Datum conversion, XML to JSON, using wongi-engine rule system

xml_to_json_machine.rb

#!/usr/bin/env ruby

require 'wongi-engine'
require 'uuid'

engine = Wongi::Engine.create
uuid = UUID.generate.to_sym
engine << [ uuid, :semantic_type, :person                                                 ]
engine << [ uuid, :media_type,    :'application/xml'                                      ]
engine << [ uuid, :value,         '<person id="1"><name>Anthony Bargnesi</name></person>' ]
uuid = UUID.generate.to_sym
engine << [ uuid, :semantic_type, :person                                                 ]
engine << [ uuid, :media_type,    :'application/xml'                                      ]
engine << [ uuid, :value,         '<person id="1"><name>Anthony Bargnesi</name></person>' ]

apply_cmd = open('|components/xml_to_js/apply', 'r+')
engine.rule 'xml_to_json' do
  for_all {
    has :Datum,   :semantic_type, :SemanticType
    has :Datum,   :media_type,    :'application/xml'
    has :Datum,   :value,         :Value
    assign :OutValue do |token|
      apply_cmd.puts(token[:Value])
      apply_cmd.gets
    end
  }
  do! {
    uuid = UUID.generate.to_sym
    puts "generated json for #{uuid}"
    gen uuid,  :semantic_type, :SemanticType
    gen uuid,  :media_type,    :'application/json'
    gen uuid,  :value,         :OutValue
  }
end

engine.query 'value' do
  search_on :Media_type
  forall {
    has :Datum, :media_type,    :Media_type
    has :Datum, :_,             :_
  }
end

engine.execute 'value', { Media_type: :'application/json' }

engine.results['value'].tokens.each do |token|
  puts token.wme
end

apply_cmd.close

# Output:
#=> generated json for 59054250-3acd-0133-3b55-082e5f8a66ae
#=> {:"59054250-3acd-0133-3b55-082e5f8a66ae" emantic_type erson}
#=> {:"59054250-3acd-0133-3b55-082e5f8a66ae" :media_type :"application/json"}
#=> {:"59054250-3acd-0133-3b55-082e5f8a66ae" :value "{\"person\":{\"name\":\"Anthony Bargnesi\",\"id\":1}}\n"}

xml_to_json_machine_2.rb

#!/usr/bin/env ruby

require 'wongi-engine'
require 'uuid'

engine = Wongi::Engine.create
engine << [ 'A', :semantic_type, :personA                                                 ]
engine << [ 'A', :media_type,    :'application/xml'                                      ]
engine << [ 'A', :value,         '<person id="1"><name>Anthony Bargnesi</name></person>' ]
engine << [ 'B', :semantic_type, :personB                                                 ]
engine << [ 'B', :media_type,    :'application/xml'                                      ]
engine << [ 'B', :value,         '<person id="1"><name>Anthony Bargnesi</name></person>' ]

apply_cmd = open('|components/xml_to_js/apply', 'r+')
engine.rule 'xml_to_json' do
  for_all {
    has :Datum,   :semantic_type, :SemanticType
    has :Datum,   :media_type,    :'application/xml'
    has :Datum,   :value,         :Value
    assign :OutValue do |token|
      apply_cmd.puts(token[:Value])
      apply_cmd.gets.chomp
    end
    assign :NewDatum do |token|
      UUID.generate
    end
  }
  make {
    # NewDatum is different for each matched fact?
    gen :NewDatum,  :semantic_type, :SemanticType
    gen :NewDatum,  :media_type,    :'application/json'
    gen :NewDatum,  :value,         :OutValue
  }
end

engine.query 'value' do
  search_on :Media_type
  forall {
    has :Datum, :media_type,    :Media_type
    has :Datum, :_,             :_
  }
end

puts engine.select(:_, :_, :_)
puts "-----"

engine.execute 'value', { Media_type: :'application/json' }

engine.results['value'].tokens.each do |token|
  puts token.wme
end

apply_cmd.close

xml_to_json_machine_3.rb

#!/usr/bin/env ruby
require 'wongi-engine'
require 'uuid'
engine = Wongi::Engine.create

id      = UUID.generate
engine << [ id, :semantic_type, :person                                                 ]
engine << [ id, :media_type,    :'application/xml'                                      ]
engine << [ id, :value,         '<person id="1"><name>Anthony Bargnesi</name></person>' ]
id      = UUID.generate
engine << [ id, :semantic_type, :person                                                 ]
engine << [ id, :media_type,    :'application/xml'                                      ]
engine << [ id, :value,         '<person id="2"><name>Anthony Bargnesi</name></person>' ]

puts "Facts:"
engine.wmes.map { |fact|
  puts fact
}
puts "\n"

apply_cmd = open('|components/xml_to_js/apply', 'r+')

engine.rule 'xml_to_json' do
  for_all {
    has :Datum,   :semantic_type, :SemanticType
    has :Datum,   :media_type,    :'application/xml'
    has :Datum,   :value,         :Value
  }
  make {
    action { |token|
      # Manually set token assignments for each match of fact set.
      # This works (but kludgy) whereas using 'assign' clause within 'for_all'  did not.
      # The effect there was only one call to make would occur for each matched set.
      apply_cmd.puts(token[:Value])

      id        = UUID.generate
      new_value = apply_cmd.gets.chomp
      token.assignments[:OutValue] = Proc.new { new_value }
      token.assignments[:NewDatum] = Proc.new { id        }
    }
    gen :NewDatum,  :semantic_type, :SemanticType
    gen :NewDatum,  :media_type,    :'application/json'
    gen :NewDatum,  :value,         :OutValue
  }
end

engine.query 'value' do
  search_on :Media_type
  forall {
    has :Datum, :media_type,    :Media_type
    has :Datum, :_,             :_
  }
end

engine.execute 'value', { Media_type: :'application/json' }

puts %Q{Results of 'value' query for [ :Datum :media_type :application/json ]}
engine.results['value'].tokens.each do |token|
  puts token.wme
end

apply_cmd.close

The outputted results for the value query does not have two UUID subjects as I was expecting. The rule xml_to_json only processes one set of facts in the do! block.

The second example makes the new subject an assign variable construct. A NewDatum variable is created for each matched fact whereas I thought I would get one NewDatum variable for the full set of matched facts.

The third example seems to work thought its kludgy.