SemanticVersion.rb

class InvalidSemanticVersionError < StandardError; end

class SemanticVersion

  def initialize(sem_str)
    raise InvalidSemanticVersionError unless _valid_schema? sem_str
    @version_ary = sem_str.split('.').freeze
  end

  def version_ary
    @version_ary
  end

  def version
    @version_ary.join('')
  end

  def compare(right, method)
    right_ary = right.version_ary
    result = false
    @version_ary.
      zip(right_ary).
      each {|l, r| next result = true if l.to_i.send(method, r.to_i) }
    result
  end

  def method_missing(method, *args)
    case method
    when :>, :<, :>=, :<=, :==
      compare args[0], method
    else
      raise NoMethodError
    end
  end

private

  def _valid_schema?(sem_str)
    !!(sem_str =~ /^(\d+\.)*\d+$/)
  end
end