Functional Programming Patterns in Scala and Clojure

Pattern 15

Chain of Operations

Intent

To chain a sequence of computations together—this allows us to work cleanly with immutable data without storing lots of temporary results.

Overview

Sending some bit of data through a set of operations is a useful technique. This is especially true when working with immutable data. Since we can’t mutate a data structure, we need to send an immutable one through a series of transformations if we want to make more than a single change.

Another reason we chain operations is because it leads to succinct code. For instance, the builder we saw in Pattern 4, ​Replacing Builder for Immutable Object​, chains setting operations to keep our code lean, as the following snippet shows:

JavaExamples/src/main/java/com/mblinn/oo/javabean/PersonHarness.java ...