{- (c) The University of Glasgow 2006 (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 -} {-# LANGUAGE CPP #-} {-# LANGUAGE DeriveDataTypeable, DeriveFunctor, DeriveFoldable, DeriveTraversable #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE UndecidableInstances #-} -- Note [Pass sensitive types] -- in module PlaceHolder {-# LANGUAGE ConstraintKinds #-} {-# LANGUAGE FlexibleInstances #-} -- | Abstract syntax of global declarations. -- -- Definitions for: @SynDecl@ and @ConDecl@, @ClassDecl@, -- @InstDecl@, @DefaultDecl@ and @ForeignDecl@. module HsDecls ( -- * Toplevel declarations HsDecl(..), LHsDecl, HsDataDefn(..), HsDeriving, -- ** Class or type declarations TyClDecl(..), LTyClDecl, TyClGroup(..), tyClGroupConcat, mkTyClGroup, isClassDecl, isDataDecl, isSynDecl, tcdName, isFamilyDecl, isTypeFamilyDecl, isDataFamilyDecl, isOpenTypeFamilyInfo, isClosedTypeFamilyInfo, tyFamInstDeclName, tyFamInstDeclLName, countTyClDecls, pprTyClDeclFlavour, tyClDeclLName, tyClDeclTyVars, hsDeclHasCusk, famDeclHasCusk, FamilyDecl(..), LFamilyDecl, -- ** Instance declarations InstDecl(..), LInstDecl, NewOrData(..), FamilyInfo(..), TyFamInstDecl(..), LTyFamInstDecl, instDeclDataFamInsts, DataFamInstDecl(..), LDataFamInstDecl, pprDataFamInstFlavour, TyFamEqn(..), TyFamInstEqn, LTyFamInstEqn, TyFamDefltEqn, LTyFamDefltEqn, HsTyPats, LClsInstDecl, ClsInstDecl(..), -- ** Standalone deriving declarations DerivDecl(..), LDerivDecl, -- ** @RULE@ declarations LRuleDecls,RuleDecls(..),RuleDecl(..), LRuleDecl, RuleBndr(..),LRuleBndr, collectRuleBndrSigTys, flattenRuleDecls, pprFullRuleName, -- ** @VECTORISE@ declarations VectDecl(..), LVectDecl, lvectDeclName, lvectInstDecl, -- ** @default@ declarations DefaultDecl(..), LDefaultDecl, -- ** Template haskell declaration splice SpliceExplicitFlag(..), SpliceDecl(..), LSpliceDecl, -- ** Foreign function interface declarations ForeignDecl(..), LForeignDecl, ForeignImport(..), ForeignExport(..), noForeignImportCoercionYet, noForeignExportCoercionYet, CImportSpec(..), -- ** Data-constructor declarations ConDecl(..), LConDecl, HsConDeclDetails, hsConDeclArgTys, getConNames, getConDetails, gadtDeclDetails, -- ** Document comments DocDecl(..), LDocDecl, docDeclDoc, -- ** Deprecations WarnDecl(..), LWarnDecl, WarnDecls(..), LWarnDecls, -- ** Annotations AnnDecl(..), LAnnDecl, AnnProvenance(..), annProvenanceName_maybe, -- ** Role annotations RoleAnnotDecl(..), LRoleAnnotDecl, roleAnnotDeclName, -- ** Injective type families FamilyResultSig(..), LFamilyResultSig, InjectivityAnn(..), LInjectivityAnn, resultVariableName, -- * Grouping HsGroup(..), emptyRdrGroup, emptyRnGroup, appendGroups ) where -- friends: import {-# SOURCE #-} HsExpr( LHsExpr, HsExpr, HsSplice, pprExpr, pprSplice ) -- Because Expr imports Decls via HsBracket import HsBinds import HsTypes import HsDoc import TyCon import Name import BasicTypes import Coercion import ForeignCall import PlaceHolder ( PostTc,PostRn,PlaceHolder(..),DataId ) import NameSet -- others: import InstEnv import Class import Outputable import Util import SrcLoc import FastString import Bag import Data.Maybe ( fromMaybe ) import Data.Data hiding (TyCon,Fixity) #if __GLASGOW_HASKELL__ < 709 import Data.Foldable ( Foldable ) import Data.Traversable ( Traversable ) #endif {- ************************************************************************ * * \subsection[HsDecl]{Declarations} * * ************************************************************************ -} type LHsDecl id = Located (HsDecl id) -- ^ When in a list this may have -- -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnSemi' -- -- For details on above see note [Api annotations] in ApiAnnotation -- | A Haskell Declaration data HsDecl id = TyClD (TyClDecl id) -- ^ A type or class declaration. | InstD (InstDecl id) -- ^ An instance declaration. | DerivD (DerivDecl id) | ValD (HsBind id) | SigD (Sig id) | DefD (DefaultDecl id) | ForD (ForeignDecl id) | WarningD (WarnDecls id) | AnnD (AnnDecl id) | RuleD (RuleDecls id) | VectD (VectDecl id) | SpliceD (SpliceDecl id) -- Includes quasi-quotes | DocD (DocDecl) | RoleAnnotD (RoleAnnotDecl id) deriving (Typeable) deriving instance (DataId id) => Data (HsDecl id) -- NB: all top-level fixity decls are contained EITHER -- EITHER SigDs -- OR in the ClassDecls in TyClDs -- -- The former covers -- a) data constructors -- b) class methods (but they can be also done in the -- signatures of class decls) -- c) imported functions (that have an IfacSig) -- d) top level decls -- -- The latter is for class methods only -- | A 'HsDecl' is categorised into a 'HsGroup' before being -- fed to the renamer. data HsGroup id = HsGroup { hs_valds :: HsValBinds id, hs_splcds :: [LSpliceDecl id], hs_tyclds :: [TyClGroup id], -- A list of mutually-recursive groups -- No family-instances here; they are in hs_instds -- Parser generates a singleton list; -- renamer does dependency analysis hs_instds :: [LInstDecl id], -- Both class and family instance declarations in here hs_derivds :: [LDerivDecl id], hs_fixds :: [LFixitySig id], -- Snaffled out of both top-level fixity signatures, -- and those in class declarations hs_defds :: [LDefaultDecl id], hs_fords :: [LForeignDecl id], hs_warnds :: [LWarnDecls id], hs_annds :: [LAnnDecl id], hs_ruleds :: [LRuleDecls id], hs_vects :: [LVectDecl id], hs_docs :: [LDocDecl] } deriving (Typeable) deriving instance (DataId id) => Data (HsGroup id) emptyGroup, emptyRdrGroup, emptyRnGroup :: HsGroup a emptyRdrGroup = emptyGroup { hs_valds = emptyValBindsIn } emptyRnGroup = emptyGroup { hs_valds = emptyValBindsOut } emptyGroup = HsGroup { hs_tyclds = [], hs_instds = [], hs_derivds = [], hs_fixds = [], hs_defds = [], hs_annds = [], hs_fords = [], hs_warnds = [], hs_ruleds = [], hs_vects = [], hs_valds = error "emptyGroup hs_valds: Can't happen", hs_splcds = [], hs_docs = [] } appendGroups :: HsGroup a -> HsGroup a -> HsGroup a appendGroups HsGroup { hs_valds = val_groups1, hs_splcds = spliceds1, hs_tyclds = tyclds1, hs_instds = instds1, hs_derivds = derivds1, hs_fixds = fixds1, hs_defds = defds1, hs_annds = annds1, hs_fords = fords1, hs_warnds = warnds1, hs_ruleds = rulds1, hs_vects = vects1, hs_docs = docs1 } HsGroup { hs_valds = val_groups2, hs_splcds = spliceds2, hs_tyclds = tyclds2, hs_instds = instds2, hs_derivds = derivds2, hs_fixds = fixds2, hs_defds = defds2, hs_annds = annds2, hs_fords = fords2, hs_warnds = warnds2, hs_ruleds = rulds2, hs_vects = vects2, hs_docs = docs2 } = HsGroup { hs_valds = val_groups1 `plusHsValBinds` val_groups2, hs_splcds = spliceds1 ++ spliceds2, hs_tyclds = tyclds1 ++ tyclds2, hs_instds = instds1 ++ instds2, hs_derivds = derivds1 ++ derivds2, hs_fixds = fixds1 ++ fixds2, hs_annds = annds1 ++ annds2, hs_defds = defds1 ++ defds2, hs_fords = fords1 ++ fords2, hs_warnds = warnds1 ++ warnds2, hs_ruleds = rulds1 ++ rulds2, hs_vects = vects1 ++ vects2, hs_docs = docs1 ++ docs2 } instance OutputableBndr name => Outputable (HsDecl name) where ppr (TyClD dcl) = ppr dcl ppr (ValD binds) = ppr binds ppr (DefD def) = ppr def ppr (InstD inst) = ppr inst ppr (DerivD deriv) = ppr deriv ppr (ForD fd) = ppr fd ppr (SigD sd) = ppr sd ppr (RuleD rd) = ppr rd ppr (VectD vect) = ppr vect ppr (WarningD wd) = ppr wd ppr (AnnD ad) = ppr ad ppr (SpliceD dd) = ppr dd ppr (DocD doc) = ppr doc ppr (RoleAnnotD ra) = ppr ra instance OutputableBndr name => Outputable (HsGroup name) where ppr (HsGroup { hs_valds = val_decls, hs_tyclds = tycl_decls, hs_instds = inst_decls, hs_derivds = deriv_decls, hs_fixds = fix_decls, hs_warnds = deprec_decls, hs_annds = ann_decls, hs_fords = foreign_decls, hs_defds = default_decls, hs_ruleds = rule_decls, hs_vects = vect_decls }) = vcat_mb empty [ppr_ds fix_decls, ppr_ds default_decls, ppr_ds deprec_decls, ppr_ds ann_decls, ppr_ds rule_decls, ppr_ds vect_decls, if isEmptyValBinds val_decls then Nothing else Just (ppr val_decls), ppr_ds (tyClGroupConcat tycl_decls), ppr_ds inst_decls, ppr_ds deriv_decls, ppr_ds foreign_decls] where ppr_ds :: Outputable a => [a] -> Maybe SDoc ppr_ds [] = Nothing ppr_ds ds = Just (vcat (map ppr ds)) vcat_mb :: SDoc -> [Maybe SDoc] -> SDoc -- Concatenate vertically with white-space between non-blanks vcat_mb _ [] = empty vcat_mb gap (Nothing : ds) = vcat_mb gap ds vcat_mb gap (Just d : ds) = gap $$ d $$ vcat_mb blankLine ds data SpliceExplicitFlag = ExplicitSplice | -- <=> $(f x y) ImplicitSplice -- <=> f x y, i.e. a naked top level expression deriving (Data, Typeable) type LSpliceDecl name = Located (SpliceDecl name) data SpliceDecl id = SpliceDecl -- Top level splice (Located (HsSplice id)) SpliceExplicitFlag deriving (Typeable) deriving instance (DataId id) => Data (SpliceDecl id) instance OutputableBndr name => Outputable (SpliceDecl name) where ppr (SpliceDecl (L _ e) _) = pprSplice e {- ************************************************************************ * * \subsection[SynDecl]{@data@, @newtype@ or @type@ (synonym) type declaration} * * ************************************************************************ -------------------------------- THE NAMING STORY -------------------------------- Here is the story about the implicit names that go with type, class, and instance decls. It's a bit tricky, so pay attention! "Implicit" (or "system") binders ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Each data type decl defines a worker name for each constructor to-T and from-T convertors Each class decl defines a tycon for the class a data constructor for that tycon the worker for that constructor a selector for each superclass All have occurrence names that are derived uniquely from their parent declaration. None of these get separate definitions in an interface file; they are fully defined by the data or class decl. But they may *occur* in interface files, of course. Any such occurrence must haul in the relevant type or class decl. Plan of attack: - Ensure they "point to" the parent data/class decl when loading that decl from an interface file (See RnHiFiles.getSysBinders) - When typechecking the decl, we build the implicit TyCons and Ids. When doing so we look them up in the name cache (RnEnv.lookupSysName), to ensure correct module and provenance is set These are the two places that we have to conjure up the magic derived names. (The actual magic is in OccName.mkWorkerOcc, etc.) Default methods ~~~~~~~~~~~~~~~ - Occurrence name is derived uniquely from the method name E.g. $dmmax - If there is a default method name at all, it's recorded in the ClassOpSig (in HsBinds), in the DefMethInfo field. (DefMethInfo is defined in Class.hs) Source-code class decls and interface-code class decls are treated subtly differently, which has given me a great deal of confusion over the years. Here's the deal. (We distinguish the two cases because source-code decls have (Just binds) in the tcdMeths field, whereas interface decls have Nothing. In *source-code* class declarations: - When parsing, every ClassOpSig gets a DefMeth with a suitable RdrName This is done by RdrHsSyn.mkClassOpSigDM - The renamer renames it to a Name - During typechecking, we generate a binding for each $dm for which there's a programmer-supplied default method: class Foo a where op1 :: op2 :: op1 = ... We generate a binding for $dmop1 but not for $dmop2. The Class for Foo has a Nothing for op2 and a Just ($dm_op1, VanillaDM) for op1. The Name for $dmop2 is simply discarded. In *interface-file* class declarations: - When parsing, we see if there's an explicit programmer-supplied default method because there's an '=' sign to indicate it: class Foo a where op1 = :: -- NB the '=' op2 :: We use this info to generate a DefMeth with a suitable RdrName for op1, and a NoDefMeth for op2 - The interface file has a separate definition for $dmop1, with unfolding etc. - The renamer renames it to a Name. - The renamer treats $dmop1 as a free variable of the declaration, so that the binding for $dmop1 will be sucked in. (See RnHsSyn.tyClDeclFVs) This doesn't happen for source code class decls, because they *bind* the default method. Dictionary functions ~~~~~~~~~~~~~~~~~~~~ Each instance declaration gives rise to one dictionary function binding. The type checker makes up new source-code instance declarations (e.g. from 'deriving' or generic default methods --- see TcInstDcls.tcInstDecls1). So we can't generate the names for dictionary functions in advance (we don't know how many we need). On the other hand for interface-file instance declarations, the decl specifies the name of the dictionary function, and it has a binding elsewhere in the interface file: instance {Eq Int} = dEqInt dEqInt :: {Eq Int} So again we treat source code and interface file code slightly differently. Source code: - Source code instance decls have a Nothing in the (Maybe name) field (see data InstDecl below) - The typechecker makes up a Local name for the dict fun for any source-code instance decl, whether it comes from a source-code instance decl, or whether the instance decl is derived from some other construct (e.g. 'deriving'). - The occurrence name it chooses is derived from the instance decl (just for documentation really) --- e.g. dNumInt. Two dict funs may share a common occurrence name, but will have different uniques. E.g. instance Foo [Int] where ... instance Foo [Bool] where ... These might both be dFooList - The CoreTidy phase externalises the name, and ensures the occurrence name is unique (this isn't special to dict funs). So we'd get dFooList and dFooList1. - We can take this relaxed approach (changing the occurrence name later) because dict fun Ids are not captured in a TyCon or Class (unlike default methods, say). Instead, they are kept separately in the InstEnv. This makes it easy to adjust them after compiling a module. (Once we've finished compiling that module, they don't change any more.) Interface file code: - The instance decl gives the dict fun name, so the InstDecl has a (Just name) in the (Maybe name) field. - RnHsSyn.instDeclFVs treats the dict fun name as free in the decl, so that we suck in the dfun binding -} type LTyClDecl name = Located (TyClDecl name) -- | A type or class declaration. data TyClDecl name = -- | @type/data family T :: *->*@ -- -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnType', -- 'ApiAnnotation.AnnData', -- 'ApiAnnotation.AnnFamily','ApiAnnotation.AnnDcolon', -- 'ApiAnnotation.AnnWhere','ApiAnnotation.AnnOpenP', -- 'ApiAnnotation.AnnDcolon','ApiAnnotation.AnnCloseP', -- 'ApiAnnotation.AnnEqual','ApiAnnotation.AnnRarrow', -- 'ApiAnnotation.AnnVbar' -- For details on above see note [Api annotations] in ApiAnnotation FamDecl { tcdFam :: FamilyDecl name } | -- | @type@ declaration -- -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnType', -- 'ApiAnnotation.AnnEqual', -- For details on above see note [Api annotations] in ApiAnnotation SynDecl { tcdLName :: Located name -- ^ Type constructor , tcdTyVars :: LHsQTyVars name -- ^ Type variables; for an associated type -- these include outer binders , tcdRhs :: LHsType name -- ^ RHS of type declaration , tcdFVs :: PostRn name NameSet } | -- | @data@ declaration -- -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnData', -- 'ApiAnnotation.AnnFamily', -- 'ApiAnnotation.AnnNewType', -- 'ApiAnnotation.AnnNewType','ApiAnnotation.AnnDcolon' -- 'ApiAnnotation.AnnWhere', -- For details on above see note [Api annotations] in ApiAnnotation DataDecl { tcdLName :: Located name -- ^ Type constructor , tcdTyVars :: LHsQTyVars name -- ^ Type variables; for an associated type -- these include outer binders -- Eg class T a where -- type F a :: * -- type F a = a -> a -- Here the type decl for 'f' includes 'a' -- in its tcdTyVars , tcdDataDefn :: HsDataDefn name , tcdFVs :: PostRn name NameSet } | ClassDecl { tcdCtxt :: LHsContext name, -- ^ Context... tcdLName :: Located name, -- ^ Name of the class tcdTyVars :: LHsQTyVars name, -- ^ Class type variables tcdFDs :: [Located (FunDep (Located name))], -- ^ Functional deps tcdSigs :: [LSig name], -- ^ Methods' signatures tcdMeths :: LHsBinds name, -- ^ Default methods tcdATs :: [LFamilyDecl name], -- ^ Associated types; tcdATDefs :: [LTyFamDefltEqn name], -- ^ Associated type defaults tcdDocs :: [LDocDecl], -- ^ Haddock docs tcdFVs :: PostRn name NameSet } -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnClass', -- 'ApiAnnotation.AnnWhere','ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnClose' -- - The tcdFDs will have 'ApiAnnotation.AnnVbar', -- 'ApiAnnotation.AnnComma' -- 'ApiAnnotation.AnnRarrow' -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId id) => Data (TyClDecl id) -- This is used in TcTyClsDecls to represent -- strongly connected components of decls -- No familiy instances in here -- The role annotations must be grouped with their decls for the -- type-checker to infer roles correctly data TyClGroup name = TyClGroup { group_tyclds :: [LTyClDecl name] , group_roles :: [LRoleAnnotDecl name] } deriving (Typeable) deriving instance (DataId id) => Data (TyClGroup id) tyClGroupConcat :: [TyClGroup name] -> [LTyClDecl name] tyClGroupConcat = concatMap group_tyclds mkTyClGroup :: [LTyClDecl name] -> TyClGroup name mkTyClGroup decls = TyClGroup { group_tyclds = decls, group_roles = [] } -- Simple classifiers for TyClDecl -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- | @True@ <=> argument is a @data@\/@newtype@ -- declaration. isDataDecl :: TyClDecl name -> Bool isDataDecl (DataDecl {}) = True isDataDecl _other = False -- | type or type instance declaration isSynDecl :: TyClDecl name -> Bool isSynDecl (SynDecl {}) = True isSynDecl _other = False -- | type class isClassDecl :: TyClDecl name -> Bool isClassDecl (ClassDecl {}) = True isClassDecl _ = False -- | type/data family declaration isFamilyDecl :: TyClDecl name -> Bool isFamilyDecl (FamDecl {}) = True isFamilyDecl _other = False -- | type family declaration isTypeFamilyDecl :: TyClDecl name -> Bool isTypeFamilyDecl (FamDecl (FamilyDecl { fdInfo = info })) = case info of OpenTypeFamily -> True ClosedTypeFamily {} -> True _ -> False isTypeFamilyDecl _ = False -- | open type family info isOpenTypeFamilyInfo :: FamilyInfo name -> Bool isOpenTypeFamilyInfo OpenTypeFamily = True isOpenTypeFamilyInfo _ = False -- | closed type family info isClosedTypeFamilyInfo :: FamilyInfo name -> Bool isClosedTypeFamilyInfo (ClosedTypeFamily {}) = True isClosedTypeFamilyInfo _ = False -- | data family declaration isDataFamilyDecl :: TyClDecl name -> Bool isDataFamilyDecl (FamDecl (FamilyDecl { fdInfo = DataFamily })) = True isDataFamilyDecl _other = False -- Dealing with names tyFamInstDeclName :: TyFamInstDecl name -> name tyFamInstDeclName = unLoc . tyFamInstDeclLName tyFamInstDeclLName :: TyFamInstDecl name -> Located name tyFamInstDeclLName (TyFamInstDecl { tfid_eqn = (L _ (TyFamEqn { tfe_tycon = ln })) }) = ln tyClDeclLName :: TyClDecl name -> Located name tyClDeclLName (FamDecl { tcdFam = FamilyDecl { fdLName = ln } }) = ln tyClDeclLName decl = tcdLName decl tcdName :: TyClDecl name -> name tcdName = unLoc . tyClDeclLName tyClDeclTyVars :: TyClDecl name -> LHsQTyVars name tyClDeclTyVars (FamDecl { tcdFam = FamilyDecl { fdTyVars = tvs } }) = tvs tyClDeclTyVars d = tcdTyVars d countTyClDecls :: [TyClDecl name] -> (Int, Int, Int, Int, Int) -- class, synonym decls, data, newtype, family decls countTyClDecls decls = (count isClassDecl decls, count isSynDecl decls, -- excluding... count isDataTy decls, -- ...family... count isNewTy decls, -- ...instances count isFamilyDecl decls) where isDataTy DataDecl{ tcdDataDefn = HsDataDefn { dd_ND = DataType } } = True isDataTy _ = False isNewTy DataDecl{ tcdDataDefn = HsDataDefn { dd_ND = NewType } } = True isNewTy _ = False -- | Does this declaration have a complete, user-supplied kind signature? -- See Note [Complete user-supplied kind signatures] hsDeclHasCusk :: TyClDecl Name -> Bool hsDeclHasCusk (FamDecl { tcdFam = fam_decl }) = famDeclHasCusk fam_decl hsDeclHasCusk (SynDecl { tcdTyVars = tyvars, tcdRhs = rhs }) = hsTvbAllKinded tyvars && rhs_annotated rhs where rhs_annotated (L _ ty) = case ty of HsParTy lty -> rhs_annotated lty HsKindSig {} -> True _ -> False hsDeclHasCusk (DataDecl { tcdTyVars = tyvars }) = hsTvbAllKinded tyvars hsDeclHasCusk (ClassDecl { tcdTyVars = tyvars }) = hsTvbAllKinded tyvars -- Pretty-printing TyClDecl -- ~~~~~~~~~~~~~~~~~~~~~~~~ instance OutputableBndr name => Outputable (TyClDecl name) where ppr (FamDecl { tcdFam = decl }) = ppr decl ppr (SynDecl { tcdLName = ltycon, tcdTyVars = tyvars, tcdRhs = rhs }) = hang (ptext (sLit "type") <+> pp_vanilla_decl_head ltycon tyvars [] <+> equals) 4 (ppr rhs) ppr (DataDecl { tcdLName = ltycon, tcdTyVars = tyvars, tcdDataDefn = defn }) = pp_data_defn (pp_vanilla_decl_head ltycon tyvars) defn ppr (ClassDecl {tcdCtxt = context, tcdLName = lclas, tcdTyVars = tyvars, tcdFDs = fds, tcdSigs = sigs, tcdMeths = methods, tcdATs = ats, tcdATDefs = at_defs}) | null sigs && isEmptyBag methods && null ats && null at_defs -- No "where" part = top_matter | otherwise -- Laid out = vcat [ top_matter <+> ptext (sLit "where") , nest 2 $ pprDeclList (map (pprFamilyDecl NotTopLevel . unLoc) ats ++ map ppr_fam_deflt_eqn at_defs ++ pprLHsBindsForUser methods sigs) ] where top_matter = ptext (sLit "class") <+> pp_vanilla_decl_head lclas tyvars (unLoc context) <+> pprFundeps (map unLoc fds) instance OutputableBndr name => Outputable (TyClGroup name) where ppr (TyClGroup { group_tyclds = tyclds, group_roles = roles }) = ppr tyclds $$ ppr roles pp_vanilla_decl_head :: OutputableBndr name => Located name -> LHsQTyVars name -> HsContext name -> SDoc pp_vanilla_decl_head thing tyvars context = hsep [pprHsContext context, pprPrefixOcc (unLoc thing), ppr tyvars] pprTyClDeclFlavour :: TyClDecl a -> SDoc pprTyClDeclFlavour (ClassDecl {}) = ptext (sLit "class") pprTyClDeclFlavour (SynDecl {}) = ptext (sLit "type") pprTyClDeclFlavour (FamDecl { tcdFam = FamilyDecl { fdInfo = info }}) = pprFlavour info <+> text "family" pprTyClDeclFlavour (DataDecl { tcdDataDefn = HsDataDefn { dd_ND = nd } }) = ppr nd {- ********************************************************************* * * Data and type family declarations * * ********************************************************************* -} -- Note [FamilyResultSig] -- ~~~~~~~~~~~~~~~~~~~~~~ -- -- This data type represents the return signature of a type family. Possible -- values are: -- -- * NoSig - the user supplied no return signature: -- type family Id a where ... -- -- * KindSig - the user supplied the return kind: -- type family Id a :: * where ... -- -- * TyVarSig - user named the result with a type variable and possibly -- provided a kind signature for that variable: -- type family Id a = r where ... -- type family Id a = (r :: *) where ... -- -- Naming result of a type family is required if we want to provide -- injectivity annotation for a type family: -- type family Id a = r | r -> a where ... -- -- See also: Note [Injectivity annotation] -- Note [Injectivity annotation] -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- -- A user can declare a type family to be injective: -- -- type family Id a = r | r -> a where ... -- -- * The part after the "|" is called "injectivity annotation". -- * "r -> a" part is called "injectivity condition"; at the moment terms -- "injectivity annotation" and "injectivity condition" are synonymous -- because we only allow a single injectivity condition. -- * "r" is the "LHS of injectivity condition". LHS can only contain the -- variable naming the result of a type family. -- * "a" is the "RHS of injectivity condition". RHS contains space-separated -- type and kind variables representing the arguments of a type -- family. Variables can be omitted if a type family is not injective in -- these arguments. Example: -- type family Foo a b c = d | d -> a c where ... -- -- Note that: -- a) naming of type family result is required to provide injectivity -- annotation -- b) for associated types if the result was named then injectivity annotation -- is mandatory. Otherwise result type variable is indistinguishable from -- associated type default. -- -- It is possible that in the future this syntax will be extended to support -- more complicated injectivity annotations. For example we could declare that -- if we know the result of Plus and one of its arguments we can determine the -- other argument: -- -- type family Plus a b = (r :: Nat) | r a -> b, r b -> a where ... -- -- Here injectivity annotation would consist of two comma-separated injectivity -- conditions. -- -- See also Note [Injective type families] in TyCon type LFamilyResultSig name = Located (FamilyResultSig name) data FamilyResultSig name = -- see Note [FamilyResultSig] NoSig -- ^ - 'ApiAnnotation.AnnKeywordId' : -- For details on above see note [Api annotations] in ApiAnnotation | KindSig (LHsKind name) -- ^ - 'ApiAnnotation.AnnKeywordId' : -- 'ApiAnnotation.AnnOpenP','ApiAnnotation.AnnDcolon', -- 'ApiAnnotation.AnnCloseP' -- For details on above see note [Api annotations] in ApiAnnotation | TyVarSig (LHsTyVarBndr name) -- ^ - 'ApiAnnotation.AnnKeywordId' : -- 'ApiAnnotation.AnnOpenP','ApiAnnotation.AnnDcolon', -- 'ApiAnnotation.AnnCloseP', 'ApiAnnotation.AnnEqual' -- For details on above see note [Api annotations] in ApiAnnotation deriving ( Typeable ) deriving instance (DataId name) => Data (FamilyResultSig name) type LFamilyDecl name = Located (FamilyDecl name) data FamilyDecl name = FamilyDecl { fdInfo :: FamilyInfo name -- type/data, closed/open , fdLName :: Located name -- type constructor , fdTyVars :: LHsQTyVars name -- type variables , fdResultSig :: LFamilyResultSig name -- result signature , fdInjectivityAnn :: Maybe (LInjectivityAnn name) -- optional injectivity ann } -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnType', -- 'ApiAnnotation.AnnData', 'ApiAnnotation.AnnFamily', -- 'ApiAnnotation.AnnWhere', 'ApiAnnotation.AnnOpenP', -- 'ApiAnnotation.AnnDcolon', 'ApiAnnotation.AnnCloseP', -- 'ApiAnnotation.AnnEqual', 'ApiAnnotation.AnnRarrow', -- 'ApiAnnotation.AnnVbar' -- For details on above see note [Api annotations] in ApiAnnotation deriving ( Typeable ) deriving instance (DataId id) => Data (FamilyDecl id) type LInjectivityAnn name = Located (InjectivityAnn name) -- | If the user supplied an injectivity annotation it is represented using -- InjectivityAnn. At the moment this is a single injectivity condition - see -- Note [Injectivity annotation]. `Located name` stores the LHS of injectivity -- condition. `[Located name]` stores the RHS of injectivity condition. Example: -- -- type family Foo a b c = r | r -> a c where ... -- -- This will be represented as "InjectivityAnn `r` [`a`, `c`]" data InjectivityAnn name = InjectivityAnn (Located name) [Located name] -- ^ - 'ApiAnnotation.AnnKeywordId' : -- 'ApiAnnotation.AnnRarrow', 'ApiAnnotation.AnnVbar' -- For details on above see note [Api annotations] in ApiAnnotation deriving ( Data, Typeable ) data FamilyInfo name = DataFamily | OpenTypeFamily -- | 'Nothing' if we're in an hs-boot file and the user -- said "type family Foo x where .." | ClosedTypeFamily (Maybe [LTyFamInstEqn name]) deriving( Typeable ) deriving instance (DataId name) => Data (FamilyInfo name) -- | Does this family declaration have a complete, user-supplied kind signature? famDeclHasCusk :: FamilyDecl name -> Bool famDeclHasCusk (FamilyDecl { fdInfo = ClosedTypeFamily _ , fdTyVars = tyvars , fdResultSig = L _ resultSig }) = hsTvbAllKinded tyvars && hasReturnKindSignature resultSig famDeclHasCusk _ = True -- all open families have CUSKs! -- | Does this family declaration have user-supplied return kind signature? hasReturnKindSignature :: FamilyResultSig a -> Bool hasReturnKindSignature NoSig = False hasReturnKindSignature (TyVarSig (L _ (UserTyVar _))) = False hasReturnKindSignature _ = True -- | Maybe return name of the result type variable resultVariableName :: FamilyResultSig a -> Maybe a resultVariableName (TyVarSig sig) = Just $ hsLTyVarName sig resultVariableName _ = Nothing {- Note [Complete user-supplied kind signatures] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We kind-check declarations differently if they have a complete, user-supplied kind signature (CUSK). This is because we can safely generalise a CUSKed declaration before checking all of the others, supporting polymorphic recursion. See ghc.haskell.org/trac/ghc/wiki/GhcKinds/KindInference#Proposednewstrategy and #9200 for lots of discussion of how we got here. A declaration has a CUSK if we can know its complete kind without doing any inference, at all. Here are the rules: - A class or datatype is said to have a CUSK if and only if all of its type variables are annotated. Its result kind is, by construction, Constraint or * respectively. - A type synonym has a CUSK if and only if all of its type variables and its RHS are annotated with kinds. - A closed type family is said to have a CUSK if and only if all of its type variables and its return type are annotated. - An open type family always has a CUSK -- unannotated type variables (and return type) default to *. -} instance (OutputableBndr name) => Outputable (FamilyDecl name) where ppr = pprFamilyDecl TopLevel pprFamilyDecl :: OutputableBndr name => TopLevelFlag -> FamilyDecl name -> SDoc pprFamilyDecl top_level (FamilyDecl { fdInfo = info, fdLName = ltycon , fdTyVars = tyvars , fdResultSig = L _ result , fdInjectivityAnn = mb_inj }) = vcat [ pprFlavour info <+> pp_top_level <+> pp_vanilla_decl_head ltycon tyvars [] <+> pp_kind <+> pp_inj <+> pp_where , nest 2 $ pp_eqns ] where pp_top_level = case top_level of TopLevel -> text "family" NotTopLevel -> empty pp_kind = case result of NoSig -> empty KindSig kind -> dcolon <+> ppr kind TyVarSig tv_bndr -> text "=" <+> ppr tv_bndr pp_inj = case mb_inj of Just (L _ (InjectivityAnn lhs rhs)) -> hsep [ vbar, ppr lhs, text "->", hsep (map ppr rhs) ] Nothing -> empty (pp_where, pp_eqns) = case info of ClosedTypeFamily mb_eqns -> ( ptext (sLit "where") , case mb_eqns of Nothing -> ptext (sLit "..") Just eqns -> vcat $ map ppr_fam_inst_eqn eqns ) _ -> (empty, empty) pprFlavour :: FamilyInfo name -> SDoc pprFlavour DataFamily = ptext (sLit "data") pprFlavour OpenTypeFamily = ptext (sLit "type") pprFlavour (ClosedTypeFamily {}) = ptext (sLit "type") instance Outputable (FamilyInfo name) where ppr info = pprFlavour info <+> text "family" {- ********************************************************************* * * Data types and data constructors * * ********************************************************************* -} data HsDataDefn name -- The payload of a data type defn -- Used *both* for vanilla data declarations, -- *and* for data family instances = -- | Declares a data type or newtype, giving its constructors -- @ -- data/newtype T a = -- data/newtype instance T [a] = -- @ HsDataDefn { dd_ND :: NewOrData, dd_ctxt :: LHsContext name, -- ^ Context dd_cType :: Maybe (Located CType), dd_kindSig:: Maybe (LHsKind name), -- ^ Optional kind signature. -- -- @(Just k)@ for a GADT-style @data@, -- or @data instance@ decl, with explicit kind sig -- -- Always @Nothing@ for H98-syntax decls dd_cons :: [LConDecl name], -- ^ Data constructors -- -- For @data T a = T1 | T2 a@ -- the 'LConDecl's all have 'ConDeclH98'. -- For @data T a where { T1 :: T a }@ -- the 'LConDecls' all have 'ConDeclGADT'. dd_derivs :: HsDeriving name -- ^ Optional 'deriving' claues -- For details on above see note [Api annotations] in ApiAnnotation } deriving( Typeable ) deriving instance (DataId id) => Data (HsDataDefn id) type HsDeriving name = Maybe (Located [LHsSigType name]) -- ^ The optional 'deriving' clause of a data declaration -- -- @Nothing@ => not specified, -- @Just []@ => derive exactly what is asked -- -- It's a 'LHsSigType' because, with Generalised Newtype -- Deriving, we can mention type variables that aren't -- bound by the date type. e.g. -- data T b = ... deriving( C [a] ) -- should producd a derived instance for (C [a] (T b)) -- -- The payload of the Maybe is Located so that we have a -- place to hang the API annotations: -- - 'ApiAnnotation.AnnKeywordId' : -- 'ApiAnnotation.AnnDeriving', -- 'ApiAnnotation.AnnOpen','ApiAnnotation.AnnClose' data NewOrData = NewType -- ^ @newtype Blah ...@ | DataType -- ^ @data Blah ...@ deriving( Eq, Data, Typeable ) -- Needed because Demand derives Eq type LConDecl name = Located (ConDecl name) -- ^ May have 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnSemi' when -- in a GADT constructor list -- For details on above see note [Api annotations] in ApiAnnotation -- | -- -- @ -- data T b = forall a. Eq a => MkT a b -- MkT :: forall b a. Eq a => MkT a b -- -- data T b where -- MkT1 :: Int -> T Int -- -- data T = Int `MkT` Int -- | MkT2 -- -- data T a where -- Int `MkT` Int :: T Int -- @ -- -- - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnDotdot','ApiAnnotation.AnnCLose', -- 'ApiAnnotation.AnnEqual','ApiAnnotation.AnnVbar', -- 'ApiAnnotation.AnnDarrow','ApiAnnotation.AnnDarrow', -- 'ApiAnnotation.AnnForall','ApiAnnotation.AnnDot' -- For details on above see note [Api annotations] in ApiAnnotation data ConDecl name = ConDeclGADT { con_names :: [Located name] , con_type :: LHsSigType name -- ^ The type after the ‘::’ , con_doc :: Maybe LHsDocString -- ^ A possible Haddock comment. } | ConDeclH98 { con_name :: Located name , con_qvars :: Maybe (LHsQTyVars name) -- User-written forall (if any), and its implicit -- kind variables -- Non-Nothing needs -XExistentialQuantification -- e.g. data T a = forall b. MkT b (b->a) -- con_qvars = {b} , con_cxt :: Maybe (LHsContext name) -- ^ User-written context (if any) , con_details :: HsConDeclDetails name -- ^ Arguments , con_doc :: Maybe LHsDocString -- ^ A possible Haddock comment. } deriving (Typeable) deriving instance (DataId name) => Data (ConDecl name) type HsConDeclDetails name = HsConDetails (LBangType name) (Located [LConDeclField name]) getConNames :: ConDecl name -> [Located name] getConNames ConDeclH98 {con_name = name} = [name] getConNames ConDeclGADT {con_names = names} = names -- don't call with RdrNames, because it can't deal with HsAppsTy getConDetails :: ConDecl name -> HsConDeclDetails name getConDetails ConDeclH98 {con_details = details} = details getConDetails ConDeclGADT {con_type = ty } = details where (details,_,_,_) = gadtDeclDetails ty -- don't call with RdrNames, because it can't deal with HsAppsTy gadtDeclDetails :: LHsSigType name -> ( HsConDeclDetails name , LHsType name , LHsContext name , [LHsTyVarBndr name] ) gadtDeclDetails HsIB {hsib_body = lbody_ty} = (details,res_ty,cxt,tvs) where (tvs, cxt, tau) = splitLHsSigmaTy lbody_ty (details, res_ty) -- See Note [Sorting out the result type] = case tau of L _ (HsFunTy (L l (HsRecTy flds)) res_ty') -> (RecCon (L l flds), res_ty') _other -> (PrefixCon [], tau) hsConDeclArgTys :: HsConDeclDetails name -> [LBangType name] hsConDeclArgTys (PrefixCon tys) = tys hsConDeclArgTys (InfixCon ty1 ty2) = [ty1,ty2] hsConDeclArgTys (RecCon flds) = map (cd_fld_type . unLoc) (unLoc flds) pp_data_defn :: OutputableBndr name => (HsContext name -> SDoc) -- Printing the header -> HsDataDefn name -> SDoc pp_data_defn pp_hdr (HsDataDefn { dd_ND = new_or_data, dd_ctxt = L _ context , dd_kindSig = mb_sig , dd_cons = condecls, dd_derivs = derivings }) | null condecls = ppr new_or_data <+> pp_hdr context <+> pp_sig | otherwise = hang (ppr new_or_data <+> pp_hdr context <+> pp_sig) 2 (pp_condecls condecls $$ pp_derivings) where pp_sig = case mb_sig of Nothing -> empty Just kind -> dcolon <+> ppr kind pp_derivings = case derivings of Nothing -> empty Just (L _ ds) -> hsep [ ptext (sLit "deriving") , parens (interpp'SP ds)] instance OutputableBndr name => Outputable (HsDataDefn name) where ppr d = pp_data_defn (\_ -> ptext (sLit "Naked HsDataDefn")) d instance Outputable NewOrData where ppr NewType = ptext (sLit "newtype") ppr DataType = ptext (sLit "data") pp_condecls :: OutputableBndr name => [LConDecl name] -> SDoc pp_condecls cs@(L _ ConDeclGADT{} : _) -- In GADT syntax = hang (ptext (sLit "where")) 2 (vcat (map ppr cs)) pp_condecls cs -- In H98 syntax = equals <+> sep (punctuate (ptext (sLit " |")) (map ppr cs)) instance (OutputableBndr name) => Outputable (ConDecl name) where ppr = pprConDecl pprConDecl :: OutputableBndr name => ConDecl name -> SDoc pprConDecl (ConDeclH98 { con_name = L _ con , con_qvars = mtvs , con_cxt = mcxt , con_details = details , con_doc = doc }) = sep [ppr_mbDoc doc, pprHsForAll tvs cxt, ppr_details details] where ppr_details (InfixCon t1 t2) = hsep [ppr t1, pprInfixOcc con, ppr t2] ppr_details (PrefixCon tys) = hsep (pprPrefixOcc con : map (pprParendHsType . unLoc) tys) ppr_details (RecCon fields) = pprPrefixOcc con <+> pprConDeclFields (unLoc fields) tvs = case mtvs of Nothing -> [] Just (HsQTvs _ tvs) -> tvs cxt = fromMaybe (noLoc []) mcxt pprConDecl (ConDeclGADT { con_names = cons, con_type = res_ty, con_doc = doc }) = sep [ppr_mbDoc doc <+> ppr_con_names cons <+> dcolon <+> ppr res_ty] ppr_con_names :: (OutputableBndr name) => [Located name] -> SDoc ppr_con_names = pprWithCommas (pprPrefixOcc . unLoc) {- ************************************************************************ * * Instance declarations * * ************************************************************************ Note [Type family instance declarations in HsSyn] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The data type TyFamEqn represents one equation of a type family instance. It is parameterised over its tfe_pats field: * An ordinary type family instance declaration looks like this in source Haskell type instance T [a] Int = a -> a (or something similar for a closed family) It is represented by a TyFamInstEqn, with *type* in the tfe_pats field. * On the other hand, the *default instance* of an associated type looks like this in source Haskell class C a where type T a b type T a b = a -> b -- The default instance It is represented by a TyFamDefltEqn, with *type variables* in the tfe_pats field. -} ----------------- Type synonym family instances ------------- type LTyFamInstEqn name = Located (TyFamInstEqn name) -- ^ May have 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnSemi' -- when in a list -- For details on above see note [Api annotations] in ApiAnnotation type LTyFamDefltEqn name = Located (TyFamDefltEqn name) type HsTyPats name = HsImplicitBndrs name [LHsType name] -- ^ Type patterns (with kind and type bndrs) -- See Note [Family instance declaration binders] type TyFamInstEqn name = TyFamEqn name (HsTyPats name) type TyFamDefltEqn name = TyFamEqn name (LHsQTyVars name) -- See Note [Type family instance declarations in HsSyn] -- | One equation in a type family instance declaration -- See Note [Type family instance declarations in HsSyn] data TyFamEqn name pats = TyFamEqn { tfe_tycon :: Located name , tfe_pats :: pats , tfe_rhs :: LHsType name } -- ^ -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnEqual' -- For details on above see note [Api annotations] in ApiAnnotation deriving( Typeable ) deriving instance (DataId name, Data pats) => Data (TyFamEqn name pats) type LTyFamInstDecl name = Located (TyFamInstDecl name) data TyFamInstDecl name = TyFamInstDecl { tfid_eqn :: LTyFamInstEqn name , tfid_fvs :: PostRn name NameSet } -- ^ -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnType', -- 'ApiAnnotation.AnnInstance', -- For details on above see note [Api annotations] in ApiAnnotation deriving( Typeable ) deriving instance (DataId name) => Data (TyFamInstDecl name) ----------------- Data family instances ------------- type LDataFamInstDecl name = Located (DataFamInstDecl name) data DataFamInstDecl name = DataFamInstDecl { dfid_tycon :: Located name , dfid_pats :: HsTyPats name -- LHS , dfid_defn :: HsDataDefn name -- RHS , dfid_fvs :: PostRn name NameSet } -- Free vars for dependency analysis -- ^ -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnData', -- 'ApiAnnotation.AnnNewType','ApiAnnotation.AnnInstance', -- 'ApiAnnotation.AnnDcolon' -- 'ApiAnnotation.AnnWhere','ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnClose' -- For details on above see note [Api annotations] in ApiAnnotation deriving( Typeable ) deriving instance (DataId name) => Data (DataFamInstDecl name) ----------------- Class instances ------------- type LClsInstDecl name = Located (ClsInstDecl name) data ClsInstDecl name = ClsInstDecl { cid_poly_ty :: LHsSigType name -- Context => Class Instance-type -- Using a polytype means that the renamer conveniently -- figures out the quantified type variables for us. , cid_binds :: LHsBinds name -- Class methods , cid_sigs :: [LSig name] -- User-supplied pragmatic info , cid_tyfam_insts :: [LTyFamInstDecl name] -- Type family instances , cid_datafam_insts :: [LDataFamInstDecl name] -- Data family instances , cid_overlap_mode :: Maybe (Located OverlapMode) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnClose', -- For details on above see note [Api annotations] in ApiAnnotation } -- ^ -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnInstance', -- 'ApiAnnotation.AnnWhere', -- 'ApiAnnotation.AnnOpen','ApiAnnotation.AnnClose', -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId id) => Data (ClsInstDecl id) ----------------- Instances of all kinds ------------- type LInstDecl name = Located (InstDecl name) data InstDecl name -- Both class and family instances = ClsInstD { cid_inst :: ClsInstDecl name } | DataFamInstD -- data family instance { dfid_inst :: DataFamInstDecl name } | TyFamInstD -- type family instance { tfid_inst :: TyFamInstDecl name } deriving (Typeable) deriving instance (DataId id) => Data (InstDecl id) {- Note [Family instance declaration binders] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A {Ty|Data}FamInstDecl is a data/type family instance declaration the pats field is LHS patterns, and the tvs of the HsBSig tvs are fv(pat_tys), *including* ones that are already in scope Eg class C s t where type F t p :: * instance C w (a,b) where type F (a,b) x = x->a The tcdTyVars of the F decl are {a,b,x}, even though the F decl is nested inside the 'instance' decl. However after the renamer, the uniques will match up: instance C w7 (a8,b9) where type F (a8,b9) x10 = x10->a8 so that we can compare the type patter in the 'instance' decl and in the associated 'type' decl -} instance (OutputableBndr name) => Outputable (TyFamInstDecl name) where ppr = pprTyFamInstDecl TopLevel pprTyFamInstDecl :: OutputableBndr name => TopLevelFlag -> TyFamInstDecl name -> SDoc pprTyFamInstDecl top_lvl (TyFamInstDecl { tfid_eqn = eqn }) = ptext (sLit "type") <+> ppr_instance_keyword top_lvl <+> ppr_fam_inst_eqn eqn ppr_instance_keyword :: TopLevelFlag -> SDoc ppr_instance_keyword TopLevel = ptext (sLit "instance") ppr_instance_keyword NotTopLevel = empty ppr_fam_inst_eqn :: OutputableBndr name => LTyFamInstEqn name -> SDoc ppr_fam_inst_eqn (L _ (TyFamEqn { tfe_tycon = tycon , tfe_pats = pats , tfe_rhs = rhs })) = pp_fam_inst_lhs tycon pats [] <+> equals <+> ppr rhs ppr_fam_deflt_eqn :: OutputableBndr name => LTyFamDefltEqn name -> SDoc ppr_fam_deflt_eqn (L _ (TyFamEqn { tfe_tycon = tycon , tfe_pats = tvs , tfe_rhs = rhs })) = text "type" <+> pp_vanilla_decl_head tycon tvs [] <+> equals <+> ppr rhs instance (OutputableBndr name) => Outputable (DataFamInstDecl name) where ppr = pprDataFamInstDecl TopLevel pprDataFamInstDecl :: OutputableBndr name => TopLevelFlag -> DataFamInstDecl name -> SDoc pprDataFamInstDecl top_lvl (DataFamInstDecl { dfid_tycon = tycon , dfid_pats = pats , dfid_defn = defn }) = pp_data_defn pp_hdr defn where pp_hdr ctxt = ppr_instance_keyword top_lvl <+> pp_fam_inst_lhs tycon pats ctxt pprDataFamInstFlavour :: DataFamInstDecl name -> SDoc pprDataFamInstFlavour (DataFamInstDecl { dfid_defn = (HsDataDefn { dd_ND = nd }) }) = ppr nd pp_fam_inst_lhs :: OutputableBndr name => Located name -> HsTyPats name -> HsContext name -> SDoc pp_fam_inst_lhs thing (HsIB { hsib_body = typats }) context -- explicit type patterns = hsep [ pprHsContext context, pprPrefixOcc (unLoc thing) , hsep (map (pprParendHsType.unLoc) typats)] instance (OutputableBndr name) => Outputable (ClsInstDecl name) where ppr (ClsInstDecl { cid_poly_ty = inst_ty, cid_binds = binds , cid_sigs = sigs, cid_tyfam_insts = ats , cid_overlap_mode = mbOverlap , cid_datafam_insts = adts }) | null sigs, null ats, null adts, isEmptyBag binds -- No "where" part = top_matter | otherwise -- Laid out = vcat [ top_matter <+> ptext (sLit "where") , nest 2 $ pprDeclList $ map (pprTyFamInstDecl NotTopLevel . unLoc) ats ++ map (pprDataFamInstDecl NotTopLevel . unLoc) adts ++ pprLHsBindsForUser binds sigs ] where top_matter = ptext (sLit "instance") <+> ppOverlapPragma mbOverlap <+> ppr inst_ty ppOverlapPragma :: Maybe (Located OverlapMode) -> SDoc ppOverlapPragma mb = case mb of Nothing -> empty Just (L _ (NoOverlap _)) -> ptext (sLit "{-# NO_OVERLAP #-}") Just (L _ (Overlappable _)) -> ptext (sLit "{-# OVERLAPPABLE #-}") Just (L _ (Overlapping _)) -> ptext (sLit "{-# OVERLAPPING #-}") Just (L _ (Overlaps _)) -> ptext (sLit "{-# OVERLAPS #-}") Just (L _ (Incoherent _)) -> ptext (sLit "{-# INCOHERENT #-}") instance (OutputableBndr name) => Outputable (InstDecl name) where ppr (ClsInstD { cid_inst = decl }) = ppr decl ppr (TyFamInstD { tfid_inst = decl }) = ppr decl ppr (DataFamInstD { dfid_inst = decl }) = ppr decl -- Extract the declarations of associated data types from an instance instDeclDataFamInsts :: [LInstDecl name] -> [DataFamInstDecl name] instDeclDataFamInsts inst_decls = concatMap do_one inst_decls where do_one (L _ (ClsInstD { cid_inst = ClsInstDecl { cid_datafam_insts = fam_insts } })) = map unLoc fam_insts do_one (L _ (DataFamInstD { dfid_inst = fam_inst })) = [fam_inst] do_one (L _ (TyFamInstD {})) = [] {- ************************************************************************ * * \subsection[DerivDecl]{A stand-alone instance deriving declaration} * * ************************************************************************ -} type LDerivDecl name = Located (DerivDecl name) data DerivDecl name = DerivDecl { deriv_type :: LHsSigType name , deriv_overlap_mode :: Maybe (Located OverlapMode) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnClose', -- 'ApiAnnotation.AnnDeriving', -- 'ApiAnnotation.AnnInstance' -- For details on above see note [Api annotations] in ApiAnnotation } deriving (Typeable) deriving instance (DataId name) => Data (DerivDecl name) instance (OutputableBndr name) => Outputable (DerivDecl name) where ppr (DerivDecl ty o) = hsep [ptext (sLit "deriving instance"), ppOverlapPragma o, ppr ty] {- ************************************************************************ * * \subsection[DefaultDecl]{A @default@ declaration} * * ************************************************************************ There can only be one default declaration per module, but it is hard for the parser to check that; we pass them all through in the abstract syntax, and that restriction must be checked in the front end. -} type LDefaultDecl name = Located (DefaultDecl name) data DefaultDecl name = DefaultDecl [LHsType name] -- ^ - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnDefault', -- 'ApiAnnotation.AnnOpen','ApiAnnotation.AnnClose' -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId name) => Data (DefaultDecl name) instance (OutputableBndr name) => Outputable (DefaultDecl name) where ppr (DefaultDecl tys) = ptext (sLit "default") <+> parens (interpp'SP tys) {- ************************************************************************ * * \subsection{Foreign function interface declaration} * * ************************************************************************ -} -- foreign declarations are distinguished as to whether they define or use a -- Haskell name -- -- * the Boolean value indicates whether the pre-standard deprecated syntax -- has been used -- type LForeignDecl name = Located (ForeignDecl name) data ForeignDecl name = ForeignImport { fd_name :: Located name -- defines this name , fd_sig_ty :: LHsSigType name -- sig_ty , fd_co :: PostTc name Coercion -- rep_ty ~ sig_ty , fd_fi :: ForeignImport } | ForeignExport { fd_name :: Located name -- uses this name , fd_sig_ty :: LHsSigType name -- sig_ty , fd_co :: PostTc name Coercion -- rep_ty ~ sig_ty , fd_fe :: ForeignExport } -- ^ -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnForeign', -- 'ApiAnnotation.AnnImport','ApiAnnotation.AnnExport', -- 'ApiAnnotation.AnnDcolon' -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId name) => Data (ForeignDecl name) {- In both ForeignImport and ForeignExport: sig_ty is the type given in the Haskell code rep_ty is the representation for this type, i.e. with newtypes coerced away and type functions evaluated. Thus if the declaration is valid, then rep_ty will only use types such as Int and IO that we know how to make foreign calls with. -} noForeignImportCoercionYet :: PlaceHolder noForeignImportCoercionYet = PlaceHolder noForeignExportCoercionYet :: PlaceHolder noForeignExportCoercionYet = PlaceHolder -- Specification Of an imported external entity in dependence on the calling -- convention -- data ForeignImport = -- import of a C entity -- -- * the two strings specifying a header file or library -- may be empty, which indicates the absence of a -- header or object specification (both are not used -- in the case of `CWrapper' and when `CFunction' -- has a dynamic target) -- -- * the calling convention is irrelevant for code -- generation in the case of `CLabel', but is needed -- for pretty printing -- -- * `Safety' is irrelevant for `CLabel' and `CWrapper' -- CImport (Located CCallConv) -- ccall or stdcall (Located Safety) -- interruptible, safe or unsafe (Maybe Header) -- name of C header CImportSpec -- details of the C entity (Located SourceText) -- original source text for -- the C entity deriving (Data, Typeable) -- details of an external C entity -- data CImportSpec = CLabel CLabelString -- import address of a C label | CFunction CCallTarget -- static or dynamic function | CWrapper -- wrapper to expose closures -- (former f.e.d.) deriving (Data, Typeable) -- specification of an externally exported entity in dependence on the calling -- convention -- data ForeignExport = CExport (Located CExportSpec) -- contains the calling -- convention (Located SourceText) -- original source text for -- the C entity deriving (Data, Typeable) -- pretty printing of foreign declarations -- instance OutputableBndr name => Outputable (ForeignDecl name) where ppr (ForeignImport { fd_name = n, fd_sig_ty = ty, fd_fi = fimport }) = hang (ptext (sLit "foreign import") <+> ppr fimport <+> ppr n) 2 (dcolon <+> ppr ty) ppr (ForeignExport { fd_name = n, fd_sig_ty = ty, fd_fe = fexport }) = hang (ptext (sLit "foreign export") <+> ppr fexport <+> ppr n) 2 (dcolon <+> ppr ty) instance Outputable ForeignImport where ppr (CImport cconv safety mHeader spec _) = ppr cconv <+> ppr safety <+> char '"' <> pprCEntity spec <> char '"' where pp_hdr = case mHeader of Nothing -> empty Just (Header _ header) -> ftext header pprCEntity (CLabel lbl) = ptext (sLit "static") <+> pp_hdr <+> char '&' <> ppr lbl pprCEntity (CFunction (StaticTarget _ lbl _ isFun)) = ptext (sLit "static") <+> pp_hdr <+> (if isFun then empty else ptext (sLit "value")) <+> ppr lbl pprCEntity (CFunction (DynamicTarget)) = ptext (sLit "dynamic") pprCEntity (CWrapper) = ptext (sLit "wrapper") instance Outputable ForeignExport where ppr (CExport (L _ (CExportStatic _ lbl cconv)) _) = ppr cconv <+> char '"' <> ppr lbl <> char '"' {- ************************************************************************ * * \subsection{Transformation rules} * * ************************************************************************ -} type LRuleDecls name = Located (RuleDecls name) -- Note [Pragma source text] in BasicTypes data RuleDecls name = HsRules { rds_src :: SourceText , rds_rules :: [LRuleDecl name] } deriving (Typeable) deriving instance (DataId name) => Data (RuleDecls name) type LRuleDecl name = Located (RuleDecl name) data RuleDecl name = HsRule -- Source rule (Located (SourceText,RuleName)) -- Rule name -- Note [Pragma source text] in BasicTypes Activation [LRuleBndr name] -- Forall'd vars; after typechecking this -- includes tyvars (Located (HsExpr name)) -- LHS (PostRn name NameSet) -- Free-vars from the LHS (Located (HsExpr name)) -- RHS (PostRn name NameSet) -- Free-vars from the RHS -- ^ -- - 'ApiAnnotation.AnnKeywordId' : -- 'ApiAnnotation.AnnOpen','ApiAnnotation.AnnTilde', -- 'ApiAnnotation.AnnVal', -- 'ApiAnnotation.AnnClose', -- 'ApiAnnotation.AnnForall','ApiAnnotation.AnnDot', -- 'ApiAnnotation.AnnEqual', -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId name) => Data (RuleDecl name) flattenRuleDecls :: [LRuleDecls name] -> [LRuleDecl name] flattenRuleDecls decls = concatMap (rds_rules . unLoc) decls type LRuleBndr name = Located (RuleBndr name) data RuleBndr name = RuleBndr (Located name) | RuleBndrSig (Located name) (LHsSigWcType name) -- ^ -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnDcolon','ApiAnnotation.AnnClose' -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId name) => Data (RuleBndr name) collectRuleBndrSigTys :: [RuleBndr name] -> [LHsSigWcType name] collectRuleBndrSigTys bndrs = [ty | RuleBndrSig _ ty <- bndrs] pprFullRuleName :: Located (SourceText, RuleName) -> SDoc pprFullRuleName (L _ (_, n)) = doubleQuotes $ ftext n instance OutputableBndr name => Outputable (RuleDecls name) where ppr (HsRules _ rules) = ppr rules instance OutputableBndr name => Outputable (RuleDecl name) where ppr (HsRule name act ns lhs _fv_lhs rhs _fv_rhs) = sep [text "{-# RULES" <+> pprFullRuleName name <+> ppr act, nest 4 (pp_forall <+> pprExpr (unLoc lhs)), nest 4 (equals <+> pprExpr (unLoc rhs) <+> text "#-}") ] where pp_forall | null ns = empty | otherwise = forAllLit <+> fsep (map ppr ns) <> dot instance OutputableBndr name => Outputable (RuleBndr name) where ppr (RuleBndr name) = ppr name ppr (RuleBndrSig name ty) = ppr name <> dcolon <> ppr ty {- ************************************************************************ * * \subsection{Vectorisation declarations} * * ************************************************************************ A vectorisation pragma, one of {-# VECTORISE f = closure1 g (scalar_map g) #-} {-# VECTORISE SCALAR f #-} {-# NOVECTORISE f #-} {-# VECTORISE type T = ty #-} {-# VECTORISE SCALAR type T #-} -} type LVectDecl name = Located (VectDecl name) data VectDecl name = HsVect SourceText -- Note [Pragma source text] in BasicTypes (Located name) (LHsExpr name) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnEqual','ApiAnnotation.AnnClose' -- For details on above see note [Api annotations] in ApiAnnotation | HsNoVect SourceText -- Note [Pragma source text] in BasicTypes (Located name) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnClose' -- For details on above see note [Api annotations] in ApiAnnotation | HsVectTypeIn -- pre type-checking SourceText -- Note [Pragma source text] in BasicTypes Bool -- 'TRUE' => SCALAR declaration (Located name) (Maybe (Located name)) -- 'Nothing' => no right-hand side -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnType','ApiAnnotation.AnnClose', -- 'ApiAnnotation.AnnEqual' -- For details on above see note [Api annotations] in ApiAnnotation | HsVectTypeOut -- post type-checking Bool -- 'TRUE' => SCALAR declaration TyCon (Maybe TyCon) -- 'Nothing' => no right-hand side | HsVectClassIn -- pre type-checking SourceText -- Note [Pragma source text] in BasicTypes (Located name) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnClass','ApiAnnotation.AnnClose', -- For details on above see note [Api annotations] in ApiAnnotation | HsVectClassOut -- post type-checking Class | HsVectInstIn -- pre type-checking (always SCALAR) !!!FIXME: should be superfluous now (LHsSigType name) | HsVectInstOut -- post type-checking (always SCALAR) !!!FIXME: should be superfluous now ClsInst deriving (Typeable) deriving instance (DataId name) => Data (VectDecl name) lvectDeclName :: NamedThing name => LVectDecl name -> Name lvectDeclName (L _ (HsVect _ (L _ name) _)) = getName name lvectDeclName (L _ (HsNoVect _ (L _ name))) = getName name lvectDeclName (L _ (HsVectTypeIn _ _ (L _ name) _)) = getName name lvectDeclName (L _ (HsVectTypeOut _ tycon _)) = getName tycon lvectDeclName (L _ (HsVectClassIn _ (L _ name))) = getName name lvectDeclName (L _ (HsVectClassOut cls)) = getName cls lvectDeclName (L _ (HsVectInstIn _)) = panic "HsDecls.lvectDeclName: HsVectInstIn" lvectDeclName (L _ (HsVectInstOut _)) = panic "HsDecls.lvectDeclName: HsVectInstOut" lvectInstDecl :: LVectDecl name -> Bool lvectInstDecl (L _ (HsVectInstIn _)) = True lvectInstDecl (L _ (HsVectInstOut _)) = True lvectInstDecl _ = False instance OutputableBndr name => Outputable (VectDecl name) where ppr (HsVect _ v rhs) = sep [text "{-# VECTORISE" <+> ppr v, nest 4 $ pprExpr (unLoc rhs) <+> text "#-}" ] ppr (HsNoVect _ v) = sep [text "{-# NOVECTORISE" <+> ppr v <+> text "#-}" ] ppr (HsVectTypeIn _ False t Nothing) = sep [text "{-# VECTORISE type" <+> ppr t <+> text "#-}" ] ppr (HsVectTypeIn _ False t (Just t')) = sep [text "{-# VECTORISE type" <+> ppr t, text "=", ppr t', text "#-}" ] ppr (HsVectTypeIn _ True t Nothing) = sep [text "{-# VECTORISE SCALAR type" <+> ppr t <+> text "#-}" ] ppr (HsVectTypeIn _ True t (Just t')) = sep [text "{-# VECTORISE SCALAR type" <+> ppr t, text "=", ppr t', text "#-}" ] ppr (HsVectTypeOut False t Nothing) = sep [text "{-# VECTORISE type" <+> ppr t <+> text "#-}" ] ppr (HsVectTypeOut False t (Just t')) = sep [text "{-# VECTORISE type" <+> ppr t, text "=", ppr t', text "#-}" ] ppr (HsVectTypeOut True t Nothing) = sep [text "{-# VECTORISE SCALAR type" <+> ppr t <+> text "#-}" ] ppr (HsVectTypeOut True t (Just t')) = sep [text "{-# VECTORISE SCALAR type" <+> ppr t, text "=", ppr t', text "#-}" ] ppr (HsVectClassIn _ c) = sep [text "{-# VECTORISE class" <+> ppr c <+> text "#-}" ] ppr (HsVectClassOut c) = sep [text "{-# VECTORISE class" <+> ppr c <+> text "#-}" ] ppr (HsVectInstIn ty) = sep [text "{-# VECTORISE SCALAR instance" <+> ppr ty <+> text "#-}" ] ppr (HsVectInstOut i) = sep [text "{-# VECTORISE SCALAR instance" <+> ppr i <+> text "#-}" ] {- ************************************************************************ * * \subsection[DocDecl]{Document comments} * * ************************************************************************ -} type LDocDecl = Located (DocDecl) data DocDecl = DocCommentNext HsDocString | DocCommentPrev HsDocString | DocCommentNamed String HsDocString | DocGroup Int HsDocString deriving (Data, Typeable) -- Okay, I need to reconstruct the document comments, but for now: instance Outputable DocDecl where ppr _ = text "" docDeclDoc :: DocDecl -> HsDocString docDeclDoc (DocCommentNext d) = d docDeclDoc (DocCommentPrev d) = d docDeclDoc (DocCommentNamed _ d) = d docDeclDoc (DocGroup _ d) = d {- ************************************************************************ * * \subsection[DeprecDecl]{Deprecations} * * ************************************************************************ We use exported entities for things to deprecate. -} type LWarnDecls name = Located (WarnDecls name) -- Note [Pragma source text] in BasicTypes data WarnDecls name = Warnings { wd_src :: SourceText , wd_warnings :: [LWarnDecl name] } deriving (Data, Typeable) type LWarnDecl name = Located (WarnDecl name) data WarnDecl name = Warning [Located name] WarningTxt deriving (Data, Typeable) instance OutputableBndr name => Outputable (WarnDecls name) where ppr (Warnings _ decls) = ppr decls instance OutputableBndr name => Outputable (WarnDecl name) where ppr (Warning thing txt) = hsep [text "{-# DEPRECATED", ppr thing, doubleQuotes (ppr txt), text "#-}"] {- ************************************************************************ * * \subsection[AnnDecl]{Annotations} * * ************************************************************************ -} type LAnnDecl name = Located (AnnDecl name) data AnnDecl name = HsAnnotation SourceText -- Note [Pragma source text] in BasicTypes (AnnProvenance name) (Located (HsExpr name)) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnType' -- 'ApiAnnotation.AnnModule' -- 'ApiAnnotation.AnnClose' -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId name) => Data (AnnDecl name) instance (OutputableBndr name) => Outputable (AnnDecl name) where ppr (HsAnnotation _ provenance expr) = hsep [text "{-#", pprAnnProvenance provenance, pprExpr (unLoc expr), text "#-}"] data AnnProvenance name = ValueAnnProvenance (Located name) | TypeAnnProvenance (Located name) | ModuleAnnProvenance deriving (Data, Typeable, Functor) deriving instance Foldable AnnProvenance deriving instance Traversable AnnProvenance annProvenanceName_maybe :: AnnProvenance name -> Maybe name annProvenanceName_maybe (ValueAnnProvenance (L _ name)) = Just name annProvenanceName_maybe (TypeAnnProvenance (L _ name)) = Just name annProvenanceName_maybe ModuleAnnProvenance = Nothing pprAnnProvenance :: OutputableBndr name => AnnProvenance name -> SDoc pprAnnProvenance ModuleAnnProvenance = ptext (sLit "ANN module") pprAnnProvenance (ValueAnnProvenance (L _ name)) = ptext (sLit "ANN") <+> ppr name pprAnnProvenance (TypeAnnProvenance (L _ name)) = ptext (sLit "ANN type") <+> ppr name {- ************************************************************************ * * \subsection[RoleAnnot]{Role annotations} * * ************************************************************************ -} type LRoleAnnotDecl name = Located (RoleAnnotDecl name) -- See #8185 for more info about why role annotations are -- top-level declarations data RoleAnnotDecl name = RoleAnnotDecl (Located name) -- type constructor [Located (Maybe Role)] -- optional annotations -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnType', -- 'ApiAnnotation.AnnRole' -- For details on above see note [Api annotations] in ApiAnnotation deriving (Data, Typeable) instance OutputableBndr name => Outputable (RoleAnnotDecl name) where ppr (RoleAnnotDecl ltycon roles) = ptext (sLit "type role") <+> ppr ltycon <+> hsep (map (pp_role . unLoc) roles) where pp_role Nothing = underscore pp_role (Just r) = ppr r roleAnnotDeclName :: RoleAnnotDecl name -> name roleAnnotDeclName (RoleAnnotDecl (L _ name) _) = name