| /* |
| * 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.wayang.api.util |
| |
| import org.apache.wayang.core.types.DataSetType |
| |
| /** |
| * This class waits for a [[org.apache.wayang.core.types.DataSetType]] to be set and verifies that there are no |
| * two different sets. |
| */ |
| class TypeTrap { |
| |
| /** |
| * Stores the [[DataSetType]]. |
| */ |
| private var _dataSetType: DataSetType[_] = _ |
| |
| /** |
| * Set the [[DataSetType]] for this instance. |
| * |
| * @throws IllegalArgumentException if a different [[DataSetType]] has been set before |
| * @param dst the [[DataSetType]] |
| */ |
| def dataSetType_=(dst: DataSetType[_]): Unit = { |
| _dataSetType match { |
| case null => _dataSetType = dst |
| case `dst` => |
| case other => throw new IllegalArgumentException(s"Conflicting types ${_dataSetType} and ${dst}.") |
| } |
| } |
| |
| /** |
| * Return the previously set [[DataSetType]]. |
| * |
| * @return the previously set [[DataSetType]] or, if none has been set, [[DataSetType.none()]] |
| */ |
| def dataSetType = _dataSetType match { |
| case null => DataSetType.none() |
| case other => other |
| } |
| |
| /** |
| * Return the [[Class]] of the previously set [[DataSetType]]. |
| * |
| * @return the [[Class]] of the previously set [[DataSetType]] or, if none has been set, that of [[DataSetType.none()]] |
| */ |
| def typeClass = dataSetType.getDataUnitType.toBasicDataUnitType.getTypeClass |
| } |