More about iterator

[Tony Johansson]

Hello!

I have noticed that I can use iterator in a method and return an IEnumerable
like this
public IEnumerable<TReverse()
{
for (int i = data.Count -1 ; i >=0 ; i--)
yield return data[i];
}

I can test this Reverse by having this code
foreach (string word in bc.Reverse())
Console.WriteLine(word);

Now to my question If I instead have defined the Reverse method like this
public IEnumerator<TReverse()
{
for (int i = data.Count -1 ; i >=0 ; i--)
yield return data[i];
}
having IEnumerator as the return type I get compile
error saying "foreach statement cannot operate on variables of type
'System.Collections.Generic.IEnumerator<string>' because
'System.Collections.Generic.IEnumerator<string>' does not contain a public
definition for 'GetEnumerator'"

So I wonder how is the connection between a returning type for IEnumerable
and IEnumerator for a method using iterator and the statement call that is
used after the in keword in a foreach loop construction.

//Tony