# File lib/sass/script/functions.rb, line 898 def alpha(*args) if args.all? do |a| a.is_a?(Sass::Script::Value::String) && a.type == :identifier && a.value =~ /^[a-zA-Z]+\s*=/ end # Support the proprietary MS alpha() function return identifier("alpha(#{args.map {|a| a.to_s}.join(', ')})") end raise ArgumentError.new("wrong number of arguments (#{args.size} for 1)") if args.size != 1 assert_type args.first, :Color, :color number(args.first.alpha) end