WoWInterface - Ellipses assignment?

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Ellipses assignment?

I've been getting into WoW addon development and for the moment, I'm mainly looking through other people's code to understand what's going on. I keep seeing this type of thing all over the place and I can't, for the life of me, figure out what it means.

local _, ns = ...

They then go on to use the ns variable, but I don't know how it has any data in it. What are they assigning it to exactly?

It's a table that gets passed to all files of an addon

https://wowpedia.fandom.com/wiki/Usi...ddOn_namespace

Sweet, that makes a lot of sense. Thank you!

For a more in-depth explanation, ... in Lua is called a vararg, short for variable arguments. It is used when defining a function when the number of arguments being passed to it is unknown.

Lua Code:

function fooBar(...)
    local test1, test2 = ...
    print(test1, test2)
end
 
fooBar("apple")
fooBar("orange", "banana")

There's another level to WoW's coding we don't see, which is written in C++. When this internal structure loads an addon, each file in the addon is actually one big function.

We see:

Lua Code:

local _, ns = ...
-- rest of our file

What's actually happening:

Lua Code:

function addonFile(...)
    local _, ns = ...
    -- rest of our file
end
 
addonFile("Name of AddOn", privateTable)

This privateTable is shared across all loaded files within an addon, basically each .toc file gets its own table.