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 index;
  18                 private int length;
  19
  20                 // Constructor
  21                 internal CharEnumerator (string s)
  22                 {
  23                          str = s;
  24                          index = -1;
  25                          length = s.Length;
  26                 }
  27
  28                 // Property
  29                 public char Current
  30                 {
  31                         get {
  32                                 if (index == -1)
  33                                         throw new InvalidOperationException
  34                                                 ("The position is not valid.");
  35
  36                                 return str [index];
  37                         }
  38                 }
  39
  40                 object IEnumerator.Current
  41                 {
  42                         get {
  43                                 if (index == -1)
  44                                         throw new InvalidOperationException
  45                                                 ("The position is not valid");
  46
  47                                 return str [index];
  48                         }
  49                 }
  50
  51                 // Methods
  52                 public object Clone ()
  53                 {
  54                         CharEnumerator x = new CharEnumerator (str);
  55                         x.index = index;
  56                         return x;
  57                 }
  58
  59                 public bool MoveNext ()
  60                 {
  61                         if (length == 0)
  62                                 return false;
  63
  64                         index ++;
  65
  66                         if (index == length)
  67                                 return false;
  68                         else
  69                                 return true;
  70                 }
  71
  72                 public void Reset ()
  73                 {
  74                         index = -1;
  75                 }
  76         }
  77 }