Module: OKF::Bundle::Search::Scan

Defined in:
lib/okf/bundle/search/scan.rb

Overview

The linear engine: terms matched against raw field text, one document at a time. No index, so nothing is tokenized and nothing is normalized — a phrase stays a phrase, 7.2.0 stays one string, and an infix matches. That is the exactness a token index gives up, and the reason this engine survived the swap.

Two readings of a term, and the engine is the raw text half of the split rather than the regexp half:

`regexp: false` — literal substring, which is what this engine did
                before the index landed, and what `--engine scan`
                restores. Terms are escaped, so `7.2.0` does not
                match `7x2y0` and `[draft]` is not a character class.
`regexp: true`  — the term is a pattern, opted into with `-e`.

Conflating the two would make choosing the engine silently change what the terms mean, and turn an ordinary term like review (pending into exit 2.

Scoring is the summed weight of the fields that matched: absolute, and so comparable across bundles without a corpus to normalize against.

Constant Summary collapse

CAPABILITIES = 
%i[regexp].freeze

Class Method Summary collapse

Class Method Details

.available? ⇒ Boolean

No backing store to fail: the engine is Regexp and Enumerable.

Returns:

  • (Boolean) 


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# File 'lib/okf/bundle/search/scan.rb', line 41

def available?
  true
end

.call(documents, terms, fields:, regexp: false, **_options) ⇒ Object

Raises RegexpError on an invalid pattern under regexp: true — the caller owns turning that into a usage error. A literal term cannot raise, because it is escaped before it is compiled. The hit's terms are the compiled patterns, which is what the facade points its snippet window at.



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# File 'lib/okf/bundle/search/scan.rb', line 50

def call(documents, terms, fields:, regexp: false, **_options)
  patterns = terms.map do |term|
    Regexp.new(regexp ? term : Regexp.escape(term), Regexp::IGNORECASE)
  end

  hits = []
  documents.each do |document|
    matched = matched_fields(document, patterns, fields)
    next if matched.nil?

    hits << {
      key: document["key"],
      matched: matched,
      score: matched.map { |field| WEIGHTS[field] }.reduce(0, :+),
      terms: patterns
    }
  end
  hits
end

.capabilities ⇒ Object 



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# File 'lib/okf/bundle/search/scan.rb', line 36

def capabilities
  CAPABILITIES
end

.id ⇒ Object 



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# File 'lib/okf/bundle/search/scan.rb', line 32

def id
  :scan
end