content: /*
   * 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.asterix.dataflow.data.common;
  
  import org.apache.asterix.om.typecomputer.impl.TypeComputeUtils;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.AUnionType;
  import org.apache.asterix.om.types.BuiltinType;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.om.types.TypeHelper;
  import org.apache.hyracks.algebricks.core.algebra.expressions.IMissableTypeComputer;
  
  public class MissableTypeComputer implements IMissableTypeComputer {
  
      public static final MissableTypeComputer INSTANCE = new MissableTypeComputer();
  
      private MissableTypeComputer() {
      }
  
      @Override
      public IAType makeMissableType(Object type) {
          IAType t = (IAType) type;
          return TypeHelper.canBeMissing(t) ? t
                  : t.getTypeTag() == ATypeTag.NULL ? BuiltinType.ANY : AUnionType.createMissableType(t);
      }
  
      @Override
      public boolean canBeMissing(Object type) {
          IAType t = (IAType) type;
          return TypeHelper.canBeMissing(t);
      }
  
      @Override
      public Object makeNullableType(Object type) {
          IAType t = (IAType) type;
          return TypeHelper.canBeNull(t) ? t
                  : t.getTypeTag() == ATypeTag.MISSING ? BuiltinType.ANY : AUnionType.createNullableType(t);
      }
  
      @Override
      public boolean canBeNull(Object type) {
          IAType t = (IAType) type;
          return TypeHelper.canBeNull(t);
      }
  
      @Override
      public Object getNonOptionalType(Object type) {
          IAType t = (IAType) type;
          return TypeComputeUtils.getActualType(t);
      }
  
      @Override
      public Object getNonMissableType(Object type) {
          IAType t = (IAType) type;
          if (t.getTypeTag() == ATypeTag.UNION) {
              AUnionType ut = ((AUnionType) t);
              IAType primeType = ut.getActualType();
              return ut.isNullableType() ? AUnionType.createNullableType(primeType) : primeType;
          } else {
              return t;
          }
      }
  
      @Override
      public Object getNonNullableType(Object type) {
          IAType t = (IAType) type;
          if (t.getTypeTag() == ATypeTag.UNION) {
              AUnionType ut = ((AUnionType) t);
              IAType primeType = ut.getActualType();
              return ut.isMissableType() ? AUnionType.createMissableType(primeType) : primeType;
          } else {
              return t;
          }
      }
  }
  