Add a new helper function to reject values from a list.

lib/compass/sass_extensions/functions/lists.rb

@@ -76,7 +76,7 @@ module Compass::SassExtensions::Functions::Lists
 
   # removes the given values from the list.
   def reject(list, *values)
-    Sass::Script::List.new(list.values.reject{|v| values.any?{|o| v == o}}, list.separator)
+    Sass::Script::List.new(list.value.reject{|v| values.any?{|o| v == o}}, list.separator)
   end
 
   # returns the first value of a space delimited list.

test/units/sass_extensions_test.rb

@@ -95,6 +95,11 @@ class SassExtensionsTest < Test::Unit::TestCase
     assert_equal "true", evaluate("prefixed(-css2, css2-fallback(css3, css2))")
   end
 
+  def test_reject
+    assert_equal "b d", evaluate("reject(a b c d, a, c)")
+    assert_equal "a b c d", evaluate("reject(a b c d, e)")
+  end
+
 protected
   def evaluate(value)
     Sass::Script::Parser.parse(value, 0, 0).perform(Sass::Environment.new).to_s