AppsheetEpplus/FormulaParsing/Excel/Functions/RefAndLookup/LookupNavigator.cs

/* Copyright (C) 2011  Jan Källman
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * The GNU Lesser General Public License can be viewed at http://www.opensource.org/licenses/lgpl-license.php
 * If you unfamiliar with this license or have questions about it, here is an http://www.gnu.org/licenses/gpl-faq.html
 *
 * All code and executables are provided "as is" with no warranty either express or implied.
 * The author accepts no liability for any damage or loss of business that this product may cause.
 *
 * Code change notes:
 *
 * Author							Change						Date
 *******************************************************************************
 * Mats Alm   		                Added		                2013-12-03
 *******************************************************************************/


namespace AppsheetEpplus;

public abstract class LookupNavigator {
  protected readonly LookupDirection Direction;
  protected readonly LookupArguments Arguments;
  protected readonly ParsingContext ParsingContext;

  public LookupNavigator(
      LookupDirection direction,
      LookupArguments arguments,
      ParsingContext parsingContext) {
    Require.That(arguments).Named("arguments").IsNotNull();
    Require.That(parsingContext).Named("parsingContext").IsNotNull();
    Require
        .That(parsingContext.ExcelDataProvider)
        .Named("parsingContext.ExcelDataProvider")
        .IsNotNull();
    Direction = direction;
    Arguments = arguments;
    ParsingContext = parsingContext;
  }

  public abstract int Index { get; }

  public abstract bool MoveNext();

  public abstract object CurrentValue { get; }

  public abstract object GetLookupValue();
}