Monthly Archives: February 2008

Authoring topic maps using Ruby-based DSL: CTM, the way I like it

Designing and using Domain Specific Languages (DSL) is a popular programming style in Ruby community.
I am experimenting with Ruby-based DSL for authoring topic maps. Surprisingly, the result is very close to
my view on the “ideal” CTM (Compact Topic Maps syntax).

I just would like to share a sample that should demonstrate main ideas of this approach. It is a piece of Ruby code that generates topic maps (behind the scenes).

First topic map defines some simple ontology.


# some definitions to support DSL
# should be included

topic_map :ontology_tm do
  
  tm_base "http://www.example.com/topic_maps/people/"

  topic(:person) {
    sid   "http://psi.example.com/Person"
    name  "Person"
    isa :topic_type
  }
  
  topic(:first_name) {
    sid   "http://psi.example.com/first_name"
    name  "first name"
    isa :name
  }

  topic(:last_name) {
    sid   "http://psi.example.com/last_name"
    name  "last name"
    isa :name
  }
  
  topic(:web_page) {
    sid   "http://psi.example.com/web_page"
    name  "web page"
    isa :occurrence
    datatype :uri
  }

  topic(:age) {
    sid   "http://psi.example.com/age"
    name  "age"
    isa :occurrence
    datatype :integer
  }
  
  topic(:description) {
    sid   "http://psi.example.com/description"
    name  "description"
    isa :occurrence
    datatype :string
  }
  
  topic(:works_for) {
    sid   "http://psi.example.com/works_for"
    name  "works for"
    isa :property
    association :employment
    first_role :employee
    second_role :employer
    third_role :position_type  
    third_role_prefix :as
  }
  
  topic(:likes) {
    sid   "http://psi.example.com/likes"
    name  "likes"
    isa [:property, :association]
    association :likes
    first_role :person
    second_role :object
  }
  
end

Second topic map includes ontology and asserts some facts.

	
topic_map :facts_tm do  
  
  tm_base "http://www.example.com/topic_maps/people/john_smith"

  tm_include :ontology_tm
 
  topic :john_smith do
      sid "http://psi.example.com/JohnSmith"
      name  "John Smith"
      name  "Johnny", :scope => :alt_name
      first_name "John" ; last_name  "Smith"
      web_page "http://a.example.com/JohnSmith.htm"
      works_for topic(:example_dot_com){
                              sid "http://www.example.com"
                              name "example.com"; isa :company
                         }, 
    	                :as => :program_manager, 
    	                :scope => :date_2008_02_28
      likes [:italian_opera, :new_york]
      age 35
      description <