Custom Sequence Operator-Combine

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Custom Sequence Operator-Combine

This sample calculates the dot product of two integer vectors. It uses a user-created sequence operator, Combine, to calculate the dot product, passing it a lambda function to multiply two arrays, element by element, and sum the result.

Example:

public static class CustomSequenceOperators

{

    public static IEnumerable Combine(this IEnumerable first, IEnumerable second, Func func) {

        using (IEnumerator e1 = first.GetEnumerator(), e2 = second.GetEnumerator()) {

            while (e1.MoveNext() && e2.MoveNext()) {

                yield return func(e1.Current, e2.Current);

            }

        }

    }

}

public void Linq98() {

    int[] vectorA = { 0, 2, 4, 5, 6 };

    int[] vectorB = { 1, 3, 5, 7, 8 };



    int dotProduct = vectorA.Combine(vectorB, (a, b) => a * b).Sum();



    Console.WriteLine("Dot product: {0}", dotProduct);

}

Output:

Dot product: 109