[bogaczio]

I think the performance issue is addressed, in the second paragraph, because you're quite right that it would create a slowdown. This library is quite simple, and it's mostly an exploration of a potential design pattern, not intended, nor recommended, as a generic solution.

The channel ownership isn't so much of an issue, at least the way I understand the question, since currently each Operator creates its own "output" channel, and is effectively the producer for that channel. The way this works in practice is that you instantiate an input channel, combine multiple operators together, and when your input is done, you close that input channel, which closes all of the subsequent channels in turn (because of the for ... range ch being used). That said, in practice I have used a separate channel for error reporting, which is lightly addressed near the end of the article.

The point about annotating channels is very good, I'll probably be making a change to incorporate that here soon.

Thanks for reading, and I appreciate the good feedback!