human
Here's a good function header given the following:
I wrote the below code

    def do_one_brl(expr):
        yielded = False
        for brl in brules:
            for nexpr in brl(expr):
                yielded = True
                (yield nexpr)
            if yielded:
                return
    return do_one_brl

What's a good function header?
assistant
#Here's a good function header.

def do_one(*brules):