Rediscovery: OO and FP

I’ve noticed some of the sharpest developers I know are doing one or both of these things:

  • Rediscovering object oriented design. Practicing evolving a design, often driven by the pain points illuminated by automated tests. Thinking about coupling and cohesion. Trying to encapsulate the right behaviors and find decide which principles are the most appropriate to the languages and systems they’re using.

  • Rediscovering functions. Applying functional programming to everyday programming problems. Using the features of functional languages as an advantage to build concurrent and distributed systems. Finding the differences in functional design and writing more idiomatic code.

The first is a cyclical thing. It happened in Java, it happened in .NET, it’s happening in Ruby now. People come to a language for what makes it different, write a lot of stuff, and keep bumping into the same problems. They (re-)discover OO, start refactoring things and shaping their systems differently. Some people dig it, others dismiss it as too much effort or ceremony. A new thing comes along, and it all happens again.

The second is harder for me to read. I’ve spent a fair amount of time studying FP, though I have yet to apply it to production software. Despite that, I have come across a lot of good ideas that are already part of the code I work with daily, or that I wish was part of the code I work with. FP has good answers to composing systems, reasoning about state, and handling concurrency. It has often suffered from a lack of pragmatism, overly dense literature, and rough tooling. The ideas are worth stealing, even if they haven’t broadly succeeded.

Both of these trends are crucial to moving the practice of software development forward. We need to keep rediscovering and sharpening old ideas whilst experimenting with new ideas to find out which ones are good and which ones less so.