[collections] Re: /PROPOSAL 1/ Additions to IteratorUtils

[__matthewHawthorne]

( Remember to prefix subject with [collections] )

In the current CVS HEAD, you can do

IteratorUtils.toArray(Iterator).length
or
IteratorUtils.toList(Iterator).size()
But, your suggestion may be a good addition also.

Also, I think that the method definitions you've provided will all cause 
infinite loops -- hasNext() will always return true if you don't call 
next().  We'd need to find a way to copy the iterator so we don't modify 
it's state when we count the elements.

Anyone else have an opinion?



Lee Crawford wrote:
I'd like to propose the following simple additions to the
o.a.c.c.IteratorUtils
class. 

The following is a simple convenience method for counting the number of
elements
in an iteration, something that I find myself recreating somewhat
frequently: 

  public static
  int countElements (final Iterator iter) {
    int cnt = 0; 
    while (iter.hasNext ()) { 
      cnt ++; 
    }
    return cnt; 
  }

There isn't an EnumeratorUtils present that might contain an equivalent:

  public static
  int countElements (final Enumerator enum) {
    int cnt = 0; 
    while (enum.hasNext ()) { 
      cnt ++; 
    }
    return cnt; 
  }

Or the slightly less performant: 

  public static
  int countElements (final Enumerator enum) {
    return IteratorUtils.countElements (asIterator (enum)); 
  }

Thoughts? 

--lee


---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]