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potatOS/minify/strict.lua

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2021-03-31 18:58:54 +00:00
-- From http://metalua.luaforge.net/src/lib/strict.lua.html
--
-- strict.lua
-- checks uses of undeclared global variables
-- All global variables must be 'declared' through a regular assignment
-- (even assigning nil will do) in a main chunk before being used
-- anywhere or assigned to inside a function.
--
local mt = getmetatable(_G)
if mt == nil then
mt = {}
setmetatable(_G, mt)
end
__STRICT = true
mt.__declared = {}
mt.__newindex = function (t, n, v)
if __STRICT and not mt.__declared[n] then
local w = debug.getinfo(2, "S").what
if w ~= "main" and w ~= "C" then
error("assign to undeclared variable '"..n.."'", 2)
end
mt.__declared[n] = true
end
rawset(t, n, v)
end
mt.__index = function (t, n)
if not mt.__declared[n] and debug.getinfo(2, "S").what ~= "C" then
error("variable '"..n.."' is not declared", 2)
end
return rawget(t, n)
end
function global(...)
for _, v in ipairs{...} do mt.__declared[v] = true end
end