Module:No globals: Difference between revisions

From Snakeoil OS Reference
Jump to navigation Jump to search
en>Jackmcbarn
(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...')
 
en>Jackmcbarn
(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 04:46, 24 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)