for(var/bad_code in world)

Removes a very large amount of world loops.
Adds a macro to painlessly generate a global list, and the needed code to modify the list when an object is made or deleted automatically.
Cleans up some commented out code.

code/modules/events/escaped_slimes.dm

@@ -32,7 +32,7 @@
 
 /datum/event/escaped_slimes/start()
 	var/list/vents = list()
-	for(var/obj/machinery/atmospherics/unary/vent_pump/temp_vent in world)
+	for(var/obj/machinery/atmospherics/unary/vent_pump/temp_vent in machines)
 		if(temp_vent.network && temp_vent.loc.z in using_map.station_levels) //borrowed from spiders event, but it works. Distribute the slimes only in rooms with vents
 			vents += temp_vent
 

code/modules/events/gravity.dm

@@ -16,7 +16,7 @@
 
 /datum/event/gravity/start()
 	gravity_is_on = 0
-	for(var/area/A in world)
+	for(var/area/A in all_areas)
 		if(A.z in zLevels)
 			A.gravitychange(gravity_is_on, A)
 
@@ -24,7 +24,7 @@
 	if(!gravity_is_on)
 		gravity_is_on = 1
 
-		for(var/area/A in world)
+		for(var/area/A in all_areas)
 			if(A.z in zLevels)
 				A.gravitychange(gravity_is_on, A)
 

code/modules/events/ion_storm.dm

@@ -12,7 +12,7 @@
 			continue
 		players += player.real_name
 
-	for (var/mob/living/silicon/ai/target in world)
+	for (var/mob/living/silicon/ai/target in silicon_mob_list)
 		var/law = target.generate_ion_law()
 		target << "<font color='red'><b>You have detected a change in your laws information:</b></font>"
 		target << law
@@ -30,7 +30,7 @@
 
 /datum/event/ionstorm/tick()
 	if(botEmagChance)
-		for(var/mob/living/bot/bot in world)
+		for(var/mob/living/bot/bot in mob_list)
 			if(prob(botEmagChance))
 				bot.emag_act(1)
 
@@ -146,7 +146,7 @@ Would like to add a law like "Law x is _______" where x = a number, and _____ is
 					M.add_ion_law("THE STATION IS [who2pref] [who2]")
 
 	if(botEmagChance)
-		for(var/obj/machinery/bot/bot in world)
+		for(var/obj/machinery/bot/bot in mob_list)
 			if(prob(botEmagChance))
 				bot.Emag()
 */
@@ -162,21 +162,21 @@ Would like to add a law like "Law x is _______" where x = a number, and _____ is
 
 	spawn(0)
 		world << "Started processing APCs"
-		for (var/obj/machinery/power/apc/APC in world)
+		for (var/obj/machinery/power/apc/APC in machines)
 			if(APC.z in station_levels)
 				APC.ion_act()
 				apcnum++
 		world << "Finished processing APCs. Processed: [apcnum]"
 	spawn(0)
 		world << "Started processing SMES"
-		for (var/obj/machinery/power/smes/SMES in world)
+		for (var/obj/machinery/power/smes/SMES in machines)
 			if(SMES.z in station_levels)
 				SMES.ion_act()
 				smesnum++
 		world << "Finished processing SMES. Processed: [smesnum]"
 	spawn(0)
 		world << "Started processing AIRLOCKS"
-		for (var/obj/machinery/door/airlock/D in world)
+		for (var/obj/machinery/door/airlock/D in machines)
 			if(D.z in station_levels)
 				//if(length(D.req_access) > 0 && !(12 in D.req_access)) //not counting general access and maintenance airlocks
 				airlocknum++
@@ -185,7 +185,7 @@ Would like to add a law like "Law x is _______" where x = a number, and _____ is
 		world << "Finished processing AIRLOCKS. Processed: [airlocknum]"
 	spawn(0)
 		world << "Started processing FIREDOORS"
-		for (var/obj/machinery/door/firedoor/D in world)
+		for (var/obj/machinery/door/firedoor/D in machines)
 			if(D.z in station_levels)
 				firedoornum++;
 				spawn(0)

code/modules/events/money_hacker.dm

@@ -20,7 +20,7 @@
 	Notifications will be sent as updates occur.<br>"
 	var/my_department = "[station_name()] firewall subroutines"
 
-	for(var/obj/machinery/message_server/MS in world)
+	for(var/obj/machinery/message_server/MS in machines)
 		if(!MS.active) continue
 		MS.send_rc_message("Head of Personnel's Desk", my_department, message, "", "", 2)
 
@@ -62,6 +62,6 @@
 
 	var/my_department = "[station_name()] firewall subroutines"
 
-	for(var/obj/machinery/message_server/MS in world)
+	for(var/obj/machinery/message_server/MS in machines)
 		if(!MS.active) continue
 		MS.send_rc_message("Head of Personnel's Desk", my_department, message, "", "", 2)

code/modules/events/prison_break.dm

@@ -41,14 +41,14 @@
 
 
 /datum/event/prison_break/start()
-	for(var/area/A in world)
+	for(var/area/A in all_areas)
 		if(is_type_in_list(A,areaType) && !is_type_in_list(A,areaNotType))
 			areas += A
 
 	if(areas && areas.len > 0)
 		var/my_department = "[station_name()] firewall subroutines"
 		var/rc_message = "An unknown malicious program has been detected in the [english_list(areaName)] lighting and airlock control systems at [stationtime2text()]. Systems will be fully compromised within approximately three minutes. Direct intervention is required immediately.<br>"
-		for(var/obj/machinery/message_server/MS in world)
+		for(var/obj/machinery/message_server/MS in machines)
 			MS.send_rc_message("Engineering", my_department, rc_message, "", "", 2)
 		for(var/mob/living/silicon/ai/A in player_list)
 			A << "<span class='danger'>Malicious program detected in the [english_list(areaName)] lighting and airlock control systems by [my_department].</span>"

code/modules/events/spider_infestation.dm

@@ -16,7 +16,7 @@
 
 /datum/event/spider_infestation/start()
 	var/list/vents = list()
-	for(var/obj/machinery/atmospherics/unary/vent_pump/temp_vent in world)
+	for(var/obj/machinery/atmospherics/unary/vent_pump/temp_vent in machines)
 		if(!temp_vent.welded && temp_vent.network && temp_vent.loc.z in using_map.station_levels)
 			if(temp_vent.network.normal_members.len > 50)
 				vents += temp_vent