From: itsme213 <itsme213@...>
Date: 2006-03-25T00:23:52+09:00
Subject: Suggestion for Ruby quiz

Integration of OWL with Ruby

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OWL (Web Ontology Language) has several interesting capabilities, including:
- Define a (possibly anonymous) class using property expressions
   DarkChocolate = Dark & base_material is a Chocolate
   Dark = (any Thing) with brightness = Low
- Class definition can be incremental and federated
   Vehicle = ....
   ...
   Vehicle = ....
- Classification
   Determine if arbitrary object is member of class by checking properties
- Equivalent | Disjoint | ...
   Assert that two separately defined classes always | never have the same 
members
- First-class properties
   Properties are applicable to independent classes (duck typing)
   Properties are namespaced (Ruby 2 forthcoming selector namespace)
- Numerous tools
   There are many (open-source) tools that handle OWL ontologies
- Formal interpretation
   Maps to RDF tuples (subject-predicate-object)
   Makes many (open-source) formal analysis tools applicable

Tons of info on OWL on the web. One tutorial at 
http://www.cs.man.ac.uk/~horrocks/ISWC2003/Tutorial/

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A deep integration of OWL with Ruby would be interesting and potentially 
very useful:
 - opening up new kinds of expressiveness in Ruby
 - allowing all of Ruby's power in manipulating OWL
 - opening access to OWL and RDF tools.

One might even find some intriguing links between some of OWL's features and 
Ruby with duck typing, open classes, method_missing, dynamic mix-ins, etc. 
(See http://gigaton.thoughtworks.net/~ofernand1/DeepIntegration.pdf)

An example of integrating OWL and Ruby, adapted from the above URL:

class TeachersChild < OWL::Thing

  defined_with_query some_expression_or_block_or_string

  def misbehave
    raise "Teacher's kids never misbehave"
  end

end

obj1 = OWL::Thing.new (properties which may qualify as TeachersChild)

obj1.misbehave # dynamically pick up TeachersChild#misbehave

ExternalOWLTool.process obj1 # external reasoning tools

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There may be some useful Ruby resources already available based on work by 
Rich Kilmer.
www.daml.org/meetings/2004/05/pi/pdf/InfoEther-Semitar.pdf