EPPlus/FormulaParsing/Excel/Functions/CollectionFlattener.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
 *******************************************************************************/

using System;
using System.Collections.Generic;

namespace OfficeOpenXml.FormulaParsing.Excel.Functions;

public abstract class CollectionFlattener<T> {
  public virtual IEnumerable<T> FuncArgsToFlatEnumerable(
      IEnumerable<FunctionArgument> arguments,
      Action<FunctionArgument, IList<T>> convertFunc) {
    var argList = new List<T>();
    FuncArgsToFlatEnumerable(arguments, argList, convertFunc);
    return argList;
  }

  private void FuncArgsToFlatEnumerable(
      IEnumerable<FunctionArgument> arguments,
      List<T> argList,
      Action<FunctionArgument, IList<T>> convertFunc) {
    foreach (var arg in arguments) {
      if (arg.Value is IEnumerable<FunctionArgument> value) {
        FuncArgsToFlatEnumerable(value, argList, convertFunc);
      } else {
        convertFunc(arg, argList);
      }
    }
  }
}