README.md: Return from example fold methods (#8)

Use mod.conf for description / remove extra whitespace / give monoid_master privilege to admin

.luacheckrc

@@ -0,0 +1,9 @@
+
+read_globals = {
+	"minetest",
+	"vector",
+}
+
+globals = {
+	"player_monoids",
+}

README.md

@@ -40,9 +40,10 @@ mymod.speed_monoid = player_monoids.make_monoid({
 	end,
 	fold = function(tab)
 		local res = 1
-	     	for _, speed in pairs(tab) do
+		for _, speed in pairs(tab) do
 			res = res * speed
-	     	end
+		end
+		return res
 	end,
 	identity = 1,
 	apply = function(speed, player)
@@ -104,13 +105,14 @@ the strongest boost. Most of it could be done the same way:
 -- My speed boosts monoid takes speed multipliers (numbers) that are at least 1.
 newmod.speed_boosts = player_monoids.make_monoid({
 	combine = function(speed1, speed2)
-		return speed1 * speed2
+		return math.max(speed1, speed2)
 	end,
 	fold = function(tab)
 		local res = 1
-	     	for _, speed in pairs(tab) do
+		for _, speed in pairs(tab) do
-			res = res * speed
+			res = math.max(res, speed)
-	     	end
+		end
+		return res
 	end,
 	identity = 1,
 	apply = ???
@@ -202,4 +204,4 @@ global state.
 * The order that different effects get combined together is based on key order,
 which may not be predictable. So you should try to make your monoids commutative
 in addition to associative, or at least not care if the order of two changes
-is swapped.
+is swapped.

description.txt

@@ -1,2 +0,0 @@
-player_monoids is a library for managing global player state, such as physics
-overrides or player visual size.

init.lua

@@ -59,13 +59,13 @@ local function monoid(def)
 	return mon
 end
 
-player_monoids.monoid = monoid
+player_monoids.make_monoid = monoid
 
-function mon_meta:add_change(player, value)
+function mon_meta:add_change(player, value, id)
 	local p_name = player:get_player_name()
 
 	local def = self.def
-        
+
 	local p_effects = self.player_map[p_name]
 	if p_effects == nil then
 		p_effects = {}

mod.conf

@@ -1 +1,5 @@
-name=player_monoids
+name = player_monoids
+description = """ 
+A library for managing global player state, 
+such as physics overrides or player visual size.
+"""

standard_monoids.lua

@@ -5,7 +5,7 @@ local function mult(x, y) return x * y end
 local function mult_fold(elems)
 	local tot = 1
 
-	for k,v in pairs(elems) do
+	for _, v in pairs(elems) do
 		tot = tot * v
 	end
 
@@ -26,7 +26,7 @@ local function v_mult_fold(identity)
 	return function(elems)
 		local tot = identity
 
-		for k, v in pairs(elems) do
+		for _, v in pairs(elems) do
 			tot = v_mult(tot, v)
 		end
 
@@ -34,24 +34,17 @@ local function v_mult_fold(identity)
 	end
 end
 
-local monoid = player_monoids.monoid
+local monoid = player_monoids.make_monoid
 
 -- Speed monoid. Effect values are speed multipliers. Must be nonnegative
 -- numbers.
 player_monoids.speed = monoid({
-	combine = function(x, y) return x * y end,
+	combine = mult,
-	fold = function(elems)
+	fold = mult_fold,
-		local res = 1
-		for k, v in pairs(elems) do
-			res = res * v
-		end
-
-		return res
-	end,
 	identity = 1,
-	apply = function(mult, player)
+	apply = function(multiplier, player)
 		local ov = player:get_physics_override()
-		ov.speed = mult
+		ov.speed = multiplier
 		player:set_physics_override(ov)
 	end,
 })
@@ -60,50 +53,34 @@ player_monoids.speed = monoid({
 -- Jump monoid. Effect values are jump multipliers. Must be nonnegative
 -- numbers.
 player_monoids.jump = monoid({
-	combine = function(x, y) return x * y end,
+	combine = mult,
-	fold = function(elems)
+	fold = mult_fold,
-		local res = 1
-		for k, v in pairs(elems) do
-			res = res * v
-		end
-
-		return res
-	end,
 	identity = 1,
-	apply = function(mult, player)
+	apply = function(multiplier, player)
 		local ov = player:get_physics_override()
-		ov.jump = mult
+		ov.jump = multiplier
 		player:set_physics_override(ov)
 	end,
 })
 
-
 -- Gravity monoid. Effect values are gravity multipliers.
 player_monoids.gravity = monoid({
-	combine = function(x, y) return x * y end,
+	combine = mult,
-	fold = function(elems)
+	fold = mult_fold,
-		local res = 1
-		for k, v in pairs(elems) do
-			res = res * v
-		end
-
-		return res
-	end,
 	identity = 1,
-	apply = function(mult, player)
+	apply = function(multiplier, player)
 		local ov = player:get_physics_override()
-		ov.gravity = mult
+		ov.gravity = multiplier
 		player:set_physics_override(ov)
 	end,
 })
 
-
 -- Fly ability monoid. The values are booleans, which are combined by or. A true
 -- value indicates having the ability to fly.
 player_monoids.fly = monoid({
 	combine = function(p, q) return p or q end,
 	fold = function(elems)
-		for k, v in pairs(elems) do
+		for _, v in pairs(elems) do
 			if v then return true end
 		end
 
@@ -125,12 +102,11 @@ player_monoids.fly = monoid({
 	end,
 })
 
-
 -- Noclip ability monoid. Works the same as fly monoid.
 player_monoids.noclip = monoid({
 	combine = function(p, q) return p or q end,
 	fold = function(elems)
-		for k, v in pairs(elems) do
+		for _, v in pairs(elems) do
 			if v then return true end
 		end
 

test.lua

@@ -4,6 +4,7 @@ local speed = player_monoids.speed
 minetest.register_privilege("monoid_master", {
 	description = "Allows testing of player monoids.",
 	give_to_singleplayer = false,
+	give_to_admin = true,
 })
 
 local function test(player)
@@ -11,8 +12,10 @@ local function test(player)
 	local p_name = player:get_player_name()
 
 	minetest.chat_send_player(p_name, "Your speed is: " .. speed:value(player))
-	
+
 	minetest.after(3, function()
+		local player = minetest.get_player_by_name(p_name)
+		if not player then return end
 		speed:del_change(player, ch_id)
 		minetest.chat_send_player(p_name, "Your speed is: " .. speed:value(player))
 	end)