卢阿 + SWIG 猴子修补
我使用 SWIG 将一组类绑定到 lua。我知道 C++ 本身不支持猴子修补，而且我并没有尝试修改我的 C++ 对象，只是修改它们的 lua 表示。如果我想开始对 SWIG 导出的 lua 表和对象进行猴子修补，这样我就可以修改 lua 端提供的 API，那么问题就来了。
例如以下 lua 代码：
game.GetEnemies1 = game.GetEnemies2
无法按预期工作。该行之后的行为仍然与原始 GetEnemies1 而不是 GetEnemies2 一致。
我该如何解决这个问题？
I have used SWIG to bind a set of classes to lua. I know C++ itself doesn't support monkey patching, and I'm not trying to modify my C++ objects, merely their lua representations. The problem comes if I want to start monkey patching the lua tables and objects exported by SWIG, so that I can modify the API presented on the lua side.
e.g. the following lua code:
game.GetEnemies1 = game.GetEnemies2
does not work as expected. The behaviour after that line is still consistent with the original GetEnemies1 not GetEnemies2.
how do I combat this problem?
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我通过添加和替换现有方法成功对 lua 用户数据进行了猴子修补。它涉及修改他们的元表。
这是我必须做的示例向现有的用户数据对象添加几个方法。
正如您所看到的，我必须修改其元表，而不是修改对象本身。
仅当您的用户数据对象设置为使其元表“指向自身”时，此解决方案才有效：
mt.__index = mt。问候！
I've successfully monkeypatched lua userdata by adding and replacing existing methods. It involved modifying their metatables.
Here's a sample of what I had to do in order to add a couple methods to an existing userdata object.
As you can see, instead of modifying the object iself, I had to modify its metatable.
This solution will only work if your userdata objects are set up so their metatables "point to themselves":
mt.__index = mt.Regards!
Swig 从 C++ 函数生成 lua 包装器，它不会将 lua 函数注入到 C++ 中。如果 GetEnemies1 是一个 C++ 函数，从其他 C++ 函数调用，猴子修补将不起作用。
您必须重写 C++ 代码，以便执行 GetEnemies1 的代码查找某种可以用 swig 包装的回调。
Swig generates lua wrappers from c++ functions, it does not inject lua functions into c++. If GetEnemies1 is a c++ function, called from other c++ functions, monkey patching wont work.
You will have to rewrite your c++ code so that the code which executes GetEnemies1 looks for some sort of callback which you can wrap with swig.