Somewhat unrelated to the article, but I always find the foo/bar style of code examples difficult to read. It's especially egregious here ; one of the points of

Somewhat unrelated to the article, but I always find the foo/bar style of code examples difficult to read. It's especially egregious here ; one of the points of the article is that types are often easy to guess from variable names, but it's very much not the case when the code is doSomethingWithFoo(foo) I feel like simple but more realistic snippets are much better teaching tools.