That would be grep ;-) Still, that can be pretty wasteful. Why iterate over the entire 10,000,000 records even when the single one of interest is found at the very beginning? The iterators do not offer any early bailing mechanism.

You have to look at the larger picture.

Iterators mainly offer convenience. There are very few situations where iterators are useful under big efficiency concerns (be it memory or time), in the absence of lazy lists. Even so, you can't go wrong with the explicit loop construct.

This ain't Ruby. :-) Perl 6 will, however, have lazy lists. (Is there anything Perl 6 won't fix? :-))

Makeshifts last the longest.