Dan Brian writes: > Having push and pull operate on opposite ends of an array strikes me > as more confusing than even shift.
It makes good sense to me -- if we're trying to move a piano from you to me then either you can push or your end or I can pull on my end: we're operating on different ends of it, but the effect in both cases is moving in one direction. Now instead of a piano imagine one of those conveyor belts that you get at supermarket checkouts: you push your goods on one-end, and the cashier pulls them off the other. When the cashier pulls one item off that unbreaks the light beam to the sensor, which triggers the motor, and all the other items get pulled along too, moving one place along. Smylers
