lua stdlib

src/stratagus/lua/classes.lua

@@ -0,0 +1,52 @@
+local classes = {
+   _NAME = "classes",
+   _VERSION = "0.01",
+   _COPYRIGHT = "Stratagus Developers",
+   _DESCRIPTION = "Class-system for Stratagus games' lua code",
+}
+
+classes.class = function(base, init)
+   local c = {}    -- a new class instance
+   if not init and type(base) == 'function' then
+      init = base
+      base = nil
+   elseif type(base) == 'table' then
+    -- our new class is a shallow copy of the base class!
+      for i,v in pairs(base) do
+         c[i] = v
+      end
+      c._base = base
+   end
+   -- the class will be the metatable for all its objects,
+   -- and they will look up their methods in it.
+   c.__index = c
+
+   -- expose a constructor which can be called by <classname>(<args>)
+   local mt = {}
+   mt.__call = function(class_tbl, ...)
+   local obj = {}
+   setmetatable(obj,c)
+   if init then
+      init(obj,...)
+   else 
+      -- make sure that any stuff from the base class is initialized!
+      if base and base.init then
+      base.init(obj, ...)
+      end
+   end
+   return obj
+   end
+   c.init = init
+   c.is_a = function(self, klass)
+      local m = getmetatable(self)
+      while m do 
+         if m == klass then return true end
+         m = m._base
+      end
+      return false
+   end
+   setmetatable(c, mt)
+   return c
+end
+
+return classes