Difference between revisions of "Module:No globals"
Dinoguy1000 (talk | contribs) (from wikipedia:Module:No globals) |
Dinoguy1000 (talk | contribs) m (1 revision: try importing instead of hand-copying) |
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Revision as of 21:44, 17 February 2015
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 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.)
Module documentationrequire('Module:No globals')
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)
