rename folder src to concord

concord/worlds.lua

@@ -0,0 +1,33 @@
+--- Worlds
+-- Container for registered Worlds
+
+local PATH = (...):gsub('%.[^%.]+$', '')
+
+local Type = require(PATH..".type")
+
+local Worlds = {}
+
+--- Registers a World.
+-- @param name Name to register under
+-- @param world World to register
+function Worlds.register(name, world)
+    if (type(name) ~= "string") then
+        error("bad argument #1 to 'Worlds.register' (string expected, got "..type(name)..")", 3)
+    end
+
+    if (not Type.isWorld(world)) then
+        error("bad argument #2 to 'Worlds.register' (world expected, got "..type(world)..")", 3)
+    end
+
+    if (rawget(Worlds, name)) then
+        error("bad argument #2 to 'Worlds.register' (World with name '"..name.."' is already registerd)", 3)
+    end
+
+    Worlds[name] = world
+end
+
+return setmetatable(Worlds, {
+    __index = function(_, name)
+        error("Attempt to index world '"..tostring(name).."' that does not exist / was not registered", 2)
+    end
+})