code: /*
   * 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.skywalking.oap.query.promql.rt;
  
  import java.util.Map;
  import org.apache.skywalking.oap.query.promql.entity.ErrorType;
  import org.apache.skywalking.oap.query.promql.entity.LabelName;
  import org.apache.skywalking.oap.query.promql.rt.result.MatcherSetResult;
  import org.apache.skywalking.oap.query.promql.rt.result.ParseResultType;
  import org.apache.skywalking.promql.rt.grammar.PromQLParser;
  import org.apache.skywalking.promql.rt.grammar.PromQLParserBaseVisitor;
  
  public class PromQLMatchVisitor extends PromQLParserBaseVisitor<MatcherSetResult> {
  
      @Override
      public MatcherSetResult visitMetricInstant(PromQLParser.MetricInstantContext ctx) {
          String metricName = ctx.metricName().getText();
          MatcherSetResult result = new MatcherSetResult();
          result.setResultType(ParseResultType.MATCH);
          result.setMetricName(metricName);
          Map<LabelName, String> labelMap = result.getLabelMap();
          if (ctx.labelList() != null) {
              for (PromQLParser.LabelContext labelCtx : ctx.labelList().label()) {
                  String labelName = labelCtx.labelName().getText();
                  String labelValue = labelCtx.labelValue().getText();
                  String labelValueTrim = labelValue.substring(1, labelValue.length() - 1);
                  try {
                      labelMap.put(LabelName.labelOf(labelName), labelValueTrim);
                  } catch (IllegalArgumentException e) {
                      result.setErrorType(ErrorType.BAD_DATA);
                      result.setErrorInfo("Label:[" + labelName + "] is illegal.");
                      return result;
                  }
              }
          }
          return result;
      }
  }
  