Class: OMF::Rete::ResultTupleStream

Inherits:
AbstractTupleStream show all
Defined in:
lib/omf_rete/tuple_stream.rb

Overview

A result tuple stream calls the associated processing block for every incoming tuple.

TODO: This should really be a subclass of ProcessingTupleStream, but we have supress_duplicates in this class which may be useful for ProcessingTupleStream as well.

Instance Attribute Summary

Attributes inherited from AbstractTupleStream

#description, #source

Instance Method Summary collapse

Methods inherited from AbstractTupleStream

#describe, #detach, #index_for_binding

Constructor Details

#initialize(description, supress_duplicates = true, &block) ⇒ ResultTupleStream

Returns a new instance of ResultTupleStream.



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# File 'lib/omf_rete/tuple_stream.rb', line 149

def initialize(description, supress_duplicates = true, &block)
  super description
  @block = block
  if supress_duplicates
    @results = Set.new
  end
end

Instance Method Details

#addTuple(tuple) ⇒ Object 



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# File 'lib/omf_rete/tuple_stream.rb', line 170

def addTuple(tuple)
  if @result_map
    ta = @result_map.collect do |i| tuple[i] end
  else
    ta = tuple
  end
  rtuple = Tuple.new(ta, @description)
  if @results
    if @results.add?(ta)
      @block.arity == 1 ? @block.call(rtuple) : @block.call(rtuple, :add)
    end
  else
    @block.arity == 1 ? @block.call(rtuple) : @block.call(rtuple, :add)
  end
end

#check_for_tuple(tuple) ⇒ Object

Return true if tuple can be produced by this stream. A ResultStream only narrows a stream, so we need to potentially expand it (with nil) and pass it up to the source of this stream.



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# File 'lib/omf_rete/tuple_stream.rb', line 209

def check_for_tuple(tuple)
  if @sourcce
    # should check if +tuple+ has the same size as description
    if @result_map
      # need to expand
      unless @expand_map
        @expand_map = @source.description.collect do |name|
          index = @description.find_index do |n2| name == n2 end
        end
      end
      up_tuple = @expand_map.collect do |i| i nil? ? nil : tuple[i] end
    else
      up_tuple = tuple
    end
    @source.check_for_tuple(up_tuple)
  end
end

#clear ⇒ Object 



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# File 'lib/omf_rete/tuple_stream.rb', line 199

def clear()
  @results.clear if @results
  @block.call(nil, :cleared) if @block.arity == 2
end

#removeTuple(tuple) ⇒ Object 



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# File 'lib/omf_rete/tuple_stream.rb', line 186

def removeTuple(tuple)
  if @result_map
    ta = @result_map.collect do |i| tuple[i] end
  else
    ta = tuple
  end
  rtuple = Tuple.new(ta, @description)
  if @results
    @results.delete(ta)
  end
  @block.arity == 1 ? @block.call(rtuple) : @block.call(rtuple, :remove)
end

#source=(source) ⇒ Object 



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# File 'lib/omf_rete/tuple_stream.rb', line 157

def source=(source)
  @source = source
  if @source.description != @description
    @result_map = @description.collect do |name|
      index = @source.description.find_index do |n2| name == n2 end
      if index.nil?
        raise "Unknown selector '#{name}'"
      end
      index
    end
  end
end