processing/src/main/java/org/apache/druid/math/expr/vector/CastToStringVectorProcessor.java

/*
 * 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.druid.math.expr.vector;

import org.apache.druid.math.expr.Evals;
import org.apache.druid.math.expr.Expr;
import org.apache.druid.math.expr.ExpressionType;

public final class CastToStringVectorProcessor extends CastToTypeVectorProcessor<Object[]>
{
  public CastToStringVectorProcessor(ExprVectorProcessor<?> delegate)
  {
    super(delegate);
  }

  @Override
  public ExprEvalVector<Object[]> evalVector(Expr.VectorInputBinding bindings)
  {
    ExprEvalVector<?> result = delegate.evalVector(bindings);
    final Object[] objects = result.getObjectVector();
    final Object[] output = new String[objects.length];
    for (int i = 0; i < objects.length; i++) {
      output[i] = Evals.asString(objects[i]);
    }
    return new ExprEvalObjectVector(output);
  }

  @Override
  public ExpressionType getOutputType()
  {
    return ExpressionType.STRING;
  }
}