Class: KBS::Engine

Inherits:
Object
  • Object
show all
Defined in:
lib/kbs/engine.rb

Direct Known Subclasses

Blackboard::Engine

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Engine

Returns a new instance of Engine.



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# File 'lib/kbs/engine.rb', line 7

def initialize
  @working_memory = WorkingMemory.new
  @rules = []
  @alpha_memories = {}
  @production_nodes = {}
  @root_beta_memory = BetaMemory.new

  # Add initial dummy token to root beta memory
  # This represents "no conditions matched yet" and allows the first condition to match
  @root_beta_memory.add_token(Token.new(nil, nil, nil))

  @working_memory.add_observer(self)
end

Instance Attribute Details

#alpha_memories ⇒ Object (readonly)

Returns the value of attribute alpha_memories.



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# File 'lib/kbs/engine.rb', line 5

def alpha_memories
  @alpha_memories
end

#production_nodes ⇒ Object (readonly)

Returns the value of attribute production_nodes.



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# File 'lib/kbs/engine.rb', line 5

def production_nodes
  @production_nodes
end

#rules ⇒ Object (readonly)

Returns the value of attribute rules.



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# File 'lib/kbs/engine.rb', line 5

def rules
  @rules
end

#working_memory ⇒ Object (readonly)

Returns the value of attribute working_memory.



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# File 'lib/kbs/engine.rb', line 5

def working_memory
  @working_memory
end

Instance Method Details

#add_fact(type, attributes = {}) ⇒ Object 



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# File 'lib/kbs/engine.rb', line 26

def add_fact(type, attributes = {})
  fact = Fact.new(type, attributes)
  @working_memory.add_fact(fact)
  fact
end

#add_rule(rule) ⇒ Object 



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# File 'lib/kbs/engine.rb', line 21

def add_rule(rule)
  @rules << rule
  build_network_for_rule(rule)
end

#remove_fact(fact) ⇒ Object 



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# File 'lib/kbs/engine.rb', line 32

def remove_fact(fact)
  @working_memory.remove_fact(fact)
end

#run ⇒ Object 



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# File 'lib/kbs/engine.rb', line 48

def run
  @production_nodes.values.each do |node|
    node.tokens.each do |token|
      node.fire_rule(token)
    end
  end
end

#update(action, fact) ⇒ Object 



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# File 'lib/kbs/engine.rb', line 36

def update(action, fact)
  if action == :add
    @alpha_memories.each do |pattern, memory|
      memory.activate(fact) if fact.matches?(pattern)
    end
  elsif action == :remove
    @alpha_memories.each do |pattern, memory|
      memory.deactivate(fact) if fact.matches?(pattern)
    end
  end
end