If it were me, rather than monkey patching array I'd be tempted introduce a new dedicated Heap class that implements existing API (push, pop, <<, shift) so that it's closer to existing Array and Queue implementations instead of adding dedicated heap_push, heap_pop, etc..
As well as better duck typing this allows introspection via .is_a? and case statements.
Also I wonder if it would be useful to base the implementation on the Queue[1] rather than Array to maintain thread safety.
There is something satisfying about using an array like Python. It's very straightforward and doesn't require you to convert back and forth between a queue and a array.
That's an interesting idea to use Queue. I do need random access to implement the binary queue, so I'm not sure if Queue would work.
1. https://github.com/florian/rb_heap 2. https://github.com/kanwei/algorithms
