In Node.js environments, the majority of side-effects come in the form of IO. This is what Node.js excels at—orchestrating huge volumes of IO operations. This is why it has a stream API that most IO components implement.

In this chapter, we'll look at Immutable.js collections from the perspective of Node.js IO. You'll learn how to do the following:

• Reading and parsing CSV data into Immutable.js collections
• Handling the parsing of lots of input data
• Iterating over collections to write data
• Writing collection values asynchronously to streams
• Chaining streams together and lazily processing Immutable.js sequences