3 files changed, 12 insertions, 23 deletions
diff --git a/src/Data/Array/Nested/Convert.hs b/src/Data/Array/Nested/Convert.hs
index 86534f1..408bf8a 100644
--- a/src/Data/Array/Nested/Convert.hs
+++ b/src/Data/Array/Nested/Convert.hs
@@ -18,7 +18,7 @@ module Data.Array.Nested.Convert (
   ixrFromIxS, ixrFromIxX, shrFromShS, shrFromShXAnyShape, shrFromShX,
   listrCast, ixrCast, shrCast,
   -- ** To shaped
-  ixsFromIxR, ixsFromIxR', ixsFromIxX, ixsFromIxX', withShsFromShR, shsFromShX, withShsFromShX, shsFromSSX,
+  ixsFromIxR, ixsFromIxX, ixsFromIxX', withShsFromShR, shsFromShX, withShsFromShX, shsFromSSX,
   ixsCast,
   -- ** To mixed
   ixxFromIxR, ixxFromIxS, shxFromShR, shxFromShS,
@@ -59,7 +59,8 @@ import Data.Array.Nested.Types
 
 -- TODO: change all those unsafeCoerces into coerces by defining shaped
 -- and ranekd index types as newtypes of the mixed index type
--- and similarly for the sized lists
+-- and similarly for the sized lists or, preferably, by defining
+-- all as newtypes over [], exploiting fusion and getting free toList.
 ixrFromIxS :: IxS sh i -> IxR (Rank sh) i
 ixrFromIxS = unsafeCoerce
 
@@ -82,25 +83,13 @@ shrFromShX = coerce
 
 -- * To shaped
 
--- TODO: remove the ShS now that no KnownNats is inside IxS.
-ixsFromIxR :: ShS sh -> IxR (Rank sh) i -> IxS sh i
-ixsFromIxR _ = unsafeCoerce
-
--- TODO: if possible, remove the ShS now that no KnownNats is inside IxS.
--- | Performs a runtime check that @n@ matches @Rank sh@. Equivalent to the
--- following, but more efficient:
---
--- > ixsFromIxR' sh idx = ixsFromIxR sh (ixrCast (shsRank sh) idx)
-ixsFromIxR' :: ShS sh -> IxR n i -> IxS sh i
-ixsFromIxR' ZSS ZIR = ZIS
-ixsFromIxR' (_ :$$ sh) (n :.: idx) = n :.$ ixsFromIxR' sh idx
-ixsFromIxR' _ _ = error "ixsFromIxR': index rank does not match shape rank"
+ixsFromIxR :: IxR (Rank sh) i -> IxS sh i
+ixsFromIxR = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
 
 -- ixsFromIxX re-exported
 
--- TODO: if possible, remove the ShS now that no KnownNats is inside IxS.
 -- | Performs a runtime check that @Rank sh'@ match @Rank sh@. Equivalent to
--- the following, but more efficient:
+-- the following, but less verbose:
 --
 -- > ixsFromIxX' sh idx = ixsFromIxX sh (ixxCast (shxFromShS sh) idx)
 ixsFromIxX' :: ShS sh -> IxX sh' i -> IxS sh i
diff --git a/src/Data/Array/Nested/Ranked/Shape.hs b/src/Data/Array/Nested/Ranked/Shape.hs
index 2415e26..6d47ade 100644
--- a/src/Data/Array/Nested/Ranked/Shape.hs
+++ b/src/Data/Array/Nested/Ranked/Shape.hs
@@ -293,7 +293,7 @@ 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
+ixxFromIxR = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
 
 {-# INLINEABLE ixrFromLinear #-}
 ixrFromLinear :: forall i m. Num i => IShR m -> Int -> IxR m i
@@ -302,7 +302,7 @@ ixrFromLinear (ShR sh) i
   = ixrFromIxX $ ixxFromLinear sh i
 
 ixrFromIxX :: IxX sh i -> IxR (Rank sh) i
-ixrFromIxX = unsafeCoerce
+ixrFromIxX = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
 
 shrEnum :: IShR n -> [IIxR n]
 shrEnum = shrEnum'
@@ -312,7 +312,7 @@ 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
 
 -- * Ranked shapes
 
diff --git a/src/Data/Array/Nested/Shaped/Shape.hs b/src/Data/Array/Nested/Shaped/Shape.hs
index 8cd937c..c5e3202 100644
--- a/src/Data/Array/Nested/Shaped/Shape.hs
+++ b/src/Data/Array/Nested/Shaped/Shape.hs
@@ -275,14 +275,14 @@ 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
+ixxFromIxS = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
 
 {-# 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
+ixsFromIxX = unsafeCoerce  -- TODO: switch to coerce once newtypes overhauled
 
 shsEnum :: ShS sh -> [IIxS sh]
 shsEnum = shsEnum'
@@ -290,7 +290,7 @@ 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
 
 -- * Shaped shapes