Stationary drill

You can even build a computer within Minecraft but there's not a way to put a redstone circuit to break a block (unless it's gravel or sand). That's why I suggest the creation of a stationary drill, that when powered by redstone, would dig/mine the block in front of it, if the block can be mined with a iron pickaxe, or do nothing otherwise (like a blocked piston). This would allow to make a fully automatic stone brick manufacturing machine, using just buckets of water and lava. The drill stationary drill could still be used as mortal trap. It would be made out of a sticky piston and a stone cutter combined.