Random Enumerators and Shufflers

The Shuffler class lets you shuffle the contents of any class that implements the ListT interface. This includes arrays, vectors and many other objects.

The class has only one static (Shared in Visual Basic) method, Shuffle, which is overloaded. The first overload takes two arguments: an ListT, and a Random that is used to generate the random sequence. This can be an instance of the Random itself, or one of the random number generators from the Extreme.Mathematics.Random namespace. The second variant only takes the list to shuffle, and uses a default random number generator.

int[] numbers = new int[] { 1, 2, 3, 4, 5, 6 };
Shuffler.Shuffle(numbers, new MersenneTwister());
for (int i = 0; i < numbers.Length; i++)
    Console.WriteLine(numbers[i]);

Dim numbers = {1, 2, 3, 4, 5, 6}
Shuffler.Shuffle(numbers, New MersenneTwister())
For i = 0 To numbers.Length - 1
    Console.WriteLine(numbers(i))
Next

let numbers = [| 1; 2; 3; 4; 5; 6 |]
Shuffler.Shuffle(numbers, MersenneTwister())
for number in numbers do
    printf "%d " number

These methods overwrite the contents of the list with the shuffled data.

The RandomizedCollectionT class is a generic wrapper for sequences that enumerates the elements of the sequence in random order. The following example enumerates the elements of an array in random order:

int[] numbers = new int[] { 1, 2, 3, 4, 5, 6 };
var randomized = new RandomizedCollection<int>(numbers);
foreach (int number in randomized)
    Console.WriteLine(number);

Dim numbers = {1, 2, 3, 4, 5, 6}
Dim randomized = New RandomizedCollection(Of Integer)(numbers)
For Each number In randomized
    Console.WriteLine(number)
Next

let numbers = [| 1; 2; 3; 4; 5; 6 |]
let randomized = RandomizedCollection<int>(numbers)
for number in randomized do
    printf "%d " number

RandomizedCollectionT works most efficiently with collections that implement the IListT interface, but can work with IEnumerableT sequences as well. In the latter case, all the values in the sequence are enumerated before the first random element is returned.