Golang State.GetField方法代码示例

func outputNumbersToStrings(L *lua.State) {
	L.GetGlobal("output")

	if !L.IsTable(-1) {
		L.NewTable()
		L.SetGlobal("output")
	}

	L.GetField(-1, "tags")
	if L.IsTable(-1) {
		// First key.
		L.PushNil()
		for L.Next(-2) != 0 {
			// Use 'key' at index -2 and 'value' at index -1.
			if L.IsString(-2) && L.IsString(-1) {
				// Convert numbers to strings.
				L.ToString(-1)
				L.SetField(-3, L.ToString(-2))
			} else {
				// Remove 'value' and keep 'key' for next iteration.
				L.Pop(1)
			}
		}
	}
	L.Pop(1)

	L.Pop(1)
}

// look up a Lua value by its full name. If idx is 0, then this name
// is assumed to start in the global table, e.g. "string.gsub".
// With non-zero idx, can be used to look up subfields of a table
func Lookup(L *lua.State, path string, idx int) {
	parts := strings.Split(path, ".")
	if idx != 0 {
		L.PushValue(idx)
	} else {
		L.GetGlobal("_G")
	}
	for _, field := range parts {
		L.GetField(-1, field)
		L.Remove(-2) // remove table
	}
}

func isValueProxy(L *lua.State, idx int) bool {
	res := false
	if L.IsUserdata(idx) {
		L.GetMetaTable(idx)
		if !L.IsNil(-1) {
			L.GetField(-1, "luago.value")
			res = !L.IsNil(-1)
			L.Pop(1)
		}
		L.Pop(1)
	}
	return res
}

func pushValue(state *lua.State, value interface{}) error {
	switch v := value.(type) {
	default:
		return fmt.Errorf("An item of unknown type was included in the environment or arguments of a Lua call (skipping it): %v",
			value)
	case nil:
		log.Println("Pushing nil onto lua stack")
		state.PushNil()
	case string:
		log.Println("Pushing string onto lua stack")
		state.PushString(v)
	case int:
		log.Println("Pushing int onto lua stack")
		state.PushInteger(int64(v))
	case int64:
		log.Println("Pushing int64 onto lua stack")
		state.PushInteger(v)
	case float64:
		log.Println("Pushing float64 onto lua stack")
		state.PushNumber(v)
	case bool:
		log.Println("Pushing bool onto lua stack")
		state.PushBoolean(v)

	case map[string]interface{}:
		log.Println("Pushing map[string]interface{} onto lua stack")
		state.CreateTable(0, len(v))
		for name, value := range v {
			err := pushValue(state, value)
			if err != nil {
				// error means nothing was added to stack. So pop our new table so *we* leave nothing added to the stack.
				state.Pop(1)
				return err
			}
			state.SetField(-2, name)
		}
		// then leave the table on the stack

	case ThingType:
		// These are singleton sentinel values, so load them from Lua-land.
		state.GetGlobal("world")
		state.GetField(-1, strings.Title(v.String()))
		state.Remove(-2)

	case *Thing:
		log.Println("Pushing *Thing onto lua stack")
		return pushValue(state, v.Id)
	case ThingId:
		log.Println("Pushing ThingId onto lua stack")
		// We're pushing a ThingId, so make a new userdata for it, with the Thing metatable.
		userdata := state.NewUserdata(uintptr(unsafe.Sizeof(int64(0))))
		thingPtr := (*int64)(userdata)
		*thingPtr = int64(v)
		if !state.IsUserdata(-1) {
			log.Println("!!! HOGAD JUST PUSHED NEW USERDATA BUT IT ISN'T OMG !!!")
		}
		log.Println("Pushed ThingId", *thingPtr, "onto lua stack")

		// Now make it act like a Thing.
		state.LGetMetaTable(ThingMetaTableName) // ( udata -- udata mtbl )
		state.SetMetaTable(-2)                  // ( udata mtbl -- udata )

		// Let's just check that it's that, for sures.
		if !state.IsUserdata(-1) {
			log.Println("!!! WOOP WOOP DID NOT SET METATABLE RIGHT :( !!!")
		}
	}
	return nil
}

// 'exist' is optional.
func run(L *lua.State, registryIndex string, code string, input *inputInfo, output *outputInfo, exist *inputInfo) error {
	// Restore the sandbox.
	err := L.DoString(luaRestoreSandbox)
	if err != nil {
		log.Fatal("Cannot load function to restore sandbox", err)
	}
	L.PushString(registryWhitelist)
	L.GetTable(lua.LUA_REGISTRYINDEX)
	err = L.Call(1, 0)
	if err != nil {
		log.Fatal("Failed to restore sandbox", err)
	}

	goToLua(L, "input", *input)
	goToLua(L, "output", *output)

	if exist != nil {
		goToLua(L, "existinfo", *exist)
	}

	// Shortcut (mostly for prescript and postscript).
	L.GetGlobal("input")
	L.GetField(-1, "tags")
	L.SetGlobal("i")
	L.Pop(1)
	L.GetGlobal("output")
	L.GetField(-1, "tags")
	L.SetGlobal("o")
	L.Pop(1)

	// Call the compiled script.
	L.PushString(registryIndex)
	L.GetTable(lua.LUA_REGISTRYINDEX)
	L.PushString(code)
	if L.IsTable(-2) {
		L.GetTable(-2)
		if L.IsFunction(-1) {
			err := L.Call(0, 0)
			if err != nil {
				L.SetTop(0)
				return fmt.Errorf("%s", err)
			}
		} else {
			L.Pop(1)
		}
	} else {
		L.Pop(1)
	}
	L.Pop(1)

	// Allow tags to be numbers for convenience.
	outputNumbersToStrings(L)

	L.GetGlobal("output")
	r := luar.LuaToGo(L, reflect.TypeOf(*output), -1)
	L.Pop(1)

	*output = r.(outputInfo)

	return nil
}