Please explain the following code?

Can someone explain the following code:

	local coreCall do
	    local MAX_RETRIES = 8
	 
	    local StarterGui = game:GetService('StarterGui')
	    local RunService = game:GetService('RunService')
	 
	    function coreCall(method, ...)
	        local result = {}
	        for retries = 1, MAX_RETRIES do
	            result = {pcall(StarterGui[method], StarterGui, ...)}
	            if result[1] then
	                break
	            end
	            RunService.Stepped:Wait()
	        end
	        return unpack(result)
	    end
	end
	 
	coreCall('SetCore', 'ResetButtonCallback', false)

Questions I had in particular were:

1) What does local coreCall do mean? Is it simply another way to define a function? Is there a special usecase?

2) Is there a reason why MAX_RETRIES is only set to 8? Wouldn't this mean if it retried 8 times then the desired effect would not occur? Wouldn't it be better to not have a MAX_RETRIES?

Thank you!

##1) That is almost useless do statement, you should not be using it, however you can't hate it as it creates static variables for optimization which is cool. do statements in Lua create new scope preventing variables to be accessed from higher scopes, like this

local A = true

do
	local B = true
end

print(A, B) -- true, nil

In your case he just put do after the variable making it bit more confusing, but he did same thing as this

local coreCall = nil
local coreCall
--\\those 2 are almost identical, however, use the second method.

do
	--/ Only defines this variable once
	local MAX_TRIES = 8

	...

	--/ Not local function, must initialize the coreCall
	--\ variable in the outer scope so you can access
	--\ it outside of the do statement
	function coreCall(...)
		
		repeat ... for MAX_TRIES ...
	end
end

print(MAX_TRIES) -- nil

coreCall(...) -- works

Here you can see that the variable MAX_TRIES is defined once in the do statement and then it will be used by the coreCall function, you can do

local function coreCall(...)
	
	local MAX_TRIES = 8

	repeat ... for MAX_TRIES ...
end

or

local MAX_TRIES = 8

local function coreCall(...)

	repeat ... for MAX_TRIES ...
end

However, the first method would create MAX_TRIES every time you call the function and the second method would flood the scope with unneccessary variable, like you are not going to use MAX_TRIES outside of the coreCall function, this is why it is written with do statement. ##2) The second one is simple, say Roblox disables CoreGui named ResetButtonCallback, if you would not have MAX_TRIES, it will loop infiintely trying to set the core but it will never be able to as Roblox has disabled the method, that's why MAX_TRIES is made, it will loop for 8 times and if it won't work then it's mostly because the CoreGui thing is not enabled.