C# Extension Methods - How far is too far?

Question

Rails introduced some core extensions to Ruby like 3.days.from_now which returns, as you'd expect a date three days in the future. With extension methods in C# we can now do something similar:

static class Extensions
{
    public static TimeSpan Days(this int i)
    {
        return new TimeSpan(i, 0, 0, 0, 0);
    }

    public static DateTime FromNow(this TimeSpan ts)
    {
        return DateTime.Now.Add(ts);
    }
}

class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine(
            3.Days().FromNow()
        );
    }
}

Or how about:

static class Extensions
{
    public static IEnumerable<int> To(this int from, int to)
    {
        return Enumerable.Range(from, to - from + 1);
    }
}

class Program
{
    static void Main(string[] args)
    {
        foreach (var i in 10.To(20))
        {
            Console.WriteLine(i);
        }
    }
}

Is this fundamentally wrong, or are there times when it is a good idea, like in a framework like Rails?

Answer 1

Each language has its own perspective on what a language should be. Rails and Ruby are designed with their own, very distinct opinions. PHP has clearly different opinions, as does C(++/#)...as does Visual Basic (though apparently we don't like their style).

The balance is having many, easily-read, built-in functions vs. the nitty-gritty control over everything. I wouldn't want SO many functions that you have to go to a lookup every time you want to do anything (and there's got to be a performance overhead to a bloated framework), but I personally love Rails, because what it has saves me a lot of time developing.

I guess what I'm saying here is that if you were designing a language, take a stance, go from there, and build in the functions you (or your target developer would) use most often.