org.neo4j.cypher.internal.logical.plans.LetSelectOrSemiApply.scala Maven / Gradle / Ivy

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/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.cypher.internal.logical.plans

import org.neo4j.cypher.internal.expressions.Expression
import org.neo4j.cypher.internal.util.attribution.IdGen

/**
 * Like LetSemiApply, but with a precondition 'expr'. If 'expr' is true, 'idName' will be set to true without
 * executing right.
 *
 * for ( leftRow <- left ) {
 *   if ( leftRow.evaluate( expr) ) {
 *     leftRow('idName') = true
 *     produce leftRow
 *   } else {
 *     right.setArgument( leftRow )
 *     leftRow('idName') = right.nonEmpty ? true : (expr.isNull ? NULL : false)
 *     produce leftRow
 *   }
 * }
 */case class LetSelectOrSemiApply(override val left: LogicalPlan,
                                override val right: LogicalPlan,
                                override val idName: String,
                                override val expression: Expression)(implicit idGen: IdGen)
  extends AbstractLetSelectOrSemiApply(left, idName)(idGen) {
  override def withLhs(newLHS: LogicalPlan)(idGen: IdGen): LogicalBinaryPlan = copy(left = newLHS)(idGen)
  override def withRhs(newRHS: LogicalPlan)(idGen: IdGen): LogicalBinaryPlan = copy(right = newRHS)(idGen)
}

/**
 * Like LetAntiSemiApply, but with a precondition 'expr'. If 'expr' is true, 'idName' will be set to true without
 * executing right.
 *
 * for ( leftRow <- left ) {
 *   if ( leftRow.evaluate( expr) ) {
 *     leftRow('idName') = true
 *     produce leftRow
 *   } else {
 *     right.setArgument( leftRow )
 *     leftRow('idName') = right.isEmpty ? true : (expr.isNull ? NULL : false)
 *     produce leftRow
 *   }
 * }
 */
case class LetSelectOrAntiSemiApply(override val left: LogicalPlan,
                                    override val right: LogicalPlan,
                                    override val idName: String,
                                    override val expression: Expression)(implicit idGen: IdGen)
  extends AbstractLetSelectOrSemiApply(left, idName)(idGen) {
  override def withLhs(newLHS: LogicalPlan)(idGen: IdGen): LogicalBinaryPlan = copy(left = newLHS)(idGen)
  override def withRhs(newRHS: LogicalPlan)(idGen: IdGen): LogicalBinaryPlan = copy(right = newRHS)(idGen)
}

sealed abstract class AbstractLetSelectOrSemiApply(left: LogicalPlan, val idName: String)(idGen: IdGen)
  extends LogicalBinaryPlan(idGen) with ApplyPlan with SingleFromRightLogicalPlan {

  def expression: Expression

  override val availableSymbols: Set[String] = left.availableSymbols + idName
}