Changeset 11370

Timestamp:

09/16/14 15:53:25 (10 years ago)

Author:

mkommend

Message:

#2220: Merged r11309 & r11347 into stable.

Location:

stable

Files:

• . (modified) (1 prop)
• HeuristicLab.Common/3.3/EnumerableExtensions.cs (modified) (1 diff)

stable/HeuristicLab.Common/3.3/EnumerableExtensions.cs

@@ -87 +87 @@
       return result;
     }
+
+    /// <summary>
+    /// Compute the n-ary cartesian product of arbitrarily many sequences: http://blogs.msdn.com/b/ericlippert/archive/2010/06/28/computing-a-cartesian-product-with-linq.aspx
+    /// </summary>
+    /// <typeparam name="T">The type of the elements inside each sequence</typeparam>
+    /// <param name="sequences">The collection of sequences</param>
+    /// <returns>An enumerable sequence of all the possible combinations of elements</returns>
+    public static IEnumerable<IEnumerable<T>> CartesianProduct<T>(this IEnumerable<IEnumerable<T>> sequences) {
+      IEnumerable<IEnumerable<T>> result = new[] { Enumerable.Empty<T>() };
+      return sequences.Where(s => s.Any()).Aggregate(result, (current, s) => (from seq in current from item in s select seq.Concat(new[] { item })));
+    }
   }
 }