Datatype for: @BindGroup@, @Bind@, @Sig@, @Bind@.
\begin{code}
-{-# OPTIONS -w #-}
+{-# OPTIONS -fno-warn-incomplete-patterns #-}
-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and fix
-- any warnings in the module. See
module HsBinds where
-#include "HsVersions.h"
-
import {-# SOURCE #-} HsExpr ( HsExpr, pprExpr, LHsExpr,
MatchGroup, pprFunBind,
GRHSs, pprPatBind )
import Util
import Var
import Bag
+import FastString
\end{code}
%************************************************************************
Global bindings (where clauses)
\begin{code}
-data HsLocalBinds id -- Bindings in a 'let' expression
- -- or a 'where' clause
- = HsValBinds (HsValBinds id)
- | HsIPBinds (HsIPBinds id)
-
+-- During renaming, we need bindings where the left-hand sides
+-- have been renamed but the the right-hand sides have not.
+-- the ...LR datatypes are parametrized by two id types,
+-- one for the left and one for the right.
+-- Other than during renaming, these will be the same.
+
+type HsLocalBinds id = HsLocalBindsLR id id
+
+data HsLocalBindsLR idL idR -- Bindings in a 'let' expression
+ -- or a 'where' clause
+ = HsValBinds (HsValBindsLR idL idR)
+ | HsIPBinds (HsIPBinds idR)
| EmptyLocalBinds
-data HsValBinds id -- Value bindings (not implicit parameters)
- = ValBindsIn -- Before typechecking
- (LHsBinds id) [LSig id] -- Not dependency analysed
+type HsValBinds id = HsValBindsLR id id
+
+data HsValBindsLR idL idR -- Value bindings (not implicit parameters)
+ = ValBindsIn -- Before typechecking
+ (LHsBindsLR idL idR) [LSig idR] -- Not dependency analysed
-- Recursive by default
- | ValBindsOut -- After renaming
- [(RecFlag, LHsBinds id)] -- Dependency analysed, later bindings
+ | ValBindsOut -- After renaming
+ [(RecFlag, LHsBinds idL)] -- Dependency analysed, later bindings
-- in the list may depend on earlier
-- ones.
[LSig Name]
type LHsBinds id = Bag (LHsBind id)
type DictBinds id = LHsBinds id -- Used for dictionary or method bindings
type LHsBind id = Located (HsBind id)
+type HsBind id = HsBindLR id id
-data HsBind id
- = 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
+type LHsBindLR idL idR = Located (HsBindLR idL idR)
+type LHsBindsLR idL idR = Bag (LHsBindLR idL idR)
--- But note that the form f :: a->a = ...
--- parses as a pattern binding, just like
--- (f :: a -> a) = ...
+data HsBindLR idL idR
+ = -- | 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 id,
+ fun_id :: Located idL,
- fun_infix :: Bool, -- True => infix declaration
+ fun_infix :: Bool, -- ^ True => infix declaration
- fun_matches :: MatchGroup id, -- 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,[id]) -- 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;
-- That case is done by FunBind
- pat_lhs :: LPat id,
- pat_rhs :: GRHSs id,
+ pat_lhs :: LPat idL,
+ pat_rhs :: GRHSs idR,
pat_rhs_ty :: PostTcType, -- Type of the GRHSs
bind_fvs :: NameSet -- Same as for FunBind
}
| VarBind { -- Dictionary binding and suchlike
- var_id :: id, -- All VarBinds are introduced by the type checker
- var_rhs :: LHsExpr id -- Located only for consistency
+ var_id :: idL, -- All VarBinds are introduced by the type checker
+ var_rhs :: LHsExpr idR -- Located only for consistency
}
| AbsBinds { -- Binds abstraction; TRANSLATION
- abs_tvs :: [TyVar],
- abs_dicts :: [DictId],
- abs_exports :: [([TyVar], id, id, [LPrag])], -- (tvs, poly_id, mono_id, prags)
- abs_binds :: LHsBinds id -- The dictionary bindings and typechecked user bindings
+ 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
+ abs_exports :: [([TyVar], idL, idL, [LPrag])], -- (tvs, poly_id, mono_id, prags)
+ abs_binds :: LHsBinds idL -- The dictionary bindings and typechecked user bindings
-- mixed up together; you can tell the dict bindings because
-- they are all VarBinds
}
placeHolderNames = panic "placeHolderNames"
------------
-instance OutputableBndr id => Outputable (HsLocalBinds id) where
+instance (OutputableBndr idL, OutputableBndr idR) => Outputable (HsLocalBindsLR idL idR) where
ppr (HsValBinds bs) = ppr bs
ppr (HsIPBinds bs) = ppr bs
ppr EmptyLocalBinds = empty
-instance OutputableBndr id => Outputable (HsValBinds id) where
+instance (OutputableBndr idL, OutputableBndr idR) => Outputable (HsValBindsLR idL idR) where
ppr (ValBindsIn binds sigs)
= pprValBindsForUser binds sigs
pprValBindsForUser (unionManyBags (map snd sccs)) sigs
where
ppr_scc (rec_flag, binds) = pp_rec rec_flag <+> pprLHsBinds binds
- pp_rec Recursive = ptext SLIT("rec")
- pp_rec NonRecursive = ptext SLIT("nonrec")
+ pp_rec Recursive = ptext (sLit "rec")
+ pp_rec NonRecursive = ptext (sLit "nonrec")
-- *not* pprLHsBinds because we don't want braces; 'let' and
-- 'where' include a list of HsBindGroups and we don't want
-- several groups of bindings each with braces around.
-- Sort by location before printing
-pprValBindsForUser :: (OutputableBndr id1, OutputableBndr id2)
- => LHsBinds id1 -> [LSig id2] -> SDoc
+pprValBindsForUser :: (OutputableBndr idL, OutputableBndr idR, OutputableBndr id2)
+ => LHsBindsLR idL idR -> [LSig id2] -> SDoc
pprValBindsForUser binds sigs
= pprDeeperList vcat (map snd (sort_by_loc decls))
where
decls :: [(SrcSpan, SDoc)]
decls = [(loc, ppr sig) | L loc sig <- sigs] ++
- [(loc, ppr bind) | L loc bind <- bagToList binds]
+ [(loc, ppr bind) | L loc bind <- bagToList binds]
sort_by_loc decls = sortLe (\(l1,_) (l2,_) -> l1 <= l2) decls
-pprLHsBinds :: OutputableBndr id => LHsBinds id -> SDoc
+pprLHsBinds :: (OutputableBndr idL, OutputableBndr idR) => LHsBindsLR idL idR -> SDoc
pprLHsBinds binds
| isEmptyLHsBinds binds = empty
| otherwise = lbrace <+> pprDeeperList vcat (map ppr (bagToList binds)) <+> rbrace
------------
-emptyLocalBinds :: HsLocalBinds a
+emptyLocalBinds :: HsLocalBindsLR a b
emptyLocalBinds = EmptyLocalBinds
-isEmptyLocalBinds :: HsLocalBinds a -> Bool
+isEmptyLocalBinds :: HsLocalBindsLR a b -> Bool
isEmptyLocalBinds (HsValBinds ds) = isEmptyValBinds ds
isEmptyLocalBinds (HsIPBinds ds) = isEmptyIPBinds ds
isEmptyLocalBinds EmptyLocalBinds = True
-isEmptyValBinds :: HsValBinds a -> Bool
+isEmptyValBinds :: HsValBindsLR a b -> Bool
isEmptyValBinds (ValBindsIn ds sigs) = isEmptyLHsBinds ds && null sigs
isEmptyValBinds (ValBindsOut ds sigs) = null ds && null sigs
-emptyValBindsIn, emptyValBindsOut :: HsValBinds a
+emptyValBindsIn, emptyValBindsOut :: HsValBindsLR a b
emptyValBindsIn = ValBindsIn emptyBag []
emptyValBindsOut = ValBindsOut [] []
-emptyLHsBinds :: LHsBinds id
+emptyLHsBinds :: LHsBindsLR idL idR
emptyLHsBinds = emptyBag
-isEmptyLHsBinds :: LHsBinds id -> Bool
+isEmptyLHsBinds :: LHsBindsLR idL idR -> Bool
isEmptyLHsBinds = isEmptyBag
------------
in (fm,gm)
\begin{code}
-instance OutputableBndr id => Outputable (HsBind id) where
+instance (OutputableBndr idL, OutputableBndr idR) => Outputable (HsBindLR idL idR) where
ppr mbind = ppr_monobind mbind
-ppr_monobind :: OutputableBndr id => HsBind id -> SDoc
+ppr_monobind :: (OutputableBndr idL, OutputableBndr idR) => HsBindLR idL idR -> SDoc
ppr_monobind (PatBind { pat_lhs = pat, pat_rhs = grhss }) = pprPatBind pat grhss
-ppr_monobind (VarBind { var_id = var, var_rhs = rhs }) = ppr var <+> equals <+> pprExpr (unLoc rhs)
+ppr_monobind (VarBind { var_id = var, var_rhs = rhs }) = pprBndr CaseBind var <+> equals <+> pprExpr (unLoc rhs)
ppr_monobind (FunBind { fun_id = fun, fun_infix = inf,
fun_matches = matches,
fun_tick = tick }) =
ppr_monobind (AbsBinds { abs_tvs = tyvars, abs_dicts = dictvars,
abs_exports = exports, abs_binds = val_binds })
- = sep [ptext SLIT("AbsBinds"),
+ = sep [ptext (sLit "AbsBinds"),
brackets (interpp'SP tyvars),
brackets (interpp'SP dictvars),
brackets (sep (punctuate comma (map ppr_exp exports)))]
$$ pprLHsBinds val_binds )
where
ppr_exp (tvs, gbl, lcl, prags)
- = vcat [ppr gbl <+> ptext SLIT("<=") <+> ppr tvs <+> ppr lcl,
+ = vcat [ppr gbl <+> ptext (sLit "<=") <+> ppr tvs <+> ppr lcl,
nest 2 (vcat (map (pprPrag gbl) prags))]
\end{code}
| WpCompose HsWrapper HsWrapper -- (\a1..an. []) `WpCompose` (\x1..xn. [])
-- = (\a1..an \x1..xn. [])
- | WpCo Coercion -- A cast: [] `cast` co
- -- Guaranteedn not the identity coercion
+ | WpCast Coercion -- A cast: [] `cast` co
+ -- 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
- | WpLam Id -- \d. [] the 'd' is a type-class dictionary
- | WpTyLam TyVar -- \a. [] the 'a' is a type or coercion variable
+ -- 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
-- Non-empty bindings, so that the identity coercion
-- is always exactly WpHole
-- (would be nicer to be core bindings)
instance Outputable HsWrapper where
- ppr co_fn = pprHsWrapper (ptext SLIT("<>")) co_fn
+ ppr co_fn = pprHsWrapper (ptext (sLit "<>")) co_fn
pprHsWrapper :: SDoc -> HsWrapper -> SDoc
-pprHsWrapper it WpHole = it
-pprHsWrapper it (WpCompose f1 f2) = pprHsWrapper (pprHsWrapper it f2) f1
-pprHsWrapper it (WpCo co) = sep [it, nest 2 (ptext SLIT("`cast`") <+> pprParendType co)]
-pprHsWrapper it (WpApp id) = sep [it, nest 2 (ppr id)]
-pprHsWrapper it (WpTyApp ty) = sep [it, ptext SLIT("@") <+> pprParendType ty]
-pprHsWrapper it (WpLam id) = sep [ptext SLIT("\\") <> pprBndr LambdaBind id <> dot, it]
-pprHsWrapper it (WpTyLam tv) = sep [ptext SLIT("/\\") <> pprBndr LambdaBind tv <> dot, it]
-pprHsWrapper it (WpLet binds) = sep [ptext SLIT("let") <+> braces (ppr binds), it]
+pprHsWrapper it wrap =
+ let
+ help it WpHole = it
+ help it (WpCompose f1 f2) = help (help it f2) f1
+ help it (WpCast co) = sep [it, nest 2 (ptext (sLit "`cast`") <+> pprParendType co)]
+ help it (WpApp id) = sep [it, nest 2 (ppr id)]
+ help it (WpTyApp ty) = sep [it, ptext (sLit "@") <+> pprParendType ty]
+ help it (WpLam id) = sep [ptext (sLit "\\") <> pprBndr LambdaBind id <> dot, it]
+ help it (WpTyLam tv) = sep [ptext (sLit "/\\") <> pprBndr LambdaBind tv <> dot, it]
+ help it (WpLet binds) = sep [ptext (sLit "let") <+> braces (ppr binds), it]
+ help it WpInline = sep [ptext (sLit "_inline_me_"), it]
+ in
+ -- in debug mode, print the wrapper
+ -- otherwise just print what's inside
+ getPprStyle (\ s -> if debugStyle s then (help it wrap) else it)
(<.>) :: HsWrapper -> HsWrapper -> HsWrapper
WpHole <.> c = c
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
isIdHsWrapper :: HsWrapper -> Bool
isIdHsWrapper WpHole = True
-isIdHsWrapper other = False
+isIdHsWrapper _ = False
\end{code}
| SpecPrag
(HsExpr Id) -- An expression, of the given specialised type, which
PostTcType -- specialises the polymorphic function
- [Id] -- Dicts mentioned free in the expression
- -- Apr07: I think this is pretty useless
- -- see Note [Const rule dicts] in DsBinds
InlineSpec -- Inlining spec for the specialised function
+isInlinePrag :: Prag -> Bool
isInlinePrag (InlinePrag _) = True
-isInlinePrag prag = False
+isInlinePrag _ = False
+isSpecPrag :: Prag -> Bool
isSpecPrag (SpecPrag {}) = True
-isSpecPrag prag = False
+isSpecPrag _ = False
\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 sig = False
+okHsBootSig :: Sig a -> Bool
+okHsBootSig (TypeSig _ _) = True
+okHsBootSig (FixSig _) = True
+okHsBootSig _ = False
-okClsDclSig :: LSig Name -> Bool
-okClsDclSig (L _ (SpecInstSig _)) = False
-okClsDclSig sig = 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 ns (TypeSig _ _) = False
- ok ns (FixSig _) = False
- ok ns (SpecInstSig _) = True
- ok ns sig = sigForThisGroup ns lsig
+okInstDclSig :: Sig a -> Bool
+okInstDclSig (TypeSig _ _) = False
+okInstDclSig (FixSig _) = False
+okInstDclSig _ = True
sigForThisGroup :: NameSet -> LSig Name -> Bool
sigForThisGroup ns sig
sigNameNoLoc (SpecSig n _ _) = Just (unLoc n)
sigNameNoLoc (InlineSig n _) = Just (unLoc n)
sigNameNoLoc (FixSig (FixitySig n _)) = Just (unLoc n)
-sigNameNoLoc other = Nothing
+sigNameNoLoc _ = Nothing
isFixityLSig :: LSig name -> Bool
isFixityLSig (L _ (FixSig {})) = True
isVanillaLSig :: LSig name -> Bool
isVanillaLSig (L _(TypeSig {})) = True
-isVanillaLSig sig = False
+isVanillaLSig _ = False
isSpecLSig :: LSig name -> Bool
isSpecLSig (L _(SpecSig {})) = True
-isSpecLSig sig = False
+isSpecLSig _ = False
+isSpecInstLSig :: LSig name -> Bool
isSpecInstLSig (L _ (SpecInstSig {})) = True
-isSpecInstLSig sig = False
+isSpecInstLSig _ = False
isPragLSig :: LSig name -> Bool
-- Identifies pragmas
isPragLSig (L _ (SpecSig {})) = True
isPragLSig (L _ (InlineSig {})) = True
-isPragLSig other = False
+isPragLSig _ = False
isInlineLSig :: LSig name -> Bool
-- Identifies inline pragmas
isInlineLSig (L _ (InlineSig {})) = True
-isInlineLSig other = False
-
-hsSigDoc (TypeSig {}) = ptext SLIT("type signature")
-hsSigDoc (SpecSig {}) = ptext SLIT("SPECIALISE pragma")
-hsSigDoc (InlineSig _ spec) = ppr spec <+> ptext SLIT("pragma")
-hsSigDoc (SpecInstSig {}) = ptext SLIT("SPECIALISE instance pragma")
-hsSigDoc (FixSig {}) = ptext SLIT("fixity declaration")
+isInlineLSig _ = False
+
+hsSigDoc :: Sig name -> SDoc
+hsSigDoc (TypeSig {}) = ptext (sLit "type signature")
+hsSigDoc (SpecSig {}) = ptext (sLit "SPECIALISE pragma")
+hsSigDoc (InlineSig {}) = ptext (sLit "INLINE pragma")
+hsSigDoc (SpecInstSig {}) = ptext (sLit "SPECIALISE instance pragma")
+hsSigDoc (FixSig {}) = ptext (sLit "fixity declaration")
\end{code}
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 s1)) (L _ (InlineSig n2 s2)) = s1 == s2 && unLoc n1 == unLoc n2
+eqHsSig (L _ (InlineSig n1 _)) (L _ (InlineSig n2 _)) = unLoc n1 == unLoc n2
-- For specialisations, we don't have equality over
-- HsType, so it's not convenient to spot duplicate
-- specialisations here. Check for this later, when we're in Type land
ppr_sig (FixSig fix_sig) = ppr fix_sig
ppr_sig (SpecSig var ty inl) = pragBrackets (pprSpec var ty inl)
ppr_sig (InlineSig var inl) = pragBrackets (ppr inl <+> ppr var)
-ppr_sig (SpecInstSig ty) = pragBrackets (ptext SLIT("SPECIALIZE instance") <+> ppr ty)
+ppr_sig (SpecInstSig ty) = pragBrackets (ptext (sLit "SPECIALIZE instance") <+> ppr ty)
instance Outputable name => Outputable (FixitySig name) where
ppr (FixitySig name fixity) = sep [ppr fixity, ppr name]
pragBrackets :: SDoc -> SDoc
-pragBrackets doc = ptext SLIT("{-#") <+> doc <+> ptext SLIT("#-}")
+pragBrackets doc = ptext (sLit "{-#") <+> doc <+> ptext (sLit "#-}")
pprVarSig :: (Outputable id, Outputable ty) => id -> ty -> SDoc
pprVarSig var ty = sep [ppr var <+> dcolon, nest 2 (ppr ty)]
pprSpec :: (Outputable id, Outputable ty) => id -> ty -> InlineSpec -> SDoc
-pprSpec var ty inl = sep [ptext SLIT("SPECIALIZE") <+> ppr inl <+> pprVarSig var ty]
+pprSpec var ty inl = sep [ptext (sLit "SPECIALIZE") <+> ppr inl <+> pprVarSig var ty]
pprPrag :: Outputable id => id -> LPrag -> SDoc
-pprPrag var (L _ (InlinePrag inl)) = ppr inl <+> ppr var
-pprPrag var (L _ (SpecPrag expr ty _ inl)) = pprSpec var ty inl
+pprPrag var (L _ (InlinePrag inl)) = ppr inl <+> ppr var
+pprPrag var (L _ (SpecPrag _expr ty inl)) = pprSpec var ty inl
\end{code}