From 816249cd59a7e243bec82651e2def22f8c3b439c Mon Sep 17 00:00:00 2001
From: Mikolaj Konarski <mikolaj.konarski@funktory.com>
Date: Sun, 15 Mar 2026 10:34:19 +0100
Subject: Work around the following GHC bug in GHC 9.10.3:
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src/Data/Array/Nested/Mixed.hs:1045:13: error: [GHC-83865]
    • Couldn't match type ‘i0’ with ‘Int’
      Expected: ShX sh i0
        Actual: ShX sh1 Int
      ‘i0’ is untouchable
        inside the constraints: (n1 : sh1)
                                ~ (AddMaybe (AddMaybe i n) k : sh)
        bound by UnkSkol (please report this as a bug)
                 Call stack:
                     CallStack (from HasCallStack):
                       unkSkolAnon, called at compiler/GHC/Tc/Types/Origin.hs:331:42 in ghc-9.10.3-b4c3:GHC.Tc.Types.Origin
                       unkSkol, called at compiler/GHC/Tc/Gen/Pat.hs:1275:49 in ghc-9.10.3-b4c3:GHC.Tc.Gen.Pat
        at src/Data/Array/Nested/Mixed.hs:1045:7-14
---
 src/Data/Array/Nested/Mixed.hs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

(limited to 'src/Data/Array')

diff --git a/src/Data/Array/Nested/Mixed.hs b/src/Data/Array/Nested/Mixed.hs
index 0766e8c..a761503 100644
--- a/src/Data/Array/Nested/Mixed.hs
+++ b/src/Data/Array/Nested/Mixed.hs
@@ -1041,11 +1041,11 @@ msliceSN i n arr =
 
 mslice :: forall i n k sh a. Elt a
        => SMayNat Int i -> SMayNat Int n -> SMayNat Int k -> Mixed (AddMaybe (AddMaybe i n) k : sh) a -> Mixed (n : sh) a
-mslice i n k arr =
-  let _ :$% sh = mshape arr
-      uarr = mcastPartial (ssxFromShX $ smnAddMaybe (smnAddMaybe i n) k :$% ZSX) (SUnknown () :!% ZKX) Proxy arr
-  in mcastPartial (SUnknown () :!% ZKX) (ssxFromShX $ n :$% ZSX) Proxy
-     $ mlift (SUnknown () :!% ssxFromShX sh) (\_ -> X.sliceU (fromSMayNat' i) (fromSMayNat' n)) uarr
+mslice i n k arr = case mshape arr of
+  _ :$% sh ->
+    let uarr = mcastPartial (ssxFromShX $ smnAddMaybe (smnAddMaybe i n) k :$% ZSX) (SUnknown () :!% ZKX) Proxy arr
+    in mcastPartial (SUnknown () :!% ZKX) (ssxFromShX $ n :$% ZSX) Proxy
+       $ mlift (SUnknown () :!% ssxFromShX sh) (\_ -> X.sliceU (fromSMayNat' i) (fromSMayNat' n)) uarr
 
 mrev1 :: Elt a => Mixed (n : sh) a -> Mixed (n : sh) a
 mrev1 arr = mlift (ssxFromShX (mshape arr)) (\_ -> X.rev1) arr
-- 
cgit v1.2.3-70-g09d2