------------------------------------------------------------------------
-- |
-- Module           : Data.Parameterized.TraversableFC
-- Copyright        : (c) Galois, Inc 2014-2015
-- Maintainer       : Joe Hendrix <jhendrix@galois.com>
-- Description      : Traversing structures having a single parametric type followed by a fixed kind.
--
-- This module declares classes for working with structures that accept
-- a parametric type parameter followed by some fixed kind.
------------------------------------------------------------------------
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE Trustworthy #-}
{-# LANGUAGE TypeOperators #-}
module Data.Parameterized.TraversableFC
  ( TestEqualityFC(..)
  , OrdFC(..)
  , ShowFC(..)
  , HashableFC(..)
  , FunctorFC(..)
  , FoldableFC(..)
  , foldlMFC
  , foldlMFC'
  , foldrMFC
  , foldrMFC'
  , TraversableFC(..)
  , traverseFC_
  , forMFC_
  , forFC_
  , forFC
  , fmapFCDefault
  , foldMapFCDefault
  , allFC
  , anyFC
  , lengthFC
  ) where

import Control.Applicative (Const(..) )
import Control.Monad.Identity ( Identity (..) )
import Data.Coerce
import Data.Monoid
import GHC.Exts (build)
import Data.Type.Equality

import Data.Parameterized.Classes

-- | A parameterized type that is a function on all instances.
class FunctorFC (t :: (k -> *) -> l -> *) where
  fmapFC :: forall f g. (forall x. f x -> g x) ->
                        (forall x. t f x -> t g x)

-- | A parameterized class for types which can be shown, when given
--   functions to show parameterized subterms.
class ShowFC (t :: (k -> *) -> l -> *) where
  {-# MINIMAL showFC | showsPrecFC #-}

  showFC :: forall f. (forall x. f x -> String)
         -> (forall x. t f x -> String)
  showFC forall (x :: k). f x -> String
sh t f x
x = (forall (x :: k). Int -> f x -> ShowS) -> Int -> t f x -> ShowS
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *).
ShowFC t =>
(forall (x :: k). Int -> f x -> ShowS)
-> forall (x :: l). Int -> t f x -> ShowS
showsPrecFC (\Int
_prec f x
z String
rest -> f x -> String
forall (x :: k). f x -> String
sh f x
z String -> ShowS
forall a. [a] -> [a] -> [a]
++ String
rest) Int
0 t f x
x []

  showsPrecFC :: forall f. (forall x. Int -> f x -> ShowS) ->
                           (forall x. Int -> t f x -> ShowS)
  showsPrecFC forall (x :: k). Int -> f x -> ShowS
sh Int
_prec t f x
x String
rest = (forall (x :: k). f x -> String) -> t f x -> String
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *).
ShowFC t =>
(forall (x :: k). f x -> String)
-> forall (x :: l). t f x -> String
showFC (\f x
z -> Int -> f x -> ShowS
forall (x :: k). Int -> f x -> ShowS
sh Int
0 f x
z []) t f x
x String -> ShowS
forall a. [a] -> [a] -> [a]
++ String
rest


-- | A parameterized class for types which can be hashed, when given
--   functions to hash parameterized subterms.
class HashableFC (t :: (k -> *) -> l -> *) where
  hashWithSaltFC :: forall f. (forall x. Int -> f x -> Int) ->
                              (forall x. Int -> t f x -> Int)

-- | A parameterized class for types which can be tested for parameterized equality,
--   when given an equality test for subterms.
class TestEqualityFC (t :: (k -> *) -> l -> *) where
  testEqualityFC :: forall f. (forall x y. f x -> f y -> (Maybe (x :~: y))) ->
                              (forall x y. t f x -> t f y -> (Maybe (x :~: y)))

-- | A parameterized class for types which can be tested for parameterized ordering,
--   when given an comparison test for subterms.
class TestEqualityFC t => OrdFC (t :: (k -> *) -> l -> *) where
  compareFC :: forall f. (forall x y. f x -> f y -> OrderingF x y) ->
                         (forall x y. t f x -> t f y -> OrderingF x y)

------------------------------------------------------------------------
-- FoldableF

-- | This is a coercion used to avoid overhead associated
-- with function composition.
(#.) :: Coercible b c => (b -> c) -> (a -> b) -> (a -> c)
#. :: (b -> c) -> (a -> b) -> a -> c
(#.) b -> c
_f = (a -> b) -> a -> c
coerce

-- | This is a generalization of the 'Foldable' class to
-- structures over parameterized terms.
class FoldableFC (t :: (k -> *) -> l -> *) where
  {-# MINIMAL foldMapFC | foldrFC #-}

  -- | Map each element of the structure to a monoid,
  -- and combine the results.
  foldMapFC :: forall f m. Monoid m => (forall x. f x -> m) -> (forall x. t f x -> m)
  foldMapFC forall (x :: k). f x -> m
f = (forall (x :: k). f x -> m -> m) -> m -> t f x -> m
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). f x -> b -> b)
-> forall (x :: l). b -> t f x -> b
foldrFC (m -> m -> m
forall a. Monoid a => a -> a -> a
mappend (m -> m -> m) -> (f x -> m) -> f x -> m -> m
forall b c a. (b -> c) -> (a -> b) -> a -> c
. f x -> m
forall (x :: k). f x -> m
f) m
forall a. Monoid a => a
mempty

  -- | Right-associative fold of a structure.
  foldrFC :: forall f b. (forall x. f x -> b -> b) -> (forall x. b -> t f x -> b)
  foldrFC forall (x :: k). f x -> b -> b
f b
z t f x
t = Endo b -> b -> b
forall a. Endo a -> a -> a
appEndo ((forall (x :: k). f x -> Endo b) -> t f x -> Endo b
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) m.
(FoldableFC t, Monoid m) =>
(forall (x :: k). f x -> m) -> forall (x :: l). t f x -> m
foldMapFC ((b -> b) -> Endo b
forall a. (a -> a) -> Endo a
Endo ((b -> b) -> Endo b) -> (f x -> b -> b) -> f x -> Endo b
forall b c a. Coercible b c => (b -> c) -> (a -> b) -> a -> c
#. f x -> b -> b
forall (x :: k). f x -> b -> b
f) t f x
t) b
z

  -- | Left-associative fold of a structure.
  foldlFC :: forall f b. (forall x. b -> f x -> b) -> (forall x. b -> t f x -> b)
  foldlFC forall (x :: k). b -> f x -> b
f b
z t f x
t = Endo b -> b -> b
forall a. Endo a -> a -> a
appEndo (Dual (Endo b) -> Endo b
forall a. Dual a -> a
getDual ((forall (x :: k). f x -> Dual (Endo b)) -> t f x -> Dual (Endo b)
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) m.
(FoldableFC t, Monoid m) =>
(forall (x :: k). f x -> m) -> forall (x :: l). t f x -> m
foldMapFC (\f x
e -> Endo b -> Dual (Endo b)
forall a. a -> Dual a
Dual ((b -> b) -> Endo b
forall a. (a -> a) -> Endo a
Endo (\b
r -> b -> f x -> b
forall (x :: k). b -> f x -> b
f b
r f x
e))) t f x
t)) b
z

  -- | Right-associative fold of a structure,
  -- but with strict application of the operator.
  foldrFC' :: forall f b. (forall x. f x -> b -> b) -> (forall x. b -> t f x -> b)
  foldrFC' forall (x :: k). f x -> b -> b
f0 b
z0 t f x
xs = (forall (x :: k). (b -> b) -> f x -> b -> b)
-> (b -> b) -> t f x -> b -> b
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). b -> f x -> b)
-> forall (x :: l). b -> t f x -> b
foldlFC ((f x -> b -> b) -> (b -> b) -> f x -> b -> b
forall t t a b. (t -> t -> a) -> (a -> b) -> t -> t -> b
f' f x -> b -> b
forall (x :: k). f x -> b -> b
f0) b -> b
forall a. a -> a
id t f x
xs b
z0
    where f' :: (t -> t -> a) -> (a -> b) -> t -> t -> b
f' t -> t -> a
f a -> b
k t
x t
z = a -> b
k (a -> b) -> a -> b
forall a b. (a -> b) -> a -> b
$! t -> t -> a
f t
x t
z

  -- | Left-associative fold of a parameterized structure
  -- with a strict accumulator.
  foldlFC' :: forall f b. (forall x. b -> f x -> b) -> (forall x. b -> t f x -> b)
  foldlFC' forall (x :: k). b -> f x -> b
f0 b
z0 t f x
xs = (forall (x :: k). f x -> (b -> b) -> b -> b)
-> (b -> b) -> t f x -> b -> b
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). f x -> b -> b)
-> forall (x :: l). b -> t f x -> b
foldrFC ((b -> f x -> b) -> f x -> (b -> b) -> b -> b
forall t t a b. (t -> t -> a) -> t -> (a -> b) -> t -> b
f' b -> f x -> b
forall (x :: k). b -> f x -> b
f0) b -> b
forall a. a -> a
id t f x
xs b
z0
    where f' :: (t -> t -> a) -> t -> (a -> b) -> t -> b
f' t -> t -> a
f t
x a -> b
k t
z = a -> b
k (a -> b) -> a -> b
forall a b. (a -> b) -> a -> b
$! t -> t -> a
f t
z t
x

  -- | Convert structure to list.
  toListFC :: forall f a. (forall x. f x -> a) -> (forall x. t f x -> [a])
  toListFC forall (x :: k). f x -> a
f t f x
t = (forall b. (a -> b -> b) -> b -> b) -> [a]
forall a. (forall b. (a -> b -> b) -> b -> b) -> [a]
build (\a -> b -> b
c b
n -> (forall (x :: k). f x -> b -> b) -> b -> t f x -> b
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). f x -> b -> b)
-> forall (x :: l). b -> t f x -> b
foldrFC (\f x
e b
v -> a -> b -> b
c (f x -> a
forall (x :: k). f x -> a
f f x
e) b
v) b
n t f x
t)

-- | Monadic fold over the elements of a structure from left to right.
foldlMFC :: (FoldableFC t, Monad m) => (forall x . b -> f x -> m b) -> b -> t f c -> m b
foldlMFC :: (forall (x :: k). b -> f x -> m b) -> b -> t f c -> m b
foldlMFC forall (x :: k). b -> f x -> m b
f b
z0 t f c
xs = (forall (x :: k). f x -> (b -> m b) -> b -> m b)
-> (b -> m b) -> t f c -> b -> m b
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). f x -> b -> b)
-> forall (x :: l). b -> t f x -> b
foldrFC forall (x :: k). f x -> (b -> m b) -> b -> m b
forall (x :: k) b. f x -> (b -> m b) -> b -> m b
f' b -> m b
forall (m :: * -> *) a. Monad m => a -> m a
return t f c
xs b
z0
  where f' :: f x -> (b -> m b) -> b -> m b
f' f x
x b -> m b
k b
z = b -> f x -> m b
forall (x :: k). b -> f x -> m b
f b
z f x
x m b -> (b -> m b) -> m b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= b -> m b
k

-- | Monadic strict fold over the elements of a structure from left to right.
foldlMFC' :: (FoldableFC t, Monad m) => (forall x . b -> f x -> m b) -> b -> t f c -> m b
foldlMFC' :: (forall (x :: k). b -> f x -> m b) -> b -> t f c -> m b
foldlMFC' forall (x :: k). b -> f x -> m b
f b
z0 t f c
xs = b -> m b -> m b
seq b
z0 (m b -> m b) -> m b -> m b
forall a b. (a -> b) -> a -> b
$ (forall (x :: k). f x -> (b -> m b) -> b -> m b)
-> (b -> m b) -> t f c -> b -> m b
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). f x -> b -> b)
-> forall (x :: l). b -> t f x -> b
foldrFC forall (x :: k). f x -> (b -> m b) -> b -> m b
forall (x :: k) b. f x -> (b -> m b) -> b -> m b
f' b -> m b
forall (m :: * -> *) a. Monad m => a -> m a
return t f c
xs b
z0
  where f' :: f x -> (b -> m b) -> b -> m b
f' f x
x b -> m b
k b
z = b -> f x -> m b
forall (x :: k). b -> f x -> m b
f b
z f x
x m b -> (b -> m b) -> m b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \b
r -> b -> m b -> m b
seq b
r (b -> m b
k b
r)

-- | Monadic fold over the elements of a structure from right to left.
foldrMFC :: (FoldableFC t, Monad m) => (forall x . f x -> b -> m b) -> b -> t f c -> m b
foldrMFC :: (forall (x :: k). f x -> b -> m b) -> b -> t f c -> m b
foldrMFC forall (x :: k). f x -> b -> m b
f b
z0 t f c
xs = (forall (x :: k). (b -> m b) -> f x -> b -> m b)
-> (b -> m b) -> t f c -> b -> m b
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). b -> f x -> b)
-> forall (x :: l). b -> t f x -> b
foldlFC forall (x :: k). (b -> m b) -> f x -> b -> m b
forall b (x :: k). (b -> m b) -> f x -> b -> m b
f' b -> m b
forall (m :: * -> *) a. Monad m => a -> m a
return t f c
xs b
z0
  where f' :: (b -> m b) -> f x -> b -> m b
f' b -> m b
k f x
x b
z = f x -> b -> m b
forall (x :: k). f x -> b -> m b
f f x
x b
z m b -> (b -> m b) -> m b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= b -> m b
k

-- | Monadic strict fold over the elements of a structure from right to left.
foldrMFC' :: (FoldableFC t, Monad m) => (forall x . f x -> b -> m b) -> b -> t f c -> m b
foldrMFC' :: (forall (x :: k). f x -> b -> m b) -> b -> t f c -> m b
foldrMFC' forall (x :: k). f x -> b -> m b
f b
z0 t f c
xs = b -> m b -> m b
seq b
z0 ((forall (x :: k). (b -> m b) -> f x -> b -> m b)
-> (b -> m b) -> t f c -> b -> m b
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). b -> f x -> b)
-> forall (x :: l). b -> t f x -> b
foldlFC forall (x :: k). (b -> m b) -> f x -> b -> m b
forall b (x :: k). (b -> m b) -> f x -> b -> m b
f' b -> m b
forall (m :: * -> *) a. Monad m => a -> m a
return t f c
xs b
z0)
  where f' :: (b -> m b) -> f x -> b -> m b
f' b -> m b
k f x
x b
z = f x -> b -> m b
forall (x :: k). f x -> b -> m b
f f x
x b
z m b -> (b -> m b) -> m b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \b
r -> b -> m b -> m b
seq b
r (b -> m b
k b
r)

-- | Return 'True' if all values satisfy predicate.
allFC :: FoldableFC t => (forall x. f x -> Bool) -> (forall x. t f x -> Bool)
allFC :: (forall (x :: k). f x -> Bool) -> forall (x :: l). t f x -> Bool
allFC forall (x :: k). f x -> Bool
p = All -> Bool
getAll (All -> Bool) -> (t f x -> All) -> t f x -> Bool
forall b c a. Coercible b c => (b -> c) -> (a -> b) -> a -> c
#. (forall (x :: k). f x -> All) -> forall (x :: l). t f x -> All
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) m.
(FoldableFC t, Monoid m) =>
(forall (x :: k). f x -> m) -> forall (x :: l). t f x -> m
foldMapFC (Bool -> All
All (Bool -> All) -> (f x -> Bool) -> f x -> All
forall b c a. Coercible b c => (b -> c) -> (a -> b) -> a -> c
#. f x -> Bool
forall (x :: k). f x -> Bool
p)

-- | Return 'True' if any values satisfy predicate.
anyFC :: FoldableFC t => (forall x. f x -> Bool) -> (forall x. t f x -> Bool)
anyFC :: (forall (x :: k). f x -> Bool) -> forall (x :: l). t f x -> Bool
anyFC forall (x :: k). f x -> Bool
p = Any -> Bool
getAny (Any -> Bool) -> (t f x -> Any) -> t f x -> Bool
forall b c a. Coercible b c => (b -> c) -> (a -> b) -> a -> c
#. (forall (x :: k). f x -> Any) -> forall (x :: l). t f x -> Any
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) m.
(FoldableFC t, Monoid m) =>
(forall (x :: k). f x -> m) -> forall (x :: l). t f x -> m
foldMapFC (Bool -> Any
Any (Bool -> Any) -> (f x -> Bool) -> f x -> Any
forall b c a. Coercible b c => (b -> c) -> (a -> b) -> a -> c
#. f x -> Bool
forall (x :: k). f x -> Bool
p)

-- | Return number of elements that we fold over.
lengthFC :: FoldableFC t => t f x -> Int
lengthFC :: t f x -> Int
lengthFC = (forall (x :: k). f x -> Int -> Int) -> Int -> t f x -> Int
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). f x -> b -> b)
-> forall (x :: l). b -> t f x -> b
foldrFC ((Int -> Int) -> f x -> Int -> Int
forall a b. a -> b -> a
const (Int -> Int -> Int
forall a. Num a => a -> a -> a
+Int
1)) Int
0

------------------------------------------------------------------------
-- TraversableF

class (FunctorFC t, FoldableFC t) => TraversableFC (t :: (k -> *) -> l -> *) where
  traverseFC :: forall f g m. Applicative m
             => (forall x. f x -> m (g x))
             -> (forall x. t f x -> m (t g x))

-- | This function may be used as a value for `fmapF` in a `FunctorF`
-- instance.
fmapFCDefault :: TraversableFC t => forall f g. (forall x. f x -> g x) -> (forall x. t f x -> t g x)
fmapFCDefault :: forall (f :: k -> *) (g :: k -> *).
(forall (x :: k). f x -> g x) -> forall (x :: l). t f x -> t g x
fmapFCDefault = \forall (x :: k). f x -> g x
f -> Identity (t g x) -> t g x
forall a. Identity a -> a
runIdentity (Identity (t g x) -> t g x)
-> (t f x -> Identity (t g x)) -> t f x -> t g x
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (forall (x :: k). f x -> Identity (g x))
-> forall (x :: l). t f x -> Identity (t g x)
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) (g :: k -> *)
       (m :: * -> *).
(TraversableFC t, Applicative m) =>
(forall (x :: k). f x -> m (g x))
-> forall (x :: l). t f x -> m (t g x)
traverseFC (g x -> Identity (g x)
forall a. a -> Identity a
Identity (g x -> Identity (g x)) -> (f x -> g x) -> f x -> Identity (g x)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. f x -> g x
forall (x :: k). f x -> g x
f)
{-# INLINE fmapFCDefault #-}

-- | This function may be used as a value for `Data.Foldable.foldMap`
-- in a `Foldable` instance.
foldMapFCDefault :: (TraversableFC t, Monoid m) => (forall x. f x -> m) -> (forall x. t f x -> m)
foldMapFCDefault :: (forall (x :: k). f x -> m) -> forall (x :: l). t f x -> m
foldMapFCDefault = \forall (x :: k). f x -> m
f -> Const m (t Any x) -> m
forall a k (b :: k). Const a b -> a
getConst (Const m (t Any x) -> m)
-> (t f x -> Const m (t Any x)) -> t f x -> m
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (forall (x :: k). f x -> Const m (Any x))
-> forall (x :: l). t f x -> Const m (t Any x)
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) (g :: k -> *)
       (m :: * -> *).
(TraversableFC t, Applicative m) =>
(forall (x :: k). f x -> m (g x))
-> forall (x :: l). t f x -> m (t g x)
traverseFC (m -> Const m (Any x)
forall k a (b :: k). a -> Const a b
Const (m -> Const m (Any x)) -> (f x -> m) -> f x -> Const m (Any x)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. f x -> m
forall (x :: k). f x -> m
f)
{-# INLINE foldMapFCDefault #-}

-- | Map each element of a structure to an action, evaluate
-- these actions from left to right, and ignore the results.
traverseFC_ :: (FoldableFC t, Applicative m) => (forall x. f x -> m a) -> (forall x. t f x -> m ())
traverseFC_ :: (forall (x :: k). f x -> m a) -> forall (x :: l). t f x -> m ()
traverseFC_ forall (x :: k). f x -> m a
f = (forall (x :: k). f x -> m () -> m ()) -> m () -> t f x -> m ()
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) b.
FoldableFC t =>
(forall (x :: k). f x -> b -> b)
-> forall (x :: l). b -> t f x -> b
foldrFC (\f x
e m ()
r -> f x -> m a
forall (x :: k). f x -> m a
f f x
e m a -> m () -> m ()
forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> m ()
r) (() -> m ()
forall (f :: * -> *) a. Applicative f => a -> f a
pure ())
{-# INLINE traverseFC_ #-}

-- | Map each element of a structure to an action, evaluate
-- these actions from left to right, and ignore the results.
forMFC_ :: (FoldableFC t, Applicative m) => t f c -> (forall x. f x -> m a) -> m ()
forMFC_ :: t f c -> (forall (x :: k). f x -> m a) -> m ()
forMFC_ t f c
v forall (x :: k). f x -> m a
f = (forall (x :: k). f x -> m a) -> t f c -> m ()
forall k l (t :: (k -> *) -> l -> *) (m :: * -> *) (f :: k -> *) a.
(FoldableFC t, Applicative m) =>
(forall (x :: k). f x -> m a) -> forall (x :: l). t f x -> m ()
traverseFC_ forall (x :: k). f x -> m a
f t f c
v
{-# INLINE forMFC_ #-}
{-# DEPRECATED forMFC_ "Use forFC_" #-}

-- | Map each element of a structure to an action, evaluate
-- these actions from left to right, and ignore the results.
forFC_ :: (FoldableFC t, Applicative m) => t f c -> (forall x. f x -> m a) -> m ()
forFC_ :: t f c -> (forall (x :: k). f x -> m a) -> m ()
forFC_ t f c
v forall (x :: k). f x -> m a
f = (forall (x :: k). f x -> m a) -> t f c -> m ()
forall k l (t :: (k -> *) -> l -> *) (m :: * -> *) (f :: k -> *) a.
(FoldableFC t, Applicative m) =>
(forall (x :: k). f x -> m a) -> forall (x :: l). t f x -> m ()
traverseFC_ forall (x :: k). f x -> m a
f t f c
v
{-# INLINE forFC_ #-}

-- | Flipped 'traverseFC'
forFC ::
  (TraversableFC t, Applicative m) =>
  t f x -> (forall y. f y -> m (g y)) -> m (t g x)
forFC :: t f x -> (forall (y :: k). f y -> m (g y)) -> m (t g x)
forFC t f x
v forall (y :: k). f y -> m (g y)
f = (forall (y :: k). f y -> m (g y)) -> t f x -> m (t g x)
forall k l (t :: (k -> *) -> l -> *) (f :: k -> *) (g :: k -> *)
       (m :: * -> *).
(TraversableFC t, Applicative m) =>
(forall (x :: k). f x -> m (g x))
-> forall (x :: l). t f x -> m (t g x)
traverseFC forall (y :: k). f y -> m (g y)
f t f x
v
{-# INLINE forFC #-}