Implement ranked shape conversions as newtype coerces

1 files changed, 2 insertions, 15 deletions

diff --git a/src/Data/Array/Nested/Ranked/Base.hs b/src/Data/Array/Nested/Ranked/Base.hs
index d744c0a..9d88815 100644
--- a/src/Data/Array/Nested/Ranked/Base.hs
+++ b/src/Data/Array/Nested/Ranked/Base.hs
@@ -26,7 +26,6 @@ import Data.Coerce (coerce)
 import Data.Kind (Type)
 import Data.List.NonEmpty (NonEmpty)
 import Data.Proxy
-import Data.Type.Equality
 import Foreign.Storable (Storable)
 import GHC.Float qualified (expm1, log1mexp, log1p, log1pexp)
 import GHC.Generics (Generic)
@@ -138,7 +137,7 @@ instance Elt a => Elt (Ranked n a) where
 
   type ShapeTree (Ranked n a) = (IShR n, ShapeTree a)
 
-  mshapeTree (Ranked arr) = first shrFromShX2 (mshapeTree arr)
+  mshapeTree (Ranked arr) = first coerce (mshapeTree arr)
 
   mshapeTreeEq _ (sh1, t1) (sh2, t2) = sh1 == sh2 && mshapeTreeEq (Proxy @a) t1 t2
 
@@ -262,19 +261,7 @@ ratan2Array = liftRanked2 matan2Array
 
 
 rshape :: Elt a => Ranked n a -> IShR n
-rshape (Ranked arr) = shrFromShX2 (mshape arr)
+rshape (Ranked arr) = coerce (mshape arr)
 
 rrank :: Elt a => Ranked n a -> SNat n
 rrank = shrRank . rshape
-
--- Needed already here, but re-exported in Data.Array.Nested.Convert.
-shrFromShX :: forall sh. IShX sh -> IShR (Rank sh)
-shrFromShX ZSX = ZSR
-shrFromShX (n :$% idx) = fromSMayNat' n :$: shrFromShX idx
-
--- Needed already here, but re-exported in Data.Array.Nested.Convert.
--- | Convenience wrapper around 'shrFromShX' that applies 'lemRankReplicate'.
-shrFromShX2 :: forall n. IShX (Replicate n Nothing) -> IShR n
-shrFromShX2 sh
-  | Refl <- lemRankReplicate (Proxy @n)
-  = shrFromShX sh