The author seems confused, as the code here doesn't actually involve recursion. I wouldn't normally nitpick too hard, here, but he spends a lot of time talking about how Elixer made it possible for him to understand and use recursion... The trouble is neither of these things seemed to have happened...
I hate to be one of those that complain about the website itself and not the content but this one annoyed me greatly.<p>This site is another one that requires javascript to see any content for no apparent reason. Worse when scrolling on a narrow window (so that search is not on the right) like on a tablet, when you scroll up it jumps to the top rather than scrolling up so you lose where you are. When you scroll back down it jumps back to where it was so its hard to scroll up reliably.<p>Also regarding the content, I actually prefer the original code for some reason over the multitude of helper functions. But I guess that is a matter of style.
I'm sorry but that article is terrible. I don't even program in elixir, but if you are trying to don't even use this. There is no recursion, just pattern matching.