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.common.annotations.MissingNullInOutFunction;
  import org.apache.asterix.om.functions.BuiltinFunctions;
  import org.apache.asterix.om.functions.IFunctionDescriptor;
  import org.apache.asterix.om.functions.IFunctionDescriptorFactory;
  import org.apache.asterix.om.functions.IFunctionTypeInferer;
  import org.apache.asterix.om.typecomputer.impl.TypeComputeUtils;
  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.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;
  
  /**
   * Implements 'lax' cast. It differs from the regular cast as follows:
   * <ul>
   * <li>Numeric type demotion does not fail if the input value is not within bounds for the target type.
   * Instead it returns min/max value of the target type.
   * </li>
   * <li>
   * If there's an error during casting then 'MISSING' is returned.
   * Note that errors from argument evaluation are still propagated.
   * </li>
   * </ul>
   */
  
  @MissingNullInOutFunction
  public class CastTypeLaxDescriptor extends AbstractScalarFunctionDynamicDescriptor {
  
      public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
          @Override
          public IFunctionDescriptor createFunctionDescriptor() {
              return new CastTypeLaxDescriptor();
          }
  
          @Override
          public IFunctionTypeInferer createFunctionTypeInferer() {
              return new FunctionTypeInferers.CastTypeInferer();
          }
      };
  
      private static final long serialVersionUID = 1L;
      private IAType reqType;
      private IAType inputType;
  
      private CastTypeLaxDescriptor() {
      }
  
      @Override
      public void setImmutableStates(Object... states) {
          reqType = (IAType) states[0];
          inputType = (IAType) states[1];
          // If reqType or inputType is null, or they are the same, it indicates there is a bug in the compiler.
          if (reqType == null || inputType == null || reqType.equals(inputType)) {
              throw new IllegalStateException(
                      "Invalid types for casting, required type " + reqType + ", input type " + inputType);
          }
          // NULLs and MISSINGs are handled by the generated code, therefore we only need to handle actual types here.
          this.reqType = TypeComputeUtils.getActualType(reqType);
          this.inputType = TypeComputeUtils.getActualType(inputType);
      }
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.CAST_TYPE_LAX;
      }
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args) {
          final IScalarEvaluatorFactory recordEvalFactory = args[0];
  
          return new IScalarEvaluatorFactory() {
              private static final long serialVersionUID = 1L;
  
              @Override
              public IScalarEvaluator createScalarEvaluator(IEvaluatorContext ctx) throws HyracksDataException {
                  IScalarEvaluator argEval = recordEvalFactory.createScalarEvaluator(ctx);
                  return new CastTypeLaxEvaluator(reqType, inputType, argEval, sourceLoc);
              }
          };
      }
  }
  