Contents

#:title: Infinity
#--
# Infinity
# v 0.9
#
# Copyright (c) 2004,2005 Thomas Sawyer
# 
# Ruby License
#
# This module is free software. You may use, modify, and/or redistribute this
# software under the same terms as Ruby.
# 
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.
#
#
# $Id: infinity.rb,v 0.9 2005/04/28 17:00:24 transami Exp $
#
# ==========================================================================
# Revision History ::
# YYYY.MM.DD  Ver. Dev.      Description
# --------------------------------------------------------------------------
# 2005.04.28  0.9  Trans     * Minor modifications to documentation.
# ==========================================================================
#++

# = Description
#
# A full featured Infinity class, supporting aleph levels and signed 
# direction. Inifinty is a multiton based on the aleph and direction 
# values. The conastant INFINITY is provided as the common case with 
# aleph=0 and direction=+1 (positive).
# 
# = Author(s)
# 
# * Thomas Sawyer
# 

require 'facet/multiton'

class Infinity < Numeric
  VERSION = '0.9.0'

  include Multiton

  def self.[](a)
    self.new(a)
  end
  
  attr_reader :aleph, :direction
    
  def initialize(aleph=0, direction=1)
    @aleph = aleph
    @direction = direction
  end
  
  def -@
    self.class.instance(@aleph, @direction * -1)
  end
  
  def to_f
    (1.0/0) * @direction
  end
  
  def times
    loop do
      yield
    end
  end

  def <=>(x)
    return (x.kind_of?(Infinity) ? (@aleph <=> x.aleph) : @direction)
  end
  
  def to_s
    %Q{#{ '-' if @direction == -1 }Infinity[#{@aleph}]}
  end
  
end

# constant (for aleph=0)
INFINITY = Infinity.instance

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
facets-0.7.1	lib/facet/infinity.rb
facets-0.7.0	lib/facet/infinity.rb
facets-0.7.2	lib/facet/infinity.rb