Functional Thinking

Chapter 3. Cede

Confession: I never want to work in a non-garbage-collected language again. I paid my dues in languages like C++ for too many years, and I don’t want to surrender the conveniences of modern languages. That’s the story of how software development progresses. We build layers of abstraction to handle (and hide) mundane details. As the capabilities of computers have grown, we’ve offloaded more tasks to languages and runtimes. Developers used to shun interpreted languages as too slow, but they are now commonplace. Many of the features of functional languages were prohibitively slow a decade ago but make perfect sense now because they optimize developer time and effort.

One of the values of functional thinking is the ability to cede control of low-level details (such as garbage collection) to the runtime, eliminating a swath of bugs you must chase. While many developers are accustomed to blissful ignorance for bedrock abstractions such as memory, they are less accustomed to similar abstractions appearing at a higher level. Yet these higher-level abstractions serve the same purpose: handling the mundane details of machinery while freeing developers to work on unique aspects of their problems.

In this chapter, I show five ways developers in functional languages can cede control to the language or runtime, freeing themselves to work on more relevant problems.

Iteration to Higher-Order Functions

I already illustrated the first example of surrendering control in Example 2-3, replacing ...