Class: Ruleby::Core::JoinNode

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

Overview

This class is a two-input node that is used to create a cross-product of the two network branches above it. It keeps a memory of the left and right inputs and compares new facts to each. These nodes make up what is called the Beta network.

Direct Known Subclasses

NotNode

Instance Attribute Summary collapse

Attributes inherited from ParentNode

#child_nodes

Attributes inherited from Printable

#parent_nodes

Instance Method Summary collapse

Methods inherited from ParentNode

#add_out_node, #assert, #forks?, #propagate_assert, #propagate_retract, #retract

Methods inherited from Node

#resolve

Methods inherited from Printable

#print

Constructor Details

#initialize ⇒ JoinNode

Returns a new instance of JoinNode.



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# File 'lib/core/nodes.rb', line 542

def initialize
  super
  @left_memory = {}
  @right_memory = {} 
  @ref_nodes = []
end

Instance Attribute Details

#ref_nodes ⇒ Object

Returns the value of attribute ref_nodes.



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# File 'lib/core/nodes.rb', line 540

def ref_nodes
  @ref_nodes
end

Instance Method Details

#assert_left(context) ⇒ Object 



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# File 'lib/core/nodes.rb', line 559

def assert_left(context)
  add_to_left_memory(context)
  @right_memory.values.each do |right_context|
    mr = match_ref_nodes(context,right_context)      
    if (mr.is_match)
      new_context = MatchContext.new context.fact, mr  
      propagate_assert(new_context)
    end
  end
end

#assert_right(context) ⇒ Object 



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# File 'lib/core/nodes.rb', line 570

def assert_right(context)
  @right_memory[context.fact.id] = context
  @left_memory.values.flatten.each do |left_context|
    mr = match_ref_nodes(left_context,context)      
    if (mr.is_match)
      new_context = MatchContext.new context.fact, mr                
      propagate_assert(new_context)
    end
  end
end

#retract_left(fact) ⇒ Object 



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# File 'lib/core/nodes.rb', line 549

def retract_left(fact)
  @left_memory.delete(fact.id)
  propagate_retract(fact)
end

#retract_right(fact) ⇒ Object 



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# File 'lib/core/nodes.rb', line 554

def retract_right(fact)
  @right_memory.delete(fact.id)
  propagate_retract(fact)
end

#to_s ⇒ Object 



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# File 'lib/core/nodes.rb', line 581

def to_s
  return "#{self.class}:#{object_id} | #{@left_memory.values} | #{@right_memory}"
end