Guido van Rossum:
One [of many separate ideas in PEP 340] is turning generators into more general coroutines: continue EXPR passes the expression to the iterator's next() method ...
I would have been very happy with that a week ago. Seeing the specific implementation changed my mind. The caller shouldn't know what state the generator is in, so the passed-in-message will be the same regardless of which yield accepts it. Unless I have a single-yield generator, this means I end up writing boilerplate code to accept and process the arg at each yield. I don't want more boilerplate.
Even without a block-statement, these two changes make yield look a lot like invoking a thunk
Though it feels backwards to me; yield is returning control to something that already had to coordinate the thunks itself. -jJ