reverse generator

[ichabod801]

what i need is the ability to run, keeping it's state, and, instead of (or maybe in addition to) the ability to yield data, the ability to send data in the other direction (to the reverse generator). a simple example would be a thing that accepts multiple data items one at a time and builds a list of them all, returning that list when done.

How is what you're asking for different from a list? A list can do all of that. Use pop to yield data, append to send data (multiple items one at a time), it builds a list, and is a list whenever you're done.