Remove almost all unsafeCoerce

3 files changed, 11 insertions, 18 deletions

diff --git a/src/Data/Array/Nested/Convert.hs b/src/Data/Array/Nested/Convert.hs
index d6bdc6a..155a1a7 100644
--- a/src/Data/Array/Nested/Convert.hs
+++ b/src/Data/Array/Nested/Convert.hs
@@ -57,10 +57,7 @@ import Data.Array.Nested.Types
 
 -- * To ranked
 
--- TODO: change all those unsafeCoerces into coerces by defining shaped
--- and ranked index types as newtypes of the mixed index type
--- and similarly for the sized lists or, preferably, by defining
--- all as newtypes over [], exploiting fusion and getting free toList.
+-- This unsafeCoerce, exceptionally, can't be eliminated using newtype coercions.
 ixrFromIxS :: IxS sh i -> IxR (Rank sh) i
 ixrFromIxS = unsafeCoerce
 
@@ -83,8 +80,9 @@ shrFromShX = coerce
 
 -- * To shaped
 
+-- This unsafeCoerce, exceptionally, can't be eliminated using newtype coercions.
 ixsFromIxR :: IxR (Rank sh) i -> IxS sh i
-ixsFromIxR = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
+ixsFromIxR = unsafeCoerce
 
 -- ixsFromIxX re-exported
 
diff --git a/src/Data/Array/Nested/Ranked/Shape.hs b/src/Data/Array/Nested/Ranked/Shape.hs
index b0fb30d..6d94c8d 100644
--- a/src/Data/Array/Nested/Ranked/Shape.hs
+++ b/src/Data/Array/Nested/Ranked/Shape.hs
@@ -38,7 +38,6 @@ import GHC.IsList (IsList)
 import GHC.IsList qualified as IsList
 import GHC.TypeLits
 import GHC.TypeNats qualified as TN
-import Unsafe.Coerce (unsafeCoerce)
 
 import Data.Array.Nested.Lemmas
 import Data.Array.Nested.Mixed.Shape
@@ -291,7 +290,7 @@ ixrToLinear :: Num i => IShR m -> IxR m i -> i
 ixrToLinear (ShR sh) ix = ixxToLinear sh (ixxFromIxR ix)
 
 ixxFromIxR :: IxR n i -> IxX (Replicate n Nothing) i
-ixxFromIxR = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
+ixxFromIxR = coerce
 
 {-# INLINEABLE ixrFromLinear #-}
 ixrFromLinear :: forall i m. Num i => IShR m -> Int -> IxR m i
@@ -299,8 +298,8 @@ ixrFromLinear (ShR sh) i
   | Refl <- lemRankReplicate (Proxy @m)
   = ixrFromIxX $ ixxFromLinear sh i
 
-ixrFromIxX :: IxX sh i -> IxR (Rank sh) i
-ixrFromIxX = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
+ixrFromIxX :: IxX (Replicate n Nothing) i -> IxR n i
+ixrFromIxX = coerce
 
 shrEnum :: IShR n -> [IIxR n]
 shrEnum = shrEnum'
@@ -309,8 +308,7 @@ shrEnum = shrEnum'
 shrEnum' :: forall i n. Num i => IShR n -> [IxR n i]
 shrEnum' (ShR sh)
   | Refl <- lemRankReplicate (Proxy @n)
-  = (unsafeCoerce :: [IxX (Replicate n Nothing) i] -> [IxR n i]) $ shxEnum' sh
-      -- TODO: switch to coerce once newtypes overhauled
+  = (coerce :: [IxX (Replicate n Nothing) i] -> [IxR n i]) $ shxEnum' sh
 
 -- * Ranked shapes
 
diff --git a/src/Data/Array/Nested/Shaped/Shape.hs b/src/Data/Array/Nested/Shaped/Shape.hs
index 97d1559..c39d482 100644
--- a/src/Data/Array/Nested/Shaped/Shape.hs
+++ b/src/Data/Array/Nested/Shaped/Shape.hs
@@ -36,7 +36,6 @@ import GHC.Exts (build, withDict)
 import GHC.IsList (IsList)
 import GHC.IsList qualified as IsList
 import GHC.TypeLits
-import Unsafe.Coerce (unsafeCoerce)
 
 import Data.Array.Nested.Mixed.Shape
 import Data.Array.Nested.Permutation
@@ -267,22 +266,21 @@ ixsToLinear :: Num i => ShS sh -> IxS sh i -> i
 ixsToLinear (ShS sh) ix = ixxToLinear sh (ixxFromIxS ix)
 
 ixxFromIxS :: IxS sh i -> IxX (MapJust sh) i
-ixxFromIxS = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
+ixxFromIxS = coerce
 
 {-# INLINEABLE ixsFromLinear #-}
 ixsFromLinear :: Num i => ShS sh -> Int -> IxS sh i
 ixsFromLinear (ShS sh) i = ixsFromIxX $ ixxFromLinear sh i
 
 ixsFromIxX :: IxX (MapJust sh) i -> IxS sh i
-ixsFromIxX = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
+ixsFromIxX = coerce
 
 shsEnum :: ShS sh -> [IIxS sh]
 shsEnum = shsEnum'
 
 {-# INLINABLE shsEnum' #-}  -- ensure this can be specialised at use site
 shsEnum' :: Num i => ShS sh -> [IxS sh i]
-shsEnum' (ShS sh) = (unsafeCoerce :: [IxX (MapJust sh) i] -> [IxS sh i]) $ shxEnum' sh
-                      -- TODO: switch to coerce once newtypes overhauled
+shsEnum' (ShS sh) = (coerce :: [IxX (MapJust sh) i] -> [IxS sh i]) $ shxEnum' sh
 
 -- * Shaped shapes
 
@@ -346,8 +344,7 @@ shsLength (ShS shx) = shxLength shx
 
 shsRank :: forall sh. ShS sh -> SNat (Rank sh)
 shsRank (ShS shx) =
-  gcastWith (unsafeCoerceRefl
-             :: Rank (MapJust sh) :~: Rank sh) $
+  gcastWith (unsafeCoerceRefl :: Rank (MapJust sh) :~: Rank sh) $
   shxRank shx
 
 shsSize :: ShS sh -> Int