Thursday, October 21, 2010

Collection Classes

using System;
using System.Collections;

// Declare the Tokens class:
public class Tokens : IEnumerable
{
private string[] elements;

Tokens(string source, char[] delimiters)
{
// Parse the string into tokens:
elements = source.Split(delimiters);
}

// IEnumerable Interface Implementation:
// Declaration of the GetEnumerator() method
// required by IEnumerable
public IEnumerator GetEnumerator()
{
return new TokenEnumerator(this);
}

// Inner class implements IEnumerator interface:
private class TokenEnumerator : IEnumerator
{
private int position = -1;
private Tokens t;

public TokenEnumerator(Tokens t)
{
this.t = t;
}

// Declare the MoveNext method required by IEnumerator:
public bool MoveNext()
{
if (position < t.elements.Length - 1)
{
position++;
return true;
}
else
{
return false;
}
}

// Declare the Reset method required by IEnumerator:
public void Reset()
{
position = -1;
}

// Declare the Current property required by IEnumerator:
public object Current
{
get
{
return t.elements[position];
}
}
}

// Test Tokens, TokenEnumerator

static void Main()
{
// Testing Tokens by breaking the string into tokens:
Tokens f = new Tokens("This is a well-done program.",
new char[] {' ','-'});
foreach (string item in f)
{
Console.WriteLine(item);
}

Console.ReadLine();
}
}

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