mcs/tests/test-iter-05.cs

   1 // Compiler options: -langversion:default
   2
   3 //
   4 // Use
   5
   6 using System;
   7 using System.Collections;
   8
   9 class X {
  10         static IEnumerable GetIt ()
  11         {
  12                 List l = new List (3);
  13                 l.Add (1);
  14                 l.Add (2);
  15                 l.Add (3);
  16
  17                 foreach (int i in l)
  18                         yield return i;
  19         }
  20
  21         public static int Main ()
  22         {
  23                 int total = 0;
  24                 foreach (int i in GetIt ()) {
  25                         Console.WriteLine ("Got: " + i);
  26                         total += i;
  27                 }
  28
  29                 return total == 6 ? 0 : 1;
  30         }
  31 }
  32
  33 public class List : IEnumerable {
  34
  35         int pos = 0;
  36         int [] items;
  37
  38         public List (int i)
  39         {
  40                 items = new int [i];
  41         }
  42
  43         public void Add (int value)
  44         {
  45                 items [pos ++] = value;
  46         }
  47
  48         public MyEnumerator GetEnumerator ()
  49         {
  50                 return new MyEnumerator(this);
  51         }
  52
  53         IEnumerator IEnumerable.GetEnumerator ()
  54         {
  55                 return GetEnumerator ();
  56         }
  57
  58         public struct MyEnumerator : IEnumerator {
  59
  60                 List l;
  61                 int p;
  62
  63                 public MyEnumerator (List l)
  64                 {
  65                         this.l = l;
  66                         p = -1;
  67                 }
  68
  69                 public object Current {
  70                         get {
  71                                 return l.items [p];
  72                         }
  73                 }
  74
  75                 public bool MoveNext()
  76                 {
  77                         return ++p < l.pos;
  78                 }
  79
  80                 public void Reset()
  81                 {
  82                         p = 0;
  83                 }
  84         }
  85 }