That’s about to change. Not only are languages like Java or Python adopting more and more concepts from functional programming. Newer languages like Haskell are going completely functional.

The preceding examples offer a hands-on understanding of functional programming in a focused context, but functional programming is intended to drive greater benefits to programming in the large.

Before Haskell, academic researchers had implemented certain functional concepts in the languages they worked with. But in the late 1980s, a group of computer scientists came together to smelt ...