raminqaf commented on code in PR #29073: URL: https://github.com/apache/flink/pull/29073#discussion_r3922743741
########## flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/functions/casting/VariantToArrayCastRule.java: ########## @@ -0,0 +1,138 @@ +/* + * 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.planner.functions.casting; + +import org.apache.flink.table.data.ArrayData; +import org.apache.flink.table.data.GenericArrayData; +import org.apache.flink.table.planner.codegen.CodeGenUtils; +import org.apache.flink.table.runtime.functions.VariantCastUtils; +import org.apache.flink.table.types.logical.ArrayType; +import org.apache.flink.table.types.logical.LogicalType; +import org.apache.flink.table.types.logical.LogicalTypeRoot; +import org.apache.flink.types.variant.Variant; + +import static org.apache.flink.table.planner.codegen.CodeGenUtils.newName; +import static org.apache.flink.table.planner.functions.casting.CastRuleUtils.constructorCall; +import static org.apache.flink.table.planner.functions.casting.CastRuleUtils.methodCall; +import static org.apache.flink.table.planner.functions.casting.CastRuleUtils.newArray; +import static org.apache.flink.table.planner.functions.casting.CastRuleUtils.staticCall; +import static org.apache.flink.table.planner.functions.casting.CastRuleUtils.strLiteral; + +/** + * {@link LogicalTypeRoot#VARIANT} to {@link LogicalTypeRoot#ARRAY} cast rule. + * + * <p>The variant must be an array, otherwise the cast fails. Each element is itself a variant and + * casts to the target element type by the full {@code VARIANT}-to-element rule, recursively. An + * element that stores a JSON {@code null} maps to SQL {@code NULL} when the element type is + * nullable and fails the cast when it is {@code NOT NULL}. + */ +class VariantToArrayCastRule extends AbstractVariantToConstructedCastRule<ArrayData> { + + static final VariantToArrayCastRule INSTANCE = new VariantToArrayCastRule(); + + private VariantToArrayCastRule() { + super( + CastRulePredicate.builder() + .predicate( + (input, target) -> + input.is(LogicalTypeRoot.VARIANT) + && target.is(LogicalTypeRoot.ARRAY) + && CastRuleProvider.resolve( + input, + ((ArrayType) target) + .getElementType()) + != null) + .build()); + } + Review Comment: Added an example code for `ARRAY<INT>` -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
