class Fuzzy

Public Class Methods

find(strings, input) click to toggle source

# File lib/fuzzy_ruby.rb, line 3
def self.find(strings, input)
  # array to store weights of each string
  @weights = Array.new(strings.length, -1)

  # array to store each string
  @strings = strings.dup

  # array to return
  ret = Array.new

  # build regular expression
  regexp = /#{build_regexp(input)}/

  # for each string, calculate weight
  @strings.each_index do |i|
    assign_weights(i, regexp)
  end

  # delete string if there is no match
  @weights.each_index do |i|
    if @weights[i] == -1
      @weights.delete_at(i)
      strings.delete_at(i)
    end
  end

  # return array of strings with best match (least weight)
  @weights.map.with_index.sort_by(&:first).map(&:last).each do |index|
    ret.push strings[index]
  end

  return ret
end

Private Class Methods

assign_weights(index, regexp) click to toggle source

recursive function to assign weight to string once there is match, removes one character from the reg exp and repeat

# File lib/fuzzy_ruby.rb, line 48
def self.assign_weights(index, regexp)
  weight = @strings[index] =~ regexp
  if weight == nil
    return
  end
  @weights[index] += (weight+1)
  if !done(index)
    @strings[index] = @strings[index][weight+1..@strings[index].length]
    assign_weights(index, /#{regexp.source[5..regexp.source.length]}/)
  end
end

build_regexp(string) click to toggle source

build the regular expression

# File lib/fuzzy_ruby.rb, line 38
def self.build_regexp(string)
  regexp = ""
  string.each_char do |c|
    regexp << "(\w*)#{c}"
  end
  regexp << "(\w*)"
end

done(index) click to toggle source

done with string if no more matches

# File lib/fuzzy_ruby.rb, line 61
def self.done(index)
  @strings[index] == nil || @weights[index] == -1 ? true : false
end