fs2open.github.com/code/scripting/api/libs/hookvars.cpp

//
//

#include "hookvars.h"


namespace scripting {
namespace api {

//**********LIBRARY: Scripting Variables
ADE_LIB(l_HookVar, "HookVariables", "hv", "Hook variables repository");

//WMC: IMPORTANT
//Be very careful when modifying this library, as the Globals[] library does depend
//on the current number of items in the library. If you add _anything_, modify __len.
//Or run changes by me.

//*****LIBRARY: Scripting Variables
ADE_LIB_DERIV(l_HookVar_Globals, "Globals", nullptr, nullptr, l_HookVar);

ADE_INDEXER(l_HookVar_Globals, "number Index", "Array of current HookVariable names", "string", "Hookvariable name, or empty string if invalid index specified")
{
	int idx;
	if(!ade_get_args(L, "*i", &idx))
		return ade_set_error(L, "s", "");

	//Get lib
	lua_getglobal(L, l_HookVar.GetName());
	int lib_ldx = lua_gettop(L);
	if(!lua_isuserdata(L, lib_ldx))
	{
		lua_pop(L, 1);
		return ade_set_error(L, "s", "");
	}

	//Get metatable
	lua_getmetatable(L, lib_ldx);
	int mtb_ldx = lua_gettop(L);
	if(!lua_istable(L, mtb_ldx))
	{
		lua_pop(L, 2);
		return ade_set_error(L, "s", "");
	}

	//Get ade members table
	lua_pushstring(L, "__ademembers");
	lua_rawget(L, mtb_ldx);
	int amt_ldx = lua_gettop(L);
	if(!lua_istable(L, amt_ldx))
	{
		lua_pop(L, 3);
		return ade_set_error(L, "s", "");
	}

	//List 'em
	int count = 1;
	lua_pushnil(L);
	while(lua_next(L, amt_ldx))
	{
		//Now on stack: Key, value
		lua_pushvalue(L, -2);
		auto keyname = lua_tostring(L, -1);
		if(strcmp(keyname, "Globals") != 0)
		{
			if(count == idx)
			{
				//lib, mtb, amt, key, value, string go bye-bye
				lua_pop(L, 5);
				return ade_set_args(L, "s", keyname);
			}
			count++;
		}
		lua_pop(L, 2);	//Value, string
	}

	lua_pop(L, 3);	//lib, mtb, amt

	return ade_set_error(L, "s", "");
}

ADE_FUNC(__len, l_HookVar_Globals, NULL, "Number of HookVariables", "number", "Number of HookVariables")
{
	//Get metatable
	lua_getglobal(L, l_HookVar.GetName());
	int lib_ldx = lua_gettop(L);
	if(!lua_isuserdata(L, lib_ldx))
	{
		lua_pop(L, 1);
		return ade_set_error(L, "i", 0);
	}

	lua_getmetatable(L, lib_ldx);
	int mtb_ldx = lua_gettop(L);
	if(!lua_istable(L, mtb_ldx))
	{
		lua_pop(L, 2);
		return ade_set_error(L, "i", 0);
	}

	//Get ade members table
	lua_pushstring(L, "__ademembers");
	lua_rawget(L, mtb_ldx);
	int amt_ldx = lua_gettop(L);
	if(!lua_istable(L, amt_ldx))
	{
		lua_pop(L, 3);
		return ade_set_error(L, "i", 0);
	}

	int total_len = 0;
	lua_pushnil(L);
	while(lua_next(L, amt_ldx))
	{
		total_len++;
		lua_pop(L, 1);	//value
	}
	size_t num_sub = ade_manager::getInstance()->getEntry(l_HookVar.GetIdx()).Num_subentries;

	lua_pop(L, 3);

	//WMC - Return length, minus the 'Globals' library
	return ade_set_args(L, "i", (int)(total_len - num_sub));
}


}
}