Is there a better alternative than this to 'switch on type'?

Question

Seeing as C# can\'t switch on a Type (which I gather wasn\'t added as a special case because is relationships mean that more than one distinct

Answer 1

With JaredPar's answer in the back of my head, I wrote a variant of his TypeSwitch class that uses type inference for a nicer syntax:

class A { string Name { get; } }
class B : A { string LongName { get; } }
class C : A { string FullName { get; } }
class X { public string ToString(IFormatProvider provider); }
class Y { public string GetIdentifier(); }

public string GetName(object value)
{
    string name = null;
    TypeSwitch.On(value)
        .Case((C x) => name = x.FullName)
        .Case((B x) => name = x.LongName)
        .Case((A x) => name = x.Name)
        .Case((X x) => name = x.ToString(CultureInfo.CurrentCulture))
        .Case((Y x) => name = x.GetIdentifier())
        .Default((x) => name = x.ToString());
    return name;
}

Note that the order of the Case() methods is important.

---

Get the full and commented code for my TypeSwitch class. This is a working abbreviated version:

public static class TypeSwitch
{
    public static Switch On(TSource value)
    {
        return new Switch(value);
    }

    public sealed class Switch
    {
        private readonly TSource value;
        private bool handled = false;

        internal Switch(TSource value)
        {
            this.value = value;
        }

        public Switch Case(Action action)
            where TTarget : TSource
        {
            if (!this.handled && this.value is TTarget)
            {
                action((TTarget) this.value);
                this.handled = true;
            }
            return this;
        }

        public void Default(Action action)
        {
            if (!this.handled)
                action(this.value);
        }
    }
}