Cheat Engine

[Dr.Disrespect]

I am reading some LUA codes from an addon for World of Warcraft. I don't understand the following:

First,

[ParkourPenguin]

The first is copying global (maybe upvalue) variables to local variables. This could be a minor optimization in a critical part of the code.

The second is the closest thing Lua has to a ternary conditional operator. The "and" and "or" operators short-circuit: if the first operand to "and" / "or" evaluates to false / true respectively, the expression will return the first operand and the second operand will not be evaluated.
That code is equivalent to this:

[atom0s]

First one is generally either done for one of two reasons:

1. The vars are within a module.
2. The vars are used to make ease of calling of a function.

In your case, it looks more like the first, or just bad coding in general. When you define a module in Lua, the globals are moved into your modules table, meaning that they technically 'break' for normal usage. More info on that: http://lua-users.org/wiki/LuaModuleFunctionCritiqued

Module creation like this shouldn't be used anymore though since it is deprecated at this point.

[Dr.Disrespect]

Thank you Penguin and atom0s for the explanations.

+rep.