Mega Code Archive

 

Categories / C# / Collections Data Structure

 

Compares two sequences

//GNU General Public License version 2 (GPLv2) //http://dotwayutilities.codeplex.com/license using System.Collections.Generic; namespace Dotway.BuildTasks.Utils {     /// <summary>     /// Compares two sequences.     /// </summary>     /// <typeparam name="T">Type of item in the sequences.</typeparam>     /// <remarks>     /// Compares elements from the two input sequences in turn. If we     /// run out of list before finding unequal elements, then the shorter     /// list is deemed to be the lesser list.     /// </remarks>     public class EnumerableComparer<T> : IComparer<IEnumerable<T>>     {         /// <summary>         /// Object used for comparing each element.         /// </summary>         private readonly IComparer<T> comp;         /// <summary>         /// Create a sequence comparer using the default comparer for T.         /// </summary>         public EnumerableComparer()         {             comp = Comparer<T>.Default;         }         /// <summary>         /// Create a sequence comparer, using the specified item comparer         /// for T.         /// </summary>         /// <param name="comparer">Comparer for comparing each pair of         /// items from the sequences.</param>         public EnumerableComparer(IComparer<T> comparer)         {             comp = comparer;         }         #region IComparer<IEnumerable<T>> Members         /// <summary>         /// Compare two sequences of T.         /// </summary>         /// <param name="x">First sequence.</param>         /// <param name="y">Second sequence.</param>         public int Compare(IEnumerable<T> x, IEnumerable<T> y)         {             using (IEnumerator<T> leftIt = x.GetEnumerator())             using (IEnumerator<T> rightIt = y.GetEnumerator())             {                 while (true)                 {                     bool left = leftIt.MoveNext();                     bool right = rightIt.MoveNext();                     if (!(left || right)) return 0;                     if (!left) return -1;                     if (!right) return 1;                     int itemResult = comp.Compare(leftIt.Current, rightIt.Current);                     if (itemResult != 0) return itemResult;                 }             }         }         #endregion     } }