A modern programming language that makes developers happier.

kotlinlang

So am I right in thinking that sequences built via yielding are necessarily unbuffered, and that if I want some buffering I'll need to use channels?

What do you mean "buffered"? If just collect each N values to list it's possible using chunked operator
But you just should understand that sequences are sequential, they are not asyncronous, they block consumer, so `buffer` in this case doesn't make a lot of sense, producer and consumer block each other nothing to buffer in terms of asyncronous work