sfaleron

# Originally from http://logn.org/2009/07/lazy-primes-sieve-in-python.html
# Updated for Python3 by Chris Fuller.

# The automated 2to3 translation doesn't work. The tricky bit is the heap item.
# This is a (int, object) tuple in the original module, but the second element
# becomes a map iterator in Python3, which does not compare, so an exception
# is raised when the heap is sorted.

# It turns out that the object in the original tuple is irrelevant to the sort
# (it compares by memory location, which isn't well defined!). The int deter-