Correct (almost) all luacheck warnings

Also includes a few code opimizations:
- Combined mining drill functions
- Shorter alias registration (unused?)
- Add TODOs to address later

technic/machines/HV/forcefield.lua

@@ -112,10 +112,13 @@ local function set_forcefield_formspec(meta)
 	else
 		formspec = formspec.."button[0,1;5,1;mesecon_mode_0;"..S("Controlled by Mesecon Signal").."]"
 	end
+	-- TODO: String replacement with %s will stop working with client-side translations
 	if meta:get_int("enabled") == 0 then
-		formspec = formspec.."button[0,1.75;5,1;enable;"..S("%s Disabled"):format(S("%s Forcefield Emitter"):format("HV")).."]"
+		formspec = formspec.."button[0,1.75;5,1;enable;"..
+			S("%s Disabled"):format(S("%s Forcefield Emitter"):format("HV")).."]"
 	else
-		formspec = formspec.."button[0,1.75;5,1;disable;"..S("%s Enabled"):format(S("%s Forcefield Emitter"):format("HV")).."]"
+		formspec = formspec.."button[0,1.75;5,1;disable;"..
+			S("%s Enabled"):format(S("%s Forcefield Emitter"):format("HV")).."]"
 	end
 	meta:set_string("formspec", formspec)
 end

technic/machines/HV/quarry.lua

@@ -47,14 +47,19 @@ local function set_quarry_demand(meta)
 	local radius = meta:get_int("size")
 	local diameter = radius*2 + 1
 	local machine_name = S("%s Quarry"):format("HV")
-	if meta:get_int("enabled") == 0 or meta:get_int("purge_on") == 1 then
-		meta:set_string("infotext", S(meta:get_int("purge_on") == 1 and "%s purging cache" or "%s Disabled"):format(machine_name))
+	local do_purge = meta:get_int("purge_on") == 1
+	if meta:get_int("enabled") == 0 or do_purge then
+		local infotext = do_purge and
+			S("%s purging cache") or S("%s Disabled")
+		meta:set_string("infotext", infotext:format(machine_name))
 		meta:set_int("HV_EU_demand", 0)
 	elseif meta:get_int("dug") == diameter*diameter * (quarry_dig_above_nodes+1+quarry_max_depth) then
 		meta:set_string("infotext", S("%s Finished"):format(machine_name))
 		meta:set_int("HV_EU_demand", 0)
 	else
-		meta:set_string("infotext", S(meta:get_int("HV_EU_input") >= quarry_demand and "%s Active" or "%s Unpowered"):format(machine_name))
+		local infotext = meta:get_int("HV_EU_input") >= quarry_demand
+			and S("%s Active") or S("%s Unpowered")
+		meta:set_string("infotext", infotext:format(machine_name))
 		meta:set_int("HV_EU_demand", quarry_demand)
 	end
 end

technic/machines/MV/power_radiator.lua

@@ -36,7 +36,8 @@ technic.register_inductive_machine = function(name)
 end
 
 -- Appliances:
---  has_supply: pos of supply node if the appliance has a power radiator near with sufficient power for the demand else ""
+--  has_supply: pos of supply node if the appliance has a power radiator near
+--              with sufficient power for the demand else ""
 --  EU_demand: The power demand of the device.
 --  EU_charge: Actual use. set to EU_demand if active==1
 --  active: set to 1 if the device is on

technic/machines/other/anchor.lua

@@ -48,20 +48,23 @@ local function forceload_on(pos, meta)
 end
 
 local function set_display(pos, meta)
+	local ESC = minetest.formspec_escape
 	meta:set_string("infotext", S(meta:get_int("enabled") ~= 0 and "%s Enabled" or "%s Disabled"):format(desc))
 	meta:set_string("formspec",
 		"size[5,3.5]"..
 		"item_image[0,0;1,1;technic:admin_anchor]"..
-		"label[1,0;"..minetest.formspec_escape(desc).."]"..
-		"label[0,1;"..minetest.formspec_escape(S("Owner:").." "..meta:get_string("owner")).."]"..
+		"label[1,0;"..ESC(desc).."]"..
+		"label[0,1;"..ESC(S("Owner:").." "..meta:get_string("owner")).."]"..
 		(meta:get_int("locked") == 0 and
-			"button[3,1;2,1;lock;"..minetest.formspec_escape(S("Unlocked")).."]" or
-			"button[3,1;2,1;unlock;"..minetest.formspec_escape(S("Locked")).."]")..
-		"field[0.25,2.3;1,1;radius;"..minetest.formspec_escape(S("Radius:"))..";"..meta:get_int("radius").."]"..
+			"button[3,1;2,1;lock;"..ESC(S("Unlocked")).."]" or
+			"button[3,1;2,1;unlock;"..ESC(S("Locked")).."]")..
+		"field[0.25,2.3;1,1;radius;"..ESC(S("Radius:"))..";"..meta:get_int("radius").."]"..
 		(meta:get_int("enabled") == 0 and
-			"button[3,2;2,1;enable;"..minetest.formspec_escape(S("Disabled")).."]" or
-			"button[3,2;2,1;disable;"..minetest.formspec_escape(S("Enabled")).."]")..
-		"label[0,3;"..minetest.formspec_escape(S("Keeping %d/%d map blocks loaded"):format(#currently_forceloaded_positions(meta), #compute_forceload_positions(pos, meta))).."]")
+			"button[3,2;2,1;enable;"..ESC(S("Disabled")).."]" or
+			"button[3,2;2,1;disable;"..ESC(S("Enabled")).."]")..
+		"label[0,3;"..ESC(S("Keeping %d/%d map blocks loaded"):format(
+			#currently_forceloaded_positions(meta), #compute_forceload_positions(pos, meta)
+		)).."]")
 end
 
 minetest.register_node("technic:admin_anchor", {
@@ -80,7 +83,8 @@ minetest.register_node("technic:admin_anchor", {
 	end,
 	can_dig = function (pos, player)
 		local meta = minetest.get_meta(pos)
-		return meta:get_int("locked") == 0 or (player and player:is_player() and player:get_player_name() == meta:get_string("owner"))
+		return meta:get_int("locked") == 0 or
+			(player and player:is_player() and player:get_player_name() == meta:get_string("owner"))
 	end,
 	on_destruct = function (pos)
 		local meta = minetest.get_meta(pos)
@@ -99,7 +103,11 @@ minetest.register_node("technic:admin_anchor", {
 			forceload_off(meta)
 			if fields.disable then meta:set_int("enabled", 0) end
 			if fields.enable then meta:set_int("enabled", 1) end
-			if fields.radius and string.find(fields.radius, "^[0-9]+$") and tonumber(fields.radius) < 256 then meta:set_int("radius", fields.radius) end
+			if fields.radius
+					and string.find(fields.radius, "^[0-9]+$")
+					and tonumber(fields.radius) < 256 then
+				meta:set_int("radius", fields.radius)
+			end
 			if meta:get_int("enabled") ~= 0 then
 				forceload_on(pos, meta)
 			end

technic/machines/other/frames.lua

@@ -88,22 +88,22 @@ local function pos_in_list(l, pos)
 	return false
 end
 
-local function table_empty(table)
-	for _, __ in pairs(table) do
+local function table_empty(what)
+	for _ in pairs(what) do
 		return false
 	end
 	return true
 end
 
-local function add_table(table, toadd)
+local function add_table(what, toadd)
 	local i = 1
 	while true do
-		local o = table[i]
+		local o = what[i]
 		if o == toadd then return end
 		if o == nil then break end
 		i = i + 1
 	end
-	table[i] = toadd
+	what[i] = toadd
 end
 
 local function move_nodes_vect(poslist, vect, must_not_move, owner)
@@ -398,20 +398,6 @@ minetest.register_entity("technic:frame_entity", {
 		local pos = vector.round(self.object:getpos())
 		frames_pos[pos_to_string(pos)] = node.name
 
-		local stack = ItemStack(node.name)
-		local itemtable = stack:to_table()
-		local itemname = nil
-
-		if itemtable then
-			itemname = stack:to_table().name
-		end
-
-		local item_texture = nil
-		local item_type = ""
-		if minetest.registered_items[itemname] then
-			item_texture = minetest.registered_items[itemname].inventory_image
-			item_type = minetest.registered_items[itemname].type
-		end
 		local prop = {
 			is_visible = true,
 			textures = { node.name },

technic/machines/register/battery_box.lua

@@ -304,9 +304,9 @@ function technic.register_battery_box(data)
 			drop = "technic:"..ltier.."_battery_box0",
 			on_construct = function(pos)
 				local meta = minetest.get_meta(pos)
-				local EU_upgrade, tube_upgrade = 0, 0
+				local EU_upgrade, _ = 0
 				if data.upgrade then
-					EU_upgrade, tube_upgrade = technic.handle_machine_upgrades(meta)
+					EU_upgrade, _ = technic.handle_machine_upgrades(meta)
 				end
 				local max_charge = data.max_charge * (1 + EU_upgrade / 10)
 				local charge = meta:get_int("internal_EU_charge")
@@ -345,9 +345,9 @@ function technic.register_battery_box(data)
 					meta = minetest.get_meta(pos)
 					if not pipeworks.may_configure(pos, sender) then return end
 					fs_helpers.on_receive_fields(pos, fields)
-					local EU_upgrade, tube_upgrade = 0, 0
+					local EU_upgrade, _ = 0
 					if data.upgrade then
-						EU_upgrade, tube_upgrade = technic.handle_machine_upgrades(meta)
+						EU_upgrade, _ = technic.handle_machine_upgrades(meta)
 					end
 					local max_charge = data.max_charge * (1 + EU_upgrade / 10)
 					local charge = meta:get_int("internal_EU_charge")

technic/machines/register/cables.lua

@@ -63,22 +63,27 @@ local function clear_networks(pos)
 				-- This is similar to check_node_subp
 				technic.cables[minetest.hash_node_position(pos)] = network_id
 				pos.visited = 1
-				if technic.is_tier_cable(name, tier) then
+				if technic.is_tier_cable(node.name, tier) then
+					-- Found a cable
 					table.insert(network.all_nodes,pos)
 				elseif technic.machines[tier][node.name] then
-					meta:set_string(tier.."_network",minetest.pos_to_string(sw_pos))
-					if     technic.machines[tier][node.name] == technic.producer then
+					-- Found a machine
+					local eu_type = technic.machines[tier][node.name]
+					meta:set_string(tier.."_network", minetest.pos_to_string(sw_pos))
+					if     eu_type == technic.producer then
 						table.insert(network.PR_nodes,pos)
-					elseif technic.machines[tier][node.name] == technic.receiver then
+					elseif eu_type == technic.receiver then
 						table.insert(network.RE_nodes,pos)
-					elseif technic.machines[tier][node.name] == technic.producer_receiver then
+					elseif eu_type == technic.producer_receiver then
 						table.insert(network.PR_nodes,pos)
 						table.insert(network.RE_nodes,pos)
-					elseif technic.machines[tier][node.name] == "SPECIAL" and
+					elseif eu_type == "SPECIAL" and
 							(pos.x ~= sw_pos.x or pos.y ~= sw_pos.y or pos.z ~= sw_pos.z) and
-							from_below then
+							nil then
+						-- TODO: This case was never executed. Needs testing!
+						-- Supply converter.
 						table.insert(network.SP_nodes,pos)
-					elseif technic.machines[tier][node.name] == technic.battery then
+					elseif eu_type == technic.battery then
 						table.insert(network.BA_nodes,pos)
 					end
 				end

technic/machines/switching_station.lua

@@ -45,14 +45,12 @@ minetest.register_node("technic:switching_station",{
 		meta:set_string("active", 1)
 		meta:set_string("channel", "switching_station"..minetest.pos_to_string(pos))
 		meta:set_string("formspec", "field[channel;Channel;${channel}]")
-		local poshash = minetest.hash_node_position(pos)
 		technic.redundant_warn.poshash = nil
 	end,
 	after_dig_node = function(pos)
 		minetest.forceload_free_block(pos)
 		pos.y = pos.y - 1
 		minetest.forceload_free_block(pos)
-		local poshash = minetest.hash_node_position(pos)
 		technic.redundant_warn.poshash = nil
 	end,
 	on_receive_fields = function(pos, formname, fields, sender)
@@ -248,18 +246,15 @@ minetest.register_abm({
 	chance     = 1,
 	action = function(pos, node, active_object_count, active_object_count_wider)
 		if not technic.powerctrl_state then return end
-		local meta             = minetest.get_meta(pos)
+		local meta = minetest.get_meta(pos)
 		local meta1
-		local pos1             = {}
-
-		local tier      = ""
 		local PR_nodes
 		local BA_nodes
 		local RE_nodes
 		local machine_name = S("Switching Station")
 
 		-- Which kind of network are we on:
-		pos1 = {x=pos.x, y=pos.y-1, z=pos.z}
+		local pos1 = {x=pos.x, y=pos.y-1, z=pos.z}
 
 		--Disable if necessary
 		if meta:get_int("active") ~= 1 then