diff options
Diffstat (limited to 'testsuite/tests/typecheck/should_run/tcrun014.hs')
| -rw-r--r-- | testsuite/tests/typecheck/should_run/tcrun014.hs | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_run/tcrun014.hs b/testsuite/tests/typecheck/should_run/tcrun014.hs new file mode 100644 index 0000000000..751e9aa5bf --- /dev/null +++ b/testsuite/tests/typecheck/should_run/tcrun014.hs @@ -0,0 +1,22 @@ +-- !!! Newtypes + +-- This one made ghc 5.01 (after newtype squashing) fall over +-- by generating Core code that contained a pattern match on +-- the InPE data constructor (which doesn't exist) + +module Main where + + +data Expr e = One e | Many [e] +newtype PExpr a = InPE (Expr (PExpr a), Int) + +one :: Int -> PExpr e -> PExpr e +one l x = InPE (One (plus1 x), l) + +plus1 :: PExpr a -> PExpr a +plus1 x@(InPE (_, loc)) = InPE (Many [plus1 x], loc) + +get :: PExpr e -> Int +get (InPE (_,l)) = l + +main = print (get (plus1 (InPE (Many [], 0)))) |