tests/gtest-linq-08.cs

   1
   2
   3 using System;
   4
   5 class TestA
   6 {
   7         public string value;
   8
   9         public TestA (string value)
  10         {
  11                 this.value = value;
  12         }
  13
  14         public string Select<U> (Func<TestA, U> f)
  15         {
  16                 return value;
  17         }
  18 }
  19
  20 static class TestB
  21 {
  22         static public TestA Where(this TestA a, Func<TestA,bool> predicate)
  23         {
  24                 if (predicate (a))
  25                         return new TestA ("where used");
  26
  27                 return null;
  28         }
  29 }
  30
  31 public class CustomQueryExpressionPattern
  32 {
  33         static int Main ()
  34         {
  35                 var v = new TestA ("Oh yes");
  36                 string foo = from a in v select a;
  37                 if (foo != "Oh yes")
  38                         return 1;
  39
  40                 v = new TestA ("where?");
  41
  42                 // It also tests that select is not called in this case
  43                 v = from a in v where a.value != "wrong" select a;
  44
  45                 if (v.value != "where used")
  46                         return 1;
  47
  48                 Console.WriteLine (v.value.ToString ());
  49                 return 0;
  50         }
  51 }