C#/EnumerableFlatten.cs

   1 using System.Collections.Generic;
   2
   3 namespace IEnumerableExtras
   4 {
   5     /// <summary>
   6     /// Provides <see cref="IEnumerable{T}"/> with Flatten extension method.
   7     /// </summary>
   8     public static class EnumerableFlatten
   9     {
  10         /// <summary>
  11         /// Flatten two-tier collection into one-tier collection.
  12         /// </summary>
  13         /// <typeparam name="T"></typeparam>
  14         /// <param name="collection"></param>
  15         /// <returns></returns>
  16         public static IEnumerable<T> Flatten< T >( this IEnumerable<IEnumerable<T>> collection )
  17         {
  18             foreach ( var enumerable in collection )
  19             {
  20                 if ( enumerable != null )
  21                 {
  22                     foreach ( var item in enumerable )
  23                     {
  24                         yield return item;
  25                     }
  26                 }
  27             }
  28         }
  29     }
  30 }