Connecting Functions – Pipelining, Composition, and More

In Chapter 7, Transforming Functions, we looked at ways to build new functions by applying higher-order functions. In this chapter, we will go to the core of FP and learn how to create sequences of function calls and how to combine them to produce a more complex result out of several simpler components. To do this, we will cover the following topics:

• Pipelining: A way to join functions, similar to Unix/Linux pipes
• Chaining: A variant of pipelining, but restricted to objects
• Composing: A classic operation with its origins in basic computer theory
• Transducing: An optimized way to compose map, filter, or reduce operations

Along the way, we will be touching on related concepts, such as the following:

• Pointfree style, which is often used with pipelining and composition
• Debugging of composed or piped functions, for which we’ll whip up some auxiliary tools
• Testing for these functions...