mcs/class/corlib/System/CharEnumerator.cs

   1 //
   2 // System.CharEnumerator.cs
   3 //
   4 // Author: Duncan Mak  (duncan@ximian.com)
   5 //
   6 // (C) Ximian, Inc.
   7 //
   8
   9 using System.Collections;
  10
  11 namespace System
  12 {
  13            [Serializable]
  14            public sealed class CharEnumerator : IEnumerator, ICloneable
  15            {
  16                  private string str;
  17                  private int idx;
  18
  19            // Constructor
  20                  internal CharEnumerator (string s)
  21                  {
  22                             str = s;
  23                             idx = -1;
  24                  }
  25
  26                  // Property
  27                  public char Current
  28                  {
  29                             get {
  30                                   if (idx == -1)
  31                                                 throw new InvalidOperationException ("The position is not valid.");
  32
  33                                   return str[idx];
  34                             }
  35                  }
  36
  37                  object IEnumerator.Current {
  38                             get {
  39                                           if (idx == -1)
  40                                                         throw new InvalidOperationException ("The position is not valid");
  41                                           return str [idx];
  42                             }
  43                  }
  44
  45                  // Methods
  46                  public object Clone ()
  47                  {
  48                             CharEnumerator x = new CharEnumerator (str);
  49                             x.idx = idx;
  50                             return x;
  51                  }
  52
  53                  public bool MoveNext ()
  54                  {
  55                             if (idx > str.Length) {
  56                                           idx = -1;
  57                                           return false;
  58                             } else
  59                                           return true;
  60                  }
  61
  62                  public void Reset ()
  63                  {
  64                             idx = 0;
  65                  }
  66    }
  67 }