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.runtime.evaluators.functions;
  
  import org.apache.asterix.om.functions.BuiltinFunctions;
  import org.apache.asterix.om.functions.IFunctionDescriptorFactory;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
  import org.apache.asterix.runtime.functions.FunctionTypeInferers;
  import org.apache.asterix.runtime.utils.DescriptorFactoryUtil;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
  import org.apache.hyracks.api.context.IEvaluatorContext;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  
  /**
   * <pre>
   * array_append(list, val1, val2, ...) returns a new list with all the values appended to the input list items.
   * Values can be null (i.e., one can append nulls)
   *
   * It throws an error at compile time if the number of arguments < 2
   *
   * It returns in order:
   * 1. missing, if any argument is missing.
   * 2. null, if the list arg is null or it's not a list.
   * 3. otherwise, a new list.
   *
   * </pre>
   */
  public class ArrayAppendDescriptor extends AbstractScalarFunctionDynamicDescriptor {
      private static final long serialVersionUID = 1L;
      private IAType[] argTypes;
  
      public static final IFunctionDescriptorFactory FACTORY =
              DescriptorFactoryUtil.createFactory(ArrayAppendDescriptor::new, FunctionTypeInferers.SET_ARGUMENTS_TYPE);
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.ARRAY_APPEND;
      }
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args)
              throws AlgebricksException {
          return new IScalarEvaluatorFactory() {
              private static final long serialVersionUID = 1L;
  
              @Override
              public IScalarEvaluator createScalarEvaluator(final IEvaluatorContext ctx) throws HyracksDataException {
                  return new ArrayAppendEval(args, ctx);
              }
          };
      }
  
      @Override
      public void setImmutableStates(Object... states) {
          argTypes = (IAType[]) states;
      }
  
      public class ArrayAppendEval extends AbstractArrayAddRemoveEval {
  
          ArrayAppendEval(IScalarEvaluatorFactory[] args, IEvaluatorContext ctx) throws HyracksDataException {
              super(args, ctx, 0, 1, args.length - 1, argTypes, true, true);
          }
      }
  }
  