From: Mark Thomas <ruby@...>
Date: 2008-06-24T23:08:06+09:00
Subject: Re: Reorder a XML file by distance from a location


> thanks, but my problem is not with the distance, but merely sorting
> stuff. If you tell me how to sort alphabetically, or by latitude or
> longitude, I would be very happy already.

The easy way is to include Comparable in a class:

class Location
  include Comparable
  attr_accessor :title, :desc, :link, :lat, :long, :distance

  def <=>(other)
    distance <=> other.distance
  end

  def to_s
    title
  end
end

With the above class, you'd be able to do stuff like this:

near = Location.new
near.title = "Near"
near.lat = 45.3
near.long = 130.2
near.distance = calculate_distance(near.lat, near.long)

far = Location.new
far.title = "Far"
far.lat = 20.7
far.long = 129.0
far.distance = calculate_distance(near.lat, near.long)

puts [far, near].sort  # => Near, Far