Difference between revisions of "Module:No globals"
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function mt.__index (t, k) | function mt.__index (t, k) | ||
if k ~= 'arg' then | if k ~= 'arg' then | ||
| − | + | error('Tried to read nil global ' .. tostring(k), 2) | |
| − | error | ||
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 | + | 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 21:18, 1 October 2020
 | This module is rated as ready for general use. It has reached a mature form and is thought to be bug-free and ready for use wherever appropriate. It is ready to mention on help pages and other Wikipedia resources as an option for new users to learn. To reduce server load and bad output, it should be improved by sandbox testing rather than repeated trial-and-error editing. |
 | This module is subject to page protection. It is a highly visible module in use by a very large number of pages, or is substituted very frequently. Because vandalism or mistakes would affect many pages, and even trivial editing might cause substantial load on the servers, it is protected from editing. |
 Warning: | Do not edit. This page is maintained by a bot. All edits should be done at mediawiki.org. (translate this warning) Please help translate this page. |
Usage
Include this module at the top of your code. An error will be raised any time your code tries to read or write to a non-local (undeclared) variable.
Tests
| Module:No globals | success: 1, error: 0, skipped: 0 |
| Module:No globals/sandbox | success: 1, error: 0, skipped: 0 |
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)