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.om.typecomputer.impl;
  
  import java.util.List;
  
  import org.apache.asterix.common.exceptions.CompilationException;
  import org.apache.asterix.common.exceptions.ErrorCode;
  import org.apache.asterix.om.typecomputer.base.IResultTypeComputer;
  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.commons.lang3.mutable.Mutable;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression;
  import org.apache.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression;
  import org.apache.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
  import org.apache.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;
  
  public class DoubleIfTypeComputer implements IResultTypeComputer {
  
      public static final DoubleIfTypeComputer INSTANCE = new DoubleIfTypeComputer();
  
      @Override
      public IAType computeType(ILogicalExpression expression, IVariableTypeEnvironment env,
              IMetadataProvider<?, ?> metadataProvider) throws AlgebricksException {
          AbstractFunctionCallExpression fce = (AbstractFunctionCallExpression) expression;
          List<Mutable<ILogicalExpression>> arguments = fce.getArguments();
          if (arguments.size() != 2) {
              String functionName = fce.getFunctionIdentifier().getName();
              throw new CompilationException(ErrorCode.COMPILATION_INVALID_NUM_OF_ARGS, fce.getSourceLocation(),
                      functionName);
          }
          Mutable<ILogicalExpression> firstArg = arguments.get(0);
          IAType firstArgType = (IAType) env.getType(firstArg.getValue());
          if (firstArgType.getTypeTag() == ATypeTag.DOUBLE) {
              return firstArgType;
          } else if (firstArgType.getTypeTag() == ATypeTag.UNION) {
              AUnionType unionType = (AUnionType) firstArgType;
              IAType actualType = unionType.getActualType();
              if (actualType.getTypeTag() == ATypeTag.DOUBLE && unionType.isUnknownableType()) {
                  return unionType;
              }
          }
  
          return BuiltinType.ANY;
      }
  }
  