Document declarations in Categorizable.hs

src/Categorizable.hs

@@ -5,12 +5,14 @@ import Term
 import Control.Comonad.Cofree
 import Data.Set
 
+-- | The class of types that have categories.
 class Categorizable a where
   categories :: a -> Set String
 
 instance Categorizable annotation => Categorizable (Term a annotation) where
   categories (annotation :< _) = categories annotation
 
+-- | Test whether the categories from the categorizables intersect.
 comparable :: Categorizable a => a -> a -> Bool
 comparable a b = catsA == catsB || (not . Data.Set.null $ intersection catsA catsB)
   where