string similarity metrics in ruby

hamming_distance.rb

# http://staffwww.dcs.shef.ac.uk/people/S.Chapman/stringmetrics.html#hamming

def hamming_distance(str1, str2)
  str1.split(//).zip(str2.split(//)).inject(0) { |h, e| e[0]==e[1] ? h+0 : h+1 }
end

string_similarity_metrics.md

source: http://staffwww.dcs.shef.ac.uk/people/S.Chapman/stringmetrics.html currently implemented:

• hamming distance.

Nice. But odd that these are instance methods that take two args. Shouldn't they be class methods that take two args, or instance methods that take one arg?

@Mori agreed. For those who don't want to invade String class here is my adaptation + usage https://gist.github.com/hakunin/5568313

@dingsdax Thanks for sharing the two implementations, helped me a lot!