Thoughts on foreach with Enumerable.Range vs traditional for loop

This is just for fun. (I'd just use the standard "for (int i = 1; i <= 10; i++)" loop format myself.)

foreach (int i in 1.To(10))
{
    Console.WriteLine(i);    // 1,2,3,4,5,6,7,8,9,10
}

// ...

public static IEnumerable<int> To(this int from, int to)
{
    if (from < to)
    {
        while (from <= to)
        {
            yield return from++;
        }
    }
    else
    {
        while (from >= to)
        {
            yield return from--;
        }
    }
}

You could also add a Step extension method too:

foreach (int i in 5.To(-9).Step(2))
{
    Console.WriteLine(i);    // 5,3,1,-1,-3,-5,-7,-9
}

// ...

public static IEnumerable<T> Step<T>(this IEnumerable<T> source, int step)
{
    if (step == 0)
    {
        throw new ArgumentOutOfRangeException("step", "Param cannot be zero.");
    }

    return source.Where((x, i) => (i % step) == 0);
}

I find the latter's "minimum-to-maximum" format a lot clearer than Range's "minimum-count" style for this purpose. Also, I don't think it's really a good practice to make a change like this from the norm that is not faster, not shorter, not more familiar, and not obviously clearer.

That said, I'm not against the idea in general. If you came up to me with syntax that looked something like foreach (int x from 1 to 8) then I'd probably agree that that would be an improvement over a for loop. However, Enumerable.Range is pretty clunky.


In C# 6.0 with the use of

using static System.Linq.Enumerable;

you can simplify it to

foreach (var index in Range(1, 7))
{
    Console.WriteLine(index);
}