source: trunk/sources/LibSVM/SupportClass.cs @ 1913

//
// In order to convert some functionality to Visual C#, the Java Language Conversion Assistant
// creates "support classes" that duplicate the original functionality.  
//
// Support classes replicate the functionality of the original code, but in some cases they are 
// substantially different architecturally. Although every effort is made to preserve the 
// original architecture of the application in the converted project, the user should be aware that 
// the primary goal of these support classes is to replicate functionality, and that at times 
// the architecture of the resulting solution may differ somewhat.
//

using System;

/// <summary>
/// Contains conversion support elements such as classes, interfaces and static methods.
/// </summary>
public class SupportClass
{
  //Provides access to a static System.Random class instance
  static public System.Random Random = new System.Random();

  /*******************************/
  /// <summary>
  /// The class performs token processing in strings
  /// </summary>
  public class Tokenizer: System.Collections.IEnumerator
  {
    /// Position over the string
    private long currentPos = 0;

    /// Include demiliters in the results.
    private bool includeDelims = false;

    /// Char representation of the String to tokenize.
    private char[] chars = null;
      
    //The tokenizer uses the default delimiter set: the space character, the tab character, the newline character, and the carriage-return character and the form-feed character
    private string delimiters = " \t\n\r\f";    

    /// <summary>
    /// Initializes a new class instance with a specified string to process
    /// </summary>
    /// <param name="source">String to tokenize</param>
    public Tokenizer(System.String source)
    {     
      this.chars = source.ToCharArray();
    }

    /// <summary>
    /// Initializes a new class instance with a specified string to process
    /// and the specified token delimiters to use
    /// </summary>
    /// <param name="source">String to tokenize</param>
    /// <param name="delimiters">String containing the delimiters</param>
    public Tokenizer(System.String source, System.String delimiters):this(source)
    {     
      this.delimiters = delimiters;
    }


    /// <summary>
    /// Initializes a new class instance with a specified string to process, the specified token 
    /// delimiters to use, and whether the delimiters must be included in the results.
    /// </summary>
    /// <param name="source">String to tokenize</param>
    /// <param name="delimiters">String containing the delimiters</param>
    /// <param name="includeDelims">Determines if delimiters are included in the results.</param>
    public Tokenizer(System.String source, System.String delimiters, bool includeDelims):this(source,delimiters)
    {
      this.includeDelims = includeDelims;
    } 


    /// <summary>
    /// Returns the next token from the token list
    /// </summary>
    /// <returns>The string value of the token</returns>
    public System.String NextToken()
    {       
      return NextToken(this.delimiters);
    }

    /// <summary>
    /// Returns the next token from the source string, using the provided
    /// token delimiters
    /// </summary>
    /// <param name="delimiters">String containing the delimiters to use</param>
    /// <returns>The string value of the token</returns>
    public System.String NextToken(System.String delimiters)
    {
      //According to documentation, the usage of the received delimiters should be temporary (only for this call).
      //However, it seems it is not true, so the following line is necessary.
      this.delimiters = delimiters;

      //at the end 
      if (this.currentPos == this.chars.Length)
        throw new System.ArgumentOutOfRangeException();
      //if over a delimiter and delimiters must be returned
      else if (   (System.Array.IndexOf(delimiters.ToCharArray(),chars[this.currentPos]) != -1)
             && this.includeDelims )                  
        return "" + this.chars[this.currentPos++];
      //need to get the token wo delimiters.
      else
        return nextToken(delimiters.ToCharArray());
    }

    //Returns the nextToken wo delimiters
    private System.String nextToken(char[] delimiters)
    {
      string token="";
      long pos = this.currentPos;

      //skip possible delimiters
      while (System.Array.IndexOf(delimiters,this.chars[currentPos]) != -1)
        //The last one is a delimiter (i.e there is no more tokens)
        if (++this.currentPos == this.chars.Length)
        {
          this.currentPos = pos;
          throw new System.ArgumentOutOfRangeException();
        }
      
      //getting the token
      while (System.Array.IndexOf(delimiters,this.chars[this.currentPos]) == -1)
      {
        token+=this.chars[this.currentPos];
        //the last one is not a delimiter
        if (++this.currentPos == this.chars.Length)
          break;
      }
      return token;
    }

        
    /// <summary>
    /// Determines if there are more tokens to return from the source string
    /// </summary>
    /// <returns>True or false, depending if there are more tokens</returns>
    public bool HasMoreTokens()
    {
      //keeping the current pos
      long pos = this.currentPos;
      
      try
      {
        this.NextToken();
      }
      catch (System.ArgumentOutOfRangeException)
      {       
        return false;
      }
      finally
      {
        this.currentPos = pos;
      }
      return true;
    }

    /// <summary>
    /// Remaining tokens count
    /// </summary>
    public int Count
    {
      get
      {
        //keeping the current pos
        long pos = this.currentPos;
        int i = 0;
      
        try
        {
          while (true)
          {
            this.NextToken();
            i++;
          }
        }
        catch (System.ArgumentOutOfRangeException)
        {       
          this.currentPos = pos;
          return i;
        }
      }
    }

    /// <summary>
    ///  Performs the same action as NextToken.
    /// </summary>
    public System.Object Current
    {
      get
      {
        return (Object) this.NextToken();
      }   
    }   
    
    /// <summary>
    //  Performs the same action as HasMoreTokens.
    /// </summary>
    /// <returns>True or false, depending if there are more tokens</returns>
    public bool MoveNext()
    {
      return this.HasMoreTokens();
    }
    
    /// <summary>
    /// Does nothing.
    /// </summary>
    public void  Reset()
    {
      ;
    }     
  }
}