lua - want to call a function in main.lua from another module

I want a to call a function that is defined in main.lua from a module that is required (included) in main.lua. What's the 开发者_如何学运维best/cleanest way to do this?

Edit:

I eventually went down the dispatch event route. That seems to be a neat way of doing it.

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There are two options as far as I can see:

1. Define the function A first, then require() the module, and call function A there.
2. require() the module first, and have the module define a function B that calls the function A in your main file. Call function B whenever you are ready to call it (i.e. function A is defined) in your main file.

The latter seems cleaner, but that would be a matter of personal preference.

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Move that function to a separate module. This is the cleanest way.

Otherwise, use a global variable to store that function.

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Make it available in the global table. For example:

--main.lua
require "myModule"

myModule.someFunc()

function mainFunc(...)
    --...
end

--myModule.lua
module(myModule)

mainFunc(parameters)

As long as the module doesn't define the same variable name locally (and if it does, you can use _G.mainFunc to get it), you should be fine.