Lua的5.2 LUA_GLOBALSINDEX替代 [英] Lua 5.2 LUA_GLOBALSINDEX Alternative

问题描述

我有嵌入Lua和实现了延迟功能查找形式的节目。

I have a program that embeds Lua and implements a form of lazy function lookup.

它在Lua 5.1，工作方式，每当一个符号是不确定的相互preTER会召唤一个全局函数钩子那么这将解决符号。

The way it worked in Lua 5.1, whenever a symbol was undefined the interpreter would call a global function hook that would then resolve the symbol.

这是实现这个懒功能查找C $ C $的c一小部分：

This is a small portion of C code that implemented this lazy function lookup:

int function_hook(lua_State *pLuaState)
{
  // do the function lookup here
  ....
  return 1;
}

......

//-- create table containing the hook details
lua_newtable(pLuaState);
lua_pushstring(pLuaState, "__index");
lua_pushcfunction(pLuaState, function_hook);
lua_settable(pLuaState, -3);

//-- set global index callback hook
lua_setmetatable(pLuaState, LUA_GLOBALSINDEX);

我现在正在试图将此code移动到Lua 5.2和所遇到的问题。

I'm now trying to move this code to Lua 5.2 and have run into a problem.

在Lua的5.2 LUA_GLOBALSINDEX值不再定义，因此这条线code不再编译。

In Lua 5.2 the LUA_GLOBALSINDEX value is no longer defined so this line of code no longer compiles.

//-- set global call back hook
lua_setmetatable(pLuaState, LUA_GLOBALSINDEX);

有一个​​参考这种变化给LUA_GLOBALSINDEX但遗憾的是它并没有帮助。

There is a reference to this change to LUA_GLOBALSINDEX but unfortunately it has not helped.

什么是重新写code的这一行有间preTER通话只要找到一个未解决的符号function_hook的最佳方式？

What would be the best way to re-write this one line of code to have the interpreter call the function_hook whenever it finds an unresolved symbol?

推荐答案

环境现在存储在该注册表一个特殊的指数。尝试：

The global environment is now stored at a special index in the registry. Try:

//-- get global environment table from registry
lua_rawgeti(pLuaState, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS);

//-- create table containing the hook details
lua_newtable(pLuaState);
lua_pushstring(pLuaState, "__index");
lua_pushcfunction(pLuaState, function_hook);
lua_settable(pLuaState, -3);

//-- set global index callback hook
lua_setmetatable(pLuaState, -2);

//-- remove the global environment table from the stack
lua_pop(pLuaState, 1);

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