Add COMPLETE pragma for Vec: Nil, :> (#2716)

changelog/2024-05-07T22_51_59+10_00_add_vec_complete_pragma

@@ -0,0 +1 @@
+ADDED: The Vec type now has a [COMPLETE pragma](https://ghc.gitlab.haskell.org/ghc/doc/users_guide/exts/pragmas.html#complete-pragma) to avoid incomplete pattern matches when using the `(:>)` pattern.

clash-prelude/src/Clash/Sized/Vector.hs

@@ -2,6 +2,7 @@
 Copyright  :  (C) 2013-2016, University of Twente,
                   2017     , Myrtle Software Ltd
                   2022-2023, QBayLogic B.V.
+                  2024,      Alex Mason
 License    :  BSD2 (see the file LICENSE)
 Maintainer :  QBayLogic B.V. <[email protected]>
 -}
@@ -180,6 +181,8 @@ data Vec :: Nat -> Type -> Type where
   Nil  :: Vec 0 a
   Cons :: a -> Vec n a -> Vec (n + 1) a
 
+{-# COMPLETE Nil, (:>) #-}
+
 -- | In many cases, this Generic instance only allows generic
 -- functions/instances over vectors of at least size 1, due to the
 -- /n-1/ in the /Rep (Vec n a)/ definition.