self-challenge-refactoring-code.rb

# Code exercise in refactoring from a code sample from @brianllamar

module DNA
  module Hamming

    def self.compute(pair)
      set_strand_position_by_length(pair) unless pair.same?
      count_the_distance(pair)
    end

    private
    def self.count_the_distance(pair)
      pair.entries.map(&:chars).inject(:zip).select{|a,b| a!=b}.count
    end

    def self.set_strand_position_by_length(pair)
      pair.swap! if pair.inject{|a,b|a.length>b.length}
    end

  end

  class Pair < Struct.new(:first, :second)
    def same?
      inject(:eql?)
    end

    def swap!
      members.zip(entries.reverse) {|a,b| self[a] = b}
    end
  end
end

dna = lambda {|qty| "ACTG".chars.cycle.take(qty).shuffle.join}

pair = DNA::Pair.new(dna[10],dna[12])

puts pair.entries
puts DNA::Hamming.compute(pair)

nice use of the lambda and 👍 for keeping the methods short and to the point.

This is really good, it all makes sense and tells a good story of what the purpose of the code is. The only thing I would change is maybe outdent the word private

private is not a block and therefore indentation doesn't apply. It, by itself, modifies any methods below to private methods. It can also be used inline for just one method private def my_private_method. It's a modifier for methods... you also have public which you can use in the same manner.