--

-- nil.lua: restricts global var writes and catches undefined global var access

--

--



print "nil.lua"



do

    local mt = {};

    mt.__index    = function( t, k ) error("Attempt to access global '" .. k .. "' (nil)") end;

    mt.__newindex = function( t, k, v ) error("Attempt to write global '" .. k .. "'" ) end;



    setmetatable( _G, mt );



    rawset( _G, "global", function(expr)

        for k,v in pairs(expr) do

            rawset( _G, k, v );

        end;

    end );

end



-- Tests:

if 1 then



    -- should raise an error

    local function test_for_global_access()

        XXXXXXXXXXX = 42

    end



    --- should raise an error

    local function test_for_uninitialized_global()

        local var = XXXXXXXXXXXXXXXXXX

    end

  

    local result,message = pcall( test_for_global_access )

    assert( not result, "Test test_for_global_access FAILED!" )



    local result,message = pcall( test_for_uninitialized_global )

    assert( not result, "Test test_for_uninitialized_global failed!" )



end