Make equal-rank-coercibility part of the interface of ListXmove-Rank

1 files changed, 4 insertions, 8 deletions

diff --git a/src/Data/Array/Nested/Mixed/Shape.hs b/src/Data/Array/Nested/Mixed/Shape.hs
index a5e3ced..c678c17 100644
--- a/src/Data/Array/Nested/Mixed/Shape.hs
+++ b/src/Data/Array/Nested/Mixed/Shape.hs
@@ -24,7 +24,10 @@
 {-# LANGUAGE ViewPatterns #-}
 {-# OPTIONS_GHC -fplugin GHC.TypeLits.Normalise #-}
 {-# OPTIONS_GHC -fplugin GHC.TypeLits.KnownNat.Solver #-}
-module Data.Array.Nested.Mixed.Shape where
+module Data.Array.Nested.Mixed.Shape (
+  module Data.Array.Nested.Mixed.Shape,
+  Rank,
+) where
 
 import Control.DeepSeq (NFData(..))
 import Control.Exception (assert)
@@ -47,13 +50,6 @@ import Data.Array.Nested.Mixed.ListX
 import Data.Array.Nested.Types
 
 
--- | The length of a type-level list. If the argument is a shape, then the
--- result is the rank of that shape.
-type family Rank sh where
-  Rank '[] = 0
-  Rank (_ : sh) = Rank sh + 1
-
-
 -- * Mixed lists
 
 {-# INLINE listxFromList #-}