# Copyright 2021 EMQ Technologies Co., Ltd. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. from abc import abstractmethod from typing import List, Any from .runtime.context import Context class Function(object): """abstract class for eKuiper function plugin""" @abstractmethod def validate(self, args: List[Any]): """callback to validate against ast args, return a string error or empty string""" pass @abstractmethod def exec(self, args: List[Any], ctx: Context) -> Any: """callback to do execution, return result""" pass @abstractmethod def is_aggregate(self): """callback to check if function is for aggregation, return bool""" pass