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lens 2.2 → 2.3

raw patch · 9 files changed

+256/−83 lines, 9 files

Files

.vim.custom view
@@ -16,7 +16,6 @@ set list  map <F2> :exec ":!hasktags -x -c --ignore src"<CR><CR>-" autocmd! bufwritepost *.hs :exec ":!hasktags -x -c --ignore src"  au BufWritePre *.hs,*.markdown silent! cal StripTrailingWhitespace() au BufWritePost *.hs silent! :exec ":!hasktags -x -c --ignore src"
CHANGELOG.markdown view
@@ -1,3 +1,10 @@+2.3+---+* Added missing `{-# INLINE #-}` pragmas+* Renamed `meanwhile` to `throughout` in `Control.Parallel.Strategies.Lens`+* Added `Magnify` to `Control.Lens.Getter`.+* Added `Zoom` to `Control.Lens.Type`.+ 2.2 --- * Added `<&=`, `<&~`, `<|=`, and `<|~`
lens.cabal view
@@ -1,6 +1,6 @@ name:          lens category:      Data, Lenses-version:       2.2+version:       2.3 license:       BSD3 cabal-version: >= 1.8 license-file:  LICENSE@@ -33,12 +33,12 @@   .   The core of this hierarchy looks like:   .-  <<https://github.com/ekmett/lens/wiki/images/Hierarchy-2.2.png>>+  <<https://github.com/ekmett/lens/wiki/images/Hierarchy-2.3.png>>   .   You can compose any two elements of the hierarchy above using (.) from the Prelude, and you can   use any element of the hierarchy as any type it links to above it.   .-  The result is their lowest upper bound in the hierarchy (or an error f that bound doesn't exist).+  The result is their lowest upper bound in the hierarchy (or an error if that bound doesn't exist).   .   For instance:   .
src/Control/Lens.hs view
@@ -41,7 +41,7 @@ -- -- <http://github.com/ekmett/lens/wiki> ----- <<http://github.com/ekmett/lens/wiki/images/Hierarchy-1.8.png>>+-- <<http://github.com/ekmett/lens/wiki/images/Hierarchy-2.3.png>> ---------------------------------------------------------------------------- module Control.Lens   ( module Control.Lens.Type
src/Control/Lens/Getter.hs view
@@ -1,4 +1,8 @@ {-# LANGUAGE Rank2Types #-}+{-# LANGUAGE MultiParamTypeClasses #-}+{-# LANGUAGE FunctionalDependencies #-}+{-# LANGUAGE UndecidableInstances #-}+{-# LANGUAGE FlexibleInstances #-} ------------------------------------------------------------------------------- -- | -- Module      :  Control.Lens.Getter@@ -51,6 +55,7 @@   , uses   , query   , queries+  , Magnify(..)   ) where  import Control.Applicative@@ -58,6 +63,18 @@ import Control.Lens.Internal import Control.Monad.Reader.Class       as Reader import Control.Monad.State.Class        as State+import Control.Monad.Trans.State.Lazy   as Lazy+import Control.Monad.Trans.State.Strict as Strict+import Control.Monad.Trans.Writer.Lazy   as Lazy+import Control.Monad.Trans.Writer.Strict as Strict+import Control.Monad.Trans.RWS.Lazy   as Lazy+import Control.Monad.Trans.RWS.Strict as Strict+import Control.Monad.Trans.Reader+import Control.Monad.Trans.Error+import Control.Monad.Trans.List+import Control.Monad.Trans.Identity+import Control.Monad.Trans.Cont+import Control.Monad.Trans.Maybe import Data.Functor.Compose import Data.Monoid @@ -256,6 +273,44 @@ {-# INLINE (^.) #-}  -------------------------------------------------------------------------------+-- MonadState+-------------------------------------------------------------------------------++-- |+-- Use the target of a 'Control.Lens.Type.Lens', 'Control.Lens.Iso.Iso', or+-- 'Getter' in the current state, or use a summary of a+-- 'Control.Lens.Fold.Fold' or 'Control.Lens.Traversal.Traversal' that points+-- to a monoidal value.+--+-- @+-- use :: 'MonadState' a m             => 'Getter' a c             -> m c+-- use :: ('MonadState' a m, 'Monoid' r) => 'Control.Lens.Fold.Fold' a r               -> m r+-- use :: 'MonadState' a m             => 'Control.Lens.Type.Simple' 'Control.Lens.Iso.Iso' a c         -> m c+-- use :: 'MonadState' a m             => 'Control.Lens.Type.Simple' 'Control.Lens.Type.Lens' a c        -> m c+-- use :: ('MonadState' a m, 'Monoid' r) => 'Control.Lens.Type.Simple' 'Control.Lens.Traversal.Traversal' a r   -> m r+-- @+use :: MonadState a m => Getting c a c -> m c+use l = State.gets (view l)+{-# INLINE use #-}++-- |+-- Use the target of a 'Control.Lens.Type.Lens', 'Control.Lens.Iso.Iso' or+-- 'Getter' in the current state, or use a summary of a+-- 'Control.Lens.Fold.Fold' or 'Control.Lens.Traversal.Traversal' that+-- points to a monoidal value.+--+-- @+-- uses :: 'MonadState' a m             => 'Getter' a c           -> (c -> e) -> m e+-- uses :: ('MonadState' a m, 'Monoid' r) => 'Control.Lens.Fold.Fold' a c             -> (c -> r) -> m r+-- uses :: 'MonadState' a m             => 'Control.Lens.Type.Simple' 'Control.Lens.Type.Lens' a c      -> (c -> e) -> m e+-- uses :: 'MonadState' a m             => 'Control.Lens.Type.Simple' 'Control.Lens.Iso.Iso' a c       -> (c -> e) -> m e+-- uses :: ('MonadState' a m, 'Monoid' r) => 'Control.Lens.Type.Simple' 'Control.Lens.Traversal.Traversal' a c -> (c -> r) -> m r+-- @+uses :: MonadState a m => Getting e a c -> (c -> e) -> m e+uses l f = State.gets (views l f)+{-# INLINE uses #-}++------------------------------------------------------------------------------- -- MonadReader ------------------------------------------------------------------------------- @@ -293,40 +348,79 @@ queries l f = Reader.asks (views l f) {-# INLINE queries #-} ----------------------------------------------------------------------------------- MonadState-------------------------------------------------------------------------------- --- |--- Use the target of a 'Control.Lens.Type.Lens', 'Control.Lens.Iso.Iso', or--- 'Getter' in the current state, or use a summary of a--- 'Control.Lens.Fold.Fold' or 'Control.Lens.Traversal.Traversal' that points--- to a monoidal value.+-- | This class allows us to use 'magnify' part of the environment, changing the environment supplied by+-- many different monad transformers. Unlike 'focus' this can change the environment of a deeply nested monad transformer. ----- @--- use :: 'MonadState' a m             => 'Getter' a c             -> m c--- use :: ('MonadState' a m, 'Monoid' r) => 'Control.Lens.Fold.Fold' a r               -> m r--- use :: 'MonadState' a m             => 'Control.Lens.Type.Simple' 'Control.Lens.Iso.Iso' a c         -> m c--- use :: 'MonadState' a m             => 'Control.Lens.Type.Simple' 'Control.Lens.Type.Lens' a c        -> m c--- use :: ('MonadState' a m, 'Monoid' r) => 'Control.Lens.Type.Simple' 'Control.Lens.Traversal.Traversal' a r   -> m r--- @-use :: MonadState a m => Getting c a c -> m c-use l = State.gets (view l)-{-# INLINE use #-}+-- Also, unlike 'focus', this can be used with any valid 'Getter', but cannot be used with a 'Traversal' or 'Fold'.+class (MonadReader b m, MonadReader a n) => Magnify m n b a | m -> b, n -> a, m a -> n, n b -> m where+  -- | Run a monadic action in a larger environment than it was defined in, using a 'Getter'.+  --+  -- This acts like 'Control.Monad.Reader.Class.local', but can in many cases change the type of the environment as well.+  --+  -- This is commonly used to lift actions in a simpler Reader monad into a monad with a larger environment type.+  --+  -- This can be used to edit pretty much any monad transformer stack with an environment in it:+  --+  -- @+  -- magnify :: 'Getter' a b -> (b -> c) -> a -> c+  -- magnify :: 'Getter' a b -> RWS a w s c -> RWST b w s c+  -- magnify :: 'Getter' a b -> ErrorT e (Reader b) c -> ErrorT e (Reader a) c+  -- magnify :: 'Getter' a b -> ListT (ReaderT b (StateT s)) c -> ListT (ReaderT a (StateT s)) c+  -- ...+  -- @+  magnify :: Getter a b -> m c -> n c --- |--- Use the target of a 'Control.Lens.Type.Lens', 'Control.Lens.Iso.Iso' or--- 'Getter' in the current state, or use a summary of a--- 'Control.Lens.Fold.Fold' or 'Control.Lens.Traversal.Traversal' that--- points to a monoidal value.------ @--- uses :: 'MonadState' a m             => 'Getter' a c           -> (c -> e) -> m e--- uses :: ('MonadState' a m, 'Monoid' r) => 'Control.Lens.Fold.Fold' a c             -> (c -> r) -> m r--- uses :: 'MonadState' a m             => 'Control.Lens.Type.Simple' 'Control.Lens.Type.Lens' a c      -> (c -> e) -> m e--- uses :: 'MonadState' a m             => 'Control.Lens.Type.Simple' 'Control.Lens.Iso.Iso' a c       -> (c -> e) -> m e--- uses :: ('MonadState' a m, 'Monoid' r) => 'Control.Lens.Type.Simple' 'Control.Lens.Traversal.Traversal' a c -> (c -> r) -> m r--- @-uses :: MonadState a m => Getting e a c -> (c -> e) -> m e-uses l f = State.gets (views l f)-{-# INLINE uses #-}+instance Monad m => Magnify (ReaderT b m) (ReaderT a m) b a where+  magnify l (ReaderT m) = ReaderT $ \e -> m (e^.l)+  {-# INLINE magnify #-}++instance Magnify ((->) b) ((->) a) b a where+  magnify l bc a = bc (view l a)+  {-# INLINE magnify #-}++instance (Monad m, Monoid w) => Magnify (Strict.RWST b w s m) (Strict.RWST a w s m) b a where+  magnify l (Strict.RWST m) = Strict.RWST $ \a w -> m (a^.l) w+  {-# INLINE magnify #-}++instance (Monad m, Monoid w) => Magnify (Lazy.RWST b w s m) (Lazy.RWST a w s m) b a where+  magnify l (Lazy.RWST m) = Lazy.RWST $ \a w -> m (a^.l) w+  {-# INLINE magnify #-}++instance Magnify m n b a => Magnify (Strict.StateT s m) (Strict.StateT s n) b a where+  magnify l (Strict.StateT m) = Strict.StateT $ magnify l . m+  {-# INLINE magnify #-}++instance Magnify m n b a => Magnify (Lazy.StateT s m) (Lazy.StateT s n) b a where+  magnify l (Lazy.StateT m) = Lazy.StateT $ magnify l . m+  {-# INLINE magnify #-}++instance (Monoid w, Magnify m n b a) => Magnify (Strict.WriterT w m) (Strict.WriterT w n) b a where+  magnify l (Strict.WriterT m) = Strict.WriterT (magnify l m)+  {-# INLINE magnify #-}++instance (Monoid w, Magnify m n b a) => Magnify (Lazy.WriterT w m) (Lazy.WriterT w n) b a where+  magnify l (Lazy.WriterT m) = Lazy.WriterT (magnify l m)+  {-# INLINE magnify #-}++instance Magnify m n b a => Magnify (ListT m) (ListT n) b a where+  magnify l (ListT m) = ListT (magnify l m)+  {-# INLINE magnify #-}++instance Magnify m n b a => Magnify (MaybeT m) (MaybeT n) b a where+  magnify l (MaybeT m) = MaybeT (magnify l m)+  {-# INLINE magnify #-}++instance Magnify m n b a => Magnify (IdentityT m) (IdentityT n) b a where+  magnify l (IdentityT m) = IdentityT (magnify l m)+  {-# INLINE magnify #-}++instance (Error e, Magnify m n b a) => Magnify (ErrorT e m) (ErrorT e n) b a where+  magnify l (ErrorT m) = ErrorT (magnify l m)+  {-# INLINE magnify #-}++instance Magnify m m a a => Magnify (ContT r m) (ContT r m) a a where+  magnify l (ContT m) = ContT $ \k -> do+    r <- Reader.ask+    magnify l (m (magnify (to (const r)) . k))+  {-# INLINE magnify #-}
src/Control/Lens/Type.hs view
@@ -4,6 +4,7 @@ {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE FunctionalDependencies #-} {-# LANGUAGE FlexibleInstances #-}+{-# LANGUAGE UndecidableInstances #-}  #ifndef MIN_VERSION_mtl #define MIN_VERSION_mtl(x,y,z) 1@@ -61,6 +62,7 @@    -- * Traversing and Lensing   , Focus(..)+  , Zoom(..)    -- * Common Lenses   -- ** Tuples@@ -109,8 +111,18 @@ import Control.Monad.State.Class        as State import Control.Monad.Trans.State.Lazy   as Lazy import Control.Monad.Trans.State.Strict as Strict+import Control.Monad.Trans.Writer.Lazy   as Lazy+import Control.Monad.Trans.Writer.Strict as Strict+import Control.Monad.Trans.RWS.Lazy   as Lazy+import Control.Monad.Trans.RWS.Strict as Strict import Control.Monad.Trans.Reader+import Control.Monad.Trans.Cont+import Control.Monad.Trans.Error+import Control.Monad.Trans.List+import Control.Monad.Trans.Identity+import Control.Monad.Trans.Maybe import Data.Functor.Identity+import Data.Monoid  infixr 4 %%~ infix  4 %%=@@ -274,6 +286,7 @@ #endif {-# INLINE (%%=) #-} + -- | This class allows us to use 'focus' on a number of different monad -- transformers. class Focus st where@@ -318,7 +331,7 @@   focus_ l m = Strict.StateT $     unfocusing . l (Focusing . Strict.runStateT (liftM skip m))   {-# INLINE focus_ #-}-  setFocus l m = Strict.state $+  setFocus l m = State.state $     (,) () . runIdentity . l (Identity . snd . Strict.runState m)  instance Focus Lazy.StateT where@@ -328,7 +341,7 @@   focus_ l m = Lazy.StateT $     unfocusing . l (Focusing . Lazy.runStateT (liftM skip m))   {-# INLINE focus_ #-}-  setFocus l m = Lazy.state $+  setFocus l m = State.state $     (,) () . runIdentity . l (Identity . snd . Lazy.runState m)   {-# INLINE setFocus #-} @@ -342,39 +355,90 @@   {-# INLINE focus_ #-}   setFocus _ _ = return () -- BOOORING +-- | This class allows us to use 'zoom' in, changing the State supplied by+-- many different monad transformers. Unlike 'focus' this can change the state+-- of a deeply nested monad transformer. However, also unlike 'focus' it can+-- only be used on an actual 'Lens' or 'Control.Lens.Iso.Iso' and cannot accept+-- a 'Control.Lens.Traversal.Traversal'+class (MonadState s m, MonadState t n) => Zoom m n s t | m -> s, n -> t, m t -> n, n s -> m where+  -- | Run a monadic action in a larger state than it was defined in,+  -- using a 'Simple' 'Lens'.+  --+  -- This is commonly used to lift actions in a simpler state monad into a+  -- state monad with a larger state type.+  --+  -- This can be used to edit pretty much any monad transformer stack with a state in it:+  --+  -- @+  -- zoom :: 'Monad' m => 'Simple' 'Lens' a b -> StateT b m c -> StateT a m c+  -- zoom :: 'Monad' m => 'Simple' 'Lens' a b -> RWST r w b m c -> RWST r w a m c+  -- zoom :: 'Monad' m => 'Simple' 'Lens' a b -> ErrorT e (RWST r w b m c) -> ErrorT e (RWST r w a m c)+  -- zoom :: 'Monad' m => 'Simple' 'Lens' a b -> ErrorT e (RWST r w b m c) -> ErrorT e (RWST r w a m c)+  -- ...+  -- @+  zoom :: SimpleLensLike (IndexedStore s s) t s -> m c -> n c++instance Monad m => Zoom (Strict.StateT s m) (Strict.StateT t m) s t where+  zoom = focus . clone+  {-# INLINE zoom #-}++instance Monad m => Zoom (Lazy.StateT s m) (Lazy.StateT t m) s t where+  zoom = focus . clone+  {-# INLINE zoom #-}++instance Zoom m n s t => Zoom (ReaderT e m) (ReaderT e n) s t where+  zoom l (ReaderT m) = ReaderT (zoom l . m)+  {-# INLINE zoom #-}++instance (Monoid w, Zoom m n s t) => Zoom (Strict.WriterT w m) (Strict.WriterT w n) s t where+  zoom l (Strict.WriterT m) = Strict.WriterT (zoom l m)+  {-# INLINE zoom #-}++instance (Monoid w, Zoom m n s t) => Zoom (Lazy.WriterT w m) (Lazy.WriterT w n) s t where+  zoom l (Lazy.WriterT m) = Lazy.WriterT (zoom l m)+  {-# INLINE zoom #-}++instance (Monoid w, Monad m) => Zoom (Strict.RWST r w s m) (Strict.RWST r w t m) s t where+  zoom l (Strict.RWST m) = Strict.RWST $ \ r t -> case l (IndexedStore id) t of+    IndexedStore st s -> do+      (a,s',w) <- m r s+      return (a,st s',w)+  {-# INLINE zoom #-}++instance (Monoid w, Monad m) => Zoom (Lazy.RWST r w s m) (Lazy.RWST r w t m) s t where+  zoom l (Lazy.RWST m) = Lazy.RWST $ \ r t -> case l (IndexedStore id) t of+    IndexedStore st s -> do+      (a,s',w) <- m r s+      return (a,st s',w)+  {-# INLINE zoom #-}++instance (Error e, Zoom m n s t) => Zoom (ErrorT e m) (ErrorT e n) s t where+  zoom l (ErrorT m) = ErrorT (zoom l m)+  {-# INLINE zoom #-}++instance Zoom m n s t => Zoom (ListT m) (ListT n) s t where+  zoom l (ListT m) = ListT (zoom l m)+  {-# INLINE zoom #-}++instance Zoom m n s t => Zoom (IdentityT m) (IdentityT n) s t where+  zoom l (IdentityT m) = IdentityT (zoom l m)+  {-# INLINE zoom #-}++instance Zoom m n s t => Zoom (MaybeT m) (MaybeT n) s t where+  zoom l (MaybeT m) = MaybeT (zoom l m)+  {-# INLINE zoom #-}++instance Zoom m m a a => Zoom (ContT r m) (ContT r m) a a where+  zoom l (ContT m) = ContT $ \k -> do+    f <- State.state $ \s -> case l (IndexedStore id) s of+      IndexedStore f t -> (f, t)+    r <- m k+    State.state $ \t -> (r, f t)+  {-# INLINE zoom #-}+ ------------------------------------------------------------------------------- -- Common Lenses ---------------------------------------------------------------------------------{---- | This is a lens that can change the value (and type) of the first field of--- a pair.------ >>> import Control.Lens--- >>> (1,2)^._1--- 1------ >>> _1 .~ "hello" $ (1,2)--- ("hello",2)------ @_1 :: 'Functor' f => (a -> f b) -> (a,c) -> f (a,c)@-_1 :: Lens (a,c) (b,c) a b-_1 f (a,c) = (\b -> (b,c)) <$> f a-{-# INLINE _1 #-}---- | As '_1', but for the second field of a pair.------ @--- 'Control.Lens.Fold.anyOf' '_2' :: (c -> 'Bool') -> (a, c) -> 'Bool'--- 'Data.Traversable.traverse' '.' '_2' :: ('Applicative' f, 'Data.Traversable.Traversable' t) => (a -> f b) -> t (c, a) -> f (t (c, b))--- 'Control.Lens.Fold.foldMapOf' ('Data.Traversable.traverse' '.' '_2') :: ('Data.Traversable.Traversable' t, 'Data.Monoid.Monoid' m) => (c -> m) -> t (b, c) -> m--- @------ @_2 :: 'Functor' f => (a -> f b) -> (c,a) -> f (c,b)@-_2 :: Lens (c,a) (c,b) a b-_2 f (c,a) = (,) c <$> f a-{-# INLINE _2 #-}--}  -- | This lens can be used to change the result of a function but only where -- the arguments match the key given.
src/Control/Parallel/Strategies/Lens.hs view
@@ -15,7 +15,7 @@   ( evalOf   , parOf   , after-  , meanwhile+  , throughout   ) where  import Control.Lens@@ -36,6 +36,7 @@ -- @ evalOf :: SimpleLensLike Eval a b -> Strategy b -> Strategy a evalOf l = l+{-# INLINE evalOf #-}  -- | Evaluate the targets of a 'Lens' or 'Traversal' according into a -- data structure according to a given 'Strategy' in parallel.@@ -49,6 +50,7 @@ -- @ parOf :: SimpleLensLike Eval a b -> Strategy b -> Strategy a parOf l s = l (rparWith s)+{-# INLINE parOf #-}  -- | Transform a 'Lens', 'Fold', 'Getter', 'Setter' or 'Traversal' to -- first evaluates its argument according to a given strategy /before/ proceeding.@@ -58,12 +60,14 @@ -- @ after :: Strategy a -> LensLike f a b c d -> LensLike f a b c d after s l f = l f $| s+{-# INLINE after #-}  -- | Transform a 'Lens', 'Fold', 'Getter', 'Setter' or 'Traversal' to -- evaluate its argument according to a given strategy /in parallel with/ evaluating. -- -- @--- 'meanwhile' 'rdeepseq' 'traverse' :: 'Traversable' t => 'Strategy' a -> 'Strategy' [a]+-- 'throughout' 'rdeepseq' 'traverse' :: 'Traversable' t => 'Strategy' a -> 'Strategy' [a] -- @-meanwhile :: Strategy a -> LensLike f a b c d -> LensLike f a b c d-meanwhile s l f = l f $|| s+throughout :: Strategy a -> LensLike f a b c d -> LensLike f a b c d+throughout s l f = l f $|| s+{-# INLINE throughout #-}
src/Control/Seq/Lens.hs view
@@ -22,3 +22,4 @@ -- @'seqFoldable' = 'seqOf' 'folded'@ seqOf :: Getting [c] a c -> Strategy c -> Strategy a seqOf l s = seqList s . toListOf l+{-# INLINE seqOf #-}
tests/properties.hs view
@@ -23,13 +23,13 @@ setter_composition l a (Fun _ f) (Fun _ g) = mapOf l f (mapOf l g a) == mapOf l (f . g) a  lens_set_view :: Eq a => Simple Lens a b -> a -> Bool-lens_set_view l a = set l (a^.l) a == a+lens_set_view l a = set l (view l a) a == a  lens_view_set :: Eq b => Simple Lens a b -> a -> b -> Bool-lens_view_set l a b = set l b a^.l == b+lens_view_set l a b = view l (set l b a) == b -traversal_set_set :: Eq a => Simple Traversal a b -> a -> b -> b -> Bool-traversal_set_set l a b c = set l c (set l b a) == set l c a+setter_set_set :: Eq a => Simple Setter a b -> a -> b -> b -> Bool+setter_set_set l a b c = set l c (set l b a) == set l c a  iso_hither :: Eq a => Simple Iso a b -> a -> Bool iso_hither l a = a ^.l.from l == a@@ -39,11 +39,11 @@  isSetter :: (Arbitrary a, Arbitrary b, CoArbitrary b, Show a, Show b, Eq a, Function b)          => Simple Setter a b -> Property-isSetter l = setter_id l .&. setter_composition l+isSetter l = setter_id l .&. setter_composition l .&. setter_set_set l  isTraversal :: (Arbitrary a, Arbitrary b, CoArbitrary b, Show a, Show b, Eq a, Function b)          => Simple Traversal a b -> Property-isTraversal l = isSetter l .&. traversal_set_set l+isTraversal l = isSetter l  isLens :: (Arbitrary a, Arbitrary b, CoArbitrary b, Show a, Show b, Eq a, Eq b, Function b)        => Simple Lens a b -> Property@@ -61,9 +61,13 @@ badIso = iso even fromEnum  -- Control.Lens.Type-prop_1                               = isLens (_1 :: Simple Lens (Int,Double) Int)+prop_1                               = isLens (_1 :: Simple Lens (Int,Double,()) Int) prop_2                               = isLens (_2 :: Simple Lens (Int,Bool) Bool)-prop_2_2                             = isLens (_2._2 :: Simple Lens (Int,(Int,Bool)) Bool)+prop_3                               = isLens (_3 :: Simple Lens (Int,Bool,()) ())+prop_4                               = isLens (_4 :: Simple Lens (Int,Bool,(),Maybe Int) (Maybe Int))+prop_5                               = isLens (_5 :: Simple Lens ((),(),(),(),Int) Int)++prop_2_2                             = isLens (_2._2 :: Simple Lens (Int,(Int,Bool),Double) Bool)  prop_illegal_lens                    = expectFailure $ isLens bad prop_illegal_traversal               = expectFailure $ isTraversal bad