class method self.levenshtein_distance

Ruby on Rails 4.2.9

Since v4.2.9 Last seen in v4.2.9

Signature

self.levenshtein_distance(str1, str2)

This code is based directly on the Text gem implementation Returns a value representing the “cost” of transforming str1 into str2

Parameters

str1 req
str2 req
Source
# File railties/lib/rails/generators.rb, line 258
      def self.levenshtein_distance str1, str2
        s = str1
        t = str2
        n = s.length
        m = t.length

        return m if (0 == n)
        return n if (0 == m)

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

        str1.each_char.each_with_index do |char1,i|
          e = i+1

          str2.each_char.each_with_index do |char2,j|
            cost = (char1 == char2) ? 0 : 1
            x = [
                 d[j+1] + 1, # insertion
                 e + 1,      # deletion
                 d[j] + cost # substitution
                ].min
            d[j] = e
            e = x
          end

          d[m] = x
        end

        return x
      end

Defined in railties/lib/rails/generators.rb line 258 · View on GitHub · Improve this page · Find usages on GitHub

Defined in Rails::Generators

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