Class: TuiTui::Fuzzy

Inherits:
Object
  • Object
show all
Defined in:
lib/tui_tui/fuzzy.rb

Overview

Query-prepared subsequence matcher used to rank many candidates consistently.

Defined Under Namespace

Classes: Match

Constant Summary collapse

BOUNDARY = 
"/\\_-. ".freeze

Instance Method Summary collapse

Constructor Details

#initialize(query) ⇒ Fuzzy

Returns a new instance of Fuzzy.



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# File 'lib/tui_tui/fuzzy.rb', line 10

def initialize(query)
  @query = query.to_s.downcase.grapheme_clusters
end

Instance Method Details

#match(string) ⇒ Object 



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# File 'lib/tui_tui/fuzzy.rb', line 14

def match(string)
  return Match.new(score: 0, positions: []) if @query.empty?

  haystack = string.downcase.grapheme_clusters
  positions = []
  from = 0
  @query.each do |grapheme|
    at = (from...haystack.size).find { |i| haystack[i] == grapheme } or return nil

    positions << at
    from = at + 1
  end

  Match.new(score: score(haystack, positions), positions: positions)
end

#rank(candidates) ⇒ Object 



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# File 'lib/tui_tui/fuzzy.rb', line 30

def rank(candidates)
  candidates
    .filter_map do |item|
      found = match(block_given? ? yield(item) : item)
      [item, found] if found
    end
    .sort_by { |(_item, found)| -found.score }
end