Class: Ferret::Search::ReqOptSumScorer

Inherits:
Scorer
  • Object
show all
Defined in:
lib/ferret/search/req_opt_sum_scorer.rb

Overview

A Scorer for queries with a required part and an optional part. Delays skip_to() on the optional part until a score() is needed.

This Scorer implements Scorer#skip_to(int).

Constant Summary

Constants inherited from Scorer

Scorer::MAX_DOCS

Instance Attribute Summary

Attributes inherited from Scorer

#similarity

Instance Method Summary collapse

Methods inherited from Scorer

#each_hit, #each_hit_up_to

Constructor Details

#initialize(req_scorer, opt_scorer) ⇒ ReqOptSumScorer

The scorers passed from the constructor. These are set to nil as soon as their next? or skip_to() returns false.

Construct a ReqOptScorer.

req_scorer

The required scorer. This must match.

opt_scorer

The optional scorer. This is used for scoring only.



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# File 'lib/ferret/search/req_opt_sum_scorer.rb', line 13

def initialize(req_scorer, opt_scorer)
  super(nil) # No similarity used.
  @req_scorer = req_scorer
  @opt_scorer = opt_scorer

  @first_time_opt_scorer = true
end

Instance Method Details

#doc ⇒ Object 



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# File 'lib/ferret/search/req_opt_sum_scorer.rb', line 30

def doc() 
  return @req_scorer.doc()
end

#explain(doc) ⇒ Object

TODO:

Also show the total score.

Explain the score of a document. See BooleanScorer.explain() on how to do this.



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# File 'lib/ferret/search/req_opt_sum_scorer.rb', line 62

def explain(doc)
  e = Explanation.new()
  e.description = "required, optional"
  e.details << @req_scorer.explain(doc)
  e.details << @opt_scorer.explain(doc)
  return e
end

#next? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ferret/search/req_opt_sum_scorer.rb', line 22

def next?
  return @req_scorer.next?
end

#score ⇒ Object

Returns the score of the current document matching the query. Initially invalid, until #next? is called the first time.

returns

The score of the required scorer, eventually increased by the score of the optional scorer when it also matches the current document.



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# File 'lib/ferret/search/req_opt_sum_scorer.rb', line 40

def score()
  cur_doc = @req_scorer.doc
  req_score = @req_scorer.score
  if @first_time_opt_scorer
    @first_time_opt_scorer = false
    if not @opt_scorer.skip_to(cur_doc) 
      @opt_scorer = nil
      return req_score
    end
  elsif @opt_scorer.nil?
    return req_score
  elsif @opt_scorer.doc < cur_doc and not @opt_scorer.skip_to(cur_doc)
    @opt_scorer = nil
    return req_score
  end
  # assert (@opt_scorer != nil) and (@opt_scorer.doc() >= cur_doc)
  return (@opt_scorer.doc == cur_doc) ? req_score + @opt_scorer.score() : req_score
end

#skip_to(target) ⇒ Object 



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# File 'lib/ferret/search/req_opt_sum_scorer.rb', line 26

def skip_to(target)
  return @req_scorer.skip_to(target)
end