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|
{-# LANGUAGE TemplateHaskell, GADTs, ExplicitForAll, KindSignatures,
TypeFamilies, DataKinds #-}
module T10828 where
import Language.Haskell.TH
import System.IO
$( do { decl <- [d| data family D a :: * -> *
data instance D Int Bool :: * where
DInt :: D Int Bool
data E where
MkE :: a -> E
data Foo a b where
MkFoo, MkFoo' :: a -> Foo a b
newtype Bar :: * -> Bool -> * where
MkBar :: a -> Bar a b
|]
; runIO $ putStrLn (pprint decl) >> hFlush stdout
; return decl }
)
-- data T a :: * where
-- MkT :: a -> a -> T a
-- MkC :: forall a b. (a ~ Int) => { foo :: a, bar :: b } -> T Int
$( return
[ DataD [] (mkName "T")
[ PlainTV (mkName "a") ]
(Just StarT)
[ GadtC [(mkName "MkT")]
[ ( Bang NoSourceUnpackedness NoSourceStrictness
, VarT (mkName "a")
)
, ( Bang NoSourceUnpackedness NoSourceStrictness
, VarT (mkName "a")
)
]
(AppT (ConT (mkName "T"))
(VarT (mkName "a")))
, ForallC [PlainTV (mkName "a"), PlainTV (mkName "b")]
[AppT (AppT EqualityT (VarT $ mkName "a" ) )
(ConT $ mkName "Int") ] $
RecGadtC [(mkName "MkC")]
[ ( mkName "foo"
, Bang NoSourceUnpackedness NoSourceStrictness
, VarT (mkName "a")
)
, ( mkName "bar"
, Bang NoSourceUnpackedness NoSourceStrictness
, VarT (mkName "b")
)
]
(AppT (ConT (mkName "T"))
(ConT (mkName "Int"))) ]
[] ])
$( do { -- test reification
TyConI dec <- runQ $ reify (mkName "T")
; runIO $ putStrLn (pprint dec) >> hFlush stdout
-- test quoting
; d <- runQ $ [d|
data T' a :: * where
MkT' :: a -> a -> T' a
MkC' :: forall a b. (a ~ Int) => { foo :: a, bar :: b }
-> T' Int |]
; runIO $ putStrLn (pprint d) >> hFlush stdout
; return [] } )
|
