use IEnumertor or IEnumerable c# interface?

Question

I am porting some Java code to C# and my question is

One of my Java class declarations looks like this:

private class PseudoEnumeration implements Enumeration

Should this be translated to

private class PseudoEnumeration : IEnumerator

or

private class PseudoEnumeration : IEnumerable

and why each case?

Another thing is that the enumerator classes work differently in java and C#. Java has "hasMoreElements" and "nextElement" while C# uses "MoveNext" and "Current".

How would I port a Java function of this form to C#?

public boolean hasMoreElements() {
        return (field.hasMoreElements() );
    }

EDIT: I know MoveNext returns Bool if field has no more elements. However, it also advances the field to the enumerator to the next element. How do I just check if it has more elements without advancing the enumerator?

Answer 1

Given the current Enumeration implementation in Java, you should implement the IEnumerator<T> class, which is the class that enumerates over a collection and provides the methods better fitted to the Java counterpart.

MoveNext for example returns bool whether there actually is a next value in the enumeration, and relates to the hasMoreElements method of Java's Enumeration.

The IEnumerable<T> interface does not expose any of the details regarding the current state of the enumeration, like Current or MoveNext; it only exposes a GetEnumerator method that returns an IEnumerator<T> implementation for the given IEnumerable<T>.

Hence, it is the IEnumerator<T> class the one that exposes how to iterate over the collection, the current element, and whether there are more, similar to the Enumeration interface in Java.