twalthr commented on a change in pull request #8062: [FLINK-11884][table] Implement expression resolution on top of new Expressions URL: https://github.com/apache/flink/pull/8062#discussion_r273017053
########## File path: flink-table/flink-table-planner/src/main/java/org/apache/flink/table/expressions/ExpressionResolver.java ########## @@ -0,0 +1,298 @@ +/* + * 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.flink.table.expressions; + +import org.apache.flink.annotation.PublicEvolving; +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.table.api.GroupWindow; +import org.apache.flink.table.api.OverWindow; +import org.apache.flink.table.api.SessionWithGapOnTimeWithAlias; +import org.apache.flink.table.api.SlideWithSizeAndSlideOnTimeWithAlias; +import org.apache.flink.table.api.TableException; +import org.apache.flink.table.api.TumbleWithSizeOnTimeWithAlias; +import org.apache.flink.table.api.ValidationException; +import org.apache.flink.table.expressions.lookups.FieldReferenceLookup; +import org.apache.flink.table.expressions.lookups.OperationFieldLookup; +import org.apache.flink.table.expressions.lookups.TableReferenceLookup; +import org.apache.flink.table.expressions.rules.ResolverRule; +import org.apache.flink.table.expressions.rules.ResolverRules; +import org.apache.flink.table.operations.TableOperation; +import org.apache.flink.table.plan.logical.LogicalOverWindow; +import org.apache.flink.table.plan.logical.LogicalWindow; +import org.apache.flink.table.plan.logical.SessionGroupWindow; +import org.apache.flink.table.plan.logical.SlidingGroupWindow; +import org.apache.flink.table.plan.logical.TumblingGroupWindow; +import org.apache.flink.util.Preconditions; + +import javax.annotation.Nullable; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collections; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.function.Function; +import java.util.stream.Collectors; + +import scala.Some; + +import static java.util.stream.Collectors.toList; + +/** + * Tries to resolve all unresolved expressions such as {@link UnresolvedReferenceExpression} + * or calls such as {@link BuiltInFunctionDefinitions#OVER}. + * + * <p>The default set of rules ({@link ExpressionResolverBuilder#getDefaultRules()}) will resolve following references: + * <ul> + * <li>flatten '*' to all fields of underlying inputs</li> + * <li>join over aggregates with corresponding over windows into a single resolved call</li> + * <li>resolve remaining unresolved references to fields, tables or local references</li> + * <li>replace call to {@link BuiltInFunctionDefinitions#FLATTEN}</li> + * <li>performs call arguments types validation and inserts additional casts if possible</li> + * </ul> + */ +public class ExpressionResolver { Review comment: `@Internal` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
