Difference between revisions of "Module:No globals"

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(Created page with 'local mt = getmetatable(_G) or {} local oldIndex = mt.__index or function() return nil end mt.__index = function(t, k) if k ~= 'name' and k ~= 'arg' then erro...')
 
(don't bother saving old __index or __newindex)
Line 1: Line 1:
 
local mt = getmetatable(_G) or {}
 
local mt = getmetatable(_G) or {}
local oldIndex = mt.__index or function() return nil end
+
function mt.__index (t, k)
mt.__index = function(t, k)
 
 
if k ~= 'name' and k ~= 'arg' then
 
if k ~= 'name' and k ~= 'arg' then
 
error('Tried to read nil global ' .. tostring(k), 2)
 
error('Tried to read nil global ' .. tostring(k), 2)
 
end
 
end
return oldIndex(t, k)
+
return nil
 
end
 
end
local oldNewindex = mt.__newindex or rawset
 
 
function mt.__newindex(t, k, v)
 
function mt.__newindex(t, k, v)
 
if k ~= 'name' and k ~= 'arg' then
 
if k ~= 'name' and k ~= 'arg' then
 
error('Tried to write global ' .. tostring(k), 2)
 
error('Tried to write global ' .. tostring(k), 2)
 
end
 
end
oldNewindex(t, k, v)
+
rawset(t, k, v)
 
end
 
end
 
setmetatable(_G, mt)
 
setmetatable(_G, mt)

Revision as of 20:46, 23 April 2014

Documentation for this module may be created at Module:No globals/doc

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