Adds Not type class, Fixes sebastiaanvisser#239

src/Clay/Pseudo.hs

@@ -1,9 +1,11 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
 module Clay.Pseudo where
 
 import Data.Text (Text)
 
-import Clay.Render (renderSelector)
+import Clay.Render (renderSelector, renderRefinement)
 import Clay.Selector
 
 import qualified Data.Text.Lazy as Lazy
@@ -64,5 +66,19 @@ nthLastChild  n = func "nth-last-child"   [n]
 nthLastOfType n = func "nth-last-of-type" [n]
 nthOfType     n = func "nth-of-type"      [n]
 
-not :: Selector -> Refinement
-not r = func "not" [Lazy.toStrict (renderSelector r)]
+-- | The 'not' pseudo selector can be applied to both a 'Refinement'
+--
+-- > input # not checked
+-- 
+-- or a 'Selector'
+--
+-- > not p
+
+class Not a where
+  not :: a -> Refinement
+
+instance Not Selector where
+  not r = func "not" [Lazy.toStrict (renderSelector r)]
+
+instance Not Refinement where
+  not r = func "not" (Lazy.toStrict <$> renderRefinement r)

src/Clay/Render.hs

@@ -8,6 +8,7 @@ module Clay.Render
 , putCss
 , renderWith
 , renderSelector
+, renderRefinement
 , withBanner
 )
 where
@@ -120,6 +121,11 @@ renderWith cfg top
 renderSelector :: Selector -> Lazy.Text
 renderSelector = toLazyText . selector compact
 
+-- | Render a CSS `Refinement`.
+
+renderRefinement :: Refinement -> [Lazy.Text]
+renderRefinement r = toLazyText . predicate <$> unFilter r
+
 -------------------------------------------------------------------------------
 
 renderBanner :: Config -> Lazy.Text -> Lazy.Text