Class: Wongi::Engine::NegNode

Inherits:
BetaNode
  • Object
show all
Defined in:
lib/wongi-engine/beta/neg_node.rb

Instance Attribute Summary collapse

Attributes inherited from BetaNode

#children, #context, #parent, #rete

Instance Method Summary collapse

Methods inherited from BetaNode

#assignment_node, #beta_memory, #delete_token, #depth, #empty?, #filter_node, #join_node, #ncc_node, #neg_node, #network, #optional_node, #refresh, #size, #tokens

Methods included from CoreExt

included

Constructor Details

#initialize(parent, tests, alpha, unsafe) ⇒ NegNode

Returns a new instance of NegNode.



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# File 'lib/wongi-engine/beta/neg_node.rb', line 15

def initialize parent, tests, alpha, unsafe
  super(parent)
  @tests, @alpha, @unsafe = tests, alpha, unsafe
  @tokens = []
end

Instance Attribute Details

#alpha ⇒ Object (readonly)

Returns the value of attribute alpha.



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# File 'lib/wongi-engine/beta/neg_node.rb', line 13

def alpha
  @alpha
end

#tests ⇒ Object (readonly)

Returns the value of attribute tests.



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# File 'lib/wongi-engine/beta/neg_node.rb', line 13

def tests
  @tests
end

Instance Method Details

#alpha_activate(wme) ⇒ Object 



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# File 'lib/wongi-engine/beta/neg_node.rb', line 21

def alpha_activate wme
  self.tokens.each do |token|
    if matches?( token, wme ) && ( @unsafe || ! token.generated?( wme ) )# feedback loop protection
      # order matters for proper invalidation
      make_join_result(token, wme)
      #token.delete_children #if token.neg_join_results.empty? # TODO why was this check here? it seems to break things
      children.each do |child|
        child.tokens.each do |t|
          if t.parent == token
            child.beta_deactivate t
            #token.destroy
          end
        end
      end
    end
  end
end

#alpha_deactivate(wme) ⇒ Object 



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# File 'lib/wongi-engine/beta/neg_node.rb', line 39

def alpha_deactivate wme
  wme.neg_join_results.dup.each do |njr|
    safe_tokens.each do |token|
      next unless token == njr.token
      njr.unlink
      if token.neg_join_results.empty?
        children.each do |child|
          child.beta_activate Token.new( child, token, nil, {} )
        end
      end
    end
  end
end

#beta_activate(token) ⇒ Object 



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# File 'lib/wongi-engine/beta/neg_node.rb', line 53

def beta_activate token
  return if @tokens.find { |et| et.duplicate? token }
  @tokens << token
  alpha.wmes.each do |wme|
    if matches?( token, wme )
      make_join_result(token, wme)
    end
  end
  if token.neg_join_results.empty?
    children.each do |child|
      child.beta_activate Token.new( child, token, nil, {} )
    end
  end
end

#beta_deactivate(token) ⇒ Object 



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# File 'lib/wongi-engine/beta/neg_node.rb', line 68

def beta_deactivate token
  return nil unless tokens.find token
  @tokens.delete token
  token.deleted!
  if token.parent
    token.parent.children.delete token # should this go into Token#destroy?
  end
  token.neg_join_results.each &:unlink
  children.each do |child|
    child.tokens.each do |t|
      if t.parent == token
        child.beta_deactivate t
        #token.destroy
      end
    end
  end
  token
end

#refresh_child(child) ⇒ Object 



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# File 'lib/wongi-engine/beta/neg_node.rb', line 87

def refresh_child child
  safe_tokens.each do |token|
    if token.neg_join_results.empty?
      child.beta_activate Token.new( child, token, nil, {} )
    end
  end
  alpha.wmes.each do |wme|
    alpha_activate wme
  end
end