org.neo4j.cypher.internal.rewriting.rewriters.expandCallWhere.scala Maven / Gradle / Ivy

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Tree rewriting support, and AST rewriters for the Cypher query language

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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.rewriting.rewriters

import org.neo4j.cypher.internal.ast.ProcedureResult
import org.neo4j.cypher.internal.ast.ReturnItems
import org.neo4j.cypher.internal.ast.SingleQuery
import org.neo4j.cypher.internal.ast.UnresolvedCall
import org.neo4j.cypher.internal.ast.With
import org.neo4j.cypher.internal.rewriting.conditions.OptionalCallProcedureWrapped
import org.neo4j.cypher.internal.rewriting.conditions.SemanticInfoAvailable
import org.neo4j.cypher.internal.rewriting.rewriters.factories.PreparatoryRewritingRewriterFactory
import org.neo4j.cypher.internal.util.CypherExceptionFactory
import org.neo4j.cypher.internal.util.Rewriter
import org.neo4j.cypher.internal.util.StepSequencer
import org.neo4j.cypher.internal.util.StepSequencer.DefaultPostCondition
import org.neo4j.cypher.internal.util.StepSequencer.Step
import org.neo4j.cypher.internal.util.bottomUp

// Rewrites CALL proc WHERE  ==> CALL proc WITH * WHERE 
case object expandCallWhere extends Step with DefaultPostCondition with PreparatoryRewritingRewriterFactory {

  override def preConditions: Set[StepSequencer.Condition] = Set(OptionalCallProcedureWrapped)

  override def invalidatedConditions: Set[StepSequencer.Condition] = SemanticInfoAvailable

  val instance: Rewriter = bottomUp(Rewriter.lift {
    case query @ SingleQuery(clauses) =>
      val newClauses = clauses.flatMap {
        case unresolved @ UnresolvedCall(_, _, _, Some(result @ ProcedureResult(_, optWhere @ Some(where))), _, _) =>
          val newResult = result.copy(where = None)(result.position)
          val newUnresolved = unresolved.copy(declaredResult = Some(newResult))(unresolved.position)
          val newItems = ReturnItems(includeExisting = true, Seq.empty)(where.position)
          val newWith = With(distinct = false, newItems, None, None, None, optWhere)(where.position)
          Seq(newUnresolved, newWith)

        case clause =>
          Some(clause)
      }
      query.copy(clauses = newClauses)(query.position)
  })

  override def getRewriter(cypherExceptionFactory: CypherExceptionFactory): Rewriter = instance
}