Why is movement only in most cases?

Question

I noticed that many iterators or data readers only go as DataReader , XmlReader , IEnumerator , many more (you got this idea).

So just ask why they are only for redirection usually when I create a data iterator for my custom needs. Usually I try to add support for navigation on both sides. I agree that most of the time we don’t need a backward movement, but sometimes we need it, and so we create variables tempor something that is needed to store data at runtime.

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So my questions are:

• Why do most data-iterators only forward

• I am mistaken when creating a reverse Iterator / Data iterator. if not, why does the infrastructure not support such support for embedded data Iterators.

• Do we have a serious lack of performance or just not , which is considered a good design to have such an opportunity.

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This question annoyed me very much, but I did not get a satisfactory answer, so I ask it here. I believe that many developers can agree with me that moving backwards can be useful sometimes.

Answer 1

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public static IEnumerable<int> LotsOfData() {
    var random = new Random();
    while(true) yield return random.Next();
}

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