X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fprelude%2FTysWiredIn.lhs;fp=compiler%2Fprelude%2FTysWiredIn.lhs;h=16ebf58e5120d5aba13c91dfb375f3eeba870c51;hp=cf54f26043eb68a538fccc14cb60e56d6b00c510;hb=69f8ed93800605d8df011388450d6d3bb9ca6071;hpb=6582768fd0065b9aa4abdd93fdfa6ac1d047482b

diff --git a/compiler/prelude/TysWiredIn.lhs b/compiler/prelude/TysWiredIn.lhs
index cf54f26..16ebf58 100644
--- a/compiler/prelude/TysWiredIn.lhs
+++ b/compiler/prelude/TysWiredIn.lhs
@@ -534,11 +534,13 @@ done by enumeration\srcloc{lib/prelude/InTup?.hs}.
 \end{itemize}
 
 \begin{code}
-mkTupleTy :: Boxity -> Int -> [Type] -> Type
-mkTupleTy boxity arity tys = mkTyConApp (tupleTyCon boxity arity) tys
+mkTupleTy :: Boxity -> [Type] -> Type
+-- Special case for *boxed* 1-tuples, which are represented by the type itself
+mkTupleTy boxity [ty] | Boxed <- boxity = ty
+mkTupleTy boxity tys = mkTyConApp (tupleTyCon boxity (length tys)) tys
 
 unitTy :: Type
-unitTy = mkTupleTy Boxed 0 []
+unitTy = mkTupleTy Boxed []
 \end{code}
 
 %************************************************************************