在Lua C API中克隆Lua表

shallow_copy = function(tab)
    local retval = {}
    for k,v in pairs(tab) do
        retval[k] = v
    end
    return retval
end

所以我们需要获取堆栈上的表索引和lua_State.

void shallow_copy(lua_State* L,int index) {

/*Create a new table on the stack.*/

        lua_newtable(L);

/*Now we need to iterate through the table. 
Going to steal the Lua API's example of this.*/

        lua_pushnil(L);
        while(lua_next(L,index) != 0) {
/*Need to duplicate the key,as we need to set it
(one pop) and keep it for lua_next (the next pop). Stack looks like table,k,v.*/


            lua_pushvalue(L,-2);
/*Now the stack looks like table,v,k. 
But now the key is on top. Settable expects the value to be on top. So we 
need to do a swaparooney.*/

            lua_insert(L,-2);

    /*Now we just set them. Stack looks like table,so the table is at -4*/



    lua_settable(L,-4);

/*Now the key and value were set in the table,and we popped off,so we have
table,k on the stack- which is just what lua_next wants,as it wants to find
the next key on top. So we're good.*/

        }
    }

现在我们复制的表位于堆栈的顶部.

基督,Lua API糟透了.