2011/6/22 Phillip Gawlowski <cmdjackryan / googlemail.com>:
> I suspect you want to output this hash ordered by priority, correct?

Not exactly. Well, not at all in fact :)

Being more explicit, I use em-udns library ang perform a DNS SRV query
for a domain, and get an array of one1 or more
EventMachine::Udns::RR_SRV instances. Each object has a priority value
(and also weight, but I don't care it now):

  https://github.com/ibc/em-udns

Note that priorities don't need to be correlated, this is, there could
be 4 entries with these priorities:
- 1   => A
- 10 => B
- 1   => C
- 3   => D

I just want to get an ordered hash in which:

- The key is the priority (in the given example there would be 3
entries: 1, 3 and 10).
- The value is an array with all the valus with such priority.

So, what I want to get is:

{
  1   => [A, C],
  3   => [D],
  10 => [B]
}


What I do know is:

- Get the DNS result array:

    srvs = [ object1, object2, object3, object4 ]

- Order the array based on Object#priority.

     srvs.sort_by{|e| e.priority}

- Construct the hash:

    ordered_hash = {}
    srvs.sort_by{|e| e.priority}.each do |srv|
      ordered_hash[srv.priority| ||= []
      ordered_hash[srv.priority| << srv.value
    end


It just works. Initially I tryed a different approach so my original
question was a bit different.



-- 
Iñaki Baz Castillo
<ibc / aliax.net>