diff options
Diffstat (limited to 'compiler/GHC/Hs/Extension.hs')
| -rw-r--r-- | compiler/GHC/Hs/Extension.hs | 639 |
1 files changed, 5 insertions, 634 deletions
diff --git a/compiler/GHC/Hs/Extension.hs b/compiler/GHC/Hs/Extension.hs index 3e9bac5442..ac79d83d0b 100644 --- a/compiler/GHC/Hs/Extension.hs +++ b/compiler/GHC/Hs/Extension.hs @@ -14,7 +14,7 @@ {-# LANGUAGE TypeFamilyDependencies #-} {-# LANGUAGE UndecidableSuperClasses #-} -- for IsPass; see Note [NoGhcTc] {-# LANGUAGE UndecidableInstances #-} -- Wrinkle in Note [Trees That Grow] - -- in module GHC.Hs.Extension + -- in module Language.Haskell.Syntax.Extension module GHC.Hs.Extension where @@ -24,6 +24,7 @@ module GHC.Hs.Extension where import GHC.Prelude import Data.Data hiding ( Fixity ) +import Language.Haskell.Syntax.Extension import GHC.Types.Name import GHC.Types.Name.Reader import GHC.Types.Var @@ -31,40 +32,7 @@ import GHC.Utils.Outputable import GHC.Types.SrcLoc (Located, unLoc, noLoc) import GHC.Utils.Panic -import Data.Kind - {- -Note [Trees that grow] -~~~~~~~~~~~~~~~~~~~~~~ - -See https://gitlab.haskell.org/ghc/ghc/wikis/implementing-trees-that-grow - -The hsSyn AST is reused across multiple compiler passes. We also have the -Template Haskell AST, and the haskell-src-exts one (outside of GHC) - -Supporting multiple passes means the AST has various warts on it to cope with -the specifics for the phases, such as the 'ValBindsOut', 'ConPatOut', -'SigPatOut' etc. - -The growable AST will allow each of these variants to be captured explicitly, -such that they only exist in the given compiler pass AST, as selected by the -type parameter to the AST. - -In addition it will allow tool writers to define their own extensions to capture -additional information for the tool, in a natural way. - -A further goal is to provide a means to harmonise the Template Haskell and -haskell-src-exts ASTs as well. - -Wrinkle: In order to print out the AST, we need to know it is Outputable. -We also sometimes need to branch on the particular pass that we're in -(e.g. to print out type information once we know it). In order to allow -both of these actions, we define OutputableBndrId, which gathers the necessary -OutputableBndr and IsPass constraints. The use of this constraint in instances -generally requires UndecidableInstances. - -See also Note [IsPass] and Note [NoGhcTc]. - Note [IsPass] ~~~~~~~~~~~~~ One challenge with the Trees That Grow approach @@ -126,91 +94,8 @@ saying that NoGhcTcPass is idempotent. -} --- | A placeholder type for TTG extension points that are not currently --- unused to represent any particular value. --- --- This should not be confused with 'NoExtCon', which are found in unused --- extension /constructors/ and therefore should never be inhabited. In --- contrast, 'NoExtField' is used in extension /points/ (e.g., as the field of --- some constructor), so it must have an inhabitant to construct AST passes --- that manipulate fields with that extension point as their type. -data NoExtField = NoExtField - deriving (Data,Eq,Ord) - -instance Outputable NoExtField where - ppr _ = text "NoExtField" - --- | Used when constructing a term with an unused extension point. -noExtField :: NoExtField -noExtField = NoExtField - --- | Used in TTG extension constructors that have yet to be extended with --- anything. If an extension constructor has 'NoExtCon' as its field, it is --- not intended to ever be constructed anywhere, and any function that consumes --- the extension constructor can eliminate it by way of 'noExtCon'. --- --- This should not be confused with 'NoExtField', which are found in unused --- extension /points/ (not /constructors/) and therefore can be inhabited. - --- See also [NoExtCon and strict fields]. -data NoExtCon - deriving (Data,Eq,Ord) - -instance Outputable NoExtCon where - ppr = noExtCon - --- | Eliminate a 'NoExtCon'. Much like 'Data.Void.absurd'. -noExtCon :: NoExtCon -> a -noExtCon x = case x of {} - --- | GHC's L prefixed variants wrap their vanilla variant in this type family, --- to add 'SrcLoc' info via 'Located'. Other passes than 'GhcPass' not --- interested in location information can define this as --- @type instance XRec NoLocated a = a@. --- See Note [XRec and SrcSpans in the AST] -type family XRec p a = r | r -> a - type instance XRec (GhcPass p) a = Located a -{- -Note [XRec and SrcSpans in the AST] -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -XRec is meant to replace most of the uses of `Located` in the AST. It is another -extension point meant to make it easier for non-GHC applications to reuse the -AST for their own purposes, and not have to deal the hassle of (perhaps) useless -SrcSpans everywhere. - -instead of `Located (HsExpr p)` or similar types, we will now have `XRec p -(HsExpr p)` - -XRec allows annotating certain points in the AST with extra information. This -maybe be source spans (for GHC), nothing (for TH), types (for HIE files), api -annotations (for exactprint) or anything else. - -This should hopefully bring us one step closer to sharing the AST between GHC -and TH. - -We use the `UnXRec`, `MapXRec` and `WrapXRec` type classes to aid us in writing -pass-polymorphic code that deals with `XRec`s --} - --- | We can strip off the XRec to access the underlying data. --- See Note [XRec and SrcSpans in the AST] -class UnXRec p where - unXRec :: XRec p a -> a - --- | We can map over the underlying type contained in an @XRec@ while preserving --- the annotation as is. --- See Note [XRec and SrcSpans in the AST] -class MapXRec p where - mapXRec :: (a -> b) -> XRec p a -> XRec p b - --- | The trivial wrapper that carries no additional information --- @noLoc@ for @GhcPass p@ --- See Note [XRec and SrcSpans in the AST] -class WrapXRec p where - wrapXRec :: a -> XRec p a - instance UnXRec (GhcPass p) where unXRec = unLoc instance MapXRec (GhcPass p) where @@ -293,8 +178,6 @@ instance IsPass 'Renamed where instance IsPass 'Typechecked where ghcPass = GhcTc --- | Maps the "normal" id type for a given pass -type family IdP p type instance IdP (GhcPass p) = IdGhcP p -- | Maps the "normal" id type for a given GHC pass @@ -303,530 +186,18 @@ type family IdGhcP pass where IdGhcP 'Renamed = Name IdGhcP 'Typechecked = Id -type LIdP p = XRec p (IdP p) - -- | Marks that a field uses the GhcRn variant even when the pass -- parameter is GhcTc. Useful for storing HsTypes in GHC.Hs.Exprs, say, because -- HsType GhcTc should never occur. -- See Note [NoGhcTc] -type family NoGhcTc (p :: Type) where - -- this way, GHC can figure out that the result is a GhcPass - NoGhcTc (GhcPass pass) = GhcPass (NoGhcTcPass pass) - NoGhcTc other = other + +-- Breaking it up this way, GHC can figure out that the result is a GhcPass +type instance NoGhcTc (GhcPass pass) = GhcPass (NoGhcTcPass pass) type family NoGhcTcPass (p :: Pass) :: Pass where NoGhcTcPass 'Typechecked = 'Renamed NoGhcTcPass other = other --- ===================================================================== --- Type families for the HsBinds extension points - --- HsLocalBindsLR type families -type family XHsValBinds x x' -type family XHsIPBinds x x' -type family XEmptyLocalBinds x x' -type family XXHsLocalBindsLR x x' - --- HsValBindsLR type families -type family XValBinds x x' -type family XXValBindsLR x x' - --- HsBindLR type families -type family XFunBind x x' -type family XPatBind x x' -type family XVarBind x x' -type family XAbsBinds x x' -type family XPatSynBind x x' -type family XXHsBindsLR x x' - --- ABExport type families -type family XABE x -type family XXABExport x - --- PatSynBind type families -type family XPSB x x' -type family XXPatSynBind x x' - --- HsIPBinds type families -type family XIPBinds x -type family XXHsIPBinds x - --- IPBind type families -type family XCIPBind x -type family XXIPBind x - --- Sig type families -type family XTypeSig x -type family XPatSynSig x -type family XClassOpSig x -type family XIdSig x -type family XFixSig x -type family XInlineSig x -type family XSpecSig x -type family XSpecInstSig x -type family XMinimalSig x -type family XSCCFunSig x -type family XCompleteMatchSig x -type family XXSig x - --- FixitySig type families -type family XFixitySig x -type family XXFixitySig x - --- StandaloneKindSig type families -type family XStandaloneKindSig x -type family XXStandaloneKindSig x - --- ===================================================================== --- Type families for the HsDecls extension points - --- HsDecl type families -type family XTyClD x -type family XInstD x -type family XDerivD x -type family XValD x -type family XSigD x -type family XKindSigD x -type family XDefD x -type family XForD x -type family XWarningD x -type family XAnnD x -type family XRuleD x -type family XSpliceD x -type family XDocD x -type family XRoleAnnotD x -type family XXHsDecl x - --- ------------------------------------- --- HsGroup type families -type family XCHsGroup x -type family XXHsGroup x - --- ------------------------------------- --- SpliceDecl type families -type family XSpliceDecl x -type family XXSpliceDecl x - --- ------------------------------------- --- TyClDecl type families -type family XFamDecl x -type family XSynDecl x -type family XDataDecl x -type family XClassDecl x -type family XXTyClDecl x - --- ------------------------------------- --- TyClGroup type families -type family XCTyClGroup x -type family XXTyClGroup x - --- ------------------------------------- --- FamilyResultSig type families -type family XNoSig x -type family XCKindSig x -- Clashes with XKindSig above -type family XTyVarSig x -type family XXFamilyResultSig x - --- ------------------------------------- --- FamilyDecl type families -type family XCFamilyDecl x -type family XXFamilyDecl x - --- ------------------------------------- --- HsDataDefn type families -type family XCHsDataDefn x -type family XXHsDataDefn x - --- ------------------------------------- --- HsDerivingClause type families -type family XCHsDerivingClause x -type family XXHsDerivingClause x - --- ------------------------------------- --- DerivClauseTys type families -type family XDctSingle x -type family XDctMulti x -type family XXDerivClauseTys x - --- ------------------------------------- --- ConDecl type families -type family XConDeclGADT x -type family XConDeclH98 x -type family XXConDecl x - --- ------------------------------------- --- FamEqn type families -type family XCFamEqn x r -type family XXFamEqn x r - --- ------------------------------------- --- ClsInstDecl type families -type family XCClsInstDecl x -type family XXClsInstDecl x - --- ------------------------------------- --- InstDecl type families -type family XClsInstD x -type family XDataFamInstD x -type family XTyFamInstD x -type family XXInstDecl x - --- ------------------------------------- --- DerivDecl type families -type family XCDerivDecl x -type family XXDerivDecl x - --- ------------------------------------- --- DerivStrategy type family -type family XViaStrategy x - --- ------------------------------------- --- DefaultDecl type families -type family XCDefaultDecl x -type family XXDefaultDecl x - --- ------------------------------------- --- ForeignDecl type families -type family XForeignImport x -type family XForeignExport x -type family XXForeignDecl x - --- ------------------------------------- --- RuleDecls type families -type family XCRuleDecls x -type family XXRuleDecls x - --- ------------------------------------- --- RuleDecl type families -type family XHsRule x -type family XXRuleDecl x - --- ------------------------------------- --- RuleBndr type families -type family XCRuleBndr x -type family XRuleBndrSig x -type family XXRuleBndr x - --- ------------------------------------- --- WarnDecls type families -type family XWarnings x -type family XXWarnDecls x - --- ------------------------------------- --- WarnDecl type families -type family XWarning x -type family XXWarnDecl x - --- ------------------------------------- --- AnnDecl type families -type family XHsAnnotation x -type family XXAnnDecl x - --- ------------------------------------- --- RoleAnnotDecl type families -type family XCRoleAnnotDecl x -type family XXRoleAnnotDecl x - --- ===================================================================== --- Type families for the HsExpr extension points - -type family XVar x -type family XUnboundVar x -type family XConLikeOut x -type family XRecFld x -type family XOverLabel x -type family XIPVar x -type family XOverLitE x -type family XLitE x -type family XLam x -type family XLamCase x -type family XApp x -type family XAppTypeE x -type family XOpApp x -type family XNegApp x -type family XPar x -type family XSectionL x -type family XSectionR x -type family XExplicitTuple x -type family XExplicitSum x -type family XCase x -type family XIf x -type family XMultiIf x -type family XLet x -type family XDo x -type family XExplicitList x -type family XRecordCon x -type family XRecordUpd x -type family XExprWithTySig x -type family XArithSeq x -type family XBracket x -type family XRnBracketOut x -type family XTcBracketOut x -type family XSpliceE x -type family XProc x -type family XStatic x -type family XTick x -type family XBinTick x -type family XPragE x -type family XXExpr x - --- ------------------------------------- --- HsPragE type families -type family XSCC x -type family XXPragE x - - --- ------------------------------------- --- AmbiguousFieldOcc type families -type family XUnambiguous x -type family XAmbiguous x -type family XXAmbiguousFieldOcc x - --- ------------------------------------- --- HsTupArg type families -type family XPresent x -type family XMissing x -type family XXTupArg x - --- ------------------------------------- --- HsSplice type families -type family XTypedSplice x -type family XUntypedSplice x -type family XQuasiQuote x -type family XSpliced x -type family XXSplice x - --- ------------------------------------- --- HsBracket type families -type family XExpBr x -type family XPatBr x -type family XDecBrL x -type family XDecBrG x -type family XTypBr x -type family XVarBr x -type family XTExpBr x -type family XXBracket x - --- ------------------------------------- --- HsCmdTop type families -type family XCmdTop x -type family XXCmdTop x - --- ------------------------------------- --- MatchGroup type families -type family XMG x b -type family XXMatchGroup x b - --- ------------------------------------- --- Match type families -type family XCMatch x b -type family XXMatch x b - --- ------------------------------------- --- GRHSs type families -type family XCGRHSs x b -type family XXGRHSs x b - --- ------------------------------------- --- GRHS type families -type family XCGRHS x b -type family XXGRHS x b - --- ------------------------------------- --- StmtLR type families -type family XLastStmt x x' b -type family XBindStmt x x' b -type family XApplicativeStmt x x' b -type family XBodyStmt x x' b -type family XLetStmt x x' b -type family XParStmt x x' b -type family XTransStmt x x' b -type family XRecStmt x x' b -type family XXStmtLR x x' b - --- ------------------------------------- --- HsCmd type families -type family XCmdArrApp x -type family XCmdArrForm x -type family XCmdApp x -type family XCmdLam x -type family XCmdPar x -type family XCmdCase x -type family XCmdLamCase x -type family XCmdIf x -type family XCmdLet x -type family XCmdDo x -type family XCmdWrap x -type family XXCmd x - --- ------------------------------------- --- ParStmtBlock type families -type family XParStmtBlock x x' -type family XXParStmtBlock x x' - --- ------------------------------------- --- ApplicativeArg type families -type family XApplicativeArgOne x -type family XApplicativeArgMany x -type family XXApplicativeArg x - --- ===================================================================== --- Type families for the HsImpExp extension points - --- TODO - --- ===================================================================== --- Type families for the HsLit extension points - --- We define a type family for each extension point. This is based on prepending --- 'X' to the constructor name, for ease of reference. -type family XHsChar x -type family XHsCharPrim x -type family XHsString x -type family XHsStringPrim x -type family XHsInt x -type family XHsIntPrim x -type family XHsWordPrim x -type family XHsInt64Prim x -type family XHsWord64Prim x -type family XHsInteger x -type family XHsRat x -type family XHsFloatPrim x -type family XHsDoublePrim x -type family XXLit x - --- ------------------------------------- --- HsOverLit type families -type family XOverLit x -type family XXOverLit x - --- ===================================================================== --- Type families for the HsPat extension points - -type family XWildPat x -type family XVarPat x -type family XLazyPat x -type family XAsPat x -type family XParPat x -type family XBangPat x -type family XListPat x -type family XTuplePat x -type family XSumPat x -type family XConPat x -type family XViewPat x -type family XSplicePat x -type family XLitPat x -type family XNPat x -type family XNPlusKPat x -type family XSigPat x -type family XCoPat x -type family XXPat x - --- ===================================================================== --- Type families for the HsTypes type families - - --- ------------------------------------- --- LHsQTyVars type families -type family XHsQTvs x -type family XXLHsQTyVars x - --- ------------------------------------- --- HsOuterTyVarBndrs type families -type family XHsOuterImplicit x -type family XHsOuterExplicit x flag -type family XXHsOuterTyVarBndrs x - --- ------------------------------------- --- HsSigType type families -type family XHsSig x -type family XXHsSigType x - --- ------------------------------------- --- HsWildCardBndrs type families -type family XHsWC x b -type family XXHsWildCardBndrs x b - --- ------------------------------------- --- HsPatSigType type families -type family XHsPS x -type family XXHsPatSigType x - --- ------------------------------------- --- HsType type families -type family XForAllTy x -type family XQualTy x -type family XTyVar x -type family XAppTy x -type family XAppKindTy x -type family XFunTy x -type family XListTy x -type family XTupleTy x -type family XSumTy x -type family XOpTy x -type family XParTy x -type family XIParamTy x -type family XStarTy x -type family XKindSig x -type family XSpliceTy x -type family XDocTy x -type family XBangTy x -type family XRecTy x -type family XExplicitListTy x -type family XExplicitTupleTy x -type family XTyLit x -type family XWildCardTy x -type family XXType x - --- --------------------------------------------------------------------- --- HsForAllTelescope type families -type family XHsForAllVis x -type family XHsForAllInvis x -type family XXHsForAllTelescope x - --- --------------------------------------------------------------------- --- HsTyVarBndr type families -type family XUserTyVar x -type family XKindedTyVar x -type family XXTyVarBndr x - --- --------------------------------------------------------------------- --- ConDeclField type families -type family XConDeclField x -type family XXConDeclField x - --- --------------------------------------------------------------------- --- FieldOcc type families -type family XCFieldOcc x -type family XXFieldOcc x - --- ===================================================================== --- Type families for the HsImpExp type families - --- ------------------------------------- --- ImportDecl type families -type family XCImportDecl x -type family XXImportDecl x - --- ------------------------------------- --- IE type families -type family XIEVar x -type family XIEThingAbs x -type family XIEThingAll x -type family XIEThingWith x -type family XIEModuleContents x -type family XIEGroup x -type family XIEDoc x -type family XIEDocNamed x -type family XXIE x - --- ------------------------------------- - - --- ===================================================================== --- End of Type family definitions --- ===================================================================== - -- |Constraint type to bundle up the requirement for 'OutputableBndr' on both -- the @id@ and the 'NoGhcTc' of it. See Note [NoGhcTc]. type OutputableBndrId pass = |