/*
* 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;
import org.apache.cassandra.transport.ProtocolVersion;
/**
* 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(ProtocolVersion protocolVersion, List<ByteBuffer> parameters) throws InvalidRequestException;
}