| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| package org.apache.cassandra.cql3.functions; |
| |
| import java.nio.ByteBuffer; |
| import java.util.List; |
| |
| import org.apache.cassandra.exceptions.InvalidRequestException; |
| |
| /** |
| * Determines a single output value based on a single input value. |
| */ |
| public interface ScalarFunction extends Function |
| { |
| public boolean isCalledOnNullInput(); |
| |
| /** |
| * Applies this function to the specified parameter. |
| * |
| * @param protocolVersion protocol version used for parameters and return value |
| * @param parameters the input parameters |
| * @return the result of applying this function to the parameter |
| * @throws InvalidRequestException if this function cannot not be applied to the parameter |
| */ |
| public ByteBuffer execute(int protocolVersion, List<ByteBuffer> parameters) throws InvalidRequestException; |
| } |