From 7501414935c8f24d5e132405dd897d46e240b692 Mon Sep 17 00:00:00 2001
From: Tom Smeding <tom@tomsmeding.com>
Date: Mon, 13 May 2024 19:45:35 +0200
Subject: Annotate all lists of primitive element types in the source

---
 src/Data/Array/Nested/Internal.hs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/Data/Array/Nested/Internal.hs b/src/Data/Array/Nested/Internal.hs
index 6f22e59..4577967 100644
--- a/src/Data/Array/Nested/Internal.hs
+++ b/src/Data/Array/Nested/Internal.hs
@@ -79,6 +79,16 @@ import Data.INat
 --   -> no, because mlift and also any kind of internals probing from outsiders
 
 
+-- Primitive element types
+-- =======================
+--
+-- There are a few primitive element types; arrays containing elements of such
+-- type are a newtype over an XArray, which it itself a newtype over a Vector.
+-- Unfortunately, the setup of the library requires us to list these primitive
+-- element types multiple times; to aid in extending the list, all these lists
+-- have been marked with [PRIMITIVE ELEMENT TYPES LIST].
+
+
 type family Replicate n a where
   Replicate Z a = '[]
   Replicate (S n) a = a : Replicate n a
@@ -141,6 +151,7 @@ data family Mixed sh a
 newtype instance Mixed sh (Primitive a) = M_Primitive (XArray sh a)
   deriving (Show)
 
+-- [PRIMITIVE ELEMENT TYPES LIST]
 newtype instance Mixed sh Int = M_Int (XArray sh Int)
   deriving (Show)
 newtype instance Mixed sh Double = M_Double (XArray sh Double)
@@ -164,6 +175,7 @@ data family MixedVecs s sh a
 
 newtype instance MixedVecs s sh (Primitive a) = MV_Primitive (VS.MVector s a)
 
+-- [PRIMITIVE ELEMENT TYPES LIST]
 newtype instance MixedVecs s sh Int = MV_Int (VS.MVector s Int)
 newtype instance MixedVecs s sh Double = MV_Double (VS.MVector s Double)
 newtype instance MixedVecs s sh () = MV_Nil (VS.MVector s ())  -- no content, MVector optimises this
@@ -178,6 +190,7 @@ data instance MixedVecs s sh1 (Mixed sh2 a) = MV_Nest !(IIxX sh2) !(MixedVecs s
 -- | Tree giving the shape of every array component.
 type family ShapeTree a where
   ShapeTree (Primitive _) = ()
+  -- [PRIMITIVE ELEMENT TYPES LIST]
   ShapeTree Int = ()
   ShapeTree Double = ()
   ShapeTree () = ()
@@ -306,6 +319,7 @@ instance Storable a => Elt (Primitive a) where
 
   mvecsFreeze sh (MV_Primitive v) = M_Primitive . X.fromVector sh <$> VS.freeze v
 
+-- [PRIMITIVE ELEMENT TYPES LIST]
 deriving via Primitive Int instance Elt Int
 deriving via Primitive Double instance Elt Double
 deriving via Primitive () instance Elt ()
@@ -548,6 +562,7 @@ instance (KnownShapeX sh, Storable a, Num a) => Num (Mixed sh (Primitive a)) whe
       Nothing -> error "Data.Array.Nested.fromIntegral: \
                        \Unknown components in shape, use explicit mconstant"
 
+-- [PRIMITIVE ELEMENT TYPES LIST] (really, a partial list of just the numeric types)
 deriving via Mixed sh (Primitive Int) instance KnownShapeX sh => Num (Mixed sh Int)
 deriving via Mixed sh (Primitive Double) instance KnownShapeX sh => Num (Mixed sh Double)
 
@@ -850,6 +865,7 @@ instance (KnownINat n, Storable a, Num a) => Num (Ranked n (Primitive a)) where
                     SS _ -> error "Data.Array.Nested.fromIntegral(Ranked): \
                                   \Rank non-zero, use explicit mconstant"
 
+-- [PRIMITIVE ELEMENT TYPES LIST] (really, a partial list of just the numeric types)
 deriving via Ranked n (Primitive Int) instance KnownINat n => Num (Ranked n Int)
 deriving via Ranked n (Primitive Double) instance KnownINat n => Num (Ranked n Double)
 
@@ -1067,6 +1083,7 @@ instance (KnownShape sh, Storable a, Num a) => Num (Shaped sh (Primitive a)) whe
   signum = arithPromoteShaped signum
   fromInteger n = sconstantP (fromInteger n)
 
+-- [PRIMITIVE ELEMENT TYPES LIST] (really, a partial list of just the numeric types)
 deriving via Shaped sh (Primitive Int) instance KnownShape sh => Num (Shaped sh Int)
 deriving via Shaped sh (Primitive Double) instance KnownShape sh => Num (Shaped sh Double)
 
-- 
cgit v1.2.3-70-g09d2