Module: String::LiquidMetal

Defined in:
lib/string_scorer/scorers/liquidmetal.rb

Overview

Algorithm from github.com/rmm5t/liquidmetal/blob/master/liquidmetal.js

Constant Summary collapse

SCORE_NO_MATCH = 
0.0
SCORE_MATCH = 
1.0
SCORE_TRAILING = 
0.8
SCORE_TRAILING_BUT_STARTED = 
0.9
SCORE_BUFFER = 
0.85

Class Method Summary collapse

Class Method Details

.fill_array(array, value, from = 0, to = array.size) ⇒ Object 



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# File 'lib/string_scorer/scorers/liquidmetal.rb', line 66

def fill_array(array, value, from=0, to=array.size)
  from = 0 if from < 0
  to   = 0 if to   < 0
  size = 1 + (to - from)

  array[from..to] = Array.new(size, value)
  array
end

.new_word?(string, index) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/string_scorer/scorers/liquidmetal.rb', line 56

def new_word?(string, index)
  c = string[index - 1]
  (index == 0 || c==32 || c == 9)
end

.score(string, abbreviation) ⇒ Object 



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# File 'lib/string_scorer/scorers/liquidmetal.rb', line 15

def score(string, abbreviation)
  # Short circuits
  return SCORE_TRAILING if abbreviation.length == 0
  return SCORE_NO_MATCH if abbreviation.length > string.length
  return SCORE_MATCH    if abbreviation == string

  scores = score_array(string, abbreviation);
  scores.inject(0) {|v,m| v + m} / scores.size
end

.score_array(string, abbreviation) ⇒ Object 



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# File 'lib/string_scorer/scorers/liquidmetal.rb', line 25

def score_array(string, abbreviation)
  scores = Array.new(string.length)
  lower  = string.downcase
  chars  = abbreviation.downcase.split("")

  last_index = -1
  started    = false
  chars.each do |c|
    index = lower.index(c, last_index + 1)

    return fill_array(scores, SCORE_NO_MATCH) if index.nil?
    started = true if index == 0

    if new_word?(string, index)
      scores[index-1] = 1;
      fill_array(scores, SCORE_BUFFER, last_index + 1, index - 1)
    elsif uppercase?(string, index)
      fill_array(scores, SCORE_BUFFER, last_index + 1, index)
    else
      fill_array(scores, SCORE_NO_MATCH, last_index + 1, index)
    end

    scores[index] = SCORE_MATCH
    last_index = index
  end

  trailing_score = (started ? SCORE_TRAILING_BUT_STARTED : SCORE_TRAILING)
  fill_array(scores, trailing_score, last_index + 1)
  scores
end

.uppercase?(string, index) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/string_scorer/scorers/liquidmetal.rb', line 61

def uppercase?(string, index)
  c = string[index]
  (65..90).include?(c)
end