It would be extremely awkward, you'd need a big dispatch table handling the generator's result and send()ing restarts up to the generator, and of course you lose condition's ability to work through stacks of blissfully unaware code, and to have default behaviors (in Smalltalk, the default behavior — in an interactive image — is to pop up a dialog asking the user if he wants to unwind the stack [as in an exception], to open a debugger at condition point or to try resuming the condition [under the assumption that the user fixed some incorrect method, or checked his network access])

    ...
    except SomethingBad:
        yield None 
        restartRequest = yield None
        if restartRequest:
            do whatever is necessary to go on

although perhaps passing a 'handlers' object down, with which handler functions could be registered might be better?