com.hazelcast.org.apache.calcite.rex.RexCorrelVariable Maven / Gradle / Ivy
/*
* 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 com.hazelcast.org.apache.calcite.rex;
import com.hazelcast.org.apache.calcite.rel.core.CorrelationId;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.sql.SqlKind;
import java.util.Objects;
/**
* Reference to the current row of a correlating relational expression.
*
* Correlating variables are introduced when performing nested loop joins.
* Each row is received from one side of the join, a correlating variable is
* assigned a value, and the other side of the join is restarted.
*/
public class RexCorrelVariable extends RexVariable {
public final CorrelationId id;
//~ Constructors -----------------------------------------------------------
RexCorrelVariable(
CorrelationId id,
RelDataType type) {
super(id.getName(), type);
this.id = Objects.requireNonNull(id);
}
//~ Methods ----------------------------------------------------------------
public R accept(RexVisitor visitor) {
return visitor.visitCorrelVariable(this);
}
public R accept(RexBiVisitor visitor, P arg) {
return visitor.visitCorrelVariable(this, arg);
}
@Override public SqlKind getKind() {
return SqlKind.CORREL_VARIABLE;
}
@Override public boolean equals(Object obj) {
return this == obj
|| obj instanceof RexCorrelVariable
&& digest.equals(((RexCorrelVariable) obj).digest)
&& type.equals(((RexCorrelVariable) obj).type)
&& id.equals(((RexCorrelVariable) obj).id);
}
@Override public int hashCode() {
return Objects.hash(digest, type, id);
}
}