consumes.

More precisely, the Law of Demeter says that a method f of a class C should only call the methods of these: • C • An object created by f • An object passed as an argument to f • An object held in an instance variable of C

A good architecture protects the majority of the source code from those changes. It leaves the decoupling mode open as an option so that large deployments can use one mode, whereas small deployments can use another.

structured programming, object-orient programming, and functional programming.

Notice how well those three align with the three big concerns of architecture: function, separation of components, and data management.

The standard library saves programmers from having to reinvent the wheel.

An ugly system is one in which there are special interfaces for everything you want to do. Unix is the opposite. It gives you the building blocks that are sufficient for doing everything. That's what having a clean design is all about.

But while you can always write 'spaghetti code' in a procedural language, object-oriented languages used poorly can add meatballs to your spaghetti.

Modularity permits the efficient discrimination of context.

Instead of a single, monolithic system that tried to do everything, Turbulence consisted of nine smaller systems. In part, the various systems served as backups or alternative approaches, in case the others failed or the global technology shifted.

We want to make every single interaction in the world into a ready-to-use brick.

Microkernels are not a pipe dream. They represent proven technology.

Complexity that works is built up out of modules that work perfectly, layered one over the other.

Take what varies and "encapsulate" it so it won't affect the rest of your code.

increase the ease with which innovators can build larger systems from interlinkable modules created by community participants. Free and open source software projects are a relatively well-developed and very successful form of Internet-based innovation community. However, innovation communities are by no means restricted to software or even to

The iPod is a proprietary integrated product, although that is becoming quite modular. You can download your music from Amazon as easily as you can from iTunes. You also see modularity organized around the Android operating system that is growing much faster than the iPhone. So I worry that modularity will do its work on Apple.

To my mind any phenomenon is paracinematic if it shares one element with cinema, e.g., modularity with respect to space and time.