chore: Remove remaining Bazel-related files r/31

37 files changed, 0 insertions, 7695 deletions

diff --git a/third_party/bazel/rules_haskell/examples/transformers/BUILD.bazel b/third_party/bazel/rules_haskell/examples/transformers/BUILD.bazel
deleted file mode 100644
index 092111f9f19a..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/BUILD.bazel
+++ /dev/null
@@ -1,19 +0,0 @@
-load(
-    "@io_tweag_rules_haskell//haskell:haskell.bzl",
-    "haskell_cc_import",
-    "haskell_library",
-    "haskell_toolchain_library",
-)
-
-haskell_toolchain_library(name = "base")
-
-haskell_library(
-    name = "transformers",
-    srcs = glob([
-        "Data/**/*.hs",
-        "Control/**/*.hs",
-    ]),
-    version = "0",
-    visibility = ["//visibility:public"],
-    deps = [":base"],
-)
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Applicative/Backwards.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Applicative/Backwards.hs
deleted file mode 100644
index 7ed74acbace0..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Applicative/Backwards.hs
+++ /dev/null
@@ -1,112 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Applicative.Backwards
--- Copyright   :  (c) Russell O'Connor 2009
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Making functors with an 'Applicative' instance that performs actions
--- in the reverse order.
------------------------------------------------------------------------------
-
-module Control.Applicative.Backwards (
-    Backwards(..),
-  ) where
-
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-
-import Prelude hiding (foldr, foldr1, foldl, foldl1, null, length)
-import Control.Applicative
-import Data.Foldable
-import Data.Traversable
-
--- | The same functor, but with an 'Applicative' instance that performs
--- actions in the reverse order.
-newtype Backwards f a = Backwards { forwards :: f a }
-
-instance (Eq1 f) => Eq1 (Backwards f) where
-    liftEq eq (Backwards x) (Backwards y) = liftEq eq x y
-    {-# INLINE liftEq #-}
-
-instance (Ord1 f) => Ord1 (Backwards f) where
-    liftCompare comp (Backwards x) (Backwards y) = liftCompare comp x y
-    {-# INLINE liftCompare #-}
-
-instance (Read1 f) => Read1 (Backwards f) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp rl) "Backwards" Backwards
-
-instance (Show1 f) => Show1 (Backwards f) where
-    liftShowsPrec sp sl d (Backwards x) =
-        showsUnaryWith (liftShowsPrec sp sl) "Backwards" d x
-
-instance (Eq1 f, Eq a) => Eq (Backwards f a) where (==) = eq1
-instance (Ord1 f, Ord a) => Ord (Backwards f a) where compare = compare1
-instance (Read1 f, Read a) => Read (Backwards f a) where readsPrec = readsPrec1
-instance (Show1 f, Show a) => Show (Backwards f a) where showsPrec = showsPrec1
-
--- | Derived instance.
-instance (Functor f) => Functor (Backwards f) where
-    fmap f (Backwards a) = Backwards (fmap f a)
-    {-# INLINE fmap #-}
-
--- | Apply @f@-actions in the reverse order.
-instance (Applicative f) => Applicative (Backwards f) where
-    pure a = Backwards (pure a)
-    {-# INLINE pure #-}
-    Backwards f <*> Backwards a = Backwards (a <**> f)
-    {-# INLINE (<*>) #-}
-
--- | Try alternatives in the same order as @f@.
-instance (Alternative f) => Alternative (Backwards f) where
-    empty = Backwards empty
-    {-# INLINE empty #-}
-    Backwards x <|> Backwards y = Backwards (x <|> y)
-    {-# INLINE (<|>) #-}
-
--- | Derived instance.
-instance (Foldable f) => Foldable (Backwards f) where
-    foldMap f (Backwards t) = foldMap f t
-    {-# INLINE foldMap #-}
-    foldr f z (Backwards t) = foldr f z t
-    {-# INLINE foldr #-}
-    foldl f z (Backwards t) = foldl f z t
-    {-# INLINE foldl #-}
-    foldr1 f (Backwards t) = foldr1 f t
-    {-# INLINE foldr1 #-}
-    foldl1 f (Backwards t) = foldl1 f t
-    {-# INLINE foldl1 #-}
-#if MIN_VERSION_base(4,8,0)
-    null (Backwards t) = null t
-    length (Backwards t) = length t
-#endif
-
--- | Derived instance.
-instance (Traversable f) => Traversable (Backwards f) where
-    traverse f (Backwards t) = fmap Backwards (traverse f t)
-    {-# INLINE traverse #-}
-    sequenceA (Backwards t) = fmap Backwards (sequenceA t)
-    {-# INLINE sequenceA #-}
-
-#if MIN_VERSION_base(4,12,0)
--- | Derived instance.
-instance Contravariant f => Contravariant (Backwards f) where
-    contramap f = Backwards . contramap f . forwards
-    {-# INLINE contramap #-}
-#endif
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Applicative/Lift.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Applicative/Lift.hs
deleted file mode 100644
index 8d35e288c025..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Applicative/Lift.hs
+++ /dev/null
@@ -1,165 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Applicative.Lift
--- Copyright   :  (c) Ross Paterson 2010
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Adding a new kind of pure computation to an applicative functor.
------------------------------------------------------------------------------
-
-module Control.Applicative.Lift (
-    -- * Lifting an applicative
-    Lift(..),
-    unLift,
-    mapLift,
-    elimLift,
-    -- * Collecting errors
-    Errors,
-    runErrors,
-    failure,
-    eitherToErrors
-  ) where
-
-import Data.Functor.Classes
-
-import Control.Applicative
-import Data.Foldable (Foldable(foldMap))
-import Data.Functor.Constant
-import Data.Monoid (Monoid(..))
-import Data.Traversable (Traversable(traverse))
-
--- | Applicative functor formed by adding pure computations to a given
--- applicative functor.
-data Lift f a = Pure a | Other (f a)
-
-instance (Eq1 f) => Eq1 (Lift f) where
-    liftEq eq (Pure x1) (Pure x2) = eq x1 x2
-    liftEq _ (Pure _) (Other _) = False
-    liftEq _ (Other _) (Pure _) = False
-    liftEq eq (Other y1) (Other y2) = liftEq eq y1 y2
-    {-# INLINE liftEq #-}
-
-instance (Ord1 f) => Ord1 (Lift f) where
-    liftCompare comp (Pure x1) (Pure x2) = comp x1 x2
-    liftCompare _ (Pure _) (Other _) = LT
-    liftCompare _ (Other _) (Pure _) = GT
-    liftCompare comp (Other y1) (Other y2) = liftCompare comp y1 y2
-    {-# INLINE liftCompare #-}
-
-instance (Read1 f) => Read1 (Lift f) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith rp "Pure" Pure `mappend`
-        readsUnaryWith (liftReadsPrec rp rl) "Other" Other
-
-instance (Show1 f) => Show1 (Lift f) where
-    liftShowsPrec sp _ d (Pure x) = showsUnaryWith sp "Pure" d x
-    liftShowsPrec sp sl d (Other y) =
-        showsUnaryWith (liftShowsPrec sp sl) "Other" d y
-
-instance (Eq1 f, Eq a) => Eq (Lift f a) where (==) = eq1
-instance (Ord1 f, Ord a) => Ord (Lift f a) where compare = compare1
-instance (Read1 f, Read a) => Read (Lift f a) where readsPrec = readsPrec1
-instance (Show1 f, Show a) => Show (Lift f a) where showsPrec = showsPrec1
-
-instance (Functor f) => Functor (Lift f) where
-    fmap f (Pure x) = Pure (f x)
-    fmap f (Other y) = Other (fmap f y)
-    {-# INLINE fmap #-}
-
-instance (Foldable f) => Foldable (Lift f) where
-    foldMap f (Pure x) = f x
-    foldMap f (Other y) = foldMap f y
-    {-# INLINE foldMap #-}
-
-instance (Traversable f) => Traversable (Lift f) where
-    traverse f (Pure x) = Pure <$> f x
-    traverse f (Other y) = Other <$> traverse f y
-    {-# INLINE traverse #-}
-
--- | A combination is 'Pure' only if both parts are.
-instance (Applicative f) => Applicative (Lift f) where
-    pure = Pure
-    {-# INLINE pure #-}
-    Pure f <*> Pure x = Pure (f x)
-    Pure f <*> Other y = Other (f <$> y)
-    Other f <*> Pure x = Other (($ x) <$> f)
-    Other f <*> Other y = Other (f <*> y)
-    {-# INLINE (<*>) #-}
-
--- | A combination is 'Pure' only either part is.
-instance (Alternative f) => Alternative (Lift f) where
-    empty = Other empty
-    {-# INLINE empty #-}
-    Pure x <|> _ = Pure x
-    Other _ <|> Pure y = Pure y
-    Other x <|> Other y = Other (x <|> y)
-    {-# INLINE (<|>) #-}
-
--- | Projection to the other functor.
-unLift :: (Applicative f) => Lift f a -> f a
-unLift (Pure x) = pure x
-unLift (Other e) = e
-{-# INLINE unLift #-}
-
--- | Apply a transformation to the other computation.
-mapLift :: (f a -> g a) -> Lift f a -> Lift g a
-mapLift _ (Pure x) = Pure x
-mapLift f (Other e) = Other (f e)
-{-# INLINE mapLift #-}
-
--- | Eliminator for 'Lift'.
---
--- * @'elimLift' f g . 'pure' = f@
---
--- * @'elimLift' f g . 'Other' = g@
---
-elimLift :: (a -> r) -> (f a -> r) -> Lift f a -> r
-elimLift f _ (Pure x) = f x
-elimLift _ g (Other e) = g e
-{-# INLINE elimLift #-}
-
--- | An applicative functor that collects a monoid (e.g. lists) of errors.
--- A sequence of computations fails if any of its components do, but
--- unlike monads made with 'ExceptT' from "Control.Monad.Trans.Except",
--- these computations continue after an error, collecting all the errors.
---
--- * @'pure' f '<*>' 'pure' x = 'pure' (f x)@
---
--- * @'pure' f '<*>' 'failure' e = 'failure' e@
---
--- * @'failure' e '<*>' 'pure' x = 'failure' e@
---
--- * @'failure' e1 '<*>' 'failure' e2 = 'failure' (e1 '<>' e2)@
---
-type Errors e = Lift (Constant e)
-
--- | Extractor for computations with accumulating errors.
---
--- * @'runErrors' ('pure' x) = 'Right' x@
---
--- * @'runErrors' ('failure' e) = 'Left' e@
---
-runErrors :: Errors e a -> Either e a
-runErrors (Other (Constant e)) = Left e
-runErrors (Pure x) = Right x
-{-# INLINE runErrors #-}
-
--- | Report an error.
-failure :: e -> Errors e a
-failure e = Other (Constant e)
-{-# INLINE failure #-}
-
--- | Convert from 'Either' to 'Errors' (inverse of 'runErrors').
-eitherToErrors :: Either e a -> Errors e a
-eitherToErrors = either failure Pure
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Signatures.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Signatures.hs
deleted file mode 100644
index ce128ee182e1..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Signatures.hs
+++ /dev/null
@@ -1,56 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Signatures
--- Copyright   :  (c) Ross Paterson 2012
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Signatures for monad operations that require specialized lifting.
--- Each signature has a uniformity property that the lifting should satisfy.
------------------------------------------------------------------------------
-
-module Control.Monad.Signatures (
-    CallCC, Catch, Listen, Pass
-  ) where
-
--- | Signature of the @callCC@ operation,
--- introduced in "Control.Monad.Trans.Cont".
--- Any lifting function @liftCallCC@ should satisfy
---
--- * @'lift' (f k) = f' ('lift' . k) => 'lift' (cf f) = liftCallCC cf f'@
---
-type CallCC m a b = ((a -> m b) -> m a) -> m a
-
--- | Signature of the @catchE@ operation,
--- introduced in "Control.Monad.Trans.Except".
--- Any lifting function @liftCatch@ should satisfy
---
--- * @'lift' (cf m f) = liftCatch ('lift' . cf) ('lift' f)@
---
-type Catch e m a = m a -> (e -> m a) -> m a
-
--- | Signature of the @listen@ operation,
--- introduced in "Control.Monad.Trans.Writer".
--- Any lifting function @liftListen@ should satisfy
---
--- * @'lift' . liftListen = liftListen . 'lift'@
---
-type Listen w m a = m a -> m (a, w)
-
--- | Signature of the @pass@ operation,
--- introduced in "Control.Monad.Trans.Writer".
--- Any lifting function @liftPass@ should satisfy
---
--- * @'lift' . liftPass = liftPass . 'lift'@
---
-type Pass w m a =  m (a, w -> w) -> m a
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Accum.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Accum.hs
deleted file mode 100644
index 0a85c43f62bb..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Accum.hs
+++ /dev/null
@@ -1,292 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Accum
--- Copyright   :  (c) Nickolay Kudasov 2016
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The lazy 'AccumT' monad transformer, which adds accumulation
--- capabilities (such as declarations or document patches) to a given monad.
---
--- This monad transformer provides append-only accumulation
--- during the computation. For more general access, use
--- "Control.Monad.Trans.State" instead.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Accum (
-    -- * The Accum monad
-    Accum,
-    accum,
-    runAccum,
-    execAccum,
-    evalAccum,
-    mapAccum,
-    -- * The AccumT monad transformer
-    AccumT(AccumT),
-    runAccumT,
-    execAccumT,
-    evalAccumT,
-    mapAccumT,
-    -- * Accum operations
-    look,
-    looks,
-    add,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCallCC',
-    liftCatch,
-    liftListen,
-    liftPass,
-    -- * Monad transformations
-    readerToAccumT,
-    writerToAccumT,
-    accumToStateT,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Trans.Class
-import Control.Monad.Trans.Reader (ReaderT(..))
-import Control.Monad.Trans.Writer (WriterT(..))
-import Control.Monad.Trans.State  (StateT(..))
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-import Control.Monad.Signatures
-#if !MIN_VERSION_base(4,8,0)
-import Data.Monoid
-#endif
-
--- ---------------------------------------------------------------------------
--- | An accumulation monad parameterized by the type @w@ of output to accumulate.
---
--- The 'return' function produces the output 'mempty', while @>>=@
--- combines the outputs of the subcomputations using 'mappend'.
-type Accum w = AccumT w Identity
-
--- | Construct an accumulation computation from a (result, output) pair.
--- (The inverse of 'runAccum'.)
-accum :: (Monad m) => (w -> (a, w)) -> AccumT w m a
-accum f = AccumT $ \ w -> return (f w)
-{-# INLINE accum #-}
-
--- | Unwrap an accumulation computation as a (result, output) pair.
--- (The inverse of 'accum'.)
-runAccum :: Accum w a -> w -> (a, w)
-runAccum m = runIdentity . runAccumT m
-{-# INLINE runAccum #-}
-
--- | Extract the output from an accumulation computation.
---
--- * @'execAccum' m w = 'snd' ('runAccum' m w)@
-execAccum :: Accum w a -> w -> w
-execAccum m w = snd (runAccum m w)
-{-# INLINE execAccum #-}
-
--- | Evaluate an accumulation computation with the given initial output history
--- and return the final value, discarding the final output.
---
--- * @'evalAccum' m w = 'fst' ('runAccum' m w)@
-evalAccum :: (Monoid w) => Accum w a -> w -> a
-evalAccum m w = fst (runAccum m w)
-{-# INLINE evalAccum #-}
-
--- | Map both the return value and output of a computation using
--- the given function.
---
--- * @'runAccum' ('mapAccum' f m) = f . 'runAccum' m@
-mapAccum :: ((a, w) -> (b, w)) -> Accum w a -> Accum w b
-mapAccum f = mapAccumT (Identity . f . runIdentity)
-{-# INLINE mapAccum #-}
-
--- ---------------------------------------------------------------------------
--- | An accumulation monad parameterized by:
---
---   * @w@ - the output to accumulate.
---
---   * @m@ - The inner monad.
---
--- The 'return' function produces the output 'mempty', while @>>=@
--- combines the outputs of the subcomputations using 'mappend'.
---
--- This monad transformer is similar to both state and writer monad transformers.
--- Thus it can be seen as
---
---  * a restricted append-only version of a state monad transformer or
---
---  * a writer monad transformer with the extra ability to read all previous output.
-newtype AccumT w m a = AccumT (w -> m (a, w))
-
--- | Unwrap an accumulation computation.
-runAccumT :: AccumT w m a -> w -> m (a, w)
-runAccumT (AccumT f) = f
-{-# INLINE runAccumT #-}
-
--- | Extract the output from an accumulation computation.
---
--- * @'execAccumT' m w = 'liftM' 'snd' ('runAccumT' m w)@
-execAccumT :: (Monad m) => AccumT w m a -> w -> m w
-execAccumT m w = do
-    ~(_, w') <- runAccumT m w
-    return w'
-{-# INLINE execAccumT #-}
-
--- | Evaluate an accumulation computation with the given initial output history
--- and return the final value, discarding the final output.
---
--- * @'evalAccumT' m w = 'liftM' 'fst' ('runAccumT' m w)@
-evalAccumT :: (Monad m, Monoid w) => AccumT w m a -> w -> m a
-evalAccumT m w = do
-    ~(a, _) <- runAccumT m w
-    return a
-{-# INLINE evalAccumT #-}
-
--- | Map both the return value and output of a computation using
--- the given function.
---
--- * @'runAccumT' ('mapAccumT' f m) = f . 'runAccumT' m@
-mapAccumT :: (m (a, w) -> n (b, w)) -> AccumT w m a -> AccumT w n b
-mapAccumT f m = AccumT (f . runAccumT m)
-{-# INLINE mapAccumT #-}
-
-instance (Functor m) => Functor (AccumT w m) where
-    fmap f = mapAccumT $ fmap $ \ ~(a, w) -> (f a, w)
-    {-# INLINE fmap #-}
-
-instance (Monoid w, Functor m, Monad m) => Applicative (AccumT w m) where
-    pure a  = AccumT $ const $ return (a, mempty)
-    {-# INLINE pure #-}
-    mf <*> mv = AccumT $ \ w -> do
-      ~(f, w')  <- runAccumT mf w
-      ~(v, w'') <- runAccumT mv (w `mappend` w')
-      return (f v, w' `mappend` w'')
-    {-# INLINE (<*>) #-}
-
-instance (Monoid w, Functor m, MonadPlus m) => Alternative (AccumT w m) where
-    empty   = AccumT $ const mzero
-    {-# INLINE empty #-}
-    m <|> n = AccumT $ \ w -> runAccumT m w `mplus` runAccumT n w
-    {-# INLINE (<|>) #-}
-
-instance (Monoid w, Functor m, Monad m) => Monad (AccumT w m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a  = AccumT $ const $ return (a, mempty)
-    {-# INLINE return #-}
-#endif
-    m >>= k  = AccumT $ \ w -> do
-        ~(a, w')  <- runAccumT m w
-        ~(b, w'') <- runAccumT (k a) (w `mappend` w')
-        return (b, w' `mappend` w'')
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = AccumT $ const (fail msg)
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Monoid w, Fail.MonadFail m) => Fail.MonadFail (AccumT w m) where
-    fail msg = AccumT $ const (Fail.fail msg)
-    {-# INLINE fail #-}
-#endif
-
-instance (Monoid w, Functor m, MonadPlus m) => MonadPlus (AccumT w m) where
-    mzero       = AccumT $ const mzero
-    {-# INLINE mzero #-}
-    m `mplus` n = AccumT $ \ w -> runAccumT m w `mplus` runAccumT n w
-    {-# INLINE mplus #-}
-
-instance (Monoid w, Functor m, MonadFix m) => MonadFix (AccumT w m) where
-    mfix m = AccumT $ \ w -> mfix $ \ ~(a, _) -> runAccumT (m a) w
-    {-# INLINE mfix #-}
-
-instance (Monoid w) => MonadTrans (AccumT w) where
-    lift m = AccumT $ const $ do
-        a <- m
-        return (a, mempty)
-    {-# INLINE lift #-}
-
-instance (Monoid w, Functor m, MonadIO m) => MonadIO (AccumT w m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
--- | @'look'@ is an action that fetches all the previously accumulated output.
-look :: (Monoid w, Monad m) => AccumT w m w
-look = AccumT $ \ w -> return (w, mempty)
-
--- | @'look'@ is an action that retrieves a function of the previously accumulated output.
-looks :: (Monoid w, Monad m) => (w -> a) -> AccumT w m a
-looks f = AccumT $ \ w -> return (f w, mempty)
-
--- | @'add' w@ is an action that produces the output @w@.
-add :: (Monad m) => w -> AccumT w m ()
-add w = accum $ const ((), w)
-{-# INLINE add #-}
-
--- | Uniform lifting of a @callCC@ operation to the new monad.
--- This version rolls back to the original output history on entering the
--- continuation.
-liftCallCC :: CallCC m (a, w) (b, w) -> CallCC (AccumT w m) a b
-liftCallCC callCC f = AccumT $ \ w ->
-    callCC $ \ c ->
-    runAccumT (f (\ a -> AccumT $ \ _ -> c (a, w))) w
-{-# INLINE liftCallCC #-}
-
--- | In-situ lifting of a @callCC@ operation to the new monad.
--- This version uses the current output history on entering the continuation.
--- It does not satisfy the uniformity property (see "Control.Monad.Signatures").
-liftCallCC' :: CallCC m (a, w) (b, w) -> CallCC (AccumT w m) a b
-liftCallCC' callCC f = AccumT $ \ s ->
-    callCC $ \ c ->
-    runAccumT (f (\ a -> AccumT $ \ s' -> c (a, s'))) s
-{-# INLINE liftCallCC' #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a, w) -> Catch e (AccumT w m) a
-liftCatch catchE m h =
-    AccumT $ \ w -> runAccumT m w `catchE` \ e -> runAccumT (h e) w
-{-# INLINE liftCatch #-}
-
--- | Lift a @listen@ operation to the new monad.
-liftListen :: (Monad m) => Listen w m (a, s) -> Listen w (AccumT s m) a
-liftListen listen m = AccumT $ \ s -> do
-    ~((a, s'), w) <- listen (runAccumT m s)
-    return ((a, w), s')
-{-# INLINE liftListen #-}
-
--- | Lift a @pass@ operation to the new monad.
-liftPass :: (Monad m) => Pass w m (a, s) -> Pass w (AccumT s m) a
-liftPass pass m = AccumT $ \ s -> pass $ do
-    ~((a, f), s') <- runAccumT m s
-    return ((a, s'), f)
-{-# INLINE liftPass #-}
-
--- | Convert a read-only computation into an accumulation computation.
-readerToAccumT :: (Functor m, Monoid w) => ReaderT w m a -> AccumT w m a
-readerToAccumT (ReaderT f) = AccumT $ \ w -> fmap (\ a -> (a, mempty)) (f w)
-{-# INLINE readerToAccumT #-}
-
--- | Convert a writer computation into an accumulation computation.
-writerToAccumT :: WriterT w m a -> AccumT w m a
-writerToAccumT (WriterT m) = AccumT $ const $ m
-{-# INLINE writerToAccumT #-}
-
--- | Convert an accumulation (append-only) computation into a fully
--- stateful computation.
-accumToStateT :: (Functor m, Monoid s) => AccumT s m a -> StateT s m a
-accumToStateT (AccumT f) =
-    StateT $ \ w -> fmap (\ ~(a, w') -> (a, w `mappend` w')) (f w)
-{-# INLINE accumToStateT #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Class.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Class.hs
deleted file mode 100644
index b92bc0e8b0f6..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Class.hs
+++ /dev/null
@@ -1,262 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Class
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The class of monad transformers.
---
--- A monad transformer makes a new monad out of an existing monad, such
--- that computations of the old monad may be embedded in the new one.
--- To construct a monad with a desired set of features, one typically
--- starts with a base monad, such as 'Data.Functor.Identity.Identity', @[]@ or 'IO', and
--- applies a sequence of monad transformers.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Class (
-    -- * Transformer class
-    MonadTrans(..)
-
-    -- * Conventions
-    -- $conventions
-
-    -- * Strict monads
-    -- $strict
-
-    -- * Examples
-    -- ** Parsing
-    -- $example1
-
-    -- ** Parsing and counting
-    -- $example2
-
-    -- ** Interpreter monad
-    -- $example3
-  ) where
-
--- | The class of monad transformers.  Instances should satisfy the
--- following laws, which state that 'lift' is a monad transformation:
---
--- * @'lift' . 'return' = 'return'@
---
--- * @'lift' (m >>= f) = 'lift' m >>= ('lift' . f)@
-
-class MonadTrans t where
-    -- | Lift a computation from the argument monad to the constructed monad.
-    lift :: (Monad m) => m a -> t m a
-
-{- $conventions
-Most monad transformer modules include the special case of applying
-the transformer to 'Data.Functor.Identity.Identity'.  For example,
-@'Control.Monad.Trans.State.Lazy.State' s@ is an abbreviation for
-@'Control.Monad.Trans.State.Lazy.StateT' s 'Data.Functor.Identity.Identity'@.
-
-Each monad transformer also comes with an operation @run@/XXX/@T@ to
-unwrap the transformer, exposing a computation of the inner monad.
-(Currently these functions are defined as field labels, but in the next
-major release they will be separate functions.)
-
-All of the monad transformers except 'Control.Monad.Trans.Cont.ContT'
-and 'Control.Monad.Trans.Cont.SelectT' are functors on the category
-of monads: in addition to defining a mapping of monads, they
-also define a mapping from transformations between base monads to
-transformations between transformed monads, called @map@/XXX/@T@.
-Thus given a monad transformation @t :: M a -> N a@, the combinator
-'Control.Monad.Trans.State.Lazy.mapStateT' constructs a monad
-transformation
-
-> mapStateT t :: StateT s M a -> StateT s N a
-
-For these monad transformers, 'lift' is a natural transformation in the
-category of monads, i.e. for any monad transformation @t :: M a -> N a@,
-
-* @map@/XXX/@T t . 'lift' = 'lift' . t@
-
-Each of the monad transformers introduces relevant operations.
-In a sequence of monad transformers, most of these operations.can be
-lifted through other transformers using 'lift' or the @map@/XXX/@T@
-combinator, but a few with more complex type signatures require
-specialized lifting combinators, called @lift@/Op/
-(see "Control.Monad.Signatures").
--}
-
-{- $strict
-
-A monad is said to be /strict/ if its '>>=' operation is strict in its first
-argument.  The base monads 'Maybe', @[]@ and 'IO' are strict:
-
->>> undefined >> return 2 :: Maybe Integer
-*** Exception: Prelude.undefined
-
-However the monad 'Data.Functor.Identity.Identity' is not:
-
->>> runIdentity (undefined >> return 2)
-2
-
-In a strict monad you know when each action is executed, but the monad
-is not necessarily strict in the return value, or in other components
-of the monad, such as a state.  However you can use 'seq' to create
-an action that is strict in the component you want evaluated.
--}
-
-{- $example1
-
-The first example is a parser monad in the style of
-
-* \"Monadic parsing in Haskell\", by Graham Hutton and Erik Meijer,
-/Journal of Functional Programming/ 8(4):437-444, July 1998
-(<http://www.cs.nott.ac.uk/~pszgmh/bib.html#pearl>).
-
-We can define such a parser monad by adding a state (the 'String' remaining
-to be parsed) to the @[]@ monad, which provides non-determinism:
-
-> import Control.Monad.Trans.State
->
-> type Parser = StateT String []
-
-Then @Parser@ is an instance of @MonadPlus@: monadic sequencing implements
-concatenation of parsers, while @mplus@ provides choice.  To use parsers,
-we need a primitive to run a constructed parser on an input string:
-
-> runParser :: Parser a -> String -> [a]
-> runParser p s = [x | (x, "") <- runStateT p s]
-
-Finally, we need a primitive parser that matches a single character,
-from which arbitrarily complex parsers may be constructed:
-
-> item :: Parser Char
-> item = do
->     c:cs <- get
->     put cs
->     return c
-
-In this example we use the operations @get@ and @put@ from
-"Control.Monad.Trans.State", which are defined only for monads that are
-applications of 'Control.Monad.Trans.State.Lazy.StateT'.  Alternatively one
-could use monad classes from the @mtl@ package or similar, which contain
-methods @get@ and @put@ with types generalized over all suitable monads.
--}
-
-{- $example2
-
-We can define a parser that also counts by adding a
-'Control.Monad.Trans.Writer.Lazy.WriterT' transformer:
-
-> import Control.Monad.Trans.Class
-> import Control.Monad.Trans.State
-> import Control.Monad.Trans.Writer
-> import Data.Monoid
->
-> type Parser = WriterT (Sum Int) (StateT String [])
-
-The function that applies a parser must now unwrap each of the monad
-transformers in turn:
-
-> runParser :: Parser a -> String -> [(a, Int)]
-> runParser p s = [(x, n) | ((x, Sum n), "") <- runStateT (runWriterT p) s]
-
-To define the @item@ parser, we need to lift the
-'Control.Monad.Trans.State.Lazy.StateT' operations through the
-'Control.Monad.Trans.Writer.Lazy.WriterT' transformer.
-
-> item :: Parser Char
-> item = do
->     c:cs <- lift get
->     lift (put cs)
->     return c
-
-In this case, we were able to do this with 'lift', but operations with
-more complex types require special lifting functions, which are provided
-by monad transformers for which they can be implemented.  If you use the
-monad classes of the @mtl@ package or similar, this lifting is handled
-automatically by the instances of the classes, and you need only use
-the generalized methods @get@ and @put@.
-
-We can also define a primitive using the Writer:
-
-> tick :: Parser ()
-> tick = tell (Sum 1)
-
-Then the parser will keep track of how many @tick@s it executes.
--}
-
-{- $example3
-
-This example is a cut-down version of the one in
-
-* \"Monad Transformers and Modular Interpreters\",
-by Sheng Liang, Paul Hudak and Mark Jones in /POPL'95/
-(<http://web.cecs.pdx.edu/~mpj/pubs/modinterp.html>).
-
-Suppose we want to define an interpreter that can do I\/O and has
-exceptions, an environment and a modifiable store.  We can define
-a monad that supports all these things as a stack of monad transformers:
-
-> import Control.Monad.Trans.Class
-> import Control.Monad.Trans.State
-> import qualified Control.Monad.Trans.Reader as R
-> import qualified Control.Monad.Trans.Except as E
-> import Control.Monad.IO.Class
->
-> type InterpM = StateT Store (R.ReaderT Env (E.ExceptT Err IO))
-
-for suitable types @Store@, @Env@ and @Err@.
-
-Now we would like to be able to use the operations associated with each
-of those monad transformers on @InterpM@ actions.  Since the uppermost
-monad transformer of @InterpM@ is 'Control.Monad.Trans.State.Lazy.StateT',
-it already has the state operations @get@ and @set@.
-
-The first of the 'Control.Monad.Trans.Reader.ReaderT' operations,
-'Control.Monad.Trans.Reader.ask', is a simple action, so we can lift it
-through 'Control.Monad.Trans.State.Lazy.StateT' to @InterpM@ using 'lift':
-
-> ask :: InterpM Env
-> ask = lift R.ask
-
-The other 'Control.Monad.Trans.Reader.ReaderT' operation,
-'Control.Monad.Trans.Reader.local', has a suitable type for lifting
-using 'Control.Monad.Trans.State.Lazy.mapStateT':
-
-> local :: (Env -> Env) -> InterpM a -> InterpM a
-> local f = mapStateT (R.local f)
-
-We also wish to lift the operations of 'Control.Monad.Trans.Except.ExceptT'
-through both 'Control.Monad.Trans.Reader.ReaderT' and
-'Control.Monad.Trans.State.Lazy.StateT'.  For the operation
-'Control.Monad.Trans.Except.throwE', we know @throwE e@ is a simple
-action, so we can lift it through the two monad transformers to @InterpM@
-with two 'lift's:
-
-> throwE :: Err -> InterpM a
-> throwE e = lift (lift (E.throwE e))
-
-The 'Control.Monad.Trans.Except.catchE' operation has a more
-complex type, so we need to use the special-purpose lifting function
-@liftCatch@ provided by most monad transformers.  Here we use
-the 'Control.Monad.Trans.Reader.ReaderT' version followed by the
-'Control.Monad.Trans.State.Lazy.StateT' version:
-
-> catchE :: InterpM a -> (Err -> InterpM a) -> InterpM a
-> catchE = liftCatch (R.liftCatch E.catchE)
-
-We could lift 'IO' actions to @InterpM@ using three 'lift's, but @InterpM@
-is automatically an instance of 'Control.Monad.IO.Class.MonadIO',
-so we can use 'Control.Monad.IO.Class.liftIO' instead:
-
-> putStr :: String -> InterpM ()
-> putStr s = liftIO (Prelude.putStr s)
-
--}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Cont.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Cont.hs
deleted file mode 100644
index ce2005d4b29f..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Cont.hs
+++ /dev/null
@@ -1,240 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Cont
--- Copyright   :  (c) The University of Glasgow 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Continuation monads.
---
--- Delimited continuation operators are taken from Kenichi Asai and Oleg
--- Kiselyov's tutorial at CW 2011, \"Introduction to programming with
--- shift and reset\" (<http://okmij.org/ftp/continuations/#tutorial>).
---
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Cont (
-    -- * The Cont monad
-    Cont,
-    cont,
-    runCont,
-    evalCont,
-    mapCont,
-    withCont,
-    -- ** Delimited continuations
-    reset, shift,
-    -- * The ContT monad transformer
-    ContT(..),
-    evalContT,
-    mapContT,
-    withContT,
-    callCC,
-    -- ** Delimited continuations
-    resetT, shiftT,
-    -- * Lifting other operations
-    liftLocal,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Trans.Class
-import Data.Functor.Identity
-
-import Control.Applicative
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-
-{- |
-Continuation monad.
-@Cont r a@ is a CPS ("continuation-passing style") computation that produces an
-intermediate result of type @a@ within a CPS computation whose final result type
-is @r@.
-
-The @return@ function simply creates a continuation which passes the value on.
-
-The @>>=@ operator adds the bound function into the continuation chain.
--}
-type Cont r = ContT r Identity
-
--- | Construct a continuation-passing computation from a function.
--- (The inverse of 'runCont')
-cont :: ((a -> r) -> r) -> Cont r a
-cont f = ContT (\ c -> Identity (f (runIdentity . c)))
-{-# INLINE cont #-}
-
--- | The result of running a CPS computation with a given final continuation.
--- (The inverse of 'cont')
-runCont
-    :: Cont r a         -- ^ continuation computation (@Cont@).
-    -> (a -> r)         -- ^ the final continuation, which produces
-                        -- the final result (often 'id').
-    -> r
-runCont m k = runIdentity (runContT m (Identity . k))
-{-# INLINE runCont #-}
-
--- | The result of running a CPS computation with the identity as the
--- final continuation.
---
--- * @'evalCont' ('return' x) = x@
-evalCont :: Cont r r -> r
-evalCont m = runIdentity (evalContT m)
-{-# INLINE evalCont #-}
-
--- | Apply a function to transform the result of a continuation-passing
--- computation.
---
--- * @'runCont' ('mapCont' f m) = f . 'runCont' m@
-mapCont :: (r -> r) -> Cont r a -> Cont r a
-mapCont f = mapContT (Identity . f . runIdentity)
-{-# INLINE mapCont #-}
-
--- | Apply a function to transform the continuation passed to a CPS
--- computation.
---
--- * @'runCont' ('withCont' f m) = 'runCont' m . f@
-withCont :: ((b -> r) -> (a -> r)) -> Cont r a -> Cont r b
-withCont f = withContT ((Identity .) . f . (runIdentity .))
-{-# INLINE withCont #-}
-
--- | @'reset' m@ delimits the continuation of any 'shift' inside @m@.
---
--- * @'reset' ('return' m) = 'return' m@
---
-reset :: Cont r r -> Cont r' r
-reset = resetT
-{-# INLINE reset #-}
-
--- | @'shift' f@ captures the continuation up to the nearest enclosing
--- 'reset' and passes it to @f@:
---
--- * @'reset' ('shift' f >>= k) = 'reset' (f ('evalCont' . k))@
---
-shift :: ((a -> r) -> Cont r r) -> Cont r a
-shift f = shiftT (f . (runIdentity .))
-{-# INLINE shift #-}
-
--- | The continuation monad transformer.
--- Can be used to add continuation handling to any type constructor:
--- the 'Monad' instance and most of the operations do not require @m@
--- to be a monad.
---
--- 'ContT' is not a functor on the category of monads, and many operations
--- cannot be lifted through it.
-newtype ContT r m a = ContT { runContT :: (a -> m r) -> m r }
-
--- | The result of running a CPS computation with 'return' as the
--- final continuation.
---
--- * @'evalContT' ('lift' m) = m@
-evalContT :: (Monad m) => ContT r m r -> m r
-evalContT m = runContT m return
-{-# INLINE evalContT #-}
-
--- | Apply a function to transform the result of a continuation-passing
--- computation.  This has a more restricted type than the @map@ operations
--- for other monad transformers, because 'ContT' does not define a functor
--- in the category of monads.
---
--- * @'runContT' ('mapContT' f m) = f . 'runContT' m@
-mapContT :: (m r -> m r) -> ContT r m a -> ContT r m a
-mapContT f m = ContT $ f . runContT m
-{-# INLINE mapContT #-}
-
--- | Apply a function to transform the continuation passed to a CPS
--- computation.
---
--- * @'runContT' ('withContT' f m) = 'runContT' m . f@
-withContT :: ((b -> m r) -> (a -> m r)) -> ContT r m a -> ContT r m b
-withContT f m = ContT $ runContT m . f
-{-# INLINE withContT #-}
-
-instance Functor (ContT r m) where
-    fmap f m = ContT $ \ c -> runContT m (c . f)
-    {-# INLINE fmap #-}
-
-instance Applicative (ContT r m) where
-    pure x  = ContT ($ x)
-    {-# INLINE pure #-}
-    f <*> v = ContT $ \ c -> runContT f $ \ g -> runContT v (c . g)
-    {-# INLINE (<*>) #-}
-    m *> k = m >>= \_ -> k
-    {-# INLINE (*>) #-}
-
-instance Monad (ContT r m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return x = ContT ($ x)
-    {-# INLINE return #-}
-#endif
-    m >>= k  = ContT $ \ c -> runContT m (\ x -> runContT (k x) c)
-    {-# INLINE (>>=) #-}
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (ContT r m) where
-    fail msg = ContT $ \ _ -> Fail.fail msg
-    {-# INLINE fail #-}
-#endif
-
-instance MonadTrans (ContT r) where
-    lift m = ContT (m >>=)
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (ContT r m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
--- | @callCC@ (call-with-current-continuation) calls its argument
--- function, passing it the current continuation.  It provides
--- an escape continuation mechanism for use with continuation
--- monads.  Escape continuations one allow to abort the current
--- computation and return a value immediately.  They achieve
--- a similar effect to 'Control.Monad.Trans.Except.throwE'
--- and 'Control.Monad.Trans.Except.catchE' within an
--- 'Control.Monad.Trans.Except.ExceptT' monad.  The advantage of this
--- function over calling 'return' is that it makes the continuation
--- explicit, allowing more flexibility and better control.
---
--- The standard idiom used with @callCC@ is to provide a lambda-expression
--- to name the continuation. Then calling the named continuation anywhere
--- within its scope will escape from the computation, even if it is many
--- layers deep within nested computations.
-callCC :: ((a -> ContT r m b) -> ContT r m a) -> ContT r m a
-callCC f = ContT $ \ c -> runContT (f (\ x -> ContT $ \ _ -> c x)) c
-{-# INLINE callCC #-}
-
--- | @'resetT' m@ delimits the continuation of any 'shiftT' inside @m@.
---
--- * @'resetT' ('lift' m) = 'lift' m@
---
-resetT :: (Monad m) => ContT r m r -> ContT r' m r
-resetT = lift . evalContT
-{-# INLINE resetT #-}
-
--- | @'shiftT' f@ captures the continuation up to the nearest enclosing
--- 'resetT' and passes it to @f@:
---
--- * @'resetT' ('shiftT' f >>= k) = 'resetT' (f ('evalContT' . k))@
---
-shiftT :: (Monad m) => ((a -> m r) -> ContT r m r) -> ContT r m a
-shiftT f = ContT (evalContT . f)
-{-# INLINE shiftT #-}
-
--- | @'liftLocal' ask local@ yields a @local@ function for @'ContT' r m@.
-liftLocal :: (Monad m) => m r' -> ((r' -> r') -> m r -> m r) ->
-    (r' -> r') -> ContT r m a -> ContT r m a
-liftLocal ask local f m = ContT $ \ c -> do
-    r <- ask
-    local f (runContT m (local (const r) . c))
-{-# INLINE liftLocal #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Error.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Error.hs
deleted file mode 100644
index 6eda4b3e015a..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Error.hs
+++ /dev/null
@@ -1,333 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
-#if !(MIN_VERSION_base(4,9,0))
-{-# OPTIONS_GHC -fno-warn-orphans #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Error
--- Copyright   :  (c) Michael Weber <michael.weber@post.rwth-aachen.de> 2001,
---                (c) Jeff Newbern 2003-2006,
---                (c) Andriy Palamarchuk 2006
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- This monad transformer adds the ability to fail or throw exceptions
--- to a monad.
---
--- A sequence of actions succeeds, producing a value, only if all the
--- actions in the sequence are successful.  If one fails with an error,
--- the rest of the sequence is skipped and the composite action fails
--- with that error.
---
--- If the value of the error is not required, the variant in
--- "Control.Monad.Trans.Maybe" may be used instead.
---
--- /Note:/ This module will be removed in a future release.
--- Instead, use "Control.Monad.Trans.Except", which does not restrict
--- the exception type, and also includes a base exception monad.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Error
-  {-# DEPRECATED "Use Control.Monad.Trans.Except instead" #-} (
-    -- * The ErrorT monad transformer
-    Error(..),
-    ErrorList(..),
-    ErrorT(..),
-    mapErrorT,
-    -- * Error operations
-    throwError,
-    catchError,
-    -- * Lifting other operations
-    liftCallCC,
-    liftListen,
-    liftPass,
-    -- * Examples
-    -- $examples
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-
-import Control.Applicative
-import Control.Exception (IOException)
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-#if !(MIN_VERSION_base(4,6,0))
-import Control.Monad.Instances ()  -- deprecated from base-4.6
-#endif
-import Data.Foldable (Foldable(foldMap))
-import Data.Monoid (mempty)
-import Data.Traversable (Traversable(traverse))
-import System.IO.Error
-
-#if !(MIN_VERSION_base(4,9,0))
--- These instances are in base-4.9.0
-
-instance MonadPlus IO where
-    mzero       = ioError (userError "mzero")
-    m `mplus` n = m `catchIOError` \ _ -> n
-
-instance Alternative IO where
-    empty = mzero
-    (<|>) = mplus
-
-# if !(MIN_VERSION_base(4,4,0))
--- exported by System.IO.Error from base-4.4
-catchIOError :: IO a -> (IOError -> IO a) -> IO a
-catchIOError = catch
-# endif
-#endif
-
-instance (Error e) => Alternative (Either e) where
-    empty        = Left noMsg
-    Left _ <|> n = n
-    m      <|> _ = m
-
-instance (Error e) => MonadPlus (Either e) where
-    mzero            = Left noMsg
-    Left _ `mplus` n = n
-    m      `mplus` _ = m
-
-#if !(MIN_VERSION_base(4,3,0))
--- These instances are in base-4.3
-
-instance Applicative (Either e) where
-    pure          = Right
-    Left  e <*> _ = Left e
-    Right f <*> r = fmap f r
-
-instance Monad (Either e) where
-    return        = Right
-    Left  l >>= _ = Left l
-    Right r >>= k = k r
-
-instance MonadFix (Either e) where
-    mfix f = let
-        a = f $ case a of
-            Right r -> r
-            _       -> error "empty mfix argument"
-        in a
-
-#endif /* base to 4.2.0.x */
-
--- | An exception to be thrown.
---
--- Minimal complete definition: 'noMsg' or 'strMsg'.
-class Error a where
-    -- | Creates an exception without a message.
-    -- The default implementation is @'strMsg' \"\"@.
-    noMsg  :: a
-    -- | Creates an exception with a message.
-    -- The default implementation of @'strMsg' s@ is 'noMsg'.
-    strMsg :: String -> a
-
-    noMsg    = strMsg ""
-    strMsg _ = noMsg
-
-instance Error IOException where
-    strMsg = userError
-
--- | A string can be thrown as an error.
-instance (ErrorList a) => Error [a] where
-    strMsg = listMsg
-
--- | Workaround so that we can have a Haskell 98 instance @'Error' 'String'@.
-class ErrorList a where
-    listMsg :: String -> [a]
-
-instance ErrorList Char where
-    listMsg = id
-
--- | The error monad transformer. It can be used to add error handling
--- to other monads.
---
--- The @ErrorT@ Monad structure is parameterized over two things:
---
--- * e - The error type.
---
--- * m - The inner monad.
---
--- The 'return' function yields a successful computation, while @>>=@
--- sequences two subcomputations, failing on the first error.
-newtype ErrorT e m a = ErrorT { runErrorT :: m (Either e a) }
-
-instance (Eq e, Eq1 m) => Eq1 (ErrorT e m) where
-    liftEq eq (ErrorT x) (ErrorT y) = liftEq (liftEq eq) x y
-
-instance (Ord e, Ord1 m) => Ord1 (ErrorT e m) where
-    liftCompare comp (ErrorT x) (ErrorT y) = liftCompare (liftCompare comp) x y
-
-instance (Read e, Read1 m) => Read1 (ErrorT e m) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp' rl') "ErrorT" ErrorT
-      where
-        rp' = liftReadsPrec rp rl
-        rl' = liftReadList rp rl
-
-instance (Show e, Show1 m) => Show1 (ErrorT e m) where
-    liftShowsPrec sp sl d (ErrorT m) =
-        showsUnaryWith (liftShowsPrec sp' sl') "ErrorT" d m
-      where
-        sp' = liftShowsPrec sp sl
-        sl' = liftShowList sp sl
-
-instance (Eq e, Eq1 m, Eq a) => Eq (ErrorT e m a) where (==) = eq1
-instance (Ord e, Ord1 m, Ord a) => Ord (ErrorT e m a) where compare = compare1
-instance (Read e, Read1 m, Read a) => Read (ErrorT e m a) where
-    readsPrec = readsPrec1
-instance (Show e, Show1 m, Show a) => Show (ErrorT e m a) where
-    showsPrec = showsPrec1
-
--- | Map the unwrapped computation using the given function.
---
--- * @'runErrorT' ('mapErrorT' f m) = f ('runErrorT' m)@
-mapErrorT :: (m (Either e a) -> n (Either e' b))
-          -> ErrorT e m a
-          -> ErrorT e' n b
-mapErrorT f m = ErrorT $ f (runErrorT m)
-
-instance (Functor m) => Functor (ErrorT e m) where
-    fmap f = ErrorT . fmap (fmap f) . runErrorT
-
-instance (Foldable f) => Foldable (ErrorT e f) where
-    foldMap f (ErrorT a) = foldMap (either (const mempty) f) a
-
-instance (Traversable f) => Traversable (ErrorT e f) where
-    traverse f (ErrorT a) =
-        ErrorT <$> traverse (either (pure . Left) (fmap Right . f)) a
-
-instance (Functor m, Monad m) => Applicative (ErrorT e m) where
-    pure a  = ErrorT $ return (Right a)
-    f <*> v = ErrorT $ do
-        mf <- runErrorT f
-        case mf of
-            Left  e -> return (Left e)
-            Right k -> do
-                mv <- runErrorT v
-                case mv of
-                    Left  e -> return (Left e)
-                    Right x -> return (Right (k x))
-
-instance (Functor m, Monad m, Error e) => Alternative (ErrorT e m) where
-    empty = mzero
-    (<|>) = mplus
-
-instance (Monad m, Error e) => Monad (ErrorT e m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = ErrorT $ return (Right a)
-#endif
-    m >>= k  = ErrorT $ do
-        a <- runErrorT m
-        case a of
-            Left  l -> return (Left l)
-            Right r -> runErrorT (k r)
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = ErrorT $ return (Left (strMsg msg))
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Monad m, Error e) => Fail.MonadFail (ErrorT e m) where
-    fail msg = ErrorT $ return (Left (strMsg msg))
-#endif
-
-instance (Monad m, Error e) => MonadPlus (ErrorT e m) where
-    mzero       = ErrorT $ return (Left noMsg)
-    m `mplus` n = ErrorT $ do
-        a <- runErrorT m
-        case a of
-            Left  _ -> runErrorT n
-            Right r -> return (Right r)
-
-instance (MonadFix m, Error e) => MonadFix (ErrorT e m) where
-    mfix f = ErrorT $ mfix $ \ a -> runErrorT $ f $ case a of
-        Right r -> r
-        _       -> error "empty mfix argument"
-
-instance MonadTrans (ErrorT e) where
-    lift m = ErrorT $ do
-        a <- m
-        return (Right a)
-
-instance (Error e, MonadIO m) => MonadIO (ErrorT e m) where
-    liftIO = lift . liftIO
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (ErrorT e m) where
-    contramap f = ErrorT . contramap (fmap f) . runErrorT
-#endif
-
--- | Signal an error value @e@.
---
--- * @'runErrorT' ('throwError' e) = 'return' ('Left' e)@
---
--- * @'throwError' e >>= m = 'throwError' e@
-throwError :: (Monad m) => e -> ErrorT e m a
-throwError l = ErrorT $ return (Left l)
-
--- | Handle an error.
---
--- * @'catchError' h ('lift' m) = 'lift' m@
---
--- * @'catchError' h ('throwError' e) = h e@
-catchError :: (Monad m) =>
-    ErrorT e m a                -- ^ the inner computation
-    -> (e -> ErrorT e m a)      -- ^ a handler for errors in the inner
-                                -- computation
-    -> ErrorT e m a
-m `catchError` h = ErrorT $ do
-    a <- runErrorT m
-    case a of
-        Left  l -> runErrorT (h l)
-        Right r -> return (Right r)
-
--- | Lift a @callCC@ operation to the new monad.
-liftCallCC :: CallCC m (Either e a) (Either e b) -> CallCC (ErrorT e m) a b
-liftCallCC callCC f = ErrorT $
-    callCC $ \ c ->
-    runErrorT (f (\ a -> ErrorT $ c (Right a)))
-
--- | Lift a @listen@ operation to the new monad.
-liftListen :: (Monad m) => Listen w m (Either e a) -> Listen w (ErrorT e m) a
-liftListen listen = mapErrorT $ \ m -> do
-    (a, w) <- listen m
-    return $! fmap (\ r -> (r, w)) a
-
--- | Lift a @pass@ operation to the new monad.
-liftPass :: (Monad m) => Pass w m (Either e a) -> Pass w (ErrorT e m) a
-liftPass pass = mapErrorT $ \ m -> pass $ do
-    a <- m
-    return $! case a of
-        Left  l      -> (Left  l, id)
-        Right (r, f) -> (Right r, f)
-
-{- $examples
-
-Wrapping an IO action that can throw an error @e@:
-
-> type ErrorWithIO e a = ErrorT e IO a
-> ==> ErrorT (IO (Either e a))
-
-An IO monad wrapped in @StateT@ inside of @ErrorT@:
-
-> type ErrorAndStateWithIO e s a = ErrorT e (StateT s IO) a
-> ==> ErrorT (StateT s IO (Either e a))
-> ==> ErrorT (StateT (s -> IO (Either e a,s)))
-
--}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Except.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Except.hs
deleted file mode 100644
index 477b9dd4826c..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Except.hs
+++ /dev/null
@@ -1,316 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Except
--- Copyright   :  (C) 2013 Ross Paterson
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- This monad transformer extends a monad with the ability to throw exceptions.
---
--- A sequence of actions terminates normally, producing a value,
--- only if none of the actions in the sequence throws an exception.
--- If one throws an exception, the rest of the sequence is skipped and
--- the composite action exits with that exception.
---
--- If the value of the exception is not required, the variant in
--- "Control.Monad.Trans.Maybe" may be used instead.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Except (
-    -- * The Except monad
-    Except,
-    except,
-    runExcept,
-    mapExcept,
-    withExcept,
-    -- * The ExceptT monad transformer
-    ExceptT(ExceptT),
-    runExceptT,
-    mapExceptT,
-    withExceptT,
-    -- * Exception operations
-    throwE,
-    catchE,
-    -- * Lifting other operations
-    liftCallCC,
-    liftListen,
-    liftPass,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith))
-#endif
-import Data.Foldable (Foldable(foldMap))
-import Data.Monoid
-import Data.Traversable (Traversable(traverse))
-
--- | The parameterizable exception monad.
---
--- Computations are either exceptions or normal values.
---
--- The 'return' function returns a normal value, while @>>=@ exits on
--- the first exception.  For a variant that continues after an error
--- and collects all the errors, see 'Control.Applicative.Lift.Errors'.
-type Except e = ExceptT e Identity
-
--- | Constructor for computations in the exception monad.
--- (The inverse of 'runExcept').
-except :: (Monad m) => Either e a -> ExceptT e m a
-except m = ExceptT (return m)
-{-# INLINE except #-}
-
--- | Extractor for computations in the exception monad.
--- (The inverse of 'except').
-runExcept :: Except e a -> Either e a
-runExcept (ExceptT m) = runIdentity m
-{-# INLINE runExcept #-}
-
--- | Map the unwrapped computation using the given function.
---
--- * @'runExcept' ('mapExcept' f m) = f ('runExcept' m)@
-mapExcept :: (Either e a -> Either e' b)
-        -> Except e a
-        -> Except e' b
-mapExcept f = mapExceptT (Identity . f . runIdentity)
-{-# INLINE mapExcept #-}
-
--- | Transform any exceptions thrown by the computation using the given
--- function (a specialization of 'withExceptT').
-withExcept :: (e -> e') -> Except e a -> Except e' a
-withExcept = withExceptT
-{-# INLINE withExcept #-}
-
--- | A monad transformer that adds exceptions to other monads.
---
--- @ExceptT@ constructs a monad parameterized over two things:
---
--- * e - The exception type.
---
--- * m - The inner monad.
---
--- The 'return' function yields a computation that produces the given
--- value, while @>>=@ sequences two subcomputations, exiting on the
--- first exception.
-newtype ExceptT e m a = ExceptT (m (Either e a))
-
-instance (Eq e, Eq1 m) => Eq1 (ExceptT e m) where
-    liftEq eq (ExceptT x) (ExceptT y) = liftEq (liftEq eq) x y
-    {-# INLINE liftEq #-}
-
-instance (Ord e, Ord1 m) => Ord1 (ExceptT e m) where
-    liftCompare comp (ExceptT x) (ExceptT y) =
-        liftCompare (liftCompare comp) x y
-    {-# INLINE liftCompare #-}
-
-instance (Read e, Read1 m) => Read1 (ExceptT e m) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp' rl') "ExceptT" ExceptT
-      where
-        rp' = liftReadsPrec rp rl
-        rl' = liftReadList rp rl
-
-instance (Show e, Show1 m) => Show1 (ExceptT e m) where
-    liftShowsPrec sp sl d (ExceptT m) =
-        showsUnaryWith (liftShowsPrec sp' sl') "ExceptT" d m
-      where
-        sp' = liftShowsPrec sp sl
-        sl' = liftShowList sp sl
-
-instance (Eq e, Eq1 m, Eq a) => Eq (ExceptT e m a)
-    where (==) = eq1
-instance (Ord e, Ord1 m, Ord a) => Ord (ExceptT e m a)
-    where compare = compare1
-instance (Read e, Read1 m, Read a) => Read (ExceptT e m a) where
-    readsPrec = readsPrec1
-instance (Show e, Show1 m, Show a) => Show (ExceptT e m a) where
-    showsPrec = showsPrec1
-
--- | The inverse of 'ExceptT'.
-runExceptT :: ExceptT e m a -> m (Either e a)
-runExceptT (ExceptT m) = m
-{-# INLINE runExceptT #-}
-
--- | Map the unwrapped computation using the given function.
---
--- * @'runExceptT' ('mapExceptT' f m) = f ('runExceptT' m)@
-mapExceptT :: (m (Either e a) -> n (Either e' b))
-        -> ExceptT e m a
-        -> ExceptT e' n b
-mapExceptT f m = ExceptT $ f (runExceptT m)
-{-# INLINE mapExceptT #-}
-
--- | Transform any exceptions thrown by the computation using the
--- given function.
-withExceptT :: (Functor m) => (e -> e') -> ExceptT e m a -> ExceptT e' m a
-withExceptT f = mapExceptT $ fmap $ either (Left . f) Right
-{-# INLINE withExceptT #-}
-
-instance (Functor m) => Functor (ExceptT e m) where
-    fmap f = ExceptT . fmap (fmap f) . runExceptT
-    {-# INLINE fmap #-}
-
-instance (Foldable f) => Foldable (ExceptT e f) where
-    foldMap f (ExceptT a) = foldMap (either (const mempty) f) a
-    {-# INLINE foldMap #-}
-
-instance (Traversable f) => Traversable (ExceptT e f) where
-    traverse f (ExceptT a) =
-        ExceptT <$> traverse (either (pure . Left) (fmap Right . f)) a
-    {-# INLINE traverse #-}
-
-instance (Functor m, Monad m) => Applicative (ExceptT e m) where
-    pure a = ExceptT $ return (Right a)
-    {-# INLINE pure #-}
-    ExceptT f <*> ExceptT v = ExceptT $ do
-        mf <- f
-        case mf of
-            Left e -> return (Left e)
-            Right k -> do
-                mv <- v
-                case mv of
-                    Left e -> return (Left e)
-                    Right x -> return (Right (k x))
-    {-# INLINEABLE (<*>) #-}
-    m *> k = m >>= \_ -> k
-    {-# INLINE (*>) #-}
-
-instance (Functor m, Monad m, Monoid e) => Alternative (ExceptT e m) where
-    empty = ExceptT $ return (Left mempty)
-    {-# INLINE empty #-}
-    ExceptT mx <|> ExceptT my = ExceptT $ do
-        ex <- mx
-        case ex of
-            Left e -> liftM (either (Left . mappend e) Right) my
-            Right x -> return (Right x)
-    {-# INLINEABLE (<|>) #-}
-
-instance (Monad m) => Monad (ExceptT e m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = ExceptT $ return (Right a)
-    {-# INLINE return #-}
-#endif
-    m >>= k = ExceptT $ do
-        a <- runExceptT m
-        case a of
-            Left e -> return (Left e)
-            Right x -> runExceptT (k x)
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail = ExceptT . fail
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (ExceptT e m) where
-    fail = ExceptT . Fail.fail
-    {-# INLINE fail #-}
-#endif
-
-instance (Monad m, Monoid e) => MonadPlus (ExceptT e m) where
-    mzero = ExceptT $ return (Left mempty)
-    {-# INLINE mzero #-}
-    ExceptT mx `mplus` ExceptT my = ExceptT $ do
-        ex <- mx
-        case ex of
-            Left e -> liftM (either (Left . mappend e) Right) my
-            Right x -> return (Right x)
-    {-# INLINEABLE mplus #-}
-
-instance (MonadFix m) => MonadFix (ExceptT e m) where
-    mfix f = ExceptT (mfix (runExceptT . f . either (const bomb) id))
-      where bomb = error "mfix (ExceptT): inner computation returned Left value"
-    {-# INLINE mfix #-}
-
-instance MonadTrans (ExceptT e) where
-    lift = ExceptT . liftM Right
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (ExceptT e m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,4,0)
-instance (MonadZip m) => MonadZip (ExceptT e m) where
-    mzipWith f (ExceptT a) (ExceptT b) = ExceptT $ mzipWith (liftA2 f) a b
-    {-# INLINE mzipWith #-}
-#endif
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (ExceptT e m) where
-    contramap f = ExceptT . contramap (fmap f) . runExceptT
-    {-# INLINE contramap #-}
-#endif
-
--- | Signal an exception value @e@.
---
--- * @'runExceptT' ('throwE' e) = 'return' ('Left' e)@
---
--- * @'throwE' e >>= m = 'throwE' e@
-throwE :: (Monad m) => e -> ExceptT e m a
-throwE = ExceptT . return . Left
-{-# INLINE throwE #-}
-
--- | Handle an exception.
---
--- * @'catchE' ('lift' m) h = 'lift' m@
---
--- * @'catchE' ('throwE' e) h = h e@
-catchE :: (Monad m) =>
-    ExceptT e m a               -- ^ the inner computation
-    -> (e -> ExceptT e' m a)    -- ^ a handler for exceptions in the inner
-                                -- computation
-    -> ExceptT e' m a
-m `catchE` h = ExceptT $ do
-    a <- runExceptT m
-    case a of
-        Left  l -> runExceptT (h l)
-        Right r -> return (Right r)
-{-# INLINE catchE #-}
-
--- | Lift a @callCC@ operation to the new monad.
-liftCallCC :: CallCC m (Either e a) (Either e b) -> CallCC (ExceptT e m) a b
-liftCallCC callCC f = ExceptT $
-    callCC $ \ c ->
-    runExceptT (f (\ a -> ExceptT $ c (Right a)))
-{-# INLINE liftCallCC #-}
-
--- | Lift a @listen@ operation to the new monad.
-liftListen :: (Monad m) => Listen w m (Either e a) -> Listen w (ExceptT e m) a
-liftListen listen = mapExceptT $ \ m -> do
-    (a, w) <- listen m
-    return $! fmap (\ r -> (r, w)) a
-{-# INLINE liftListen #-}
-
--- | Lift a @pass@ operation to the new monad.
-liftPass :: (Monad m) => Pass w m (Either e a) -> Pass w (ExceptT e m) a
-liftPass pass = mapExceptT $ \ m -> pass $ do
-    a <- m
-    return $! case a of
-        Left l -> (Left l, id)
-        Right (r, f) -> (Right r, f)
-{-# INLINE liftPass #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Identity.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Identity.hs
deleted file mode 100644
index 2a0db5e5a165..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Identity.hs
+++ /dev/null
@@ -1,188 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Identity
--- Copyright   :  (c) 2007 Magnus Therning
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The identity monad transformer.
---
--- This is useful for functions parameterized by a monad transformer.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Identity (
-    -- * The identity monad transformer
-    IdentityT(..),
-    mapIdentityT,
-    -- * Lifting other operations
-    liftCatch,
-    liftCallCC,
-  ) where
-
-import Control.Monad.IO.Class (MonadIO(liftIO))
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class (MonadTrans(lift))
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-
-import Control.Applicative
-import Control.Monad (MonadPlus(mzero, mplus))
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix (MonadFix(mfix))
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith))
-#endif
-import Data.Foldable
-import Data.Traversable (Traversable(traverse))
-import Prelude hiding (foldr, foldr1, foldl, foldl1, null, length)
-
--- | The trivial monad transformer, which maps a monad to an equivalent monad.
-newtype IdentityT f a = IdentityT { runIdentityT :: f a }
-
-instance (Eq1 f) => Eq1 (IdentityT f) where
-    liftEq eq (IdentityT x) (IdentityT y) = liftEq eq x y
-    {-# INLINE liftEq #-}
-
-instance (Ord1 f) => Ord1 (IdentityT f) where
-    liftCompare comp (IdentityT x) (IdentityT y) = liftCompare comp x y
-    {-# INLINE liftCompare #-}
-
-instance (Read1 f) => Read1 (IdentityT f) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp rl) "IdentityT" IdentityT
-
-instance (Show1 f) => Show1 (IdentityT f) where
-    liftShowsPrec sp sl d (IdentityT m) =
-        showsUnaryWith (liftShowsPrec sp sl) "IdentityT" d m
-
-instance (Eq1 f, Eq a) => Eq (IdentityT f a) where (==) = eq1
-instance (Ord1 f, Ord a) => Ord (IdentityT f a) where compare = compare1
-instance (Read1 f, Read a) => Read (IdentityT f a) where readsPrec = readsPrec1
-instance (Show1 f, Show a) => Show (IdentityT f a) where showsPrec = showsPrec1
-
-instance (Functor m) => Functor (IdentityT m) where
-    fmap f = mapIdentityT (fmap f)
-    {-# INLINE fmap #-}
-
-instance (Foldable f) => Foldable (IdentityT f) where
-    foldMap f (IdentityT t) = foldMap f t
-    {-# INLINE foldMap #-}
-    foldr f z (IdentityT t) = foldr f z t
-    {-# INLINE foldr #-}
-    foldl f z (IdentityT t) = foldl f z t
-    {-# INLINE foldl #-}
-    foldr1 f (IdentityT t) = foldr1 f t
-    {-# INLINE foldr1 #-}
-    foldl1 f (IdentityT t) = foldl1 f t
-    {-# INLINE foldl1 #-}
-#if MIN_VERSION_base(4,8,0)
-    null (IdentityT t) = null t
-    length (IdentityT t) = length t
-#endif
-
-instance (Traversable f) => Traversable (IdentityT f) where
-    traverse f (IdentityT a) = IdentityT <$> traverse f a
-    {-# INLINE traverse #-}
-
-instance (Applicative m) => Applicative (IdentityT m) where
-    pure x = IdentityT (pure x)
-    {-# INLINE pure #-}
-    (<*>) = lift2IdentityT (<*>)
-    {-# INLINE (<*>) #-}
-    (*>) = lift2IdentityT (*>)
-    {-# INLINE (*>) #-}
-    (<*) = lift2IdentityT (<*)
-    {-# INLINE (<*) #-}
-
-instance (Alternative m) => Alternative (IdentityT m) where
-    empty = IdentityT empty
-    {-# INLINE empty #-}
-    (<|>) = lift2IdentityT (<|>)
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (IdentityT m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return = IdentityT . return
-    {-# INLINE return #-}
-#endif
-    m >>= k = IdentityT $ runIdentityT . k =<< runIdentityT m
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = IdentityT $ fail msg
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (IdentityT m) where
-    fail msg = IdentityT $ Fail.fail msg
-    {-# INLINE fail #-}
-#endif
-
-instance (MonadPlus m) => MonadPlus (IdentityT m) where
-    mzero = IdentityT mzero
-    {-# INLINE mzero #-}
-    mplus = lift2IdentityT mplus
-    {-# INLINE mplus #-}
-
-instance (MonadFix m) => MonadFix (IdentityT m) where
-    mfix f = IdentityT (mfix (runIdentityT . f))
-    {-# INLINE mfix #-}
-
-instance (MonadIO m) => MonadIO (IdentityT m) where
-    liftIO = IdentityT . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,4,0)
-instance (MonadZip m) => MonadZip (IdentityT m) where
-    mzipWith f = lift2IdentityT (mzipWith f)
-    {-# INLINE mzipWith #-}
-#endif
-
-instance MonadTrans IdentityT where
-    lift = IdentityT
-    {-# INLINE lift #-}
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant f => Contravariant (IdentityT f) where
-    contramap f = IdentityT . contramap f . runIdentityT
-    {-# INLINE contramap #-}
-#endif
-
--- | Lift a unary operation to the new monad.
-mapIdentityT :: (m a -> n b) -> IdentityT m a -> IdentityT n b
-mapIdentityT f = IdentityT . f . runIdentityT
-{-# INLINE mapIdentityT #-}
-
--- | Lift a binary operation to the new monad.
-lift2IdentityT ::
-    (m a -> n b -> p c) -> IdentityT m a -> IdentityT n b -> IdentityT p c
-lift2IdentityT f a b = IdentityT (f (runIdentityT a) (runIdentityT b))
-{-# INLINE lift2IdentityT #-}
-
--- | Lift a @callCC@ operation to the new monad.
-liftCallCC :: CallCC m a b -> CallCC (IdentityT m) a b
-liftCallCC callCC f =
-    IdentityT $ callCC $ \ c -> runIdentityT (f (IdentityT . c))
-{-# INLINE liftCallCC #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m a -> Catch e (IdentityT m) a
-liftCatch f m h = IdentityT $ f (runIdentityT m) (runIdentityT . h)
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/List.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/List.hs
deleted file mode 100644
index 0bdbcc732e83..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/List.hs
+++ /dev/null
@@ -1,185 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.List
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The ListT monad transformer, adding backtracking to a given monad,
--- which must be commutative.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.List
-  {-# DEPRECATED "This transformer is invalid on most monads" #-} (
-    -- * The ListT monad transformer
-    ListT(..),
-    mapListT,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCatch,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith))
-#endif
-import Data.Foldable (Foldable(foldMap))
-import Data.Traversable (Traversable(traverse))
-
--- | Parameterizable list monad, with an inner monad.
---
--- /Note:/ this does not yield a monad unless the argument monad is commutative.
-newtype ListT m a = ListT { runListT :: m [a] }
-
-instance (Eq1 m) => Eq1 (ListT m) where
-    liftEq eq (ListT x) (ListT y) = liftEq (liftEq eq) x y
-    {-# INLINE liftEq #-}
-
-instance (Ord1 m) => Ord1 (ListT m) where
-    liftCompare comp (ListT x) (ListT y) = liftCompare (liftCompare comp) x y
-    {-# INLINE liftCompare #-}
-
-instance (Read1 m) => Read1 (ListT m) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp' rl') "ListT" ListT
-      where
-        rp' = liftReadsPrec rp rl
-        rl' = liftReadList rp rl
-
-instance (Show1 m) => Show1 (ListT m) where
-    liftShowsPrec sp sl d (ListT m) =
-        showsUnaryWith (liftShowsPrec sp' sl') "ListT" d m
-      where
-        sp' = liftShowsPrec sp sl
-        sl' = liftShowList sp sl
-
-instance (Eq1 m, Eq a) => Eq (ListT m a) where (==) = eq1
-instance (Ord1 m, Ord a) => Ord (ListT m a) where compare = compare1
-instance (Read1 m, Read a) => Read (ListT m a) where readsPrec = readsPrec1
-instance (Show1 m, Show a) => Show (ListT m a) where showsPrec = showsPrec1
-
--- | Map between 'ListT' computations.
---
--- * @'runListT' ('mapListT' f m) = f ('runListT' m)@
-mapListT :: (m [a] -> n [b]) -> ListT m a -> ListT n b
-mapListT f m = ListT $ f (runListT m)
-{-# INLINE mapListT #-}
-
-instance (Functor m) => Functor (ListT m) where
-    fmap f = mapListT $ fmap $ map f
-    {-# INLINE fmap #-}
-
-instance (Foldable f) => Foldable (ListT f) where
-    foldMap f (ListT a) = foldMap (foldMap f) a
-    {-# INLINE foldMap #-}
-
-instance (Traversable f) => Traversable (ListT f) where
-    traverse f (ListT a) = ListT <$> traverse (traverse f) a
-    {-# INLINE traverse #-}
-
-instance (Applicative m) => Applicative (ListT m) where
-    pure a  = ListT $ pure [a]
-    {-# INLINE pure #-}
-    f <*> v = ListT $ (<*>) <$> runListT f <*> runListT v
-    {-# INLINE (<*>) #-}
-
-instance (Applicative m) => Alternative (ListT m) where
-    empty   = ListT $ pure []
-    {-# INLINE empty #-}
-    m <|> n = ListT $ (++) <$> runListT m <*> runListT n
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (ListT m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = ListT $ return [a]
-    {-# INLINE return #-}
-#endif
-    m >>= k  = ListT $ do
-        a <- runListT m
-        b <- mapM (runListT . k) a
-        return (concat b)
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail _ = ListT $ return []
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Monad m) => Fail.MonadFail (ListT m) where
-    fail _ = ListT $ return []
-    {-# INLINE fail #-}
-#endif
-
-instance (Monad m) => MonadPlus (ListT m) where
-    mzero       = ListT $ return []
-    {-# INLINE mzero #-}
-    m `mplus` n = ListT $ do
-        a <- runListT m
-        b <- runListT n
-        return (a ++ b)
-    {-# INLINE mplus #-}
-
-instance (MonadFix m) => MonadFix (ListT m) where
-    mfix f = ListT $ mfix (runListT . f . head) >>= \ xs -> case xs of
-        [] -> return []
-        x:_ -> liftM (x:) (runListT (mfix (mapListT (liftM tail) . f)))
-    {-# INLINE mfix #-}
-
-instance MonadTrans ListT where
-    lift m = ListT $ do
-        a <- m
-        return [a]
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (ListT m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,4,0)
-instance (MonadZip m) => MonadZip (ListT m) where
-    mzipWith f (ListT a) (ListT b) = ListT $ mzipWith (zipWith f) a b
-    {-# INLINE mzipWith #-}
-#endif
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (ListT m) where
-    contramap f = ListT . contramap (fmap f) . runListT
-    {-# INLINE contramap #-}
-#endif
-
--- | Lift a @callCC@ operation to the new monad.
-liftCallCC :: CallCC m [a] [b] -> CallCC (ListT m) a b
-liftCallCC callCC f = ListT $
-    callCC $ \ c ->
-    runListT (f (\ a -> ListT $ c [a]))
-{-# INLINE liftCallCC #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m [a] -> Catch e (ListT m) a
-liftCatch catchE m h = ListT $ runListT m
-    `catchE` \ e -> runListT (h e)
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Maybe.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Maybe.hs
deleted file mode 100644
index f02b225444f8..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Maybe.hs
+++ /dev/null
@@ -1,241 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Maybe
--- Copyright   :  (c) 2007 Yitzak Gale, Eric Kidd
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The 'MaybeT' monad transformer extends a monad with the ability to exit
--- the computation without returning a value.
---
--- A sequence of actions produces a value only if all the actions in
--- the sequence do.  If one exits, the rest of the sequence is skipped
--- and the composite action exits.
---
--- For a variant allowing a range of exception values, see
--- "Control.Monad.Trans.Except".
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Maybe (
-    -- * The MaybeT monad transformer
-    MaybeT(..),
-    mapMaybeT,
-    -- * Monad transformations
-    maybeToExceptT,
-    exceptToMaybeT,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCatch,
-    liftListen,
-    liftPass,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-import Control.Monad.Trans.Except (ExceptT(..))
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-
-import Control.Applicative
-import Control.Monad (MonadPlus(mzero, mplus), liftM)
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix (MonadFix(mfix))
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith))
-#endif
-import Data.Foldable (Foldable(foldMap))
-import Data.Maybe (fromMaybe)
-import Data.Traversable (Traversable(traverse))
-
--- | The parameterizable maybe monad, obtained by composing an arbitrary
--- monad with the 'Maybe' monad.
---
--- Computations are actions that may produce a value or exit.
---
--- The 'return' function yields a computation that produces that
--- value, while @>>=@ sequences two subcomputations, exiting if either
--- computation does.
-newtype MaybeT m a = MaybeT { runMaybeT :: m (Maybe a) }
-
-instance (Eq1 m) => Eq1 (MaybeT m) where
-    liftEq eq (MaybeT x) (MaybeT y) = liftEq (liftEq eq) x y
-    {-# INLINE liftEq #-}
-
-instance (Ord1 m) => Ord1 (MaybeT m) where
-    liftCompare comp (MaybeT x) (MaybeT y) = liftCompare (liftCompare comp) x y
-    {-# INLINE liftCompare #-}
-
-instance (Read1 m) => Read1 (MaybeT m) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp' rl') "MaybeT" MaybeT
-      where
-        rp' = liftReadsPrec rp rl
-        rl' = liftReadList rp rl
-
-instance (Show1 m) => Show1 (MaybeT m) where
-    liftShowsPrec sp sl d (MaybeT m) =
-        showsUnaryWith (liftShowsPrec sp' sl') "MaybeT" d m
-      where
-        sp' = liftShowsPrec sp sl
-        sl' = liftShowList sp sl
-
-instance (Eq1 m, Eq a) => Eq (MaybeT m a) where (==) = eq1
-instance (Ord1 m, Ord a) => Ord (MaybeT m a) where compare = compare1
-instance (Read1 m, Read a) => Read (MaybeT m a) where readsPrec = readsPrec1
-instance (Show1 m, Show a) => Show (MaybeT m a) where showsPrec = showsPrec1
-
--- | Transform the computation inside a @MaybeT@.
---
--- * @'runMaybeT' ('mapMaybeT' f m) = f ('runMaybeT' m)@
-mapMaybeT :: (m (Maybe a) -> n (Maybe b)) -> MaybeT m a -> MaybeT n b
-mapMaybeT f = MaybeT . f . runMaybeT
-{-# INLINE mapMaybeT #-}
-
--- | Convert a 'MaybeT' computation to 'ExceptT', with a default
--- exception value.
-maybeToExceptT :: (Functor m) => e -> MaybeT m a -> ExceptT e m a
-maybeToExceptT e (MaybeT m) = ExceptT $ fmap (maybe (Left e) Right) m
-{-# INLINE maybeToExceptT #-}
-
--- | Convert a 'ExceptT' computation to 'MaybeT', discarding the
--- value of any exception.
-exceptToMaybeT :: (Functor m) => ExceptT e m a -> MaybeT m a
-exceptToMaybeT (ExceptT m) = MaybeT $ fmap (either (const Nothing) Just) m
-{-# INLINE exceptToMaybeT #-}
-
-instance (Functor m) => Functor (MaybeT m) where
-    fmap f = mapMaybeT (fmap (fmap f))
-    {-# INLINE fmap #-}
-
-instance (Foldable f) => Foldable (MaybeT f) where
-    foldMap f (MaybeT a) = foldMap (foldMap f) a
-    {-# INLINE foldMap #-}
-
-instance (Traversable f) => Traversable (MaybeT f) where
-    traverse f (MaybeT a) = MaybeT <$> traverse (traverse f) a
-    {-# INLINE traverse #-}
-
-instance (Functor m, Monad m) => Applicative (MaybeT m) where
-    pure = MaybeT . return . Just
-    {-# INLINE pure #-}
-    mf <*> mx = MaybeT $ do
-        mb_f <- runMaybeT mf
-        case mb_f of
-            Nothing -> return Nothing
-            Just f  -> do
-                mb_x <- runMaybeT mx
-                case mb_x of
-                    Nothing -> return Nothing
-                    Just x  -> return (Just (f x))
-    {-# INLINE (<*>) #-}
-    m *> k = m >>= \_ -> k
-    {-# INLINE (*>) #-}
-
-instance (Functor m, Monad m) => Alternative (MaybeT m) where
-    empty = MaybeT (return Nothing)
-    {-# INLINE empty #-}
-    x <|> y = MaybeT $ do
-        v <- runMaybeT x
-        case v of
-            Nothing -> runMaybeT y
-            Just _  -> return v
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (MaybeT m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return = MaybeT . return . Just
-    {-# INLINE return #-}
-#endif
-    x >>= f = MaybeT $ do
-        v <- runMaybeT x
-        case v of
-            Nothing -> return Nothing
-            Just y  -> runMaybeT (f y)
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail _ = MaybeT (return Nothing)
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Monad m) => Fail.MonadFail (MaybeT m) where
-    fail _ = MaybeT (return Nothing)
-    {-# INLINE fail #-}
-#endif
-
-instance (Monad m) => MonadPlus (MaybeT m) where
-    mzero = MaybeT (return Nothing)
-    {-# INLINE mzero #-}
-    mplus x y = MaybeT $ do
-        v <- runMaybeT x
-        case v of
-            Nothing -> runMaybeT y
-            Just _  -> return v
-    {-# INLINE mplus #-}
-
-instance (MonadFix m) => MonadFix (MaybeT m) where
-    mfix f = MaybeT (mfix (runMaybeT . f . fromMaybe bomb))
-      where bomb = error "mfix (MaybeT): inner computation returned Nothing"
-    {-# INLINE mfix #-}
-
-instance MonadTrans MaybeT where
-    lift = MaybeT . liftM Just
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (MaybeT m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,4,0)
-instance (MonadZip m) => MonadZip (MaybeT m) where
-    mzipWith f (MaybeT a) (MaybeT b) = MaybeT $ mzipWith (liftA2 f) a b
-    {-# INLINE mzipWith #-}
-#endif
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (MaybeT m) where
-    contramap f = MaybeT . contramap (fmap f) . runMaybeT
-    {-# INLINE contramap #-}
-#endif
-
--- | Lift a @callCC@ operation to the new monad.
-liftCallCC :: CallCC m (Maybe a) (Maybe b) -> CallCC (MaybeT m) a b
-liftCallCC callCC f =
-    MaybeT $ callCC $ \ c -> runMaybeT (f (MaybeT . c . Just))
-{-# INLINE liftCallCC #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (Maybe a) -> Catch e (MaybeT m) a
-liftCatch f m h = MaybeT $ f (runMaybeT m) (runMaybeT . h)
-{-# INLINE liftCatch #-}
-
--- | Lift a @listen@ operation to the new monad.
-liftListen :: (Monad m) => Listen w m (Maybe a) -> Listen w (MaybeT m) a
-liftListen listen = mapMaybeT $ \ m -> do
-    (a, w) <- listen m
-    return $! fmap (\ r -> (r, w)) a
-{-# INLINE liftListen #-}
-
--- | Lift a @pass@ operation to the new monad.
-liftPass :: (Monad m) => Pass w m (Maybe a) -> Pass w (MaybeT m) a
-liftPass pass = mapMaybeT $ \ m -> pass $ do
-    a <- m
-    return $! case a of
-        Nothing     -> (Nothing, id)
-        Just (v, f) -> (Just v, f)
-{-# INLINE liftPass #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS.hs
deleted file mode 100644
index b4cc6adaad78..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS.hs
+++ /dev/null
@@ -1,25 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.RWS
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- A monad transformer that combines 'ReaderT', 'WriterT' and 'StateT'.
--- This version is lazy; for a constant-space version with almost the
--- same interface, see "Control.Monad.Trans.RWS.CPS".
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.RWS (
-    module Control.Monad.Trans.RWS.Lazy
-  ) where
-
-import Control.Monad.Trans.RWS.Lazy
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/CPS.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/CPS.hs
deleted file mode 100644
index 8a565e1652c3..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/CPS.hs
+++ /dev/null
@@ -1,406 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.RWS.CPS
--- Copyright   :  (c) Daniel Mendler 2016,
---                (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- A monad transformer that combines 'ReaderT', 'WriterT' and 'StateT'.
--- This version uses continuation-passing-style for the writer part
--- to achieve constant space usage.
--- For a lazy version with the same interface,
--- see "Control.Monad.Trans.RWS.Lazy".
------------------------------------------------------------------------------
-  
-module Control.Monad.Trans.RWS.CPS (
-    -- * The RWS monad
-    RWS,
-    rws,
-    runRWS,
-    evalRWS,
-    execRWS,
-    mapRWS,
-    withRWS,
-    -- * The RWST monad transformer
-    RWST,
-    rwsT,
-    runRWST,
-    evalRWST,
-    execRWST,
-    mapRWST,
-    withRWST,
-    -- * Reader operations
-    reader,
-    ask,
-    local,
-    asks,
-    -- * Writer operations
-    writer,
-    tell,
-    listen,
-    listens,
-    pass,
-    censor,
-    -- * State operations
-    state,
-    get,
-    put,
-    modify,
-    gets,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCallCC',
-    liftCatch,
-  ) where
-
-import Control.Applicative
-import Control.Monad
-import Control.Monad.Fix
-import Control.Monad.IO.Class
-import Control.Monad.Trans.Class
-import Control.Monad.Signatures
-import Data.Functor.Identity
-
-#if !(MIN_VERSION_base(4,8,0))
-import Data.Monoid
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-
--- | A monad containing an environment of type @r@, output of type @w@
--- and an updatable state of type @s@.
-type RWS r w s = RWST r w s Identity
-
--- | Construct an RWS computation from a function.
--- (The inverse of 'runRWS'.)
-rws :: (Monoid w) => (r -> s -> (a, s, w)) -> RWS r w s a
-rws f = RWST $ \ r s w ->
-    let (a, s', w') = f r s; wt = w `mappend` w' in wt `seq` return (a, s', wt)
-{-# INLINE rws #-}
-
--- | Unwrap an RWS computation as a function.
--- (The inverse of 'rws'.)
-runRWS :: (Monoid w) => RWS r w s a -> r -> s -> (a, s, w)
-runRWS m r s = runIdentity (runRWST m r s)
-{-# INLINE runRWS #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final value and output, discarding the final state.
-evalRWS :: (Monoid w)
-        => RWS r w s a  -- ^RWS computation to execute
-        -> r            -- ^initial environment
-        -> s            -- ^initial value
-        -> (a, w)       -- ^final value and output
-evalRWS m r s = let
-    (a, _, w) = runRWS m r s
-    in (a, w)
-{-# INLINE evalRWS #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final state and output, discarding the final value.
-execRWS :: (Monoid w)
-        => RWS r w s a  -- ^RWS computation to execute
-        -> r            -- ^initial environment
-        -> s            -- ^initial value
-        -> (s, w)       -- ^final state and output
-execRWS m r s = let
-    (_, s', w) = runRWS m r s
-    in (s', w)
-{-# INLINE execRWS #-}
-
--- | Map the return value, final state and output of a computation using
--- the given function.
---
--- * @'runRWS' ('mapRWS' f m) r s = f ('runRWS' m r s)@
-mapRWS :: (Monoid w, Monoid w') => ((a, s, w) -> (b, s, w')) -> RWS r w s a -> RWS r w' s b
-mapRWS f = mapRWST (Identity . f . runIdentity)
-{-# INLINE mapRWS #-}
-
--- | @'withRWS' f m@ executes action @m@ with an initial environment
--- and state modified by applying @f@.
---
--- * @'runRWS' ('withRWS' f m) r s = 'uncurry' ('runRWS' m) (f r s)@
-withRWS :: (r' -> s -> (r, s)) -> RWS r w s a -> RWS r' w s a
-withRWS = withRWST
-{-# INLINE withRWS #-}
-
--- ---------------------------------------------------------------------------
--- | A monad transformer adding reading an environment of type @r@,
--- collecting an output of type @w@ and updating a state of type @s@
--- to an inner monad @m@.
-newtype RWST r w s m a = RWST { unRWST :: r -> s -> w -> m (a, s, w) }
-
--- | Construct an RWST computation from a function.
--- (The inverse of 'runRWST'.)
-rwsT :: (Functor m, Monoid w) => (r -> s -> m (a, s, w)) -> RWST r w s m a
-rwsT f = RWST $ \ r s w ->
-     (\ (a, s', w') -> let wt = w `mappend` w' in wt `seq` (a, s', wt)) <$> f r s
-{-# INLINE rwsT #-}
-
--- | Unwrap an RWST computation as a function.
--- (The inverse of 'rwsT'.)
-runRWST :: (Monoid w) => RWST r w s m a -> r -> s -> m (a, s, w)
-runRWST m r s = unRWST m r s mempty
-{-# INLINE runRWST #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final value and output, discarding the final state.
-evalRWST :: (Monad m, Monoid w)
-         => RWST r w s m a      -- ^computation to execute
-         -> r                   -- ^initial environment
-         -> s                   -- ^initial value
-         -> m (a, w)            -- ^computation yielding final value and output
-evalRWST m r s = do
-    (a, _, w) <- runRWST m r s
-    return (a, w)
-{-# INLINE evalRWST #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final state and output, discarding the final value.
-execRWST :: (Monad m, Monoid w)
-         => RWST r w s m a      -- ^computation to execute
-         -> r                   -- ^initial environment
-         -> s                   -- ^initial value
-         -> m (s, w)            -- ^computation yielding final state and output
-execRWST m r s = do
-    (_, s', w) <- runRWST m r s
-    return (s', w)
-{-# INLINE execRWST #-}
-
--- | Map the inner computation using the given function.
---
--- * @'runRWST' ('mapRWST' f m) r s = f ('runRWST' m r s)@
---mapRWST :: (m (a, s, w) -> n (b, s, w')) -> RWST r w s m a -> RWST r w' s n b
-mapRWST :: (Monad n, Monoid w, Monoid w') =>
-    (m (a, s, w) -> n (b, s, w')) -> RWST r w s m a -> RWST r w' s n b
-mapRWST f m = RWST $ \ r s w -> do
-    (a, s', w') <- f (runRWST m r s)
-    let wt = w `mappend` w'
-    wt `seq` return (a, s', wt)
-{-# INLINE mapRWST #-}
-
--- | @'withRWST' f m@ executes action @m@ with an initial environment
--- and state modified by applying @f@.
---
--- * @'runRWST' ('withRWST' f m) r s = 'uncurry' ('runRWST' m) (f r s)@
-withRWST :: (r' -> s -> (r, s)) -> RWST r w s m a -> RWST r' w s m a
-withRWST f m = RWST $ \ r s -> uncurry (unRWST m) (f r s)
-{-# INLINE withRWST #-}
-
-instance (Functor m) => Functor (RWST r w s m) where
-    fmap f m = RWST $ \ r s w -> (\ (a, s', w') -> (f a, s', w')) <$> unRWST m r s w
-    {-# INLINE fmap #-}
-
-instance (Functor m, Monad m) => Applicative (RWST r w s m) where
-    pure a = RWST $ \ _ s w -> return (a, s, w)
-    {-# INLINE pure #-}
-
-    RWST mf <*> RWST mx = RWST $ \ r s w -> do
-        (f, s', w')    <- mf r s w
-        (x, s'', w'') <- mx r s' w'
-        return (f x, s'', w'')
-    {-# INLINE (<*>) #-}
-
-instance (Functor m, MonadPlus m) => Alternative (RWST r w s m) where
-    empty = RWST $ \ _ _ _ -> mzero
-    {-# INLINE empty #-}
-
-    RWST m <|> RWST n = RWST $ \ r s w -> m r s w `mplus` n r s w
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (RWST r w s m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = RWST $ \ _ s w -> return (a, s, w)
-    {-# INLINE return #-}
-#endif
-
-    m >>= k = RWST $ \ r s w -> do
-        (a, s', w')    <- unRWST m r s w
-        unRWST (k a) r s' w'
-    {-# INLINE (>>=) #-}
-
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = RWST $ \ _ _ _ -> fail msg
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (RWST r w s m) where
-    fail msg = RWST $ \ _ _ _ -> Fail.fail msg
-    {-# INLINE fail #-}
-#endif
-
-instance (Functor m, MonadPlus m) => MonadPlus (RWST r w s m) where
-    mzero = empty
-    {-# INLINE mzero #-}
-    mplus = (<|>)
-    {-# INLINE mplus #-}
-
-instance (MonadFix m) => MonadFix (RWST r w s m) where
-    mfix f = RWST $ \ r s w -> mfix $ \ ~(a, _, _) -> unRWST (f a) r s w
-    {-# INLINE mfix #-}
-
-instance MonadTrans (RWST r w s) where
-    lift m = RWST $ \ _ s w -> do
-        a <- m
-        return (a, s, w)
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (RWST r w s m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
--- ---------------------------------------------------------------------------
--- Reader operations
-
--- | Constructor for computations in the reader monad (equivalent to 'asks').
-reader :: (Monad m) => (r -> a) -> RWST r w s m a
-reader = asks
-{-# INLINE reader #-}
-
--- | Fetch the value of the environment.
-ask :: (Monad m) => RWST r w s m r
-ask = asks id
-{-# INLINE ask #-}
-
--- | Execute a computation in a modified environment
---
--- * @'runRWST' ('local' f m) r s = 'runRWST' m (f r) s@
-local :: (r -> r) -> RWST r w s m a -> RWST r w s m a
-local f m = RWST $ \ r s w -> unRWST m (f r) s w
-{-# INLINE local #-}
-
--- | Retrieve a function of the current environment.
---
--- * @'asks' f = 'liftM' f 'ask'@
-asks :: (Monad m) => (r -> a) -> RWST r w s m a
-asks f = RWST $ \ r s w -> return (f r, s, w)
-{-# INLINE asks #-}
-
--- ---------------------------------------------------------------------------
--- Writer operations
-
--- | Construct a writer computation from a (result, output) pair.
-writer :: (Monoid w, Monad m) => (a, w) -> RWST r w s m a
-writer (a, w') = RWST $ \ _ s w -> let wt = w `mappend` w' in wt `seq` return (a, s, wt)
-{-# INLINE writer #-}
-
--- | @'tell' w@ is an action that produces the output @w@.
-tell :: (Monoid w, Monad m) => w -> RWST r w s m ()
-tell w' = writer ((), w')
-{-# INLINE tell #-}
-
--- | @'listen' m@ is an action that executes the action @m@ and adds its
--- output to the value of the computation.
---
--- * @'runRWST' ('listen' m) r s = 'liftM' (\\ (a, w) -> ((a, w), w)) ('runRWST' m r s)@
-listen :: (Monoid w, Monad m) => RWST r w s m a -> RWST r w s m (a, w)
-listen = listens id
-{-# INLINE listen #-}
-
--- | @'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.
---
--- * @'listens' f m = 'liftM' (id *** f) ('listen' m)@
---
--- * @'runRWST' ('listens' f m) r s = 'liftM' (\\ (a, w) -> ((a, f w), w)) ('runRWST' m r s)@
-listens :: (Monoid w, Monad m) => (w -> b) -> RWST r w s m a -> RWST r w s m (a, b)
-listens f m = RWST $ \ r s w -> do
-    (a, s', w') <- runRWST m r s
-    let wt = w `mappend` w'
-    wt `seq` return ((a, f w'), s', wt)
-{-# INLINE listens #-}
-
--- | @'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.
---
--- * @'runRWST' ('pass' m) r s = 'liftM' (\\ ((a, f), w) -> (a, f w)) ('runRWST' m r s)@
-pass :: (Monoid w, Monoid w', Monad m) => RWST r w s m (a, w -> w') -> RWST r w' s m a
-pass m = RWST $ \ r s w -> do
-    ((a, f), s', w') <- runRWST m r s
-    let wt = w `mappend` f w'
-    wt `seq` return (a, s', wt)
-{-# INLINE pass #-}
-
--- | @'censor' f m@ is an action that executes the action @m@ and
--- applies the function @f@ to its output, leaving the return value
--- unchanged.
---
--- * @'censor' f m = 'pass' ('liftM' (\\ x -> (x,f)) m)@
---
--- * @'runRWST' ('censor' f m) r s = 'liftM' (\\ (a, w) -> (a, f w)) ('runRWST' m r s)@
-censor :: (Monoid w, Monad m) => (w -> w) -> RWST r w s m a -> RWST r w s m a
-censor f m = RWST $ \ r s w -> do
-    (a, s', w') <- runRWST m r s
-    let wt = w `mappend` f w'
-    wt `seq` return (a, s', wt)
-{-# INLINE censor #-}
-
--- ---------------------------------------------------------------------------
--- State operations
-
--- | Construct a state monad computation from a state transformer function.
-state :: (Monad m) => (s -> (a, s)) -> RWST r w s m a
-state f = RWST $ \ _ s w -> let (a, s') = f s in return (a, s', w)
-{-# INLINE state #-}
-
--- | Fetch the current value of the state within the monad.
-get :: (Monad m) =>RWST r w s m s
-get = gets id
-{-# INLINE get #-}
-
--- | @'put' s@ sets the state within the monad to @s@.
-put :: (Monad m) =>s -> RWST r w s m ()
-put s = RWST $ \ _ _ w -> return ((), s, w)
-{-# INLINE put #-}
-
--- | @'modify' f@ is an action that updates the state to the result of
--- applying @f@ to the current state.
---
--- * @'modify' f = 'get' >>= ('put' . f)@
-modify :: (Monad m) =>(s -> s) -> RWST r w s m ()
-modify f = RWST $ \ _ s w -> return ((), f s, w)
-{-# INLINE modify #-}
-
--- | Get a specific component of the state, using a projection function
--- supplied.
---
--- * @'gets' f = 'liftM' f 'get'@
-gets :: (Monad m) =>(s -> a) -> RWST r w s m a
-gets f = RWST $ \ _ s w -> return (f s, s, w)
-{-# INLINE gets #-}
-
--- | Uniform lifting of a @callCC@ operation to the new monad.
--- This version rolls back to the original state on entering the
--- continuation.
-liftCallCC :: CallCC m (a,s,w) (b,s,w) -> CallCC (RWST r w s m) a b
-liftCallCC callCC f = RWST $ \ r s w ->
-    callCC $ \ c -> unRWST (f (\ a -> RWST $ \ _ _ _ -> c (a, s, w))) r s w
-{-# INLINE liftCallCC #-}
-
--- | In-situ lifting of a @callCC@ operation to the new monad.
--- This version uses the current state on entering the continuation.
-liftCallCC' :: CallCC m (a,s,w) (b,s,w) -> CallCC (RWST r w s m) a b
-liftCallCC' callCC f = RWST $ \ r s w ->
-    callCC $ \ c -> unRWST (f (\ a -> RWST $ \ _ s' _ -> c (a, s', w))) r s w
-{-# INLINE liftCallCC' #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a,s,w) -> Catch e (RWST r w s m) a
-liftCatch catchE m h =
-    RWST $ \ r s w -> unRWST m r s w `catchE` \ e -> unRWST (h e) r s w
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/Lazy.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/Lazy.hs
deleted file mode 100644
index 8f98b2c5e05a..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/Lazy.hs
+++ /dev/null
@@ -1,389 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.RWS.Lazy
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- A monad transformer that combines 'ReaderT', 'WriterT' and 'StateT'.
--- This version is lazy; for a constant-space version with almost the
--- same interface, see "Control.Monad.Trans.RWS.CPS".
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.RWS.Lazy (
-    -- * The RWS monad
-    RWS,
-    rws,
-    runRWS,
-    evalRWS,
-    execRWS,
-    mapRWS,
-    withRWS,
-    -- * The RWST monad transformer
-    RWST(..),
-    evalRWST,
-    execRWST,
-    mapRWST,
-    withRWST,
-    -- * Reader operations
-    reader,
-    ask,
-    local,
-    asks,
-    -- * Writer operations
-    writer,
-    tell,
-    listen,
-    listens,
-    pass,
-    censor,
-    -- * State operations
-    state,
-    get,
-    put,
-    modify,
-    gets,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCallCC',
-    liftCatch,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-import Data.Monoid
-
--- | A monad containing an environment of type @r@, output of type @w@
--- and an updatable state of type @s@.
-type RWS r w s = RWST r w s Identity
-
--- | Construct an RWS computation from a function.
--- (The inverse of 'runRWS'.)
-rws :: (r -> s -> (a, s, w)) -> RWS r w s a
-rws f = RWST (\ r s -> Identity (f r s))
-{-# INLINE rws #-}
-
--- | Unwrap an RWS computation as a function.
--- (The inverse of 'rws'.)
-runRWS :: RWS r w s a -> r -> s -> (a, s, w)
-runRWS m r s = runIdentity (runRWST m r s)
-{-# INLINE runRWS #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final value and output, discarding the final state.
-evalRWS :: RWS r w s a  -- ^RWS computation to execute
-        -> r            -- ^initial environment
-        -> s            -- ^initial value
-        -> (a, w)       -- ^final value and output
-evalRWS m r s = let
-    (a, _, w) = runRWS m r s
-    in (a, w)
-{-# INLINE evalRWS #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final state and output, discarding the final value.
-execRWS :: RWS r w s a  -- ^RWS computation to execute
-        -> r            -- ^initial environment
-        -> s            -- ^initial value
-        -> (s, w)       -- ^final state and output
-execRWS m r s = let
-    (_, s', w) = runRWS m r s
-    in (s', w)
-{-# INLINE execRWS #-}
-
--- | Map the return value, final state and output of a computation using
--- the given function.
---
--- * @'runRWS' ('mapRWS' f m) r s = f ('runRWS' m r s)@
-mapRWS :: ((a, s, w) -> (b, s, w')) -> RWS r w s a -> RWS r w' s b
-mapRWS f = mapRWST (Identity . f . runIdentity)
-{-# INLINE mapRWS #-}
-
--- | @'withRWS' f m@ executes action @m@ with an initial environment
--- and state modified by applying @f@.
---
--- * @'runRWS' ('withRWS' f m) r s = 'uncurry' ('runRWS' m) (f r s)@
-withRWS :: (r' -> s -> (r, s)) -> RWS r w s a -> RWS r' w s a
-withRWS = withRWST
-{-# INLINE withRWS #-}
-
--- ---------------------------------------------------------------------------
--- | A monad transformer adding reading an environment of type @r@,
--- collecting an output of type @w@ and updating a state of type @s@
--- to an inner monad @m@.
-newtype RWST r w s m a = RWST { runRWST :: r -> s -> m (a, s, w) }
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final value and output, discarding the final state.
-evalRWST :: (Monad m)
-         => RWST r w s m a      -- ^computation to execute
-         -> r                   -- ^initial environment
-         -> s                   -- ^initial value
-         -> m (a, w)            -- ^computation yielding final value and output
-evalRWST m r s = do
-    ~(a, _, w) <- runRWST m r s
-    return (a, w)
-{-# INLINE evalRWST #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final state and output, discarding the final value.
-execRWST :: (Monad m)
-         => RWST r w s m a      -- ^computation to execute
-         -> r                   -- ^initial environment
-         -> s                   -- ^initial value
-         -> m (s, w)            -- ^computation yielding final state and output
-execRWST m r s = do
-    ~(_, s', w) <- runRWST m r s
-    return (s', w)
-{-# INLINE execRWST #-}
-
--- | Map the inner computation using the given function.
---
--- * @'runRWST' ('mapRWST' f m) r s = f ('runRWST' m r s)@
-mapRWST :: (m (a, s, w) -> n (b, s, w')) -> RWST r w s m a -> RWST r w' s n b
-mapRWST f m = RWST $ \ r s -> f (runRWST m r s)
-{-# INLINE mapRWST #-}
-
--- | @'withRWST' f m@ executes action @m@ with an initial environment
--- and state modified by applying @f@.
---
--- * @'runRWST' ('withRWST' f m) r s = 'uncurry' ('runRWST' m) (f r s)@
-withRWST :: (r' -> s -> (r, s)) -> RWST r w s m a -> RWST r' w s m a
-withRWST f m = RWST $ \ r s -> uncurry (runRWST m) (f r s)
-{-# INLINE withRWST #-}
-
-instance (Functor m) => Functor (RWST r w s m) where
-    fmap f m = RWST $ \ r s ->
-        fmap (\ ~(a, s', w) -> (f a, s', w)) $ runRWST m r s
-    {-# INLINE fmap #-}
-
-instance (Monoid w, Functor m, Monad m) => Applicative (RWST r w s m) where
-    pure a = RWST $ \ _ s -> return (a, s, mempty)
-    {-# INLINE pure #-}
-    RWST mf <*> RWST mx  = RWST $ \ r s -> do
-        ~(f, s', w)  <- mf r s
-        ~(x, s'',w') <- mx r s'
-        return (f x, s'', w `mappend` w')
-    {-# INLINE (<*>) #-}
-
-instance (Monoid w, Functor m, MonadPlus m) => Alternative (RWST r w s m) where
-    empty = RWST $ \ _ _ -> mzero
-    {-# INLINE empty #-}
-    RWST m <|> RWST n = RWST $ \ r s -> m r s `mplus` n r s
-    {-# INLINE (<|>) #-}
-
-instance (Monoid w, Monad m) => Monad (RWST r w s m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = RWST $ \ _ s -> return (a, s, mempty)
-    {-# INLINE return #-}
-#endif
-    m >>= k  = RWST $ \ r s -> do
-        ~(a, s', w)  <- runRWST m r s
-        ~(b, s'',w') <- runRWST (k a) r s'
-        return (b, s'', w `mappend` w')
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = RWST $ \ _ _ -> fail msg
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Monoid w, Fail.MonadFail m) => Fail.MonadFail (RWST r w s m) where
-    fail msg = RWST $ \ _ _ -> Fail.fail msg
-    {-# INLINE fail #-}
-#endif
-
-instance (Monoid w, MonadPlus m) => MonadPlus (RWST r w s m) where
-    mzero = RWST $ \ _ _ -> mzero
-    {-# INLINE mzero #-}
-    RWST m `mplus` RWST n = RWST $ \ r s -> m r s `mplus` n r s
-    {-# INLINE mplus #-}
-
-instance (Monoid w, MonadFix m) => MonadFix (RWST r w s m) where
-    mfix f = RWST $ \ r s -> mfix $ \ ~(a, _, _) -> runRWST (f a) r s
-    {-# INLINE mfix #-}
-
-instance (Monoid w) => MonadTrans (RWST r w s) where
-    lift m = RWST $ \ _ s -> do
-        a <- m
-        return (a, s, mempty)
-    {-# INLINE lift #-}
-
-instance (Monoid w, MonadIO m) => MonadIO (RWST r w s m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (RWST r w s m) where
-    contramap f m = RWST $ \r s ->
-      contramap (\ ~(a, s', w) -> (f a, s', w)) $ runRWST m r s
-    {-# INLINE contramap #-}
-#endif
-
--- ---------------------------------------------------------------------------
--- Reader operations
-
--- | Constructor for computations in the reader monad (equivalent to 'asks').
-reader :: (Monoid w, Monad m) => (r -> a) -> RWST r w s m a
-reader = asks
-{-# INLINE reader #-}
-
--- | Fetch the value of the environment.
-ask :: (Monoid w, Monad m) => RWST r w s m r
-ask = RWST $ \ r s -> return (r, s, mempty)
-{-# INLINE ask #-}
-
--- | Execute a computation in a modified environment
---
--- * @'runRWST' ('local' f m) r s = 'runRWST' m (f r) s@
-local :: (r -> r) -> RWST r w s m a -> RWST r w s m a
-local f m = RWST $ \ r s -> runRWST m (f r) s
-{-# INLINE local #-}
-
--- | Retrieve a function of the current environment.
---
--- * @'asks' f = 'liftM' f 'ask'@
-asks :: (Monoid w, Monad m) => (r -> a) -> RWST r w s m a
-asks f = RWST $ \ r s -> return (f r, s, mempty)
-{-# INLINE asks #-}
-
--- ---------------------------------------------------------------------------
--- Writer operations
-
--- | Construct a writer computation from a (result, output) pair.
-writer :: (Monad m) => (a, w) -> RWST r w s m a
-writer (a, w) = RWST $ \ _ s -> return (a, s, w)
-{-# INLINE writer #-}
-
--- | @'tell' w@ is an action that produces the output @w@.
-tell :: (Monad m) => w -> RWST r w s m ()
-tell w = RWST $ \ _ s -> return ((),s,w)
-{-# INLINE tell #-}
-
--- | @'listen' m@ is an action that executes the action @m@ and adds its
--- output to the value of the computation.
---
--- * @'runRWST' ('listen' m) r s = 'liftM' (\\ (a, w) -> ((a, w), w)) ('runRWST' m r s)@
-listen :: (Monad m) => RWST r w s m a -> RWST r w s m (a, w)
-listen m = RWST $ \ r s -> do
-    ~(a, s', w) <- runRWST m r s
-    return ((a, w), s', w)
-{-# INLINE listen #-}
-
--- | @'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.
---
--- * @'listens' f m = 'liftM' (id *** f) ('listen' m)@
---
--- * @'runRWST' ('listens' f m) r s = 'liftM' (\\ (a, w) -> ((a, f w), w)) ('runRWST' m r s)@
-listens :: (Monad m) => (w -> b) -> RWST r w s m a -> RWST r w s m (a, b)
-listens f m = RWST $ \ r s -> do
-    ~(a, s', w) <- runRWST m r s
-    return ((a, f w), s', w)
-{-# INLINE listens #-}
-
--- | @'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.
---
--- * @'runRWST' ('pass' m) r s = 'liftM' (\\ ((a, f), w) -> (a, f w)) ('runRWST' m r s)@
-pass :: (Monad m) => RWST r w s m (a, w -> w) -> RWST r w s m a
-pass m = RWST $ \ r s -> do
-    ~((a, f), s', w) <- runRWST m r s
-    return (a, s', f w)
-{-# INLINE pass #-}
-
--- | @'censor' f m@ is an action that executes the action @m@ and
--- applies the function @f@ to its output, leaving the return value
--- unchanged.
---
--- * @'censor' f m = 'pass' ('liftM' (\\ x -> (x,f)) m)@
---
--- * @'runRWST' ('censor' f m) r s = 'liftM' (\\ (a, w) -> (a, f w)) ('runRWST' m r s)@
-censor :: (Monad m) => (w -> w) -> RWST r w s m a -> RWST r w s m a
-censor f m = RWST $ \ r s -> do
-    ~(a, s', w) <- runRWST m r s
-    return (a, s', f w)
-{-# INLINE censor #-}
-
--- ---------------------------------------------------------------------------
--- State operations
-
--- | Construct a state monad computation from a state transformer function.
-state :: (Monoid w, Monad m) => (s -> (a,s)) -> RWST r w s m a
-state f = RWST $ \ _ s -> let (a,s') = f s  in  return (a, s', mempty)
-{-# INLINE state #-}
-
--- | Fetch the current value of the state within the monad.
-get :: (Monoid w, Monad m) => RWST r w s m s
-get = RWST $ \ _ s -> return (s, s, mempty)
-{-# INLINE get #-}
-
--- | @'put' s@ sets the state within the monad to @s@.
-put :: (Monoid w, Monad m) => s -> RWST r w s m ()
-put s = RWST $ \ _ _ -> return ((), s, mempty)
-{-# INLINE put #-}
-
--- | @'modify' f@ is an action that updates the state to the result of
--- applying @f@ to the current state.
---
--- * @'modify' f = 'get' >>= ('put' . f)@
-modify :: (Monoid w, Monad m) => (s -> s) -> RWST r w s m ()
-modify f = RWST $ \ _ s -> return ((), f s, mempty)
-{-# INLINE modify #-}
-
--- | Get a specific component of the state, using a projection function
--- supplied.
---
--- * @'gets' f = 'liftM' f 'get'@
-gets :: (Monoid w, Monad m) => (s -> a) -> RWST r w s m a
-gets f = RWST $ \ _ s -> return (f s, s, mempty)
-{-# INLINE gets #-}
-
--- | Uniform lifting of a @callCC@ operation to the new monad.
--- This version rolls back to the original state on entering the
--- continuation.
-liftCallCC :: (Monoid w) =>
-    CallCC m (a,s,w) (b,s,w) -> CallCC (RWST r w s m) a b
-liftCallCC callCC f = RWST $ \ r s ->
-    callCC $ \ c ->
-    runRWST (f (\ a -> RWST $ \ _ _ -> c (a, s, mempty))) r s
-{-# INLINE liftCallCC #-}
-
--- | In-situ lifting of a @callCC@ operation to the new monad.
--- This version uses the current state on entering the continuation.
-liftCallCC' :: (Monoid w) =>
-    CallCC m (a,s,w) (b,s,w) -> CallCC (RWST r w s m) a b
-liftCallCC' callCC f = RWST $ \ r s ->
-    callCC $ \ c ->
-    runRWST (f (\ a -> RWST $ \ _ s' -> c (a, s', mempty))) r s
-{-# INLINE liftCallCC' #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a,s,w) -> Catch e (RWST r w s m) a
-liftCatch catchE m h =
-    RWST $ \ r s -> runRWST m r s `catchE` \ e -> runRWST (h e) r s
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/Strict.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/Strict.hs
deleted file mode 100644
index 557dd2028dd0..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/RWS/Strict.hs
+++ /dev/null
@@ -1,392 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.RWS.Strict
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- A monad transformer that combines 'ReaderT', 'WriterT' and 'StateT'.
--- This version is strict; for a lazy version with the same interface,
--- see "Control.Monad.Trans.RWS.Lazy".
--- Although the output is built strictly, it is not possible to
--- achieve constant space behaviour with this transformer: for that,
--- use "Control.Monad.Trans.RWS.CPS" instead.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.RWS.Strict (
-    -- * The RWS monad
-    RWS,
-    rws,
-    runRWS,
-    evalRWS,
-    execRWS,
-    mapRWS,
-    withRWS,
-    -- * The RWST monad transformer
-    RWST(..),
-    evalRWST,
-    execRWST,
-    mapRWST,
-    withRWST,
-    -- * Reader operations
-    reader,
-    ask,
-    local,
-    asks,
-    -- * Writer operations
-    writer,
-    tell,
-    listen,
-    listens,
-    pass,
-    censor,
-    -- * State operations
-    state,
-    get,
-    put,
-    modify,
-    gets,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCallCC',
-    liftCatch,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-import Data.Monoid
-
--- | A monad containing an environment of type @r@, output of type @w@
--- and an updatable state of type @s@.
-type RWS r w s = RWST r w s Identity
-
--- | Construct an RWS computation from a function.
--- (The inverse of 'runRWS'.)
-rws :: (r -> s -> (a, s, w)) -> RWS r w s a
-rws f = RWST (\ r s -> Identity (f r s))
-{-# INLINE rws #-}
-
--- | Unwrap an RWS computation as a function.
--- (The inverse of 'rws'.)
-runRWS :: RWS r w s a -> r -> s -> (a, s, w)
-runRWS m r s = runIdentity (runRWST m r s)
-{-# INLINE runRWS #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final value and output, discarding the final state.
-evalRWS :: RWS r w s a  -- ^RWS computation to execute
-        -> r            -- ^initial environment
-        -> s            -- ^initial value
-        -> (a, w)       -- ^final value and output
-evalRWS m r s = let
-    (a, _, w) = runRWS m r s
-    in (a, w)
-{-# INLINE evalRWS #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final state and output, discarding the final value.
-execRWS :: RWS r w s a  -- ^RWS computation to execute
-        -> r            -- ^initial environment
-        -> s            -- ^initial value
-        -> (s, w)       -- ^final state and output
-execRWS m r s = let
-    (_, s', w) = runRWS m r s
-    in (s', w)
-{-# INLINE execRWS #-}
-
--- | Map the return value, final state and output of a computation using
--- the given function.
---
--- * @'runRWS' ('mapRWS' f m) r s = f ('runRWS' m r s)@
-mapRWS :: ((a, s, w) -> (b, s, w')) -> RWS r w s a -> RWS r w' s b
-mapRWS f = mapRWST (Identity . f . runIdentity)
-{-# INLINE mapRWS #-}
-
--- | @'withRWS' f m@ executes action @m@ with an initial environment
--- and state modified by applying @f@.
---
--- * @'runRWS' ('withRWS' f m) r s = 'uncurry' ('runRWS' m) (f r s)@
-withRWS :: (r' -> s -> (r, s)) -> RWS r w s a -> RWS r' w s a
-withRWS = withRWST
-{-# INLINE withRWS #-}
-
--- ---------------------------------------------------------------------------
--- | A monad transformer adding reading an environment of type @r@,
--- collecting an output of type @w@ and updating a state of type @s@
--- to an inner monad @m@.
-newtype RWST r w s m a = RWST { runRWST :: r -> s -> m (a, s, w) }
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final value and output, discarding the final state.
-evalRWST :: (Monad m)
-         => RWST r w s m a      -- ^computation to execute
-         -> r                   -- ^initial environment
-         -> s                   -- ^initial value
-         -> m (a, w)            -- ^computation yielding final value and output
-evalRWST m r s = do
-    (a, _, w) <- runRWST m r s
-    return (a, w)
-{-# INLINE evalRWST #-}
-
--- | Evaluate a computation with the given initial state and environment,
--- returning the final state and output, discarding the final value.
-execRWST :: (Monad m)
-         => RWST r w s m a      -- ^computation to execute
-         -> r                   -- ^initial environment
-         -> s                   -- ^initial value
-         -> m (s, w)            -- ^computation yielding final state and output
-execRWST m r s = do
-    (_, s', w) <- runRWST m r s
-    return (s', w)
-{-# INLINE execRWST #-}
-
--- | Map the inner computation using the given function.
---
--- * @'runRWST' ('mapRWST' f m) r s = f ('runRWST' m r s)@
-mapRWST :: (m (a, s, w) -> n (b, s, w')) -> RWST r w s m a -> RWST r w' s n b
-mapRWST f m = RWST $ \ r s -> f (runRWST m r s)
-{-# INLINE mapRWST #-}
-
--- | @'withRWST' f m@ executes action @m@ with an initial environment
--- and state modified by applying @f@.
---
--- * @'runRWST' ('withRWST' f m) r s = 'uncurry' ('runRWST' m) (f r s)@
-withRWST :: (r' -> s -> (r, s)) -> RWST r w s m a -> RWST r' w s m a
-withRWST f m = RWST $ \ r s -> uncurry (runRWST m) (f r s)
-{-# INLINE withRWST #-}
-
-instance (Functor m) => Functor (RWST r w s m) where
-    fmap f m = RWST $ \ r s ->
-        fmap (\ (a, s', w) -> (f a, s', w)) $ runRWST m r s
-    {-# INLINE fmap #-}
-
-instance (Monoid w, Functor m, Monad m) => Applicative (RWST r w s m) where
-    pure a = RWST $ \ _ s -> return (a, s, mempty)
-    {-# INLINE pure #-}
-    RWST mf <*> RWST mx = RWST $ \ r s -> do
-        (f, s', w)  <- mf r s
-        (x, s'',w') <- mx r s'
-        return (f x, s'', w `mappend` w')
-    {-# INLINE (<*>) #-}
-
-instance (Monoid w, Functor m, MonadPlus m) => Alternative (RWST r w s m) where
-    empty = RWST $ \ _ _ -> mzero
-    {-# INLINE empty #-}
-    RWST m <|> RWST n = RWST $ \ r s -> m r s `mplus` n r s
-    {-# INLINE (<|>) #-}
-
-instance (Monoid w, Monad m) => Monad (RWST r w s m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = RWST $ \ _ s -> return (a, s, mempty)
-    {-# INLINE return #-}
-#endif
-    m >>= k  = RWST $ \ r s -> do
-        (a, s', w)  <- runRWST m r s
-        (b, s'',w') <- runRWST (k a) r s'
-        return (b, s'', w `mappend` w')
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = RWST $ \ _ _ -> fail msg
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Monoid w, Fail.MonadFail m) => Fail.MonadFail (RWST r w s m) where
-    fail msg = RWST $ \ _ _ -> Fail.fail msg
-    {-# INLINE fail #-}
-#endif
-
-instance (Monoid w, MonadPlus m) => MonadPlus (RWST r w s m) where
-    mzero = RWST $ \ _ _ -> mzero
-    {-# INLINE mzero #-}
-    RWST m `mplus` RWST n = RWST $ \ r s -> m r s `mplus` n r s
-    {-# INLINE mplus #-}
-
-instance (Monoid w, MonadFix m) => MonadFix (RWST r w s m) where
-    mfix f = RWST $ \ r s -> mfix $ \ ~(a, _, _) -> runRWST (f a) r s
-    {-# INLINE mfix #-}
-
-instance (Monoid w) => MonadTrans (RWST r w s) where
-    lift m = RWST $ \ _ s -> do
-        a <- m
-        return (a, s, mempty)
-    {-# INLINE lift #-}
-
-instance (Monoid w, MonadIO m) => MonadIO (RWST r w s m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (RWST r w s m) where
-    contramap f m = RWST $ \r s ->
-      contramap (\ (a, s', w) -> (f a, s', w)) $ runRWST m r s
-    {-# INLINE contramap #-}
-#endif
-
--- ---------------------------------------------------------------------------
--- Reader operations
-
--- | Constructor for computations in the reader monad (equivalent to 'asks').
-reader :: (Monoid w, Monad m) => (r -> a) -> RWST r w s m a
-reader = asks
-{-# INLINE reader #-}
-
--- | Fetch the value of the environment.
-ask :: (Monoid w, Monad m) => RWST r w s m r
-ask = RWST $ \ r s -> return (r, s, mempty)
-{-# INLINE ask #-}
-
--- | Execute a computation in a modified environment
---
--- * @'runRWST' ('local' f m) r s = 'runRWST' m (f r) s@
-local :: (r -> r) -> RWST r w s m a -> RWST r w s m a
-local f m = RWST $ \ r s -> runRWST m (f r) s
-{-# INLINE local #-}
-
--- | Retrieve a function of the current environment.
---
--- * @'asks' f = 'liftM' f 'ask'@
-asks :: (Monoid w, Monad m) => (r -> a) -> RWST r w s m a
-asks f = RWST $ \ r s -> return (f r, s, mempty)
-{-# INLINE asks #-}
-
--- ---------------------------------------------------------------------------
--- Writer operations
-
--- | Construct a writer computation from a (result, output) pair.
-writer :: (Monad m) => (a, w) -> RWST r w s m a
-writer (a, w) = RWST $ \ _ s -> return (a, s, w)
-{-# INLINE writer #-}
-
--- | @'tell' w@ is an action that produces the output @w@.
-tell :: (Monad m) => w -> RWST r w s m ()
-tell w = RWST $ \ _ s -> return ((),s,w)
-{-# INLINE tell #-}
-
--- | @'listen' m@ is an action that executes the action @m@ and adds its
--- output to the value of the computation.
---
--- * @'runRWST' ('listen' m) r s = 'liftM' (\\ (a, w) -> ((a, w), w)) ('runRWST' m r s)@
-listen :: (Monad m) => RWST r w s m a -> RWST r w s m (a, w)
-listen m = RWST $ \ r s -> do
-    (a, s', w) <- runRWST m r s
-    return ((a, w), s', w)
-{-# INLINE listen #-}
-
--- | @'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.
---
--- * @'listens' f m = 'liftM' (id *** f) ('listen' m)@
---
--- * @'runRWST' ('listens' f m) r s = 'liftM' (\\ (a, w) -> ((a, f w), w)) ('runRWST' m r s)@
-listens :: (Monad m) => (w -> b) -> RWST r w s m a -> RWST r w s m (a, b)
-listens f m = RWST $ \ r s -> do
-    (a, s', w) <- runRWST m r s
-    return ((a, f w), s', w)
-{-# INLINE listens #-}
-
--- | @'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.
---
--- * @'runRWST' ('pass' m) r s = 'liftM' (\\ ((a, f), w) -> (a, f w)) ('runRWST' m r s)@
-pass :: (Monad m) => RWST r w s m (a, w -> w) -> RWST r w s m a
-pass m = RWST $ \ r s -> do
-    ((a, f), s', w) <- runRWST m r s
-    return (a, s', f w)
-{-# INLINE pass #-}
-
--- | @'censor' f m@ is an action that executes the action @m@ and
--- applies the function @f@ to its output, leaving the return value
--- unchanged.
---
--- * @'censor' f m = 'pass' ('liftM' (\\ x -> (x,f)) m)@
---
--- * @'runRWST' ('censor' f m) r s = 'liftM' (\\ (a, w) -> (a, f w)) ('runRWST' m r s)@
-censor :: (Monad m) => (w -> w) -> RWST r w s m a -> RWST r w s m a
-censor f m = RWST $ \ r s -> do
-    (a, s', w) <- runRWST m r s
-    return (a, s', f w)
-{-# INLINE censor #-}
-
--- ---------------------------------------------------------------------------
--- State operations
-
--- | Construct a state monad computation from a state transformer function.
-state :: (Monoid w, Monad m) => (s -> (a,s)) -> RWST r w s m a
-state f = RWST $ \ _ s -> case f s of (a,s') -> return (a, s', mempty)
-{-# INLINE state #-}
-
--- | Fetch the current value of the state within the monad.
-get :: (Monoid w, Monad m) => RWST r w s m s
-get = RWST $ \ _ s -> return (s, s, mempty)
-{-# INLINE get #-}
-
--- | @'put' s@ sets the state within the monad to @s@.
-put :: (Monoid w, Monad m) => s -> RWST r w s m ()
-put s = RWST $ \ _ _ -> return ((), s, mempty)
-{-# INLINE put #-}
-
--- | @'modify' f@ is an action that updates the state to the result of
--- applying @f@ to the current state.
---
--- * @'modify' f = 'get' >>= ('put' . f)@
-modify :: (Monoid w, Monad m) => (s -> s) -> RWST r w s m ()
-modify f = RWST $ \ _ s -> return ((), f s, mempty)
-{-# INLINE modify #-}
-
--- | Get a specific component of the state, using a projection function
--- supplied.
---
--- * @'gets' f = 'liftM' f 'get'@
-gets :: (Monoid w, Monad m) => (s -> a) -> RWST r w s m a
-gets f = RWST $ \ _ s -> return (f s, s, mempty)
-{-# INLINE gets #-}
-
--- | Uniform lifting of a @callCC@ operation to the new monad.
--- This version rolls back to the original state on entering the
--- continuation.
-liftCallCC :: (Monoid w) =>
-    CallCC m (a,s,w) (b,s,w) -> CallCC (RWST r w s m) a b
-liftCallCC callCC f = RWST $ \ r s ->
-    callCC $ \ c ->
-    runRWST (f (\ a -> RWST $ \ _ _ -> c (a, s, mempty))) r s
-{-# INLINE liftCallCC #-}
-
--- | In-situ lifting of a @callCC@ operation to the new monad.
--- This version uses the current state on entering the continuation.
-liftCallCC' :: (Monoid w) =>
-    CallCC m (a,s,w) (b,s,w) -> CallCC (RWST r w s m) a b
-liftCallCC' callCC f = RWST $ \ r s ->
-    callCC $ \ c ->
-    runRWST (f (\ a -> RWST $ \ _ s' -> c (a, s', mempty))) r s
-{-# INLINE liftCallCC' #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a,s,w) -> Catch e (RWST r w s m) a
-liftCatch catchE m h =
-    RWST $ \ r s -> runRWST m r s `catchE` \ e -> runRWST (h e) r s
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Reader.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Reader.hs
deleted file mode 100644
index 25e3ad27c3c6..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Reader.hs
+++ /dev/null
@@ -1,262 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Reader
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Declaration of the 'ReaderT' monad transformer, which adds a static
--- environment to a given monad.
---
--- If the computation is to modify the stored information, use
--- "Control.Monad.Trans.State" instead.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Reader (
-    -- * The Reader monad
-    Reader,
-    reader,
-    runReader,
-    mapReader,
-    withReader,
-    -- * The ReaderT monad transformer
-    ReaderT(..),
-    mapReaderT,
-    withReaderT,
-    -- * Reader operations
-    ask,
-    local,
-    asks,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCatch,
-    ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-#if !(MIN_VERSION_base(4,6,0))
-import Control.Monad.Instances ()  -- deprecated from base-4.6
-#endif
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith))
-#endif
-#if MIN_VERSION_base(4,2,0)
-import Data.Functor(Functor(..))
-#endif
-
--- | The parameterizable reader monad.
---
--- Computations are functions of a shared environment.
---
--- The 'return' function ignores the environment, while @>>=@ passes
--- the inherited environment to both subcomputations.
-type Reader r = ReaderT r Identity
-
--- | Constructor for computations in the reader monad (equivalent to 'asks').
-reader :: (Monad m) => (r -> a) -> ReaderT r m a
-reader f = ReaderT (return . f)
-{-# INLINE reader #-}
-
--- | Runs a @Reader@ and extracts the final value from it.
--- (The inverse of 'reader'.)
-runReader
-    :: Reader r a       -- ^ A @Reader@ to run.
-    -> r                -- ^ An initial environment.
-    -> a
-runReader m = runIdentity . runReaderT m
-{-# INLINE runReader #-}
-
--- | Transform the value returned by a @Reader@.
---
--- * @'runReader' ('mapReader' f m) = f . 'runReader' m@
-mapReader :: (a -> b) -> Reader r a -> Reader r b
-mapReader f = mapReaderT (Identity . f . runIdentity)
-{-# INLINE mapReader #-}
-
--- | Execute a computation in a modified environment
--- (a specialization of 'withReaderT').
---
--- * @'runReader' ('withReader' f m) = 'runReader' m . f@
-withReader
-    :: (r' -> r)        -- ^ The function to modify the environment.
-    -> Reader r a       -- ^ Computation to run in the modified environment.
-    -> Reader r' a
-withReader = withReaderT
-{-# INLINE withReader #-}
-
--- | The reader monad transformer,
--- which adds a read-only environment to the given monad.
---
--- The 'return' function ignores the environment, while @>>=@ passes
--- the inherited environment to both subcomputations.
-newtype ReaderT r m a = ReaderT { runReaderT :: r -> m a }
-
--- | Transform the computation inside a @ReaderT@.
---
--- * @'runReaderT' ('mapReaderT' f m) = f . 'runReaderT' m@
-mapReaderT :: (m a -> n b) -> ReaderT r m a -> ReaderT r n b
-mapReaderT f m = ReaderT $ f . runReaderT m
-{-# INLINE mapReaderT #-}
-
--- | Execute a computation in a modified environment
--- (a more general version of 'local').
---
--- * @'runReaderT' ('withReaderT' f m) = 'runReaderT' m . f@
-withReaderT
-    :: (r' -> r)        -- ^ The function to modify the environment.
-    -> ReaderT r m a    -- ^ Computation to run in the modified environment.
-    -> ReaderT r' m a
-withReaderT f m = ReaderT $ runReaderT m . f
-{-# INLINE withReaderT #-}
-
-instance (Functor m) => Functor (ReaderT r m) where
-    fmap f  = mapReaderT (fmap f)
-    {-# INLINE fmap #-}
-#if MIN_VERSION_base(4,2,0)
-    x <$ v = mapReaderT (x <$) v
-    {-# INLINE (<$) #-}
-#endif
-
-instance (Applicative m) => Applicative (ReaderT r m) where
-    pure    = liftReaderT . pure
-    {-# INLINE pure #-}
-    f <*> v = ReaderT $ \ r -> runReaderT f r <*> runReaderT v r
-    {-# INLINE (<*>) #-}
-#if MIN_VERSION_base(4,2,0)
-    u *> v = ReaderT $ \ r -> runReaderT u r *> runReaderT v r
-    {-# INLINE (*>) #-}
-    u <* v = ReaderT $ \ r -> runReaderT u r <* runReaderT v r
-    {-# INLINE (<*) #-}
-#endif
-#if MIN_VERSION_base(4,10,0)
-    liftA2 f x y = ReaderT $ \ r -> liftA2 f (runReaderT x r) (runReaderT y r)
-    {-# INLINE liftA2 #-}
-#endif
-
-instance (Alternative m) => Alternative (ReaderT r m) where
-    empty   = liftReaderT empty
-    {-# INLINE empty #-}
-    m <|> n = ReaderT $ \ r -> runReaderT m r <|> runReaderT n r
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (ReaderT r m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return   = lift . return
-    {-# INLINE return #-}
-#endif
-    m >>= k  = ReaderT $ \ r -> do
-        a <- runReaderT m r
-        runReaderT (k a) r
-    {-# INLINE (>>=) #-}
-#if MIN_VERSION_base(4,8,0)
-    (>>) = (*>)
-#else
-    m >> k = ReaderT $ \ r -> runReaderT m r >> runReaderT k r
-#endif
-    {-# INLINE (>>) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = lift (fail msg)
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (ReaderT r m) where
-    fail msg = lift (Fail.fail msg)
-    {-# INLINE fail #-}
-#endif
-
-instance (MonadPlus m) => MonadPlus (ReaderT r m) where
-    mzero       = lift mzero
-    {-# INLINE mzero #-}
-    m `mplus` n = ReaderT $ \ r -> runReaderT m r `mplus` runReaderT n r
-    {-# INLINE mplus #-}
-
-instance (MonadFix m) => MonadFix (ReaderT r m) where
-    mfix f = ReaderT $ \ r -> mfix $ \ a -> runReaderT (f a) r
-    {-# INLINE mfix #-}
-
-instance MonadTrans (ReaderT r) where
-    lift   = liftReaderT
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (ReaderT r m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,4,0)
-instance (MonadZip m) => MonadZip (ReaderT r m) where
-    mzipWith f (ReaderT m) (ReaderT n) = ReaderT $ \ a ->
-        mzipWith f (m a) (n a)
-    {-# INLINE mzipWith #-}
-#endif
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (ReaderT r m) where
-    contramap f = ReaderT . fmap (contramap f) . runReaderT
-    {-# INLINE contramap #-}
-#endif
-
-liftReaderT :: m a -> ReaderT r m a
-liftReaderT m = ReaderT (const m)
-{-# INLINE liftReaderT #-}
-
--- | Fetch the value of the environment.
-ask :: (Monad m) => ReaderT r m r
-ask = ReaderT return
-{-# INLINE ask #-}
-
--- | Execute a computation in a modified environment
--- (a specialization of 'withReaderT').
---
--- * @'runReaderT' ('local' f m) = 'runReaderT' m . f@
-local
-    :: (r -> r)         -- ^ The function to modify the environment.
-    -> ReaderT r m a    -- ^ Computation to run in the modified environment.
-    -> ReaderT r m a
-local = withReaderT
-{-# INLINE local #-}
-
--- | Retrieve a function of the current environment.
---
--- * @'asks' f = 'liftM' f 'ask'@
-asks :: (Monad m)
-    => (r -> a)         -- ^ The selector function to apply to the environment.
-    -> ReaderT r m a
-asks f = ReaderT (return . f)
-{-# INLINE asks #-}
-
--- | Lift a @callCC@ operation to the new monad.
-liftCallCC :: CallCC m a b -> CallCC (ReaderT r m) a b
-liftCallCC callCC f = ReaderT $ \ r ->
-    callCC $ \ c ->
-    runReaderT (f (ReaderT . const . c)) r
-{-# INLINE liftCallCC #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m a -> Catch e (ReaderT r m) a
-liftCatch f m h =
-    ReaderT $ \ r -> f (runReaderT m r) (\ e -> runReaderT (h e) r)
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Select.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Select.hs
deleted file mode 100644
index 22fdf8fd8abc..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Select.hs
+++ /dev/null
@@ -1,161 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Select
--- Copyright   :  (c) Ross Paterson 2017
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Selection monad transformer, modelling search algorithms.
---
--- * Martin Escardo and Paulo Oliva.
---   "Selection functions, bar recursion and backward induction",
---   /Mathematical Structures in Computer Science/ 20:2 (2010), pp. 127-168.
---   <https://www.cs.bham.ac.uk/~mhe/papers/selection-escardo-oliva.pdf>
---
--- * Jules Hedges. "Monad transformers for backtracking search".
---   In /Proceedings of MSFP 2014/. <https://arxiv.org/abs/1406.2058>
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Select (
-    -- * The Select monad
-    Select,
-    select,
-    runSelect,
-    mapSelect,
-    -- * The SelectT monad transformer
-    SelectT(SelectT),
-    runSelectT,
-    mapSelectT,
-    -- * Monad transformation
-    selectToContT,
-    selectToCont,
-    ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Trans.Class
-import Control.Monad.Trans.Cont
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Data.Functor.Identity
-
--- | Selection monad.
-type Select r = SelectT r Identity
-
--- | Constructor for computations in the selection monad.
-select :: ((a -> r) -> a) -> Select r a
-select f = SelectT $ \ k -> Identity (f (runIdentity . k))
-{-# INLINE select #-}
-
--- | Runs a @Select@ computation with a function for evaluating answers
--- to select a particular answer.  (The inverse of 'select'.)
-runSelect :: Select r a -> (a -> r) -> a
-runSelect m k = runIdentity (runSelectT m (Identity . k))
-{-# INLINE runSelect #-}
-
--- | Apply a function to transform the result of a selection computation.
---
--- * @'runSelect' ('mapSelect' f m) = f . 'runSelect' m@
-mapSelect :: (a -> a) -> Select r a -> Select r a
-mapSelect f = mapSelectT (Identity . f . runIdentity)
-{-# INLINE mapSelect #-}
-
--- | Selection monad transformer.
---
--- 'SelectT' is not a functor on the category of monads, and many operations
--- cannot be lifted through it.
-newtype SelectT r m a = SelectT ((a -> m r) -> m a)
-
--- | Runs a @SelectT@ computation with a function for evaluating answers
--- to select a particular answer.  (The inverse of 'select'.)
-runSelectT :: SelectT r m a -> (a -> m r) -> m a
-runSelectT (SelectT g) = g
-{-# INLINE runSelectT #-}
-
--- | Apply a function to transform the result of a selection computation.
--- This has a more restricted type than the @map@ operations for other
--- monad transformers, because 'SelectT' does not define a functor in
--- the category of monads.
---
--- * @'runSelectT' ('mapSelectT' f m) = f . 'runSelectT' m@
-mapSelectT :: (m a -> m a) -> SelectT r m a -> SelectT r m a
-mapSelectT f m = SelectT $ f . runSelectT m
-{-# INLINE mapSelectT #-}
-
-instance (Functor m) => Functor (SelectT r m) where
-    fmap f (SelectT g) = SelectT (fmap f . g . (. f))
-    {-# INLINE fmap #-}
-
-instance (Functor m, Monad m) => Applicative (SelectT r m) where
-    pure = lift . return
-    {-# INLINE pure #-}
-    SelectT gf <*> SelectT gx = SelectT $ \ k -> do
-        let h f = liftM f (gx (k . f))
-        f <- gf ((>>= k) . h)
-        h f
-    {-# INLINE (<*>) #-}
-    m *> k = m >>= \_ -> k
-    {-# INLINE (*>) #-}
-
-instance (Functor m, MonadPlus m) => Alternative (SelectT r m) where
-    empty = mzero
-    {-# INLINE empty #-}
-    (<|>) = mplus
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (SelectT r m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return = lift . return
-    {-# INLINE return #-}
-#endif
-    SelectT g >>= f = SelectT $ \ k -> do
-        let h x = runSelectT (f x) k
-        y <- g ((>>= k) . h)
-        h y
-    {-# INLINE (>>=) #-}
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (SelectT r m) where
-    fail msg = lift (Fail.fail msg)
-    {-# INLINE fail #-}
-#endif
-
-instance (MonadPlus m) => MonadPlus (SelectT r m) where
-    mzero = SelectT (const mzero)
-    {-# INLINE mzero #-}
-    SelectT f `mplus` SelectT g = SelectT $ \ k -> f k `mplus` g k
-    {-# INLINE mplus #-}
-
-instance MonadTrans (SelectT r) where
-    lift = SelectT . const
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (SelectT r m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
--- | Convert a selection computation to a continuation-passing computation.
-selectToContT :: (Monad m) => SelectT r m a -> ContT r m a
-selectToContT (SelectT g) = ContT $ \ k -> g k >>= k
-{-# INLINE selectToCont #-}
-
--- | Deprecated name for 'selectToContT'.
-{-# DEPRECATED selectToCont "Use selectToContT instead" #-}
-selectToCont :: (Monad m) => SelectT r m a -> ContT r m a
-selectToCont = selectToContT
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State.hs
deleted file mode 100644
index 36de964ea1d3..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State.hs
+++ /dev/null
@@ -1,33 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.State
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- State monads, passing an updatable state through a computation.
---
--- Some computations may not require the full power of state transformers:
---
--- * For a read-only state, see "Control.Monad.Trans.Reader".
---
--- * To accumulate a value without using it on the way, see
---   "Control.Monad.Trans.Writer".
---
--- This version is lazy; for a strict version, see
--- "Control.Monad.Trans.State.Strict", which has the same interface.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.State (
-  module Control.Monad.Trans.State.Lazy
-  ) where
-
-import Control.Monad.Trans.State.Lazy
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State/Lazy.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State/Lazy.hs
deleted file mode 100644
index d7cdde5444a8..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State/Lazy.hs
+++ /dev/null
@@ -1,428 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.State.Lazy
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Lazy state monads, passing an updatable state through a computation.
--- See below for examples.
---
--- Some computations may not require the full power of state transformers:
---
--- * For a read-only state, see "Control.Monad.Trans.Reader".
---
--- * To accumulate a value without using it on the way, see
---   "Control.Monad.Trans.Writer".
---
--- In this version, sequencing of computations is lazy, so that for
--- example the following produces a usable result:
---
--- > evalState (sequence $ repeat $ do { n <- get; put (n*2); return n }) 1
---
--- For a strict version with the same interface, see
--- "Control.Monad.Trans.State.Strict".
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.State.Lazy (
-    -- * The State monad
-    State,
-    state,
-    runState,
-    evalState,
-    execState,
-    mapState,
-    withState,
-    -- * The StateT monad transformer
-    StateT(..),
-    evalStateT,
-    execStateT,
-    mapStateT,
-    withStateT,
-    -- * State operations
-    get,
-    put,
-    modify,
-    modify',
-    gets,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCallCC',
-    liftCatch,
-    liftListen,
-    liftPass,
-    -- * Examples
-    -- ** State monads
-    -- $examples
-
-    -- ** Counting
-    -- $counting
-
-    -- ** Labelling trees
-    -- $labelling
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-
--- ---------------------------------------------------------------------------
--- | A state monad parameterized by the type @s@ of the state to carry.
---
--- The 'return' function leaves the state unchanged, while @>>=@ uses
--- the final state of the first computation as the initial state of
--- the second.
-type State s = StateT s Identity
-
--- | Construct a state monad computation from a function.
--- (The inverse of 'runState'.)
-state :: (Monad m)
-      => (s -> (a, s))  -- ^pure state transformer
-      -> StateT s m a   -- ^equivalent state-passing computation
-state f = StateT (return . f)
-{-# INLINE state #-}
-
--- | Unwrap a state monad computation as a function.
--- (The inverse of 'state'.)
-runState :: State s a   -- ^state-passing computation to execute
-         -> s           -- ^initial state
-         -> (a, s)      -- ^return value and final state
-runState m = runIdentity . runStateT m
-{-# INLINE runState #-}
-
--- | Evaluate a state computation with the given initial state
--- and return the final value, discarding the final state.
---
--- * @'evalState' m s = 'fst' ('runState' m s)@
-evalState :: State s a  -- ^state-passing computation to execute
-          -> s          -- ^initial value
-          -> a          -- ^return value of the state computation
-evalState m s = fst (runState m s)
-{-# INLINE evalState #-}
-
--- | Evaluate a state computation with the given initial state
--- and return the final state, discarding the final value.
---
--- * @'execState' m s = 'snd' ('runState' m s)@
-execState :: State s a  -- ^state-passing computation to execute
-          -> s          -- ^initial value
-          -> s          -- ^final state
-execState m s = snd (runState m s)
-{-# INLINE execState #-}
-
--- | Map both the return value and final state of a computation using
--- the given function.
---
--- * @'runState' ('mapState' f m) = f . 'runState' m@
-mapState :: ((a, s) -> (b, s)) -> State s a -> State s b
-mapState f = mapStateT (Identity . f . runIdentity)
-{-# INLINE mapState #-}
-
--- | @'withState' f m@ executes action @m@ on a state modified by
--- applying @f@.
---
--- * @'withState' f m = 'modify' f >> m@
-withState :: (s -> s) -> State s a -> State s a
-withState = withStateT
-{-# INLINE withState #-}
-
--- ---------------------------------------------------------------------------
--- | A state transformer monad parameterized by:
---
---   * @s@ - The state.
---
---   * @m@ - The inner monad.
---
--- The 'return' function leaves the state unchanged, while @>>=@ uses
--- the final state of the first computation as the initial state of
--- the second.
-newtype StateT s m a = StateT { runStateT :: s -> m (a,s) }
-
--- | Evaluate a state computation with the given initial state
--- and return the final value, discarding the final state.
---
--- * @'evalStateT' m s = 'liftM' 'fst' ('runStateT' m s)@
-evalStateT :: (Monad m) => StateT s m a -> s -> m a
-evalStateT m s = do
-    ~(a, _) <- runStateT m s
-    return a
-{-# INLINE evalStateT #-}
-
--- | Evaluate a state computation with the given initial state
--- and return the final state, discarding the final value.
---
--- * @'execStateT' m s = 'liftM' 'snd' ('runStateT' m s)@
-execStateT :: (Monad m) => StateT s m a -> s -> m s
-execStateT m s = do
-    ~(_, s') <- runStateT m s
-    return s'
-{-# INLINE execStateT #-}
-
--- | Map both the return value and final state of a computation using
--- the given function.
---
--- * @'runStateT' ('mapStateT' f m) = f . 'runStateT' m@
-mapStateT :: (m (a, s) -> n (b, s)) -> StateT s m a -> StateT s n b
-mapStateT f m = StateT $ f . runStateT m
-{-# INLINE mapStateT #-}
-
--- | @'withStateT' f m@ executes action @m@ on a state modified by
--- applying @f@.
---
--- * @'withStateT' f m = 'modify' f >> m@
-withStateT :: (s -> s) -> StateT s m a -> StateT s m a
-withStateT f m = StateT $ runStateT m . f
-{-# INLINE withStateT #-}
-
-instance (Functor m) => Functor (StateT s m) where
-    fmap f m = StateT $ \ s ->
-        fmap (\ ~(a, s') -> (f a, s')) $ runStateT m s
-    {-# INLINE fmap #-}
-
-instance (Functor m, Monad m) => Applicative (StateT s m) where
-    pure a = StateT $ \ s -> return (a, s)
-    {-# INLINE pure #-}
-    StateT mf <*> StateT mx = StateT $ \ s -> do
-        ~(f, s') <- mf s
-        ~(x, s'') <- mx s'
-        return (f x, s'')
-    {-# INLINE (<*>) #-}
-    m *> k = m >>= \_ -> k
-    {-# INLINE (*>) #-}
-
-instance (Functor m, MonadPlus m) => Alternative (StateT s m) where
-    empty = StateT $ \ _ -> mzero
-    {-# INLINE empty #-}
-    StateT m <|> StateT n = StateT $ \ s -> m s `mplus` n s
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (StateT s m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = StateT $ \ s -> return (a, s)
-    {-# INLINE return #-}
-#endif
-    m >>= k  = StateT $ \ s -> do
-        ~(a, s') <- runStateT m s
-        runStateT (k a) s'
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail str = StateT $ \ _ -> fail str
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (StateT s m) where
-    fail str = StateT $ \ _ -> Fail.fail str
-    {-# INLINE fail #-}
-#endif
-
-instance (MonadPlus m) => MonadPlus (StateT s m) where
-    mzero       = StateT $ \ _ -> mzero
-    {-# INLINE mzero #-}
-    StateT m `mplus` StateT n = StateT $ \ s -> m s `mplus` n s
-    {-# INLINE mplus #-}
-
-instance (MonadFix m) => MonadFix (StateT s m) where
-    mfix f = StateT $ \ s -> mfix $ \ ~(a, _) -> runStateT (f a) s
-    {-# INLINE mfix #-}
-
-instance MonadTrans (StateT s) where
-    lift m = StateT $ \ s -> do
-        a <- m
-        return (a, s)
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (StateT s m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (StateT s m) where
-    contramap f m = StateT $ \s ->
-      contramap (\ ~(a, s') -> (f a, s')) $ runStateT m s
-    {-# INLINE contramap #-}
-#endif
-
--- | Fetch the current value of the state within the monad.
-get :: (Monad m) => StateT s m s
-get = state $ \ s -> (s, s)
-{-# INLINE get #-}
-
--- | @'put' s@ sets the state within the monad to @s@.
-put :: (Monad m) => s -> StateT s m ()
-put s = state $ \ _ -> ((), s)
-{-# INLINE put #-}
-
--- | @'modify' f@ is an action that updates the state to the result of
--- applying @f@ to the current state.
---
--- * @'modify' f = 'get' >>= ('put' . f)@
-modify :: (Monad m) => (s -> s) -> StateT s m ()
-modify f = state $ \ s -> ((), f s)
-{-# INLINE modify #-}
-
--- | A variant of 'modify' in which the computation is strict in the
--- new state.
---
--- * @'modify'' f = 'get' >>= (('$!') 'put' . f)@
-modify' :: (Monad m) => (s -> s) -> StateT s m ()
-modify' f = do
-    s <- get
-    put $! f s
-{-# INLINE modify' #-}
-
--- | Get a specific component of the state, using a projection function
--- supplied.
---
--- * @'gets' f = 'liftM' f 'get'@
-gets :: (Monad m) => (s -> a) -> StateT s m a
-gets f = state $ \ s -> (f s, s)
-{-# INLINE gets #-}
-
--- | Uniform lifting of a @callCC@ operation to the new monad.
--- This version rolls back to the original state on entering the
--- continuation.
-liftCallCC :: CallCC m (a,s) (b,s) -> CallCC (StateT s m) a b
-liftCallCC callCC f = StateT $ \ s ->
-    callCC $ \ c ->
-    runStateT (f (\ a -> StateT $ \ _ -> c (a, s))) s
-{-# INLINE liftCallCC #-}
-
--- | In-situ lifting of a @callCC@ operation to the new monad.
--- This version uses the current state on entering the continuation.
--- It does not satisfy the uniformity property (see "Control.Monad.Signatures").
-liftCallCC' :: CallCC m (a,s) (b,s) -> CallCC (StateT s m) a b
-liftCallCC' callCC f = StateT $ \ s ->
-    callCC $ \ c ->
-    runStateT (f (\ a -> StateT $ \ s' -> c (a, s'))) s
-{-# INLINE liftCallCC' #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a,s) -> Catch e (StateT s m) a
-liftCatch catchE m h =
-    StateT $ \ s -> runStateT m s `catchE` \ e -> runStateT (h e) s
-{-# INLINE liftCatch #-}
-
--- | Lift a @listen@ operation to the new monad.
-liftListen :: (Monad m) => Listen w m (a,s) -> Listen w (StateT s m) a
-liftListen listen m = StateT $ \ s -> do
-    ~((a, s'), w) <- listen (runStateT m s)
-    return ((a, w), s')
-{-# INLINE liftListen #-}
-
--- | Lift a @pass@ operation to the new monad.
-liftPass :: (Monad m) => Pass w m (a,s) -> Pass w (StateT s m) a
-liftPass pass m = StateT $ \ s -> pass $ do
-    ~((a, f), s') <- runStateT m s
-    return ((a, s'), f)
-{-# INLINE liftPass #-}
-
-{- $examples
-
-Parser from ParseLib with Hugs:
-
-> type Parser a = StateT String [] a
->    ==> StateT (String -> [(a,String)])
-
-For example, item can be written as:
-
-> item = do (x:xs) <- get
->        put xs
->        return x
->
-> type BoringState s a = StateT s Identity a
->      ==> StateT (s -> Identity (a,s))
->
-> type StateWithIO s a = StateT s IO a
->      ==> StateT (s -> IO (a,s))
->
-> type StateWithErr s a = StateT s Maybe a
->      ==> StateT (s -> Maybe (a,s))
-
--}
-
-{- $counting
-
-A function to increment a counter.
-Taken from the paper \"Generalising Monads to Arrows\",
-John Hughes (<http://www.cse.chalmers.se/~rjmh/>), November 1998:
-
-> tick :: State Int Int
-> tick = do n <- get
->           put (n+1)
->           return n
-
-Add one to the given number using the state monad:
-
-> plusOne :: Int -> Int
-> plusOne n = execState tick n
-
-A contrived addition example. Works only with positive numbers:
-
-> plus :: Int -> Int -> Int
-> plus n x = execState (sequence $ replicate n tick) x
-
--}
-
-{- $labelling
-
-An example from /The Craft of Functional Programming/, Simon
-Thompson (<http://www.cs.kent.ac.uk/people/staff/sjt/>),
-Addison-Wesley 1999: \"Given an arbitrary tree, transform it to a
-tree of integers in which the original elements are replaced by
-natural numbers, starting from 0.  The same element has to be
-replaced by the same number at every occurrence, and when we meet
-an as-yet-unvisited element we have to find a \'new\' number to match
-it with:\"
-
-> data Tree a = Nil | Node a (Tree a) (Tree a) deriving (Show, Eq)
-> type Table a = [a]
-
-> numberTree :: Eq a => Tree a -> State (Table a) (Tree Int)
-> numberTree Nil = return Nil
-> numberTree (Node x t1 t2) = do
->     num <- numberNode x
->     nt1 <- numberTree t1
->     nt2 <- numberTree t2
->     return (Node num nt1 nt2)
->   where
->     numberNode :: Eq a => a -> State (Table a) Int
->     numberNode x = do
->         table <- get
->         case elemIndex x table of
->             Nothing -> do
->                 put (table ++ [x])
->                 return (length table)
->             Just i -> return i
-
-numTree applies numberTree with an initial state:
-
-> numTree :: (Eq a) => Tree a -> Tree Int
-> numTree t = evalState (numberTree t) []
-
-> testTree = Node "Zero" (Node "One" (Node "Two" Nil Nil) (Node "One" (Node "Zero" Nil Nil) Nil)) Nil
-> numTree testTree => Node 0 (Node 1 (Node 2 Nil Nil) (Node 1 (Node 0 Nil Nil) Nil)) Nil
-
--}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State/Strict.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State/Strict.hs
deleted file mode 100644
index d0fb58edb4cf..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/State/Strict.hs
+++ /dev/null
@@ -1,425 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.State.Strict
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Strict state monads, passing an updatable state through a computation.
--- See below for examples.
---
--- Some computations may not require the full power of state transformers:
---
--- * For a read-only state, see "Control.Monad.Trans.Reader".
---
--- * To accumulate a value without using it on the way, see
---   "Control.Monad.Trans.Writer".
---
--- In this version, sequencing of computations is strict (but computations
--- are not strict in the state unless you force it with 'seq' or the like).
--- For a lazy version with the same interface, see
--- "Control.Monad.Trans.State.Lazy".
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.State.Strict (
-    -- * The State monad
-    State,
-    state,
-    runState,
-    evalState,
-    execState,
-    mapState,
-    withState,
-    -- * The StateT monad transformer
-    StateT(..),
-    evalStateT,
-    execStateT,
-    mapStateT,
-    withStateT,
-    -- * State operations
-    get,
-    put,
-    modify,
-    modify',
-    gets,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCallCC',
-    liftCatch,
-    liftListen,
-    liftPass,
-    -- * Examples
-    -- ** State monads
-    -- $examples
-
-    -- ** Counting
-    -- $counting
-
-    -- ** Labelling trees
-    -- $labelling
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Signatures
-import Control.Monad.Trans.Class
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-
--- ---------------------------------------------------------------------------
--- | A state monad parameterized by the type @s@ of the state to carry.
---
--- The 'return' function leaves the state unchanged, while @>>=@ uses
--- the final state of the first computation as the initial state of
--- the second.
-type State s = StateT s Identity
-
--- | Construct a state monad computation from a function.
--- (The inverse of 'runState'.)
-state :: (Monad m)
-      => (s -> (a, s))  -- ^pure state transformer
-      -> StateT s m a   -- ^equivalent state-passing computation
-state f = StateT (return . f)
-{-# INLINE state #-}
-
--- | Unwrap a state monad computation as a function.
--- (The inverse of 'state'.)
-runState :: State s a   -- ^state-passing computation to execute
-         -> s           -- ^initial state
-         -> (a, s)      -- ^return value and final state
-runState m = runIdentity . runStateT m
-{-# INLINE runState #-}
-
--- | Evaluate a state computation with the given initial state
--- and return the final value, discarding the final state.
---
--- * @'evalState' m s = 'fst' ('runState' m s)@
-evalState :: State s a  -- ^state-passing computation to execute
-          -> s          -- ^initial value
-          -> a          -- ^return value of the state computation
-evalState m s = fst (runState m s)
-{-# INLINE evalState #-}
-
--- | Evaluate a state computation with the given initial state
--- and return the final state, discarding the final value.
---
--- * @'execState' m s = 'snd' ('runState' m s)@
-execState :: State s a  -- ^state-passing computation to execute
-          -> s          -- ^initial value
-          -> s          -- ^final state
-execState m s = snd (runState m s)
-{-# INLINE execState #-}
-
--- | Map both the return value and final state of a computation using
--- the given function.
---
--- * @'runState' ('mapState' f m) = f . 'runState' m@
-mapState :: ((a, s) -> (b, s)) -> State s a -> State s b
-mapState f = mapStateT (Identity . f . runIdentity)
-{-# INLINE mapState #-}
-
--- | @'withState' f m@ executes action @m@ on a state modified by
--- applying @f@.
---
--- * @'withState' f m = 'modify' f >> m@
-withState :: (s -> s) -> State s a -> State s a
-withState = withStateT
-{-# INLINE withState #-}
-
--- ---------------------------------------------------------------------------
--- | A state transformer monad parameterized by:
---
---   * @s@ - The state.
---
---   * @m@ - The inner monad.
---
--- The 'return' function leaves the state unchanged, while @>>=@ uses
--- the final state of the first computation as the initial state of
--- the second.
-newtype StateT s m a = StateT { runStateT :: s -> m (a,s) }
-
--- | Evaluate a state computation with the given initial state
--- and return the final value, discarding the final state.
---
--- * @'evalStateT' m s = 'liftM' 'fst' ('runStateT' m s)@
-evalStateT :: (Monad m) => StateT s m a -> s -> m a
-evalStateT m s = do
-    (a, _) <- runStateT m s
-    return a
-{-# INLINE evalStateT #-}
-
--- | Evaluate a state computation with the given initial state
--- and return the final state, discarding the final value.
---
--- * @'execStateT' m s = 'liftM' 'snd' ('runStateT' m s)@
-execStateT :: (Monad m) => StateT s m a -> s -> m s
-execStateT m s = do
-    (_, s') <- runStateT m s
-    return s'
-{-# INLINE execStateT #-}
-
--- | Map both the return value and final state of a computation using
--- the given function.
---
--- * @'runStateT' ('mapStateT' f m) = f . 'runStateT' m@
-mapStateT :: (m (a, s) -> n (b, s)) -> StateT s m a -> StateT s n b
-mapStateT f m = StateT $ f . runStateT m
-{-# INLINE mapStateT #-}
-
--- | @'withStateT' f m@ executes action @m@ on a state modified by
--- applying @f@.
---
--- * @'withStateT' f m = 'modify' f >> m@
-withStateT :: (s -> s) -> StateT s m a -> StateT s m a
-withStateT f m = StateT $ runStateT m . f
-{-# INLINE withStateT #-}
-
-instance (Functor m) => Functor (StateT s m) where
-    fmap f m = StateT $ \ s ->
-        fmap (\ (a, s') -> (f a, s')) $ runStateT m s
-    {-# INLINE fmap #-}
-
-instance (Functor m, Monad m) => Applicative (StateT s m) where
-    pure a = StateT $ \ s -> return (a, s)
-    {-# INLINE pure #-}
-    StateT mf <*> StateT mx = StateT $ \ s -> do
-        (f, s') <- mf s
-        (x, s'') <- mx s'
-        return (f x, s'')
-    {-# INLINE (<*>) #-}
-    m *> k = m >>= \_ -> k
-    {-# INLINE (*>) #-}
-
-instance (Functor m, MonadPlus m) => Alternative (StateT s m) where
-    empty = StateT $ \ _ -> mzero
-    {-# INLINE empty #-}
-    StateT m <|> StateT n = StateT $ \ s -> m s `mplus` n s
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (StateT s m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = StateT $ \ s -> return (a, s)
-    {-# INLINE return #-}
-#endif
-    m >>= k  = StateT $ \ s -> do
-        (a, s') <- runStateT m s
-        runStateT (k a) s'
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail str = StateT $ \ _ -> fail str
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (StateT s m) where
-    fail str = StateT $ \ _ -> Fail.fail str
-    {-# INLINE fail #-}
-#endif
-
-instance (MonadPlus m) => MonadPlus (StateT s m) where
-    mzero       = StateT $ \ _ -> mzero
-    {-# INLINE mzero #-}
-    StateT m `mplus` StateT n = StateT $ \ s -> m s `mplus` n s
-    {-# INLINE mplus #-}
-
-instance (MonadFix m) => MonadFix (StateT s m) where
-    mfix f = StateT $ \ s -> mfix $ \ ~(a, _) -> runStateT (f a) s
-    {-# INLINE mfix #-}
-
-instance MonadTrans (StateT s) where
-    lift m = StateT $ \ s -> do
-        a <- m
-        return (a, s)
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (StateT s m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (StateT s m) where
-    contramap f m = StateT $ \s ->
-      contramap (\ (a, s') -> (f a, s')) $ runStateT m s
-    {-# INLINE contramap #-}
-#endif
-
--- | Fetch the current value of the state within the monad.
-get :: (Monad m) => StateT s m s
-get = state $ \ s -> (s, s)
-{-# INLINE get #-}
-
--- | @'put' s@ sets the state within the monad to @s@.
-put :: (Monad m) => s -> StateT s m ()
-put s = state $ \ _ -> ((), s)
-{-# INLINE put #-}
-
--- | @'modify' f@ is an action that updates the state to the result of
--- applying @f@ to the current state.
---
--- * @'modify' f = 'get' >>= ('put' . f)@
-modify :: (Monad m) => (s -> s) -> StateT s m ()
-modify f = state $ \ s -> ((), f s)
-{-# INLINE modify #-}
-
--- | A variant of 'modify' in which the computation is strict in the
--- new state.
---
--- * @'modify'' f = 'get' >>= (('$!') 'put' . f)@
-modify' :: (Monad m) => (s -> s) -> StateT s m ()
-modify' f = do
-    s <- get
-    put $! f s
-{-# INLINE modify' #-}
-
--- | Get a specific component of the state, using a projection function
--- supplied.
---
--- * @'gets' f = 'liftM' f 'get'@
-gets :: (Monad m) => (s -> a) -> StateT s m a
-gets f = state $ \ s -> (f s, s)
-{-# INLINE gets #-}
-
--- | Uniform lifting of a @callCC@ operation to the new monad.
--- This version rolls back to the original state on entering the
--- continuation.
-liftCallCC :: CallCC m (a,s) (b,s) -> CallCC (StateT s m) a b
-liftCallCC callCC f = StateT $ \ s ->
-    callCC $ \ c ->
-    runStateT (f (\ a -> StateT $ \ _ -> c (a, s))) s
-{-# INLINE liftCallCC #-}
-
--- | In-situ lifting of a @callCC@ operation to the new monad.
--- This version uses the current state on entering the continuation.
--- It does not satisfy the uniformity property (see "Control.Monad.Signatures").
-liftCallCC' :: CallCC m (a,s) (b,s) -> CallCC (StateT s m) a b
-liftCallCC' callCC f = StateT $ \ s ->
-    callCC $ \ c ->
-    runStateT (f (\ a -> StateT $ \ s' -> c (a, s'))) s
-{-# INLINE liftCallCC' #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a,s) -> Catch e (StateT s m) a
-liftCatch catchE m h =
-    StateT $ \ s -> runStateT m s `catchE` \ e -> runStateT (h e) s
-{-# INLINE liftCatch #-}
-
--- | Lift a @listen@ operation to the new monad.
-liftListen :: (Monad m) => Listen w m (a,s) -> Listen w (StateT s m) a
-liftListen listen m = StateT $ \ s -> do
-    ((a, s'), w) <- listen (runStateT m s)
-    return ((a, w), s')
-{-# INLINE liftListen #-}
-
--- | Lift a @pass@ operation to the new monad.
-liftPass :: (Monad m) => Pass w m (a,s) -> Pass w (StateT s m) a
-liftPass pass m = StateT $ \ s -> pass $ do
-    ((a, f), s') <- runStateT m s
-    return ((a, s'), f)
-{-# INLINE liftPass #-}
-
-{- $examples
-
-Parser from ParseLib with Hugs:
-
-> type Parser a = StateT String [] a
->    ==> StateT (String -> [(a,String)])
-
-For example, item can be written as:
-
-> item = do (x:xs) <- get
->        put xs
->        return x
->
-> type BoringState s a = StateT s Identity a
->      ==> StateT (s -> Identity (a,s))
->
-> type StateWithIO s a = StateT s IO a
->      ==> StateT (s -> IO (a,s))
->
-> type StateWithErr s a = StateT s Maybe a
->      ==> StateT (s -> Maybe (a,s))
-
--}
-
-{- $counting
-
-A function to increment a counter.
-Taken from the paper \"Generalising Monads to Arrows\",
-John Hughes (<http://www.cse.chalmers.se/~rjmh/>), November 1998:
-
-> tick :: State Int Int
-> tick = do n <- get
->           put (n+1)
->           return n
-
-Add one to the given number using the state monad:
-
-> plusOne :: Int -> Int
-> plusOne n = execState tick n
-
-A contrived addition example. Works only with positive numbers:
-
-> plus :: Int -> Int -> Int
-> plus n x = execState (sequence $ replicate n tick) x
-
--}
-
-{- $labelling
-
-An example from /The Craft of Functional Programming/, Simon
-Thompson (<http://www.cs.kent.ac.uk/people/staff/sjt/>),
-Addison-Wesley 1999: \"Given an arbitrary tree, transform it to a
-tree of integers in which the original elements are replaced by
-natural numbers, starting from 0.  The same element has to be
-replaced by the same number at every occurrence, and when we meet
-an as-yet-unvisited element we have to find a \'new\' number to match
-it with:\"
-
-> data Tree a = Nil | Node a (Tree a) (Tree a) deriving (Show, Eq)
-> type Table a = [a]
-
-> numberTree :: Eq a => Tree a -> State (Table a) (Tree Int)
-> numberTree Nil = return Nil
-> numberTree (Node x t1 t2) = do
->     num <- numberNode x
->     nt1 <- numberTree t1
->     nt2 <- numberTree t2
->     return (Node num nt1 nt2)
->   where
->     numberNode :: Eq a => a -> State (Table a) Int
->     numberNode x = do
->         table <- get
->         case elemIndex x table of
->             Nothing -> do
->                 put (table ++ [x])
->                 return (length table)
->             Just i -> return i
-
-numTree applies numberTree with an initial state:
-
-> numTree :: (Eq a) => Tree a -> Tree Int
-> numTree t = evalState (numberTree t) []
-
-> testTree = Node "Zero" (Node "One" (Node "Two" Nil Nil) (Node "One" (Node "Zero" Nil Nil) Nil)) Nil
-> numTree testTree => Node 0 (Node 1 (Node 2 Nil Nil) (Node 1 (Node 0 Nil Nil) Nil)) Nil
-
--}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer.hs
deleted file mode 100644
index f45f4d27687c..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer.hs
+++ /dev/null
@@ -1,25 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Writer
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The WriterT monad transformer.
--- This version builds its output lazily; for a constant-space version
--- with almost the same interface, see "Control.Monad.Trans.Writer.CPS".
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Writer (
-    module Control.Monad.Trans.Writer.Lazy
-  ) where
-
-import Control.Monad.Trans.Writer.Lazy
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/CPS.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/CPS.hs
deleted file mode 100644
index 28951016cf81..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/CPS.hs
+++ /dev/null
@@ -1,283 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Writer.CPS
--- Copyright   :  (c) Daniel Mendler 2016,
---                (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The strict 'WriterT' monad transformer, which adds collection of
--- outputs (such as a count or string output) to a given monad.
---
--- This monad transformer provides only limited access to the output
--- during the computation. For more general access, use
--- "Control.Monad.Trans.State" instead.
---
--- This version builds its output strictly and uses continuation-passing-style
--- to achieve constant space usage. This transformer can be used as a
--- drop-in replacement for "Control.Monad.Trans.Writer.Strict".
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Writer.CPS (
-    -- * The Writer monad
-    Writer,
-    writer,
-    runWriter,
-    execWriter,
-    mapWriter,
-    -- * The WriterT monad transformer
-    WriterT,
-    writerT,
-    runWriterT,
-    execWriterT,
-    mapWriterT,
-    -- * Writer operations
-    tell,
-    listen,
-    listens,
-    pass,
-    censor,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCatch,
-  ) where
-
-import Control.Applicative
-import Control.Monad
-import Control.Monad.Fix
-import Control.Monad.IO.Class
-import Control.Monad.Trans.Class
-import Control.Monad.Signatures
-import Data.Functor.Identity
-
-#if !(MIN_VERSION_base(4,8,0))
-import Data.Monoid
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-
--- ---------------------------------------------------------------------------
--- | A writer monad parameterized by the type @w@ of output to accumulate.
---
--- The 'return' function produces the output 'mempty', while '>>='
--- combines the outputs of the subcomputations using 'mappend'.
-type Writer w = WriterT w Identity
-
--- | Construct a writer computation from a (result, output) pair.
--- (The inverse of 'runWriter'.)
-writer :: (Monoid w, Monad m) => (a, w) -> WriterT w m a
-writer (a, w') = WriterT $ \ w ->
-    let wt = w `mappend` w' in wt `seq` return (a, wt)
-{-# INLINE writer #-}
-
--- | Unwrap a writer computation as a (result, output) pair.
--- (The inverse of 'writer'.)
-runWriter :: (Monoid w) => Writer w a -> (a, w)
-runWriter = runIdentity . runWriterT
-{-# INLINE runWriter #-}
-
--- | Extract the output from a writer computation.
---
--- * @'execWriter' m = 'snd' ('runWriter' m)@
-execWriter :: (Monoid w) => Writer w a -> w
-execWriter = runIdentity . execWriterT
-{-# INLINE execWriter #-}
-
--- | Map both the return value and output of a computation using
--- the given function.
---
--- * @'runWriter' ('mapWriter' f m) = f ('runWriter' m)@
-mapWriter :: (Monoid w, Monoid w') =>
-    ((a, w) -> (b, w')) -> Writer w a -> Writer w' b
-mapWriter f = mapWriterT (Identity . f . runIdentity)
-{-# INLINE mapWriter #-}
-
--- ---------------------------------------------------------------------------
--- | A writer monad parameterized by:
---
---   * @w@ - the output to accumulate.
---
---   * @m@ - The inner monad.
---
--- The 'return' function produces the output 'mempty', while '>>='
--- combines the outputs of the subcomputations using 'mappend'.
-
-newtype WriterT w m a = WriterT { unWriterT :: w -> m (a, w) }
-
--- | Construct a writer computation from a (result, output) computation.
--- (The inverse of 'runWriterT'.)
-writerT :: (Functor m, Monoid w) => m (a, w) -> WriterT w m a
-writerT f = WriterT $ \ w ->
-    (\ (a, w') -> let wt = w `mappend` w' in wt `seq` (a, wt)) <$> f
-{-# INLINE writerT #-}
-
--- | Unwrap a writer computation.
--- (The inverse of 'writerT'.)
-runWriterT :: (Monoid w) => WriterT w m a -> m (a, w)
-runWriterT m = unWriterT m mempty
-{-# INLINE runWriterT #-}
-
--- | Extract the output from a writer computation.
---
--- * @'execWriterT' m = 'liftM' 'snd' ('runWriterT' m)@
-execWriterT :: (Monad m, Monoid w) => WriterT w m a -> m w
-execWriterT m = do
-    (_, w) <- runWriterT m
-    return w
-{-# INLINE execWriterT #-}
-
--- | Map both the return value and output of a computation using
--- the given function.
---
--- * @'runWriterT' ('mapWriterT' f m) = f ('runWriterT' m)@
-mapWriterT :: (Monad n, Monoid w, Monoid w') =>
-    (m (a, w) -> n (b, w')) -> WriterT w m a -> WriterT w' n b
-mapWriterT f m = WriterT $ \ w -> do
-    (a, w') <- f (runWriterT m)
-    let wt = w `mappend` w'
-    wt `seq` return (a, wt)
-{-# INLINE mapWriterT #-}
-
-instance (Functor m) => Functor (WriterT w m) where
-    fmap f m = WriterT $ \ w -> (\ (a, w') -> (f a, w')) <$> unWriterT m w
-    {-# INLINE fmap #-}
-
-instance (Functor m, Monad m) => Applicative (WriterT w m) where
-    pure a = WriterT $ \ w -> return (a, w)
-    {-# INLINE pure #-}
-
-    WriterT mf <*> WriterT mx = WriterT $ \ w -> do
-        (f, w') <- mf w
-        (x, w'') <- mx w'
-        return (f x, w'')
-    {-# INLINE (<*>) #-}
-
-instance (Functor m, MonadPlus m) => Alternative (WriterT w m) where
-    empty = WriterT $ const mzero
-    {-# INLINE empty #-}
-
-    WriterT m <|> WriterT n = WriterT $ \ w -> m w `mplus` n w
-    {-# INLINE (<|>) #-}
-
-instance (Monad m) => Monad (WriterT w m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = WriterT $ \ w -> return (a, w)
-    {-# INLINE return #-}
-#endif
-
-    m >>= k = WriterT $ \ w -> do
-        (a, w') <- unWriterT m w
-        unWriterT (k a) w'
-    {-# INLINE (>>=) #-}
-
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = WriterT $ \ _ -> fail msg
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (WriterT w m) where
-    fail msg = WriterT $ \ _ -> Fail.fail msg
-    {-# INLINE fail #-}
-#endif
-
-instance (Functor m, MonadPlus m) => MonadPlus (WriterT w m) where
-    mzero = empty
-    {-# INLINE mzero #-}
-    mplus = (<|>)
-    {-# INLINE mplus #-}
-
-instance (MonadFix m) => MonadFix (WriterT w m) where
-    mfix f = WriterT $ \ w -> mfix $ \ ~(a, _) -> unWriterT (f a) w
-    {-# INLINE mfix #-}
-
-instance MonadTrans (WriterT w) where
-    lift m = WriterT $ \ w -> do
-        a <- m
-        return (a, w)
-    {-# INLINE lift #-}
-
-instance (MonadIO m) => MonadIO (WriterT w m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
--- | @'tell' w@ is an action that produces the output @w@.
-tell :: (Monoid w, Monad m) => w -> WriterT w m ()
-tell w = writer ((), w)
-{-# INLINE tell #-}
-
--- | @'listen' m@ is an action that executes the action @m@ and adds its
--- output to the value of the computation.
---
--- * @'runWriterT' ('listen' m) = 'liftM' (\\ (a, w) -> ((a, w), w)) ('runWriterT' m)@
-listen :: (Monoid w, Monad m) => WriterT w m a -> WriterT w m (a, w)
-listen = listens id
-{-# INLINE listen #-}
-
--- | @'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.
---
--- * @'listens' f m = 'liftM' (id *** f) ('listen' m)@
---
--- * @'runWriterT' ('listens' f m) = 'liftM' (\\ (a, w) -> ((a, f w), w)) ('runWriterT' m)@
-listens :: (Monoid w, Monad m) =>
-    (w -> b) -> WriterT w m a -> WriterT w m (a, b)
-listens f m = WriterT $ \ w -> do
-    (a, w') <- runWriterT m
-    let wt = w `mappend` w'
-    wt `seq` return ((a, f w'), wt)
-{-# INLINE listens #-}
-
--- | @'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.
---
--- * @'runWriterT' ('pass' m) = 'liftM' (\\ ((a, f), w) -> (a, f w)) ('runWriterT' m)@
-pass :: (Monoid w, Monoid w', Monad m) =>
-    WriterT w m (a, w -> w') -> WriterT w' m a
-pass m = WriterT $ \ w -> do
-    ((a, f), w') <- runWriterT m
-    let wt = w `mappend` f w'
-    wt `seq` return (a, wt)
-{-# INLINE pass #-}
-
--- | @'censor' f m@ is an action that executes the action @m@ and
--- applies the function @f@ to its output, leaving the return value
--- unchanged.
---
--- * @'censor' f m = 'pass' ('liftM' (\\ x -> (x,f)) m)@
---
--- * @'runWriterT' ('censor' f m) = 'liftM' (\\ (a, w) -> (a, f w)) ('runWriterT' m)@
-censor :: (Monoid w, Monad m) => (w -> w) -> WriterT w m a -> WriterT w m a
-censor f m = WriterT $ \ w -> do
-    (a, w') <- runWriterT m
-    let wt = w `mappend` f w'
-    wt `seq` return (a, wt)
-{-# INLINE censor #-}
-
--- | Uniform lifting of a @callCC@ operation to the new monad.
--- This version rolls back to the original state on entering the
--- continuation.
-liftCallCC :: CallCC m (a, w) (b, w) -> CallCC (WriterT w m) a b
-liftCallCC callCC f = WriterT $ \ w ->
-    callCC $ \ c -> unWriterT (f (\ a -> WriterT $ \ _ -> c (a, w))) w
-{-# INLINE liftCallCC #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a, w) -> Catch e (WriterT w m) a
-liftCatch catchE m h = WriterT $ \ w ->
-    unWriterT m w `catchE` \ e -> unWriterT (h e) w
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/Lazy.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/Lazy.hs
deleted file mode 100644
index d12b0e7d583c..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/Lazy.hs
+++ /dev/null
@@ -1,313 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Writer.Lazy
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The lazy 'WriterT' monad transformer, which adds collection of
--- outputs (such as a count or string output) to a given monad.
---
--- This monad transformer provides only limited access to the output
--- during the computation.  For more general access, use
--- "Control.Monad.Trans.State" instead.
---
--- This version builds its output lazily; for a constant-space version
--- with almost the same interface, see "Control.Monad.Trans.Writer.CPS".
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Writer.Lazy (
-    -- * The Writer monad
-    Writer,
-    writer,
-    runWriter,
-    execWriter,
-    mapWriter,
-    -- * The WriterT monad transformer
-    WriterT(..),
-    execWriterT,
-    mapWriterT,
-    -- * Writer operations
-    tell,
-    listen,
-    listens,
-    pass,
-    censor,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCatch,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Trans.Class
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-import Control.Monad.Signatures
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith))
-#endif
-import Data.Foldable
-import Data.Monoid
-import Data.Traversable (Traversable(traverse))
-import Prelude hiding (null, length)
-
--- ---------------------------------------------------------------------------
--- | A writer monad parameterized by the type @w@ of output to accumulate.
---
--- The 'return' function produces the output 'mempty', while @>>=@
--- combines the outputs of the subcomputations using 'mappend'.
-type Writer w = WriterT w Identity
-
--- | Construct a writer computation from a (result, output) pair.
--- (The inverse of 'runWriter'.)
-writer :: (Monad m) => (a, w) -> WriterT w m a
-writer = WriterT . return
-{-# INLINE writer #-}
-
--- | Unwrap a writer computation as a (result, output) pair.
--- (The inverse of 'writer'.)
-runWriter :: Writer w a -> (a, w)
-runWriter = runIdentity . runWriterT
-{-# INLINE runWriter #-}
-
--- | Extract the output from a writer computation.
---
--- * @'execWriter' m = 'snd' ('runWriter' m)@
-execWriter :: Writer w a -> w
-execWriter m = snd (runWriter m)
-{-# INLINE execWriter #-}
-
--- | Map both the return value and output of a computation using
--- the given function.
---
--- * @'runWriter' ('mapWriter' f m) = f ('runWriter' m)@
-mapWriter :: ((a, w) -> (b, w')) -> Writer w a -> Writer w' b
-mapWriter f = mapWriterT (Identity . f . runIdentity)
-{-# INLINE mapWriter #-}
-
--- ---------------------------------------------------------------------------
--- | A writer monad parameterized by:
---
---   * @w@ - the output to accumulate.
---
---   * @m@ - The inner monad.
---
--- The 'return' function produces the output 'mempty', while @>>=@
--- combines the outputs of the subcomputations using 'mappend'.
-newtype WriterT w m a = WriterT { runWriterT :: m (a, w) }
-
-instance (Eq w, Eq1 m) => Eq1 (WriterT w m) where
-    liftEq eq (WriterT m1) (WriterT m2) = liftEq (liftEq2 eq (==)) m1 m2
-    {-# INLINE liftEq #-}
-
-instance (Ord w, Ord1 m) => Ord1 (WriterT w m) where
-    liftCompare comp (WriterT m1) (WriterT m2) =
-        liftCompare (liftCompare2 comp compare) m1 m2
-    {-# INLINE liftCompare #-}
-
-instance (Read w, Read1 m) => Read1 (WriterT w m) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp' rl') "WriterT" WriterT
-      where
-        rp' = liftReadsPrec2 rp rl readsPrec readList
-        rl' = liftReadList2 rp rl readsPrec readList
-
-instance (Show w, Show1 m) => Show1 (WriterT w m) where
-    liftShowsPrec sp sl d (WriterT m) =
-        showsUnaryWith (liftShowsPrec sp' sl') "WriterT" d m
-      where
-        sp' = liftShowsPrec2 sp sl showsPrec showList
-        sl' = liftShowList2 sp sl showsPrec showList
-
-instance (Eq w, Eq1 m, Eq a) => Eq (WriterT w m a) where (==) = eq1
-instance (Ord w, Ord1 m, Ord a) => Ord (WriterT w m a) where compare = compare1
-instance (Read w, Read1 m, Read a) => Read (WriterT w m a) where
-    readsPrec = readsPrec1
-instance (Show w, Show1 m, Show a) => Show (WriterT w m a) where
-    showsPrec = showsPrec1
-
--- | Extract the output from a writer computation.
---
--- * @'execWriterT' m = 'liftM' 'snd' ('runWriterT' m)@
-execWriterT :: (Monad m) => WriterT w m a -> m w
-execWriterT m = do
-    ~(_, w) <- runWriterT m
-    return w
-{-# INLINE execWriterT #-}
-
--- | Map both the return value and output of a computation using
--- the given function.
---
--- * @'runWriterT' ('mapWriterT' f m) = f ('runWriterT' m)@
-mapWriterT :: (m (a, w) -> n (b, w')) -> WriterT w m a -> WriterT w' n b
-mapWriterT f m = WriterT $ f (runWriterT m)
-{-# INLINE mapWriterT #-}
-
-instance (Functor m) => Functor (WriterT w m) where
-    fmap f = mapWriterT $ fmap $ \ ~(a, w) -> (f a, w)
-    {-# INLINE fmap #-}
-
-instance (Foldable f) => Foldable (WriterT w f) where
-    foldMap f = foldMap (f . fst) . runWriterT
-    {-# INLINE foldMap #-}
-#if MIN_VERSION_base(4,8,0)
-    null (WriterT t) = null t
-    length (WriterT t) = length t
-#endif
-
-instance (Traversable f) => Traversable (WriterT w f) where
-    traverse f = fmap WriterT . traverse f' . runWriterT where
-       f' (a, b) = fmap (\ c -> (c, b)) (f a)
-    {-# INLINE traverse #-}
-
-instance (Monoid w, Applicative m) => Applicative (WriterT w m) where
-    pure a  = WriterT $ pure (a, mempty)
-    {-# INLINE pure #-}
-    f <*> v = WriterT $ liftA2 k (runWriterT f) (runWriterT v)
-      where k ~(a, w) ~(b, w') = (a b, w `mappend` w')
-    {-# INLINE (<*>) #-}
-
-instance (Monoid w, Alternative m) => Alternative (WriterT w m) where
-    empty   = WriterT empty
-    {-# INLINE empty #-}
-    m <|> n = WriterT $ runWriterT m <|> runWriterT n
-    {-# INLINE (<|>) #-}
-
-instance (Monoid w, Monad m) => Monad (WriterT w m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = writer (a, mempty)
-    {-# INLINE return #-}
-#endif
-    m >>= k  = WriterT $ do
-        ~(a, w)  <- runWriterT m
-        ~(b, w') <- runWriterT (k a)
-        return (b, w `mappend` w')
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = WriterT $ fail msg
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Monoid w, Fail.MonadFail m) => Fail.MonadFail (WriterT w m) where
-    fail msg = WriterT $ Fail.fail msg
-    {-# INLINE fail #-}
-#endif
-
-instance (Monoid w, MonadPlus m) => MonadPlus (WriterT w m) where
-    mzero       = WriterT mzero
-    {-# INLINE mzero #-}
-    m `mplus` n = WriterT $ runWriterT m `mplus` runWriterT n
-    {-# INLINE mplus #-}
-
-instance (Monoid w, MonadFix m) => MonadFix (WriterT w m) where
-    mfix m = WriterT $ mfix $ \ ~(a, _) -> runWriterT (m a)
-    {-# INLINE mfix #-}
-
-instance (Monoid w) => MonadTrans (WriterT w) where
-    lift m = WriterT $ do
-        a <- m
-        return (a, mempty)
-    {-# INLINE lift #-}
-
-instance (Monoid w, MonadIO m) => MonadIO (WriterT w m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,4,0)
-instance (Monoid w, MonadZip m) => MonadZip (WriterT w m) where
-    mzipWith f (WriterT x) (WriterT y) = WriterT $
-        mzipWith (\ ~(a, w) ~(b, w') -> (f a b, w `mappend` w')) x y
-    {-# INLINE mzipWith #-}
-#endif
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (WriterT w m) where
-    contramap f = mapWriterT $ contramap $ \ ~(a, w) -> (f a, w)
-    {-# INLINE contramap #-}
-#endif
-
--- | @'tell' w@ is an action that produces the output @w@.
-tell :: (Monad m) => w -> WriterT w m ()
-tell w = writer ((), w)
-{-# INLINE tell #-}
-
--- | @'listen' m@ is an action that executes the action @m@ and adds its
--- output to the value of the computation.
---
--- * @'runWriterT' ('listen' m) = 'liftM' (\\ (a, w) -> ((a, w), w)) ('runWriterT' m)@
-listen :: (Monad m) => WriterT w m a -> WriterT w m (a, w)
-listen m = WriterT $ do
-    ~(a, w) <- runWriterT m
-    return ((a, w), w)
-{-# INLINE listen #-}
-
--- | @'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.
---
--- * @'listens' f m = 'liftM' (id *** f) ('listen' m)@
---
--- * @'runWriterT' ('listens' f m) = 'liftM' (\\ (a, w) -> ((a, f w), w)) ('runWriterT' m)@
-listens :: (Monad m) => (w -> b) -> WriterT w m a -> WriterT w m (a, b)
-listens f m = WriterT $ do
-    ~(a, w) <- runWriterT m
-    return ((a, f w), w)
-{-# INLINE listens #-}
-
--- | @'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.
---
--- * @'runWriterT' ('pass' m) = 'liftM' (\\ ((a, f), w) -> (a, f w)) ('runWriterT' m)@
-pass :: (Monad m) => WriterT w m (a, w -> w) -> WriterT w m a
-pass m = WriterT $ do
-    ~((a, f), w) <- runWriterT m
-    return (a, f w)
-{-# INLINE pass #-}
-
--- | @'censor' f m@ is an action that executes the action @m@ and
--- applies the function @f@ to its output, leaving the return value
--- unchanged.
---
--- * @'censor' f m = 'pass' ('liftM' (\\ x -> (x,f)) m)@
---
--- * @'runWriterT' ('censor' f m) = 'liftM' (\\ (a, w) -> (a, f w)) ('runWriterT' m)@
-censor :: (Monad m) => (w -> w) -> WriterT w m a -> WriterT w m a
-censor f m = WriterT $ do
-    ~(a, w) <- runWriterT m
-    return (a, f w)
-{-# INLINE censor #-}
-
--- | Lift a @callCC@ operation to the new monad.
-liftCallCC :: (Monoid w) => CallCC m (a,w) (b,w) -> CallCC (WriterT w m) a b
-liftCallCC callCC f = WriterT $
-    callCC $ \ c ->
-    runWriterT (f (\ a -> WriterT $ c (a, mempty)))
-{-# INLINE liftCallCC #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a,w) -> Catch e (WriterT w m) a
-liftCatch catchE m h =
-    WriterT $ runWriterT m `catchE` \ e -> runWriterT (h e)
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/Strict.hs b/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/Strict.hs
deleted file mode 100644
index f39862c02044..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Control/Monad/Trans/Writer/Strict.hs
+++ /dev/null
@@ -1,316 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.Trans.Writer.Strict
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The strict 'WriterT' monad transformer, which adds collection of
--- outputs (such as a count or string output) to a given monad.
---
--- This monad transformer provides only limited access to the output
--- during the computation.  For more general access, use
--- "Control.Monad.Trans.State" instead.
---
--- This version builds its output strictly; for a lazy version with
--- the same interface, see "Control.Monad.Trans.Writer.Lazy".
--- Although the output is built strictly, it is not possible to
--- achieve constant space behaviour with this transformer: for that,
--- use "Control.Monad.Trans.Writer.CPS" instead.
------------------------------------------------------------------------------
-
-module Control.Monad.Trans.Writer.Strict (
-    -- * The Writer monad
-    Writer,
-    writer,
-    runWriter,
-    execWriter,
-    mapWriter,
-    -- * The WriterT monad transformer
-    WriterT(..),
-    execWriterT,
-    mapWriterT,
-    -- * Writer operations
-    tell,
-    listen,
-    listens,
-    pass,
-    censor,
-    -- * Lifting other operations
-    liftCallCC,
-    liftCatch,
-  ) where
-
-import Control.Monad.IO.Class
-import Control.Monad.Trans.Class
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Functor.Identity
-
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Control.Monad.Fix
-import Control.Monad.Signatures
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith))
-#endif
-import Data.Foldable
-import Data.Monoid
-import Data.Traversable (Traversable(traverse))
-import Prelude hiding (null, length)
-
--- ---------------------------------------------------------------------------
--- | A writer monad parameterized by the type @w@ of output to accumulate.
---
--- The 'return' function produces the output 'mempty', while @>>=@
--- combines the outputs of the subcomputations using 'mappend'.
-type Writer w = WriterT w Identity
-
--- | Construct a writer computation from a (result, output) pair.
--- (The inverse of 'runWriter'.)
-writer :: (Monad m) => (a, w) -> WriterT w m a
-writer = WriterT . return
-{-# INLINE writer #-}
-
--- | Unwrap a writer computation as a (result, output) pair.
--- (The inverse of 'writer'.)
-runWriter :: Writer w a -> (a, w)
-runWriter = runIdentity . runWriterT
-{-# INLINE runWriter #-}
-
--- | Extract the output from a writer computation.
---
--- * @'execWriter' m = 'snd' ('runWriter' m)@
-execWriter :: Writer w a -> w
-execWriter m = snd (runWriter m)
-{-# INLINE execWriter #-}
-
--- | Map both the return value and output of a computation using
--- the given function.
---
--- * @'runWriter' ('mapWriter' f m) = f ('runWriter' m)@
-mapWriter :: ((a, w) -> (b, w')) -> Writer w a -> Writer w' b
-mapWriter f = mapWriterT (Identity . f . runIdentity)
-{-# INLINE mapWriter #-}
-
--- ---------------------------------------------------------------------------
--- | A writer monad parameterized by:
---
---   * @w@ - the output to accumulate.
---
---   * @m@ - The inner monad.
---
--- The 'return' function produces the output 'mempty', while @>>=@
--- combines the outputs of the subcomputations using 'mappend'.
-newtype WriterT w m a = WriterT { runWriterT :: m (a, w) }
-
-instance (Eq w, Eq1 m) => Eq1 (WriterT w m) where
-    liftEq eq (WriterT m1) (WriterT m2) = liftEq (liftEq2 eq (==)) m1 m2
-    {-# INLINE liftEq #-}
-
-instance (Ord w, Ord1 m) => Ord1 (WriterT w m) where
-    liftCompare comp (WriterT m1) (WriterT m2) =
-        liftCompare (liftCompare2 comp compare) m1 m2
-    {-# INLINE liftCompare #-}
-
-instance (Read w, Read1 m) => Read1 (WriterT w m) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp' rl') "WriterT" WriterT
-      where
-        rp' = liftReadsPrec2 rp rl readsPrec readList
-        rl' = liftReadList2 rp rl readsPrec readList
-
-instance (Show w, Show1 m) => Show1 (WriterT w m) where
-    liftShowsPrec sp sl d (WriterT m) =
-        showsUnaryWith (liftShowsPrec sp' sl') "WriterT" d m
-      where
-        sp' = liftShowsPrec2 sp sl showsPrec showList
-        sl' = liftShowList2 sp sl showsPrec showList
-
-instance (Eq w, Eq1 m, Eq a) => Eq (WriterT w m a) where (==) = eq1
-instance (Ord w, Ord1 m, Ord a) => Ord (WriterT w m a) where compare = compare1
-instance (Read w, Read1 m, Read a) => Read (WriterT w m a) where
-    readsPrec = readsPrec1
-instance (Show w, Show1 m, Show a) => Show (WriterT w m a) where
-    showsPrec = showsPrec1
-
--- | Extract the output from a writer computation.
---
--- * @'execWriterT' m = 'liftM' 'snd' ('runWriterT' m)@
-execWriterT :: (Monad m) => WriterT w m a -> m w
-execWriterT m = do
-    (_, w) <- runWriterT m
-    return w
-{-# INLINE execWriterT #-}
-
--- | Map both the return value and output of a computation using
--- the given function.
---
--- * @'runWriterT' ('mapWriterT' f m) = f ('runWriterT' m)@
-mapWriterT :: (m (a, w) -> n (b, w')) -> WriterT w m a -> WriterT w' n b
-mapWriterT f m = WriterT $ f (runWriterT m)
-{-# INLINE mapWriterT #-}
-
-instance (Functor m) => Functor (WriterT w m) where
-    fmap f = mapWriterT $ fmap $ \ (a, w) -> (f a, w)
-    {-# INLINE fmap #-}
-
-instance (Foldable f) => Foldable (WriterT w f) where
-    foldMap f = foldMap (f . fst) . runWriterT
-    {-# INLINE foldMap #-}
-#if MIN_VERSION_base(4,8,0)
-    null (WriterT t) = null t
-    length (WriterT t) = length t
-#endif
-
-instance (Traversable f) => Traversable (WriterT w f) where
-    traverse f = fmap WriterT . traverse f' . runWriterT where
-       f' (a, b) = fmap (\ c -> (c, b)) (f a)
-    {-# INLINE traverse #-}
-
-instance (Monoid w, Applicative m) => Applicative (WriterT w m) where
-    pure a  = WriterT $ pure (a, mempty)
-    {-# INLINE pure #-}
-    f <*> v = WriterT $ liftA2 k (runWriterT f) (runWriterT v)
-      where k (a, w) (b, w') = (a b, w `mappend` w')
-    {-# INLINE (<*>) #-}
-
-instance (Monoid w, Alternative m) => Alternative (WriterT w m) where
-    empty   = WriterT empty
-    {-# INLINE empty #-}
-    m <|> n = WriterT $ runWriterT m <|> runWriterT n
-    {-# INLINE (<|>) #-}
-
-instance (Monoid w, Monad m) => Monad (WriterT w m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = writer (a, mempty)
-    {-# INLINE return #-}
-#endif
-    m >>= k  = WriterT $ do
-        (a, w)  <- runWriterT m
-        (b, w') <- runWriterT (k a)
-        return (b, w `mappend` w')
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = WriterT $ fail msg
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Monoid w, Fail.MonadFail m) => Fail.MonadFail (WriterT w m) where
-    fail msg = WriterT $ Fail.fail msg
-    {-# INLINE fail #-}
-#endif
-
-instance (Monoid w, MonadPlus m) => MonadPlus (WriterT w m) where
-    mzero       = WriterT mzero
-    {-# INLINE mzero #-}
-    m `mplus` n = WriterT $ runWriterT m `mplus` runWriterT n
-    {-# INLINE mplus #-}
-
-instance (Monoid w, MonadFix m) => MonadFix (WriterT w m) where
-    mfix m = WriterT $ mfix $ \ ~(a, _) -> runWriterT (m a)
-    {-# INLINE mfix #-}
-
-instance (Monoid w) => MonadTrans (WriterT w) where
-    lift m = WriterT $ do
-        a <- m
-        return (a, mempty)
-    {-# INLINE lift #-}
-
-instance (Monoid w, MonadIO m) => MonadIO (WriterT w m) where
-    liftIO = lift . liftIO
-    {-# INLINE liftIO #-}
-
-#if MIN_VERSION_base(4,4,0)
-instance (Monoid w, MonadZip m) => MonadZip (WriterT w m) where
-    mzipWith f (WriterT x) (WriterT y) = WriterT $
-        mzipWith (\ (a, w) (b, w') -> (f a b, w `mappend` w')) x y
-    {-# INLINE mzipWith #-}
-#endif
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant m => Contravariant (WriterT w m) where
-    contramap f = mapWriterT $ contramap $ \ (a, w) -> (f a, w)
-    {-# INLINE contramap #-}
-#endif
-
--- | @'tell' w@ is an action that produces the output @w@.
-tell :: (Monad m) => w -> WriterT w m ()
-tell w = writer ((), w)
-{-# INLINE tell #-}
-
--- | @'listen' m@ is an action that executes the action @m@ and adds its
--- output to the value of the computation.
---
--- * @'runWriterT' ('listen' m) = 'liftM' (\\ (a, w) -> ((a, w), w)) ('runWriterT' m)@
-listen :: (Monad m) => WriterT w m a -> WriterT w m (a, w)
-listen m = WriterT $ do
-    (a, w) <- runWriterT m
-    return ((a, w), w)
-{-# INLINE listen #-}
-
--- | @'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.
---
--- * @'listens' f m = 'liftM' (id *** f) ('listen' m)@
---
--- * @'runWriterT' ('listens' f m) = 'liftM' (\\ (a, w) -> ((a, f w), w)) ('runWriterT' m)@
-listens :: (Monad m) => (w -> b) -> WriterT w m a -> WriterT w m (a, b)
-listens f m = WriterT $ do
-    (a, w) <- runWriterT m
-    return ((a, f w), w)
-{-# INLINE listens #-}
-
--- | @'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.
---
--- * @'runWriterT' ('pass' m) = 'liftM' (\\ ((a, f), w) -> (a, f w)) ('runWriterT' m)@
-pass :: (Monad m) => WriterT w m (a, w -> w) -> WriterT w m a
-pass m = WriterT $ do
-    ((a, f), w) <- runWriterT m
-    return (a, f w)
-{-# INLINE pass #-}
-
--- | @'censor' f m@ is an action that executes the action @m@ and
--- applies the function @f@ to its output, leaving the return value
--- unchanged.
---
--- * @'censor' f m = 'pass' ('liftM' (\\ x -> (x,f)) m)@
---
--- * @'runWriterT' ('censor' f m) = 'liftM' (\\ (a, w) -> (a, f w)) ('runWriterT' m)@
-censor :: (Monad m) => (w -> w) -> WriterT w m a -> WriterT w m a
-censor f m = WriterT $ do
-    (a, w) <- runWriterT m
-    return (a, f w)
-{-# INLINE censor #-}
-
--- | Lift a @callCC@ operation to the new monad.
-liftCallCC :: (Monoid w) => CallCC m (a,w) (b,w) -> CallCC (WriterT w m) a b
-liftCallCC callCC f = WriterT $
-    callCC $ \ c ->
-    runWriterT (f (\ a -> WriterT $ c (a, mempty)))
-{-# INLINE liftCallCC #-}
-
--- | Lift a @catchE@ operation to the new monad.
-liftCatch :: Catch e m (a,w) -> Catch e (WriterT w m) a
-liftCatch catchE m h =
-    WriterT $ runWriterT m `catchE` \ e -> runWriterT (h e)
-{-# INLINE liftCatch #-}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Data/Functor/Constant.hs b/third_party/bazel/rules_haskell/examples/transformers/Data/Functor/Constant.hs
deleted file mode 100644
index 9c0b8d42dcad..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Data/Functor/Constant.hs
+++ /dev/null
@@ -1,152 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Data.Functor.Constant
--- Copyright   :  (c) Ross Paterson 2010
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The constant functor.
------------------------------------------------------------------------------
-
-module Data.Functor.Constant (
-    Constant(..),
-  ) where
-
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-
-import Control.Applicative
-import Data.Foldable
-import Data.Monoid (Monoid(..))
-import Data.Traversable (Traversable(traverse))
-#if MIN_VERSION_base(4,8,0)
-import Data.Bifunctor (Bifunctor(..))
-#endif
-#if MIN_VERSION_base(4,9,0)
-import Data.Semigroup (Semigroup(..))
-#endif
-#if MIN_VERSION_base(4,10,0)
-import Data.Bifoldable (Bifoldable(..))
-import Data.Bitraversable (Bitraversable(..))
-#endif
-import Prelude hiding (null, length)
-
--- | Constant functor.
-newtype Constant a b = Constant { getConstant :: a }
-    deriving (Eq, Ord)
-
--- These instances would be equivalent to the derived instances of the
--- newtype if the field were removed.
-
-instance (Read a) => Read (Constant a b) where
-    readsPrec = readsData $
-         readsUnaryWith readsPrec "Constant" Constant
-
-instance (Show a) => Show (Constant a b) where
-    showsPrec d (Constant x) = showsUnaryWith showsPrec "Constant" d x
-
--- Instances of lifted Prelude classes
-
-instance Eq2 Constant where
-    liftEq2 eq _ (Constant x) (Constant y) = eq x y
-    {-# INLINE liftEq2 #-}
-
-instance Ord2 Constant where
-    liftCompare2 comp _ (Constant x) (Constant y) = comp x y
-    {-# INLINE liftCompare2 #-}
-
-instance Read2 Constant where
-    liftReadsPrec2 rp _ _ _ = readsData $
-         readsUnaryWith rp "Constant" Constant
-
-instance Show2 Constant where
-    liftShowsPrec2 sp _ _ _ d (Constant x) = showsUnaryWith sp "Constant" d x
-
-instance (Eq a) => Eq1 (Constant a) where
-    liftEq = liftEq2 (==)
-    {-# INLINE liftEq #-}
-instance (Ord a) => Ord1 (Constant a) where
-    liftCompare = liftCompare2 compare
-    {-# INLINE liftCompare #-}
-instance (Read a) => Read1 (Constant a) where
-    liftReadsPrec = liftReadsPrec2 readsPrec readList
-    {-# INLINE liftReadsPrec #-}
-instance (Show a) => Show1 (Constant a) where
-    liftShowsPrec = liftShowsPrec2 showsPrec showList
-    {-# INLINE liftShowsPrec #-}
-
-instance Functor (Constant a) where
-    fmap _ (Constant x) = Constant x
-    {-# INLINE fmap #-}
-
-instance Foldable (Constant a) where
-    foldMap _ (Constant _) = mempty
-    {-# INLINE foldMap #-}
-#if MIN_VERSION_base(4,8,0)
-    null (Constant _) = True
-    length (Constant _) = 0
-#endif
-
-instance Traversable (Constant a) where
-    traverse _ (Constant x) = pure (Constant x)
-    {-# INLINE traverse #-}
-
-#if MIN_VERSION_base(4,9,0)
-instance (Semigroup a) => Semigroup (Constant a b) where
-    Constant x <> Constant y = Constant (x <> y)
-    {-# INLINE (<>) #-}
-#endif
-
-instance (Monoid a) => Applicative (Constant a) where
-    pure _ = Constant mempty
-    {-# INLINE pure #-}
-    Constant x <*> Constant y = Constant (x `mappend` y)
-    {-# INLINE (<*>) #-}
-
-instance (Monoid a) => Monoid (Constant a b) where
-    mempty = Constant mempty
-    {-# INLINE mempty #-}
-#if !MIN_VERSION_base(4,11,0)
-    -- From base-4.11, Monoid(mappend) defaults to Semigroup((<>))
-    Constant x `mappend` Constant y = Constant (x `mappend` y)
-    {-# INLINE mappend #-}
-#endif
-
-#if MIN_VERSION_base(4,8,0)
-instance Bifunctor Constant where
-    first f (Constant x) = Constant (f x)
-    {-# INLINE first #-}
-    second _ (Constant x) = Constant x
-    {-# INLINE second #-}
-#endif
-
-#if MIN_VERSION_base(4,10,0)
-instance Bifoldable Constant where
-    bifoldMap f _ (Constant a) = f a
-    {-# INLINE bifoldMap #-}
-
-instance Bitraversable Constant where
-    bitraverse f _ (Constant a) = Constant <$> f a
-    {-# INLINE bitraverse #-}
-#endif
-
-#if MIN_VERSION_base(4,12,0)
-instance Contravariant (Constant a) where
-    contramap _ (Constant a) = Constant a
-    {-# INLINE contramap #-}
-#endif
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Data/Functor/Reverse.hs b/third_party/bazel/rules_haskell/examples/transformers/Data/Functor/Reverse.hs
deleted file mode 100644
index 5d8c41fa15c1..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Data/Functor/Reverse.hs
+++ /dev/null
@@ -1,143 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 710
-{-# LANGUAGE AutoDeriveTypeable #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Data.Functor.Reverse
--- Copyright   :  (c) Russell O'Connor 2009
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Making functors whose elements are notionally in the reverse order
--- from the original functor.
------------------------------------------------------------------------------
-
-module Data.Functor.Reverse (
-    Reverse(..),
-  ) where
-
-import Control.Applicative.Backwards
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-
-import Prelude hiding (foldr, foldr1, foldl, foldl1, null, length)
-import Control.Applicative
-import Control.Monad
-#if MIN_VERSION_base(4,9,0)
-import qualified Control.Monad.Fail as Fail
-#endif
-import Data.Foldable
-import Data.Traversable
-import Data.Monoid
-
--- | The same functor, but with 'Foldable' and 'Traversable' instances
--- that process the elements in the reverse order.
-newtype Reverse f a = Reverse { getReverse :: f a }
-
-instance (Eq1 f) => Eq1 (Reverse f) where
-    liftEq eq (Reverse x) (Reverse y) = liftEq eq x y
-    {-# INLINE liftEq #-}
-
-instance (Ord1 f) => Ord1 (Reverse f) where
-    liftCompare comp (Reverse x) (Reverse y) = liftCompare comp x y
-    {-# INLINE liftCompare #-}
-
-instance (Read1 f) => Read1 (Reverse f) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp rl) "Reverse" Reverse
-
-instance (Show1 f) => Show1 (Reverse f) where
-    liftShowsPrec sp sl d (Reverse x) =
-        showsUnaryWith (liftShowsPrec sp sl) "Reverse" d x
-
-instance (Eq1 f, Eq a) => Eq (Reverse f a) where (==) = eq1
-instance (Ord1 f, Ord a) => Ord (Reverse f a) where compare = compare1
-instance (Read1 f, Read a) => Read (Reverse f a) where readsPrec = readsPrec1
-instance (Show1 f, Show a) => Show (Reverse f a) where showsPrec = showsPrec1
-
--- | Derived instance.
-instance (Functor f) => Functor (Reverse f) where
-    fmap f (Reverse a) = Reverse (fmap f a)
-    {-# INLINE fmap #-}
-
--- | Derived instance.
-instance (Applicative f) => Applicative (Reverse f) where
-    pure a = Reverse (pure a)
-    {-# INLINE pure #-}
-    Reverse f <*> Reverse a = Reverse (f <*> a)
-    {-# INLINE (<*>) #-}
-
--- | Derived instance.
-instance (Alternative f) => Alternative (Reverse f) where
-    empty = Reverse empty
-    {-# INLINE empty #-}
-    Reverse x <|> Reverse y = Reverse (x <|> y)
-    {-# INLINE (<|>) #-}
-
--- | Derived instance.
-instance (Monad m) => Monad (Reverse m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = Reverse (return a)
-    {-# INLINE return #-}
-#endif
-    m >>= f = Reverse (getReverse m >>= getReverse . f)
-    {-# INLINE (>>=) #-}
-#if !(MIN_VERSION_base(4,13,0))
-    fail msg = Reverse (fail msg)
-    {-# INLINE fail #-}
-#endif
-
-#if MIN_VERSION_base(4,9,0)
-instance (Fail.MonadFail m) => Fail.MonadFail (Reverse m) where
-    fail msg = Reverse (Fail.fail msg)
-    {-# INLINE fail #-}
-#endif
-
--- | Derived instance.
-instance (MonadPlus m) => MonadPlus (Reverse m) where
-    mzero = Reverse mzero
-    {-# INLINE mzero #-}
-    Reverse x `mplus` Reverse y = Reverse (x `mplus` y)
-    {-# INLINE mplus #-}
-
--- | Fold from right to left.
-instance (Foldable f) => Foldable (Reverse f) where
-    foldMap f (Reverse t) = getDual (foldMap (Dual . f) t)
-    {-# INLINE foldMap #-}
-    foldr f z (Reverse t) = foldl (flip f) z t
-    {-# INLINE foldr #-}
-    foldl f z (Reverse t) = foldr (flip f) z t
-    {-# INLINE foldl #-}
-    foldr1 f (Reverse t) = foldl1 (flip f) t
-    {-# INLINE foldr1 #-}
-    foldl1 f (Reverse t) = foldr1 (flip f) t
-    {-# INLINE foldl1 #-}
-#if MIN_VERSION_base(4,8,0)
-    null (Reverse t) = null t
-    length (Reverse t) = length t
-#endif
-
--- | Traverse from right to left.
-instance (Traversable f) => Traversable (Reverse f) where
-    traverse f (Reverse t) =
-        fmap Reverse . forwards $ traverse (Backwards . f) t
-    {-# INLINE traverse #-}
-
-#if MIN_VERSION_base(4,12,0)
--- | Derived instance.
-instance Contravariant f => Contravariant (Reverse f) where
-    contramap f = Reverse . contramap f . getReverse
-    {-# INLINE contramap #-}
-#endif
diff --git a/third_party/bazel/rules_haskell/examples/transformers/LICENSE b/third_party/bazel/rules_haskell/examples/transformers/LICENSE
deleted file mode 100644
index 92337b951eb0..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/LICENSE
+++ /dev/null
@@ -1,31 +0,0 @@
-The Glasgow Haskell Compiler License
-
-Copyright 2004, The University Court of the University of Glasgow.
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-- Redistributions of source code must retain the above copyright notice,
-this list of conditions and the following disclaimer.
-
-- Redistributions in binary form must reproduce the above copyright notice,
-this list of conditions and the following disclaimer in the documentation
-and/or other materials provided with the distribution.
-
-- Neither name of the University nor the names of its contributors may be
-used to endorse or promote products derived from this software without
-specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY COURT OF THE UNIVERSITY OF
-GLASGOW AND THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
-INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
-FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
-UNIVERSITY COURT OF THE UNIVERSITY OF GLASGOW OR THE CONTRIBUTORS BE LIABLE
-FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
-DAMAGE.
diff --git a/third_party/bazel/rules_haskell/examples/transformers/Setup.hs b/third_party/bazel/rules_haskell/examples/transformers/Setup.hs
deleted file mode 100644
index 9a994af677b0..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/Setup.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-import Distribution.Simple
-main = defaultMain
diff --git a/third_party/bazel/rules_haskell/examples/transformers/changelog b/third_party/bazel/rules_haskell/examples/transformers/changelog
deleted file mode 100644
index 5dd688f35b78..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/changelog
+++ /dev/null
@@ -1,124 +0,0 @@
--*-change-log-*-
-
-0.5.6.2 Ross Paterson <R.Paterson@city.ac.uk> Feb 2019
-	* Further backward compatability fix
-
-0.5.6.1 Ross Paterson <R.Paterson@city.ac.uk> Feb 2019
-	* Backward compatability fix for MonadFix ListT instance
-
-0.5.6.0 Ross Paterson <R.Paterson@city.ac.uk> Feb 2019
-	* Generalized type of except
-	* Added Control.Monad.Trans.Writer.CPS and Control.Monad.Trans.RWS.CPS
-	* Added Contravariant instances
-	* Added MonadFix instance for ListT
-
-0.5.5.0 Ross Paterson <R.Paterson@city.ac.uk> Oct 2017
-	* Added mapSelect and mapSelectT
-	* Renamed selectToCont to selectToContT for consistency
-	* Defined explicit method definitions to fix space leaks
-	* Added missing Semigroup instance to `Constant` functor
-
-0.5.4.0 Ross Paterson <R.Paterson@city.ac.uk> Feb 2017
-	* Migrate Bifoldable and Bitraversable instances for Constant
-
-0.5.3.1 Ross Paterson <R.Paterson@city.ac.uk> Feb 2017
-	* Fixed for pre-AMP environments
-
-0.5.3.0 Ross Paterson <R.Paterson@city.ac.uk> Feb 2017
-	* Added AccumT and SelectT monad transformers
-	* Deprecated ListT
-	* Added Monad (and related) instances for Reverse
-	* Added elimLift and eitherToErrors
-	* Added specialized definitions of several methods for efficiency
-	* Removed specialized definition of sequenceA for Reverse
-	* Backported Eq1/Ord1/Read1/Show1 instances for Proxy
-
-0.5.2.0 Ross Paterson <R.Paterson@city.ac.uk> Feb 2016
-	* Re-added orphan instances for Either to deprecated module
-	* Added lots of INLINE pragmas
-
-0.5.1.0 Ross Paterson <R.Paterson@city.ac.uk> Jan 2016
-	* Bump minor version number, required by added instances
-
-0.5.0.2 Ross Paterson <R.Paterson@city.ac.uk> Jan 2016
-	* Backported extra instances for Identity
-
-0.5.0.1 Ross Paterson <R.Paterson@city.ac.uk> Jan 2016
-	* Tightened GHC bounds for PolyKinds and DeriveDataTypeable
-
-0.5.0.0 Ross Paterson <R.Paterson@city.ac.uk> Dec 2015
-	* Control.Monad.IO.Class in base for GHC >= 8.0
-	* Data.Functor.{Classes,Compose,Product,Sum} in base for GHC >= 8.0
-	* Added PolyKinds for GHC >= 7.4
-	* Added instances of base classes MonadZip and MonadFail
-	* Changed liftings of Prelude classes to use explicit dictionaries
-
-0.4.3.0 Ross Paterson <R.Paterson@city.ac.uk> Mar 2015
-	* Added Eq1, Ord1, Show1 and Read1 instances for Const
-
-0.4.2.0 Ross Paterson <ross@soi.city.ac.uk> Nov 2014
-	* Dropped compatibility with base-1.x
-	* Data.Functor.Identity in base for GHC >= 7.10
-	* Added mapLift and runErrors to Control.Applicative.Lift
-	* Added AutoDeriveTypeable for GHC >= 7.10
-	* Expanded messages from mfix on ExceptT and MaybeT
-
-0.4.1.0 Ross Paterson <ross@soi.city.ac.uk> May 2014
-	* Reverted to record syntax for newtypes until next major release
-
-0.4.0.0 Ross Paterson <ross@soi.city.ac.uk> May 2014
-	* Added Sum type
-	* Added modify', a strict version of modify, to the state monads
-	* Added ExceptT and deprecated ErrorT
-	* Added infixr 9 `Compose` to match (.)
-	* Added Eq, Ord, Read and Show instances where possible
-	* Replaced record syntax for newtypes with separate inverse functions
-	* Added delimited continuation functions to ContT
-	* Added instance Alternative IO to ErrorT
-	* Handled disappearance of Control.Monad.Instances
-
-0.3.0.0 Ross Paterson <ross@soi.city.ac.uk> Mar 2012
-	* Added type synonyms for signatures of complex operations
-	* Generalized state, reader and writer constructor functions
-	* Added Lift, Backwards/Reverse
-	* Added MonadFix instances for IdentityT and MaybeT
-	* Added Foldable and Traversable instances
-	* Added Monad instances for Product
-
-0.2.2.1 Ross Paterson <ross@soi.city.ac.uk> Oct 2013
-	* Backport of fix for disappearance of Control.Monad.Instances
-
-0.2.2.0 Ross Paterson <ross@soi.city.ac.uk> Sep 2010
-	* Handled move of Either instances to base package
-
-0.2.1.0 Ross Paterson <ross@soi.city.ac.uk> Apr 2010
-	* Added Alternative instance for Compose
-	* Added Data.Functor.Product
-
-0.2.0.0 Ross Paterson <ross@soi.city.ac.uk> Mar 2010
-	* Added Constant and Compose
-	* Renamed modules to avoid clash with mtl
-	* Removed Monad constraint from Monad instance for ContT
-
-0.1.4.0 Ross Paterson <ross@soi.city.ac.uk> Mar 2009
-	* Adjusted lifting of Identity and Maybe transformers
-
-0.1.3.0 Ross Paterson <ross@soi.city.ac.uk> Mar 2009
-	* Added IdentityT transformer
-	* Added Applicative and Alternative instances for (Either e)
-
-0.1.1.0 Ross Paterson <ross@soi.city.ac.uk> Jan 2009
-	* Made all Functor instances assume Functor
-
-0.1.0.1 Ross Paterson <ross@soi.city.ac.uk> Jan 2009
-	* Adjusted dependencies
-
-0.1.0.0 Ross Paterson <ross@soi.city.ac.uk> Jan 2009
-	* Two versions of lifting of callcc through StateT
-	* Added Applicative instances
-
-0.0.1.0 Ross Paterson <ross@soi.city.ac.uk> Jan 2009
-	* Added constructors state, etc for simple monads
-
-0.0.0.0 Ross Paterson <ross@soi.city.ac.uk> Jan 2009
-	* Split Haskell 98 transformers from the mtl
diff --git a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre709/Data/Functor/Identity.hs b/third_party/bazel/rules_haskell/examples/transformers/legacy/pre709/Data/Functor/Identity.hs
deleted file mode 100644
index 940e4e470f47..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre709/Data/Functor/Identity.hs
+++ /dev/null
@@ -1,259 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 700
-{-# LANGUAGE DeriveDataTypeable #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE Trustworthy #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 708
-{-# LANGUAGE AutoDeriveTypeable #-}
-{-# LANGUAGE DataKinds #-}
-#endif
-#if MIN_VERSION_base(4,7,0)
--- We need to implement bitSize for the Bits instance, but it's deprecated.
-{-# OPTIONS_GHC -fno-warn-deprecations #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Data.Functor.Identity
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  ross@soi.city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- The identity functor and monad.
---
--- This trivial type constructor serves two purposes:
---
--- * It can be used with functions parameterized by functor or monad classes.
---
--- * It can be used as a base monad to which a series of monad
---   transformers may be applied to construct a composite monad.
---   Most monad transformer modules include the special case of
---   applying the transformer to 'Identity'.  For example, @State s@
---   is an abbreviation for @StateT s 'Identity'@.
------------------------------------------------------------------------------
-
-module Data.Functor.Identity (
-    Identity(..),
-  ) where
-
-import Data.Bits
-import Control.Applicative
-import Control.Arrow (Arrow((***)))
-import Control.Monad.Fix
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith, munzip))
-#endif
-import Data.Foldable (Foldable(foldMap))
-import Data.Monoid (Monoid(mempty, mappend))
-import Data.String (IsString(fromString))
-import Data.Traversable (Traversable(traverse))
-#if __GLASGOW_HASKELL__ >= 700
-import Data.Data
-#endif
-import Data.Ix (Ix(..))
-import Foreign (Storable(..), castPtr)
-#if __GLASGOW_HASKELL__ >= 702
-import GHC.Generics
-#endif
-
--- | Identity functor and monad. (a non-strict monad)
-newtype Identity a = Identity { runIdentity :: a }
-    deriving ( Eq, Ord
-#if __GLASGOW_HASKELL__ >= 700
-             , Data, Typeable
-#endif
-#if __GLASGOW_HASKELL__ >= 702
-             , Generic
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-             , Generic1
-#endif
-             )
-
-instance (Bits a) => Bits (Identity a) where
-    Identity x .&. Identity y     = Identity (x .&. y)
-    Identity x .|. Identity y     = Identity (x .|. y)
-    xor (Identity x) (Identity y) = Identity (xor x y)
-    complement   (Identity x)     = Identity (complement x)
-    shift        (Identity x) i   = Identity (shift    x i)
-    rotate       (Identity x) i   = Identity (rotate   x i)
-    setBit       (Identity x) i   = Identity (setBit   x i)
-    clearBit     (Identity x) i   = Identity (clearBit x i)
-    shiftL       (Identity x) i   = Identity (shiftL   x i)
-    shiftR       (Identity x) i   = Identity (shiftR   x i)
-    rotateL      (Identity x) i   = Identity (rotateL  x i)
-    rotateR      (Identity x) i   = Identity (rotateR  x i)
-    testBit      (Identity x) i   = testBit x i
-    bitSize      (Identity x)     = bitSize x
-    isSigned     (Identity x)     = isSigned x
-    bit i                         = Identity (bit i)
-#if MIN_VERSION_base(4,5,0)
-    unsafeShiftL (Identity x) i   = Identity (unsafeShiftL x i)
-    unsafeShiftR (Identity x) i   = Identity (unsafeShiftR x i)
-    popCount     (Identity x)     = popCount x
-#endif
-#if MIN_VERSION_base(4,7,0)
-    zeroBits                      = Identity zeroBits
-    bitSizeMaybe (Identity x)     = bitSizeMaybe x
-#endif
-
-instance (Bounded a) => Bounded (Identity a) where
-    minBound = Identity minBound
-    maxBound = Identity maxBound
-
-instance (Enum a) => Enum (Identity a) where
-    succ (Identity x)     = Identity (succ x)
-    pred (Identity x)     = Identity (pred x)
-    toEnum i              = Identity (toEnum i)
-    fromEnum (Identity x) = fromEnum x
-    enumFrom (Identity x) = map Identity (enumFrom x)
-    enumFromThen (Identity x) (Identity y) = map Identity (enumFromThen x y)
-    enumFromTo   (Identity x) (Identity y) = map Identity (enumFromTo   x y)
-    enumFromThenTo (Identity x) (Identity y) (Identity z) =
-        map Identity (enumFromThenTo x y z)
-
-#if MIN_VERSION_base(4,7,0)
-instance (FiniteBits a) => FiniteBits (Identity a) where
-    finiteBitSize (Identity x) = finiteBitSize x
-#endif
-
-instance (Floating a) => Floating (Identity a) where
-    pi                                = Identity pi
-    exp   (Identity x)                = Identity (exp x)
-    log   (Identity x)                = Identity (log x)
-    sqrt  (Identity x)                = Identity (sqrt x)
-    sin   (Identity x)                = Identity (sin x)
-    cos   (Identity x)                = Identity (cos x)
-    tan   (Identity x)                = Identity (tan x)
-    asin  (Identity x)                = Identity (asin x)
-    acos  (Identity x)                = Identity (acos x)
-    atan  (Identity x)                = Identity (atan x)
-    sinh  (Identity x)                = Identity (sinh x)
-    cosh  (Identity x)                = Identity (cosh x)
-    tanh  (Identity x)                = Identity (tanh x)
-    asinh (Identity x)                = Identity (asinh x)
-    acosh (Identity x)                = Identity (acosh x)
-    atanh (Identity x)                = Identity (atanh x)
-    Identity x ** Identity y          = Identity (x ** y)
-    logBase (Identity x) (Identity y) = Identity (logBase x y)
-
-instance (Fractional a) => Fractional (Identity a) where
-    Identity x / Identity y = Identity (x / y)
-    recip (Identity x)      = Identity (recip x)
-    fromRational r          = Identity (fromRational r)
-
-instance (IsString a) => IsString (Identity a) where
-    fromString s = Identity (fromString s)
-
-instance (Ix a) => Ix (Identity a) where
-    range     (Identity x, Identity y) = map Identity (range (x, y))
-    index     (Identity x, Identity y) (Identity i) = index     (x, y) i
-    inRange   (Identity x, Identity y) (Identity e) = inRange   (x, y) e
-    rangeSize (Identity x, Identity y) = rangeSize (x, y)
-
-instance (Integral a) => Integral (Identity a) where
-    quot    (Identity x) (Identity y) = Identity (quot x y)
-    rem     (Identity x) (Identity y) = Identity (rem  x y)
-    div     (Identity x) (Identity y) = Identity (div  x y)
-    mod     (Identity x) (Identity y) = Identity (mod  x y)
-    quotRem (Identity x) (Identity y) = (Identity *** Identity) (quotRem x y)
-    divMod  (Identity x) (Identity y) = (Identity *** Identity) (divMod  x y)
-    toInteger (Identity x)            = toInteger x
-
-instance (Monoid a) => Monoid (Identity a) where
-    mempty = Identity mempty
-    mappend (Identity x) (Identity y) = Identity (mappend x y)
-
-instance (Num a) => Num (Identity a) where
-    Identity x + Identity y = Identity (x + y)
-    Identity x - Identity y = Identity (x - y)
-    Identity x * Identity y = Identity (x * y)
-    negate (Identity x)     = Identity (negate x)
-    abs    (Identity x)     = Identity (abs    x)
-    signum (Identity x)     = Identity (signum x)
-    fromInteger n           = Identity (fromInteger n)
-
-instance (Real a) => Real (Identity a) where
-    toRational (Identity x) = toRational x
-
-instance (RealFloat a) => RealFloat (Identity a) where
-    floatRadix     (Identity x)     = floatRadix     x
-    floatDigits    (Identity x)     = floatDigits    x
-    floatRange     (Identity x)     = floatRange     x
-    decodeFloat    (Identity x)     = decodeFloat    x
-    exponent       (Identity x)     = exponent       x
-    isNaN          (Identity x)     = isNaN          x
-    isInfinite     (Identity x)     = isInfinite     x
-    isDenormalized (Identity x)     = isDenormalized x
-    isNegativeZero (Identity x)     = isNegativeZero x
-    isIEEE         (Identity x)     = isIEEE         x
-    significand    (Identity x)     = significand (Identity x)
-    scaleFloat s   (Identity x)     = Identity (scaleFloat s x)
-    encodeFloat m n                 = Identity (encodeFloat m n)
-    atan2 (Identity x) (Identity y) = Identity (atan2 x y)
-
-instance (RealFrac a) => RealFrac (Identity a) where
-    properFraction (Identity x) = (id *** Identity) (properFraction x)
-    truncate       (Identity x) = truncate x
-    round          (Identity x) = round    x
-    ceiling        (Identity x) = ceiling  x
-    floor          (Identity x) = floor    x
-
-instance (Storable a) => Storable (Identity a) where
-    sizeOf    (Identity x)       = sizeOf x
-    alignment (Identity x)       = alignment x
-    peekElemOff p i              = fmap Identity (peekElemOff (castPtr p) i)
-    pokeElemOff p i (Identity x) = pokeElemOff (castPtr p) i x
-    peekByteOff p i              = fmap Identity (peekByteOff p i)
-    pokeByteOff p i (Identity x) = pokeByteOff p i x
-    peek p                       = fmap runIdentity (peek (castPtr p))
-    poke p (Identity x)          = poke (castPtr p) x
-
--- These instances would be equivalent to the derived instances of the
--- newtype if the field were removed.
-
-instance (Read a) => Read (Identity a) where
-    readsPrec d = readParen (d > 10) $ \ r ->
-        [(Identity x,t) | ("Identity",s) <- lex r, (x,t) <- readsPrec 11 s]
-
-instance (Show a) => Show (Identity a) where
-    showsPrec d (Identity x) = showParen (d > 10) $
-        showString "Identity " . showsPrec 11 x
-
--- ---------------------------------------------------------------------------
--- Identity instances for Functor and Monad
-
-instance Functor Identity where
-    fmap f m = Identity (f (runIdentity m))
-
-instance Foldable Identity where
-    foldMap f (Identity x) = f x
-
-instance Traversable Identity where
-    traverse f (Identity x) = Identity <$> f x
-
-instance Applicative Identity where
-    pure a = Identity a
-    Identity f <*> Identity x = Identity (f x)
-
-instance Monad Identity where
-    return a = Identity a
-    m >>= k  = k (runIdentity m)
-
-instance MonadFix Identity where
-    mfix f = Identity (fix (runIdentity . f))
-
-#if MIN_VERSION_base(4,4,0)
-instance MonadZip Identity where
-    mzipWith f (Identity x) (Identity y) = Identity (f x y)
-    munzip (Identity (a, b)) = (Identity a, Identity b)
-#endif
diff --git a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Control/Monad/IO/Class.hs b/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Control/Monad/IO/Class.hs
deleted file mode 100644
index 7c74d4ef0d71..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Control/Monad/IO/Class.hs
+++ /dev/null
@@ -1,51 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 708
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE StandaloneDeriving #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.IO.Class
--- Copyright   :  (c) Andy Gill 2001,
---                (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Class of monads based on @IO@.
------------------------------------------------------------------------------
-
-module Control.Monad.IO.Class (
-    MonadIO(..)
-  ) where
-
-#if __GLASGOW_HASKELL__ >= 708
-import Data.Typeable
-#endif
-
--- | Monads in which 'IO' computations may be embedded.
--- Any monad built by applying a sequence of monad transformers to the
--- 'IO' monad will be an instance of this class.
---
--- Instances should satisfy the following laws, which state that 'liftIO'
--- is a transformer of monads:
---
--- * @'liftIO' . 'return' = 'return'@
---
--- * @'liftIO' (m >>= f) = 'liftIO' m >>= ('liftIO' . f)@
-
-class (Monad m) => MonadIO m where
-    -- | Lift a computation from the 'IO' monad.
-    liftIO :: IO a -> m a
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable MonadIO
-#endif
-
-instance MonadIO IO where
-    liftIO = id
diff --git a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Classes.hs b/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Classes.hs
deleted file mode 100644
index bda1749643d1..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Classes.hs
+++ /dev/null
@@ -1,529 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Safe #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 708
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE StandaloneDeriving #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Data.Functor.Classes
--- Copyright   :  (c) Ross Paterson 2013
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Liftings of the Prelude classes 'Eq', 'Ord', 'Read' and 'Show' to
--- unary and binary type constructors.
---
--- These classes are needed to express the constraints on arguments of
--- transformers in portable Haskell.  Thus for a new transformer @T@,
--- one might write instances like
---
--- > instance (Eq1 f) => Eq1 (T f) where ...
--- > instance (Ord1 f) => Ord1 (T f) where ...
--- > instance (Read1 f) => Read1 (T f) where ...
--- > instance (Show1 f) => Show1 (T f) where ...
---
--- If these instances can be defined, defining instances of the base
--- classes is mechanical:
---
--- > instance (Eq1 f, Eq a) => Eq (T f a) where (==) = eq1
--- > instance (Ord1 f, Ord a) => Ord (T f a) where compare = compare1
--- > instance (Read1 f, Read a) => Read (T f a) where readsPrec = readsPrec1
--- > instance (Show1 f, Show a) => Show (T f a) where showsPrec = showsPrec1
---
------------------------------------------------------------------------------
-
-module Data.Functor.Classes (
-    -- * Liftings of Prelude classes
-    -- ** For unary constructors
-    Eq1(..), eq1,
-    Ord1(..), compare1,
-    Read1(..), readsPrec1,
-    Show1(..), showsPrec1,
-    -- ** For binary constructors
-    Eq2(..), eq2,
-    Ord2(..), compare2,
-    Read2(..), readsPrec2,
-    Show2(..), showsPrec2,
-    -- * Helper functions
-    -- $example
-    readsData,
-    readsUnaryWith,
-    readsBinaryWith,
-    showsUnaryWith,
-    showsBinaryWith,
-    -- ** Obsolete helpers
-    readsUnary,
-    readsUnary1,
-    readsBinary1,
-    showsUnary,
-    showsUnary1,
-    showsBinary1,
-  ) where
-
-import Control.Applicative (Const(Const))
-import Data.Functor.Identity (Identity(Identity))
-import Data.Monoid (mappend)
-#if MIN_VERSION_base(4,7,0)
-import Data.Proxy (Proxy(Proxy))
-#endif
-#if __GLASGOW_HASKELL__ >= 708
-import Data.Typeable
-#endif
-import Text.Show (showListWith)
-
--- | Lifting of the 'Eq' class to unary type constructors.
-class Eq1 f where
-    -- | Lift an equality test through the type constructor.
-    --
-    -- The function will usually be applied to an equality function,
-    -- but the more general type ensures that the implementation uses
-    -- it to compare elements of the first container with elements of
-    -- the second.
-    liftEq :: (a -> b -> Bool) -> f a -> f b -> Bool
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Eq1
-#endif
-
--- | Lift the standard @('==')@ function through the type constructor.
-eq1 :: (Eq1 f, Eq a) => f a -> f a -> Bool
-eq1 = liftEq (==)
-
--- | Lifting of the 'Ord' class to unary type constructors.
-class (Eq1 f) => Ord1 f where
-    -- | Lift a 'compare' function through the type constructor.
-    --
-    -- The function will usually be applied to a comparison function,
-    -- but the more general type ensures that the implementation uses
-    -- it to compare elements of the first container with elements of
-    -- the second.
-    liftCompare :: (a -> b -> Ordering) -> f a -> f b -> Ordering
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Ord1
-#endif
-
--- | Lift the standard 'compare' function through the type constructor.
-compare1 :: (Ord1 f, Ord a) => f a -> f a -> Ordering
-compare1 = liftCompare compare
-
--- | Lifting of the 'Read' class to unary type constructors.
-class Read1 f where
-    -- | 'readsPrec' function for an application of the type constructor
-    -- based on 'readsPrec' and 'readList' functions for the argument type.
-    liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (f a)
-
-    -- | 'readList' function for an application of the type constructor
-    -- based on 'readsPrec' and 'readList' functions for the argument type.
-    -- The default implementation using standard list syntax is correct
-    -- for most types.
-    liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [f a]
-    liftReadList rp rl = readListWith (liftReadsPrec rp rl 0)
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Read1
-#endif
-
--- | Read a list (using square brackets and commas), given a function
--- for reading elements.
-readListWith :: ReadS a -> ReadS [a]
-readListWith rp =
-    readParen False (\r -> [pr | ("[",s) <- lex r, pr <- readl s])
-  where
-    readl s = [([],t) | ("]",t) <- lex s] ++
-        [(x:xs,u) | (x,t) <- rp s, (xs,u) <- readl' t]
-    readl' s = [([],t) | ("]",t) <- lex s] ++
-        [(x:xs,v) | (",",t) <- lex s, (x,u) <- rp t, (xs,v) <- readl' u]
-
--- | Lift the standard 'readsPrec' and 'readList' functions through the
--- type constructor.
-readsPrec1 :: (Read1 f, Read a) => Int -> ReadS (f a)
-readsPrec1 = liftReadsPrec readsPrec readList
-
--- | Lifting of the 'Show' class to unary type constructors.
-class Show1 f where
-    -- | 'showsPrec' function for an application of the type constructor
-    -- based on 'showsPrec' and 'showList' functions for the argument type.
-    liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) ->
-        Int -> f a -> ShowS
-
-    -- | 'showList' function for an application of the type constructor
-    -- based on 'showsPrec' and 'showList' functions for the argument type.
-    -- The default implementation using standard list syntax is correct
-    -- for most types.
-    liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) ->
-        [f a] -> ShowS
-    liftShowList sp sl = showListWith (liftShowsPrec sp sl 0)
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Show1
-#endif
-
--- | Lift the standard 'showsPrec' and 'showList' functions through the
--- type constructor.
-showsPrec1 :: (Show1 f, Show a) => Int -> f a -> ShowS
-showsPrec1 = liftShowsPrec showsPrec showList
-
--- | Lifting of the 'Eq' class to binary type constructors.
-class Eq2 f where
-    -- | Lift equality tests through the type constructor.
-    --
-    -- The function will usually be applied to equality functions,
-    -- but the more general type ensures that the implementation uses
-    -- them to compare elements of the first container with elements of
-    -- the second.
-    liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> f a c -> f b d -> Bool
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Eq2
-#endif
-
--- | Lift the standard @('==')@ function through the type constructor.
-eq2 :: (Eq2 f, Eq a, Eq b) => f a b -> f a b -> Bool
-eq2 = liftEq2 (==) (==)
-
--- | Lifting of the 'Ord' class to binary type constructors.
-class (Eq2 f) => Ord2 f where
-    -- | Lift 'compare' functions through the type constructor.
-    --
-    -- The function will usually be applied to comparison functions,
-    -- but the more general type ensures that the implementation uses
-    -- them to compare elements of the first container with elements of
-    -- the second.
-    liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) ->
-        f a c -> f b d -> Ordering
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Ord2
-#endif
-
--- | Lift the standard 'compare' function through the type constructor.
-compare2 :: (Ord2 f, Ord a, Ord b) => f a b -> f a b -> Ordering
-compare2 = liftCompare2 compare compare
-
--- | Lifting of the 'Read' class to binary type constructors.
-class Read2 f where
-    -- | 'readsPrec' function for an application of the type constructor
-    -- based on 'readsPrec' and 'readList' functions for the argument types.
-    liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] ->
-        (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (f a b)
-
-    -- | 'readList' function for an application of the type constructor
-    -- based on 'readsPrec' and 'readList' functions for the argument types.
-    -- The default implementation using standard list syntax is correct
-    -- for most types.
-    liftReadList2 :: (Int -> ReadS a) -> ReadS [a] ->
-        (Int -> ReadS b) -> ReadS [b] -> ReadS [f a b]
-    liftReadList2 rp1 rl1 rp2 rl2 =
-        readListWith (liftReadsPrec2 rp1 rl1 rp2 rl2 0)
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Read2
-#endif
-
--- | Lift the standard 'readsPrec' function through the type constructor.
-readsPrec2 :: (Read2 f, Read a, Read b) => Int -> ReadS (f a b)
-readsPrec2 = liftReadsPrec2 readsPrec readList readsPrec readList
-
--- | Lifting of the 'Show' class to binary type constructors.
-class Show2 f where
-    -- | 'showsPrec' function for an application of the type constructor
-    -- based on 'showsPrec' and 'showList' functions for the argument types.
-    liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) ->
-        (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> f a b -> ShowS
-
-    -- | 'showList' function for an application of the type constructor
-    -- based on 'showsPrec' and 'showList' functions for the argument types.
-    -- The default implementation using standard list syntax is correct
-    -- for most types.
-    liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) ->
-        (Int -> b -> ShowS) -> ([b] -> ShowS) -> [f a b] -> ShowS
-    liftShowList2 sp1 sl1 sp2 sl2 =
-        showListWith (liftShowsPrec2 sp1 sl1 sp2 sl2 0)
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Show2
-#endif
-
--- | Lift the standard 'showsPrec' function through the type constructor.
-showsPrec2 :: (Show2 f, Show a, Show b) => Int -> f a b -> ShowS
-showsPrec2 = liftShowsPrec2 showsPrec showList showsPrec showList
-
--- Instances for Prelude type constructors
-
-instance Eq1 Maybe where
-    liftEq _ Nothing Nothing = True
-    liftEq _ Nothing (Just _) = False
-    liftEq _ (Just _) Nothing = False
-    liftEq eq (Just x) (Just y) = eq x y
-
-instance Ord1 Maybe where
-    liftCompare _ Nothing Nothing = EQ
-    liftCompare _ Nothing (Just _) = LT
-    liftCompare _ (Just _) Nothing = GT
-    liftCompare comp (Just x) (Just y) = comp x y
-
-instance Read1 Maybe where
-    liftReadsPrec rp _ d =
-         readParen False (\ r -> [(Nothing,s) | ("Nothing",s) <- lex r])
-         `mappend`
-         readsData (readsUnaryWith rp "Just" Just) d
-
-instance Show1 Maybe where
-    liftShowsPrec _ _ _ Nothing = showString "Nothing"
-    liftShowsPrec sp _ d (Just x) = showsUnaryWith sp "Just" d x
-
-instance Eq1 [] where
-    liftEq _ [] [] = True
-    liftEq _ [] (_:_) = False
-    liftEq _ (_:_) [] = False
-    liftEq eq (x:xs) (y:ys) = eq x y && liftEq eq xs ys
-
-instance Ord1 [] where
-    liftCompare _ [] [] = EQ
-    liftCompare _ [] (_:_) = LT
-    liftCompare _ (_:_) [] = GT
-    liftCompare comp (x:xs) (y:ys) = comp x y `mappend` liftCompare comp xs ys
-
-instance Read1 [] where
-    liftReadsPrec _ rl _ = rl
-
-instance Show1 [] where
-    liftShowsPrec _ sl _ = sl
-
-instance Eq2 (,) where
-    liftEq2 e1 e2 (x1, y1) (x2, y2) = e1 x1 x2 && e2 y1 y2
-
-instance Ord2 (,) where
-    liftCompare2 comp1 comp2 (x1, y1) (x2, y2) =
-        comp1 x1 x2 `mappend` comp2 y1 y2
-
-instance Read2 (,) where
-    liftReadsPrec2 rp1 _ rp2 _ _ = readParen False $ \ r ->
-        [((x,y), w) | ("(",s) <- lex r,
-                      (x,t)   <- rp1 0 s,
-                      (",",u) <- lex t,
-                      (y,v)   <- rp2 0 u,
-                      (")",w) <- lex v]
-
-instance Show2 (,) where
-    liftShowsPrec2 sp1 _ sp2 _ _ (x, y) =
-        showChar '(' . sp1 0 x . showChar ',' . sp2 0 y . showChar ')'
-
-instance (Eq a) => Eq1 ((,) a) where
-    liftEq = liftEq2 (==)
-
-instance (Ord a) => Ord1 ((,) a) where
-    liftCompare = liftCompare2 compare
-
-instance (Read a) => Read1 ((,) a) where
-    liftReadsPrec = liftReadsPrec2 readsPrec readList
-
-instance (Show a) => Show1 ((,) a) where
-    liftShowsPrec = liftShowsPrec2 showsPrec showList
-
-instance Eq2 Either where
-    liftEq2 e1 _ (Left x) (Left y) = e1 x y
-    liftEq2 _ _ (Left _) (Right _) = False
-    liftEq2 _ _ (Right _) (Left _) = False
-    liftEq2 _ e2 (Right x) (Right y) = e2 x y
-
-instance Ord2 Either where
-    liftCompare2 comp1 _ (Left x) (Left y) = comp1 x y
-    liftCompare2 _ _ (Left _) (Right _) = LT
-    liftCompare2 _ _ (Right _) (Left _) = GT
-    liftCompare2 _ comp2 (Right x) (Right y) = comp2 x y
-
-instance Read2 Either where
-    liftReadsPrec2 rp1 _ rp2 _ = readsData $
-         readsUnaryWith rp1 "Left" Left `mappend`
-         readsUnaryWith rp2 "Right" Right
-
-instance Show2 Either where
-    liftShowsPrec2 sp1 _ _ _ d (Left x) = showsUnaryWith sp1 "Left" d x
-    liftShowsPrec2 _ _ sp2 _ d (Right x) = showsUnaryWith sp2 "Right" d x
-
-instance (Eq a) => Eq1 (Either a) where
-    liftEq = liftEq2 (==)
-
-instance (Ord a) => Ord1 (Either a) where
-    liftCompare = liftCompare2 compare
-
-instance (Read a) => Read1 (Either a) where
-    liftReadsPrec = liftReadsPrec2 readsPrec readList
-
-instance (Show a) => Show1 (Either a) where
-    liftShowsPrec = liftShowsPrec2 showsPrec showList
-
-#if MIN_VERSION_base(4,7,0)
-instance Eq1 Proxy where
-    liftEq _ _ _ = True
-
-instance Ord1 Proxy where
-    liftCompare _ _ _ = EQ
-
-instance Show1 Proxy where
-    liftShowsPrec _ _ _ _ = showString "Proxy"
-
-instance Read1 Proxy where
-    liftReadsPrec _ _ d =
-        readParen (d > 10) (\r -> [(Proxy, s) | ("Proxy",s) <- lex r ])
-#endif
-
--- Instances for other functors defined in the base package
-
-instance Eq1 Identity where
-    liftEq eq (Identity x) (Identity y) = eq x y
-
-instance Ord1 Identity where
-    liftCompare comp (Identity x) (Identity y) = comp x y
-
-instance Read1 Identity where
-    liftReadsPrec rp _ = readsData $
-         readsUnaryWith rp "Identity" Identity
-
-instance Show1 Identity where
-    liftShowsPrec sp _ d (Identity x) = showsUnaryWith sp "Identity" d x
-
-instance Eq2 Const where
-    liftEq2 eq _ (Const x) (Const y) = eq x y
-
-instance Ord2 Const where
-    liftCompare2 comp _ (Const x) (Const y) = comp x y
-
-instance Read2 Const where
-    liftReadsPrec2 rp _ _ _ = readsData $
-         readsUnaryWith rp "Const" Const
-
-instance Show2 Const where
-    liftShowsPrec2 sp _ _ _ d (Const x) = showsUnaryWith sp "Const" d x
-
-instance (Eq a) => Eq1 (Const a) where
-    liftEq = liftEq2 (==)
-instance (Ord a) => Ord1 (Const a) where
-    liftCompare = liftCompare2 compare
-instance (Read a) => Read1 (Const a) where
-    liftReadsPrec = liftReadsPrec2 readsPrec readList
-instance (Show a) => Show1 (Const a) where
-    liftShowsPrec = liftShowsPrec2 showsPrec showList
-
--- Building blocks
-
--- | @'readsData' p d@ is a parser for datatypes where each alternative
--- begins with a data constructor.  It parses the constructor and
--- passes it to @p@.  Parsers for various constructors can be constructed
--- with 'readsUnary', 'readsUnary1' and 'readsBinary1', and combined with
--- @mappend@ from the @Monoid@ class.
-readsData :: (String -> ReadS a) -> Int -> ReadS a
-readsData reader d =
-    readParen (d > 10) $ \ r -> [res | (kw,s) <- lex r, res <- reader kw s]
-
--- | @'readsUnaryWith' rp n c n'@ matches the name of a unary data constructor
--- and then parses its argument using @rp@.
-readsUnaryWith :: (Int -> ReadS a) -> String -> (a -> t) -> String -> ReadS t
-readsUnaryWith rp name cons kw s =
-    [(cons x,t) | kw == name, (x,t) <- rp 11 s]
-
--- | @'readsBinaryWith' rp1 rp2 n c n'@ matches the name of a binary
--- data constructor and then parses its arguments using @rp1@ and @rp2@
--- respectively.
-readsBinaryWith :: (Int -> ReadS a) -> (Int -> ReadS b) ->
-    String -> (a -> b -> t) -> String -> ReadS t
-readsBinaryWith rp1 rp2 name cons kw s =
-    [(cons x y,u) | kw == name, (x,t) <- rp1 11 s, (y,u) <- rp2 11 t]
-
--- | @'showsUnaryWith' sp n d x@ produces the string representation of a
--- unary data constructor with name @n@ and argument @x@, in precedence
--- context @d@.
-showsUnaryWith :: (Int -> a -> ShowS) -> String -> Int -> a -> ShowS
-showsUnaryWith sp name d x = showParen (d > 10) $
-    showString name . showChar ' ' . sp 11 x
-
--- | @'showsBinaryWith' sp1 sp2 n d x y@ produces the string
--- representation of a binary data constructor with name @n@ and arguments
--- @x@ and @y@, in precedence context @d@.
-showsBinaryWith :: (Int -> a -> ShowS) -> (Int -> b -> ShowS) ->
-    String -> Int -> a -> b -> ShowS
-showsBinaryWith sp1 sp2 name d x y = showParen (d > 10) $
-    showString name . showChar ' ' . sp1 11 x . showChar ' ' . sp2 11 y
-
--- Obsolete building blocks
-
--- | @'readsUnary' n c n'@ matches the name of a unary data constructor
--- and then parses its argument using 'readsPrec'.
-{-# DEPRECATED readsUnary "Use readsUnaryWith to define liftReadsPrec" #-}
-readsUnary :: (Read a) => String -> (a -> t) -> String -> ReadS t
-readsUnary name cons kw s =
-    [(cons x,t) | kw == name, (x,t) <- readsPrec 11 s]
-
--- | @'readsUnary1' n c n'@ matches the name of a unary data constructor
--- and then parses its argument using 'readsPrec1'.
-{-# DEPRECATED readsUnary1 "Use readsUnaryWith to define liftReadsPrec" #-}
-readsUnary1 :: (Read1 f, Read a) => String -> (f a -> t) -> String -> ReadS t
-readsUnary1 name cons kw s =
-    [(cons x,t) | kw == name, (x,t) <- readsPrec1 11 s]
-
--- | @'readsBinary1' n c n'@ matches the name of a binary data constructor
--- and then parses its arguments using 'readsPrec1'.
-{-# DEPRECATED readsBinary1 "Use readsBinaryWith to define liftReadsPrec" #-}
-readsBinary1 :: (Read1 f, Read1 g, Read a) =>
-    String -> (f a -> g a -> t) -> String -> ReadS t
-readsBinary1 name cons kw s =
-    [(cons x y,u) | kw == name,
-        (x,t) <- readsPrec1 11 s, (y,u) <- readsPrec1 11 t]
-
--- | @'showsUnary' n d x@ produces the string representation of a unary data
--- constructor with name @n@ and argument @x@, in precedence context @d@.
-{-# DEPRECATED showsUnary "Use showsUnaryWith to define liftShowsPrec" #-}
-showsUnary :: (Show a) => String -> Int -> a -> ShowS
-showsUnary name d x = showParen (d > 10) $
-    showString name . showChar ' ' . showsPrec 11 x
-
--- | @'showsUnary1' n d x@ produces the string representation of a unary data
--- constructor with name @n@ and argument @x@, in precedence context @d@.
-{-# DEPRECATED showsUnary1 "Use showsUnaryWith to define liftShowsPrec" #-}
-showsUnary1 :: (Show1 f, Show a) => String -> Int -> f a -> ShowS
-showsUnary1 name d x = showParen (d > 10) $
-    showString name . showChar ' ' . showsPrec1 11 x
-
--- | @'showsBinary1' n d x y@ produces the string representation of a binary
--- data constructor with name @n@ and arguments @x@ and @y@, in precedence
--- context @d@.
-{-# DEPRECATED showsBinary1 "Use showsBinaryWith to define liftShowsPrec" #-}
-showsBinary1 :: (Show1 f, Show1 g, Show a) =>
-    String -> Int -> f a -> g a -> ShowS
-showsBinary1 name d x y = showParen (d > 10) $
-    showString name . showChar ' ' . showsPrec1 11 x .
-        showChar ' ' . showsPrec1 11 y
-
-{- $example
-These functions can be used to assemble 'Read' and 'Show' instances for
-new algebraic types.  For example, given the definition
-
-> data T f a = Zero a | One (f a) | Two a (f a)
-
-a standard 'Read1' instance may be defined as
-
-> instance (Read1 f) => Read1 (T f) where
->     liftReadsPrec rp rl = readsData $
->         readsUnaryWith rp "Zero" Zero `mappend`
->         readsUnaryWith (liftReadsPrec rp rl) "One" One `mappend`
->         readsBinaryWith rp (liftReadsPrec rp rl) "Two" Two
-
-and the corresponding 'Show1' instance as
-
-> instance (Show1 f) => Show1 (T f) where
->     liftShowsPrec sp _ d (Zero x) =
->         showsUnaryWith sp "Zero" d x
->     liftShowsPrec sp sl d (One x) =
->         showsUnaryWith (liftShowsPrec sp sl) "One" d x
->     liftShowsPrec sp sl d (Two x y) =
->         showsBinaryWith sp (liftShowsPrec sp sl) "Two" d x y
-
--}
diff --git a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Compose.hs b/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Compose.hs
deleted file mode 100644
index ed781309aff8..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Compose.hs
+++ /dev/null
@@ -1,154 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE EmptyDataDecls #-}
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE Trustworthy #-}
-{-# LANGUAGE TypeFamilies #-}
-{-# LANGUAGE TypeOperators #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 708
-{-# LANGUAGE AutoDeriveTypeable #-}
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE KindSignatures #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Data.Functor.Compose
--- Copyright   :  (c) Ross Paterson 2010
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Composition of functors.
------------------------------------------------------------------------------
-
-module Data.Functor.Compose (
-    Compose(..),
-  ) where
-
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-
-import Control.Applicative
-#if __GLASGOW_HASKELL__ >= 708
-import Data.Data
-#endif
-import Data.Foldable (Foldable(foldMap))
-import Data.Traversable (Traversable(traverse))
-#if __GLASGOW_HASKELL__ >= 702
-import GHC.Generics
-#endif
-
-infixr 9 `Compose`
-
--- | Right-to-left composition of functors.
--- The composition of applicative functors is always applicative,
--- but the composition of monads is not always a monad.
-newtype Compose f g a = Compose { getCompose :: f (g a) }
-
-#if __GLASGOW_HASKELL__ >= 702
-deriving instance Generic (Compose f g a)
-
-instance Functor f => Generic1 (Compose f g) where
-    type Rep1 (Compose f g) =
-      D1 MDCompose
-        (C1 MCCompose
-          (S1 MSCompose (f :.: Rec1 g)))
-    from1 (Compose x) = M1 (M1 (M1 (Comp1 (fmap Rec1 x))))
-    to1 (M1 (M1 (M1 x))) = Compose (fmap unRec1 (unComp1 x))
-
-data MDCompose
-data MCCompose
-data MSCompose
-
-instance Datatype MDCompose where
-    datatypeName _ = "Compose"
-    moduleName   _ = "Data.Functor.Compose"
-# if __GLASGOW_HASKELL__ >= 708
-    isNewtype    _ = True
-# endif
-
-instance Constructor MCCompose where
-    conName     _ = "Compose"
-    conIsRecord _ = True
-
-instance Selector MSCompose where
-    selName _ = "getCompose"
-#endif
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Compose
-deriving instance (Data (f (g a)), Typeable f, Typeable g, Typeable a)
-               => Data (Compose (f :: * -> *) (g :: * -> *) (a :: *))
-#endif
-
--- Instances of lifted Prelude classes
-
-instance (Eq1 f, Eq1 g) => Eq1 (Compose f g) where
-    liftEq eq (Compose x) (Compose y) = liftEq (liftEq eq) x y
-
-instance (Ord1 f, Ord1 g) => Ord1 (Compose f g) where
-    liftCompare comp (Compose x) (Compose y) =
-        liftCompare (liftCompare comp) x y
-
-instance (Read1 f, Read1 g) => Read1 (Compose f g) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp' rl') "Compose" Compose
-      where
-        rp' = liftReadsPrec rp rl
-        rl' = liftReadList rp rl
-
-instance (Show1 f, Show1 g) => Show1 (Compose f g) where
-    liftShowsPrec sp sl d (Compose x) =
-        showsUnaryWith (liftShowsPrec sp' sl') "Compose" d x
-      where
-        sp' = liftShowsPrec sp sl
-        sl' = liftShowList sp sl
-
--- Instances of Prelude classes
-
-instance (Eq1 f, Eq1 g, Eq a) => Eq (Compose f g a) where
-    (==) = eq1
-
-instance (Ord1 f, Ord1 g, Ord a) => Ord (Compose f g a) where
-    compare = compare1
-
-instance (Read1 f, Read1 g, Read a) => Read (Compose f g a) where
-    readsPrec = readsPrec1
-
-instance (Show1 f, Show1 g, Show a) => Show (Compose f g a) where
-    showsPrec = showsPrec1
-
--- Functor instances
-
-instance (Functor f, Functor g) => Functor (Compose f g) where
-    fmap f (Compose x) = Compose (fmap (fmap f) x)
-
-instance (Foldable f, Foldable g) => Foldable (Compose f g) where
-    foldMap f (Compose t) = foldMap (foldMap f) t
-
-instance (Traversable f, Traversable g) => Traversable (Compose f g) where
-    traverse f (Compose t) = Compose <$> traverse (traverse f) t
-
-instance (Applicative f, Applicative g) => Applicative (Compose f g) where
-    pure x = Compose (pure (pure x))
-    Compose f <*> Compose x = Compose ((<*>) <$> f <*> x)
-
-instance (Alternative f, Applicative g) => Alternative (Compose f g) where
-    empty = Compose empty
-    Compose x <|> Compose y = Compose (x <|> y)
-
-#if MIN_VERSION_base(4,12,0)
-instance (Functor f, Contravariant g) => Contravariant (Compose f g) where
-    contramap f (Compose fga) = Compose (fmap (contramap f) fga)
-#endif
diff --git a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Product.hs b/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Product.hs
deleted file mode 100644
index ba0dc0407e00..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Product.hs
+++ /dev/null
@@ -1,156 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE EmptyDataDecls #-}
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE Trustworthy #-}
-{-# LANGUAGE TypeFamilies #-}
-{-# LANGUAGE TypeOperators #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 708
-{-# LANGUAGE AutoDeriveTypeable #-}
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE KindSignatures #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Data.Functor.Product
--- Copyright   :  (c) Ross Paterson 2010
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Products, lifted to functors.
------------------------------------------------------------------------------
-
-module Data.Functor.Product (
-    Product(..),
-  ) where
-
-import Control.Applicative
-import Control.Monad (MonadPlus(..))
-import Control.Monad.Fix (MonadFix(..))
-#if MIN_VERSION_base(4,4,0)
-import Control.Monad.Zip (MonadZip(mzipWith))
-#endif
-#if __GLASGOW_HASKELL__ >= 708
-import Data.Data
-#endif
-import Data.Foldable (Foldable(foldMap))
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Monoid (mappend)
-import Data.Traversable (Traversable(traverse))
-#if __GLASGOW_HASKELL__ >= 702
-import GHC.Generics
-#endif
-
--- | Lifted product of functors.
-data Product f g a = Pair (f a) (g a)
-
-#if __GLASGOW_HASKELL__ >= 702
-deriving instance Generic (Product f g a)
-
-instance Generic1 (Product f g) where
-    type Rep1 (Product f g) =
-      D1 MDProduct
-        (C1 MCPair
-          (S1 NoSelector (Rec1 f) :*: S1 NoSelector (Rec1 g)))
-    from1 (Pair f g) = M1 (M1 (M1 (Rec1 f) :*: M1 (Rec1 g)))
-    to1 (M1 (M1 (M1 f :*: M1 g))) = Pair (unRec1 f) (unRec1 g)
-
-data MDProduct
-data MCPair
-
-instance Datatype MDProduct where
-    datatypeName _ = "Product"
-    moduleName   _ = "Data.Functor.Product"
-
-instance Constructor MCPair where
-    conName _ = "Pair"
-#endif
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Product
-deriving instance (Data (f a), Data (g a), Typeable f, Typeable g, Typeable a)
-               => Data (Product (f :: * -> *) (g :: * -> *) (a :: *))
-#endif
-
-instance (Eq1 f, Eq1 g) => Eq1 (Product f g) where
-    liftEq eq (Pair x1 y1) (Pair x2 y2) = liftEq eq x1 x2 && liftEq eq y1 y2
-
-instance (Ord1 f, Ord1 g) => Ord1 (Product f g) where
-    liftCompare comp (Pair x1 y1) (Pair x2 y2) =
-        liftCompare comp x1 x2 `mappend` liftCompare comp y1 y2
-
-instance (Read1 f, Read1 g) => Read1 (Product f g) where
-    liftReadsPrec rp rl = readsData $
-        readsBinaryWith (liftReadsPrec rp rl) (liftReadsPrec rp rl) "Pair" Pair
-
-instance (Show1 f, Show1 g) => Show1 (Product f g) where
-    liftShowsPrec sp sl d (Pair x y) =
-        showsBinaryWith (liftShowsPrec sp sl) (liftShowsPrec sp sl) "Pair" d x y
-
-instance (Eq1 f, Eq1 g, Eq a) => Eq (Product f g a)
-    where (==) = eq1
-instance (Ord1 f, Ord1 g, Ord a) => Ord (Product f g a) where
-    compare = compare1
-instance (Read1 f, Read1 g, Read a) => Read (Product f g a) where
-    readsPrec = readsPrec1
-instance (Show1 f, Show1 g, Show a) => Show (Product f g a) where
-    showsPrec = showsPrec1
-
-instance (Functor f, Functor g) => Functor (Product f g) where
-    fmap f (Pair x y) = Pair (fmap f x) (fmap f y)
-
-instance (Foldable f, Foldable g) => Foldable (Product f g) where
-    foldMap f (Pair x y) = foldMap f x `mappend` foldMap f y
-
-instance (Traversable f, Traversable g) => Traversable (Product f g) where
-    traverse f (Pair x y) = Pair <$> traverse f x <*> traverse f y
-
-instance (Applicative f, Applicative g) => Applicative (Product f g) where
-    pure x = Pair (pure x) (pure x)
-    Pair f g <*> Pair x y = Pair (f <*> x) (g <*> y)
-
-instance (Alternative f, Alternative g) => Alternative (Product f g) where
-    empty = Pair empty empty
-    Pair x1 y1 <|> Pair x2 y2 = Pair (x1 <|> x2) (y1 <|> y2)
-
-instance (Monad f, Monad g) => Monad (Product f g) where
-#if !(MIN_VERSION_base(4,8,0))
-    return x = Pair (return x) (return x)
-#endif
-    Pair m n >>= f = Pair (m >>= fstP . f) (n >>= sndP . f)
-      where
-        fstP (Pair a _) = a
-        sndP (Pair _ b) = b
-
-instance (MonadPlus f, MonadPlus g) => MonadPlus (Product f g) where
-    mzero = Pair mzero mzero
-    Pair x1 y1 `mplus` Pair x2 y2 = Pair (x1 `mplus` x2) (y1 `mplus` y2)
-
-instance (MonadFix f, MonadFix g) => MonadFix (Product f g) where
-    mfix f = Pair (mfix (fstP . f)) (mfix (sndP . f))
-      where
-        fstP (Pair a _) = a
-        sndP (Pair _ b) = b
-
-#if MIN_VERSION_base(4,4,0)
-instance (MonadZip f, MonadZip g) => MonadZip (Product f g) where
-    mzipWith f (Pair x1 y1) (Pair x2 y2) = Pair (mzipWith f x1 x2) (mzipWith f y1 y2)
-#endif
-
-#if MIN_VERSION_base(4,12,0)
-instance (Contravariant f, Contravariant g) => Contravariant (Product f g) where
-    contramap f (Pair a b) = Pair (contramap f a) (contramap f b)
-#endif
diff --git a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Sum.hs b/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Sum.hs
deleted file mode 100644
index e6d1428b30e3..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/legacy/pre711/Data/Functor/Sum.hs
+++ /dev/null
@@ -1,136 +0,0 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE EmptyDataDecls #-}
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE Trustworthy #-}
-{-# LANGUAGE TypeFamilies #-}
-{-# LANGUAGE TypeOperators #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
-{-# LANGUAGE PolyKinds #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 708
-{-# LANGUAGE AutoDeriveTypeable #-}
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE KindSignatures #-}
-#endif
------------------------------------------------------------------------------
--- |
--- Module      :  Data.Functor.Sum
--- Copyright   :  (c) Ross Paterson 2014
--- License     :  BSD-style (see the file LICENSE)
---
--- Maintainer  :  R.Paterson@city.ac.uk
--- Stability   :  experimental
--- Portability :  portable
---
--- Sums, lifted to functors.
------------------------------------------------------------------------------
-
-module Data.Functor.Sum (
-    Sum(..),
-  ) where
-
-import Control.Applicative
-#if __GLASGOW_HASKELL__ >= 708
-import Data.Data
-#endif
-import Data.Foldable (Foldable(foldMap))
-import Data.Functor.Classes
-#if MIN_VERSION_base(4,12,0)
-import Data.Functor.Contravariant
-#endif
-import Data.Monoid (mappend)
-import Data.Traversable (Traversable(traverse))
-#if __GLASGOW_HASKELL__ >= 702
-import GHC.Generics
-#endif
-
--- | Lifted sum of functors.
-data Sum f g a = InL (f a) | InR (g a)
-
-#if __GLASGOW_HASKELL__ >= 702
-deriving instance Generic (Sum f g a)
-
-instance Generic1 (Sum f g) where
-    type Rep1 (Sum f g) =
-      D1 MDSum (C1 MCInL (S1 NoSelector (Rec1 f))
-            :+: C1 MCInR (S1 NoSelector (Rec1 g)))
-    from1 (InL f) = M1 (L1 (M1 (M1 (Rec1 f))))
-    from1 (InR g) = M1 (R1 (M1 (M1 (Rec1 g))))
-    to1 (M1 (L1 (M1 (M1 f)))) = InL (unRec1 f)
-    to1 (M1 (R1 (M1 (M1 g)))) = InR (unRec1 g)
-
-data MDSum
-data MCInL
-data MCInR
-
-instance Datatype MDSum where
-    datatypeName _ = "Sum"
-    moduleName   _ = "Data.Functor.Sum"
-
-instance Constructor MCInL where
-    conName _ = "InL"
-
-instance Constructor MCInR where
-    conName _ = "InR"
-#endif
-
-#if __GLASGOW_HASKELL__ >= 708
-deriving instance Typeable Sum
-deriving instance (Data (f a), Data (g a), Typeable f, Typeable g, Typeable a)
-               => Data (Sum (f :: * -> *) (g :: * -> *) (a :: *))
-#endif
-
-instance (Eq1 f, Eq1 g) => Eq1 (Sum f g) where
-    liftEq eq (InL x1) (InL x2) = liftEq eq x1 x2
-    liftEq _ (InL _) (InR _) = False
-    liftEq _ (InR _) (InL _) = False
-    liftEq eq (InR y1) (InR y2) = liftEq eq y1 y2
-
-instance (Ord1 f, Ord1 g) => Ord1 (Sum f g) where
-    liftCompare comp (InL x1) (InL x2) = liftCompare comp x1 x2
-    liftCompare _ (InL _) (InR _) = LT
-    liftCompare _ (InR _) (InL _) = GT
-    liftCompare comp (InR y1) (InR y2) = liftCompare comp y1 y2
-
-instance (Read1 f, Read1 g) => Read1 (Sum f g) where
-    liftReadsPrec rp rl = readsData $
-        readsUnaryWith (liftReadsPrec rp rl) "InL" InL `mappend`
-        readsUnaryWith (liftReadsPrec rp rl) "InR" InR
-
-instance (Show1 f, Show1 g) => Show1 (Sum f g) where
-    liftShowsPrec sp sl d (InL x) =
-        showsUnaryWith (liftShowsPrec sp sl) "InL" d x
-    liftShowsPrec sp sl d (InR y) =
-        showsUnaryWith (liftShowsPrec sp sl) "InR" d y
-
-instance (Eq1 f, Eq1 g, Eq a) => Eq (Sum f g a) where
-    (==) = eq1
-instance (Ord1 f, Ord1 g, Ord a) => Ord (Sum f g a) where
-    compare = compare1
-instance (Read1 f, Read1 g, Read a) => Read (Sum f g a) where
-    readsPrec = readsPrec1
-instance (Show1 f, Show1 g, Show a) => Show (Sum f g a) where
-    showsPrec = showsPrec1
-
-instance (Functor f, Functor g) => Functor (Sum f g) where
-    fmap f (InL x) = InL (fmap f x)
-    fmap f (InR y) = InR (fmap f y)
-
-instance (Foldable f, Foldable g) => Foldable (Sum f g) where
-    foldMap f (InL x) = foldMap f x
-    foldMap f (InR y) = foldMap f y
-
-instance (Traversable f, Traversable g) => Traversable (Sum f g) where
-    traverse f (InL x) = InL <$> traverse f x
-    traverse f (InR y) = InR <$> traverse f y
-
-#if MIN_VERSION_base(4,12,0)
-instance (Contravariant f, Contravariant g) => Contravariant (Sum f g) where
-    contramap f (InL xs) = InL (contramap f xs)
-    contramap f (InR ys) = InR (contramap f ys)
-#endif
diff --git a/third_party/bazel/rules_haskell/examples/transformers/transformers.cabal b/third_party/bazel/rules_haskell/examples/transformers/transformers.cabal
deleted file mode 100644
index 945adda910fd..000000000000
--- a/third_party/bazel/rules_haskell/examples/transformers/transformers.cabal
+++ /dev/null
@@ -1,91 +0,0 @@
-name:         transformers
-version:      0.5.6.2
-license:      BSD3
-license-file: LICENSE
-author:       Andy Gill, Ross Paterson
-maintainer:   Ross Paterson <R.Paterson@city.ac.uk>
-bug-reports:  http://hub.darcs.net/ross/transformers/issues
-category:     Control
-synopsis:     Concrete functor and monad transformers
-description:
-    A portable library of functor and monad transformers, inspired by
-    the paper
-    .
-    * \"Functional Programming with Overloading and Higher-Order
-    Polymorphism\", by Mark P Jones,
-    in /Advanced School of Functional Programming/, 1995
-    (<http://web.cecs.pdx.edu/~mpj/pubs/springschool.html>).
-    .
-    This package contains:
-    .
-    * the monad transformer class (in "Control.Monad.Trans.Class")
-    .
-    * concrete functor and monad transformers, each with associated
-      operations and functions to lift operations associated with other
-      transformers.
-    .
-    The package can be used on its own in portable Haskell code, in
-    which case operations need to be manually lifted through transformer
-    stacks (see "Control.Monad.Trans.Class" for some examples).
-    Alternatively, it can be used with the non-portable monad classes in
-    the @mtl@ or @monads-tf@ packages, which automatically lift operations
-    introduced by monad transformers through other transformers.
-build-type: Simple
-extra-source-files:
-    changelog
-cabal-version: >= 1.6
-
-source-repository head
-  type: darcs
-  location: http://hub.darcs.net/ross/transformers
-
-library
-  build-depends: base >= 2 && < 6
-  hs-source-dirs: .
-  if !impl(ghc>=7.9)
-    -- Data.Functor.Identity was moved into base-4.8.0.0 (GHC 7.10)
-    -- see also https://ghc.haskell.org/trac/ghc/ticket/9664
-    -- NB: using impl(ghc>=7.9) instead of fragile Cabal flags
-    hs-source-dirs: legacy/pre709
-    exposed-modules: Data.Functor.Identity
-  if !impl(ghc>=7.11)
-    -- modules moved into base-4.9.0 (GHC 8.0)
-    -- see https://ghc.haskell.org/trac/ghc/ticket/10773
-    -- see https://ghc.haskell.org/trac/ghc/ticket/11135
-    hs-source-dirs: legacy/pre711
-    exposed-modules:
-      Control.Monad.IO.Class
-      Data.Functor.Classes
-      Data.Functor.Compose
-      Data.Functor.Product
-      Data.Functor.Sum
-  if impl(ghc>=7.2 && <7.5)
-    -- Prior to GHC 7.5, GHC.Generics lived in ghc-prim
-    build-depends: ghc-prim
-  exposed-modules:
-    Control.Applicative.Backwards
-    Control.Applicative.Lift
-    Control.Monad.Signatures
-    Control.Monad.Trans.Accum
-    Control.Monad.Trans.Class
-    Control.Monad.Trans.Cont
-    Control.Monad.Trans.Except
-    Control.Monad.Trans.Error
-    Control.Monad.Trans.Identity
-    Control.Monad.Trans.List
-    Control.Monad.Trans.Maybe
-    Control.Monad.Trans.Reader
-    Control.Monad.Trans.RWS
-    Control.Monad.Trans.RWS.CPS
-    Control.Monad.Trans.RWS.Lazy
-    Control.Monad.Trans.RWS.Strict
-    Control.Monad.Trans.Select
-    Control.Monad.Trans.State
-    Control.Monad.Trans.State.Lazy
-    Control.Monad.Trans.State.Strict
-    Control.Monad.Trans.Writer
-    Control.Monad.Trans.Writer.CPS
-    Control.Monad.Trans.Writer.Lazy
-    Control.Monad.Trans.Writer.Strict
-    Data.Functor.Constant
-    Data.Functor.Reverse