Class: IndexedSearch::Match::StartWith

Inherits:
Base
  • Object
show all
Defined in:
lib/indexed_search/match/start_with.rb

Overview

Does a start-with comparison to find words whose beginning part is equal to the given terms. In concept it’s kind of like a nice lowest-common-denominator stemmer for all languages. Though it’s obviously not as good as most real language-specific stemmer algorithms of course.

Note this uses database LIKE matching in some places, and ruby String#start_with? in others, which does not always mean exactly the same thing. But our term normalization in IndexedSearch::Query.split_into_words should make it a non-issue.

Instance Method Summary collapse

Methods inherited from Base

#find, find_attributes, #initialize, match_against_term?, #results, #term_matches, #term_non_matches

Constructor Details

This class inherits a constructor from IndexedSearch::Match::Base

Instance Method Details

#scope ⇒ Object 



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# File 'lib/indexed_search/match/start_with.rb', line 22

def scope
  @scope.where(@scope.arel_table[self.class.matcher_attribute].matches_any(term_matches.collect { |t| "#{t}%" }))
end

#term_map ⇒ Object 



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# File 'lib/indexed_search/match/start_with.rb', line 26

def term_map
  @term_map ||= Hash.new { |hash,key| hash[key] = [] }.tap do |map|
    find.each { |id,count,rank,match| term_matches.each { |term| map[match] << term if match.start_with?(term) } }
  end
end