Tokenizer.cs :  » Network-Clients » DICOM » org » dicomcs » util » C# / CSharp Open Source

#region Copyright
// 
// This library is based on dcm4che see http://www.sourceforge.net/projects/dcm4che
// Copyright (c) 2002 by TIANI MEDGRAPH AG. All rights reserved.
//
// Modifications Copyright (C) 2002,2008 Fang Yang. All rights reserved.
// 
// This file is part of dicomcs, see http://www.sourceforge.net/projects/dicom-cs
//
// 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 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.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// Fang Yang (yangfang@email.com)
//
#endregion

namespace org.dicomcs.util{
  using System;

  public class Tokenizer
  {
    private System.Collections.ArrayList elements;
    private string source;
    private string delimiters = ",;\\ \t\n\r";    

    public Tokenizer(string source)
    {      
      this.elements = new System.Collections.ArrayList();
      this.source = source;
      this.ReTokenize();
    }

    public Tokenizer(string source, string delimiters)
    {
      this.elements = new System.Collections.ArrayList();
      this.delimiters = delimiters;
      this.source = source;
      this.ReTokenize();
    }

    public int Count
    {
      get
      {
        return (this.elements.Count);
      }
    }

    public bool HasMoreTokens()
    {
      return (this.elements.Count > 0);      
    }

    public string NextToken()
    {      
      string result;
      if ((source == "")
            ||  (this.elements.Count == 0)) throw new System.Exception();
      else
      {
        result = (string) this.elements[0];
        this.elements.RemoveAt(0);        
        return result;          
      }      
    }

    public string NextToken(string delimiters)
    {
      this.delimiters = delimiters;
      return NextToken();
    }

    public void ReTokenize()
    {
      int prev_index = 0;

      for (int index=0;index < this.source.Length;index++)
      {
        if (this.delimiters.IndexOf(this.source[index]) >= 0)
        {
          this.elements.Add(this.source.Substring(prev_index, index - prev_index));
          this.elements.Add(new string(this.source[index], 1));

          prev_index = index + 1;
        }
      }

      if (prev_index != this.source.Length)
      {
        this.elements.Add(this.source.Substring(prev_index, this.source.Length - prev_index));
      }
      
      this.RemoveEmptyStrings();
    }

    private void RemoveEmptyStrings()
    {
      for (int index=0; index < this.elements.Count; index++)
        if ((string)this.elements[index]== "")
        {
          this.elements.RemoveAt(index);
          index--;
        }
    }
  }
}