| /* |
| * 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.beam.sdk.extensions.sql.impl.cep; |
| |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rex.RexPatternFieldRef; |
| |
| /** |
| * A {@code CEPFieldRef} instance represents a node that points to a specified field in a {@code |
| * Row}. It has similar functionality as Calcite's {@code RexPatternFieldRef}. |
| */ |
| public class CEPFieldRef extends CEPOperation { |
| |
| private final String alpha; |
| private final int fieldIndex; |
| |
| CEPFieldRef(String alpha, int fieldIndex) { |
| this.alpha = alpha; |
| this.fieldIndex = fieldIndex; |
| } |
| |
| public static CEPFieldRef of(RexPatternFieldRef rexFieldRef) { |
| return new CEPFieldRef(rexFieldRef.getAlpha(), rexFieldRef.getIndex()); |
| } |
| |
| public String getAlpha() { |
| return alpha; |
| } |
| |
| public int getIndex() { |
| return fieldIndex; |
| } |
| |
| @Override |
| public String toString() { |
| return String.format("%s.$%d", alpha, fieldIndex); |
| } |
| } |