I'm the one who wrote the post, and in retrospect I can see why people would be a bit confused at this example.

I started out wanting to explain my actual implementation of a 'yield' command. As I wrote the post, though, it grew overcomplicated and filled with explanations of Scheme's syntax macros, which was not at all my intention.

I guess in simplifying the implementation I also lost a bit of the idea behind it. You do need continuations to implement a general-case yield; if you just want generators for a list, you can use closers (and be more efficient, too).

Thanks to you (and to parent) for pointing that out; if you don't mind, I'll add mention of what you said to the blog post?