Class: Ruleby::Core::RootNode

Inherits:
Object
  • Object
show all
Defined in:
lib/core/nodes.rb

Overview

This class acts as the root-node of the network. It contains the logic for building the node-network from a set of rules, and updating it according to the working memory

Instance Method Summary collapse

Constructor Details

#initialize(working_memory) ⇒ RootNode

Returns a new instance of RootNode.



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# File 'lib/core/nodes.rb', line 19

def initialize(working_memory)
  @working_memory = working_memory
  @type_node = nil
  @inherit_nodes = []
  @atom_nodes = [] 
  @join_nodes = []
  @terminal_nodes = []
end

Instance Method Details

#assert_fact(fact) ⇒ Object

When a new fact is added to working memory, or an existing one is removed this method is called. It finds any nodes that depend on it, and updates them accordingly.



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# File 'lib/core/nodes.rb', line 39

def assert_fact(fact) 
  @type_node and fact.token == :plus ? @type_node.assert(fact) : @type_node.retract(fact) 
  @inherit_nodes.each do |node|
    fact.token == :plus ? node.assert(fact) : node.retract(fact) 
  end
end

#assert_rule(rule) ⇒ Object

This method is invoked when a new rule is added to the system. The rule is processed and the appropriate nodes are added to the network.



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# File 'lib/core/nodes.rb', line 30

def assert_rule(rule)
  terminal_node = TerminalNode.new rule  
  build_network(rule.pattern, terminal_node)             
  @terminal_nodes.push terminal_node
end

#child_nodes ⇒ Object 



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# File 'lib/core/nodes.rb', line 83

def child_nodes
  return @inherit_nodes + [@type_node]
end

#increment_counter ⇒ Object

Increments the activation counter. This is just a pass-thru to the static variable in the terminal node



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# File 'lib/core/nodes.rb', line 48

def increment_counter
  TerminalNode.increment_counter
end

#matches(initial = true) ⇒ Object

When invoked, this method returns a list of all Action|MatchContext pairs as Activations. The list is generated when facts and rules are asserted, so no comparisions are done here (i.e. no Backward Chaining).



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# File 'lib/core/nodes.rb', line 61

def matches(initial=true)
  agenda = Array.new
  @terminal_nodes.each do |node|
    node.activations.values.each do |a|
      if initial
        a.used = false 
        agenda.push a 
      elsif !a.used
        agenda.push a 
      end          
    end 
  end
  return agenda
end

#print ⇒ Object 



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# File 'lib/core/nodes.rb', line 76

def print
  puts 'NETWORK:'    
  @terminal_nodes.each do |n|
    n.print(' ')
  end
end

#reset_counter ⇒ Object

Resets the activation counter. This is just a pass-thru to the static variable in the terminal node



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# File 'lib/core/nodes.rb', line 54

def reset_counter
  TerminalNode.reset_counter
end