Ok, well let’s take a trivial and contrived example of a UI configuration. The configuration might look something like this:
UI = {
mainwindow = {
size = {
width = 100,
height = 200
}
}
}
Now, my code wants to use this information very simply:
local width = config.UI.mainwindow.size.width
But before I can do that, as a minimum I need to verify the structure and format of the config before I can safely use it. Very naively, I might do something like this:
local width
if type(UI) == ’table’ then
if type(UI.mainwindow) == ’table’ then
if type(UI.mainwindow.size) == ’table’ then
— now can access safely
width = UI.mainwindow.size.width
end
end
end
I can't find the thread now but I think Luiz suggested a technique like:
debug.setmetatable(nil,{__index = function(t,k) return nil end})
now you can just do
t = {}
t.x -- nil
t.x.a -- nil
t.x.a.b -- nil
So now you can just load the config and do:
width = UI.mainwindow.size.width or 23 (or whatever is the default)
