We could always require and impose that the iterator also throw exceptions.

On 1/26/2011 12:20 PM, Steven Bethard (JIRA) wrote:
> EventStream should extend Iterator<Event>
> -----------------------------------------
>
>                  Key: OPENNLP-99
>                  URL: https://issues.apache.org/jira/browse/OPENNLP-99
>              Project: OpenNLP
>           Issue Type: New Feature
>           Components: Maxent
>     Affects Versions: maxent-3.0.0-sourceforge
>             Reporter: Steven Bethard
>
>
> [As requested, brought over from Sourceforge.]
>
> Conceptually, EventStream is just an Iterator<Event>. You would get better 
> interoperability with other Java libraries if EventStream were declared as 
> such. If you didn't care about backwards compatibility, I'd say just get rid 
> of EventStream entirely and use Iterator<Event> everywhere instead.
>
> If you care about backwards compatibility, you could at least declare 
> AbstractEventStream as implementing Iterator<Event> - it declares all of 
> hasNext(), next() and remove(). I believe that shouldn't break anything, and 
> should make all the current EventStream implementations into Iterator<Event>s.
>
> Why do I want this? Because, when using OpenNLP maxent from Scala, if a 
> RealValueFileEventStream were an Iterator<Event>, I could write:
>
>   for (event <- stream) {
>     ...
>   }
>
> But since it's not, I instead have to wrap it in an Iterator:
>
>   val events = new Iterator[Event] {
>     def hasNext = stream.hasNext
>     def next = stream.next
>   }
>   for (event <- events) {
>     ...
>   }
>
> Or write the while loop version:
>
>   while (stream.hasNext) {
>     val event = stream.next
>     ...
>   }
>
>

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