-- lua的面向对象封装
-- Author: 云风
local _class = {}

function class(super)
    local class_type = {}
    class_type.ctor = false
    class_type.super = super
    class_type.new = function(...)
        local obj = {}
        do
            local create
            create = function(c, ...)
                if c.super then create(c.super, ...) end
                if c.ctor then c.ctor(obj, ...) end
            end

            create(class_type, ...)
        end
        setmetatable(obj, {
            __index = _class[class_type]
        })
        return obj
    end
    local vtbl = {}
    _class[class_type] = vtbl

    setmetatable(class_type, {
        __newindex = function(t, k, v) vtbl[k] = v end
    })

    if super then
        setmetatable(vtbl, {
            __index = function(t, k)
                local ret = _class[super][k]
                vtbl[k] = ret
                return ret
            end
        })
    end

    return class_type
end
