using sass color functions without sass engine

Question

I want to use Sass color functions within a class, without the Sass Engine. I'm already using the sass gem in the project so i thought piggy-backing would be something as easy as:

class Rectangle
  include Sass::Script::Functions
  def color
    Sass::Script::Color.new([0x82, 0x39, 0x06])
  end
  def render
    #haml engine executed with context of self
    #so that within temlate i could call
    #  %stop{offset: '0%', stop: {color: lighten(color)}}
  end
end

UPDATE: see #render above, i want to call lighten(color) from within a haml template rendered within the context of a Rectangle instance

But i get an undefined method assert_type error. The assert_type method is defined within the Sass::Script::Functions::EvaluationContext class. (github file)

Playing around in irb, just to get something close to what i want looks like this:

require 'sass'
eval_context = Sass::Script::Functions::EvaluationContext.new({})
#yes the Sass::Script::Number.new(10) is requried, a simple 10 will not work
color = eval_context.rgb(Sass::Script::Number.new(10), Sass::Script::Number.new(10), Sass::Script::Number.new(10))
eval_context.lighten(color, Sass::Script::Number.new(10))

which is crazy - am i missing something?

Answer 1

Sass::Script::Parser.parse('lighten(#333, 10)', 0, 0).perform(Sass::Environment.new)

Answer 2

Update

Now that I understand your problem better, why not just rewrite the functionality.

require 'sass'

class Rectangle
  include Sass::Script

  def color
    @color ||= Sass::Script::Color.new([0x82, 0x39, 0x06])
  end

  def lighten(ammount)
    hsl = color.hsl.dup
    hsl[2] += ammount
    @color = Sass::Script::Color.new(hue: hsl[0], saturation: hsl[1], lightness: [2])
  end
end

rec = Rectangle.new
rec.lighten(20)

Old Answer

You aren't crazy, you've just included the wrong piece.

This code runs as you expect it. Notice that I removed the ::Functions from the include.

require 'sass'

class Rectangle
  include Sass::Script

  def color
    color = Sass::Script::Color.new([0x82, 0x39, 0x06])
    puts color.class
  end
end

rec = Rectangle.new
rec.color