class Version
  include Comparable

  attr_reader :major, :feature_group, :feature, :bugfix

  def initialize(version="")
    v = version.split(".")
    @major = v[0].to_i
    @feature_group = v[1].to_i
    @feature = v[2].to_i
    @bugfix = v[3].to_i
  end
  
  def <=>(other)
    return @major <=> other.major if ((@major <=> other.major) != 0)
    return @feature_group <=> other.feature_group if ((@feature_group <=> other.feature_group) != 0)
    return @feature <=> other.feature if ((@feature <=> other.feature) != 0)
    return @bugfix <=> other.bugfix
  end

  def self.sort
    self.sort!{|a,b| a <=> b}
  end

  def to_s
    @major.to_s + "." + @feature_group.to_s + "." + @feature.to_s + "." + @bugfix.to_s
  end
end

## Example Usage:
##  list = []
##  ["1.2.2.10","1.2.2.1","2.1.10.2","2.3.4.1"].each {|v| list.push(Version.new(v)) }
##  list.sort.each{|v| pp v.to_s }
##
###"1.2.2.1"
###"1.2.2.10"
###"2.1.10.2"
###"2.3.4.1"

Probably not the most elegant solution, but it works. Needed this for a capistrano deploy task which shows the most recent tagged releases in my repository. Very bare bones, and needs tweaking if your versions are not in X.X.X.X format.

Ruby class for easy version number natural order sorting

sort, number, ruby, order

Ruby