snuyanzin commented on code in PR #28140: URL: https://github.com/apache/flink/pull/28140#discussion_r3217551276
########## flink-table/flink-table-common/src/main/java/org/apache/flink/table/types/inference/strategies/RegexpExtractInputTypeStrategy.java: ########## @@ -0,0 +1,117 @@ +/* + * 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.types.inference.strategies; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.functions.BuiltInFunctionDefinitions; +import org.apache.flink.table.functions.FunctionDefinition; +import org.apache.flink.table.types.DataType; +import org.apache.flink.table.types.inference.ArgumentCount; +import org.apache.flink.table.types.inference.ArgumentTypeStrategy; +import org.apache.flink.table.types.inference.CallContext; +import org.apache.flink.table.types.inference.ConstantArgumentCount; +import org.apache.flink.table.types.inference.InputTypeStrategy; +import org.apache.flink.table.types.inference.Signature; +import org.apache.flink.table.types.inference.Signature.Argument; +import org.apache.flink.table.types.logical.LogicalTypeFamily; +import org.apache.flink.table.types.logical.LogicalTypeRoot; + +import java.util.List; +import java.util.Optional; +import java.util.regex.Pattern; +import java.util.regex.PatternSyntaxException; + +import static org.apache.flink.table.types.inference.InputTypeStrategies.logical; + +/** + * Input type strategy for {@link BuiltInFunctionDefinitions#REGEXP_EXTRACT}. Validates literal + * regex patterns at planning time. + */ +@Internal +public class RegexpExtractInputTypeStrategy implements InputTypeStrategy { + + private static final int ARG_STR = 0; + private static final int ARG_REGEX = 1; + private static final int ARG_EXTRACT_INDEX = 2; + + private static final ArgumentTypeStrategy STRING_ARG = + logical(LogicalTypeFamily.CHARACTER_STRING); + private static final ArgumentTypeStrategy INT_ARG = logical(LogicalTypeRoot.INTEGER); + + @Override + public ArgumentCount getArgumentCount() { + return ConstantArgumentCount.between(2, 3); + } + + @Override + public Optional<List<DataType>> inferInputTypes( + final CallContext callContext, final boolean throwOnFailure) { + if (STRING_ARG.inferArgumentType(callContext, ARG_STR, throwOnFailure).isEmpty()) { + return Optional.empty(); + } + if (STRING_ARG.inferArgumentType(callContext, ARG_REGEX, throwOnFailure).isEmpty()) { + return Optional.empty(); + } + if (callContext.getArgumentDataTypes().size() > ARG_EXTRACT_INDEX + && INT_ARG.inferArgumentType(callContext, ARG_EXTRACT_INDEX, throwOnFailure) + .isEmpty()) { + return Optional.empty(); + } + + final Optional<List<DataType>> patternError = + validateLiteralPattern(callContext, throwOnFailure); + if (patternError.isPresent()) { + return patternError; + } + + return Optional.of(callContext.getArgumentDataTypes()); + } + + private static Optional<List<DataType>> validateLiteralPattern( + final CallContext callContext, final boolean throwOnFailure) { + if (!callContext.isArgumentLiteral(ARG_REGEX) || callContext.isArgumentNull(ARG_REGEX)) { + return Optional.empty(); + } + final Optional<String> pattern = callContext.getArgumentValue(ARG_REGEX, String.class); + if (pattern.isEmpty()) { + return Optional.empty(); + } + try { + Pattern.compile(pattern.get()); + return Optional.empty(); + } catch (PatternSyntaxException e) { + return callContext.fail( + throwOnFailure, + "Invalid regular expression for REGEXP_EXTRACT: %s", + e.getMessage()); + } Review Comment: Am right that it will not catch cases if pattern is not a constant, rather taken from another column or result of function? -- 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]
