haml--haml/lib/sass/script/color.rb

require 'sass/script/literal'

module Sass::Script
  class Color < Literal # :nodoc:

    HTML4_COLORS = {
      'black'   => 0x000000,
      'silver'  => 0xc0c0c0,
      'gray'    => 0x808080,
      'white'   => 0xffffff,
      'maroon'  => 0x800000,
      'red'     => 0xff0000,
      'purple'  => 0x800080,
      'fuchsia' => 0xff00ff,
      'green'   => 0x008000,
      'lime'    => 0x00ff00,
      'olive'   => 0x808000,
      'yellow'  => 0xffff00,
      'navy'    => 0x000080,
      'blue'    => 0x0000ff,
      'teal'    => 0x008080,
      'aqua'    => 0x00ffff
    }

    def initialize(rgb)
      super(rgb.map {|c| c.to_i})
    end

    def plus(other)
      if other.is_a? Sass::Script::String
        Sass::Script::String.new(self.to_s + other.to_s)
      else
        piecewise(other, :+)
      end
    end

    def minus(other)
      if other.is_a? Sass::Script::String
        raise NoMethodError.new(nil, :minus)
      else
        piecewise(other, :-)
      end
    end

    def times(other)
      if other.is_a? Sass::Script::String
        raise NoMethodError.new(nil, :times)
      else
        piecewise(other, :*)
      end
    end

    def div(other)
      if other.is_a? Sass::Script::String
        raise NoMethodError.new(nil, :div)
      else
        piecewise(other, :/)
      end
    end

    def mod(other)
      if other.is_a? Sass::Script::String
        raise NoMethodError.new(nil, :mod)
      else
        piecewise(other, :%)
      end
    end

    def to_s
      red, green, blue = @value.map { |num| num.to_s(16).rjust(2, '0') }
      "##{red}#{green}#{blue}"
    end
    alias_method :inspect, :to_s

    private

    def piecewise(other, operation)
      other_num = other.is_a? Number
      other_val = other.value
      if other_num && !other.unitless?
        raise Sass::SyntaxError.new("Cannot add a number with units (#{other}) to a color (#{self}).") 
      end

      rgb = []
      for i in (0...3)
        res = @value[i].send(operation, other_num ? other_val : other_val[i])
        rgb[i] = [ [res, 255].min, 0 ].max
      end
      Color.new(rgb)
    end
  end
end