Is it possible to implement a recursive “SelectMany”?

Question

As we all know, Enumerable.SelectMany flattens a sequence of sequences into a single sequence. What if we wanted a method that could flatten sequences of sequen

Answer 1

As far as I understood your idea, this is my variant:

static IEnumerable Flatten(IEnumerable collection)
{
    foreach (var o in collection)
    {
        if (o is IEnumerable && !(o is T))
        {
            foreach (T t in Flatten((IEnumerable)o))
                yield return t;
        }
        else
            yield return (T)o;
    }
}

and check it

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