// lua table 的非循环依赖遍历，这代码很简单，但有几点是需要注意的：
// 1 lua_isstring()、lua_isnumber()之类的函数的判断依据是可否转型；
// 2 lua_tostring()、lua_tonumber()之类的函数是有副作用的；
// 3 lua_next() 需要用到的key是类型敏感的；
// 4 print_table()不可遍历带循环引用的复杂表；
static?void?print_table(lua_State* L) {
????int?l = lua_gettop(L);????printf("[table] %d\n", l);????lua_pushnil(L);????while?(lua_next(L, -2)) {
????????switch?(lua_type(L, -1)) {
????????case?LUA_TNIL:
????????????assert(0);
????????????printf("[nil] nil\n");
????????????break;
????????case?LUA_TBOOLEAN:
????????????printf("[boolean] %s\n", lua_toboolean(L, -1) ? "true"?: "false");
????????????break;
????????case?LUA_TLIGHTUSERDATA:
????????????printf("[lightuserdata] 0x%x\n", lua_topointer(L, -1));
????????????break;
????????case?LUA_TNUMBER:
????????????printf("[number] %f\n", lua_tonumber(L, -1));
????????????break;
????????case?LUA_TSTRING:
????????????printf("[string] %s\n", lua_tostring(L, -1));
????????????break;
????????case?LUA_TTABLE:
????????????print_table(L);
????????????break;
????????case?LUA_TFUNCTION:
????????????printf("[function] 0x%x\n", lua_topointer(L, -1));
????????????break;
????????case?LUA_TUSERDATA:
????????????printf("userdata] 0x%x\n", lua_topointer(L, -1));
????????????break;
????????case?LUA_TTHREAD:
????????????printf("[thread] 0x%x\n", lua_topointer(L, -1));
????????????break;
????????default:
????????????assert(0);
????????}
????????lua_pop(L, 1);
????}????assert(lua_gettop(L) == l);
}int?main(int?argc, char* argv[]) {
????lua_State* L = lua_open();
????if?(L) {
????????int?err = luaL_dofile(L, "test.lua");
????????if?(err) {
????????????printf("[error] %s\n", lua_tostring(L, -1));
????????} else?{
????????????// elements 是 test.lua 里面的一全局表
????????????lua_getglobal(L, "elements");
????????????if?(lua_istable(L)) {
????????????????print_table(L);
????????????}
????????????lua_pop(L, 1);
????????}
????????lua_close(L);
????}
????return?0;
}
