Merge pull request #170 from grilledham/safe_events

events rewrite

autodeconstruct.lua

@@ -1,4 +1,7 @@
 --Author: Valansch
+
+local Event = require "utils.event"
+
 local function is_depleted(drill)
   local position = drill.position
   local area = {}
@@ -33,4 +36,4 @@ local function on_resource_depleted(event)
   end
 end
 
-Event.register(defines.events.on_resource_depleted, on_resource_depleted)
+Event.add(defines.events.on_resource_depleted, on_resource_depleted)

band.lua

@@ -2,7 +2,7 @@
 -- Version 0.1.6
 -- https://github.com/Befzz/factorio_random/tree/master/scenarios/befzz_test
 
--- Requires event.lua to work ( https://github.com/3RaGaming/utils )
+local Event = require "utils.event"
 
 -- SETTINGS
 local option_band_change_interval = 60 * 3 -- in ticks
@@ -411,6 +411,6 @@ local function on_gui_elem_changed(event)
 
 end
 
-Event.register(defines.events.on_gui_elem_changed, on_gui_elem_changed)
+Event.add(defines.events.on_gui_elem_changed, on_gui_elem_changed)
-Event.register(defines.events.on_gui_click, on_gui_click)
+Event.add(defines.events.on_gui_click, on_gui_click)
-Event.register(defines.events.on_player_joined_game, create_band_gui)
+Event.add(defines.events.on_player_joined_game, create_band_gui)

base_data.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 if not global.score_biter_total_kills then global.score_biter_total_kills = 0 end
 
 local function biter_kill_counter(event)	
@@ -6,4 +8,4 @@ local function biter_kill_counter(event)
 	end		
 end
 
-Event.register(defines.events.on_entity_died, biter_kill_counter)
+Event.add(defines.events.on_entity_died, biter_kill_counter)

control.lua

@@ -1,5 +1,4 @@
 require "util"
-require "utils.event"
 require "config"
 require "utils.utils"
 require "utils.list_utils"
@@ -23,6 +22,7 @@ require "tasklist"
 require "autodeconstruct"
 require "corpse_util"
 require "reactor_meltdown"
+local Event = require "utils.event"
 
 local function player_joined(event)
 	local player = game.players[event.player_index]
@@ -64,5 +64,5 @@ function hodor(event)
 	end
 end
 
-Event.register(defines.events.on_player_created, player_joined)
+Event.add(defines.events.on_player_created, player_joined)
-Event.register(defines.events.on_console_chat, hodor)
+Event.add(defines.events.on_console_chat, hodor)

corpse_util.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 local ttl = 15*60*60
 local function on_init()
 	global.corpse_util = {}
@@ -28,6 +30,6 @@ local function remove_corpse_marks()
 	end
 end
 
-Event.register(-1, on_init)
+Event.on_init(on_init)
-Event.register(defines.events.on_player_died, mark_corpse)
+Event.add(defines.events.on_player_died, mark_corpse)
-Event.register(defines.events.on_tick, remove_corpse_marks)
+Event.add(defines.events.on_tick, remove_corpse_marks)

custom_commands.lua

@@ -1,5 +1,5 @@
 local Task = require "utils.Task"
-require "utils.event"
+local Event = require "utils.event"
 
 function player_print(str)
   if game.player then
@@ -256,7 +256,7 @@ local function built_entity(event)
   end
 end
 
-Event.register(defines.events.on_built_entity, built_entity)
+Event.add(defines.events.on_built_entity, built_entity)
 
 local function toggle_tp_mode(cmd)
   if not game.player or not (game.player.admin or is_mod(game.player.name)) then

fish_market.lua

@@ -17,6 +17,8 @@ make pet faster
 make pet follow you moar
 --]]
 
+local Event = require "utils.event"
+
 function spawn_market(cmd)
   if not game.player or not game.player.admin then
     cant_run(cmd.name)
@@ -402,7 +404,7 @@ function fish_player_crafted_item(event)
    end
 end
 
-Event.register(defines.events.on_pre_player_mined_item, pre_player_mined_item)
+Event.add(defines.events.on_pre_player_mined_item, pre_player_mined_item)
-Event.register(defines.events.on_entity_died, fish_drop_entity_died)
+Event.add(defines.events.on_entity_died, fish_drop_entity_died)
-Event.register(defines.events.on_market_item_purchased, market_item_purchased)
+Event.add(defines.events.on_market_item_purchased, market_item_purchased)
-Event.register(defines.events.on_player_crafted_item, fish_player_crafted_item)
+Event.add(defines.events.on_player_crafted_item, fish_player_crafted_item)

info.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 local function create_info_button(event)
 	local player = game.players[event.player_index]
 
@@ -78,5 +80,5 @@ local function on_gui_click(event)
 end
 
 
-Event.register(defines.events.on_gui_click, on_gui_click)
+Event.add(defines.events.on_gui_click, on_gui_click)
-Event.register(defines.events.on_player_joined_game, create_info_button)
+Event.add(defines.events.on_player_joined_game, create_info_button)

map_gen/combined/borg_planet.lua

@@ -1,6 +1,7 @@
 --Author: MewMew
 -- !! ATTENTION !! 
 -- Use water only in starting area as map setting!!!
+local Event = require "utils.event"
 require "map_gen.shared.perlin_noise"
 
 wreck_item_pool = {}
@@ -485,4 +486,4 @@ local function on_tick()
 end
 
 
-Event.register(defines.events.on_tick, on_tick)  --]]
+Event.add(defines.events.on_tick, on_tick)  --]]

map_gen/combined/dimensions.lua

@@ -1,5 +1,7 @@
 --Author: Valansch
 
+local Event = require "utils.event"
+
 local wrech_items_module = require "map_gen.misc.wreck_items"
 
 local resource_types = {"copper-ore", "iron-ore", "coal", "stone", "uranium-ore", "crude-oil"}
@@ -158,4 +160,4 @@ end
 
 commands.add_command("linkchests", "Select a chest to link to another. Run this command again to select the other one.", linkchests)
 commands.add_command("linkportals", "Select a portal to link to another. Run this command again to select the other one.", linkportals)
-Event.register(defines.events.on_tick, dim_on_tick)
+Event.add(defines.events.on_tick, dim_on_tick)

map_gen/combined/meteor_strike.lua

@@ -1,5 +1,6 @@
 require "map_gen.shared.perlin_noise"
 local Task = require "utils.Task"
+local Event = require "utils.event"
 
 local block_size = 1 -- in tiles
 local start_size = 64 -- in blocks
@@ -171,4 +172,4 @@ local function on_tick()
     end
 end
 
-Event.register(defines.events.on_tick, on_tick)
+Event.add(defines.events.on_tick, on_tick)

map_gen/misc/rail_grid.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 mymodule = {}
 
 local function rot_pos(pos, rot)
@@ -68,7 +70,7 @@ local function on_init()
 	connect_line({  4,  21}, { 15,  21})
 end
 
-Event.register(-1, on_init)
+Event.on_init(on_init)
 
 local function build_intersection(type, origin, rot)
   local surface = game.surfaces[1]

map_gen/misc/rusky_pvp.lua

@@ -1,4 +1,6 @@
-Event.register(-1,function()
+local Event = require "utils.event"
+
+Event.on_init(function()
   
   global.players = {}
   
@@ -9,7 +11,7 @@ Event.register(-1,function()
 
 end)
 
-Event.register(defines.events.on_player_created, function(event)
+Event.add(defines.events.on_player_created, function(event)
   local player = game.players[event.player_index]
   --player.print("Info: PVP server mod 'Bearded Snails' (c) byte");
   guiNewPlayer(player.gui.left);
@@ -27,7 +29,7 @@ Event.register(defines.events.on_player_created, function(event)
   player.force.chart(player.surface, {{player.position.x - 200, player.position.y - 200}, {player.position.x + 200, player.position.y + 200}})
 end)
 
-Event.register(defines.events.on_player_respawned, function(event)
+Event.add(defines.events.on_player_respawned, function(event)
   local player = game.players[event.player_index]
   
   player.insert{name="heavy-armor", count=1}
@@ -38,7 +40,7 @@ Event.register(defines.events.on_player_respawned, function(event)
   player.character.character_running_speed_modifier = 0.5
 end)
 
-Event.register(defines.events.on_rocket_launched, function(event)
+Event.add(defines.events.on_rocket_launched, function(event)
   local force = event.rocket.force
   if event.rocket.get_item_count("satellite") > 0 then
     if global.satellite_sent == nil then
@@ -66,7 +68,7 @@ Event.register(defines.events.on_rocket_launched, function(event)
   end
 end)
 
-Event.register(defines.events.on_gui_click, function(event)
+Event.add(defines.events.on_gui_click, function(event)
   local player = game.players[event.player_index]
   local gui = player.gui.left;
 

map_gen/presets/mobius_strip.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 map_gen_decoratives = false -- Generate our own decoratives
 map_gen_rows_per_tick = 8 -- Inclusive integer between 1 and 32. Used for map_gen_threaded, higher numbers will generate map quicker but cause more lag.
 
@@ -37,7 +39,7 @@ local function research_finished(event)
     end
 end
 
-Event.register(defines.events.on_research_finished, research_finished)
+Event.add(defines.events.on_research_finished, research_finished)
 
 local function max_axis_distance(world_x, world_y, target_x, target_y)
     local x = math.abs(world_x - target_x)

map_gen/terrain/mines.lua

@@ -1,4 +1,5 @@
 local Task = require "utils.Task"
+local Event = require "utils.event"
 
 local mines_factor = 4
 
@@ -30,4 +31,4 @@ local death_messages = {"Went exploring, and didn't bring a minesweeping kit.","
 local function player_died()
   game.print(death_messages[math.random(1, #death_messages)])
 end
-Event.register(defines.events.on_player_died, player_died)
+Event.add(defines.events.on_player_died, player_died)

map_layout.lua

@@ -5,6 +5,8 @@ If you want to add your own module, just add it to the others
 in this file and your run_*type*_module(event) function will be called.
 --]]
 
+local Event = require "utils.event"
+
 --combined--
 --require "map_gen.combined.island_resort"
 --require "map_gen.combined.red_planet_v2"
@@ -107,4 +109,4 @@ local on_chunk_generated = function(event)
 	end
 end
 
-Event.register(defines.events.on_chunk_generated, on_chunk_generated)
+Event.add(defines.events.on_chunk_generated, on_chunk_generated)

nuke_control.lua

@@ -1,4 +1,4 @@
-
+local Event = require "utils.event"
 
 function allowed_to_nuke(player)
   if type(player) == "table" then
@@ -117,8 +117,8 @@ local function on_capsule_used(event)
   end
 end
 
-Event.register(defines.events.on_player_ammo_inventory_changed, ammo_changed)
+Event.add(defines.events.on_player_ammo_inventory_changed, ammo_changed)
-Event.register(defines.events.on_player_deconstructed_area, on_player_deconstructed_area)
+Event.add(defines.events.on_player_deconstructed_area, on_player_deconstructed_area)
---Event.register(defines.events.on_player_mined_entity, on_player_mined_item)
+--Event.add(defines.events.on_player_mined_entity, on_player_mined_item)
-Event.register(defines.events.on_player_used_capsule, on_capsule_used)
+Event.add(defines.events.on_player_used_capsule, on_capsule_used)
 

on_tick.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 local function on_tick()
   walk_on_tick()
   if game.tick % 60 == 0 then
@@ -15,4 +17,4 @@ local function on_tick()
   end
 end
 
-Event.register(defines.events.on_tick, on_tick)
+Event.add(defines.events.on_tick, on_tick)

player_list.lua

@@ -16,6 +16,8 @@ things to do (maybe)
 make it sorted by time played
 --]]
 
+local Event = require "utils.event"
+
 local symbol_asc = "▲"
 local symbol_desc = "▼"
 
@@ -412,6 +414,6 @@ local function player_list_on_player_died(event)
 end
 
 
-Event.register(defines.events.on_player_joined_game, on_player_joined_game)
+Event.add(defines.events.on_player_joined_game, on_player_joined_game)
-Event.register(defines.events.on_gui_click, on_gui_click)
+Event.add(defines.events.on_gui_click, on_gui_click)
-Event.register(defines.events.on_player_died, player_list_on_player_died)
+Event.add(defines.events.on_player_died, player_list_on_player_died)

poll.lua

@@ -3,6 +3,8 @@
 -- by MewMew -- with some help from RedLabel, Klonan, Morcup, BrainClot
 ----------------------------------------------------------------------------------------------------------------------------------------
 
+local Event = require "utils.event"
+
 local function create_poll_gui(event)
 	local player = game.players[event.player_index]
 
@@ -317,6 +319,6 @@ function poll_on_second()
 	end
 end
 
-Event.register(defines.events.on_gui_click, on_gui_click)
+Event.add(defines.events.on_gui_click, on_gui_click)
-Event.register(defines.events.on_player_joined_game, create_poll_gui)
+Event.add(defines.events.on_player_joined_game, create_poll_gui)
-Event.register(defines.events.on_player_joined_game, poll_sync_for_new_joining_player)
+Event.add(defines.events.on_player_joined_game, poll_sync_for_new_joining_player)

reactor_meltdown.lua

@@ -3,6 +3,8 @@
 --
 --a reactors loses 2 damage per second at 1000°C
 
+local Event = require "utils.event"
+
 global.wastelands = {}
 global.reactors = {}
 local wasteland_duration_seconds = 300
@@ -114,9 +116,9 @@ local function entity_build(event)
   end
 end
 
-script.on_nth_tick(67, on_tick)
+Event.on_nth_tick(60, on_tick)
-Event.register(defines.events.on_player_mined_entity, entity_destroyed)
+Event.add(defines.events.on_player_mined_entity, entity_destroyed)
-Event.register(defines.events.on_robot_mined_entity, entity_destroyed)
+Event.add(defines.events.on_robot_mined_entity, entity_destroyed)
-Event.register(defines.events.on_entity_died, entity_destroyed)
+Event.add(defines.events.on_entity_died, entity_destroyed)
-Event.register(defines.events.on_built_entity, entity_build)
+Event.add(defines.events.on_built_entity, entity_build)
-Event.register(defines.events.on_robot_built_entity, entity_build)
+Event.add(defines.events.on_robot_built_entity, entity_build)

score.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 if not global.score_rockets_launched then global.score_rockets_launched = 0 end
 
 local function create_score_gui(event)
@@ -92,7 +94,7 @@ end
 
 
 
-Event.register(defines.events.on_entity_died, refresh_score)
+Event.add(defines.events.on_entity_died, refresh_score)
-Event.register(defines.events.on_gui_click, on_gui_click)
+Event.add(defines.events.on_gui_click, on_gui_click)
-Event.register(defines.events.on_player_joined_game, create_score_gui)
+Event.add(defines.events.on_player_joined_game, create_score_gui)
-Event.register(defines.events.on_rocket_launched, rocket_launched)
+Event.add(defines.events.on_rocket_launched, rocket_launched)

spawn_control.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 global.player_spawns = {} -- player_index to spawn_name
 global.spawns = {} -- spawn_name to x, y, player_online_count
 
@@ -243,9 +245,9 @@ local function print_players_for_spawn_command(cmd)
     print_players_for_spawn(ps[1])
 end
 
-Event.register(defines.events.on_player_joined_game, player_joined_game)
+Event.add(defines.events.on_player_joined_game, player_joined_game)
-Event.register(defines.events.on_player_left_game, player_left_game)
+Event.add(defines.events.on_player_left_game, player_left_game)
-Event.register(defines.events.on_player_respawned, player_respawned)
+Event.add(defines.events.on_player_respawned, player_respawned)
 
 commands.add_command("tpspawn", "<player> <spawn_name> teleports a player to the spawn point (Admins only)", tp_spawn_command)
 commands.add_command("changespawn", "<player> <spawn_name> changes the spawn point for a player (Admins only)", change_spawn_command)

tasklist.lua

@@ -3,6 +3,8 @@
 -- based on MewMew's Poll
 ----------------------------------------------------------------------------------------------------------------------------------------
 
+local Event = require "utils.event"
+
 local function create_tasklist_gui(event)
    local player = game.players[event.player_index]
 
@@ -199,6 +201,6 @@ local function on_gui_click(event)
    end
 end
 
-Event.register(defines.events.on_gui_click, on_gui_click)
+Event.add(defines.events.on_gui_click, on_gui_click)
-Event.register(defines.events.on_player_joined_game, create_tasklist_gui)
+Event.add(defines.events.on_player_joined_game, create_tasklist_gui)
-Event.register(defines.events.on_player_joined_game, tasklist_sync_for_new_joining_player)
+Event.add(defines.events.on_player_joined_game, tasklist_sync_for_new_joining_player)

train_station_names.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 local function player_built_entity(event)
 
 	if event.created_entity.name == "train-stop" then
@@ -13,5 +15,5 @@ local function player_built_entity(event)
 	
 end
 
-Event.register(defines.events.on_built_entity, player_built_entity)
+Event.add(defines.events.on_built_entity, player_built_entity)
-Event.register(defines.events.on_robot_built_entity, player_built_entity)
+Event.add(defines.events.on_robot_built_entity, player_built_entity)

utils/Task.lua

@@ -6,6 +6,7 @@
 
 local Queue = require "utils.Queue"
 local PriorityQueue = require "utils.PriorityQueue"
+local Event = require "utils.event"
 
 local Task = {}
 
@@ -76,6 +77,6 @@ function Task.queue_task(func_name, params, weight)
   Queue.push(global.task_queue, {func_name = func_name, params = params, weight = weight})
 end
 
-Event.register(defines.events.on_tick, on_tick)
+Event.add(defines.events.on_tick, on_tick)
 
 return Task

utils/event.lua

@@ -1,131 +1,152 @@
---Event Capture
+local Event = {}
---A 3Ra Gaming revision, original from Factorio-Stdlib by Afforess
--- @module Event
 
-function fail_if_missing(var, msg)
+local debug_mode = false
-	if not var then
+
-		if msg then
+local init_event_name = -1
-			error(msg, 3)
+local load_event_name = -2
-		else
+
-			error("Missing value", 3)
+local control_stage = true
-		end
+
-	end
+local event_handlers = {}-- map of event_name to handlers[]
-	return false
+local on_nth_tick_event_handlers = {}-- map of nth_tick to handlers[]
+
+local function call_handlers(handlers, event)
+    if debug_mode then
+        for _, handler in ipairs(handlers) do
+            handler(event)
+        end
+    else
+        for _, handler in ipairs(handlers) do
+            local success, error = pcall(handler, event)
+            if not success then
+                log(error)
+            end
+        end
+    end
 end
 
-
+local function on_event(event)
-Event = {
+    local handlers = event_handlers[event.name]
-	_registry = {},
+    call_handlers(handlers, event)
-	core_events = {
-		init = -1,
-		load = -2,
-		configuration_changed = -3,
-		_register = function(id)
-			if id == Event.core_events.init then
-				script.on_init(function()
-					Event.dispatch({ name = Event.core_events.init, tick = game.tick })
-				end)
-			elseif id == Event.core_events.load then
-				script.on_load(function()
-					Event.dispatch({ name = Event.core_events.load, tick = -1 })
-				end)
-			elseif id == Event.core_events.configuration_changed then
-				script.on_configuration_changed(function(data)
-					Event.dispatch({ name = Event.core_events.configuration_changed, tick = game.tick, data = data })
-				end)
-			end
-		end
-	}
-}
-
---- Registers a function for a given event
--- @param event or array containing events to register
--- @param handler Function to call when event is triggered
--- @return #Event
-function Event.register(event, handler)
-	fail_if_missing(event, "missing event argument")
-
-	if type(event) == "number" then
-		event = { event }
-	end
-
-	for _, event_id in pairs(event) do
-		fail_if_missing(event_id, "missing event id")
-		if handler == nil then
-			Event._registry[event_id] = nil
-			script.on_event(event_id, nil)
-		else
-			if not Event._registry[event_id] then
-				Event._registry[event_id] = {}
-
-				if event_id >= 0 then
-					script.on_event(event_id, Event.dispatch)
-				else
-					Event.core_events._register(event_id)
-				end
-			end
-			table.insert(Event._registry[event_id], handler)
-		end
-	end
-	return Event
 end
 
---- Calls the registerd handlers
+local function on_init()
--- @param event LuaEvent as created by game.raise_event
+    local handlers = event_handlers[init_event_name]
-function Event.dispatch(event)
+    call_handlers(handlers)
-	fail_if_missing(event, "missing event argument")
-	if Event._registry[event.name] then
-		for _, handler in pairs(Event._registry[event.name]) do
-			local metatbl = { __index = function(tbl, key) if key == '_handler' then return handler else return rawget(tbl, key) end end }
-			setmetatable(event, metatbl)
-			local success, err = pcall(handler, event)
-			if not success then
-				-- may be nil in on_load
-				local identifier = event.name
-				for i,v in pairs(defines.events) do
-					if v == event.name then
-						identifier = i
-					end
-				end
-				err = string.gsub(err, "\n", " : ")
-				if event.name < -1 or global.last_error ~= identifier then
-					print("output$Error in event "..identifier..": \""..err.."\".")
-					log("Error in event "..identifier..": \""..err.."\".")
-					if event.name > -2 then
-						global.last_error = identifier
-					end
-				end
-			end
-		end
-	end
 end
 
---- Removes the handler from the event
+local function on_load()
--- @param event event or array containing events to remove the handler
+    local handlers = event_handlers[load_event_name]
--- @param handler to remove
+    call_handlers(handlers)
--- @return #Event
-function Event.remove(event, handler)
-	fail_if_missing(event, "missing event argument")
-	fail_if_missing(handler, "missing handler argument")
-
-	if type(event) == "number" then
-		event = { event }
-	end
-
-	for _, event_id in pairs(event) do
-		fail_if_missing(event_id, "missing event id")
-		if Event._registry[event_id] then
-			for i = #Event._registry[event_id], 1, -1 do
-				if Event._registry[event_id][i] == handler then
-					table.remove(Event._registry[event_id], i)
-				end
-			end
-			if #Event._registry[event_id] == 0 then
-				Event._registry[event_id] = nil
-				script.on_event(event_id, nil)
-			end
-		end
-	end
-	return Event
 end
+
+local function on_nth_tick_event(event)
+    local handlers = on_nth_tick_event_handlers[event.nth_tick]
+    call_handlers(handlers, event)
+end
+
+function Event.add(event_name, handler)
+    local handlers = event_handlers[event_name]
+    if not handlers then
+        event_handlers[event_name] = {handler}
+        script.on_event(event_name, on_event)
+    else
+        table.insert(handlers, handler)
+    end
+end
+
+function Event.on_init(handler)
+    local handlers = event_handlers[init_event_name]
+    if not handlers then
+        event_handlers[init_event_name] = {handler}
+        script.on_init(on_init)
+    else
+        table.insert(handlers, handler)
+    end
+end
+
+function Event.on_load(handler)
+    local handlers = event_handlers[load_event_name]
+    if not handlers then
+        event_handlers[load_event_name] = {handler}
+        script.on_load(on_load)
+    else
+        table.insert(handlers, handler)
+    end
+end
+
+function Event.on_nth_tick(tick, handler)
+    local handlers = on_nth_tick_event_handlers[tick]
+    if not handlers then
+        on_nth_tick_event_handlers[tick] = {handler}
+        script.on_nth_tick(tick, on_nth_tick_event)
+    else
+        table.insert(handlers, handler)
+    end
+end
+
+local Token = require "utils.global_token"
+global.event_tokens = {}
+
+function Event.add_removable(event_name, token)
+    local event_tokens = global.event_tokens
+    
+    local tokens = event_tokens[event_name]
+    if not tokens then
+        event_tokens[event_name] = {token}
+    else
+        table.insert(tokens, token)
+    end
+    
+    if not control_stage then
+        local handler = Token.get(token)
+        Event.add(event_name, handler)
+    end
+end
+
+local function remove(t, e)
+    for i, v in ipairs(t) do
+        if v == e then
+            table.remove(t, i)
+            break
+        end
+    end
+end
+
+function Event.remove_removable(event_name, token)
+    local event_tokens = global.event_tokens
+    
+    local tokens = event_tokens[event_name]
+    
+    if not tokens then
+        return
+    end
+    
+    local handler = Token.get(token)
+    local handlers = event_handlers[event_name]
+    
+    remove(tokens, token)
+    remove(handlers, handler)
+    
+    if #handlers == 0 then
+        script.on_event(event_name, nil)
+    end
+end
+
+local function add_token_handlers()
+	control_stage = false
+
+    local event_tokens = global.event_tokens
+    
+    for event_name, tokens in pairs(event_tokens) do
+        for _, token in ipairs(tokens) do
+            local handler = Token.get(token)
+            Event.add(event_name, handler)
+        end
+    end
+end
+
+Event.on_init(add_token_handlers)
+Event.on_load(add_token_handlers)
+
 return Event

utils/global_token.lua

@@ -0,0 +1,20 @@
+local Token = {}
+
+local tokens = {}
+
+local counter = 1
+
+function Token.register(var)
+    local c = counter
+
+    tokens[c] = var
+    counter = c + 1
+
+    return c
+end
+
+function Token.get(token_id)
+    return tokens[token_id]
+end
+
+return Token

utils/utils.lua

@@ -3,6 +3,8 @@
 -- define debug_status to 1 or nil in the control.lua, before statement require("utils")
 -- define also debug_file and debug_mod_name
 
+local Event = require "utils.event"
+
 colors = {
 	white = { r = 1, g = 1, b = 1 },
 	black = { r = 0, g = 0, b = 0 },
@@ -494,7 +496,7 @@ function print_admins(msg)
 		end
 	end
 end
-
+--[[ 
 function check_name(function_name)
 	for i,v in pairs(global.scenario.custom_functions) do
 		if v.name == function_name:lower() then
@@ -511,7 +513,7 @@ function add_global_event(event, func, name)
 	if not name then p("Missing name parameter") return end
 	if check_name(name) then p("Function name \""..name.."\" already in use.") return end
 	table.insert(global.scenario.custom_functions, {event = event, name = name, func = func})
-	Event.register(event, func)
+	Event.add(event, func)
 end
 
 function remove_global_event(name)
@@ -524,8 +526,9 @@ function remove_global_event(name)
 	end
 end
 
-Event.register(-2, function()
+Event.add(-2, function()
 	for i,v in pairs(global.scenario.custom_functions) do
-		Event.register(v.event, v.func)
+		Event.add(v.event, v.func)
 	end
 end)
+ ]]

walk_distance.lua

@@ -1,3 +1,5 @@
+local Event = require "utils.event"
+
 function walk_distance_on_second()
   local last_positions = global.scenario.variables.player_positions
   local d_x = 0
@@ -30,4 +32,4 @@ local function init_player_position(event)
   end
 end
 
--- Event.register(defines.events.on_player_joined_game, init_player_position)
+-- Event.add(defines.events.on_player_joined_game, init_player_position)