Programming As Information Architecture
Code = Information. [1] Therefore, Software Architecture can be approached as Information Architecture. Information Architecture can be defined as
- The structural design of shared information environments.
- The art and science of shaping information products.
The above definitions and much of the inspiration for this article comes from the book Information Architecture for the World Wide Web. My goal is to explain some of what an Information Architect does, and that software developers, especially the lead developer, should approach their code as an information system, applying the principles of Information Architecture. Why? Because it will lead to more organized, better structured, easier to understand code, which will reduce maintenance costs, decrease training time, and generally make it easier for you and your team to get things done.
So, what are the core focus areas for an Information Architect?
- Organization Systems
- Labeling Systems
- Navigation and Search Systems
- Controlled Vocabularies and Metadata
- Research
- Strategy
- Design and Documentation
Organization Systems
Organization Systems are exactly what you think they are: systems to organize information. Imagine if you had to come into your current code base completely fresh, knowing nothing about it. Does that thought horrify you? If your code isn’t organized, then it can be very hard for new developers to come in and figure out what’s going on. Think of your code repository as a shared information environment. If you are the only one that can navigate it, let alone modify it, then you’ll always be stuck maintaining it. Hopefully your goal is not job security, but to provide an environment conducive to change.
So how should you organize your code? Unfortunately, that’s not something that’s really taught anywhere. My general practice is to follow the recommendations of the language/platform. If they say all code should go in a directory called src/, then that’s where I put it. If every class is supposed to be in its own file, then that’s what I do. And if the platform documentation doesn’t specify how to do something, I’ll find a major open source project and see how they do things. The key to an organization system is to maintain logical consistency. Then, as long as you know the logic, you can figure out where things are or where something should go.
Labeling Systems
Labeling Systems are basically standard naming practices. In IA, a labeling system specifies what label goes with each element in every context. For programming, you’ll want a consistent naming scheme to make sure the all your code objects are consistently and clearly labeled. Good labels are simple, make sense in context, and hint at the details of the labeled object. The goal is to communicate information efficiently. You are not just writing code for yourself, you’re writing code for the team. The best code is not only functional, it’s readable, concise, and even beautiful. Clear labeling goes a long way towards achieving that ideal.
Navigation and Search Systems
Navigation and Search Systems are very important to information focused websites, but they don’t apply much to code by itself. However, good Navigation and Search Systems are essential for API documentation. I believe that the quality of the API documentation has a huge effect on the adoption rate of libraries and platforms. [2] Good API docs can be great resource for quickly looking up a function and understanding how to use it. But if a developer can’t navigate and search your API documentation, then how will they figure out how to that function works? Luckily for us programmers, navigation is usually provided for free with a documentation generator. And google can handle the search for you.
Controlled Vocabularies and Metadata
While all programming languages have a controlled vocabulary, in IA this refers to domain knowledge. The principle is to use words and jargon that are common to whatever domain you are developing for.
Metadata, in this case, is information about the code, such as comments and documentation. Just as an Information Architect is in charge of the language use within a system, the lead developer should be in charge of the domain language and how to use it.
Research
The goal of IA Research is to understand what needs to be designed and built before doing the work. In programming, you are often presented with problems you’ve never solved before. Hacking, or exploratory programming, is a way to figure out and evaluate possible solutions. Hacking is Research. The goal of research oriented hacking is to figure out possible solutions, evaluate platforms and technologies, and understand the constraints that come with each technology and solution. The knowledge you gather from research is used to drive your strategic choices.
Strategy
IA Strategy is about platform, process and design. What programming language(s) will you use? What are the core design patterns and architectural choices? What version control system will the team use? How will you track progress? Your strategic decisions will set the design constraints of the implementation and drive the development process.
Design and Documentation
In software development, the code is the design, but not everyone will want to read your code to understand how things work. You may need to communicate the design in other ways, such as with diagrams, comments, and documentation. And if the code is being written by someone else, then it’s your job to communicate how their code will fit in to the rest of the system. Design documents aren’t for you, they’re for the other people on the team. You do want other team members to understand your code, right? And if your diagrams and documentation are good enough, you might even get business people to think they understand your software too 
Conclusion
Information Architecture provides a top-down view of your software system. As a lead developer or software architect, IA principles and practices can help make sure that your system is well designed and that the design is communicated clearly to all team members. For further reading, I recommend Information Architecture for the World Wide Web and Documenting Software Architectures.
Notes
[1] Code = Data, Data = Information, Code = Information.
[2] I wish I had some data to back this up, but it’s certainly how I behave. Lack of clear documentation = fail.
Static Analysis of Erlang Code with Dialyzer
Dialyzer is a tool that does static analysis of your erlang code. It’s great for identifying type errors and unreachable code. Here’s how to use it from the command line.
dialyzer -r PATH/TO/APP -I PATH/TO/INCLUDE
Pretty simple! PATH/TO/APP should be an erlang application directory containing your ebin/ and/or src/ directories. PATH/TO/INCLUDE should be a path to a directory that contains any .hrl files that need to be included. The -I is optional if you have no include files. You can have as many -r and -I options as you need. If you add -q, then dialyzer runs more quietly, succeeding silently or reporting any errors found.
If you have a test/ directory with Common Test suites, then you’ll want to add “-I /usr/lib/erlang/lib/test_server*/include/” and “-I /usr/lib/erlang/lib/common_test*/include/”. I’ve actually set this up in my Makefile to run as make check. It’s been great for catching bad return types, misspellings, and wrong function parameters.
Programming as Design
Some say programming is engineering, others call it an art. A few might (mistakenly) think it’s a science. But both the art and engineering can be encapsulated under the umbrella of design. The best design is functional art, and a huge part of the artistic beauty of a product is a result of carefully engineered functionality. Products that are not carefully designed and engineered generally suck to use, and that applies to everything from cameras to software APIs.
Design Principles
There are 4 major principles of graphic design.
Alignment
The principle of alignment is that everything on a page should be connected to something else on the page. The goal of alignment in graphic design is to create visual associations, often using a grid based layout. In software, we can apply this principle to the connectedness of data, such as the object inheritance hierarchy and relational data structures. Ideally, all your objects fit nicely into a well-defined hierarchy and your data structures relate to each other in an intuitive fashion. Of course, the real world of programming is never as clean as you’d like, but keep this principle in mind whenever you create a new object, add a new dependency, or modify relational structures.
- Does the object cleanly fit within the existing hierarchy? If not, do you need to change the new object, or re-align the hierarchy?
- How does this data structure relate to that other data structure? What will happen if the relations change? Will you need to re-align the relational structures?
Keeping your objects and data structures neatly aligned will result in easier to understand relations and hierarchies.
Proximity
The principle of proximity is that related items should be grouped together. Grouping things together is simple way to show relatedness. In software development, that generally means putting related functions into the same module, and related modules into the same package. Helper functions should be located near the functions that call them. Basically, group blocks of code in a logically consistent manner. And if possible, put documentation and tests close to the code too (python’s doctest module provides a great way to do that). One of the major benefits of following this principle is that it reduces the amount of time you’ll spend searching thru and understanding your own code. If all your code is organized in logical groups, and related functions are near each other in the same file, then it’s much easier to find a particular block of code.
Contrast
The principle of contrast is that if two things are not the same, then make them very different. The goal with contrast is to make different things distinctive from each other. Naming is great place to apply this principle. Names are all you have to distinguish between objects, functions, variables, and modules, so make sure that your names are distinctive and descriptive. Good names can tell you exactly what something is, and even imply its properties and behavior. Use different naming styles for different types of things. Private variables could be prefixed with an underscore, like _private, versus public variables like public, and CamelCase class names, as in MyClassName. Having a distinctive naming style lets you know at a glance whether something is a class, variable, or function, making your code much more readable. Whatever naming style you choose, use it consistently.
Consistency
The principle of consistency, or repetition, is that you repeat design elements. Repetition helps patterns become internalized and instantly recognizable. For programming, that means keeping a consistent code style, with consistent naming practices. Also, try to use well known standard conventions and protocols, shared libraries, and design patterns. Your code should make sense, or at least be readable, to those familiar with the language and domain. You’re not just writing code for yourself, you might be writing code for other programmers, maybe your manager, but most importantly, you’re writing code for your future self. It always sucks coming back to code you haven’t touched in months and not knowing what the hell is going on. Consistent style and software design can save you from that headache.
Programming as Design
If all this seems like obvious common sense to you, then great! But common sense isn’t always so common. The point of this article is make you aware that everyday software programming is filled with design choices. Naming a variable is a design choice. Creating a new module is a design choice. The layout of your working directory is a design choice. Be conscious of these choices and use the above principles and to inform your decisions. The choices you make communicate how the software works and how the code fits together. Make every choice deliberate and justifiable. Use refactoring to improve the design without affecting the functionality.
