Module:No globals: Difference between revisions

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m Copying one change by Mainframe98: "From Module:No globals/sandbox, per Topic:Uyr5gphaxbpe5k4h" from mw:Module:No globals. (docs, translate)
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Line 2: Line 2:
function mt.__index (t, k)
function mt.__index (t, k)
if k ~= 'arg' then
if k ~= 'arg' then
-- perf optimization here and below: do not load Module:TNT unless there is an error
error('Tried to read nil global ' .. tostring(k), 2)
error(require('Module:TNT').format('I18n/No globals', 'err-read', tostring(k)), 2)
end
end
return nil
return nil
Line 9: Line 8:
function mt.__newindex(t, k, v)
function mt.__newindex(t, k, v)
if k ~= 'arg' then
if k ~= 'arg' then
error(require('Module:TNT').format('I18n/No globals', 'err-write', tostring(k)), 2)
error('Tried to write global ' .. tostring(k), 2)
end
end
rawset(t, k, v)
rawset(t, k, v)
end
end
setmetatable(_G, mt)
setmetatable(_G, mt)

Latest revision as of 13:02, 17 October 2022

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)