X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FhsSyn%2FHsBinds.lhs;h=5871914ad864a4ec6152b8e8b8f89a35f0fecb1c;hp=6c46fa2d13f82f444c2011eb3019375613950274;hb=2d4d636af091b8da27466b5cf90011395a9c2f66;hpb=e2cd7b279553e3015d4683c69d02118c4436b09a diff --git a/compiler/hsSyn/HsBinds.lhs b/compiler/hsSyn/HsBinds.lhs index 6c46fa2..5871914 100644 --- a/compiler/hsSyn/HsBinds.lhs +++ b/compiler/hsSyn/HsBinds.lhs @@ -7,11 +7,17 @@ Datatype for: @BindGroup@, @Bind@, @Sig@, @Bind@. \begin{code} -module HsBinds where +{-# 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 +-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings +-- for details +{-# LANGUAGE DeriveDataTypeable #-} -#include "HsVersions.h" +module HsBinds where -import {-# SOURCE #-} HsExpr ( HsExpr, pprExpr, LHsExpr, +import {-# SOURCE #-} HsExpr ( pprExpr, LHsExpr, MatchGroup, pprFunBind, GRHSs, pprPatBind ) import {-# SOURCE #-} HsPat ( LPat ) @@ -26,8 +32,14 @@ import BasicTypes import Outputable import SrcLoc import Util +import VarEnv import Var import Bag +import Unique +import FastString + +import Data.IORef( IORef ) +import Data.Data hiding ( Fixity ) \end{code} %************************************************************************ @@ -39,86 +51,112 @@ import Bag 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 + deriving (Data, Typeable) + +type HsValBinds id = HsValBindsLR id id -data HsValBinds id -- Value bindings (not implicit parameters) - = ValBindsIn -- Before typechecking - (LHsBinds id) [LSig id] -- Not dependency analysed +data HsValBindsLR idL idR -- Value bindings (not implicit parameters) + = ValBindsIn -- Before renaming RHS; idR is always RdrName + (LHsBindsLR idL idR) [LSig idR] -- Not dependency analysed -- Recursive by default - | ValBindsOut -- After renaming - [(RecFlag, LHsBinds id)] -- Dependency analysed, later bindings + | ValBindsOut -- After renaming RHS; idR can be Name or Id + [(RecFlag, LHsBinds idL)] -- Dependency analysed, later bindings -- in the list may depend on earlier -- ones. [LSig Name] + deriving (Data, Typeable) -type LHsBinds id = Bag (LHsBind id) -type DictBinds id = LHsBinds id -- Used for dictionary or method bindings -type LHsBind id = Located (HsBind id) +type LHsBind id = LHsBindLR id id +type LHsBinds id = LHsBindsLR id 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 LHsBindsLR idL idR = Bag (LHsBindLR idL idR) +type LHsBindLR idL idR = Located (HsBindLR 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,[Id]) -- ^ 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 + var_inline :: Bool -- True <=> inline this binding regardless + -- (used for implication constraints only) } - | 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 - -- mixed up together; you can tell the dict bindings because - -- they are all VarBinds + | AbsBinds { -- Binds abstraction; TRANSLATION + abs_tvs :: [TyVar], + abs_ev_vars :: [EvVar], -- 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, TcSpecPrags)], -- (tvs, poly_id, mono_id, prags) + + abs_ev_binds :: TcEvBinds, -- Evidence bindings + abs_binds :: LHsBinds idL -- Typechecked user bindings } + + deriving (Data, Typeable) -- Consider (AbsBinds tvs ds [(ftvs, poly_f, mono_f) binds] -- -- Creates bindings for (polymorphic, overloaded) poly_f @@ -138,12 +176,12 @@ placeHolderNames :: NameSet 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 @@ -155,51 +193,51 @@ instance OutputableBndr id => Outputable (HsValBinds id) where 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 ------------ @@ -208,6 +246,13 @@ plusHsValBinds (ValBindsIn ds1 sigs1) (ValBindsIn ds2 sigs2) = ValBindsIn (ds1 `unionBags` ds2) (sigs1 ++ sigs2) plusHsValBinds (ValBindsOut ds1 sigs1) (ValBindsOut ds2 sigs2) = ValBindsOut (ds1 ++ ds2) (sigs1 ++ sigs2) + +getTypeSigNames :: HsValBinds a -> NameSet +-- Get the names that have a user type sig +getTypeSigNames (ValBindsIn {}) + = panic "getTypeSigNames" +getTypeSigNames (ValBindsOut _ sigs) + = mkNameSet [unLoc n | L _ (TypeSig n _) <- sigs] \end{code} What AbsBinds means @@ -235,36 +280,53 @@ So the desugarer tries to do a better job: 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 (FunBind { fun_id = fun, +ppr_monobind (PatBind { pat_lhs = pat, pat_rhs = grhss }) + = pprPatBind pat grhss +ppr_monobind (VarBind { var_id = var, var_rhs = rhs }) + = sep [pprBndr CaseBind var, nest 2 $ equals <+> pprExpr (unLoc rhs)] +ppr_monobind (FunBind { fun_id = fun, fun_infix = inf, + fun_co_fn = wrap, fun_matches = matches, - fun_tick = tick }) = - (case tick of - Nothing -> empty - Just t -> text "-- tick id = " <> ppr t - ) $$ pprFunBind (unLoc fun) matches - -- ToDo: print infix if appropriate - -ppr_monobind (AbsBinds { abs_tvs = tyvars, abs_dicts = dictvars, - abs_exports = exports, abs_binds = val_binds }) - = sep [ptext SLIT("AbsBinds"), - brackets (interpp'SP tyvars), - brackets (interpp'SP dictvars), - brackets (sep (punctuate comma (map ppr_exp exports)))] - $$ - nest 2 ( vcat [pprBndr LetBind x | (_,x,_,_) <- exports] - -- Print type signatures - $$ pprLHsBinds val_binds ) + fun_tick = tick }) + = pprTicks empty (case tick of + Nothing -> empty + Just t -> text "-- tick id = " <> ppr t) + $$ ifPprDebug (pprBndr LetBind (unLoc fun)) + $$ pprFunBind (unLoc fun) inf matches + $$ ifPprDebug (ppr wrap) + +ppr_monobind (AbsBinds { abs_tvs = tyvars, abs_ev_vars = dictvars + , abs_exports = exports, abs_binds = val_binds + , abs_ev_binds = ev_binds }) + = sep [ptext (sLit "AbsBinds"), + brackets (interpp'SP tyvars), + brackets (interpp'SP dictvars), + brackets (sep (punctuate comma (map ppr_exp exports)))] + $$ + nest 2 ( vcat [pprBndr LetBind x | (_,x,_,_) <- exports] + -- Print type signatures + $$ pprLHsBinds val_binds ) + $$ + ifPprDebug (ppr ev_binds) where ppr_exp (tvs, gbl, lcl, prags) - = vcat [ppr gbl <+> ptext SLIT("<=") <+> ppr tvs <+> ppr lcl, - nest 2 (vcat (map (pprPrag gbl) prags))] + = vcat [ppr gbl <+> ptext (sLit "<=") <+> ppr tvs <+> ppr lcl, + nest 2 (pprTcSpecPrags prags)] +\end{code} + + +\begin{code} +pprTicks :: SDoc -> SDoc -> SDoc +-- Print stuff about ticks only when -dppr-debug is on, to avoid +-- them appearing in error messages (from the desugarer); see Trac # 3263 +pprTicks pp_no_debug pp_when_debug + = getPprStyle (\ sty -> if debugStyle sty then pp_when_debug + else pp_no_debug) \end{code} %************************************************************************ @@ -277,11 +339,12 @@ ppr_monobind (AbsBinds { abs_tvs = tyvars, abs_dicts = dictvars, data HsIPBinds id = IPBinds [LIPBind id] - (DictBinds id) -- Only in typechecker output; binds + TcEvBinds -- Only in typechecker output; binds -- uses of the implicit parameters + deriving (Data, Typeable) isEmptyIPBinds :: HsIPBinds id -> Bool -isEmptyIPBinds (IPBinds is ds) = null is && isEmptyBag ds +isEmptyIPBinds (IPBinds is ds) = null is && isEmptyTcEvBinds ds type LIPBind id = Located (IPBind id) @@ -290,10 +353,11 @@ data IPBind id = IPBind (IPName id) (LHsExpr id) + deriving (Data, Typeable) instance (OutputableBndr id) => Outputable (HsIPBinds id) where ppr (IPBinds bs ds) = pprDeeperList vcat (map ppr bs) - $$ pprLHsBinds ds + $$ ifPprDebug (ppr ds) instance (OutputableBndr id) => Outputable (IPBind id) where ppr (IPBind id rhs) = pprBndr LetBind id <+> equals <+> pprExpr (unLoc rhs) @@ -313,63 +377,206 @@ instance (OutputableBndr id) => Outputable (IPBind id) where data HsWrapper = WpHole -- The identity coercion - | WpCompose HsWrapper HsWrapper -- (\a1..an. []) `WpCompose` (\x1..xn. []) - -- = (\a1..an \x1..xn. []) + | WpCompose HsWrapper HsWrapper + -- (wrap1 `WpCompse` wrap2)[e] = wrap1[ wrap2[ e ]] + -- + -- Hence (\a. []) `WpCompose` (\b. []) = (\a b. []) + -- But ([] a) `WpCompose` ([] b) = ([] b a) - | 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 - | 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 + -- Evidence abstraction and application + -- (both dictionaries and coercions) + | WpEvLam EvVar -- \d. [] the 'd' is an evidence variable + | WpEvApp EvTerm -- [] d the 'd' is evidence for a constraint - -- Non-empty bindings, so that the identity coercion - -- is always exactly WpHole - | WpLet (LHsBinds Id) -- let binds in [] - -- (would be nicer to be core bindings) + -- Type abstraction and application + | WpTyLam TyVar -- \a. [] the 'a' is a type variable (not coercion var) + | WpTyApp Type -- [] t the 't' is a type (not coercion) -instance Outputable HsWrapper where - 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) = it <+> ptext SLIT("`cast`") <+> pprParendType co -pprHsWrapper it (WpApp id) = it <+> ppr id -pprHsWrapper it (WpTyApp ty) = it <+> ptext SLIT("@") <+> pprParendType ty -pprHsWrapper it (WpLam id) = ptext SLIT("\\") <> pprBndr LambdaBind id <> dot <+> it -pprHsWrapper it (WpTyLam tv) = ptext SLIT("/\\") <> pprBndr LambdaBind tv <> dot <+> it -pprHsWrapper it (WpLet binds) = sep [ptext SLIT("let") <+> braces (ppr binds), it] + | WpLet TcEvBinds -- Non-empty (or possibly non-empty) evidence bindings, + -- so that the identity coercion is always exactly WpHole + deriving (Data, Typeable) + + +data TcEvBinds + = TcEvBinds -- Mutable evidence bindings + EvBindsVar -- Mutable because they are updated "later" + -- when an implication constraint is solved + | EvBinds -- Immutable after zonking + (Bag EvBind) + + deriving( Typeable ) + +data EvBindsVar = EvBindsVar (IORef EvBindMap) Unique + -- The Unique is only for debug printing + +----------------- +type EvBindMap = VarEnv EvBind + +emptyEvBindMap :: EvBindMap +emptyEvBindMap = emptyVarEnv + +extendEvBinds :: EvBindMap -> EvVar -> EvTerm -> EvBindMap +extendEvBinds bs v t = extendVarEnv bs v (EvBind v t) + +lookupEvBind :: EvBindMap -> EvVar -> Maybe EvBind +lookupEvBind = lookupVarEnv + +evBindMapBinds :: EvBindMap -> Bag EvBind +evBindMapBinds = foldVarEnv consBag emptyBag + +----------------- +instance Data TcEvBinds where + -- Placeholder; we can't travers into TcEvBinds + toConstr _ = abstractConstr "TcEvBinds" + gunfold _ _ = error "gunfold" + dataTypeOf _ = mkNoRepType "TcEvBinds" + +-- All evidence is bound by EvBinds; no side effects +data EvBind = EvBind EvVar EvTerm + +data EvTerm + = EvId EvId -- Term-level variable-to-variable bindings + -- (no coercion variables! they come via EvCoercion) + + | EvCoercion Coercion -- Coercion bindings + + | EvCast EvVar Coercion -- d |> co + + | EvDFunApp DFunId -- Dictionary instance application + [Type] [EvVar] + + | EvSuperClass DictId Int -- n'th superclass. Used for both equalities and + -- dictionaries, even though the former have no + -- selector Id. We count up from _0_ + + deriving( Data, Typeable) + +evVarTerm :: EvVar -> EvTerm +evVarTerm v | isCoVar v = EvCoercion (mkCoVarCo v) + | otherwise = EvId v +\end{code} + +Note [EvBinds/EvTerm] +~~~~~~~~~~~~~~~~~~~~~ +How evidence is created and updated. Bindings for dictionaries, +and coercions and implicit parameters are carried around in TcEvBinds +which during constraint generation and simplification is always of the +form (TcEvBinds ref). After constraint simplification is finished it +will be transformed to t an (EvBinds ev_bag). + +Evidence for coercions *SHOULD* be filled in using the TcEvBinds +However, all EvVars that correspond to *wanted* coercion terms in +an EvBind must be mutable variables so that they can be readily +inlined (by zonking) after constraint simplification is finished. + +Conclusion: a new wanted coercion variable should be made mutable. +[Notice though that evidence variables that bind coercion terms + from super classes will be "given" and hence rigid] + + +\begin{code} +emptyTcEvBinds :: TcEvBinds +emptyTcEvBinds = EvBinds emptyBag + +isEmptyTcEvBinds :: TcEvBinds -> Bool +isEmptyTcEvBinds (EvBinds b) = isEmptyBag b +isEmptyTcEvBinds (TcEvBinds {}) = panic "isEmptyTcEvBinds" + (<.>) :: HsWrapper -> HsWrapper -> HsWrapper WpHole <.> c = c c <.> WpHole = c c1 <.> c2 = c1 `WpCompose` c2 mkWpTyApps :: [Type] -> HsWrapper -mkWpTyApps tys = mk_co_fn WpTyApp (reverse tys) +mkWpTyApps tys = mk_co_app_fn WpTyApp tys + +mkWpEvApps :: [EvTerm] -> HsWrapper +mkWpEvApps args = mk_co_app_fn WpEvApp args -mkWpApps :: [Id] -> HsWrapper -mkWpApps ids = mk_co_fn WpApp (reverse ids) +mkWpEvVarApps :: [EvVar] -> HsWrapper +mkWpEvVarApps vs = mkWpEvApps (map evVarTerm vs) mkWpTyLams :: [TyVar] -> HsWrapper -mkWpTyLams ids = mk_co_fn WpTyLam ids +mkWpTyLams ids = mk_co_lam_fn WpTyLam ids -mkWpLams :: [Id] -> HsWrapper -mkWpLams ids = mk_co_fn WpLam ids +mkWpLams :: [Var] -> HsWrapper +mkWpLams ids = mk_co_lam_fn WpEvLam ids -mk_co_fn :: (a -> HsWrapper) -> [a] -> HsWrapper -mk_co_fn f as = foldr (WpCompose . f) WpHole as +mkWpLet :: TcEvBinds -> HsWrapper +-- This no-op is a quite a common case +mkWpLet (EvBinds b) | isEmptyBag b = WpHole +mkWpLet ev_binds = WpLet ev_binds + +mk_co_lam_fn :: (a -> HsWrapper) -> [a] -> HsWrapper +mk_co_lam_fn f as = foldr (\x wrap -> f x `WpCompose` wrap) WpHole as + +mk_co_app_fn :: (a -> HsWrapper) -> [a] -> HsWrapper +-- For applications, the *first* argument must +-- come *last* in the composition sequence +mk_co_app_fn f as = foldr (\x wrap -> wrap `WpCompose` f x) WpHole as idHsWrapper :: HsWrapper idHsWrapper = WpHole isIdHsWrapper :: HsWrapper -> Bool isIdHsWrapper WpHole = True -isIdHsWrapper other = False +isIdHsWrapper _ = False \end{code} +Pretty printing + +\begin{code} +instance Outputable HsWrapper where + ppr co_fn = pprHsWrapper (ptext (sLit "<>")) co_fn + +pprHsWrapper :: SDoc -> HsWrapper -> SDoc +-- In debug mode, print the wrapper +-- otherwise just print what's inside +pprHsWrapper doc wrap + = getPprStyle (\ s -> if debugStyle s then (help (add_parens doc) wrap False) else doc) + where + help :: (Bool -> SDoc) -> HsWrapper -> Bool -> SDoc + -- True <=> appears in function application position + -- False <=> appears as body of let or lambda + help it WpHole = it + help it (WpCompose f1 f2) = help (help it f2) f1 + help it (WpCast co) = add_parens $ sep [it False, nest 2 (ptext (sLit "|>") + <+> pprParendCo co)] + help it (WpEvApp id) = no_parens $ sep [it True, nest 2 (ppr id)] + help it (WpTyApp ty) = no_parens $ sep [it True, ptext (sLit "@") <+> pprParendType ty] + help it (WpEvLam id) = add_parens $ sep [ ptext (sLit "\\") <> pp_bndr id, it False] + help it (WpTyLam tv) = add_parens $ sep [ptext (sLit "/\\") <> pp_bndr tv, it False] + help it (WpLet binds) = add_parens $ sep [ptext (sLit "let") <+> braces (ppr binds), it False] + + pp_bndr v = pprBndr LambdaBind v <> dot + + add_parens, no_parens :: SDoc -> Bool -> SDoc + add_parens d True = parens d + add_parens d False = d + no_parens d _ = d + +instance Outputable TcEvBinds where + ppr (TcEvBinds v) = ppr v + ppr (EvBinds bs) = ptext (sLit "EvBinds") <> braces (ppr bs) + +instance Outputable EvBindsVar where + ppr (EvBindsVar _ u) = ptext (sLit "EvBindsVar") <> angleBrackets (ppr u) + +instance Outputable EvBind where + ppr (EvBind v e) = ppr v <+> equals <+> ppr e + +instance Outputable EvTerm where + ppr (EvId v) = ppr v + ppr (EvCast v co) = ppr v <+> (ptext (sLit "`cast`")) <+> pprParendCo co + ppr (EvCoercion co) = ptext (sLit "CO") <+> ppr co + ppr (EvSuperClass d n) = ptext (sLit "sc") <> parens (ppr (d,n)) + ppr (EvDFunApp df tys ts) = ppr df <+> sep [ char '@' <> ppr tys, ppr ts ] +\end{code} %************************************************************************ %* * @@ -388,131 +595,162 @@ type LSig name = Located (Sig name) data Sig name -- Signatures and pragmas = -- An ordinary type signature -- f :: Num a => a -> a - TypeSig (Located name) -- A bog-std type signature - (LHsType name) + TypeSig (Located name) (LHsType name) + + -- A type signature for a default method inside a class + -- default eq :: (Representable0 a, GEq (Rep0 a)) => a -> a -> Bool + | GenericSig (Located name) (LHsType name) + + -- A type signature in generated code, notably the code + -- generated for record selectors. We simply record + -- the desired Id itself, replete with its name, type + -- and IdDetails. Otherwise it's just like a type + -- signature: there should be an accompanying binding + | IdSig Id -- An ordinary fixity declaration -- infixl *** 8 - | FixSig (FixitySig name) -- Fixity declaration + | FixSig (FixitySig name) -- An inline pragma -- {#- INLINE f #-} | InlineSig (Located name) -- Function name - InlineSpec + InlinePragma -- Never defaultInlinePragma -- A specialisation pragma -- {-# SPECIALISE f :: Int -> Int #-} | SpecSig (Located name) -- Specialise a function or datatype ... (LHsType name) -- ... to these types - InlineSpec + InlinePragma -- The pragma on SPECIALISE_INLINE form + -- If it's just defaultInlinePragma, then we said + -- SPECIALISE, not SPECIALISE_INLINE - -- A specialisation pragma for instance declarations only - -- {-# SPECIALISE instance Eq [Int] #-} - | SpecInstSig (LHsType name) -- (Class tys); should be a specialisation of the - -- current instance decl + -- A specialisation pragma for instance declarations only + -- {-# SPECIALISE instance Eq [Int] #-} + | SpecInstSig (LHsType name) -- (Class tys); should be a specialisation of the + -- current instance decl + deriving (Data, Typeable) type LFixitySig name = Located (FixitySig name) data FixitySig name = FixitySig (Located name) Fixity + deriving (Data, Typeable) + +-- TsSpecPrags conveys pragmas from the type checker to the desugarer +data TcSpecPrags + = IsDefaultMethod -- Super-specialised: a default method should + -- be macro-expanded at every call site + | SpecPrags [LTcSpecPrag] + deriving (Data, Typeable) + +type LTcSpecPrag = Located TcSpecPrag + +data TcSpecPrag + = SpecPrag + Id -- The Id to be specialised + HsWrapper -- An wrapper, that specialises the polymorphic function + InlinePragma -- Inlining spec for the specialised function + deriving (Data, Typeable) + +noSpecPrags :: TcSpecPrags +noSpecPrags = SpecPrags [] + +hasSpecPrags :: TcSpecPrags -> Bool +hasSpecPrags (SpecPrags ps) = not (null ps) +hasSpecPrags IsDefaultMethod = False + +isDefaultMethod :: TcSpecPrags -> Bool +isDefaultMethod IsDefaultMethod = True +isDefaultMethod (SpecPrags {}) = False --- A Prag conveys pragmas from the type checker to the desugarer -type LPrag = Located Prag -data Prag - = InlinePrag - InlineSpec - - | 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 (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 _ (TypeSig _ _)) = True -okHsBootSig (L _ (FixSig _)) = True -okHsBootSig sig = False +okBindSig :: Sig a -> Bool +okBindSig _ = True -okClsDclSig :: LSig Name -> Bool -okClsDclSig (L _ (SpecInstSig _)) = False -okClsDclSig sig = True -- All others OK +okHsBootSig :: Sig a -> Bool +okHsBootSig (TypeSig _ _) = True +okHsBootSig (GenericSig _ _) = False +okHsBootSig (FixSig _) = True +okHsBootSig _ = False -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 +okClsDclSig :: Sig a -> Bool +okClsDclSig (SpecInstSig _) = False +okClsDclSig _ = True -- All others OK -sigForThisGroup :: NameSet -> LSig Name -> Bool -sigForThisGroup ns sig - = case sigName sig of - Nothing -> False - Just n -> n `elemNameSet` ns +okInstDclSig :: Sig a -> Bool +okInstDclSig (TypeSig _ _) = False +okInstDclSig (GenericSig _ _) = False +okInstDclSig (FixSig _) = False +okInstDclSig _ = True sigName :: LSig name -> Maybe name +-- Used only in Haddock sigName (L _ sig) = sigNameNoLoc sig sigNameNoLoc :: Sig name -> Maybe name +-- Used only in Haddock sigNameNoLoc (TypeSig n _) = Just (unLoc n) 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 isFixityLSig _ = False -isVanillaLSig :: LSig name -> Bool +isVanillaLSig :: LSig name -> Bool -- User type signatures +-- A badly-named function, but it's part of the GHCi (used +-- by Haddock) so I don't want to change it gratuitously. isVanillaLSig (L _(TypeSig {})) = True -isVanillaLSig sig = False +isVanillaLSig _ = False + +isTypeLSig :: LSig name -> Bool -- Type signatures +isTypeLSig (L _(TypeSig {})) = True +isTypeLSig (L _(GenericSig {})) = True +isTypeLSig (L _(IdSig {})) = True +isTypeLSig _ = 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 (GenericSig {}) = ptext (sLit "default type signature") +hsSigDoc (IdSig {}) = ptext (sLit "id 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 _ (IdSig n1)) (L _ (IdSig n2)) = n1 == 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 _ (GenericSig n1 _)) (L _ (GenericSig n2 _)) = 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 @@ -524,25 +762,34 @@ instance (OutputableBndr name) => Outputable (Sig name) where ppr sig = ppr_sig sig ppr_sig :: OutputableBndr name => Sig name -> SDoc -ppr_sig (TypeSig var ty) = pprVarSig (unLoc var) ty +ppr_sig (TypeSig var ty) = pprVarSig (unLoc var) (ppr ty) +ppr_sig (GenericSig var ty) = ptext (sLit "default") <+> pprVarSig (unLoc var) (ppr ty) +ppr_sig (IdSig id) = pprVarSig id (ppr (varType id)) ppr_sig (FixSig fix_sig) = ppr fix_sig -ppr_sig (SpecSig var ty inl) = pragBrackets (pprSpec var ty inl) +ppr_sig (SpecSig var ty inl) = pragBrackets (pprSpec var (ppr 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) => id -> SDoc -> SDoc +pprVarSig var pp_ty = sep [ppr var <+> dcolon, nest 2 pp_ty] -pprVarSig :: (Outputable id, Outputable ty) => id -> ty -> SDoc -pprVarSig var ty = sep [ppr var <+> dcolon, nest 2 (ppr ty)] +pprSpec :: (Outputable id) => id -> SDoc -> InlinePragma -> SDoc +pprSpec var pp_ty inl = ptext (sLit "SPECIALIZE") <+> pp_inl <+> pprVarSig var pp_ty + where + pp_inl | isDefaultInlinePragma inl = empty + | otherwise = ppr inl -pprSpec :: (Outputable id, Outputable ty) => id -> ty -> InlineSpec -> SDoc -pprSpec var ty inl = sep [ptext SLIT("SPECIALIZE") <+> ppr inl <+> pprVarSig var ty] +pprTcSpecPrags :: TcSpecPrags -> SDoc +pprTcSpecPrags IsDefaultMethod = ptext (sLit "") +pprTcSpecPrags (SpecPrags ps) = vcat (map (ppr . unLoc) ps) -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 +instance Outputable TcSpecPrag where + ppr (SpecPrag var _ inl) = pprSpec var (ptext (sLit "")) inl \end{code} +