> This is not a dig at anyone's project or language, but "read the source code" comments always strike me as unhelpful.

I agree, reading the source is a good way to learn more once a person already know the language.

It can be great to help track down a bug, or learn about an obscure corner case in a function, or see more advanced idioms in use, but it's a pretty terrible and unfriendly way to learn a language in the first place.