{-# LANGUAGE UndecidableInstances #-}
{-# OPTIONS_GHC -Wno-orphans #-}
--------------------------------------------------------------------------------
-- |
-- Module      :  HGeometry.Sequence.NonEmpty
-- Copyright   :  (C) Frank Staals
-- License     :  see the LICENSE file
-- Maintainer  :  Frank Staals
--------------------------------------------------------------------------------
module HGeometry.Sequence.NonEmpty
  ( ViewL1(..)
  , ViewR1(..)
  , viewl1, viewr1
  , (|>>)
  , (<>>)
  -- , (<<>)
  , splitL1At
  , splitR1At
  ) where

import           Control.DeepSeq
import           Control.Lens
import qualified Data.Foldable as F
import           Data.Foldable1
import           Data.Foldable1.WithIndex
import           Data.Functor.Apply
import           Data.List.NonEmpty (NonEmpty(..))
import qualified Data.List.NonEmpty as NonEmpty
import           Data.Semigroup.Traversable
import           Data.Sequence (Seq(..))
import qualified Data.Sequence as Sequence
import           GHC.Exts (IsList(..))
import           GHC.Generics
import           HGeometry.Foldable.Util (HasFromFoldable1(..))

--------------------------------------------------------------------------------

-- | NonEmpty ViewL
data ViewL1 a = a :<< Seq a
  deriving stock (Int -> ViewL1 a -> ShowS
[ViewL1 a] -> ShowS
ViewL1 a -> String
(Int -> ViewL1 a -> ShowS)
-> (ViewL1 a -> String) -> ([ViewL1 a] -> ShowS) -> Show (ViewL1 a)
forall a. Show a => Int -> ViewL1 a -> ShowS
forall a. Show a => [ViewL1 a] -> ShowS
forall a. Show a => ViewL1 a -> String
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
$cshowsPrec :: forall a. Show a => Int -> ViewL1 a -> ShowS
showsPrec :: Int -> ViewL1 a -> ShowS
$cshow :: forall a. Show a => ViewL1 a -> String
show :: ViewL1 a -> String
$cshowList :: forall a. Show a => [ViewL1 a] -> ShowS
showList :: [ViewL1 a] -> ShowS
Show,ReadPrec [ViewL1 a]
ReadPrec (ViewL1 a)
Int -> ReadS (ViewL1 a)
ReadS [ViewL1 a]
(Int -> ReadS (ViewL1 a))
-> ReadS [ViewL1 a]
-> ReadPrec (ViewL1 a)
-> ReadPrec [ViewL1 a]
-> Read (ViewL1 a)
forall a. Read a => ReadPrec [ViewL1 a]
forall a. Read a => ReadPrec (ViewL1 a)
forall a. Read a => Int -> ReadS (ViewL1 a)
forall a. Read a => ReadS [ViewL1 a]
forall a.
(Int -> ReadS a)
-> ReadS [a] -> ReadPrec a -> ReadPrec [a] -> Read a
$creadsPrec :: forall a. Read a => Int -> ReadS (ViewL1 a)
readsPrec :: Int -> ReadS (ViewL1 a)
$creadList :: forall a. Read a => ReadS [ViewL1 a]
readList :: ReadS [ViewL1 a]
$creadPrec :: forall a. Read a => ReadPrec (ViewL1 a)
readPrec :: ReadPrec (ViewL1 a)
$creadListPrec :: forall a. Read a => ReadPrec [ViewL1 a]
readListPrec :: ReadPrec [ViewL1 a]
Read,ViewL1 a -> ViewL1 a -> Bool
(ViewL1 a -> ViewL1 a -> Bool)
-> (ViewL1 a -> ViewL1 a -> Bool) -> Eq (ViewL1 a)
forall a. Eq a => ViewL1 a -> ViewL1 a -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
$c== :: forall a. Eq a => ViewL1 a -> ViewL1 a -> Bool
== :: ViewL1 a -> ViewL1 a -> Bool
$c/= :: forall a. Eq a => ViewL1 a -> ViewL1 a -> Bool
/= :: ViewL1 a -> ViewL1 a -> Bool
Eq,Eq (ViewL1 a)
Eq (ViewL1 a) =>
(ViewL1 a -> ViewL1 a -> Ordering)
-> (ViewL1 a -> ViewL1 a -> Bool)
-> (ViewL1 a -> ViewL1 a -> Bool)
-> (ViewL1 a -> ViewL1 a -> Bool)
-> (ViewL1 a -> ViewL1 a -> Bool)
-> (ViewL1 a -> ViewL1 a -> ViewL1 a)
-> (ViewL1 a -> ViewL1 a -> ViewL1 a)
-> Ord (ViewL1 a)
ViewL1 a -> ViewL1 a -> Bool
ViewL1 a -> ViewL1 a -> Ordering
ViewL1 a -> ViewL1 a -> ViewL1 a
forall a.
Eq a =>
(a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> a)
-> (a -> a -> a)
-> Ord a
forall a. Ord a => Eq (ViewL1 a)
forall a. Ord a => ViewL1 a -> ViewL1 a -> Bool
forall a. Ord a => ViewL1 a -> ViewL1 a -> Ordering
forall a. Ord a => ViewL1 a -> ViewL1 a -> ViewL1 a
$ccompare :: forall a. Ord a => ViewL1 a -> ViewL1 a -> Ordering
compare :: ViewL1 a -> ViewL1 a -> Ordering
$c< :: forall a. Ord a => ViewL1 a -> ViewL1 a -> Bool
< :: ViewL1 a -> ViewL1 a -> Bool
$c<= :: forall a. Ord a => ViewL1 a -> ViewL1 a -> Bool
<= :: ViewL1 a -> ViewL1 a -> Bool
$c> :: forall a. Ord a => ViewL1 a -> ViewL1 a -> Bool
> :: ViewL1 a -> ViewL1 a -> Bool
$c>= :: forall a. Ord a => ViewL1 a -> ViewL1 a -> Bool
>= :: ViewL1 a -> ViewL1 a -> Bool
$cmax :: forall a. Ord a => ViewL1 a -> ViewL1 a -> ViewL1 a
max :: ViewL1 a -> ViewL1 a -> ViewL1 a
$cmin :: forall a. Ord a => ViewL1 a -> ViewL1 a -> ViewL1 a
min :: ViewL1 a -> ViewL1 a -> ViewL1 a
Ord,(forall a b. (a -> b) -> ViewL1 a -> ViewL1 b)
-> (forall a b. a -> ViewL1 b -> ViewL1 a) -> Functor ViewL1
forall a b. a -> ViewL1 b -> ViewL1 a
forall a b. (a -> b) -> ViewL1 a -> ViewL1 b
forall (f :: * -> *).
(forall a b. (a -> b) -> f a -> f b)
-> (forall a b. a -> f b -> f a) -> Functor f
$cfmap :: forall a b. (a -> b) -> ViewL1 a -> ViewL1 b
fmap :: forall a b. (a -> b) -> ViewL1 a -> ViewL1 b
$c<$ :: forall a b. a -> ViewL1 b -> ViewL1 a
<$ :: forall a b. a -> ViewL1 b -> ViewL1 a
Functor,Functor ViewL1
Foldable ViewL1
(Functor ViewL1, Foldable ViewL1) =>
(forall (f :: * -> *) a b.
 Applicative f =>
 (a -> f b) -> ViewL1 a -> f (ViewL1 b))
-> (forall (f :: * -> *) a.
    Applicative f =>
    ViewL1 (f a) -> f (ViewL1 a))
-> (forall (m :: * -> *) a b.
    Monad m =>
    (a -> m b) -> ViewL1 a -> m (ViewL1 b))
-> (forall (m :: * -> *) a.
    Monad m =>
    ViewL1 (m a) -> m (ViewL1 a))
-> Traversable ViewL1
forall (t :: * -> *).
(Functor t, Foldable t) =>
(forall (f :: * -> *) a b.
 Applicative f =>
 (a -> f b) -> t a -> f (t b))
-> (forall (f :: * -> *) a. Applicative f => t (f a) -> f (t a))
-> (forall (m :: * -> *) a b.
    Monad m =>
    (a -> m b) -> t a -> m (t b))
-> (forall (m :: * -> *) a. Monad m => t (m a) -> m (t a))
-> Traversable t
forall (m :: * -> *) a. Monad m => ViewL1 (m a) -> m (ViewL1 a)
forall (f :: * -> *) a.
Applicative f =>
ViewL1 (f a) -> f (ViewL1 a)
forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> ViewL1 a -> m (ViewL1 b)
forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> ViewL1 a -> f (ViewL1 b)
$ctraverse :: forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> ViewL1 a -> f (ViewL1 b)
traverse :: forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> ViewL1 a -> f (ViewL1 b)
$csequenceA :: forall (f :: * -> *) a.
Applicative f =>
ViewL1 (f a) -> f (ViewL1 a)
sequenceA :: forall (f :: * -> *) a.
Applicative f =>
ViewL1 (f a) -> f (ViewL1 a)
$cmapM :: forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> ViewL1 a -> m (ViewL1 b)
mapM :: forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> ViewL1 a -> m (ViewL1 b)
$csequence :: forall (m :: * -> *) a. Monad m => ViewL1 (m a) -> m (ViewL1 a)
sequence :: forall (m :: * -> *) a. Monad m => ViewL1 (m a) -> m (ViewL1 a)
Traversable,(forall x. ViewL1 a -> Rep (ViewL1 a) x)
-> (forall x. Rep (ViewL1 a) x -> ViewL1 a) -> Generic (ViewL1 a)
forall x. Rep (ViewL1 a) x -> ViewL1 a
forall x. ViewL1 a -> Rep (ViewL1 a) x
forall a.
(forall x. a -> Rep a x) -> (forall x. Rep a x -> a) -> Generic a
forall a x. Rep (ViewL1 a) x -> ViewL1 a
forall a x. ViewL1 a -> Rep (ViewL1 a) x
$cfrom :: forall a x. ViewL1 a -> Rep (ViewL1 a) x
from :: forall x. ViewL1 a -> Rep (ViewL1 a) x
$cto :: forall a x. Rep (ViewL1 a) x -> ViewL1 a
to :: forall x. Rep (ViewL1 a) x -> ViewL1 a
Generic)

instance NFData a => NFData (ViewL1 a)

type instance Index   (ViewL1 a) = Int
type instance IxValue (ViewL1 a) = a

instance Ixed (ViewL1 a) where
  ix :: Index (ViewL1 a) -> Traversal' (ViewL1 a) (IxValue (ViewL1 a))
ix Index (ViewL1 a)
i IxValue (ViewL1 a) -> f (IxValue (ViewL1 a))
f (a
x :<< Seq a
xs)
    | Int
Index (ViewL1 a)
i Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
0    = (a -> Seq a -> ViewL1 a
forall a. a -> Seq a -> ViewL1 a
:<< Seq a
xs) (a -> ViewL1 a) -> f a -> f (ViewL1 a)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> IxValue (ViewL1 a) -> f (IxValue (ViewL1 a))
f a
IxValue (ViewL1 a)
x
    | Bool
otherwise = (a
x a -> Seq a -> ViewL1 a
forall a. a -> Seq a -> ViewL1 a
:<<)  (Seq a -> ViewL1 a) -> f (Seq a) -> f (ViewL1 a)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Index (Seq a) -> Traversal' (Seq a) (IxValue (Seq a))
forall m. Ixed m => Index m -> Traversal' m (IxValue m)
ix (Int
Index (ViewL1 a)
iInt -> Int -> Int
forall a. Num a => a -> a -> a
-Int
1) IxValue (Seq a) -> f (IxValue (Seq a))
IxValue (ViewL1 a) -> f (IxValue (ViewL1 a))
f Seq a
xs
  {-# INLINE ix #-}

instance Foldable ViewL1 where
  foldMap :: forall m a. Monoid m => (a -> m) -> ViewL1 a -> m
foldMap a -> m
f (a
x :<< Seq a
xs) = a -> m
f a
x m -> m -> m
forall a. Semigroup a => a -> a -> a
<> (a -> m) -> Seq a -> m
forall m a. Monoid m => (a -> m) -> Seq a -> m
forall (t :: * -> *) m a.
(Foldable t, Monoid m) =>
(a -> m) -> t a -> m
foldMap a -> m
f Seq a
xs
  {-# INLINE foldMap #-}
  length :: forall a. ViewL1 a -> Int
length (a
_ :<< Seq a
xs) = Int
1 Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Seq a -> Int
forall a. Seq a -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length Seq a
xs
  {-# INLINE length #-}
  null :: forall a. ViewL1 a -> Bool
null ViewL1 a
_ = Bool
False
  {-# INLINE null #-}

instance Foldable1 ViewL1 where
  foldMap1 :: forall m a. Semigroup m => (a -> m) -> ViewL1 a -> m
foldMap1 a -> m
f (a
a :<< Seq a
as) = case (a -> Maybe m) -> Seq a -> Maybe m
forall m a. Monoid m => (a -> m) -> Seq a -> m
forall (t :: * -> *) m a.
(Foldable t, Monoid m) =>
(a -> m) -> t a -> m
foldMap (m -> Maybe m
forall a. a -> Maybe a
Just (m -> Maybe m) -> (a -> m) -> a -> Maybe m
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> m
f) Seq a
as of
    Maybe m
Nothing -> a -> m
f a
a
    Just m
b  -> a -> m
f a
a m -> m -> m
forall a. Semigroup a => a -> a -> a
<> m
b
  {-# INLINE foldMap1 #-}

instance Traversable1 ViewL1 where
  traverse1 :: forall (f :: * -> *) a b.
Apply f =>
(a -> f b) -> ViewL1 a -> f (ViewL1 b)
traverse1 a -> f b
f (a
a :<< Seq a
as) = b -> Seq b -> ViewL1 b
forall a. a -> Seq a -> ViewL1 a
(:<<) (b -> Seq b -> ViewL1 b) -> f b -> f (Seq b -> ViewL1 b)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> a -> f b
f a
a f (Seq b -> ViewL1 b) -> MaybeApply f (Seq b) -> f (ViewL1 b)
forall (f :: * -> *) a b.
Apply f =>
f (a -> b) -> MaybeApply f a -> f b
<.*> (a -> f b) -> Seq a -> MaybeApply f (Seq b)
forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Apply f) =>
(a -> f b) -> t a -> MaybeApply f (t b)
traverse1Maybe a -> f b
f Seq a
as
  {-# INLINE traverse1 #-}

instance FunctorWithIndex Int ViewL1
instance FoldableWithIndex Int ViewL1
instance TraversableWithIndex Int ViewL1

instance Foldable1WithIndex Int ViewL1 where
  ifoldMap1 :: forall m a. Semigroup m => (Int -> a -> m) -> ViewL1 a -> m
ifoldMap1 Int -> a -> m
f (a
a :<< Seq a
as) = case (Int -> a -> Maybe m) -> Seq a -> Maybe m
forall m a. Monoid m => (Int -> a -> m) -> Seq a -> m
forall i (f :: * -> *) m a.
(FoldableWithIndex i f, Monoid m) =>
(i -> a -> m) -> f a -> m
ifoldMap (\Int
i -> m -> Maybe m
forall a. a -> Maybe a
Just (m -> Maybe m) -> (a -> m) -> a -> Maybe m
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Int -> a -> m
f (Int
iInt -> Int -> Int
forall a. Num a => a -> a -> a
+Int
1)) Seq a
as of
    Maybe m
Nothing -> Int -> a -> m
f Int
0 a
a
    Just m
b  -> Int -> a -> m
f Int
0 a
a m -> m -> m
forall a. Semigroup a => a -> a -> a
<> m
b
  {-# INLINE ifoldMap1 #-}

-- instance Traversable1WithIndex Int ViewL1


instance Semigroup (ViewL1 a) where
  (a
a :<< Seq a
as) <> :: ViewL1 a -> ViewL1 a -> ViewL1 a
<> (a
b :<< Seq a
bs) = a
a a -> Seq a -> ViewL1 a
forall a. a -> Seq a -> ViewL1 a
:<< (Seq a
as Seq a -> Seq a -> Seq a
forall a. Semigroup a => a -> a -> a
<> (a
b a -> Seq a -> Seq a
forall a. a -> Seq a -> Seq a
:<| Seq a
bs))
  {-# INLINE (<>) #-}

instance HasFromFoldable1 ViewL1 where
  fromNonEmpty :: forall a. NonEmpty a -> ViewL1 a
fromNonEmpty (a
a :| [a]
as) = a
a a -> Seq a -> ViewL1 a
forall a. a -> Seq a -> ViewL1 a
:<< [Item (Seq a)] -> Seq a
forall l. IsList l => [Item l] -> l
fromList [a]
[Item (Seq a)]
as
  {-# INLINE fromNonEmpty #-}

instance IsList (ViewL1 a) where
  type Item (ViewL1 a) = a
  toList :: ViewL1 a -> [Item (ViewL1 a)]
toList = ViewL1 a -> [a]
ViewL1 a -> [Item (ViewL1 a)]
forall a. ViewL1 a -> [a]
forall (t :: * -> *) a. Foldable t => t a -> [a]
F.toList
  {-# INLINE toList #-}
  fromList :: [Item (ViewL1 a)] -> ViewL1 a
fromList = ViewL1 a
-> (NonEmpty a -> ViewL1 a) -> Maybe (NonEmpty a) -> ViewL1 a
forall b a. b -> (a -> b) -> Maybe a -> b
maybe (String -> ViewL1 a
forall a. HasCallStack => String -> a
error String
"ViewL1 fromList; empty List") NonEmpty a -> ViewL1 a
forall a. NonEmpty a -> ViewL1 a
forall (f :: * -> *) a. HasFromFoldable1 f => NonEmpty a -> f a
fromNonEmpty (Maybe (NonEmpty a) -> ViewL1 a)
-> ([a] -> Maybe (NonEmpty a)) -> [a] -> ViewL1 a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [a] -> Maybe (NonEmpty a)
forall a. [a] -> Maybe (NonEmpty a)
NonEmpty.nonEmpty
  {-# INLINE fromList #-}

instance Reversing (ViewL1 a) where
  reversing :: ViewL1 a -> ViewL1 a
reversing (a
x :<< Seq a
s) = ViewR1 a -> ViewL1 a
forall a. ViewR1 a -> ViewL1 a
viewl1 (ViewR1 a -> ViewL1 a) -> ViewR1 a -> ViewL1 a
forall a b. (a -> b) -> a -> b
$ Seq a -> Seq a
forall a. Seq a -> Seq a
Sequence.reverse Seq a
s Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
x

--------------------------------------------------------------------------------

-- | NonEmpty ViewR
data ViewR1 a = Seq a :>> a
  deriving stock (Int -> ViewR1 a -> ShowS
[ViewR1 a] -> ShowS
ViewR1 a -> String
(Int -> ViewR1 a -> ShowS)
-> (ViewR1 a -> String) -> ([ViewR1 a] -> ShowS) -> Show (ViewR1 a)
forall a. Show a => Int -> ViewR1 a -> ShowS
forall a. Show a => [ViewR1 a] -> ShowS
forall a. Show a => ViewR1 a -> String
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
$cshowsPrec :: forall a. Show a => Int -> ViewR1 a -> ShowS
showsPrec :: Int -> ViewR1 a -> ShowS
$cshow :: forall a. Show a => ViewR1 a -> String
show :: ViewR1 a -> String
$cshowList :: forall a. Show a => [ViewR1 a] -> ShowS
showList :: [ViewR1 a] -> ShowS
Show,ReadPrec [ViewR1 a]
ReadPrec (ViewR1 a)
Int -> ReadS (ViewR1 a)
ReadS [ViewR1 a]
(Int -> ReadS (ViewR1 a))
-> ReadS [ViewR1 a]
-> ReadPrec (ViewR1 a)
-> ReadPrec [ViewR1 a]
-> Read (ViewR1 a)
forall a. Read a => ReadPrec [ViewR1 a]
forall a. Read a => ReadPrec (ViewR1 a)
forall a. Read a => Int -> ReadS (ViewR1 a)
forall a. Read a => ReadS [ViewR1 a]
forall a.
(Int -> ReadS a)
-> ReadS [a] -> ReadPrec a -> ReadPrec [a] -> Read a
$creadsPrec :: forall a. Read a => Int -> ReadS (ViewR1 a)
readsPrec :: Int -> ReadS (ViewR1 a)
$creadList :: forall a. Read a => ReadS [ViewR1 a]
readList :: ReadS [ViewR1 a]
$creadPrec :: forall a. Read a => ReadPrec (ViewR1 a)
readPrec :: ReadPrec (ViewR1 a)
$creadListPrec :: forall a. Read a => ReadPrec [ViewR1 a]
readListPrec :: ReadPrec [ViewR1 a]
Read,ViewR1 a -> ViewR1 a -> Bool
(ViewR1 a -> ViewR1 a -> Bool)
-> (ViewR1 a -> ViewR1 a -> Bool) -> Eq (ViewR1 a)
forall a. Eq a => ViewR1 a -> ViewR1 a -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
$c== :: forall a. Eq a => ViewR1 a -> ViewR1 a -> Bool
== :: ViewR1 a -> ViewR1 a -> Bool
$c/= :: forall a. Eq a => ViewR1 a -> ViewR1 a -> Bool
/= :: ViewR1 a -> ViewR1 a -> Bool
Eq,Eq (ViewR1 a)
Eq (ViewR1 a) =>
(ViewR1 a -> ViewR1 a -> Ordering)
-> (ViewR1 a -> ViewR1 a -> Bool)
-> (ViewR1 a -> ViewR1 a -> Bool)
-> (ViewR1 a -> ViewR1 a -> Bool)
-> (ViewR1 a -> ViewR1 a -> Bool)
-> (ViewR1 a -> ViewR1 a -> ViewR1 a)
-> (ViewR1 a -> ViewR1 a -> ViewR1 a)
-> Ord (ViewR1 a)
ViewR1 a -> ViewR1 a -> Bool
ViewR1 a -> ViewR1 a -> Ordering
ViewR1 a -> ViewR1 a -> ViewR1 a
forall a.
Eq a =>
(a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> a)
-> (a -> a -> a)
-> Ord a
forall a. Ord a => Eq (ViewR1 a)
forall a. Ord a => ViewR1 a -> ViewR1 a -> Bool
forall a. Ord a => ViewR1 a -> ViewR1 a -> Ordering
forall a. Ord a => ViewR1 a -> ViewR1 a -> ViewR1 a
$ccompare :: forall a. Ord a => ViewR1 a -> ViewR1 a -> Ordering
compare :: ViewR1 a -> ViewR1 a -> Ordering
$c< :: forall a. Ord a => ViewR1 a -> ViewR1 a -> Bool
< :: ViewR1 a -> ViewR1 a -> Bool
$c<= :: forall a. Ord a => ViewR1 a -> ViewR1 a -> Bool
<= :: ViewR1 a -> ViewR1 a -> Bool
$c> :: forall a. Ord a => ViewR1 a -> ViewR1 a -> Bool
> :: ViewR1 a -> ViewR1 a -> Bool
$c>= :: forall a. Ord a => ViewR1 a -> ViewR1 a -> Bool
>= :: ViewR1 a -> ViewR1 a -> Bool
$cmax :: forall a. Ord a => ViewR1 a -> ViewR1 a -> ViewR1 a
max :: ViewR1 a -> ViewR1 a -> ViewR1 a
$cmin :: forall a. Ord a => ViewR1 a -> ViewR1 a -> ViewR1 a
min :: ViewR1 a -> ViewR1 a -> ViewR1 a
Ord,(forall a b. (a -> b) -> ViewR1 a -> ViewR1 b)
-> (forall a b. a -> ViewR1 b -> ViewR1 a) -> Functor ViewR1
forall a b. a -> ViewR1 b -> ViewR1 a
forall a b. (a -> b) -> ViewR1 a -> ViewR1 b
forall (f :: * -> *).
(forall a b. (a -> b) -> f a -> f b)
-> (forall a b. a -> f b -> f a) -> Functor f
$cfmap :: forall a b. (a -> b) -> ViewR1 a -> ViewR1 b
fmap :: forall a b. (a -> b) -> ViewR1 a -> ViewR1 b
$c<$ :: forall a b. a -> ViewR1 b -> ViewR1 a
<$ :: forall a b. a -> ViewR1 b -> ViewR1 a
Functor,Functor ViewR1
Foldable ViewR1
(Functor ViewR1, Foldable ViewR1) =>
(forall (f :: * -> *) a b.
 Applicative f =>
 (a -> f b) -> ViewR1 a -> f (ViewR1 b))
-> (forall (f :: * -> *) a.
    Applicative f =>
    ViewR1 (f a) -> f (ViewR1 a))
-> (forall (m :: * -> *) a b.
    Monad m =>
    (a -> m b) -> ViewR1 a -> m (ViewR1 b))
-> (forall (m :: * -> *) a.
    Monad m =>
    ViewR1 (m a) -> m (ViewR1 a))
-> Traversable ViewR1
forall (t :: * -> *).
(Functor t, Foldable t) =>
(forall (f :: * -> *) a b.
 Applicative f =>
 (a -> f b) -> t a -> f (t b))
-> (forall (f :: * -> *) a. Applicative f => t (f a) -> f (t a))
-> (forall (m :: * -> *) a b.
    Monad m =>
    (a -> m b) -> t a -> m (t b))
-> (forall (m :: * -> *) a. Monad m => t (m a) -> m (t a))
-> Traversable t
forall (m :: * -> *) a. Monad m => ViewR1 (m a) -> m (ViewR1 a)
forall (f :: * -> *) a.
Applicative f =>
ViewR1 (f a) -> f (ViewR1 a)
forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> ViewR1 a -> m (ViewR1 b)
forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> ViewR1 a -> f (ViewR1 b)
$ctraverse :: forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> ViewR1 a -> f (ViewR1 b)
traverse :: forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> ViewR1 a -> f (ViewR1 b)
$csequenceA :: forall (f :: * -> *) a.
Applicative f =>
ViewR1 (f a) -> f (ViewR1 a)
sequenceA :: forall (f :: * -> *) a.
Applicative f =>
ViewR1 (f a) -> f (ViewR1 a)
$cmapM :: forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> ViewR1 a -> m (ViewR1 b)
mapM :: forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> ViewR1 a -> m (ViewR1 b)
$csequence :: forall (m :: * -> *) a. Monad m => ViewR1 (m a) -> m (ViewR1 a)
sequence :: forall (m :: * -> *) a. Monad m => ViewR1 (m a) -> m (ViewR1 a)
Traversable,(forall x. ViewR1 a -> Rep (ViewR1 a) x)
-> (forall x. Rep (ViewR1 a) x -> ViewR1 a) -> Generic (ViewR1 a)
forall x. Rep (ViewR1 a) x -> ViewR1 a
forall x. ViewR1 a -> Rep (ViewR1 a) x
forall a.
(forall x. a -> Rep a x) -> (forall x. Rep a x -> a) -> Generic a
forall a x. Rep (ViewR1 a) x -> ViewR1 a
forall a x. ViewR1 a -> Rep (ViewR1 a) x
$cfrom :: forall a x. ViewR1 a -> Rep (ViewR1 a) x
from :: forall x. ViewR1 a -> Rep (ViewR1 a) x
$cto :: forall a x. Rep (ViewR1 a) x -> ViewR1 a
to :: forall x. Rep (ViewR1 a) x -> ViewR1 a
Generic)

instance NFData a => NFData (ViewR1 a)

type instance Index   (ViewR1 a) = Int
type instance IxValue (ViewR1 a) = a

instance Ixed (ViewR1 a) where
  ix :: Index (ViewR1 a) -> Traversal' (ViewR1 a) (IxValue (ViewR1 a))
ix Index (ViewR1 a)
i IxValue (ViewR1 a) -> f (IxValue (ViewR1 a))
f (Seq a
xs :>> a
x)
    | Int
Index (ViewR1 a)
i Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Seq a -> Int
forall a. Seq a -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length Seq a
xs = (Seq a
xs Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>>) (a -> ViewR1 a) -> f a -> f (ViewR1 a)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> IxValue (ViewR1 a) -> f (IxValue (ViewR1 a))
f a
IxValue (ViewR1 a)
x
    | Bool
otherwise      = (Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
x)  (Seq a -> ViewR1 a) -> f (Seq a) -> f (ViewR1 a)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Index (Seq a) -> Traversal' (Seq a) (IxValue (Seq a))
forall m. Ixed m => Index m -> Traversal' m (IxValue m)
ix Index (Seq a)
Index (ViewR1 a)
i IxValue (Seq a) -> f (IxValue (Seq a))
IxValue (ViewR1 a) -> f (IxValue (ViewR1 a))
f Seq a
xs
  {-# INLINE ix #-}

instance Foldable ViewR1 where
  foldMap :: forall m a. Monoid m => (a -> m) -> ViewR1 a -> m
foldMap a -> m
f (Seq a
xs :>> a
x) = (a -> m) -> Seq a -> m
forall m a. Monoid m => (a -> m) -> Seq a -> m
forall (t :: * -> *) m a.
(Foldable t, Monoid m) =>
(a -> m) -> t a -> m
foldMap a -> m
f Seq a
xs m -> m -> m
forall a. Semigroup a => a -> a -> a
<> a -> m
f a
x
  {-# INLINE foldMap #-}
  length :: forall a. ViewR1 a -> Int
length (Seq a
xs :>> a
_) = Int
1 Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Seq a -> Int
forall a. Seq a -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length Seq a
xs
  {-# INLINE length #-}
  null :: forall a. ViewR1 a -> Bool
null ViewR1 a
_ = Bool
False
  {-# INLINE null #-}

instance Foldable1 ViewR1 where
  foldMap1 :: forall m a. Semigroup m => (a -> m) -> ViewR1 a -> m
foldMap1 a -> m
f (Seq a
as :>> a
a) = case (a -> Maybe m) -> Seq a -> Maybe m
forall m a. Monoid m => (a -> m) -> Seq a -> m
forall (t :: * -> *) m a.
(Foldable t, Monoid m) =>
(a -> m) -> t a -> m
foldMap (m -> Maybe m
forall a. a -> Maybe a
Just (m -> Maybe m) -> (a -> m) -> a -> Maybe m
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> m
f) Seq a
as of
    Maybe m
Nothing -> a -> m
f a
a
    Just m
b  -> m
b m -> m -> m
forall a. Semigroup a => a -> a -> a
<> a -> m
f a
a
  {-# INLINE foldMap1 #-}

instance Traversable1 ViewR1 where
  traverse1 :: forall (f :: * -> *) a b.
Apply f =>
(a -> f b) -> ViewR1 a -> f (ViewR1 b)
traverse1 a -> f b
f (Seq a
as :>> a
a) = Seq b -> b -> ViewR1 b
forall a. Seq a -> a -> ViewR1 a
(:>>) (Seq b -> b -> ViewR1 b)
-> MaybeApply f (Seq b) -> MaybeApply f (b -> ViewR1 b)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> (a -> f b) -> Seq a -> MaybeApply f (Seq b)
forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Apply f) =>
(a -> f b) -> t a -> MaybeApply f (t b)
traverse1Maybe a -> f b
f Seq a
as MaybeApply f (b -> ViewR1 b) -> f b -> f (ViewR1 b)
forall (f :: * -> *) a b.
Apply f =>
MaybeApply f (a -> b) -> f a -> f b
<*.> a -> f b
f a
a
  {-# INLINE traverse1 #-}

instance FunctorWithIndex Int ViewR1
instance FoldableWithIndex Int ViewR1
instance TraversableWithIndex Int ViewR1

instance Foldable1WithIndex Int ViewR1 where
  ifoldMap1 :: forall m a. Semigroup m => (Int -> a -> m) -> ViewR1 a -> m
ifoldMap1 Int -> a -> m
f (Seq a
as :>> a
a) = case (Int -> a -> Maybe m) -> Seq a -> Maybe m
forall m a. Monoid m => (Int -> a -> m) -> Seq a -> m
forall i (f :: * -> *) m a.
(FoldableWithIndex i f, Monoid m) =>
(i -> a -> m) -> f a -> m
ifoldMap (\Int
i -> m -> Maybe m
forall a. a -> Maybe a
Just (m -> Maybe m) -> (a -> m) -> a -> Maybe m
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Int -> a -> m
f Int
i) Seq a
as of
    Maybe m
Nothing -> Int -> a -> m
f Int
0 a
a
    Just m
b  -> m
b m -> m -> m
forall a. Semigroup a => a -> a -> a
<> Int -> a -> m
f (Seq a -> Int
forall a. Seq a -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length Seq a
as) a
a
  {-# INLINE ifoldMap1 #-}

-- instance Traversable1WithIndex Int ViewR1


instance Semigroup (ViewR1 a) where
  (Seq a
as :>> a
a) <> :: ViewR1 a -> ViewR1 a -> ViewR1 a
<> (Seq a
bs :>> a
b) = ((Seq a
as Seq a -> a -> Seq a
forall a. Seq a -> a -> Seq a
:|> a
a) Seq a -> Seq a -> Seq a
forall a. Semigroup a => a -> a -> a
<> Seq a
bs) Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
b
  {-# INLINE (<>) #-}

instance HasFromFoldable1 ViewR1 where
  fromNonEmpty :: forall a. NonEmpty a -> ViewR1 a
fromNonEmpty (a
a :| [a]
as) = case NonEmpty a -> ViewR1 a
forall a. NonEmpty a -> ViewR1 a
forall (f :: * -> *) a. HasFromFoldable1 f => NonEmpty a -> f a
fromNonEmpty (NonEmpty a -> ViewR1 a) -> Maybe (NonEmpty a) -> Maybe (ViewR1 a)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> [a] -> Maybe (NonEmpty a)
forall a. [a] -> Maybe (NonEmpty a)
NonEmpty.nonEmpty [a]
as of
                             Maybe (ViewR1 a)
Nothing          -> Seq a
forall a. Seq a
Sequence.empty Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
a
                             Just (Seq a
as' :>> a
x) -> (a
a a -> Seq a -> Seq a
forall a. a -> Seq a -> Seq a
:<| Seq a
as') Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
x
  {-# INLINE fromNonEmpty #-}

instance IsList (ViewR1 a) where
  type Item (ViewR1 a) = a
  toList :: ViewR1 a -> [Item (ViewR1 a)]
toList = ViewR1 a -> [a]
ViewR1 a -> [Item (ViewR1 a)]
forall a. ViewR1 a -> [a]
forall (t :: * -> *) a. Foldable t => t a -> [a]
F.toList
  {-# INLINE toList #-}
  fromList :: [Item (ViewR1 a)] -> ViewR1 a
fromList = ViewR1 a
-> (NonEmpty a -> ViewR1 a) -> Maybe (NonEmpty a) -> ViewR1 a
forall b a. b -> (a -> b) -> Maybe a -> b
maybe (String -> ViewR1 a
forall a. HasCallStack => String -> a
error String
"ViewR1 fromList; empty List") NonEmpty a -> ViewR1 a
forall a. NonEmpty a -> ViewR1 a
forall (f :: * -> *) a. HasFromFoldable1 f => NonEmpty a -> f a
fromNonEmpty (Maybe (NonEmpty a) -> ViewR1 a)
-> ([a] -> Maybe (NonEmpty a)) -> [a] -> ViewR1 a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [a] -> Maybe (NonEmpty a)
forall a. [a] -> Maybe (NonEmpty a)
NonEmpty.nonEmpty
  {-# INLINE fromList #-}

instance Reversing (ViewR1 a) where
  reversing :: ViewR1 a -> ViewR1 a
reversing (Seq a
s :>> a
x) = ViewL1 a -> ViewR1 a
forall a. ViewL1 a -> ViewR1 a
viewr1 (ViewL1 a -> ViewR1 a) -> ViewL1 a -> ViewR1 a
forall a b. (a -> b) -> a -> b
$ a
x a -> Seq a -> ViewL1 a
forall a. a -> Seq a -> ViewL1 a
:<< Seq a -> Seq a
forall a. Seq a -> Seq a
Sequence.reverse Seq a
s


-- | snoc an element to the right
(|>>) :: ViewR1 a -> a -> ViewR1 a
(Seq a
ys :>> a
y) |>> :: forall a. ViewR1 a -> a -> ViewR1 a
|>> a
x = (Seq a
ys Seq a -> a -> Seq a
forall a. Seq a -> a -> Seq a
:|> a
y) Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
x

infixl 5 |>>
infixl 5 <>>

-- | Append a Sequence to a ViewR1
(<>>)               :: ViewR1 a -> Seq a -> ViewR1 a
l :: ViewR1 a
l@(Seq a
ys :>> a
y) <>> :: forall a. ViewR1 a -> Seq a -> ViewR1 a
<>> Seq a
rs = case Seq a -> ViewR a
forall a. Seq a -> ViewR a
Sequence.viewr Seq a
rs of
                        ViewR a
Sequence.EmptyR   -> ViewR1 a
l
                        Seq a
rs' Sequence.:> a
r -> (Seq a
ys Seq a -> Seq a -> Seq a
forall a. Semigroup a => a -> a -> a
<> (a
y a -> Seq a -> Seq a
forall a. a -> Seq a -> Seq a
:<| Seq a
rs')) Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
r




-- | View the leftmost element
viewl1            :: ViewR1 a -> ViewL1 a
viewl1 :: forall a. ViewR1 a -> ViewL1 a
viewl1 (Seq a
xs :>> a
r) = case Seq a -> ViewL a
forall a. Seq a -> ViewL a
Sequence.viewl Seq a
xs of
                      ViewL a
Sequence.EmptyL   -> a
r a -> Seq a -> ViewL1 a
forall a. a -> Seq a -> ViewL1 a
:<< Seq a
forall a. Seq a
Sequence.empty
                      a
l Sequence.:< Seq a
mid -> a
l a -> Seq a -> ViewL1 a
forall a. a -> Seq a -> ViewL1 a
:<< (Seq a
mid Seq a -> a -> Seq a
forall a. Seq a -> a -> Seq a
:|> a
r)

-- | View the rightmost element
viewr1            :: ViewL1 a -> ViewR1 a
viewr1 :: forall a. ViewL1 a -> ViewR1 a
viewr1 (a
l :<< Seq a
ls) = case Seq a -> ViewR a
forall a. Seq a -> ViewR a
Sequence.viewr Seq a
ls of
                      ViewR a
Sequence.EmptyR   -> Seq a
forall a. Seq a
Sequence.empty Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
l
                      Seq a
mid Sequence.:> a
r -> (a
l a -> Seq a -> Seq a
forall a. a -> Seq a -> Seq a
:<| Seq a
mid)    Seq a -> a -> ViewR1 a
forall a. Seq a -> a -> ViewR1 a
:>> a
r


--------------------------------------------------------------------------------

-- | Given an index i, and a viewL1 s, attempts to split s at index i. Returns nothing if
-- the index is out of range.
splitL1At             :: Int -> ViewL1 a -> Maybe (Seq a, a, Seq a)
splitL1At :: forall a. Int -> ViewL1 a -> Maybe (Seq a, a, Seq a)
splitL1At Int
i (a
x :<< Seq a
s) = Int -> Seq a -> Maybe (Seq a)
forall (t :: * -> *) a. Foldable t => Int -> t a -> Maybe (t a)
clampRange Int
i (a
x a -> Seq a -> Seq a
forall s a. Cons s s a a => a -> s -> s
<| Seq a
s) Maybe (Seq a)
-> (Seq a -> (Seq a, a, Seq a)) -> Maybe (Seq a, a, Seq a)
forall (f :: * -> *) a b. Functor f => f a -> (a -> b) -> f b
<&> \Seq a
s' -> case Int -> Seq a -> (Seq a, Seq a)
forall a. Int -> Seq a -> (Seq a, Seq a)
Sequence.splitAt Int
i Seq a
s' of
  (Seq a
pref, a
y :<| Seq a
suff) -> (Seq a
pref, a
y, Seq a
suff)
  (Seq a, Seq a)
_                  -> String -> (Seq a, a, Seq a)
forall a. HasCallStack => String -> a
error String
"splitL1At: absurd"

-- | Given an index i, and a viewL1 s, attempts to split s at index i. Returns nothing if
-- the index is out of range.
splitR1At             :: Int -> ViewR1 a -> Maybe (Seq a, a, Seq a)
splitR1At :: forall a. Int -> ViewR1 a -> Maybe (Seq a, a, Seq a)
splitR1At Int
i (Seq a
s :>> a
x) = Int -> Seq a -> Maybe (Seq a)
forall (t :: * -> *) a. Foldable t => Int -> t a -> Maybe (t a)
clampRange Int
i (Seq a
s Seq a -> a -> Seq a
forall s a. Snoc s s a a => s -> a -> s
|> a
x) Maybe (Seq a)
-> (Seq a -> (Seq a, a, Seq a)) -> Maybe (Seq a, a, Seq a)
forall (f :: * -> *) a b. Functor f => f a -> (a -> b) -> f b
<&> \Seq a
s' -> case Int -> Seq a -> (Seq a, Seq a)
forall a. Int -> Seq a -> (Seq a, Seq a)
Sequence.splitAt Int
i Seq a
s' of
  (Seq a
pref, a
y :<| Seq a
suff) -> (Seq a
pref, a
y, Seq a
suff)
  (Seq a, Seq a)
_                  -> String -> (Seq a, a, Seq a)
forall a. HasCallStack => String -> a
error String
"splitR1At: absurd"

-- | Helper to make sure the index is within range.
clampRange :: Foldable t => Int -> t a -> Maybe (t a)
clampRange :: forall (t :: * -> *) a. Foldable t => Int -> t a -> Maybe (t a)
clampRange Int
i t a
s
  | Int
i Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< Int
0           = Maybe (t a)
forall a. Maybe a
Nothing
  | Int
i Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
>= t a -> Int
forall a. t a -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
F.length t a
s = Maybe (t a)
forall a. Maybe a
Nothing
  | Bool
otherwise       = t a -> Maybe (t a)
forall a. a -> Maybe a
Just t a
s

--------------------------------------------------------------------------------





-- class CanCons s t a | s -> a, t -> a where
--   -- | This class provides a way to attach elements on the left side of a structure in a
--   -- flexible manner.
--   cons1 :: a -> s -> t

-- class CanUncons s t a | s -> a, t -> a where
--   -- | This class provides a way to detach elements on the left side of a structure in a
--   -- flexible manner.
--   uncons1 :: t -> (a, s)

-- class CanSnoc s t a | s -> a, t -> a where
--   -- | This class provides a way to attach elements on the left side of a structure in a
--   -- flexible manner.
--   snoc1 :: s -> a -> t

-- class CanUnsnoc s t a | s -> a, t -> a where
--   -- | This class provides a way to detach elements on the left side of a structure in a
--   -- flexible manner.
--   unsnoc1 :: t -> (s, a)

-- instance CanCons (Seq a) (ViewL1 a) a where
--   cons1 = (:<<)

-- instance CanCons (ViewL1 a) (ViewL1 a) a where
--   cons1 x (y :<< ys) = x :<< (y :<| ys)

-- instance CanUncons (Seq a) (ViewL1 a) a where
--   uncons1 (a :<< as) = (a, as)

-- class Cons1 s t a | s -> a
--                   , s -> t where
--   -- | This class provides a way to attach or detach elements on the left side of a
--   -- structure in a flexible manner.
--   _Cons1 :: Iso' s (a, t)

-- instance Cons1 (ViewL1 a) (Seq a) a where
--   _Cons1 = iso (\(a :<< as) -> (a, as)) (uncurry (:<<))

-- instance Cons1 (ViewR1 a) (Seq a) a where
--   _Cons1 = iso (\(as :>> r) -> case Sequence.viewl as of
--                                  Sequence.EmptyL     -> (r, Sequence.empty)
--                                  (l Sequence.:< mid) -> (l, mid :|> r))
--                (\(l,as) -> case Sequence.viewr as of
--                              Sequence.EmptyR     -> Sequence.empty :>> l
--                              (mid Sequence.:> r) -> (l :<| mid) :>> r)



-- instance Cons (ViewR1 a) (Identity (Seq b)) a b where
--   _Cons = prism (\(b, Identity seqB) -> Identity (b :<| seqB))
--                 (\(as :>> a) -> case Sequence.viewl as of
--                                   Sequence.EmptyL            -> (a, _)
--                                   (x Sequence.EmptyL.:<| s') -> _
--                 )


  -- foo bar
  --   where
  --     foo :: (b, ViewR1 b) -> ViewR1 b

  --     bar :: Identity (Seq a) -> Either (ViewR1 b) a

  -- (\(b, t :|> b') -> )


  -- (\(b,Identity t) -> b :<| t) (\(a :<< _) -> Left a)

-- instance Snoc (ViewR1 a) (Identity (Seq b)) a b where
--   _Snoc = prism (\(Identity t,b) -> t :|> b) (\(_ :>> a) -> Left a)




-- xs |>> x



-- class Cons1 s t a b | s -> a
--                     , t -> b
--                     , s b  -> t
--                     , t a  -> s  where
--   -- | This class provides a way to attach or detach elements on the left side of a
--   -- structure in a flexible manner.
--   _Cons1 :: Iso s t (a, Maybe s) (b, Maybe t)


-- cons1 :: Cons1 s t s' t' a b =>



-- instance Cons1 (ViewL1 a) (ViewL1 b) a b where
--   _Cons1 = iso (\(x :<< xs) -> (x,xs)

--                )





--            (uncurry (:<<))
--   {-# INLINE _Cons1 #-}

-- instance Cons1 (ViewR1 a) (ViewR1 b) (Seq a) (Seq b) a b where
--   _Cons1 = iso (\(xs :>> l) -> case Sequence.viewl xs of
--                                  Sequence.EmptyL     -> (l,xs)
--                                  (f Sequence.:< xs') -> (f,xs' :|> l))
--                (\(f,xs) -> case Sequence.viewr xs of
--                              Sequence.EmptyR     -> xs :>> f
--                              (xs' Sequence.:> l) -> (f :<| xs') :>> l)
--   {-# INLINE _Cons1 #-}