Sort::MergeSort - merge pre-sorted input streams
use Sort::MergeSort; my $terator = mergesort($comparefunc, @iterators);
Given a comparison function and a bunch of iterators that produce data that is already sorted,
mergesort() will provide an iterator that produces sorted and merged data from all of the input iterators.
Sort::MergeSort also works with filehandles. It doesn't care. If it's only input is a filehandle, it will return a filehandle. In all other situations it will return an iterator.
$comparefunc takes two arguments. It does not use the implicit
$b that perl sort uses.
The iterators are treated as file handles so any filehandle or Sort::MergeSort::Iterator will do as input.