{- (c) The University of Glasgow 2006 (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 -} {-# LANGUAGE DeriveDataTypeable, DeriveFunctor, DeriveFoldable, DeriveTraversable #-} {-# LANGUAGE CPP #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE UndecidableInstances #-} -- Wrinkle in Note [Trees That Grow] -- in module GHC.Hs.Extension {-# LANGUAGE ConstraintKinds #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE TypeApplications #-} {-# LANGUAGE ScopedTypeVariables #-} {-# OPTIONS_GHC -Wno-incomplete-record-updates #-} -- | Abstract syntax of global declarations. -- -- Definitions for: @SynDecl@ and @ConDecl@, @ClassDecl@, -- @InstDecl@, @DefaultDecl@ and @ForeignDecl@. module GHC.Hs.Decls ( -- * Toplevel declarations HsDecl(..), LHsDecl, HsDataDefn(..), HsDeriving, LHsFunDep, HsDerivingClause(..), LHsDerivingClause, NewOrData(..), newOrDataToFlavour, StandaloneKindSig(..), LStandaloneKindSig, standaloneKindSigName, -- ** Class or type declarations TyClDecl(..), LTyClDecl, DataDeclRn(..), TyClGroup(..), tyClGroupTyClDecls, tyClGroupInstDecls, tyClGroupRoleDecls, tyClGroupKindSigs, isClassDecl, isDataDecl, isSynDecl, tcdName, isFamilyDecl, isTypeFamilyDecl, isDataFamilyDecl, isOpenTypeFamilyInfo, isClosedTypeFamilyInfo, tyFamInstDeclName, tyFamInstDeclLName, countTyClDecls, pprTyClDeclFlavour, tyClDeclLName, tyClDeclTyVars, hsDeclHasCusk, famResultKindSignature, FamilyDecl(..), LFamilyDecl, -- ** Instance declarations InstDecl(..), LInstDecl, FamilyInfo(..), TyFamInstDecl(..), LTyFamInstDecl, instDeclDataFamInsts, TyFamDefltDecl, LTyFamDefltDecl, DataFamInstDecl(..), LDataFamInstDecl, pprDataFamInstFlavour, pprTyFamInstDecl, pprHsFamInstLHS, FamInstEqn, LFamInstEqn, FamEqn(..), TyFamInstEqn, LTyFamInstEqn, HsTyPats, LClsInstDecl, ClsInstDecl(..), -- ** Standalone deriving declarations DerivDecl(..), LDerivDecl, -- ** Deriving strategies DerivStrategy(..), LDerivStrategy, derivStrategyName, foldDerivStrategy, mapDerivStrategy, -- ** @RULE@ declarations LRuleDecls,RuleDecls(..),RuleDecl(..),LRuleDecl,HsRuleRn(..), RuleBndr(..),LRuleBndr, collectRuleBndrSigTys, flattenRuleDecls, pprFullRuleName, -- ** @default@ declarations DefaultDecl(..), LDefaultDecl, -- ** Template haskell declaration splice SpliceExplicitFlag(..), SpliceDecl(..), LSpliceDecl, -- ** Foreign function interface declarations ForeignDecl(..), LForeignDecl, ForeignImport(..), ForeignExport(..), CImportSpec(..), -- ** Data-constructor declarations ConDecl(..), LConDecl, HsConDeclDetails, hsConDeclArgTys, hsConDeclTheta, getConNames, getConArgs, -- ** 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, familyDeclLName, familyDeclName, -- * Grouping HsGroup(..), emptyRdrGroup, emptyRnGroup, appendGroups, hsGroupInstDecls, hsGroupTopLevelFixitySigs, partitionBindsAndSigs, ) where -- friends: import GHC.Prelude import {-# SOURCE #-} GHC.Hs.Expr( HsExpr, HsSplice, pprExpr, pprSpliceDecl ) -- Because Expr imports Decls via HsBracket import GHC.Hs.Binds import GHC.Hs.Type import GHC.Hs.Doc import GHC.Core.TyCon import GHC.Types.Basic import GHC.Core.Coercion import GHC.Types.ForeignCall import GHC.Hs.Extension import GHC.Types.Name import GHC.Types.Name.Set -- others: import GHC.Core.Class import GHC.Utils.Outputable import GHC.Utils.Misc import GHC.Types.SrcLoc import GHC.Core.Type import GHC.Data.Bag import GHC.Data.Maybe import Data.Data hiding (TyCon,Fixity, Infix) {- ************************************************************************ * * \subsection[HsDecl]{Declarations} * * ************************************************************************ -} type LHsDecl p = Located (HsDecl p) -- ^ When in a list this may have -- -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnSemi' -- -- For details on above see note [Api annotations] in GHC.Parser.Annotation -- | A Haskell Declaration data HsDecl p = TyClD (XTyClD p) (TyClDecl p) -- ^ Type or Class Declaration | InstD (XInstD p) (InstDecl p) -- ^ Instance declaration | DerivD (XDerivD p) (DerivDecl p) -- ^ Deriving declaration | ValD (XValD p) (HsBind p) -- ^ Value declaration | SigD (XSigD p) (Sig p) -- ^ Signature declaration | KindSigD (XKindSigD p) (StandaloneKindSig p) -- ^ Standalone kind signature | DefD (XDefD p) (DefaultDecl p) -- ^ 'default' declaration | ForD (XForD p) (ForeignDecl p) -- ^ Foreign declaration | WarningD (XWarningD p) (WarnDecls p) -- ^ Warning declaration | AnnD (XAnnD p) (AnnDecl p) -- ^ Annotation declaration | RuleD (XRuleD p) (RuleDecls p) -- ^ Rule declaration | SpliceD (XSpliceD p) (SpliceDecl p) -- ^ Splice declaration -- (Includes quasi-quotes) | DocD (XDocD p) (DocDecl) -- ^ Documentation comment declaration | RoleAnnotD (XRoleAnnotD p) (RoleAnnotDecl p) -- ^Role annotation declaration | XHsDecl !(XXHsDecl p) type instance XTyClD (GhcPass _) = NoExtField type instance XInstD (GhcPass _) = NoExtField type instance XDerivD (GhcPass _) = NoExtField type instance XValD (GhcPass _) = NoExtField type instance XSigD (GhcPass _) = NoExtField type instance XKindSigD (GhcPass _) = NoExtField type instance XDefD (GhcPass _) = NoExtField type instance XForD (GhcPass _) = NoExtField type instance XWarningD (GhcPass _) = NoExtField type instance XAnnD (GhcPass _) = NoExtField type instance XRuleD (GhcPass _) = NoExtField type instance XSpliceD (GhcPass _) = NoExtField type instance XDocD (GhcPass _) = NoExtField type instance XRoleAnnotD (GhcPass _) = NoExtField type instance XXHsDecl (GhcPass _) = NoExtCon {- Note [Top-level fixity signatures in an HsGroup] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An `HsGroup p` stores every top-level fixity declarations in one of two places: 1. hs_fixds :: [LFixitySig p] This stores fixity signatures for top-level declarations (e.g., functions, data constructors, classes, type families, etc.) as well as fixity signatures for class methods written outside of the class, as in this example: infixl 4 `m1` class C1 a where m1 :: a -> a -> a 2. hs_tyclds :: [TyClGroup p] Each type class can be found in a TyClDecl inside a TyClGroup, and that TyClDecl stores the fixity signatures for its methods written inside of the class, as in this example: class C2 a where infixl 4 `m2` m2 :: a -> a -> a The story for fixity signatures for class methods is made slightly complicated by the fact that they can appear both inside and outside of the class itself, and both forms of fixity signatures are considered top-level. This matters in `GHC.Rename.Module.rnSrcDecls`, which must create a fixity environment out of all top-level fixity signatures before doing anything else. Therefore, `rnSrcDecls` must be aware of both (1) and (2) above. The `hsGroupTopLevelFixitySigs` function is responsible for collecting this information from an `HsGroup`. One might wonder why we even bother separating top-level fixity signatures into two places at all. That is, why not just take the fixity signatures from `hs_tyclds` and put them into `hs_fixds` so that they are all in one location? This ends up causing problems for `GHC.HsToCore.Quote.repTopDs`, which translates each fixity signature in `hs_fixds` and `hs_tyclds` into a Template Haskell `Dec`. If there are any duplicate signatures between the two fields, this will result in an error (#17608). -} -- | Partition a list of HsDecls into function/pattern bindings, signatures, -- type family declarations, type family instances, and documentation comments. -- -- Panics when given a declaration that cannot be put into any of the output -- groups. -- -- The primary use of this function is to implement -- 'GHC.Parser.PostProcess.cvBindsAndSigs'. partitionBindsAndSigs :: [LHsDecl GhcPs] -> (LHsBinds GhcPs, [LSig GhcPs], [LFamilyDecl GhcPs], [LTyFamInstDecl GhcPs], [LDataFamInstDecl GhcPs], [LDocDecl]) partitionBindsAndSigs = go where go [] = (emptyBag, [], [], [], [], []) go ((L l decl) : ds) = let (bs, ss, ts, tfis, dfis, docs) = go ds in case decl of ValD _ b -> (L l b `consBag` bs, ss, ts, tfis, dfis, docs) SigD _ s -> (bs, L l s : ss, ts, tfis, dfis, docs) TyClD _ (FamDecl _ t) -> (bs, ss, L l t : ts, tfis, dfis, docs) InstD _ (TyFamInstD { tfid_inst = tfi }) -> (bs, ss, ts, L l tfi : tfis, dfis, docs) InstD _ (DataFamInstD { dfid_inst = dfi }) -> (bs, ss, ts, tfis, L l dfi : dfis, docs) DocD _ d -> (bs, ss, ts, tfis, dfis, L l d : docs) _ -> pprPanic "partitionBindsAndSigs" (ppr decl) -- | Haskell Group -- -- A 'HsDecl' is categorised into a 'HsGroup' before being -- fed to the renamer. data HsGroup p = HsGroup { hs_ext :: XCHsGroup p, hs_valds :: HsValBinds p, hs_splcds :: [LSpliceDecl p], hs_tyclds :: [TyClGroup p], -- A list of mutually-recursive groups; -- This includes `InstDecl`s as well; -- Parser generates a singleton list; -- renamer does dependency analysis hs_derivds :: [LDerivDecl p], hs_fixds :: [LFixitySig p], -- A list of fixity signatures defined for top-level -- declarations and class methods (defined outside of the class -- itself). -- See Note [Top-level fixity signatures in an HsGroup] hs_defds :: [LDefaultDecl p], hs_fords :: [LForeignDecl p], hs_warnds :: [LWarnDecls p], hs_annds :: [LAnnDecl p], hs_ruleds :: [LRuleDecls p], hs_docs :: [LDocDecl] } | XHsGroup !(XXHsGroup p) type instance XCHsGroup (GhcPass _) = NoExtField type instance XXHsGroup (GhcPass _) = NoExtCon emptyGroup, emptyRdrGroup, emptyRnGroup :: HsGroup (GhcPass p) emptyRdrGroup = emptyGroup { hs_valds = emptyValBindsIn } emptyRnGroup = emptyGroup { hs_valds = emptyValBindsOut } hsGroupInstDecls :: HsGroup id -> [LInstDecl id] hsGroupInstDecls = (=<<) group_instds . hs_tyclds emptyGroup = HsGroup { hs_ext = noExtField, hs_tyclds = [], hs_derivds = [], hs_fixds = [], hs_defds = [], hs_annds = [], hs_fords = [], hs_warnds = [], hs_ruleds = [], hs_valds = error "emptyGroup hs_valds: Can't happen", hs_splcds = [], hs_docs = [] } -- | The fixity signatures for each top-level declaration and class method -- in an 'HsGroup'. -- See Note [Top-level fixity signatures in an HsGroup] hsGroupTopLevelFixitySigs :: HsGroup (GhcPass p) -> [LFixitySig (GhcPass p)] hsGroupTopLevelFixitySigs (HsGroup{ hs_fixds = fixds, hs_tyclds = tyclds }) = fixds ++ cls_fixds where cls_fixds = [ L loc sig | L _ ClassDecl{tcdSigs = sigs} <- tyClGroupTyClDecls tyclds , L loc (FixSig _ sig) <- sigs ] appendGroups :: HsGroup (GhcPass p) -> HsGroup (GhcPass p) -> HsGroup (GhcPass p) appendGroups HsGroup { hs_valds = val_groups1, hs_splcds = spliceds1, hs_tyclds = tyclds1, hs_derivds = derivds1, hs_fixds = fixds1, hs_defds = defds1, hs_annds = annds1, hs_fords = fords1, hs_warnds = warnds1, hs_ruleds = rulds1, hs_docs = docs1 } HsGroup { hs_valds = val_groups2, hs_splcds = spliceds2, hs_tyclds = tyclds2, hs_derivds = derivds2, hs_fixds = fixds2, hs_defds = defds2, hs_annds = annds2, hs_fords = fords2, hs_warnds = warnds2, hs_ruleds = rulds2, hs_docs = docs2 } = HsGroup { hs_ext = noExtField, hs_valds = val_groups1 `plusHsValBinds` val_groups2, hs_splcds = spliceds1 ++ spliceds2, hs_tyclds = tyclds1 ++ tyclds2, 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_docs = docs1 ++ docs2 } instance (OutputableBndrId p) => Outputable (HsDecl (GhcPass p)) 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 (KindSigD _ ksd) = ppr ksd ppr (RuleD _ rd) = ppr rd 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 (OutputableBndrId p) => Outputable (HsGroup (GhcPass p)) where ppr (HsGroup { hs_valds = val_decls, hs_tyclds = tycl_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 }) = vcat_mb empty [ppr_ds fix_decls, ppr_ds default_decls, ppr_ds deprec_decls, ppr_ds ann_decls, ppr_ds rule_decls, if isEmptyValBinds val_decls then Nothing else Just (ppr val_decls), ppr_ds (tyClGroupRoleDecls tycl_decls), ppr_ds (tyClGroupKindSigs tycl_decls), ppr_ds (tyClGroupTyClDecls tycl_decls), ppr_ds (tyClGroupInstDecls tycl_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 -- | Located Splice Declaration type LSpliceDecl pass = Located (SpliceDecl pass) -- | Splice Declaration data SpliceDecl p = SpliceDecl -- Top level splice (XSpliceDecl p) (Located (HsSplice p)) SpliceExplicitFlag | XSpliceDecl !(XXSpliceDecl p) type instance XSpliceDecl (GhcPass _) = NoExtField type instance XXSpliceDecl (GhcPass _) = NoExtCon instance OutputableBndrId p => Outputable (SpliceDecl (GhcPass p)) where ppr (SpliceDecl _ (L _ e) f) = pprSpliceDecl e f {- ************************************************************************ * * Type and class declarations * * ************************************************************************ Note [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 (GHC.Rename.Env.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 GHC.Types.Name.Occurrence.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 GHC.Hs.Binds), in the DefMethInfo field. (DefMethInfo is defined in GHC.Core.Class) 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 GHC.Parser.PostProcess.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 :: <type> op2 :: <type> 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 = :: <type> -- NB the '=' op2 :: <type> 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 GHC.Tc.TyCl.Instance.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} <pragma info> 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 -} -- | Located Declaration of a Type or Class type LTyClDecl pass = Located (TyClDecl pass) -- | A type or class declaration. data TyClDecl pass = -- | @type/data family T :: *->*@ -- -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnType', -- 'GHC.Parser.Annotation.AnnData', -- 'GHC.Parser.Annotation.AnnFamily','GHC.Parser.Annotation.AnnDcolon', -- 'GHC.Parser.Annotation.AnnWhere','GHC.Parser.Annotation.AnnOpenP', -- 'GHC.Parser.Annotation.AnnDcolon','GHC.Parser.Annotation.AnnCloseP', -- 'GHC.Parser.Annotation.AnnEqual','GHC.Parser.Annotation.AnnRarrow', -- 'GHC.Parser.Annotation.AnnVbar' -- For details on above see note [Api annotations] in GHC.Parser.Annotation FamDecl { tcdFExt :: XFamDecl pass, tcdFam :: FamilyDecl pass } | -- | @type@ declaration -- -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnType', -- 'GHC.Parser.Annotation.AnnEqual', -- For details on above see note [Api annotations] in GHC.Parser.Annotation SynDecl { tcdSExt :: XSynDecl pass -- ^ Post renameer, FVs , tcdLName :: Located (IdP pass) -- ^ Type constructor , tcdTyVars :: LHsQTyVars pass -- ^ Type variables; for an -- associated type these -- include outer binders , tcdFixity :: LexicalFixity -- ^ Fixity used in the declaration , tcdRhs :: LHsType pass } -- ^ RHS of type declaration | -- | @data@ declaration -- -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnData', -- 'GHC.Parser.Annotation.AnnFamily', -- 'GHC.Parser.Annotation.AnnNewType', -- 'GHC.Parser.Annotation.AnnNewType','GHC.Parser.Annotation.AnnDcolon' -- 'GHC.Parser.Annotation.AnnWhere', -- For details on above see note [Api annotations] in GHC.Parser.Annotation DataDecl { tcdDExt :: XDataDecl pass -- ^ Post renamer, CUSK flag, FVs , tcdLName :: Located (IdP pass) -- ^ Type constructor , tcdTyVars :: LHsQTyVars pass -- ^ Type variables -- See Note [TyVar binders for associated declarations] , tcdFixity :: LexicalFixity -- ^ Fixity used in the declaration , tcdDataDefn :: HsDataDefn pass } | ClassDecl { tcdCExt :: XClassDecl pass, -- ^ Post renamer, FVs tcdCtxt :: LHsContext pass, -- ^ Context... tcdLName :: Located (IdP pass), -- ^ Name of the class tcdTyVars :: LHsQTyVars pass, -- ^ Class type variables tcdFixity :: LexicalFixity, -- ^ Fixity used in the declaration tcdFDs :: [LHsFunDep pass], -- ^ Functional deps tcdSigs :: [LSig pass], -- ^ Methods' signatures tcdMeths :: LHsBinds pass, -- ^ Default methods tcdATs :: [LFamilyDecl pass], -- ^ Associated types; tcdATDefs :: [LTyFamDefltDecl pass], -- ^ Associated type defaults tcdDocs :: [LDocDecl] -- ^ Haddock docs } -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnClass', -- 'GHC.Parser.Annotation.AnnWhere','GHC.Parser.Annotation.AnnOpen', -- 'GHC.Parser.Annotation.AnnClose' -- - The tcdFDs will have 'GHC.Parser.Annotation.AnnVbar', -- 'GHC.Parser.Annotation.AnnComma' -- 'GHC.Parser.Annotation.AnnRarrow' -- For details on above see note [Api annotations] in GHC.Parser.Annotation | XTyClDecl !(XXTyClDecl pass) type LHsFunDep pass = Located (FunDep (Located (IdP pass))) data DataDeclRn = DataDeclRn { tcdDataCusk :: Bool -- ^ does this have a CUSK? -- See Note [CUSKs: complete user-supplied kind signatures] , tcdFVs :: NameSet } deriving Data {- Note [TyVar binders for associated decls] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For an /associated/ data, newtype, or type-family decl, the LHsQTyVars /includes/ outer binders. For example class T a where data D a c type F a b :: * type F a b = a -> a Here the data decl for 'D', and type-family decl for 'F', both include 'a' in their LHsQTyVars (tcdTyVars and fdTyVars resp). Ditto any implicit binders in the hsq_implicit field of the LHSQTyVars. The idea is that the associated type is really a top-level decl in its own right. However we are careful to use the same name 'a', so that we can match things up. c.f. Note [Associated type tyvar names] in GHC.Core.Class Note [Family instance declaration binders] -} type instance XFamDecl (GhcPass _) = NoExtField type instance XSynDecl GhcPs = NoExtField type instance XSynDecl GhcRn = NameSet -- FVs type instance XSynDecl GhcTc = NameSet -- FVs type instance XDataDecl GhcPs = NoExtField type instance XDataDecl GhcRn = DataDeclRn type instance XDataDecl GhcTc = DataDeclRn type instance XClassDecl GhcPs = LayoutInfo -- See Note [Class LayoutInfo] type instance XClassDecl GhcRn = NameSet -- FVs type instance XClassDecl GhcTc = NameSet -- FVs {- Note [Class LayoutInfo] ~~~~~~~~~~~~~~~~~~~~~~~~~~ The LayoutInfo is used to associate Haddock comments with parts of the declaration. Compare the following examples: class C a where f :: a -> Int -- ^ comment on f class C a where f :: a -> Int -- ^ comment on C Notice how "comment on f" and "comment on C" differ only by indentation level. Thus we have to record the indentation level of the class declarations. See also Note [Adding Haddock comments to the syntax tree] in GHC.Parser.PostProcess.Haddock -} type instance XXTyClDecl (GhcPass _) = NoExtCon -- Simple classifiers for TyClDecl -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- | @True@ <=> argument is a @data@\/@newtype@ -- declaration. isDataDecl :: TyClDecl pass -> Bool isDataDecl (DataDecl {}) = True isDataDecl _other = False -- | type or type instance declaration isSynDecl :: TyClDecl pass -> Bool isSynDecl (SynDecl {}) = True isSynDecl _other = False -- | type class isClassDecl :: TyClDecl pass -> Bool isClassDecl (ClassDecl {}) = True isClassDecl _ = False -- | type/data family declaration isFamilyDecl :: TyClDecl pass -> Bool isFamilyDecl (FamDecl {}) = True isFamilyDecl _other = False -- | type family declaration isTypeFamilyDecl :: TyClDecl pass -> Bool isTypeFamilyDecl (FamDecl _ (FamilyDecl { fdInfo = info })) = case info of OpenTypeFamily -> True ClosedTypeFamily {} -> True _ -> False isTypeFamilyDecl _ = False -- | open type family info isOpenTypeFamilyInfo :: FamilyInfo pass -> Bool isOpenTypeFamilyInfo OpenTypeFamily = True isOpenTypeFamilyInfo _ = False -- | closed type family info isClosedTypeFamilyInfo :: FamilyInfo pass -> Bool isClosedTypeFamilyInfo (ClosedTypeFamily {}) = True isClosedTypeFamilyInfo _ = False -- | data family declaration isDataFamilyDecl :: TyClDecl pass -> Bool isDataFamilyDecl (FamDecl _ (FamilyDecl { fdInfo = DataFamily })) = True isDataFamilyDecl _other = False -- Dealing with names tyFamInstDeclName :: TyFamInstDecl (GhcPass p) -> IdP (GhcPass p) tyFamInstDeclName = unLoc . tyFamInstDeclLName tyFamInstDeclLName :: TyFamInstDecl (GhcPass p) -> Located (IdP (GhcPass p)) tyFamInstDeclLName (TyFamInstDecl { tfid_eqn = (HsIB { hsib_body = FamEqn { feqn_tycon = ln }}) }) = ln tyClDeclLName :: TyClDecl (GhcPass p) -> Located (IdP (GhcPass p)) tyClDeclLName (FamDecl { tcdFam = fd }) = familyDeclLName fd tyClDeclLName (SynDecl { tcdLName = ln }) = ln tyClDeclLName (DataDecl { tcdLName = ln }) = ln tyClDeclLName (ClassDecl { tcdLName = ln }) = ln tcdName :: TyClDecl (GhcPass p) -> IdP (GhcPass p) tcdName = unLoc . tyClDeclLName tyClDeclTyVars :: TyClDecl pass -> LHsQTyVars pass tyClDeclTyVars (FamDecl { tcdFam = FamilyDecl { fdTyVars = tvs } }) = tvs tyClDeclTyVars d = tcdTyVars d countTyClDecls :: [TyClDecl pass] -> (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 [CUSKs: complete user-supplied kind signatures] hsDeclHasCusk :: TyClDecl GhcRn -> Bool hsDeclHasCusk (FamDecl { tcdFam = FamilyDecl { fdInfo = fam_info , fdTyVars = tyvars , fdResultSig = L _ resultSig } }) = case fam_info of ClosedTypeFamily {} -> hsTvbAllKinded tyvars && isJust (famResultKindSignature resultSig) _ -> True -- Un-associated open type/data families have CUSKs hsDeclHasCusk (SynDecl { tcdTyVars = tyvars, tcdRhs = rhs }) = hsTvbAllKinded tyvars && isJust (hsTyKindSig rhs) hsDeclHasCusk (DataDecl { tcdDExt = DataDeclRn { tcdDataCusk = cusk }}) = cusk hsDeclHasCusk (ClassDecl { tcdTyVars = tyvars }) = hsTvbAllKinded tyvars -- Pretty-printing TyClDecl -- ~~~~~~~~~~~~~~~~~~~~~~~~ instance (OutputableBndrId p) => Outputable (TyClDecl (GhcPass p)) where ppr (FamDecl { tcdFam = decl }) = ppr decl ppr (SynDecl { tcdLName = ltycon, tcdTyVars = tyvars, tcdFixity = fixity , tcdRhs = rhs }) = hang (text "type" <+> pp_vanilla_decl_head ltycon tyvars fixity noLHsContext <+> equals) 4 (ppr rhs) ppr (DataDecl { tcdLName = ltycon, tcdTyVars = tyvars, tcdFixity = fixity , tcdDataDefn = defn }) = pp_data_defn (pp_vanilla_decl_head ltycon tyvars fixity) defn ppr (ClassDecl {tcdCtxt = context, tcdLName = lclas, tcdTyVars = tyvars, tcdFixity = fixity, 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 <+> text "where" , nest 2 $ pprDeclList (map (pprFamilyDecl NotTopLevel . unLoc) ats ++ map (pprTyFamDefltDecl . unLoc) at_defs ++ pprLHsBindsForUser methods sigs) ] where top_matter = text "class" <+> pp_vanilla_decl_head lclas tyvars fixity context <+> pprFundeps (map unLoc fds) instance OutputableBndrId p => Outputable (TyClGroup (GhcPass p)) where ppr (TyClGroup { group_tyclds = tyclds , group_roles = roles , group_kisigs = kisigs , group_instds = instds } ) = hang (text "TyClGroup") 2 $ ppr kisigs $$ ppr tyclds $$ ppr roles $$ ppr instds pp_vanilla_decl_head :: (OutputableBndrId p) => Located (IdP (GhcPass p)) -> LHsQTyVars (GhcPass p) -> LexicalFixity -> LHsContext (GhcPass p) -> SDoc pp_vanilla_decl_head thing (HsQTvs { hsq_explicit = tyvars }) fixity context = hsep [pprLHsContext context, pp_tyvars tyvars] where pp_tyvars (varl:varsr) | fixity == Infix && length varsr > 1 = hsep [char '(',ppr (unLoc varl), pprInfixOcc (unLoc thing) , (ppr.unLoc) (head varsr), char ')' , hsep (map (ppr.unLoc) (tail varsr))] | fixity == Infix = hsep [ppr (unLoc varl), pprInfixOcc (unLoc thing) , hsep (map (ppr.unLoc) varsr)] | otherwise = hsep [ pprPrefixOcc (unLoc thing) , hsep (map (ppr.unLoc) (varl:varsr))] pp_tyvars [] = pprPrefixOcc (unLoc thing) pprTyClDeclFlavour :: TyClDecl (GhcPass p) -> SDoc pprTyClDeclFlavour (ClassDecl {}) = text "class" pprTyClDeclFlavour (SynDecl {}) = text "type" pprTyClDeclFlavour (FamDecl { tcdFam = FamilyDecl { fdInfo = info }}) = pprFlavour info <+> text "family" pprTyClDeclFlavour (DataDecl { tcdDataDefn = HsDataDefn { dd_ND = nd } }) = ppr nd {- Note [CUSKs: 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 https://gitlab.haskell.org/ghc/ghc/wikis/ghc-kinds/kind-inference#proposed-new-strategy and #9200 for lots of discussion of how we got here. The detection of CUSKs is enabled by the -XCUSKs extension, switched on by default. Under -XNoCUSKs, all declarations are treated as if they have no CUSK. See https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0036-kind-signatures.rst PRINCIPLE: a type declaration has a CUSK iff we could produce a separate kind signature for it, just like a type signature for a function, looking only at the header of the declaration. Examples: * data T1 (a :: *->*) (b :: *) = .... -- Has CUSK; equivalant to T1 :: (*->*) -> * -> * * data T2 a b = ... -- No CUSK; we do not want to guess T2 :: * -> * -> * -- because the full decl might be data T a b = MkT (a b) * data T3 (a :: k -> *) (b :: *) = ... -- CUSK; equivalent to T3 :: (k -> *) -> * -> * -- We lexically generalise over k to get -- T3 :: forall k. (k -> *) -> * -> * -- The generalisation is here is purely lexical, just like -- f3 :: a -> a -- means -- f3 :: forall a. a -> a * data T4 (a :: j k) = ... -- CUSK; equivalent to T4 :: j k -> * -- which we lexically generalise to T4 :: forall j k. j k -> * -- and then, if PolyKinds is on, we further generalise to -- T4 :: forall kk (j :: kk -> *) (k :: kk). j k -> * -- Again this is exactly like what happens as the term level -- when you write -- f4 :: forall a b. a b -> Int NOTE THAT * A CUSK does /not/ mean that everything about the kind signature is fully specified by the user. Look at T4 and f4: we had to do kind inference to figure out the kind-quantification. But in both cases (T4 and f4) that inference is done looking /only/ at the header of T4 (or signature for f4), not at the definition thereof. * The CUSK completely fixes the kind of the type constructor, forever. * The precise rules, for each declaration form, for whether a declaration has a CUSK are given in the user manual section "Complete user-supplied kind signatures and polymorphic recursion". But they simply implement PRINCIPLE above. * Open type families are interesting: type family T5 a b :: * There simply /is/ no accompanying declaration, so that info is all we'll ever get. So we it has a CUSK by definition, and we default any un-fixed kind variables to *. * Associated types are a bit tricker: class C6 a where type family T6 a b :: * op :: a Int -> Int Here C6 does not have a CUSK (in fact we ultimately discover that a :: * -> *). And hence neither does T6, the associated family, because we can't fix its kind until we have settled C6. Another way to say it: unlike a top-level, we /may/ discover more about a's kind from C6's definition. * A data definition with a top-level :: must explicitly bind all kind variables to the right of the ::. See test dependent/should_compile/KindLevels, which requires this case. (Naturally, any kind variable mentioned before the :: should not be bound after it.) This last point is much more debatable than the others; see #15142 comment:22 Because this is fiddly to check, there is a field in the DataDeclRn structure (included in a DataDecl after the renamer) that stores whether or not the declaration has a CUSK. -} {- ********************************************************************* * * TyClGroup Strongly connected components of type, class, instance, and role declarations * * ********************************************************************* -} {- Note [TyClGroups and dependency analysis] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A TyClGroup represents a strongly connected components of type/class/instance decls, together with the role annotations for the type/class declarations. The hs_tyclds :: [TyClGroup] field of a HsGroup is a dependency-order sequence of strongly-connected components. Invariants * The type and class declarations, group_tyclds, may depend on each other, or earlier TyClGroups, but not on later ones * The role annotations, group_roles, are role-annotations for some or all of the types and classes in group_tyclds (only). * The instance declarations, group_instds, may (and usually will) depend on group_tyclds, or on earlier TyClGroups, but not on later ones. See Note [Dependency analysis of type, class, and instance decls] in GHC.Rename.Module for more info. -} -- | Type or Class Group data TyClGroup pass -- See Note [TyClGroups and dependency analysis] = TyClGroup { group_ext :: XCTyClGroup pass , group_tyclds :: [LTyClDecl pass] , group_roles :: [LRoleAnnotDecl pass] , group_kisigs :: [LStandaloneKindSig pass] , group_instds :: [LInstDecl pass] } | XTyClGroup !(XXTyClGroup pass) type instance XCTyClGroup (GhcPass _) = NoExtField type instance XXTyClGroup (GhcPass _) = NoExtCon tyClGroupTyClDecls :: [TyClGroup pass] -> [LTyClDecl pass] tyClGroupTyClDecls = concatMap group_tyclds tyClGroupInstDecls :: [TyClGroup pass] -> [LInstDecl pass] tyClGroupInstDecls = concatMap group_instds tyClGroupRoleDecls :: [TyClGroup pass] -> [LRoleAnnotDecl pass] tyClGroupRoleDecls = concatMap group_roles tyClGroupKindSigs :: [TyClGroup pass] -> [LStandaloneKindSig pass] tyClGroupKindSigs = concatMap group_kisigs {- ********************************************************************* * * 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 GHC.Core.TyCon -} -- | Located type Family Result Signature type LFamilyResultSig pass = Located (FamilyResultSig pass) -- | type Family Result Signature data FamilyResultSig pass = -- see Note [FamilyResultSig] NoSig (XNoSig pass) -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : -- For details on above see note [Api annotations] in GHC.Parser.Annotation | KindSig (XCKindSig pass) (LHsKind pass) -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : -- 'GHC.Parser.Annotation.AnnOpenP','GHC.Parser.Annotation.AnnDcolon', -- 'GHC.Parser.Annotation.AnnCloseP' -- For details on above see note [Api annotations] in GHC.Parser.Annotation | TyVarSig (XTyVarSig pass) (LHsTyVarBndr () pass) -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : -- 'GHC.Parser.Annotation.AnnOpenP','GHC.Parser.Annotation.AnnDcolon', -- 'GHC.Parser.Annotation.AnnCloseP', 'GHC.Parser.Annotation.AnnEqual' | XFamilyResultSig !(XXFamilyResultSig pass) -- For details on above see note [Api annotations] in GHC.Parser.Annotation type instance XNoSig (GhcPass _) = NoExtField type instance XCKindSig (GhcPass _) = NoExtField type instance XTyVarSig (GhcPass _) = NoExtField type instance XXFamilyResultSig (GhcPass _) = NoExtCon -- | Located type Family Declaration type LFamilyDecl pass = Located (FamilyDecl pass) -- | type Family Declaration data FamilyDecl pass = FamilyDecl { fdExt :: XCFamilyDecl pass , fdInfo :: FamilyInfo pass -- type/data, closed/open , fdLName :: Located (IdP pass) -- type constructor , fdTyVars :: LHsQTyVars pass -- type variables -- See Note [TyVar binders for associated declarations] , fdFixity :: LexicalFixity -- Fixity used in the declaration , fdResultSig :: LFamilyResultSig pass -- result signature , fdInjectivityAnn :: Maybe (LInjectivityAnn pass) -- optional injectivity ann } | XFamilyDecl !(XXFamilyDecl pass) -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnType', -- 'GHC.Parser.Annotation.AnnData', 'GHC.Parser.Annotation.AnnFamily', -- 'GHC.Parser.Annotation.AnnWhere', 'GHC.Parser.Annotation.AnnOpenP', -- 'GHC.Parser.Annotation.AnnDcolon', 'GHC.Parser.Annotation.AnnCloseP', -- 'GHC.Parser.Annotation.AnnEqual', 'GHC.Parser.Annotation.AnnRarrow', -- 'GHC.Parser.Annotation.AnnVbar' -- For details on above see note [Api annotations] in GHC.Parser.Annotation type instance XCFamilyDecl (GhcPass _) = NoExtField type instance XXFamilyDecl (GhcPass _) = NoExtCon -- | Located Injectivity Annotation type LInjectivityAnn pass = Located (InjectivityAnn pass) -- | 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 pass = InjectivityAnn (Located (IdP pass)) [Located (IdP pass)] -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : -- 'GHC.Parser.Annotation.AnnRarrow', 'GHC.Parser.Annotation.AnnVbar' -- For details on above see note [Api annotations] in GHC.Parser.Annotation data FamilyInfo pass = DataFamily | OpenTypeFamily -- | 'Nothing' if we're in an hs-boot file and the user -- said "type family Foo x where .." | ClosedTypeFamily (Maybe [LTyFamInstEqn pass]) ------------- Functions over FamilyDecls ----------- familyDeclLName :: FamilyDecl (GhcPass p) -> Located (IdP (GhcPass p)) familyDeclLName (FamilyDecl { fdLName = n }) = n familyDeclName :: FamilyDecl (GhcPass p) -> IdP (GhcPass p) familyDeclName = unLoc . familyDeclLName famResultKindSignature :: FamilyResultSig (GhcPass p) -> Maybe (LHsKind (GhcPass p)) famResultKindSignature (NoSig _) = Nothing famResultKindSignature (KindSig _ ki) = Just ki famResultKindSignature (TyVarSig _ bndr) = case unLoc bndr of UserTyVar _ _ _ -> Nothing KindedTyVar _ _ _ ki -> Just ki -- | Maybe return name of the result type variable resultVariableName :: FamilyResultSig (GhcPass a) -> Maybe (IdP (GhcPass a)) resultVariableName (TyVarSig _ sig) = Just $ hsLTyVarName sig resultVariableName _ = Nothing ------------- Pretty printing FamilyDecls ----------- instance OutputableBndrId p => Outputable (FamilyDecl (GhcPass p)) where ppr = pprFamilyDecl TopLevel pprFamilyDecl :: (OutputableBndrId p) => TopLevelFlag -> FamilyDecl (GhcPass p) -> SDoc pprFamilyDecl top_level (FamilyDecl { fdInfo = info, fdLName = ltycon , fdTyVars = tyvars , fdFixity = fixity , fdResultSig = L _ result , fdInjectivityAnn = mb_inj }) = vcat [ pprFlavour info <+> pp_top_level <+> pp_vanilla_decl_head ltycon tyvars fixity noLHsContext <+> 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 -> ( text "where" , case mb_eqns of Nothing -> text ".." Just eqns -> vcat $ map (ppr_fam_inst_eqn . unLoc) eqns ) _ -> (empty, empty) pprFlavour :: FamilyInfo pass -> SDoc pprFlavour DataFamily = text "data" pprFlavour OpenTypeFamily = text "type" pprFlavour (ClosedTypeFamily {}) = text "type" instance Outputable (FamilyInfo pass) where ppr info = pprFlavour info <+> text "family" {- ********************************************************************* * * Data types and data constructors * * ********************************************************************* -} -- | Haskell Data type Definition data HsDataDefn pass -- 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 = <constrs> -- data/newtype instance T [a] = <constrs> -- @ HsDataDefn { dd_ext :: XCHsDataDefn pass, dd_ND :: NewOrData, dd_ctxt :: LHsContext pass, -- ^ Context dd_cType :: Maybe (Located CType), dd_kindSig:: Maybe (LHsKind pass), -- ^ 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 pass], -- ^ 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 pass -- ^ Optional 'deriving' clause -- For details on above see note [Api annotations] in GHC.Parser.Annotation } | XHsDataDefn !(XXHsDataDefn pass) type instance XCHsDataDefn (GhcPass _) = NoExtField type instance XXHsDataDefn (GhcPass _) = NoExtCon -- | Haskell Deriving clause type HsDeriving pass = Located [LHsDerivingClause pass] -- ^ The optional @deriving@ clauses of a data declaration. "Clauses" is -- plural because one can specify multiple deriving clauses using the -- @-XDerivingStrategies@ language extension. -- -- The list of 'LHsDerivingClause's corresponds to exactly what the user -- requested to derive, in order. If no deriving clauses were specified, -- the list is empty. type LHsDerivingClause pass = Located (HsDerivingClause pass) -- | A single @deriving@ clause of a data declaration. -- -- - 'GHC.Parser.Annotation.AnnKeywordId' : -- 'GHC.Parser.Annotation.AnnDeriving', 'GHC.Parser.Annotation.AnnStock', -- 'GHC.Parser.Annotation.AnnAnyClass', 'Api.AnnNewtype', -- 'GHC.Parser.Annotation.AnnOpen','GHC.Parser.Annotation.AnnClose' data HsDerivingClause pass -- See Note [Deriving strategies] in GHC.Tc.Deriv = HsDerivingClause { deriv_clause_ext :: XCHsDerivingClause pass , deriv_clause_strategy :: Maybe (LDerivStrategy pass) -- ^ The user-specified strategy (if any) to use when deriving -- 'deriv_clause_tys'. , deriv_clause_tys :: Located [LHsSigType pass] -- ^ The types to derive. -- -- It uses 'LHsSigType's because, with @-XGeneralizedNewtypeDeriving@, -- we can mention type variables that aren't bound by the datatype, e.g. -- -- > data T b = ... deriving (C [a]) -- -- should produce a derived instance for @C [a] (T b)@. } | XHsDerivingClause !(XXHsDerivingClause pass) type instance XCHsDerivingClause (GhcPass _) = NoExtField type instance XXHsDerivingClause (GhcPass _) = NoExtCon instance OutputableBndrId p => Outputable (HsDerivingClause (GhcPass p)) where ppr (HsDerivingClause { deriv_clause_strategy = dcs , deriv_clause_tys = L _ dct }) = hsep [ text "deriving" , pp_strat_before , pp_dct dct , pp_strat_after ] where -- This complexity is to distinguish between -- deriving Show -- deriving (Show) pp_dct [HsIB { hsib_body = ty }] = ppr (parenthesizeHsType appPrec ty) pp_dct _ = parens (interpp'SP dct) -- @via@ is unique in that in comes /after/ the class being derived, -- so we must special-case it. (pp_strat_before, pp_strat_after) = case dcs of Just (L _ via@ViaStrategy{}) -> (empty, ppr via) _ -> (ppDerivStrategy dcs, empty) -- | Located Standalone Kind Signature type LStandaloneKindSig pass = Located (StandaloneKindSig pass) data StandaloneKindSig pass = StandaloneKindSig (XStandaloneKindSig pass) (Located (IdP pass)) -- Why a single binder? See #16754 (LHsSigType pass) -- Why not LHsSigWcType? See Note [Wildcards in standalone kind signatures] | XStandaloneKindSig !(XXStandaloneKindSig pass) type instance XStandaloneKindSig (GhcPass p) = NoExtField type instance XXStandaloneKindSig (GhcPass p) = NoExtCon standaloneKindSigName :: StandaloneKindSig (GhcPass p) -> IdP (GhcPass p) standaloneKindSigName (StandaloneKindSig _ lname _) = unLoc lname {- Note [Wildcards in standalone kind signatures] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Standalone kind signatures enable polymorphic recursion, and it is unclear how to reconcile this with partial type signatures, so we disallow wildcards in them. We reject wildcards in 'rnStandaloneKindSignature' by returning False for 'StandaloneKindSigCtx' in 'wildCardsAllowed'. The alternative design is to have special treatment for partial standalone kind signatures, much like we have special treatment for partial type signatures in terms. However, partial standalone kind signatures are not a proper replacement for CUSKs, so this would be a separate feature. -} data NewOrData = NewType -- ^ @newtype Blah ...@ | DataType -- ^ @data Blah ...@ deriving( Eq, Data ) -- Needed because Demand derives Eq -- | Convert a 'NewOrData' to a 'TyConFlavour' newOrDataToFlavour :: NewOrData -> TyConFlavour newOrDataToFlavour NewType = NewtypeFlavour newOrDataToFlavour DataType = DataTypeFlavour -- | Located data Constructor Declaration type LConDecl pass = Located (ConDecl pass) -- ^ May have 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnSemi' when -- in a GADT constructor list -- For details on above see note [Api annotations] in GHC.Parser.Annotation -- | -- -- @ -- 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 -- @ -- -- - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnOpen', -- 'GHC.Parser.Annotation.AnnDotdot','GHC.Parser.Annotation.AnnCLose', -- 'GHC.Parser.Annotation.AnnEqual','GHC.Parser.Annotation.AnnVbar', -- 'GHC.Parser.Annotation.AnnDarrow','GHC.Parser.Annotation.AnnDarrow', -- 'GHC.Parser.Annotation.AnnForall','GHC.Parser.Annotation.AnnDot' -- For details on above see note [Api annotations] in GHC.Parser.Annotation -- | data Constructor Declaration data ConDecl pass = ConDeclGADT { con_g_ext :: XConDeclGADT pass , con_names :: [Located (IdP pass)] -- The following fields describe the type after the '::' -- See Note [GADT abstract syntax] , con_forall :: Located Bool -- ^ True <=> explicit forall -- False => hsq_explicit is empty -- -- The 'XRec' is used to anchor API -- annotations, AnnForall and AnnDot. , con_qvars :: [LHsTyVarBndr Specificity pass] -- Whether or not there is an /explicit/ forall, we still -- need to capture the implicitly-bound type/kind variables , con_mb_cxt :: Maybe (LHsContext pass) -- ^ User-written context (if any) , con_args :: HsConDeclDetails pass -- ^ Arguments; never InfixCon , con_res_ty :: LHsType pass -- ^ Result type , con_doc :: Maybe LHsDocString -- ^ A possible Haddock comment. } | ConDeclH98 { con_ext :: XConDeclH98 pass , con_name :: Located (IdP pass) , con_forall :: Located Bool -- ^ True <=> explicit user-written forall -- e.g. data T a = forall b. MkT b (b->a) -- con_ex_tvs = {b} -- False => con_ex_tvs is empty , con_ex_tvs :: [LHsTyVarBndr Specificity pass] -- ^ Existentials only , con_mb_cxt :: Maybe (LHsContext pass) -- ^ User-written context (if any) , con_args :: HsConDeclDetails pass -- ^ Arguments; can be InfixCon , con_doc :: Maybe LHsDocString -- ^ A possible Haddock comment. } | XConDecl !(XXConDecl pass) type instance XConDeclGADT GhcPs = NoExtField type instance XConDeclGADT GhcRn = [Name] -- Implicitly bound type variables type instance XConDeclGADT GhcTc = NoExtField type instance XConDeclH98 (GhcPass _) = NoExtField type instance XXConDecl (GhcPass _) = NoExtCon {- Note [GADT abstract syntax] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The types of both forms of GADT constructors are very structured, as they must consist of the quantified type variables (if provided), followed by the context (if provided), followed by the argument types (if provided), followed by the result type. (See "Wrinkle: No nested foralls or contexts" below for more discussion on the restrictions imposed here.) As a result, instead of storing the type of a GADT constructor as a single LHsType, we split it up into its constituent components for easier access. There are two broad ways to classify GADT constructors: * Record-syntax constructors. For example: data T a where K :: forall a. Ord a => { x :: [a], ... } -> T a * Prefix constructors, which do not use record syntax. For example: data T a where K :: forall a. Ord a => [a] -> ... -> T a This distinction is recorded in the `con_args :: HsConDetails pass`, which tracks if we're dealing with a RecCon or PrefixCon. It is easy to distinguish the two in the AST since record GADT constructors use HsRecTy. This distinction is made in GHC.Parser.PostProcess.mkGadtDecl. It is worth elaborating a bit more on the process of splitting the argument types of a GADT constructor, since there are some non-obvious details involved. While splitting the argument types of a record GADT constructor is easy (they are stored in an HsRecTy), splitting the arguments of a prefix GADT constructor is trickier. The basic idea is that we must split along the outermost function arrows ((->) and (#->)) in the type, which GHC.Hs.Type.splitHsFunType accomplishes. But what about type operators? Consider: C :: a :*: b -> a :*: b -> a :+: b This could parse in many different ways depending on the precedences of each type operator. In particular, if (:*:) were to have lower precedence than (->), then it could very well parse like this: a :*: ((b -> a) :*: ((b -> a) :+: b))) This would give the false impression that the whole type is part of one large return type, with no arguments. Note that we do not fully resolve the exact precedences of each user-defined type operator until the renamer, so this a more difficult task for the parser. Fortunately, there is no risk of the above happening. GHC's parser gives special treatment to function arrows, and as a result, they are always parsed with a lower precedence than any other type operator. As a result, the type above is actually parsed like this: (a :*: b) -> ((a :*: b) -> (a :+: b)) While we won't know the exact precedences of (:*:) and (:+:) until the renamer, all we are concerned about in the parser is identifying the overall shape of the argument and result types, which we can accomplish by piggybacking on the special treatment given to function arrows. In a future where function arrows aren't given special status in the parser, we will likely have to modify GHC.Parser.PostProcess.mergeOps to preserve this trick. ----- -- Wrinkle: No nested foralls or contexts ----- GADT constructors provide some freedom to change the order of foralls in their types (see Note [DataCon user type variable binders] in GHC.Core.DataCon), but this freedom is still limited. GADTs still require that all quantification occurs "prenex". That is, any explicitly quantified type variables must occur at the front of the GADT type, followed by any contexts, followed by the body of the GADT type, in precisely that order. For instance: data T where MkT1 :: forall a b. (Eq a, Eq b) => a -> b -> T -- OK MkT2 :: forall a. Eq a => forall b. a -> b -> T -- Rejected, `forall b` is nested MkT3 :: forall a b. Eq a => Eq b => a -> b -> T -- Rejected, `Eq b` is nested MkT4 :: Int -> forall a. a -> T -- Rejected, `forall a` is nested MkT5 :: forall a. Int -> Eq a => a -> T -- Rejected, `Eq a` is nested MkT6 :: (forall a. a -> T) -- Rejected, `forall a` is nested due to the surrounding parentheses MkT7 :: (Eq a => a -> t) -- Rejected, `Eq a` is nested due to the surrounding parentheses For the full details, see the "Formal syntax for GADTs" section of the GHC User's Guide. GHC enforces that GADT constructors do not have nested `forall`s or contexts in two parts: 1. GHC, in the process of splitting apart a GADT's type, extracts out the leading `forall` and context (if they are provided). To accomplish this splitting, the renamer uses the GHC.Hs.Type.splitLHsGADTPrefixTy function, which is careful not to remove parentheses surrounding the leading `forall` or context (as these parentheses can be syntactically significant). If the third result returned by splitLHsGADTPrefixTy contains any `forall`s or contexts, then they must be nested, so they will be rejected. Note that this step applies to both prefix and record GADTs alike, as they both have syntax which permits `forall`s and contexts. The difference is where this step happens: * For prefix GADTs, this happens in the renamer (in rnConDecl), as we cannot split until after the type operator fixities have been resolved. * For record GADTs, this happens in the parser (in mkGadtDecl). 2. If the GADT type is prefix, the renamer (in the ConDeclGADTPrefixPs case of rnConDecl) will then check for nested `forall`s/contexts in the body of a prefix GADT type, after it has determined what all of the argument types are. This step is necessary to catch examples like MkT4 above, where the nested quantification occurs after a visible argument type. -} -- | Haskell data Constructor Declaration Details type HsConDeclDetails pass = HsConDetails (HsScaled pass (LBangType pass)) (Located [LConDeclField pass]) getConNames :: ConDecl GhcRn -> [Located Name] getConNames ConDeclH98 {con_name = name} = [name] getConNames ConDeclGADT {con_names = names} = names getConArgs :: ConDecl GhcRn -> HsConDeclDetails GhcRn getConArgs d = con_args d hsConDeclArgTys :: HsConDeclDetails pass -> [HsScaled pass (LBangType pass)] hsConDeclArgTys (PrefixCon tys) = tys hsConDeclArgTys (InfixCon ty1 ty2) = [ty1,ty2] hsConDeclArgTys (RecCon flds) = map (hsLinear . cd_fld_type . unLoc) (unLoc flds) -- Remark: with the record syntax, constructors have all their argument -- linear, despite the fact that projections do not make sense on linear -- constructors. The design here is that the record projection themselves are -- typed to take an unrestricted argument (that is the record itself is -- unrestricted). By the transfer property, projections are then correct in -- that all the non-projected fields have multiplicity Many, and can be dropped. hsConDeclTheta :: Maybe (LHsContext pass) -> [LHsType pass] hsConDeclTheta Nothing = [] hsConDeclTheta (Just (L _ theta)) = theta pp_data_defn :: (OutputableBndrId p) => (LHsContext (GhcPass p) -> SDoc) -- Printing the header -> HsDataDefn (GhcPass p) -> SDoc pp_data_defn pp_hdr (HsDataDefn { dd_ND = new_or_data, dd_ctxt = context , dd_cType = mb_ct , dd_kindSig = mb_sig , dd_cons = condecls, dd_derivs = derivings }) | null condecls = ppr new_or_data <+> pp_ct <+> pp_hdr context <+> pp_sig <+> pp_derivings derivings | otherwise = hang (ppr new_or_data <+> pp_ct <+> pp_hdr context <+> pp_sig) 2 (pp_condecls condecls $$ pp_derivings derivings) where pp_ct = case mb_ct of Nothing -> empty Just ct -> ppr ct pp_sig = case mb_sig of Nothing -> empty Just kind -> dcolon <+> ppr kind pp_derivings (L _ ds) = vcat (map ppr ds) instance OutputableBndrId p => Outputable (HsDataDefn (GhcPass p)) where ppr d = pp_data_defn (\_ -> text "Naked HsDataDefn") d instance OutputableBndrId p => Outputable (StandaloneKindSig (GhcPass p)) where ppr (StandaloneKindSig _ v ki) = text "type" <+> pprPrefixOcc (unLoc v) <+> text "::" <+> ppr ki instance Outputable NewOrData where ppr NewType = text "newtype" ppr DataType = text "data" pp_condecls :: forall p. OutputableBndrId p => [LConDecl (GhcPass p)] -> SDoc pp_condecls cs | gadt_syntax -- In GADT syntax = hang (text "where") 2 (vcat (map ppr cs)) | otherwise -- In H98 syntax = equals <+> sep (punctuate (text " |") (map ppr cs)) where gadt_syntax = case cs of [] -> False (L _ ConDeclH98{} : _) -> False (L _ ConDeclGADT{} : _) -> True instance (OutputableBndrId p) => Outputable (ConDecl (GhcPass p)) where ppr = pprConDecl pprConDecl :: forall p. OutputableBndrId p => ConDecl (GhcPass p) -> SDoc pprConDecl (ConDeclH98 { con_name = L _ con , con_ex_tvs = ex_tvs , con_mb_cxt = mcxt , con_args = args , con_doc = doc }) = sep [ ppr_mbDoc doc , pprHsForAll (mkHsForAllInvisTele ex_tvs) cxt , ppr_details args ] where -- In ppr_details: let's not print the multiplicities (they are always 1, by -- definition) as they do not appear in an actual declaration. ppr_details (InfixCon t1 t2) = hsep [ppr (hsScaledThing t1), pprInfixOcc con, ppr (hsScaledThing t2)] ppr_details (PrefixCon tys) = hsep (pprPrefixOcc con : map (pprHsType . unLoc . hsScaledThing) tys) ppr_details (RecCon fields) = pprPrefixOcc con <+> pprConDeclFields (unLoc fields) cxt = fromMaybe noLHsContext mcxt pprConDecl (ConDeclGADT { con_names = cons, con_qvars = qvars , con_mb_cxt = mcxt, con_args = args , con_res_ty = res_ty, con_doc = doc }) = ppr_mbDoc doc <+> ppr_con_names cons <+> dcolon <+> (sep [pprHsForAll (mkHsForAllInvisTele qvars) cxt, ppr_arrow_chain (get_args args ++ [ppr res_ty]) ]) where get_args (PrefixCon args) = map ppr args get_args (RecCon fields) = [pprConDeclFields (unLoc fields)] get_args (InfixCon {}) = pprPanic "pprConDecl:GADT" (ppr cons) cxt = fromMaybe noLHsContext mcxt ppr_arrow_chain (a:as) = sep (a : map (arrow <+>) as) ppr_arrow_chain [] = empty ppr_con_names :: (OutputableBndr a) => [Located a] -> SDoc ppr_con_names = pprWithCommas (pprPrefixOcc . unLoc) {- ************************************************************************ * * Instance declarations * * ************************************************************************ Note [Type family instance declarations in HsSyn] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The data type FamEqn represents one equation of a type family instance. Aside from the pass, it is also parameterised over another field, feqn_rhs. feqn_rhs is either an HsDataDefn (for data family instances) or an LHsType (for type family instances). Type family instances also include associated type family default equations. That is because a default for a type family looks like this: class C a where type family F a b :: Type type F c d = (c,d) -- Default instance The default declaration is really just a `type instance` declaration, but one with particularly simple patterns: they must all be distinct type variables. That's because we will instantiate it (in an instance declaration for `C`) if we don't give an explicit instance for `F`. Note that the names of the variables don't need to match those of the class: it really is like a free-standing `type instance` declaration. -} ----------------- Type synonym family instances ------------- -- | Located Type Family Instance Equation type LTyFamInstEqn pass = Located (TyFamInstEqn pass) -- ^ May have 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnSemi' -- when in a list -- For details on above see note [Api annotations] in GHC.Parser.Annotation -- | Haskell Type Patterns type HsTyPats pass = [LHsTypeArg pass] {- Note [Family instance declaration binders] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The feqn_pats field of FamEqn (family instance equation) stores the LHS type (and kind) patterns. Any type (and kind) variables contained in these type patterns are bound in the hsib_vars field of the HsImplicitBndrs in FamInstEqn depending on whether or not an explicit forall is present. In the case of an explicit forall, the hsib_vars only includes kind variables not bound in the forall. Otherwise, all type (and kind) variables are bound in the hsib_vars. In the latter case, note that in particular * The hsib_vars *includes* any anonymous wildcards. For example type instance F a _ = a The hsib_vars will be {a, _}. Remember that each separate wildcard '_' gets its own unique. In this context wildcards behave just like an ordinary type variable, only anonymous. * The hsib_vars *includes* type variables 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 hsib_vars 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 pattern in the 'instance' decl and in the associated 'type' decl c.f. Note [TyVar binders for associated decls] -} -- | Type Family Instance Equation type TyFamInstEqn pass = FamInstEqn pass (LHsType pass) -- | Type family default declarations. -- A convenient synonym for 'TyFamInstDecl'. -- See @Note [Type family instance declarations in HsSyn]@. type TyFamDefltDecl = TyFamInstDecl -- | Located type family default declarations. type LTyFamDefltDecl pass = Located (TyFamDefltDecl pass) -- | Located Type Family Instance Declaration type LTyFamInstDecl pass = Located (TyFamInstDecl pass) -- | Type Family Instance Declaration newtype TyFamInstDecl pass = TyFamInstDecl { tfid_eqn :: TyFamInstEqn pass } -- ^ -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnType', -- 'GHC.Parser.Annotation.AnnInstance', -- For details on above see note [Api annotations] in GHC.Parser.Annotation ----------------- Data family instances ------------- -- | Located Data Family Instance Declaration type LDataFamInstDecl pass = Located (DataFamInstDecl pass) -- | Data Family Instance Declaration newtype DataFamInstDecl pass = DataFamInstDecl { dfid_eqn :: FamInstEqn pass (HsDataDefn pass) } -- ^ -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnData', -- 'GHC.Parser.Annotation.AnnNewType','GHC.Parser.Annotation.AnnInstance', -- 'GHC.Parser.Annotation.AnnDcolon' -- 'GHC.Parser.Annotation.AnnWhere','GHC.Parser.Annotation.AnnOpen', -- 'GHC.Parser.Annotation.AnnClose' -- For details on above see note [Api annotations] in GHC.Parser.Annotation ----------------- Family instances (common types) ------------- -- | Located Family Instance Equation type LFamInstEqn pass rhs = Located (FamInstEqn pass rhs) -- | Family Instance Equation type FamInstEqn pass rhs = HsImplicitBndrs pass (FamEqn pass rhs) -- ^ Here, the @pats@ are type patterns (with kind and type bndrs). -- See Note [Family instance declaration binders] -- | Family Equation -- -- One equation in a type family instance declaration, data family instance -- declaration, or type family default. -- See Note [Type family instance declarations in HsSyn] -- See Note [Family instance declaration binders] data FamEqn pass rhs = FamEqn { feqn_ext :: XCFamEqn pass rhs , feqn_tycon :: Located (IdP pass) , feqn_bndrs :: Maybe [LHsTyVarBndr () pass] -- ^ Optional quantified type vars , feqn_pats :: HsTyPats pass , feqn_fixity :: LexicalFixity -- ^ Fixity used in the declaration , feqn_rhs :: rhs } -- ^ -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnEqual' | XFamEqn !(XXFamEqn pass rhs) -- For details on above see note [Api annotations] in GHC.Parser.Annotation type instance XCFamEqn (GhcPass _) r = NoExtField type instance XXFamEqn (GhcPass _) r = NoExtCon ----------------- Class instances ------------- -- | Located Class Instance Declaration type LClsInstDecl pass = Located (ClsInstDecl pass) -- | Class Instance Declaration data ClsInstDecl pass = ClsInstDecl { cid_ext :: XCClsInstDecl pass , cid_poly_ty :: LHsSigType pass -- Context => Class Instance-type -- Using a polytype means that the renamer conveniently -- figures out the quantified type variables for us. , cid_binds :: LHsBinds pass -- Class methods , cid_sigs :: [LSig pass] -- User-supplied pragmatic info , cid_tyfam_insts :: [LTyFamInstDecl pass] -- Type family instances , cid_datafam_insts :: [LDataFamInstDecl pass] -- Data family instances , cid_overlap_mode :: Maybe (Located OverlapMode) -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnOpen', -- 'GHC.Parser.Annotation.AnnClose', -- For details on above see note [Api annotations] in GHC.Parser.Annotation } -- ^ -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnInstance', -- 'GHC.Parser.Annotation.AnnWhere', -- 'GHC.Parser.Annotation.AnnOpen','GHC.Parser.Annotation.AnnClose', -- For details on above see note [Api annotations] in GHC.Parser.Annotation | XClsInstDecl !(XXClsInstDecl pass) type instance XCClsInstDecl (GhcPass _) = NoExtField type instance XXClsInstDecl (GhcPass _) = NoExtCon ----------------- Instances of all kinds ------------- -- | Located Instance Declaration type LInstDecl pass = Located (InstDecl pass) -- | Instance Declaration data InstDecl pass -- Both class and family instances = ClsInstD { cid_d_ext :: XClsInstD pass , cid_inst :: ClsInstDecl pass } | DataFamInstD -- data family instance { dfid_ext :: XDataFamInstD pass , dfid_inst :: DataFamInstDecl pass } | TyFamInstD -- type family instance { tfid_ext :: XTyFamInstD pass , tfid_inst :: TyFamInstDecl pass } | XInstDecl !(XXInstDecl pass) type instance XClsInstD (GhcPass _) = NoExtField type instance XDataFamInstD (GhcPass _) = NoExtField type instance XTyFamInstD (GhcPass _) = NoExtField type instance XXInstDecl (GhcPass _) = NoExtCon instance OutputableBndrId p => Outputable (TyFamInstDecl (GhcPass p)) where ppr = pprTyFamInstDecl TopLevel pprTyFamInstDecl :: (OutputableBndrId p) => TopLevelFlag -> TyFamInstDecl (GhcPass p) -> SDoc pprTyFamInstDecl top_lvl (TyFamInstDecl { tfid_eqn = eqn }) = text "type" <+> ppr_instance_keyword top_lvl <+> ppr_fam_inst_eqn eqn ppr_instance_keyword :: TopLevelFlag -> SDoc ppr_instance_keyword TopLevel = text "instance" ppr_instance_keyword NotTopLevel = empty pprTyFamDefltDecl :: (OutputableBndrId p) => TyFamDefltDecl (GhcPass p) -> SDoc pprTyFamDefltDecl = pprTyFamInstDecl NotTopLevel ppr_fam_inst_eqn :: (OutputableBndrId p) => TyFamInstEqn (GhcPass p) -> SDoc ppr_fam_inst_eqn (HsIB { hsib_body = FamEqn { feqn_tycon = L _ tycon , feqn_bndrs = bndrs , feqn_pats = pats , feqn_fixity = fixity , feqn_rhs = rhs }}) = pprHsFamInstLHS tycon bndrs pats fixity noLHsContext <+> equals <+> ppr rhs instance OutputableBndrId p => Outputable (DataFamInstDecl (GhcPass p)) where ppr = pprDataFamInstDecl TopLevel pprDataFamInstDecl :: (OutputableBndrId p) => TopLevelFlag -> DataFamInstDecl (GhcPass p) -> SDoc pprDataFamInstDecl top_lvl (DataFamInstDecl { dfid_eqn = HsIB { hsib_body = FamEqn { feqn_tycon = L _ tycon , feqn_bndrs = bndrs , feqn_pats = pats , feqn_fixity = fixity , feqn_rhs = defn }}}) = pp_data_defn pp_hdr defn where pp_hdr ctxt = ppr_instance_keyword top_lvl <+> pprHsFamInstLHS tycon bndrs pats fixity ctxt -- pp_data_defn pretty-prints the kind sig. See #14817. pprDataFamInstFlavour :: DataFamInstDecl (GhcPass p) -> SDoc pprDataFamInstFlavour (DataFamInstDecl { dfid_eqn = HsIB { hsib_body = FamEqn { feqn_rhs = HsDataDefn { dd_ND = nd }}}}) = ppr nd pprHsFamInstLHS :: (OutputableBndrId p) => IdP (GhcPass p) -> Maybe [LHsTyVarBndr () (GhcPass p)] -> HsTyPats (GhcPass p) -> LexicalFixity -> LHsContext (GhcPass p) -> SDoc pprHsFamInstLHS thing bndrs typats fixity mb_ctxt = hsep [ pprHsExplicitForAll bndrs , pprLHsContext mb_ctxt , pp_pats typats ] where pp_pats (patl:patr:pats) | Infix <- fixity = let pp_op_app = hsep [ ppr patl, pprInfixOcc thing, ppr patr ] in case pats of [] -> pp_op_app _ -> hsep (parens pp_op_app : map ppr pats) pp_pats pats = hsep [ pprPrefixOcc thing , hsep (map ppr pats)] instance OutputableBndrId p => Outputable (ClsInstDecl (GhcPass p)) 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 <+> text "where" , nest 2 $ pprDeclList $ map (pprTyFamInstDecl NotTopLevel . unLoc) ats ++ map (pprDataFamInstDecl NotTopLevel . unLoc) adts ++ pprLHsBindsForUser binds sigs ] where top_matter = text "instance" <+> ppOverlapPragma mbOverlap <+> ppr inst_ty ppDerivStrategy :: OutputableBndrId p => Maybe (LDerivStrategy (GhcPass p)) -> SDoc ppDerivStrategy mb = case mb of Nothing -> empty Just (L _ ds) -> ppr ds ppOverlapPragma :: Maybe (Located OverlapMode) -> SDoc ppOverlapPragma mb = case mb of Nothing -> empty Just (L _ (NoOverlap s)) -> maybe_stext s "{-# NO_OVERLAP #-}" Just (L _ (Overlappable s)) -> maybe_stext s "{-# OVERLAPPABLE #-}" Just (L _ (Overlapping s)) -> maybe_stext s "{-# OVERLAPPING #-}" Just (L _ (Overlaps s)) -> maybe_stext s "{-# OVERLAPS #-}" Just (L _ (Incoherent s)) -> maybe_stext s "{-# INCOHERENT #-}" where maybe_stext NoSourceText alt = text alt maybe_stext (SourceText src) _ = text src <+> text "#-}" instance (OutputableBndrId p) => Outputable (InstDecl (GhcPass p)) 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 (GhcPass p)] -> [DataFamInstDecl (GhcPass p)] instDeclDataFamInsts inst_decls = concatMap do_one inst_decls where do_one :: LInstDecl (GhcPass p) -> [DataFamInstDecl (GhcPass p)] 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} * * ************************************************************************ -} -- | Located stand-alone 'deriving instance' declaration type LDerivDecl pass = Located (DerivDecl pass) -- | Stand-alone 'deriving instance' declaration data DerivDecl pass = DerivDecl { deriv_ext :: XCDerivDecl pass , deriv_type :: LHsSigWcType pass -- ^ The instance type to derive. -- -- It uses an 'LHsSigWcType' because the context is allowed to be a -- single wildcard: -- -- > deriving instance _ => Eq (Foo a) -- -- Which signifies that the context should be inferred. -- See Note [Inferring the instance context] in GHC.Tc.Deriv.Infer. , deriv_strategy :: Maybe (LDerivStrategy pass) , deriv_overlap_mode :: Maybe (Located OverlapMode) -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnDeriving', -- 'GHC.Parser.Annotation.AnnInstance', 'GHC.Parser.Annotation.AnnStock', -- 'GHC.Parser.Annotation.AnnAnyClass', 'Api.AnnNewtype', -- 'GHC.Parser.Annotation.AnnOpen','GHC.Parser.Annotation.AnnClose' -- For details on above see note [Api annotations] in GHC.Parser.Annotation } | XDerivDecl !(XXDerivDecl pass) type instance XCDerivDecl (GhcPass _) = NoExtField type instance XXDerivDecl (GhcPass _) = NoExtCon instance OutputableBndrId p => Outputable (DerivDecl (GhcPass p)) where ppr (DerivDecl { deriv_type = ty , deriv_strategy = ds , deriv_overlap_mode = o }) = hsep [ text "deriving" , ppDerivStrategy ds , text "instance" , ppOverlapPragma o , ppr ty ] {- ************************************************************************ * * Deriving strategies * * ************************************************************************ -} -- | A 'Located' 'DerivStrategy'. type LDerivStrategy pass = Located (DerivStrategy pass) -- | Which technique the user explicitly requested when deriving an instance. data DerivStrategy pass -- See Note [Deriving strategies] in GHC.Tc.Deriv = StockStrategy -- ^ GHC's \"standard\" strategy, which is to implement a -- custom instance for the data type. This only works -- for certain types that GHC knows about (e.g., 'Eq', -- 'Show', 'Functor' when @-XDeriveFunctor@ is enabled, -- etc.) | AnyclassStrategy -- ^ @-XDeriveAnyClass@ | NewtypeStrategy -- ^ @-XGeneralizedNewtypeDeriving@ | ViaStrategy (XViaStrategy pass) -- ^ @-XDerivingVia@ type instance XViaStrategy GhcPs = LHsSigType GhcPs type instance XViaStrategy GhcRn = LHsSigType GhcRn type instance XViaStrategy GhcTc = Type instance OutputableBndrId p => Outputable (DerivStrategy (GhcPass p)) where ppr StockStrategy = text "stock" ppr AnyclassStrategy = text "anyclass" ppr NewtypeStrategy = text "newtype" ppr (ViaStrategy ty) = text "via" <+> case ghcPass @p of GhcPs -> ppr ty GhcRn -> ppr ty GhcTc -> ppr ty -- | A short description of a @DerivStrategy'@. derivStrategyName :: DerivStrategy a -> SDoc derivStrategyName = text . go where go StockStrategy = "stock" go AnyclassStrategy = "anyclass" go NewtypeStrategy = "newtype" go (ViaStrategy {}) = "via" -- | Eliminate a 'DerivStrategy'. foldDerivStrategy :: (p ~ GhcPass pass) => r -> (XViaStrategy p -> r) -> DerivStrategy p -> r foldDerivStrategy other _ StockStrategy = other foldDerivStrategy other _ AnyclassStrategy = other foldDerivStrategy other _ NewtypeStrategy = other foldDerivStrategy _ via (ViaStrategy t) = via t -- | Map over the @via@ type if dealing with 'ViaStrategy'. Otherwise, -- return the 'DerivStrategy' unchanged. mapDerivStrategy :: (p ~ GhcPass pass) => (XViaStrategy p -> XViaStrategy p) -> DerivStrategy p -> DerivStrategy p mapDerivStrategy f ds = foldDerivStrategy ds (ViaStrategy . f) ds {- ************************************************************************ * * \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. -} -- | Located Default Declaration type LDefaultDecl pass = Located (DefaultDecl pass) -- | Default Declaration data DefaultDecl pass = DefaultDecl (XCDefaultDecl pass) [LHsType pass] -- ^ - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnDefault', -- 'GHC.Parser.Annotation.AnnOpen','GHC.Parser.Annotation.AnnClose' -- For details on above see note [Api annotations] in GHC.Parser.Annotation | XDefaultDecl !(XXDefaultDecl pass) type instance XCDefaultDecl (GhcPass _) = NoExtField type instance XXDefaultDecl (GhcPass _) = NoExtCon instance OutputableBndrId p => Outputable (DefaultDecl (GhcPass p)) where ppr (DefaultDecl _ tys) = text "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 -- | Located Foreign Declaration type LForeignDecl pass = Located (ForeignDecl pass) -- | Foreign Declaration data ForeignDecl pass = ForeignImport { fd_i_ext :: XForeignImport pass -- Post typechecker, rep_ty ~ sig_ty , fd_name :: Located (IdP pass) -- defines this name , fd_sig_ty :: LHsSigType pass -- sig_ty , fd_fi :: ForeignImport } | ForeignExport { fd_e_ext :: XForeignExport pass -- Post typechecker, rep_ty ~ sig_ty , fd_name :: Located (IdP pass) -- uses this name , fd_sig_ty :: LHsSigType pass -- sig_ty , fd_fe :: ForeignExport } -- ^ -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnForeign', -- 'GHC.Parser.Annotation.AnnImport','GHC.Parser.Annotation.AnnExport', -- 'GHC.Parser.Annotation.AnnDcolon' -- For details on above see note [Api annotations] in GHC.Parser.Annotation | XForeignDecl !(XXForeignDecl pass) {- 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. -} type instance XForeignImport GhcPs = NoExtField type instance XForeignImport GhcRn = NoExtField type instance XForeignImport GhcTc = Coercion type instance XForeignExport GhcPs = NoExtField type instance XForeignExport GhcRn = NoExtField type instance XForeignExport GhcTc = Coercion type instance XXForeignDecl (GhcPass _) = NoExtCon -- 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 -- 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 -- 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 -- pretty printing of foreign declarations -- instance OutputableBndrId p => Outputable (ForeignDecl (GhcPass p)) where ppr (ForeignImport { fd_name = n, fd_sig_ty = ty, fd_fi = fimport }) = hang (text "foreign import" <+> ppr fimport <+> ppr n) 2 (dcolon <+> ppr ty) ppr (ForeignExport { fd_name = n, fd_sig_ty = ty, fd_fe = fexport }) = hang (text "foreign export" <+> ppr fexport <+> ppr n) 2 (dcolon <+> ppr ty) instance Outputable ForeignImport where ppr (CImport cconv safety mHeader spec (L _ srcText)) = ppr cconv <+> ppr safety <+> pprWithSourceText srcText (pprCEntity spec "") where pp_hdr = case mHeader of Nothing -> empty Just (Header _ header) -> ftext header pprCEntity (CLabel lbl) _ = doubleQuotes $ text "static" <+> pp_hdr <+> char '&' <> ppr lbl pprCEntity (CFunction (StaticTarget st _lbl _ isFun)) src = if dqNeeded then doubleQuotes ce else empty where dqNeeded = (take 6 src == "static") || isJust mHeader || not isFun || st /= NoSourceText ce = -- We may need to drop leading spaces first (if take 6 src == "static" then text "static" else empty) <+> pp_hdr <+> (if isFun then empty else text "value") <+> (pprWithSourceText st empty) pprCEntity (CFunction DynamicTarget) _ = doubleQuotes $ text "dynamic" pprCEntity CWrapper _ = doubleQuotes $ text "wrapper" instance Outputable ForeignExport where ppr (CExport (L _ (CExportStatic _ lbl cconv)) _) = ppr cconv <+> char '"' <> ppr lbl <> char '"' {- ************************************************************************ * * \subsection{Rewrite rules} * * ************************************************************************ -} -- | Located Rule Declarations type LRuleDecls pass = Located (RuleDecls pass) -- Note [Pragma source text] in GHC.Types.Basic -- | Rule Declarations data RuleDecls pass = HsRules { rds_ext :: XCRuleDecls pass , rds_src :: SourceText , rds_rules :: [LRuleDecl pass] } | XRuleDecls !(XXRuleDecls pass) type instance XCRuleDecls (GhcPass _) = NoExtField type instance XXRuleDecls (GhcPass _) = NoExtCon -- | Located Rule Declaration type LRuleDecl pass = Located (RuleDecl pass) -- | Rule Declaration data RuleDecl pass = HsRule -- Source rule { rd_ext :: XHsRule pass -- ^ After renamer, free-vars from the LHS and RHS , rd_name :: Located (SourceText,RuleName) -- ^ Note [Pragma source text] in "GHC.Types.Basic" , rd_act :: Activation , rd_tyvs :: Maybe [LHsTyVarBndr () (NoGhcTc pass)] -- ^ Forall'd type vars , rd_tmvs :: [LRuleBndr pass] -- ^ Forall'd term vars, before typechecking; after typechecking -- this includes all forall'd vars , rd_lhs :: Located (HsExpr pass) , rd_rhs :: Located (HsExpr pass) } -- ^ -- - 'GHC.Parser.Annotation.AnnKeywordId' : -- 'GHC.Parser.Annotation.AnnOpen','GHC.Parser.Annotation.AnnTilde', -- 'GHC.Parser.Annotation.AnnVal', -- 'GHC.Parser.Annotation.AnnClose', -- 'GHC.Parser.Annotation.AnnForall','GHC.Parser.Annotation.AnnDot', -- 'GHC.Parser.Annotation.AnnEqual', | XRuleDecl !(XXRuleDecl pass) data HsRuleRn = HsRuleRn NameSet NameSet -- Free-vars from the LHS and RHS deriving Data type instance XHsRule GhcPs = NoExtField type instance XHsRule GhcRn = HsRuleRn type instance XHsRule GhcTc = HsRuleRn type instance XXRuleDecl (GhcPass _) = NoExtCon flattenRuleDecls :: [LRuleDecls pass] -> [LRuleDecl pass] flattenRuleDecls decls = concatMap (rds_rules . unLoc) decls -- | Located Rule Binder type LRuleBndr pass = Located (RuleBndr pass) -- | Rule Binder data RuleBndr pass = RuleBndr (XCRuleBndr pass) (Located (IdP pass)) | RuleBndrSig (XRuleBndrSig pass) (Located (IdP pass)) (HsPatSigType pass) | XRuleBndr !(XXRuleBndr pass) -- ^ -- - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnOpen', -- 'GHC.Parser.Annotation.AnnDcolon','GHC.Parser.Annotation.AnnClose' -- For details on above see note [Api annotations] in GHC.Parser.Annotation type instance XCRuleBndr (GhcPass _) = NoExtField type instance XRuleBndrSig (GhcPass _) = NoExtField type instance XXRuleBndr (GhcPass _) = NoExtCon collectRuleBndrSigTys :: [RuleBndr pass] -> [HsPatSigType pass] collectRuleBndrSigTys bndrs = [ty | RuleBndrSig _ _ ty <- bndrs] pprFullRuleName :: Located (SourceText, RuleName) -> SDoc pprFullRuleName (L _ (st, n)) = pprWithSourceText st (doubleQuotes $ ftext n) instance (OutputableBndrId p) => Outputable (RuleDecls (GhcPass p)) where ppr (HsRules { rds_src = st , rds_rules = rules }) = pprWithSourceText st (text "{-# RULES") <+> vcat (punctuate semi (map ppr rules)) <+> text "#-}" instance (OutputableBndrId p) => Outputable (RuleDecl (GhcPass p)) where ppr (HsRule { rd_name = name , rd_act = act , rd_tyvs = tys , rd_tmvs = tms , rd_lhs = lhs , rd_rhs = rhs }) = sep [pprFullRuleName name <+> ppr act, nest 4 (pp_forall_ty tys <+> pp_forall_tm tys <+> pprExpr (unLoc lhs)), nest 6 (equals <+> pprExpr (unLoc rhs)) ] where pp_forall_ty Nothing = empty pp_forall_ty (Just qtvs) = forAllLit <+> fsep (map ppr qtvs) <> dot pp_forall_tm Nothing | null tms = empty pp_forall_tm _ = forAllLit <+> fsep (map ppr tms) <> dot instance (OutputableBndrId p) => Outputable (RuleBndr (GhcPass p)) where ppr (RuleBndr _ name) = ppr name ppr (RuleBndrSig _ name ty) = parens (ppr name <> dcolon <> ppr ty) {- ************************************************************************ * * \subsection[DocDecl]{Document comments} * * ************************************************************************ -} -- | Located Documentation comment Declaration type LDocDecl = Located (DocDecl) -- | Documentation comment Declaration data DocDecl = DocCommentNext HsDocString | DocCommentPrev HsDocString | DocCommentNamed String HsDocString | DocGroup Int HsDocString deriving Data -- Okay, I need to reconstruct the document comments, but for now: instance Outputable DocDecl where ppr _ = text "<document comment>" 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. -} -- | Located Warning Declarations type LWarnDecls pass = Located (WarnDecls pass) -- Note [Pragma source text] in GHC.Types.Basic -- | Warning pragma Declarations data WarnDecls pass = Warnings { wd_ext :: XWarnings pass , wd_src :: SourceText , wd_warnings :: [LWarnDecl pass] } | XWarnDecls !(XXWarnDecls pass) type instance XWarnings (GhcPass _) = NoExtField type instance XXWarnDecls (GhcPass _) = NoExtCon -- | Located Warning pragma Declaration type LWarnDecl pass = Located (WarnDecl pass) -- | Warning pragma Declaration data WarnDecl pass = Warning (XWarning pass) [Located (IdP pass)] WarningTxt | XWarnDecl !(XXWarnDecl pass) type instance XWarning (GhcPass _) = NoExtField type instance XXWarnDecl (GhcPass _) = NoExtCon instance OutputableBndr (IdP (GhcPass p)) => Outputable (WarnDecls (GhcPass p)) where ppr (Warnings _ (SourceText src) decls) = text src <+> vcat (punctuate comma (map ppr decls)) <+> text "#-}" ppr (Warnings _ NoSourceText _decls) = panic "WarnDecls" instance OutputableBndr (IdP (GhcPass p)) => Outputable (WarnDecl (GhcPass p)) where ppr (Warning _ thing txt) = hsep ( punctuate comma (map ppr thing)) <+> ppr txt {- ************************************************************************ * * \subsection[AnnDecl]{Annotations} * * ************************************************************************ -} -- | Located Annotation Declaration type LAnnDecl pass = Located (AnnDecl pass) -- | Annotation Declaration data AnnDecl pass = HsAnnotation (XHsAnnotation pass) SourceText -- Note [Pragma source text] in GHC.Types.Basic (AnnProvenance (IdP pass)) (Located (HsExpr pass)) -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnOpen', -- 'GHC.Parser.Annotation.AnnType' -- 'GHC.Parser.Annotation.AnnModule' -- 'GHC.Parser.Annotation.AnnClose' -- For details on above see note [Api annotations] in GHC.Parser.Annotation | XAnnDecl !(XXAnnDecl pass) type instance XHsAnnotation (GhcPass _) = NoExtField type instance XXAnnDecl (GhcPass _) = NoExtCon instance (OutputableBndrId p) => Outputable (AnnDecl (GhcPass p)) where ppr (HsAnnotation _ _ provenance expr) = hsep [text "{-#", pprAnnProvenance provenance, pprExpr (unLoc expr), text "#-}"] -- | Annotation Provenance data AnnProvenance name = ValueAnnProvenance (Located name) | TypeAnnProvenance (Located name) | ModuleAnnProvenance deriving instance Functor AnnProvenance deriving instance Foldable AnnProvenance deriving instance Traversable AnnProvenance deriving instance (Data pass) => Data (AnnProvenance pass) 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 = text "ANN module" pprAnnProvenance (ValueAnnProvenance (L _ name)) = text "ANN" <+> ppr name pprAnnProvenance (TypeAnnProvenance (L _ name)) = text "ANN type" <+> ppr name {- ************************************************************************ * * \subsection[RoleAnnot]{Role annotations} * * ************************************************************************ -} -- | Located Role Annotation Declaration type LRoleAnnotDecl pass = Located (RoleAnnotDecl pass) -- See #8185 for more info about why role annotations are -- top-level declarations -- | Role Annotation Declaration data RoleAnnotDecl pass = RoleAnnotDecl (XCRoleAnnotDecl pass) (Located (IdP pass)) -- type constructor [Located (Maybe Role)] -- optional annotations -- ^ - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnType', -- 'GHC.Parser.Annotation.AnnRole' -- For details on above see note [Api annotations] in GHC.Parser.Annotation | XRoleAnnotDecl !(XXRoleAnnotDecl pass) type instance XCRoleAnnotDecl (GhcPass _) = NoExtField type instance XXRoleAnnotDecl (GhcPass _) = NoExtCon instance OutputableBndr (IdP (GhcPass p)) => Outputable (RoleAnnotDecl (GhcPass p)) where ppr (RoleAnnotDecl _ ltycon roles) = text "type role" <+> pprPrefixOcc (unLoc ltycon) <+> hsep (map (pp_role . unLoc) roles) where pp_role Nothing = underscore pp_role (Just r) = ppr r roleAnnotDeclName :: RoleAnnotDecl (GhcPass p) -> IdP (GhcPass p) roleAnnotDeclName (RoleAnnotDecl _ (L _ name) _) = name