deb_compare.rb

def deb_compare(left, right)
    mine = left.scan(/\d+|[^\d]+/)
    theirs = right.scan(/\d+|[^\d]+/)

    lhs = mine.shift
    rhs = theirs.shift

    while lhs
      if rhs.nil?
        if lhs == '~'
          return 1
        end
        return -1
      end

      if lhs =~ /[^\d]+/ && rhs =~ /[^\d]+/
        if lhs.length >= rhs.length
          lhs.scan(/./).zip(rhs.scan(/./)).each do |chars|
            lc, rc = order(chars.first), order(chars.last)
            if lc != rc
              return lc <=> rc
            end
          end
        else
          rhs.scan(/./).zip(lhs.scan(/./)).each do |chars|
            rc, lc = order(chars.first), order(chars.last)
            if lc != rc
              return lc <=> rc
            end
          end
        end
      end

      if lhs =~ /\d+/ && rhs =~ /\d+/
        if lhs != rhs
          return lhs.to_i <=> rhs.to_i
        end
      elsif lhs =~ /\d+/
        return -1
      elsif rhs =~ /\d+/
        return 1
      end

      lhs = mine.shift
      rhs = theirs.shift
    end

    # other is longer
    if rhs
      last = left.scan(/\d+|[^\d]+/)
      if last == '~'
        return -1
      end
      return 1
    end

    return 0
  end