Add rewriter to transform equals for id(a), a.prop to in collection predicates

community/cypher/cypher-compiler-2.1/src/main/scala/org/neo4j/cypher/internal/compiler/v2_1/ast/rewriters/rewriteEqualityToInCollection.scala

+/**
+ * Copyright (c) 2002-2014 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.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 <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.cypher.internal.compiler.v2_1.ast.rewriters
+
+import org.neo4j.cypher.internal.compiler.v2_1._
+import org.neo4j.cypher.internal.compiler.v2_1.ast._
+
+object rewriteEqualityToInCollection extends Rewriter {
+  override def apply(that: AnyRef) = bottomUp(instance).apply(that)
+
+  private val instance: Rewriter = Rewriter.lift {
+    // id(a) = value
+    case predicate@Equals(func@FunctionInvocation(_, _, IndexedSeq(idExpr)), p@ConstantExpression(idValueExpr))
+      if func.function == Some(functions.Id) =>
+
+      In(func, Collection(Seq(idValueExpr))(p.position))(predicate.position)
+    // a.prop = value
+    case predicate@Equals(prop@Property(id: Identifier, propKeyName), p@ConstantExpression(idValueExpr)) =>
+
+      In(prop, Collection(Seq(idValueExpr))(p.position))(predicate.position)
+  }
+}

community/cypher/cypher-compiler-2.1/src/test/scala/org/neo4j/cypher/internal/compiler/v2_1/ast/rewriters/RewriteEqualityToInCollectionTest.scala

+/**
+ * Copyright (c) 2002-2014 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.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 <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.cypher.internal.compiler.v2_1.ast.rewriters
+
+import org.neo4j.cypher.internal.commons.CypherFunSuite
+import org.neo4j.cypher.internal.compiler.v2_1.planner.AstRewritingTestSupport
+import org.neo4j.cypher.internal.compiler.v2_1.bottomUp
+
+class RewriteEqualityToInCollectionTest extends CypherFunSuite with AstRewritingTestSupport {
+
+  test("should transform id(a) = ConstValue to id(a) IN [ConstValue]") {
+    val original = parser.parse("MATCH (a) WHERE id(a) = 42")
+    val expected = parser.parse("MATCH (a) WHERE id(a) IN [42]")
+
+    val result = original.rewrite(rewriteEqualityToInCollection)
+
+    result should equal(expected)
+  }
+
+  test("should not transform id(a) = NonConstValue") {
+    val original = parser.parse("MATCH (a) WHERE id(a) = rand()")
+
+    val result = original.rewrite(rewriteEqualityToInCollection)
+
+    result should equal(original)
+  }
+
+  test("should transform a.prop = ConstValue to a.prop IN [ConstValue]") {
+    val original = parser.parse("MATCH (a) WHERE a.prop = 42")
+    val expected = parser.parse("MATCH (a) WHERE a.prop IN [42]")
+
+    val result = original.rewrite(rewriteEqualityToInCollection)
+
+    result should equal(expected)
+  }
+
+  test("should not transform a.prop = NonConstValue") {
+    val original = parser.parse("MATCH (a) WHERE a.prop = rand()")
+
+    val result = original.rewrite(rewriteEqualityToInCollection)
+
+    result should equal(original)
+  }
+}