class SyntaxTree::ARef

ARef represents when you’re pulling a value out of a collection at a specific index. Put another way, it’s any time you’re calling the method [].

collection[index]

The nodes usually contains two children, the collection and the index. In some cases, you don’t necessarily have the second child node, because you can call procs with a pretty esoteric syntax. In the following example, you wouldn’t have a second child node:

collection[]