remove MonadWriter functions from Writer.CPS module

libs/base/Control/Monad/Writer/CPS.idr

@@ -105,48 +105,3 @@ MonadTrans (WriterT w) where
 public export %inline
 HasIO m => HasIO (WriterT w m) where
   liftIO = lift . liftIO
-
---------------------------------------------------------------------------------
---          Writer Operations
---------------------------------------------------------------------------------
-
-||| Construct a writer computation from a (result, output) pair.
-public export %inline
-writer : (Semigroup w, Applicative m) => (a, w) -> WriterT w m a
-writer = writerT . pure
-
-||| `tell w` is an action that produces the output `w`.
-public export %inline
-tell : (Semigroup w, Applicative m) => w -> WriterT w m ()
-tell w' = writer ((), w')
-
-||| `listens f m` is an action that executes the action `m` and adds
-||| the result of applying `f` to the output to the value of the computation.
-public export %inline
-listens :  (Monoid w, Functor m)
-        => (w -> b) -> WriterT w m a -> WriterT w m (a, b)
-listens f m = MkWriterT \w =>
-                (\(a,w') => ((a,f w'),w <+> w')) <$> runWriterT m
-
-||| `listen m` is an action that executes the action `m` and adds its
-||| output to the value of the computation.
-public export %inline
-listen :  (Monoid w, Functor m) => WriterT w m a -> WriterT w m (a, w)
-listen = listens id
-
-||| `pass m` is an action that executes the action `m`, which returns
-||| a value and a function, and returns the value, applying the function
-||| to the output.
-public export %inline
-pass : (Monoid w, Semigroup w', Functor m)
-     => WriterT w m (a, w -> w') -> WriterT w' m a
-pass m = MkWriterT \w =>
-           (\((a,f),w') => (a,w <+> f w')) <$> runWriterT m
-
-||| `censor f m` is an action that executes the action `m` and
-||| applies the function `f` to its output, leaving the return value
-||| unchanged.
-public export %inline
-censor : (Monoid w, Functor m) => (w -> w) -> WriterT w m a -> WriterT w m a
-censor f m = MkWriterT \w =>
-               (\(a,w') => (a,w <+> f w')) <$> runWriterT m

libs/base/Control/Monad/Writer/Interface.idr

@@ -41,23 +41,30 @@ interface (Monoid w, Monad m) => MonadWriter w m | m where
 ||| the result of applying @f@ to the output to the value of the computation.
 public export
 listens : MonadWriter w m => (w -> b) -> m a -> m (a, b)
-listens f m = do (a, w) <- listen m
-                 pure (a, f w)
+listens f = map (\(a,w) => (a,f w)) . listen
 
 ||| `censor f m` is an action that executes the action `m` and
 ||| applies the function `f` to its output, leaving the return value
 ||| unchanged.
 public export
 censor : MonadWriter w m => (w -> w) -> m a -> m a
-censor f m = pass $ do a <- m
-                       pure (a, f)
+censor f = pass . map (\a => (a,f))
+
+--------------------------------------------------------------------------------
+--          Implementations
+--------------------------------------------------------------------------------
 
 public export %inline
 (Monoid w, Monad m) => MonadWriter w (WriterT w m) where
-  writer = Writer.writer
-  tell   = Writer.tell
-  listen = Writer.listen
-  pass   = Writer.pass
+  writer   = writerT . pure
+
+  listen m = MkWriterT \w =>
+               (\(a,w') => ((a,w'),w <+> w')) <$> runWriterT m
+
+  tell w'  = writer ((), w')
+
+  pass m   = MkWriterT \w =>
+               (\((a,f),w') => (a,w <+> f w')) <$> runWriterT m
 
 public export %inline
 (Monoid w, Monad m) => MonadWriter w (RWST r w s m) where