Change and decay in all around I see…

Henry Francis Lyte“Abide with Me”

Chapter 3Immutability

If you listen to functional-programming aficionados, you’ll hear people making a big deal about immutability—the fact that in a functional program, data cannot be altered once created.

And, indeed, Elixir enforces immutable data.

But why?

Get Programming Elixir ≥ 1.6 now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.