1 files changed, 58 insertions, 49 deletions
diff --git a/src/Data/Array/Nested/Convert.hs b/src/Data/Array/Nested/Convert.hs
index dd26f16..73055db 100644
--- a/src/Data/Array/Nested/Convert.hs
+++ b/src/Data/Array/Nested/Convert.hs
@@ -7,10 +7,14 @@
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeOperators #-}
 module Data.Array.Nested.Convert (
+  -- * Shape/index/list casting functions
+  ixrFromIxS, shrFromShS,
+
+  -- * Array conversions
   castCastable,
   Castable(..),
 
-  -- * Special cases
+  -- * Special cases of array conversions
   --
   -- | These functions can all be implemented using 'castCastable' in some way,
   -- but some have fewer constraints.
@@ -18,8 +22,6 @@ module Data.Array.Nested.Convert (
   stoMixed, scastToMixed, stoRanked,
   mcast, mcastToShaped, mtoRanked,
 
-  -- * Additional index/shape casting functions
-  ixrFromIxS, shrFromShS,
 ) where
 
 import Control.Category
@@ -35,52 +37,7 @@ import Data.Array.Nested.Shaped.Base
 import Data.Array.Nested.Shaped.Shape
 import Data.Array.Nested.Types
 
-
-mcast :: forall sh1 sh2 a. (Rank sh1 ~ Rank sh2, Elt a)
-      => StaticShX sh2 -> Mixed sh1 a -> Mixed sh2 a
-mcast ssh2 arr
-  | Refl <- lemAppNil @sh1
-  , Refl <- lemAppNil @sh2
-  = mcastPartial (ssxFromShX (mshape arr)) ssh2 (Proxy @'[]) arr
-
-mtoRanked :: forall sh a. Elt a => Mixed sh a -> Ranked (Rank sh) a
-mtoRanked = castCastable (CastXR CastId)
-
-rtoMixed :: forall n a. Ranked n a -> Mixed (Replicate n Nothing) a
-rtoMixed (Ranked arr) = arr
-
--- | A more weakly-typed version of 'rtoMixed' that does a runtime shape
--- compatibility check.
-rcastToMixed :: (Rank sh ~ n, Elt a) => StaticShX sh -> Ranked n a -> Mixed sh a
-rcastToMixed sshx rarr@(Ranked arr)
-  | Refl <- lemRankReplicate (rrank rarr)
-  = mcast sshx arr
-
-mcastToShaped :: forall sh sh' a. (Elt a, Rank sh ~ Rank sh')
-              => ShS sh' -> Mixed sh a -> Shaped sh' a
-mcastToShaped targetsh = castCastable (CastXS' targetsh CastId)
-
-stoMixed :: forall sh a. Shaped sh a -> Mixed (MapJust sh) a
-stoMixed (Shaped arr) = arr
-
--- | A more weakly-typed version of 'stoMixed' that does a runtime shape
--- compatibility check.
-scastToMixed :: forall sh sh' a. (Elt a, Rank sh ~ Rank sh')
-             => StaticShX sh' -> Shaped sh a -> Mixed sh' a
-scastToMixed sshx sarr@(Shaped arr)
-  | Refl <- lemRankMapJust (sshape sarr)
-  = mcast sshx arr
-
-stoRanked :: Elt a => Shaped sh a -> Ranked (Rank sh) a
-stoRanked sarr@(Shaped arr)
-  | Refl <- lemRankMapJust (sshape sarr)
-  = mtoRanked arr
-
-rcastToShaped :: Elt a => Ranked (Rank sh) a -> ShS sh -> Shaped sh a
-rcastToShaped (Ranked arr) targetsh
-  | Refl <- lemRankReplicate (shxRank (shxFromShS targetsh))
-  , Refl <- lemRankMapJust targetsh
-  = mcastToShaped targetsh arr
+-- * Shape/index/list casting functions
 
 ixrFromIxS :: IxS sh i -> IxR (Rank sh) i
 ixrFromIxS ZIS = ZIR
@@ -97,6 +54,9 @@ shrFromShS :: ShS sh -> IShR (Rank sh)
 shrFromShS ZSS = ZSR
 shrFromShS (n :$$ sh) = fromSNat' n :$: shrFromShS sh
 
+
+-- * Array conversions
+
 -- | The constructors that perform runtime shape checking are marked with a
 -- @'@: 'CastXS'' and 'CastXX''. For the other constructors, the types ensure
 -- that the shapes are already compatible. To convert between 'Ranked' and
@@ -169,3 +129,52 @@ castCastable = \c x -> munScalar (go c (mscalar x))
                             => Proxy esh -> Proxy sh -> Proxy sh'
                             -> Rank (esh ++ sh) :~: Rank (esh ++ MapJust sh')
     lemRankAppRankEqMapJust _ _ _ = unsafeCoerceRefl
+
+
+-- * Special cases of array conversions
+
+mcast :: forall sh1 sh2 a. (Rank sh1 ~ Rank sh2, Elt a)
+      => StaticShX sh2 -> Mixed sh1 a -> Mixed sh2 a
+mcast ssh2 arr
+  | Refl <- lemAppNil @sh1
+  , Refl <- lemAppNil @sh2
+  = mcastPartial (ssxFromShX (mshape arr)) ssh2 (Proxy @'[]) arr
+
+mtoRanked :: forall sh a. Elt a => Mixed sh a -> Ranked (Rank sh) a
+mtoRanked = castCastable (CastXR CastId)
+
+rtoMixed :: forall n a. Ranked n a -> Mixed (Replicate n Nothing) a
+rtoMixed (Ranked arr) = arr
+
+-- | A more weakly-typed version of 'rtoMixed' that does a runtime shape
+-- compatibility check.
+rcastToMixed :: (Rank sh ~ n, Elt a) => StaticShX sh -> Ranked n a -> Mixed sh a
+rcastToMixed sshx rarr@(Ranked arr)
+  | Refl <- lemRankReplicate (rrank rarr)
+  = mcast sshx arr
+
+mcastToShaped :: forall sh sh' a. (Elt a, Rank sh ~ Rank sh')
+              => ShS sh' -> Mixed sh a -> Shaped sh' a
+mcastToShaped targetsh = castCastable (CastXS' targetsh CastId)
+
+stoMixed :: forall sh a. Shaped sh a -> Mixed (MapJust sh) a
+stoMixed (Shaped arr) = arr
+
+-- | A more weakly-typed version of 'stoMixed' that does a runtime shape
+-- compatibility check.
+scastToMixed :: forall sh sh' a. (Elt a, Rank sh ~ Rank sh')
+             => StaticShX sh' -> Shaped sh a -> Mixed sh' a
+scastToMixed sshx sarr@(Shaped arr)
+  | Refl <- lemRankMapJust (sshape sarr)
+  = mcast sshx arr
+
+stoRanked :: Elt a => Shaped sh a -> Ranked (Rank sh) a
+stoRanked sarr@(Shaped arr)
+  | Refl <- lemRankMapJust (sshape sarr)
+  = mtoRanked arr
+
+rcastToShaped :: Elt a => Ranked (Rank sh) a -> ShS sh -> Shaped sh a
+rcastToShaped (Ranked arr) targetsh
+  | Refl <- lemRankReplicate (shxRank (shxFromShS targetsh))
+  , Refl <- lemRankMapJust targetsh
+  = mcastToShaped targetsh arr