Add comments showing CPS and store lens idea

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>

src/Lets/OpticPolyLens.hs

@@ -64,6 +64,24 @@ data Lens s t a b =
   Lens
     (forall f. Functor f => (a -> f b) -> s -> f t)
 
+-- Lens s t a b
+
+-- Lens u w s t
+--   (s -> f t) -> w -> f w
+
+-- Lens u w s t . Lens s t a b
+
+-- p :: (->)
+-- p a b
+
+-- f :: s -> a
+-- fcps :: forall r . (a -> r) -> s -> r
+-- f ~ fcps id
+-- fcps = \c -> c . f
+--              (a -> r) . s -> a
+-- forall r . (a -> f r) -> s -> f r
+-- forall f . Functor f => (a -> f b) -> s -> f t
+
 -- Const :: forall b . a -> Const a b
 get ::
   Lens s t a b

src/Lets/StoreLens.hs

@@ -100,6 +100,17 @@ extractS = \(Store sToa s) -> sToa s
 
 ----
 
+-- data Lens a b =
+--   Lens
+--     (a -> b -> a)
+--     (a -> b)
+-- data Store s a = Store (s -> a) s
+
+-- a -> Store b a
+-- a -> Store (b -> a) b
+-- Drop the Store wrapper
+-- a -> b -> a
+-- a -> b
 data Lens a b =
   Lens
     (a -> Store b a)