From 21e52b349aaf0978f0ce5925fef6e53e0c9436f9 Mon Sep 17 00:00:00 2001
From: Mikolaj Konarski <mikolaj.konarski@funktory.com>
Date: Thu, 9 Apr 2026 22:58:39 +0200
Subject: Get rid of most ListX operations

---
 src/Data/Array/Nested/Permutation.hs | 39 +++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

(limited to 'src/Data/Array/Nested/Permutation.hs')

diff --git a/src/Data/Array/Nested/Permutation.hs b/src/Data/Array/Nested/Permutation.hs
index ee79ecf..19d81f0 100644
--- a/src/Data/Array/Nested/Permutation.hs
+++ b/src/Data/Array/Nested/Permutation.hs
@@ -31,7 +31,6 @@ import GHC.TypeNats qualified as TN
 
 import Data.Array.Nested.Mixed.Shape
 import Data.Array.Nested.Types
-import Data.Array.Nested.Mixed.ListX
 
 
 -- * Permutations
@@ -222,31 +221,29 @@ ssxPermutePrefix :: Perm is -> StaticShX sh -> StaticShX (PermutePrefix is sh)
 ssxPermutePrefix = coerce (shxPermutePrefix @())
 
 
-listxTakeLenPerm :: forall i is sh. Perm is -> ListX sh i -> ListX (TakeLen is sh) i
-listxTakeLenPerm PNil _ = ZX
-listxTakeLenPerm (_ `PCons` is) (n ::% sh) = n ::% listxTakeLenPerm is sh
-listxTakeLenPerm (_ `PCons` _) ZX = error "Permutation longer than shape"
+ixxTakeLenPerm :: forall i is sh. Perm is -> IxX sh i -> IxX (TakeLen is sh) i
+ixxTakeLenPerm PNil _ = ZIX
+ixxTakeLenPerm (_ `PCons` is) (n :.% sh) = n :.% ixxTakeLenPerm is sh
+ixxTakeLenPerm (_ `PCons` _) ZIX = error "Permutation longer than shape"
 
-listxDropLenPerm :: forall i is sh. Perm is -> ListX sh i -> ListX (DropLen is sh) i
-listxDropLenPerm PNil sh = sh
-listxDropLenPerm (_ `PCons` is) (_ ::% sh) = listxDropLenPerm is sh
-listxDropLenPerm (_ `PCons` _) ZX = error "Permutation longer than shape"
+ixxDropLenPerm :: forall i is sh. Perm is -> IxX sh i -> IxX (DropLen is sh) i
+ixxDropLenPerm PNil sh = sh
+ixxDropLenPerm (_ `PCons` is) (_ :.% sh) = ixxDropLenPerm is sh
+ixxDropLenPerm (_ `PCons` _) ZIX = error "Permutation longer than shape"
 
-listxPermute :: forall i is sh. Perm is -> ListX sh i -> ListX (Permute is sh) i
-listxPermute PNil _ = ZX
-listxPermute (i `PCons` (is :: Perm is')) (sh :: ListX sh f) =
-  listxIndex i sh ::% listxPermute is sh
+ixxPermute :: forall i is sh. Perm is -> IxX sh i -> IxX (Permute is sh) i
+ixxPermute PNil _ = ZIX
+ixxPermute (i `PCons` (is :: Perm is')) (sh :: IxX sh f) =
+  ixxIndex i sh :.% ixxPermute is sh
 
-listxIndex :: forall j i sh. SNat i -> ListX sh j -> j
-listxIndex SZ (n ::% _) = n
-listxIndex (SS i) (_ ::% sh) = listxIndex i sh
-listxIndex _ ZX = error "Index into empty shape"
-
-listxPermutePrefix :: forall i is sh. Perm is -> ListX sh i -> ListX (PermutePrefix is sh) i
-listxPermutePrefix perm sh = listxAppend (listxPermute perm (listxTakeLenPerm perm sh)) (listxDropLenPerm perm sh)
+ixxIndex :: forall j i sh. SNat i -> IxX sh j -> j
+ixxIndex SZ (n :.% _) = n
+ixxIndex (SS i) (_ :.% sh) = ixxIndex i sh
+ixxIndex _ ZIX = error "Index into empty shape"
 
 ixxPermutePrefix :: forall i is sh. Perm is -> IxX sh i -> IxX (PermutePrefix is sh) i
-ixxPermutePrefix = coerce (listxPermutePrefix @i)
+ixxPermutePrefix perm sh = ixxAppend (ixxPermute perm (ixxTakeLenPerm perm sh)) (ixxDropLenPerm perm sh)
+
 
 -- * Operations on permutations
 
-- 
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