Allow named assemblages

src/assemblages.lua

@@ -0,0 +1,29 @@
+-- Assemblages
+
+local PATH = (...):gsub('%.[^%.]+$', '')
+
+local Type = require(PATH..".type")
+
+local Assemblages = {}
+
+function Assemblages.register(name, assemblage)
+    if (type(name) ~= "string") then
+        error("bad argument #1 to 'Assemblages.register' (string expected, got "..type(name)..")", 3)
+    end
+
+    if (not Type.isAssemblage(assemblage)) then
+        error("bad argument #2 to 'Assemblages.register' (assemblage expected, got "..type(world)..")", 3)
+    end
+
+    if (rawget(Assemblages, name)) then
+        error("bad argument #2 to 'Assemblages.register' (Assemblage with name '"..name.."' is already registerd)", 3)
+    end
+
+    Assemblages[name] = assemblage
+end
+
+return setmetatable(Assemblages, {
+    __index = function(_, name)
+        error("Attempt to index assemblage '"..tostring(name).."' that does not exist / was not registered", 2)
+    end
+})