You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: levenshtein.rb
    path of file: ./repos/ruby/lib/did_you_mean
    
    the code of the file until where you have to start completion: module DidYouMean
  module Levenshtein # :nodoc:
    # This code is based directly on the Text gem implementation
    # Copyr
    
    def distance(str1, str2)
      n = str1.length
      m = str2.length
      return m if n.zero?
      return n if m.zero?

      d = (0..m).to_a
      x = nil

      # to avoid duplicating an enumerable object, create it outside of the loop
      str2_codepoints = str2.codepoints

      str1.each_codepoint.with_index(1) do |char1, i|
        j = 0
        while j < m
          cost = (char1 == str2_codepoints[j]) ? 0 : 1
          x = min3(
            d[j+1] + 1, # insertion
            i + 1,      # deletion
            d[j] + cost # substitution
          )
          d[j] = i
          i = x

          j += 1
        end
        d[m] = x
      end