Class: KBS::NegationNode

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(alpha_memory, beta_memory, tests = []) ⇒ NegationNode

Returns a new instance of NegationNode.



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

def initialize(alpha_memory, beta_memory, tests = [])
  @alpha_memory = alpha_memory
  @beta_memory = beta_memory
  @successors = []
  @tests = tests
  @tokens_with_matches = Hash.new { |h, k| h[k] = [] }

  alpha_memory.successors << self if alpha_memory
  beta_memory.successors << self if beta_memory
end

Instance Attribute Details

#alpha_memory ⇒ Object

Returns the value of attribute alpha_memory.



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

def alpha_memory
  @alpha_memory
end

#beta_memory ⇒ Object

Returns the value of attribute beta_memory.



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

def beta_memory
  @beta_memory
end

#successors ⇒ Object

Returns the value of attribute successors.



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

def successors
  @successors
end

#tests ⇒ Object

Returns the value of attribute tests.



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

def tests
  @tests
end

Instance Method Details

#left_activate(token) ⇒ Object 



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# File 'lib/kbs/negation_node.rb', line 18

def left_activate(token)
  matches = @alpha_memory.items.select { |fact| perform_join_tests(token, fact) }

  if matches.empty?
    new_token = Token.new(token, nil, self)
    token.children << new_token
    @successors.each { |s| s.activate(new_token) }
  else
    @tokens_with_matches[token] = matches
  end
end

#right_activate(fact) ⇒ Object 



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# File 'lib/kbs/negation_node.rb', line 30

def right_activate(fact)
  @beta_memory.tokens.each do |token|
    if perform_join_tests(token, fact)
      if @tokens_with_matches[token].empty?
        token.children.each do |child|
          @successors.each { |s| s.deactivate(child) if s.respond_to?(:deactivate) }
        end
        token.children.clear
      end
      @tokens_with_matches[token] << fact
    end
  end
end

#right_deactivate(fact) ⇒ Object 



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# File 'lib/kbs/negation_node.rb', line 44

def right_deactivate(fact)
  @beta_memory.tokens.each do |token|
    if @tokens_with_matches[token].include?(fact)
      @tokens_with_matches[token].delete(fact)

      if @tokens_with_matches[token].empty?
        new_token = Token.new(token, nil, self)
        token.children << new_token
        @successors.each { |s| s.activate(new_token) }
      end
    end
  end
end