How could I take 1 more item from Linq's TakeWhile?

Question

(line of code of interest is the last one, the rest is just for a full representation)

Using the following code, I wanted to take VOTERS until I exceeded

Answer 1

Just write your own extension method:

static class IEnumerableExtensions {
    public static IEnumerable TakeUntil(
        this IEnumerable elements,
        Func predicate
    ) {
        return elements.Select((x, i) => new { Item = x, Index = i })
                       .TakeUntil((x, i) => predicate(x.Item))
                       .Select(x => x.Item);
    }

    public static IEnumerable TakeUntil(
        this IEnumerable elements,
        Func predicate
    ) {
        int i = 0;
        foreach (T element in elements) {
            if (predicate(element, i)) {
                yield return element;
                yield break;
            }
            yield return element;
            i++;
        }
    }
}

Usage:

var eligibleVoters = voters.TakeUntil(
                         p => (voicesSoFar += p.Voices) >= voicesNeeded
                     );

foreach(var voter in eligibleVoters) {
    Console.WriteLine(voter.Name);
}

Output:

Alice
Bob
Catherine