Introduce utility function for deriving table fields

machines/transformer.lua

@@ -15,8 +15,7 @@
 -- along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 local S=minetest.get_translator("industrialtest")
-industrialtest.Transformer=table.copy(industrialtest.ElectricMachine)
-industrialtest.internal.unpackTableInto(industrialtest.Transformer,{
+industrialtest.Transformer=industrialtest.internal.derive(industrialtest.ElectricMachine,{
 	withoutFormspec=true,
 	facedir=true,
 	storageLists={},
@@ -59,8 +58,7 @@ function industrialtest.Transformer.onPowerFlow(self,pos)
 	self:trigger(pos)
 end
 
-industrialtest.LVTransformer=table.copy(industrialtest.Transformer)
-industrialtest.internal.unpackTableInto(industrialtest.LVTransformer,{
+industrialtest.LVTransformer=industrialtest.internal.derive(industrialtest.Transformer,{
 	name="industrialtest:lv_transformer",
 	description=S("LV Transformer"),
 	sounds="wood",
@@ -89,8 +87,7 @@ minetest.register_craft({
 	}
 })
 
-industrialtest.MVTransformer=table.copy(industrialtest.Transformer)
-industrialtest.internal.unpackTableInto(industrialtest.MVTransformer,{
+industrialtest.MVTransformer=industrialtest.internal.derive(industrialtest.Transformer,{
 	name="industrialtest:mv_transformer",
 	description=S("MV Transformer"),
 	sounds="metal",
@@ -120,8 +117,7 @@ minetest.register_craft({
 	}
 })
 
-industrialtest.HVTransformer=table.copy(industrialtest.Transformer)
-industrialtest.internal.unpackTableInto(industrialtest.HVTransformer,{
+industrialtest.HVTransformer=industrialtest.internal.derive(industrialtest.Transformer,{
 	name="industrialtest:hv_transformer",
 	description=S("HV Transformer"),
 	sounds="metal",
@@ -151,8 +147,7 @@ minetest.register_craft({
 	}
 })
 
-industrialtest.EVTransformer=table.copy(industrialtest.Transformer)
-industrialtest.internal.unpackTableInto(industrialtest.EVTransformer,{
+industrialtest.EVTransformer=industrialtest.internal.derive(industrialtest.Transformer,{
 	name="industrialtest:ev_transformer",
 	description=S("EV Transformer"),
 	sounds="metal",