add fifo_queue.add_list() and use it to eliminate an inner loop

mesecons/fifo_queue.lua

@@ -20,6 +20,11 @@ function fifo_queue.add(self, v)
 	self.buf_in[n] = v
 end
 
+-- add several elements to the queue
+function fifo_queue.add_list(self, v)
+	table.move(v, 1, #v, self.n_in + 1, self.buf_in)
+	self.n_in = self.n_in + #v
+end
 -- removes and returns the next element, or nil of empty
 function fifo_queue.take(self)
 	local i_out = self.i_out

mesecons_mvps/init.lua

@@ -85,9 +85,10 @@ function mesecon.mvps_get_stack(pos, dir, maximum, all_pull_sticky)
 			if minetest.registered_nodes[nn.name]
 			and minetest.registered_nodes[nn.name].mvps_sticky then
 				local connected = minetest.registered_nodes[nn.name].mvps_sticky(np, nn)
-				for _, cp in ipairs(connected) do
+				frontiers:add_list(connected)
+				--[[for _, cp in ipairs(connected) do
 					frontiers:add(cp)
-				end
+				end]]
 			end
 
 			frontiers:add(vector.add(np, dir))