| /* |
| * 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 org.apache.vxquery.compiler.rewriter.rules; |
| |
| import org.apache.vxquery.functions.BuiltinOperators; |
| import org.apache.vxquery.runtime.functions.type.SequenceTypeMatcher; |
| import org.apache.vxquery.types.SequenceType; |
| |
| import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier; |
| |
| /** |
| * The rule searches for where the xquery treat function is used. When the |
| * expression's return type matches the treat expression type, the treat is |
| * removed. |
| * |
| * <pre> |
| * Before |
| * |
| * plan__parent |
| * %OPERATOR( $v1 : treat( \@input_expression, \@type_expression ) ) |
| * plan__child |
| * |
| * Where treat \@type_expression is the same as the return type of \@input_expression. |
| * |
| * After |
| * |
| * plan__parent |
| * %OPERATOR( $v1 : \@input_expression ) |
| * plan__child |
| * </pre> |
| * |
| * @author prestonc |
| */ |
| |
| public class RemoveRedundantTreatExpressionsRule extends AbstractRemoveRedundantTypeExpressionsRule { |
| final SequenceTypeMatcher stm = new SequenceTypeMatcher(); |
| |
| protected FunctionIdentifier getSearchFunction() { |
| return BuiltinOperators.TREAT.getFunctionIdentifier(); |
| } |
| |
| @Override |
| public boolean matchesAllInstancesOf(SequenceType sTypeArg, SequenceType sTypeOutput) { |
| if (sTypeArg != null) { |
| stm.setSequenceType(sTypeArg); |
| if (sTypeOutput != null && stm.matchesAllInstances(sTypeOutput)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| } |