com.hazelcast.org.apache.calcite.schema.FunctionParameter Maven / Gradle / Ivy
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* 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 com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.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 com.hazelcast.org.apache.calcite.schema;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeFactory;
/**
* Parameter to a {@link Function}.
*
* NOTE: We'd have called it {@code Parameter} but the overlap with
* {@link java.lang.reflect.Parameter} was too confusing.
*/
public interface FunctionParameter {
/**
* Zero-based ordinal of this parameter within the member's parameter
* list.
*
* @return Parameter ordinal
*/
int getOrdinal();
/**
* Name of the parameter.
*
* @return Parameter name
*/
String getName();
/**
* Returns the type of this parameter.
*
* @param typeFactory Type factory to be used to create the type
*
* @return Parameter type.
*/
RelDataType getType(RelDataTypeFactory typeFactory);
/**
* Returns whether this parameter is optional.
*
* If true, the value of the parameter can be supplied using the DEFAULT
* SQL keyword, or it can be omitted from a function called using argument
* assignment, or the function can be called with fewer parameters (if all
* parameters after it are optional too).
*
*
If a parameter is optional its default value is NULL. We may in future
* allow functions to specify other default values.
*/
boolean isOptional();
}