Summary

As we have seen in this first chapter, FP is not exactly the “new kid on the block.” It is a paradigm that stems from the work of Alonzo Church in the 1930s. It has seen continuous and steady investment since the 1950s with various languages pushing the paradigm further and further.

As we have also seen, FP and OOP are being combined more and more in modern languages, with Java and C# integrating ideas from the functional paradigm into their object-oriented paradigm. Go, the star of this book, takes this a step further and is a multi-paradigm language. Go gives us complete freedom to write code in whichever domain suits us best.

The core idea to remember from this chapter is that the FP paradigm will help us write code that is easier to test, read, and maintain. It reduces cognitive overhead by limiting side effects, not mutating the state of our system, and favoring small composable functions.

Finally, it is also important to remember that, although we advocate for the FP paradigm in this book, Go is multi-paradigm, and we have to choose the right paradigm for the problem we are solving.