Module:No globals

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Revision as of 11:14, 26 January 2016 by LIMAFOX76 (talk | contribs) (Created page with "local mt = getmetatable(_G) or {} function mt.__index (t, k) if k ~= 'arg' then error('Tried to read nil global ' .. tostring(k), 2) end return nil end function mt.__newi...")
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This module causes an error if any nil global is read or if any global is written to, with the exception of arg. To use, add require('Module:No globals') to the top of the module using it. The arg variable is excluded because it is necessary for Scribunto's require function to work properly. (See the Scribunto source code here.)

local mt = getmetatable(_G) or {}
function mt.__index (t, k)
	if k ~= 'arg' then
		error('Tried to read nil global ' .. tostring(k), 2)
	end
	return nil
end
function mt.__newindex(t, k, v)
	if k ~= 'arg' then
		error('Tried to write global ' .. tostring(k), 2)
	end
	rawset(t, k, v)
end
setmetatable(_G, mt)