Rename type variables of optics according to s t a b scheme

Author: Topsii

src/Control/Foldl.hs

@@ -1350,8 +1350,8 @@ dropM n (FoldM step begin done) = FoldM step' begin' done'
 
     Any lens, traversal, or prism will type-check as a `Handler`
 -}
-type Handler a b =
-    forall x . (b -> Const (Dual (Endo x)) b) -> a -> Const (Dual (Endo x)) a
+type Handler s a =
+    forall x . (a -> Const (Dual (Endo x)) a) -> s -> Const (Dual (Endo x)) s
 
 {-| @(handles t folder)@ transforms the input of a `Fold` using a lens,
     traversal, or prism:
@@ -1381,7 +1381,7 @@ type Handler a b =
 >
 > handles t (f <*> x) = handles t f <*> handles t x
 -}
-handles :: Handler a b -> Fold b r -> Fold a r
+handles :: Handler s a -> Fold a r -> Fold s r
 handles k (Fold step begin done) = Fold step' begin done
   where
     step' = flip (appEndo . getDual . getConst . k (Const . Dual . Endo . flip step))
@@ -1402,7 +1402,7 @@ handles k (Fold step begin done) = Fold step' begin done
 > Foldl.foldOver folded == Foldl.fold
 
 -}
-foldOver :: Handler s a -> Fold a b -> s -> b
+foldOver :: Handler s a -> Fold a r -> s -> r
 foldOver l (Fold step begin done) =
   done . flip appEndo begin . getDual . getConst . l (Const . Dual . Endo . flip step)
 {-# INLINABLE foldOver #-}
@@ -1432,8 +1432,8 @@ instance Monad m => Monoid (EndoM m a) where
 
     Any lens, traversal, or prism will type-check as a `HandlerM`
 -}
-type HandlerM m a b =
-    forall x . (b -> Const (Dual (EndoM m x)) b) -> a -> Const (Dual (EndoM m x)) a
+type HandlerM m s a =
+    forall x . (a -> Const (Dual (EndoM m x)) a) -> s -> Const (Dual (EndoM m x)) s
 
 {-| @(handlesM t folder)@ transforms the input of a `FoldM` using a lens,
     traversal, or prism:
@@ -1453,7 +1453,7 @@ type HandlerM m a b =
 >
 > handlesM t (f <*> x) = handlesM t f <*> handlesM t x
 -}
-handlesM :: HandlerM m a b -> FoldM m b r -> FoldM m a r
+handlesM :: HandlerM m s a -> FoldM m a r -> FoldM m s r
 handlesM k (FoldM step begin done) = FoldM step' begin done
   where
     step' = flip (appEndoM . getDual . getConst . k (Const . Dual . EndoM . flip step))
@@ -1466,7 +1466,7 @@ handlesM k (FoldM step begin done) = FoldM step' begin done
 > Foldl.foldOverM folded == Foldl.foldM
 
 -}
-foldOverM :: Monad m => HandlerM m s a -> FoldM m a b -> s -> m b
+foldOverM :: Monad m => HandlerM m s a -> FoldM m a r -> s -> m r
 foldOverM l (FoldM step begin done) s = do
   b <- begin
   r <- (flip appEndoM b . getDual . getConst . l (Const . Dual . EndoM . flip step)) s

src/Control/Foldl/NonEmpty.hs

@@ -741,8 +741,8 @@ instance Semigroup (FromMaybe a) where
     This is compatible with van Laarhoven optics as defined in the lens package.
     Any Lens, Fold1 or Traversal1 will type-check as a `Handler1`.
 -}
-type Handler1 a b =
-    forall x. (b -> Const (Dual (FromMaybe x)) b) -> a -> Const (Dual (FromMaybe x)) a
+type Handler1 s a =
+    forall x. (a -> Const (Dual (FromMaybe x)) a) -> s -> Const (Dual (FromMaybe x)) s
 
 {-| @(handles t folder)@ transforms the input of a `Fold1` using a Lens,
     Traversal1, or Fold1 optic:
@@ -765,13 +765,13 @@ type Handler1 a b =
 >
 > handles t (f <*> x) = handles t f <*> handles t x
 -}
-handles :: forall a b r. Handler1 a b -> Fold1 b r -> Fold1 a r
+handles :: forall s a r. Handler1 s a -> Fold1 a r -> Fold1 s r
 handles k (Fold1_ begin step done) = Fold1_ begin' step' done
   where
-    begin' = stepAfromMaybe Nothing
-    step' x = stepAfromMaybe (Just $! x)
-    stepAfromMaybe = flip (appFromMaybe . getDual . getConst . k (Const . Dual . FromMaybe . flip stepBfromMaybe))
-    stepBfromMaybe = maybe begin step
+    begin' = stepSfromMaybe Nothing
+    step' x = stepSfromMaybe (Just $! x)
+    stepSfromMaybe = flip (appFromMaybe . getDual . getConst . k (Const . Dual . FromMaybe . flip stepAfromMaybe))
+    stepAfromMaybe = maybe begin step
 {-# INLINABLE handles #-}
 
 {- | @(foldOver f folder xs)@ folds all values from a Lens, Traversal1 or Fold1 optic with the given folder
@@ -786,7 +786,7 @@ handles k (Fold1_ begin step done) = Fold1_ begin' step' done
 > Foldl1.foldOver folded1 == Foldl1.fold1
 
 -}
-foldOver :: Handler1 s a -> Fold1 a b -> s -> b
+foldOver :: Handler1 s a -> Fold1 a r -> s -> r
 foldOver l (Fold1_ begin step done) =
     done . stepSfromMaybe Nothing
   where
@@ -809,8 +809,8 @@ instance Monad m => Semigroup (FromMaybeM m a) where
     This is compatible with van Laarhoven optics as defined in the lens package.
     Any Lens, Fold1 or Traversal1 will type-check as a `HandlerM1`
 -}
-type HandlerM1 m a b =
-    forall x . (b -> Const (Dual (FromMaybeM m x)) b) -> a -> Const (Dual (FromMaybeM m x)) a
+type HandlerM1 m s a =
+    forall x . (a -> Const (Dual (FromMaybeM m x)) a) -> s -> Const (Dual (FromMaybeM m x)) s
 
 {-| @(handlesM t folder)@ transforms the input of a `FoldM1` using a Lens,
     Traversal1 or Fold1 optic:
@@ -829,13 +829,13 @@ type HandlerM1 m a b =
 >
 > handlesM t (f <*> x) = handlesM t f <*> handlesM t x
 -}
-handlesM :: Monad m => HandlerM1 m a b -> FoldM1 m b r -> FoldM1 m a r
+handlesM :: Monad m => HandlerM1 m s a -> FoldM1 m a r -> FoldM1 m s r
 handlesM k (FoldM1_ begin step done) = FoldM1_ begin' step' done
   where
-    begin' = stepMaybeA Nothing
-    step' b = stepMaybeA (Just $! b)
-    stepMaybeA = flip (appFromMaybeM . getDual . getConst . k (Const . Dual . FromMaybeM . flip stepMaybeB))
-    stepMaybeB = maybe begin step
+    begin' = stepMaybeS Nothing
+    step' b = stepMaybeS (Just $! b)
+    stepMaybeS = flip (appFromMaybeM . getDual . getConst . k (Const . Dual . FromMaybeM . flip stepMaybeA))
+    stepMaybeA = maybe begin step
 {-# INLINABLE handlesM #-}
 
 {- | @(foldOverM f folder xs)@ folds all values from a Lens, Traversal1 or
@@ -846,8 +846,8 @@ handlesM k (FoldM1_ begin step done) = FoldM1_ begin' step' done
 > Foldl1.foldOverM folded1 == Foldl1.foldM1
 
 -}
-foldOverM :: Monad m => HandlerM1 m s a -> FoldM1 m a b -> s -> m b
-foldOverM l (FoldM1_ (begin :: a -> m x) (step :: x -> a -> m x) (done :: x -> m b)) s = do
+foldOverM :: Monad m => HandlerM1 m s a -> FoldM1 m a r -> s -> m r
+foldOverM l (FoldM1_ begin step done) s = do
     r <- stepMaybeS Nothing s
     done r
   where