local is local in a global?

[Torhal]

Originally Posted by nightcracker <snip> The most important part is to not take parameters you don't need in your function. <snip>

The use of "_" instead of "self" is not doing what you think it is. All you're doing is re-naming the parameter, making its origin obscure. You are not eliminating it.

[nightcracker]

Originally Posted by Torhal The use of "_" instead of "self" is not doing what you think it is. All you're doing is re-naming the parameter, making its origin obscure. You are not eliminating it.

I'm sorry, I thought the underscore variable was defined in Lua as a dummy variable. Looked it up, and it's not, although it is a convention.

[Wobin]

Originally Posted by Torhal The use of "_" instead of "self" is not doing what you think it is. All you're doing is re-naming the parameter, making its origin obscure. You are not eliminating it.

Indeed, people think '_' is a magic parameter that instantly discards what it's assigned as. In actuality, it's just another variable name like any other. It's used in common parlance for 'ignored' variables only because it's a nonstandard character, and easy to identify.

On another point, if 'self' is being garbage collected mid function, you've already got problems with your situation... mostly in that the rug just got pulled from under you. Remember, everything is passed in as a -reference-, you're not -really- making a full copy of 'self', so all that is 'wasted' is a local reference. And if a local reference is causing you memory issues, you clearly have more serious problems with your code.

[Seerah]

Originally Posted by nightcracker use function(_,event)

Just to clarify here, you're still creating two variables with the above. _ is a perfectly valid name for a variable. It's just that it's become common practice to use _ as a throwaway variable.


edit: wow... there was a second page (/me needs caffeine)

[SDPhantom]

Originally Posted by nightcracker UIParent:HookScript("OnEvent",function(_,e) e=="DUEL_REQUESTED" and CancelDuel() and StaticPopup_Hide("DUEL_REQUESTED") end)

The problem I see with this code is I'm not sure if CancelDuel() has a return value, which would result as nil and fail to run StaticPopup_Hide(). It's just how Lua processes logical operators to speed up execution time.

Here's an example:

func1() and func2()

If func1() returns nil or false (no return is considered nil), it'll return that value and not call func2(). Otherwise, it'll return the value func2() returns. or works in the same way, only calling and returning func2() if func1() returns an equivalent boolean true.


Another problem I see with the above code and I haven't exactly tested it, is if you have an expression that isn't assigned to a variable or used as an argument in a function call. Lua would throw an error trying to parse the line, expecting an assignment operator. A single function call would be an exception to this rule. A conditional "and/or" line is never a good replacement for an "if...then" block.

Originally Posted by nightcracker The most important part is to not take parameters you don't need in your function. Instead of function(self, event, ...) use function(_,event). If you do take the parameters in your function they get stored in the memory(which is not bad at all), but then comes the garbage collector wasting CPU on what really IS garbage.

As stated in above posts, unused variable references would be the least of your worries when it comes to memory. It's also considered good programming practice to make code as readable as it is functional.

[Rilgamon]

After reading and thinking about it I finally figured where the "fishingpole"
error came from.

addon:AddConfigEntry("toggle",name,desc,_,1)

should have been

addon:AddConfigEntry("toggle",name,desc,nil,1)

Another mystery solved