type LHsBindsLR idL idR = Bag (LHsBindLR idL idR)
data HsBindLR idL idR
- = FunBind { -- FunBind is used for both functions f x = e
- -- and variables f = \x -> e
--- Reason 1: Special case for type inference: see TcBinds.tcMonoBinds
---
--- Reason 2: instance decls can only have FunBinds, which is convenient
--- If you change this, you'll need tochange e.g. rnMethodBinds
-
--- But note that the form f :: a->a = ...
--- parses as a pattern binding, just like
--- (f :: a -> a) = ...
+ = -- | FunBind is used for both functions @f x = e@
+ -- and variables @f = \x -> e@
+ --
+ -- Reason 1: Special case for type inference: see 'TcBinds.tcMonoBinds'.
+ --
+ -- Reason 2: Instance decls can only have FunBinds, which is convenient.
+ -- If you change this, you'll need to change e.g. rnMethodBinds
+ --
+ -- But note that the form @f :: a->a = ...@
+ -- parses as a pattern binding, just like
+ -- @(f :: a -> a) = ... @
+ FunBind {
fun_id :: Located idL,
- fun_infix :: Bool, -- True => infix declaration
+ fun_infix :: Bool, -- ^ True => infix declaration
- fun_matches :: MatchGroup idR, -- The payload
+ fun_matches :: MatchGroup idR, -- ^ The payload
- fun_co_fn :: HsWrapper, -- Coercion from the type of the MatchGroup to the type of
+ fun_co_fn :: HsWrapper, -- ^ Coercion from the type of the MatchGroup to the type of
-- the Id. Example:
+ -- @
-- f :: Int -> forall a. a -> a
-- f x y = y
+ -- @
-- Then the MatchGroup will have type (Int -> a' -> a')
-- (with a free type variable a'). The coercion will take
-- a CoreExpr of this type and convert it to a CoreExpr of
-- type Int -> forall a'. a' -> a'
-- Notice that the coercion captures the free a'.
- bind_fvs :: NameSet, -- After the renamer, this contains a superset of the
+ bind_fvs :: NameSet, -- ^ After the renamer, this contains a superset of the
-- Names of the other binders in this binding group that
-- are free in the RHS of the defn
-- Before renaming, and after typechecking,
-- the field is unused; it's just an error thunk
- fun_tick :: Maybe (Int,[idR]) -- This is the (optional) module-local tick number.
+ fun_tick :: Maybe (Int,[idR]) -- ^ This is the (optional) module-local tick number.
}
| PatBind { -- The pattern is never a simple variable;
}
| AbsBinds { -- Binds abstraction; TRANSLATION
- abs_tvs :: [TyVar],
- abs_dicts :: [DictId],
+ abs_tvs :: [TyVar],
+ abs_dicts :: [DictId], -- Includes equality constraints
+
-- AbsBinds only gets used when idL = idR after renaming,
-- but these need to be idL's for the collect... code in HsUtil to have
-- the right type
-- = (\a1..an \x1..xn. [])
| WpCast Coercion -- A cast: [] `cast` co
- -- Guaranteedn not the identity coercion
+ -- Guaranteed not the identity coercion
+
+ | WpApp Var -- [] d the 'd' is a type-class dictionary or coercion variable
- | WpApp Var -- [] d the 'd' is a type-class dictionary
| WpTyApp Type -- [] t the 't' is a type or corecion
+ -- ToDo: it'd be tidier if 't' was always a type (not coercion),
+ -- but that is inconvenient in Inst.instCallDicts
+
| WpLam Var -- \d. [] the 'd' is a type-class dictionary or coercion variable
| WpTyLam TyVar -- \a. [] the 'a' is a type variable (not coercion var)
| WpInline -- inline_me [] Wrap inline around the thing
mkWpTyApps :: [Type] -> HsWrapper
mkWpTyApps tys = mk_co_fn WpTyApp (reverse tys)
-mkWpApps :: [Id] -> HsWrapper
+mkWpApps :: [Var] -> HsWrapper
mkWpApps ids = mk_co_fn WpApp (reverse ids)
mkWpTyLams :: [TyVar] -> HsWrapper
mkWpTyLams ids = mk_co_fn WpTyLam ids
-mkWpLams :: [Id] -> HsWrapper
+mkWpLams :: [Var] -> HsWrapper
mkWpLams ids = mk_co_fn WpLam ids
mk_co_fn :: (a -> HsWrapper) -> [a] -> HsWrapper
\end{code}
\begin{code}
-okBindSig :: NameSet -> LSig Name -> Bool
-okBindSig ns sig = sigForThisGroup ns sig
+okBindSig :: Sig a -> Bool
+okBindSig _ = True
-okHsBootSig :: LSig Name -> Bool
-okHsBootSig (L _ (TypeSig _ _)) = True
-okHsBootSig (L _ (FixSig _)) = True
-okHsBootSig _ = False
+okHsBootSig :: Sig a -> Bool
+okHsBootSig (TypeSig _ _) = True
+okHsBootSig (FixSig _) = True
+okHsBootSig _ = False
-okClsDclSig :: LSig Name -> Bool
-okClsDclSig (L _ (SpecInstSig _)) = False
-okClsDclSig _ = True -- All others OK
+okClsDclSig :: Sig a -> Bool
+okClsDclSig (SpecInstSig _) = False
+okClsDclSig _ = True -- All others OK
-okInstDclSig :: NameSet -> LSig Name -> Bool
-okInstDclSig ns lsig@(L _ sig) = ok ns sig
- where
- ok _ (TypeSig _ _) = False
- ok _ (FixSig _) = False
- ok _ (SpecInstSig _) = True
- ok ns _ = sigForThisGroup ns lsig
+okInstDclSig :: Sig a -> Bool
+okInstDclSig (TypeSig _ _) = False
+okInstDclSig (FixSig _) = False
+okInstDclSig _ = True
sigForThisGroup :: NameSet -> LSig Name -> Bool
sigForThisGroup ns sig
Signature equality is used when checking for duplicate signatures
\begin{code}
-eqHsSig :: LSig Name -> LSig Name -> Bool
+eqHsSig :: Eq a => LSig a -> LSig a -> Bool
eqHsSig (L _ (FixSig (FixitySig n1 _))) (L _ (FixSig (FixitySig n2 _))) = unLoc n1 == unLoc n2
eqHsSig (L _ (TypeSig n1 _)) (L _ (TypeSig n2 _)) = unLoc n1 == unLoc n2
eqHsSig (L _ (InlineSig n1 _)) (L _ (InlineSig n2 _)) = unLoc n1 == unLoc n2