From: Massimiliano Mirra <list@...>
Date: 2002-10-23T18:13:45+09:00
Subject: Re: Sort::Versions (was Re: Perl multiple match RE in Ruby?)

On Tue, Oct 22, 2002 at 09:03:14PM +0900, Nikodemus Siivola wrote:
> > That would save the step of extending those classes in code.
> 
> How about adding that to the Version module inside a BuiltinExt module, so
> that to extend the classes you would just:

I'll throw mine in too; I wrote it for rpkg.  This makes Version a
Comparable object.  (Have a look at the tests for usage examples.)


class Version
  include Comparable

  def Version.[](*args)
    new(*args)
  end

  def initialize(s, separators = '.-')
    separators = separators.split('')

    items_regex_src = separators.collect {|sep| Regexp.escape(sep)}.join("|")
    seps_regex_src  = separators.collect {|sep| Regexp.escape(sep)}.join

    items_regex = Regexp.compile(items_regex_src)
    seps_regex = /[^#{seps_regex_src}]/
    
    @v = s.split(items_regex).collect {|n| Integer(n) rescue n}
    @sep = s.gsub(seps_regex, '').split('')
  end

  def to_a 
    @v
  end

  def to_s 
    s = ''
    @sep.each_with_index do |sep, i|
      s << "#{@v[i]}#{sep}"
    end
    s << "#{@v.last}"
    return s
  end

  def inspect 
    @v.inspect
  end

  def [](n)
    @v[n]
  end

  def <=>(other)
    raise unless other.is_a? Version
    
    comp = 0
    @v.each_with_index do |n, i|
      if n and other[i] 
        comp = n <=> other[i]
      elsif n.nil?
        comp = -1
      elsif other[i].nil?
        comp = +1
      else
        raise "This should never happen!"
      end
        
      if comp == 0
        next
      else
        break
      end
    end

    return comp     
  end
end


if $0 == __FILE__
  require 'test/unit'

  class Version
    def separators
      @sep
    end
  end
  
  class TestVersion < Test::Unit::TestCase
    def test_version_to_array
      v = Version['0.1.0']
      assert [0, 1, 0], v.to_a
    end

    def test_can_access_revision_number 
      v = Version['0.1.0']
      assert_equal 0, v[0]
      assert_equal 1, v[1]
      assert_equal 0, v[2]
    end

    def test_non_dot_separators 
      v = Version['0.1.0-20021099']
      
      assert_equal 0, v[2]
      assert_equal 20021099, v[3]
    end

    def test_can_mix_numbers_and_strings
      v = Version['0.1.4-unstable']

      assert_equal 0, v[0]
      assert_equal 1, v[1]
      assert_equal 4, v[2]
      assert_equal 'unstable', v[3]
    end
    
    def test_can_compare_equal_versions
      v1 = Version['0.1.0']
      v2 = Version['0.1.0']

      assert_equal v1 <=> v2, 0
      assert v1 == v2
      assert_equal v1, v2
    end

    def test_can_compare_different_versions
      v1 = Version['0.1.0']
      v2 = Version['0.1.2']

      assert_equal v1 <=> v2, -1
      assert_equal v2 <=> v1, 1
      assert v1 < v2
      assert v2 > v1
    end

    def test_can_compare_different_versions_with_different_number_of_items 
      v1 = Version['0.1.0']
      v2 = Version['0.1.0.2']

      assert v2 > v1

      v1 = Version['0.1.0']
      v2 = Version['0.1.0-20021010']

      assert v2 > v1
      
      v1 = Version['0.1.0']
      v2 = Version['0.1.0-unstable']

      assert v2 > v1
    end

    def test_can_reconstruct_version_string 
      s = '0.1.0-unstable-20021010'
      v = Version[s]

      assert_equal s, v.to_s
    end

    def test_finds_separators 
      s = '0.1.0-unstable-20021010'
      v = Version[s]

      assert_equal ['.', '.', '-', '-'], v.separators
    end

    def test_unique_version_item_accepted 
      v = Version['0123_done']

      assert_equal ["0123_done"], v.to_a      
    end

    def test_allow_alphabetic_only_versions 
      v = Version['cvs']

      assert_equal ["cvs"], v.to_a
    end
  end
end