color_string.rb

class ColorString < String
  ABORT = "\e[0m"
  ESC_SQS = {
    :red         => "\e[1m\e[31m",
    :dark_red    => "\e[31m",
    :green       => "\e[1m\e[32m",
    :dark_green  => "\e[32m",
    :yellow      => "\e[1m\e[33m",
    :dark_yellow => "\e[33m",
    :blue        => "\e[1m\e[34m",
    :dark_blue   => "\e[34m",
    :purple      => "\e[1m\e[35m",
    :bold        => "\e[1m",
    :blink       => "\e[5m"
  }

  def initialize(string='', *effects)
    super(string)
    apply_effects! *effects
  end

  def apply_effects(*effects)
    effects.inject { |eff, memo| decorate ESC_SQS[eff] }
  end

  def apply_effects!(*effects)
    effects.each { |eff| decorate! ESC_SQS[eff] }
    self
  end

  ESC_SQS.each do |key, value|
    define_method(key)       { decorate value }
    define_method("#{key}!") { decorate! value }
  end

  private

  def decorate(str)
    "#{str}#{self}#{ABORT}"
  end

  def decorate!(str)
    insert 0, str
    self << ABORT
  end
end