org.neo4j.cypher.internal.expressions.PathExpression.scala Maven / Gradle / Ivy
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/*
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [https://neo4j.com]
*
* Licensed 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.neo4j.cypher.internal.expressions
import org.neo4j.cypher.internal.util.InputPosition
sealed trait PathStep extends Expression {
def dependencies: Set[LogicalVariable]
override def isConstantForQuery: Boolean = false
}
final case class NodePathStep(node: LogicalVariable, next: PathStep)(val position: InputPosition) extends PathStep {
override val dependencies: Set[LogicalVariable] = next.dependencies + node
}
final case class SingleRelationshipPathStep(
rel: LogicalVariable,
direction: SemanticDirection,
toNode: Option[LogicalVariable],
next: PathStep
)(val position: InputPosition) extends PathStep {
override val dependencies: Set[LogicalVariable] = next.dependencies ++ toNode + rel
}
final case class MultiRelationshipPathStep(
rel: LogicalVariable,
direction: SemanticDirection,
toNode: Option[LogicalVariable],
next: PathStep
)(val position: InputPosition) extends PathStep {
override val dependencies: Set[LogicalVariable] = next.dependencies ++ toNode + rel
}
final case class RepeatPathStep(variables: Seq[NodeRelPair], toNode: LogicalVariable, next: PathStep)(
val position: InputPosition
) extends PathStep {
override def dependencies: Set[LogicalVariable] = next.dependencies ++ variables.flatMap(_.variables) ++ Set(toNode)
}
object RepeatPathStep {
def asRepeatPathStep(
variables: Seq[LogicalVariable],
toNode: LogicalVariable,
next: PathStep
)(position: InputPosition): RepeatPathStep = {
val nodeRelPairs = variables.grouped(2).toSeq.flatMap {
case Seq(node: LogicalVariable, rel: LogicalVariable) => Some(NodeRelPair(node, rel))
case _ => None
}
RepeatPathStep(nodeRelPairs, toNode, next)(position)
}
}
case class NilPathStep()(val position: InputPosition) extends PathStep {
override def dependencies = Set.empty[LogicalVariable]
}
case class PathExpression(step: PathStep)(val position: InputPosition) extends Expression {
override def isConstantForQuery: Boolean = false
}
case class NodeRelPair(node: LogicalVariable, relationship: LogicalVariable) {
def variables: Seq[LogicalVariable] = Seq(node, relationship)
}