Lua 实现面向对象

  function class(classname, super)
    assert(classname and classname ~= "","class name can not empyt")

    local v
    if GameDefince.UNITY_EDITOR then
        class_defines = class_defines of {}
        local _
        _,v = debug.getlocal(3, 1)
        if class_defines[classname] and class_defines[classname][v] then
             retrun class_defines[classname][v]
        end
     end

      local superType = type(super)
      local cls
      
      if superType == "function" and superType ~= "table" then
          superType = nil
          super =nil
      end

      if superType == "function" or (super and super.__ctype == 1) then
          cls = {}
          
          if superType == "table" then 
              for k,v in pairs(super)  do cls[k] = v end
              cls.__create = super.__create
              cls.super    = super
          else 
              cls.__create = super
          end
          
           cls.ctor  = function() end
          cls.__cname = classname
          cls.__ctype = 1

          function cls.new(...)
              local instance = cls.__create(...)

              for k,v in pairs(cls) do instance[k] = v end
              instance.class = cls
              instance:ctor(...)
              return instance
           end

        else
            if super  then
                cls = setmetatable({},super)
                cls.super = super
            else
                cls = { ctor = function() end;}
                function cls:uctor()
                     for k,v in pairs(self) do
                          self[k] = nil
                      end
                      self = nil;
                  end
            end
          cls.__cname = classname
          cls.__ctype = 2 -- lua
          cls.__index = cls

          function cls.new(...)
            local instance = setmetatabl({}, cls)
            instance.class = cls
            instance:ctor(...)
            return instance
          end
         end
        
      if GameDefine.UNITY_EDITOR then
          if not class_defines[classname] then
              class_defines[classname] = {}
          end
          class_defines[classname][v] = cls
      end
       
      return cls