Redis table with __index metamethod

gistfile1.lua

local fail_safe = {
	__index = function(t, command)
		error( ("No command defined for %q"):format(tostring(command)) )
	end
}
setmetatable(fail_safe, fail_safe)

-- You add commands here (internally)
local commands = {
	get = function(t, key)
		return 42
	end,
	set = function(t, key, value)
	end
}
setmetatable(commands, fail_safe)

local redis = setmetatable({}, {
	__index = commands
})

print( redis.get("x") )

-- a non existing command
redis.foo()