diff options
Diffstat (limited to 'ghc/compiler/hsSyn/HsBinds.lhs')
| -rw-r--r-- | ghc/compiler/hsSyn/HsBinds.lhs | 293 |
1 files changed, 197 insertions, 96 deletions
diff --git a/ghc/compiler/hsSyn/HsBinds.lhs b/ghc/compiler/hsSyn/HsBinds.lhs index 47302c5050..0646b23634 100644 --- a/ghc/compiler/hsSyn/HsBinds.lhs +++ b/ghc/compiler/hsSyn/HsBinds.lhs @@ -17,12 +17,12 @@ import {-# SOURCE #-} HsPat ( LPat ) import HsTypes ( LHsType, PostTcType ) import Name ( Name ) -import NameSet ( NameSet, elemNameSet, nameSetToList ) +import NameSet ( NameSet, elemNameSet ) import BasicTypes ( IPName, RecFlag(..), Activation(..), Fixity ) import Outputable import SrcLoc ( Located(..), unLoc ) -import Var ( TyVar ) -import Bag ( Bag, emptyBag, isEmptyBag, bagToList ) +import Var ( TyVar, DictId, Id ) +import Bag ( Bag, emptyBag, isEmptyBag, bagToList, unionBags ) \end{code} %************************************************************************ @@ -34,65 +34,25 @@ import Bag ( Bag, emptyBag, isEmptyBag, bagToList ) Global bindings (where clauses) \begin{code} -data HsBindGroup id - = HsBindGroup -- A mutually recursive group - (LHsBinds id) - [LSig id] -- Empty on typechecker output, Type Signatures - RecFlag - - | HsIPBinds - [LIPBind id] -- Not allowed at top level - -instance OutputableBndr id => Outputable (HsBindGroup id) where - ppr (HsBindGroup binds sigs is_rec) - = vcat [ppr_isrec, - vcat (map ppr sigs), - vcat (map ppr (bagToList binds)) - -- *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. - ] - where - ppr_isrec = getPprStyle $ \ sty -> - if userStyle sty then empty else - case is_rec of - Recursive -> ptext SLIT("{- rec -}") - NonRecursive -> ptext SLIT("{- nonrec -}") - - ppr (HsIPBinds ipbinds) - = vcat (map ppr ipbinds) +data HsLocalBinds id -- Bindings in a 'let' expression + -- or a 'where' clause + = HsValBinds (HsValBinds id) + | HsIPBinds (HsIPBinds id) + | EmptyLocalBinds --- ----------------------------------------------------------------------------- --- Implicit parameter bindings - -type LIPBind id = Located (IPBind id) - --- | Implicit parameter bindings. -data IPBind id - = IPBind - (IPName id) - (LHsExpr id) +data HsValBinds id -- Value bindings (not implicit parameters) + = ValBindsIn -- Before typechecking + (LHsBinds id) [LSig id] -- Not dependency analysed + -- Recursive by default -instance (OutputableBndr id) => Outputable (IPBind id) where - ppr (IPBind id rhs) = pprBndr LetBind id <+> equals <+> pprExpr (unLoc rhs) + | ValBindsOut -- After typechecking + [(RecFlag, LHsBinds id)] -- Dependency analysed --- ----------------------------------------------------------------------------- type LHsBinds id = Bag (LHsBind id) type DictBinds id = LHsBinds id -- Used for dictionary or method bindings type LHsBind id = Located (HsBind id) -emptyLHsBinds :: LHsBinds id -emptyLHsBinds = emptyBag - -isEmptyLHsBinds :: LHsBinds id -> Bool -isEmptyLHsBinds = isEmptyBag - -pprLHsBinds :: OutputableBndr id => LHsBinds id -> SDoc -pprLHsBinds binds - | isEmptyLHsBinds binds = empty - | otherwise = lbrace <+> vcat (map ppr (bagToList binds)) <+> rbrace - data HsBind id = FunBind (Located id) -- Used for both functions f x = e @@ -105,28 +65,102 @@ data HsBind id -- change e.g. rnMethodBinds Bool -- True => infix declaration (MatchGroup id) + 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 | PatBind (LPat id) -- The pattern is never a simple variable; -- That case is done by FunBind (GRHSs id) PostTcType -- Type of the GRHSs - - | VarBind id (Located (HsExpr id)) -- Dictionary binding and suchlike; - -- located only for consistency - - | AbsBinds -- Binds abstraction; TRANSLATION - [TyVar] -- Type variables - [id] -- Dicts - [([TyVar], id, id)] -- (type variables, polymorphic, momonmorphic) triples - NameSet -- Set of *polymorphic* variables that have an INLINE pragma - (LHsBinds id) -- The "business end" - - -- Creates bindings for *new* (polymorphic, overloaded) locals - -- in terms of *old* (monomorphic, non-overloaded) ones. + NameSet -- Same as for FunBind + + | VarBind id (Located (HsExpr id)) -- Dictionary binding and suchlike + -- All VarBinds are introduced by the type checker + -- Located only for consistency + + | AbsBinds -- Binds abstraction; TRANSLATION + [TyVar] -- Type variables + [DictId] -- Dicts + [([TyVar], id, id, [Prag])] -- (tvs, poly_id, mono_id, prags) + (LHsBinds id) -- The dictionary bindings and typechecked user bindings + -- mixed up together; you can tell the dict bindings because + -- they are all VarBinds + + -- Consider (AbsBinds tvs ds [(ftvs, poly_f, mono_f) binds] + -- + -- Creates bindings for (polymorphic, overloaded) poly_f + -- in terms of monomorphic, non-overloaded mono_f + -- + -- Invariants: + -- 1. 'binds' binds mono_f + -- 2. ftvs is a subset of tvs + -- 3. ftvs includes all tyvars free in ds -- -- See section 9 of static semantics paper for more details. -- (You can get a PhD for explaining the True Meaning -- of this last construct.) + +placeHolderNames :: NameSet +-- Used for the NameSet in FunBind and PatBind prior to the renamer +placeHolderNames = panic "placeHolderNames" + +------------ +instance OutputableBndr id => Outputable (HsLocalBinds id) where + ppr (HsValBinds bs) = ppr bs + ppr (HsIPBinds bs) = ppr bs + ppr EmptyLocalBinds = empty + +instance OutputableBndr id => Outputable (HsValBinds id) where + ppr (ValBindsIn binds sigs) + = vcat [vcat (map ppr sigs), + vcat (map ppr (bagToList binds)) + -- *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. + ] + ppr (ValBindsOut sccs) = vcat (map ppr_scc sccs) + where + ppr_scc (rec_flag, binds) = pp_rec rec_flag <+> pprLHsBinds binds + pp_rec Recursive = ptext SLIT("rec") + pp_rec NonRecursive = ptext SLIT("nonrec") + +pprLHsBinds :: OutputableBndr id => LHsBinds id -> SDoc +pprLHsBinds binds + | isEmptyLHsBinds binds = empty + | otherwise = lbrace <+> vcat (map ppr (bagToList binds)) <+> rbrace + +------------ +emptyLocalBinds :: HsLocalBinds a +emptyLocalBinds = EmptyLocalBinds + +isEmptyLocalBinds :: HsLocalBinds a -> Bool +isEmptyLocalBinds (HsValBinds ds) = isEmptyValBinds ds +isEmptyLocalBinds (HsIPBinds ds) = isEmptyIPBinds ds +isEmptyLocalBinds EmptyLocalBinds = True + +isEmptyValBinds :: HsValBinds a -> Bool +isEmptyValBinds (ValBindsIn ds sigs) = isEmptyLHsBinds ds && null sigs +isEmptyValBinds (ValBindsOut ds) = null ds + +emptyValBindsIn, emptyValBindsOut :: HsValBinds a +emptyValBindsIn = ValBindsIn emptyBag [] +emptyValBindsOut = ValBindsOut [] + +emptyLHsBinds :: LHsBinds id +emptyLHsBinds = emptyBag + +isEmptyLHsBinds :: LHsBinds id -> Bool +isEmptyLHsBinds = isEmptyBag + +------------ +plusHsValBinds :: HsValBinds a -> HsValBinds a -> HsValBinds a +plusHsValBinds (ValBindsIn ds1 sigs1) (ValBindsIn ds2 sigs2) + = ValBindsIn (ds1 `unionBags` ds2) (sigs1 ++ sigs2) +plusHsValBinds (ValBindsOut ds1) (ValBindsOut ds2) + = ValBindsOut (ds1 ++ ds2) \end{code} What AbsBinds means @@ -159,26 +193,61 @@ instance OutputableBndr id => Outputable (HsBind id) where ppr_monobind :: OutputableBndr id => HsBind id -> SDoc -ppr_monobind (PatBind pat grhss ty) = pprPatBind pat grhss -ppr_monobind (VarBind var rhs) = ppr var <+> equals <+> pprExpr (unLoc rhs) -ppr_monobind (FunBind fun inf matches) = pprFunBind (unLoc fun) matches +ppr_monobind (PatBind pat grhss _ _) = pprPatBind pat grhss +ppr_monobind (VarBind var rhs) = ppr var <+> equals <+> pprExpr (unLoc rhs) +ppr_monobind (FunBind fun inf matches _) = pprFunBind (unLoc fun) matches -- ToDo: print infix if appropriate -ppr_monobind (AbsBinds tyvars dictvars exports inlines val_binds) +ppr_monobind (AbsBinds tyvars dictvars exports val_binds) = sep [ptext SLIT("AbsBinds"), brackets (interpp'SP tyvars), brackets (interpp'SP dictvars), - brackets (sep (punctuate comma (map ppr exports))), - brackets (interpp'SP (nameSetToList inlines))] + brackets (sep (punctuate comma (map ppr_exp exports)))] $$ - nest 4 ( vcat [pprBndr LetBind x | (_,x,_) <- exports] + nest 2 ( vcat [pprBndr LetBind x | (_,x,_,_) <- exports] -- Print type signatures - $$ - pprLHsBinds val_binds ) + $$ pprLHsBinds val_binds ) + where + ppr_exp (tvs, gbl, lcl, prags) + = vcat [ppr gbl <+> ptext SLIT("<=") <+> ppr tvs <+> ppr lcl, + nest 2 (vcat (map (pprPrag gbl) prags))] \end{code} %************************************************************************ %* * + Implicit parameter bindings +%* * +%************************************************************************ + +\begin{code} +data HsIPBinds id + = IPBinds + [LIPBind id] + (DictBinds id) -- Only in typechecker output; binds + -- uses of the implicit parameters + +isEmptyIPBinds :: HsIPBinds id -> Bool +isEmptyIPBinds (IPBinds is ds) = null is && isEmptyBag ds + +type LIPBind id = Located (IPBind id) + +-- | Implicit parameter bindings. +data IPBind id + = IPBind + (IPName id) + (LHsExpr id) + +instance (OutputableBndr id) => Outputable (HsIPBinds id) where + ppr (IPBinds bs ds) = vcat (map ppr bs) + $$ pprLHsBinds ds + +instance (OutputableBndr id) => Outputable (IPBind id) where + ppr (IPBind id rhs) = pprBndr LetBind id <+> equals <+> pprExpr (unLoc rhs) +\end{code} + + +%************************************************************************ +%* * \subsection{@Sig@: type signatures and value-modifying user pragmas} %* * %************************************************************************ @@ -209,12 +278,34 @@ data Sig name type LFixitySig name = Located (FixitySig name) data FixitySig name = FixitySig (Located name) Fixity + +-- A Prag conveys pragmas from the type checker to the desugarer +data Prag + = InlinePrag + Bool -- True <=> INLINE, False <=> NOINLINE + Activation + + | SpecPrag + (HsExpr Id) -- An expression, of the given specialised type, which + PostTcType -- specialises the polymorphic function + [Id] -- Dicts mentioned free in the expression + +isInlinePrag (InlinePrag _ _) = True +isInlinePrag prag = False + +isSpecPrag (SpecPrag _ _ _) = True +isSpecPrag prag = False \end{code} \begin{code} okBindSig :: NameSet -> LSig Name -> Bool okBindSig ns sig = sigForThisGroup ns sig +okHsBootSig :: LSig Name -> Bool +okHsBootSig (L _ (Sig _ _)) = True +okHsBootSig (L _ (FixSig _)) = True +okHsBootSig sig = False + okClsDclSig :: LSig Name -> Bool okClsDclSig (L _ (SpecInstSig _)) = False okClsDclSig sig = True -- All others OK @@ -250,11 +341,17 @@ isVanillaLSig :: LSig name -> Bool isVanillaLSig (L _(Sig name _)) = True isVanillaLSig sig = False +isSpecLSig :: LSig name -> Bool +isSpecLSig (L _(SpecSig name _)) = True +isSpecLSig sig = False + +isSpecInstLSig (L _ (SpecInstSig _)) = True +isSpecInstLSig sig = False + isPragLSig :: LSig name -> Bool -- Identifies pragmas isPragLSig (L _ (SpecSig _ _)) = True isPragLSig (L _ (InlineSig _ _ _)) = True -isPragLSig (L _ (SpecInstSig _)) = True isPragLSig other = False hsSigDoc (Sig _ _) = ptext SLIT("type signature") @@ -268,10 +365,10 @@ hsSigDoc (FixSig (FixitySig _ _)) = ptext SLIT("fixity declaration") Signature equality is used when checking for duplicate signatures \begin{code} -eqHsSig :: Sig Name -> Sig Name -> Bool -eqHsSig (FixSig (FixitySig n1 _)) (FixSig (FixitySig n2 _)) = unLoc n1 == unLoc n2 -eqHsSig (Sig n1 _) (Sig n2 _) = unLoc n1 == unLoc n2 -eqHsSig (InlineSig b1 n1 _) (InlineSig b2 n2 _) = b1 == b2 && unLoc n1 == unLoc n2 +eqHsSig :: LSig Name -> LSig Name -> Bool +eqHsSig (L _ (FixSig (FixitySig n1 _))) (L _ (FixSig (FixitySig n2 _))) = unLoc n1 == unLoc n2 +eqHsSig (L _ (Sig n1 _)) (L _ (Sig n2 _)) = unLoc n1 == unLoc n2 +eqHsSig (L _ (InlineSig b1 n1 _)) (L _ (InlineSig b2 n2 _)) = b1 == b2 && 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 @@ -283,25 +380,29 @@ instance (OutputableBndr name) => Outputable (Sig name) where ppr sig = ppr_sig sig ppr_sig :: OutputableBndr name => Sig name -> SDoc -ppr_sig (Sig var ty) - = sep [ppr var <+> dcolon, nest 4 (ppr ty)] +ppr_sig (Sig var ty) = pprVarSig (unLoc var) ty +ppr_sig (FixSig fix_sig) = ppr fix_sig +ppr_sig (SpecSig var ty) = pragBrackets (pprSpec var ty) +ppr_sig (InlineSig inl var phase) = pragBrackets (pprInline var inl phase) +ppr_sig (SpecInstSig ty) = pragBrackets (ptext SLIT("SPECIALIZE instance") <+> ppr ty) -ppr_sig (SpecSig var ty) - = sep [ hsep [text "{-# SPECIALIZE", ppr var, dcolon], - nest 4 (ppr ty <+> text "#-}") - ] +instance Outputable name => Outputable (FixitySig name) where + ppr (FixitySig name fixity) = sep [ppr fixity, ppr name] -ppr_sig (InlineSig True var phase) - = hsep [text "{-# INLINE", ppr phase, ppr var, text "#-}"] +pragBrackets :: SDoc -> SDoc +pragBrackets doc = ptext SLIT("{-#") <+> doc <+> ptext SLIT("#-}") -ppr_sig (InlineSig False var phase) - = hsep [text "{-# NOINLINE", ppr phase, ppr var, text "#-}"] +pprInline :: Outputable id => id -> Bool -> Activation -> SDoc +pprInline var True phase = hsep [ptext SLIT("INLINE"), ppr phase, ppr var] +pprInline var False phase = hsep [ptext SLIT("NOINLINE"), ppr phase, ppr var] -ppr_sig (SpecInstSig ty) - = hsep [text "{-# SPECIALIZE instance", ppr ty, text "#-}"] +pprVarSig :: (Outputable id, Outputable ty) => id -> ty -> SDoc +pprVarSig var ty = sep [ppr var <+> dcolon, nest 2 (ppr ty)] -ppr_sig (FixSig fix_sig) = ppr fix_sig +pprSpec :: (Outputable id, Outputable ty) => id -> ty -> SDoc +pprSpec var ty = sep [ptext SLIT("SPECIALIZE") <+> pprVarSig var ty] -instance Outputable name => Outputable (FixitySig name) where - ppr (FixitySig name fixity) = sep [ppr fixity, ppr name] +pprPrag :: Outputable id => id -> Prag -> SDoc +pprPrag var (InlinePrag inl act) = pprInline var inl act +pprPrag var (SpecPrag expr ty _) = pprSpec var ty \end{code} |