com.hazelcast.org.apache.calcite.sql.type.SqlReturnTypeInference 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.sql.type;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.sql.SqlOperator;
import com.hazelcast.org.apache.calcite.sql.SqlOperatorBinding;
/**
* Strategy interface to infer the type of an operator call from the type of the
* operands.
*
* This interface is an example of the
* {@link com.hazelcast.org.apache.calcite.util.Glossary#STRATEGY_PATTERN strategy pattern}.
* This makes
* sense because many operators have similar, straightforward strategies, such
* as to take the type of the first operand.
*/
public interface SqlReturnTypeInference {
//~ Methods ----------------------------------------------------------------
/**
* Infers the return type of a call to an {@link SqlOperator}.
*
* @param opBinding description of operator binding
* @return inferred type; may be null
*/
RelDataType inferReturnType(
SqlOperatorBinding opBinding);
}