Related
My goal is to create a script that warns when you are disenchanting a piece you don't want. When disenchanting an item straight from inventory, I could use the UseInventoryItem() API. Since UseInventoryItem() seems to work only on inventory slot right click, I created this script, based on GetMouseFocus() API, that works with the original interface of the game: but if someone used an addon, would it still work?
Of course, better solutions are welcome
local mt = {
__index = {
isvalue = function(t, value)
local is = false
for k, entry in ipairs(t) do
if (entry == value) then
is = true
break
end
end
return is
end
}
};
local protected = { "item1", "item2", "item3", "etch." }; -- items I want to protect
setmetatable(protected, mt);
local disenchanting;
local antidisenchant = CreateFrame("Frame");
antidisenchant:RegisterEvent("UNIT_SPELLCAST_SENT");
antidisenchant:SetScript("OnEvent", function(self, event, ...)
if (event == "UNIT_SPELLCAST_SENT") then
if (arg2 == "Disenchant") then
disenchanting = true
end
end
end);
antidisenchant:SetScript("OnUpdate", function()
if GetMouseFocus() then -- GetMouseFocus() returns the frame that currently has mouse focus.
local TargetItemID = GetInventoryItemID("player",GetMouseFocus():GetID()) -- The IDs of each inventory slot frame have the same id as the slot (16 for main hand, 17 for off hand etc.).
if (TargetItemID) and (string.find(GetMouseFocus():GetName(),"Slot")) then -- Inventory slot frame are named like "CharacterMainHandSlot".
local name, link = GetItemInfo(TargetItemID)
if (disenchanting) and (protected:isvalue(name)) then
DEFAULT_CHAT_FRAME:AddMessage("WARNING! YOU'RE DISENCHANTING "..link,1,0,0)
end
end
end
end)
I'm trying to implement a speed-based turn system for a roguelike. I've set up a Mob class using metamethods, so that assigning the following to a variable will spawn a mob into the map at certain grid coordinates:
function Mob:spawn(x,y,m)
local mob = {}
setmetatable(mob, Mob)
mob.x = x
mob.y = y
mob.is_monster = m
return mob
end
Once that's done, I call the following:
function Mob:roll_call()
who_is_here[self.y][self.x] = self.is_monster
self.turn_counter = self.turn_counter * math.random(0.9, 1.1)
table.insert(allTurnCounters, self.turn_counter)
end
This puts the mob's self.turn_counter into a table. Meanwhile, in another module, I've defined these two functions, the heart of the problem:
function turn.decrement_counters(dt) -- runs in Dungeon.update(dt) and subtracts from allTurnCounters
for i = 1,#allMobsSpawned do
if allTurnCounters[i] <= 0 then
allTurnCounters[i] = 0
turn_active = true
whose_turn = i
return
elseif allTurnCounters[i] > 0 then
allTurnCounters[i] = allTurnCounters[i] - (10 * dt)
end
end
end
function turn.whose_is_it() -- called when an entry in allTurnCounters goes zero
if whose_turn == 1 then -- spots 1 and 2 in the spawn list are only ever for players
player1.my_turn = true -- turns on player 1's keys
elseif whose_turn == 2 then
player2.my_turn = true -- turns on player 2's keys
elseif whose_turn >= 3 then -- above 3 we're in monster territory
end
end
I've decided that the first two instances of Mob to be initialized will always be players 1 and 2, assigned to the variables player1 and player2, respectively. And, as it is, it works fine for passing control back and forth between players! But obviously, that's not enough for a fully-featured game. I need monsters, too.
The allTurnCounters table gets new entries, in order, from every mob that spawns (a class which includes both the players and the monsters, so they can share stats). Here's my question: How can I get Lua to dynamically retrieve the name of the table associated with a given turn_counter/value within that table, and use it to take turn priority, even in the event that I don't know what's been procedurally spawned ahead of time or what place it will occupy in the spawn order?
I have 3 ideas, none of which I'm solid on how to implement. One method would be something like sending the entire instance table to another table, rather than just their turn_counters, and then somehow grabbing a pair of values (the table itself and my_turn within the table), updating my_turn's value directly.
Another method might be to use the environment _G... somehow. I'm still poring over Chapter 14 of PiL trying to adapt it to my purposes, but value = _G[varname] seems to be a powerful bit of code I might be able to use for this. Not sure how, just yet.
My last idea was to maybe write some kind of string-sensing find-replace that can grab some other value in each mob's table and then pop it on the front of my_turn. Like, assigning some value with a known pattern for each mob type, that I can use in a string.find and then a string.gsub, to like... manually make the code line read as intended. Seems inelegant, though.
I had good luck with asking my previous Lua/Love2D question here, so I figured let's toss it out there while I'm thinking!
Here is my suggestion for how you should implement this:
Instead of allTurnCounters[i], give mobs a turn_counter property and use allMobsSpawned[i].turn_counter. Then, delete allTurnCounters.
Instead of storing the mob number in whose_turn, store the mob itself. (Note: when I say "the mob itself", it's short for "a reference to the mob itself")
So instead of
whose_turn = i
you would have:
whose_turn = allMobsSpawned[i]
Now whose_turn holds the mob whose turn it is. You can easily check whose_turn == player1, whose_turn == player2, etc. As a bonus, it doesn't rely on the players being the first mobs any more.
You can access the mob's properties through whose_turn - if whose_turn == player1 is true for example then whose_turn.x accesses the same field as player1.x
Here's a somewhat janky solution that can be made more elegant by incorporating the method from the other answer. This is what I came up with on my own while waiting for an answer.
-- in "Mob.lua" module
function Mob:roll_call()
who_is_here[self.y][self.x] = self.is_monster
self.turn_counter = self.turn_counter * math.random(0.9, 1.1)
table.insert(allMobs, {self.name, self.turn_counter})
if self.is_monster == true then
table.insert(allMonsters, {self.name, self.turn_counter})
end
end
function Mob:move(dx, dy)
who_is_here[self.y][self.x] = nil
self.x, self.y = self.x + dx, self.y + dy
who_is_here[self.y][self.x] = self.is_monster
self.turn_counter = 1 * self.speed
for k,v in ipairs(allMobs) do
if v[1] == self.name then
v[2] = self.turn_counter
end
end
self.my_turn = false -- flags turn is over
turn_active = false -- flags no active turn
end
-- in "turn.lua" module
function turn.decrement_counters(dt)
if turn_active == false then
for k,v in ipairs(allMobs) do
v[2] = v[2] - (10 * dt)
if v[2] < 0 then
v[2] = 0
turn_active = true
whose_turn = v[1]
return
end
end
else turn.whose_is_it()
end
end
function turn.whose_is_it()
if whose_turn == player1.name then
player1.my_turn = true
elseif whose_turn == player2.name then
player2.my_turn = true
elseif whose_turn == ant1.name then
ant1.my_turn = true
end
end
turn.whose_is_it() is the part that will need refining. If I use immibis' method of assigning allMobs[i].turn_counter, that will simplify things considerably and allow for future expansion. This answer only works for player1, player2, and an ant called ant1 in particular.
i have a problem (obviusly :P)
i'm create a mini game, and when i touch a Object-A , creates an Object-B.
If i touch N times, this create N Object-B.
(Object-B are Bubbles in my game)
so, i try when I touch the bubble (object-B), that disappears or perform any actions.
I try adding Object-B to Array
local t = {}
.
.
.
bur = display.newImage("burbuja.png")
table.insert(t,bur)
and where i have my eventListeners i wrote:
for i=1, #t do
bur[i]:addEventListener("tap",reventar(i))
end
and my function 'reventar'
local function reventar (event,id)
table.remove(t,id)
end
i'm lost, and only i want disappears the bubbles.
you're probably gonna want to do something like this:
local t = {}
bur = display.newImage("burbuja.png")
table.insert(t,bur)
-- declaring the function first so it can be used later in the for loop
local function reventar(event)
t[event.target.id] = nil -- We remove object from table
event.target:removeSelf() -- Also remember to remove from display
end
for i=1,#t do
t[i].id = i
t[i]:addEventListener("tap", reventar)
end
Hope this helps.
EDIT
I would do it this way, because it's better when you want to loop through the objects:
local t = {}
-- declaring the function first so it can be used later
local function reventar(event)
event.target.kill = true -- Mark the clicked object for later destruction
end
bur = display.newImage("burbuja.png")
bur:addEventListener("tap", reventar)
table.insert(t,bur)
local function loop(event)
for i = #t, 1, -1 do
local object = t[i]
-- Do stuff to object here, such as object.y = object.y + 1
if object.kill then -- Check if object is marked for destruction
local child = table.remove(t, i) -- Remove from table
if child ~= nil then
-- Remove from display and nil it
child:removeSelf()
child = nil
end
end
end
end
Runtime:addEventListener("enterFrame", loop) -- Remember to remove this when no longer needed
I'm attempting to compare two tables of equal length with a function, since I don't know of any other way to do so. However, with the following function, it fails to register, and I've no clue why. I'm hoping someone can provide insight to this problem or has a better way of comparing the two tables.
The tables are being populated with the following code:
str = "parameters determined by program (all digits)"
tableone = {}
for word in str:gmatch("%d") do table.insert(tableone,word) end
It's identical for both tables, except, of course, the individual table names. The tables are being populated properly, and display properly when I print them. Here are two tables for the sake of this question:
tableone = {}
tabletwo = {}
for i=1,4 do table.insert(tableone, i) end
for i=1,4 do table.insert(tabletwo, i) end
Obviously, these two tables are going to be equal to each other. The function I wrote to compare the index tables is as follows:
function comparetables(t1, t2)
matchct = 0
for i=1,#t1 do
if t1[i] == t2[i] then
matchct = matchct + 1
end
if matchct == #t1 then
return true
end
end
I tried doing
print(comparetables(tableone,tabletwo))
to see if it'll print "true" but no luck. To me, it seems like it should work without a problem. Yet it doesn't. What am I missing? I've tried searching for something like a table.compare function that someone may have already written, but no such luck in finding one. Thanks for any suggestions!
Additional information:
The reason I'm comparing tables is for a mastermaind-type game. That means the following three rules must apply when comparing tables. The function I created was to just get me started, thinking I could work from there.
When comparing the tables, if the numbers match, Ccount increases by 1.
When comparing tables, if the value exists in a different index position, increment Pcount by 1
For example, with a table of values {1, 3, 3, 4} and a guess of {4, 4, 3, 1}, it would return Pcount of 2 (the one 4 and the 1) and a Ccount of 1 (the three in the third position). I think one of the hardest parts is going to be getting the comparison to recognize that the second 4 in the guess should not increment the Pcount at all.
A slight variant on your code that should work is:
function comparetables(t1, t2)
if #t1 ~= #t2 then return false end
for i=1,#t1 do
if t1[i] ~= t2[i] then return false end
end
return true
end
However I use something more like this: It checks the types of the arguments, their metatables, and a few other cases.
-- This is not clever enough to find matching table keys
-- i.e. this will return false
-- recursive_compare( { [{}]:1 }, { [{}]:1 } )
-- but this is unusual enough for me not to care ;)
-- It can also get stuck in infinite loops if you use it on
-- an evil table like this:
-- t = {}
-- t[1] = t
function recursive_compare(t1,t2)
-- Use usual comparison first.
if t1==t2 then return true end
-- We only support non-default behavior for tables
if (type(t1)~="table") then return false end
-- They better have the same metatables
local mt1 = getmetatable(t1)
local mt2 = getmetatable(t2)
if( not recursive_compare(mt1,mt2) ) then return false end
-- Check each key-value pair
-- We have to do this both ways in case we miss some.
-- TODO: Could probably be smarter and not check those we've
-- already checked though!
for k1,v1 in pairs(t1) do
local v2 = t2[k1]
if( not recursive_compare(v1,v2) ) then return false end
end
for k2,v2 in pairs(t2) do
local v1 = t1[k2]
if( not recursive_compare(v1,v2) ) then return false end
end
return true
end
Here's an example of it in use:
print( recursive_compare( {1,2,3,{1,2,1}}, {1,2,3,{1,2,1}} ) ) -- prints true
print( recursive_compare( {1,2,3,{1,2,1}}, {2,2,3,{1,2,3}} ) ) -- prints false
If you're comparing objects that are more objecty than tabley in an Object oriented sense, then I'd look at implementing the functions in the lua OO way.
Something like this should do the trick:
GameState = {}
GameState.mt = {}
GameState.mt.fns = {}
GameState.mt.__index = GameState.mt.fns
function GameState.new(a,b,c,d)
-- TODO: put argument checks here...
local retval = {}
retval[1] = a
retval[2] = b
retval[3] = c
retval[4] = d
setmetatable(retval, GameState.mt)
return retval
end
function GameState.mt.fns.print( self )
print(" GameState: ", self[1], self[2], self[3], self[4] )
end
function GameState.mt.__tostring( self )
return "GameState: "..self[1].." "..self[2].." "..self[3].." "..self[4]
end
function GameState.mt.__eq(self, other)
-- Check it's actually a GameState, and all its bits match
return getmetatable(other)==GameState.mt and
(self[1] == other[1]) and
(self[2] == other[2]) and
(self[3] == other[3]) and
(self[4] == other[4])
end
Then you'd use it like this:
state1 = GameState.new(1,2,3,4)
state2 = GameState.new(1,2,3,4)
print("State 1 is:")
state1:print()
print("State 2 is:")
print(state2)
print( "state1 == state2 : ", state1 == state2 )
print( "Changing state 2")
state2[1]=2
print( "state1 == state2 : ", state1 == state2 )
I'm trying, as an exercise, to make a set implementation in Lua. Specifically I want to take the simplistic set implementation of Pil2 11.5 and grow it up to include the ability to insert values, delete values, etc.
Now the obvious way to do this (and the way that works) is this:
Set = {}
function Set.new(l)
local s = {}
for _, v in ipairs(l) do
s[v] = true
end
return s
end
function Set.insert(s, v)
s[v] = true
end
ts = Set.new {1,2,3,4,5}
Set.insert(ts, 5)
Set.insert(ts, 6)
for k in pairs(ts) do
print(k)
end
As expected I get the numbers 1 through 6 printed out. But those calls to Set.insert(s, value) are really rather ugly. I'd much rather be able to call something like ts:insert(value).
My first attempt at a solution to this looked like this:
Set = {}
function Set.new(l)
local s = {
insert = function(t, v)
t[v] = true
end
}
for _, v in ipairs(l) do
s[v] = true
end
return s
end
ts = Set.new {1,2,3,4,5}
ts:insert(5)
ts:insert(6)
for k in pairs(ts) do
print(k)
end
This works mostly fine until you see what comes out of it:
1
2
3
4
5
6
insert
Very obviously the insert function, which is a member of the set table, is being displayed. Not only is this even uglier than the original Set.insert(s, v) problem, it's also prone to some serious trouble (like what happens if "insert" is a valid key someone is trying to enter?). It's time to hit the books again. What happens if I try this instead?:
Set = {}
function Set.new(l)
local s = {}
setmetatable(s, {__call = Set.call})
for _, v in ipairs(l) do
s[v] = true
end
return s
end
function Set.call(f)
return Set[f]
end
function Set.insert(t, v)
t[v] = true
end
ts = Set.new {1,2,3,4,5}
ts:insert(5)
ts:insert(6)
for k in pairs(ts) do
print(k)
end
Now the way I'm reading this code is:
When I call ts:insert(5), the fact that insert doesn't exist to be called means that the ts metatable is going to be searched for "__call".
The ts metatable's "__call" key returns Set.call.
Now Set.call is called with the name insert which causes it to return the Set.insert function.
Set.insert(ts, 5) is called.
What's really happening is this:
lua: xasm.lua:26: attempt to call method 'insert' (a nil value)
stack traceback:
xasm.lua:26: in main chunk
[C]: ?
And at this point I'm stumped. I have absolutely no idea where to go from here. I hacked around for an hour with varying degrees of increasingly desperate variations on this code but the end result is that I have nothing that works. What undoubtedly obvious thing am I overlooking at this point?
Now the way I'm reading this code is:
When I call ts:insert(5), the fact that insert doesn't exist to be called means that the ts metatable is going to be searched for "__call".
There's your problem. The __call metamethod is consulted when the table itself is called (ie, as a function):
local ts = {}
local mt = {}
function mt.__call(...)
print("Table called!", ...)
end
setmetatable(ts, mt)
ts() --> prints "Table called!"
ts(5) --> prints "Table called!" and 5
ts"String construct-call" --> prints "Table called!" and "String construct-call"
Object-oriented colon-calls in Lua such as this:
ts:insert(5)
are merely syntactic sugar for
ts.insert(ts,5)
which is itself syntactic sugar for
ts["insert"](ts,5)
As such, the action that is being taken on ts is not a call, but an index (the result of ts["insert"] being what is called), which is governed by the __index metamethod.
The __index metamethod can be a table for the simple case where you want indexing to "fall back" to another table (note that it is the value of the __index key in the metatable that gets indexed and not the metatable itself):
local fallback = {example = 5}
local mt = {__index = fallback}
local ts = setmetatable({}, mt)
print(ts.example) --> prints 5
The __index metamethod as a function works similarly to the signature you expected with Set.call, except that it passes the table being indexed before the key:
local ff = {}
local mt = {}
function ff.example(...)
print("Example called!",...)
end
function mt.__index(s,k)
print("Indexing table named:", s.name)
return ff[k]
end
local ts = {name = "Bob"}
setmetatable(ts, mt)
ts.example(5) --> prints "Indexing table named:" and "Bob",
--> then on the next line "Example called!" and 5
For more information on metatables, consult the manual.
You said:
Now the way I'm reading this code is:
When I call ts:insert(5), the fact that insert doesn't
exist to be called means that the ts metatable is going
to be searched for "__call".
The ts metatable's "__call" key returns Set.call.
Now Set.call is called with the name insert which causes
it to return the Set.insert function.
Set.insert(ts, 5) is called.
No, what happens is this:
When insert isn't found directly in the ts object, Lua looks for __index in its metatable.
If it is there and it is a table, Lua will search for insert there.
If it is there and it is a function, it will call it with the original table (ts in this case) and the key being searched for (insert).
If it isn't there, which is the case, it is considered nil.
The error you're having is because you don't have __index set in your metatable, so you are effectively calling a nil value.
This can be solved by pointing __index to some table, namely Set, if you're going to store your methods there.
As for __call, it is used for when you call the object as a function. Ie:
Set = {}
function Set.new(l)
local s = {}
setmetatable(s, {__index=Set, __call=Set.call})
for _, v in ipairs(l) do
s[v] = true
end
return s
end
function Set.call(s, f)
-- Calls a function for every element in the set
for k in pairs(s) do
f(k)
end
end
function Set.insert(t, v)
t[v] = true
end
ts = Set.new {1,2,3,4,5}
ts:insert(5)
ts:insert(6)
ts(print) -- Calls getmetatable(ts).__call(ts, print),
-- which means Set.call(ts, print)
-- The way __call and __index are set,
-- this is equivalent to the line above
ts:call(print)
Set = {}
function Set.new(l)
local s = {}
setmetatable(s, {__index=Set})
for _, v in ipairs(l) do
s[v] = true
end
return s
end
function Set.call(f)
return Set[f]
end
function Set.insert(t, v)
t[v] = true
end
ts = Set.new {1,2,3,4,5}
ts:insert(5)
ts:insert(6)
for k in pairs(ts) do
print(k)
end
I modified your first version and this version would offer the features I think you are looking for.
Set = {}
Set.__index = Set
function Set:new(collection)
local o = {}
for _, v in ipairs(collection) do
o[v] = true
end
setmetatable(o, self)
return o
end
function Set:insert(v)
self[v] = true
end
set = Set:new({1,2,3,4,5})
print(set[1]) --> true
print(set[10]) --> nil
set:insert(10)
print(set[10]) --> true