{- (c) The University of Glasgow, 1992-2006 Here we collect a variety of helper functions that construct or analyse HsSyn. All these functions deal with generic HsSyn; functions which deal with the instantiated versions are located elsewhere: Parameterised by Module ---------------- ------------- GhcPs/RdrName parser/RdrHsSyn GhcRn/Name rename/RnHsSyn GhcTc/Id typecheck/TcHsSyn -} {-# LANGUAGE CPP #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE ViewPatterns #-} module HsUtils( -- Terms mkHsPar, mkHsApp, mkHsAppType, mkHsAppTypes, mkHsCaseAlt, mkSimpleMatch, unguardedGRHSs, unguardedRHS, mkMatchGroup, mkMatch, mkPrefixFunRhs, mkHsLam, mkHsIf, mkHsWrap, mkLHsWrap, mkHsWrapCo, mkHsWrapCoR, mkLHsWrapCo, mkHsDictLet, mkHsLams, mkHsOpApp, mkHsDo, mkHsComp, mkHsWrapPat, mkHsWrapPatCo, mkLHsPar, mkHsCmdWrap, mkLHsCmdWrap, nlHsTyApp, nlHsTyApps, nlHsVar, nlHsDataCon, nlHsLit, nlHsApp, nlHsApps, nlHsSyntaxApps, nlHsIntLit, nlHsVarApps, nlHsDo, nlHsOpApp, nlHsLam, nlHsPar, nlHsIf, nlHsCase, nlList, mkLHsTupleExpr, mkLHsVarTuple, missingTupArg, typeToLHsType, -- * Constructing general big tuples -- $big_tuples mkChunkified, chunkify, -- Bindings mkFunBind, mkVarBind, mkHsVarBind, mk_easy_FunBind, mkTopFunBind, mkPatSynBind, isInfixFunBind, -- Literals mkHsIntegral, mkHsFractional, mkHsIsString, mkHsString, mkHsStringPrimLit, -- Patterns mkNPat, mkNPlusKPat, nlVarPat, nlLitPat, nlConVarPat, nlConVarPatName, nlConPat, nlConPatName, nlInfixConPat, nlNullaryConPat, nlWildConPat, nlWildPat, nlWildPatName, nlTuplePat, mkParPat, nlParPat, mkBigLHsVarTup, mkBigLHsTup, mkBigLHsVarPatTup, mkBigLHsPatTup, -- Types mkHsAppTy, mkHsAppKindTy, userHsTyVarBndrs, userHsLTyVarBndrs, mkLHsSigType, mkLHsSigWcType, mkClassOpSigs, mkHsSigEnv, nlHsAppTy, nlHsTyVar, nlHsFunTy, nlHsParTy, nlHsTyConApp, -- Stmts mkTransformStmt, mkTransformByStmt, mkBodyStmt, mkBindStmt, mkTcBindStmt, mkLastStmt, emptyTransStmt, mkGroupUsingStmt, mkGroupByUsingStmt, emptyRecStmt, emptyRecStmtName, emptyRecStmtId, mkRecStmt, unitRecStmtTc, -- Template Haskell mkHsSpliceTy, mkHsSpliceE, mkHsSpliceTE, mkUntypedSplice, mkHsQuasiQuote, unqualQuasiQuote, -- Collecting binders isUnliftedHsBind, isBangedHsBind, collectLocalBinders, collectHsValBinders, collectHsBindListBinders, collectHsIdBinders, collectHsBindsBinders, collectHsBindBinders, collectMethodBinders, collectPatBinders, collectPatsBinders, collectLStmtsBinders, collectStmtsBinders, collectLStmtBinders, collectStmtBinders, hsLTyClDeclBinders, hsTyClForeignBinders, hsPatSynSelectors, getPatSynBinds, hsForeignDeclsBinders, hsGroupBinders, hsDataFamInstBinders, -- Collecting implicit binders lStmtsImplicits, hsValBindsImplicits, lPatImplicits ) where #include "HsVersions.h" import GhcPrelude import HsDecls import HsBinds import HsExpr import HsPat import HsTypes import HsLit import PlaceHolder import HsExtension import TcEvidence import RdrName import Var import TyCoRep import Type ( filterOutInvisibleTypes ) import TysWiredIn ( unitTy ) import TcType import DataCon import ConLike import Id import Name import NameSet import NameEnv import BasicTypes import SrcLoc import FastString import Util import Bag import Outputable import Constants import TyCon import Data.Either import Data.Function import Data.List {- ************************************************************************ * * Some useful helpers for constructing syntax * * ************************************************************************ These functions attempt to construct a not-completely-useless SrcSpan from their components, compared with the nl* functions below which just attach noSrcSpan to everything. -} mkHsPar :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) mkHsPar e = cL (getLoc e) (HsPar noExt e) mkSimpleMatch :: HsMatchContext (NameOrRdrName (IdP (GhcPass p))) -> [LPat (GhcPass p)] -> Located (body (GhcPass p)) -> LMatch (GhcPass p) (Located (body (GhcPass p))) mkSimpleMatch ctxt pats rhs = cL loc $ Match { m_ext = noExt, m_ctxt = ctxt, m_pats = pats , m_grhss = unguardedGRHSs rhs } where loc = case pats of [] -> getLoc rhs (pat:_) -> combineSrcSpans (getLoc pat) (getLoc rhs) unguardedGRHSs :: Located (body (GhcPass p)) -> GRHSs (GhcPass p) (Located (body (GhcPass p))) unguardedGRHSs rhs@(dL->L loc _) = GRHSs noExt (unguardedRHS loc rhs) (noLoc emptyLocalBinds) unguardedRHS :: SrcSpan -> Located (body (GhcPass p)) -> [LGRHS (GhcPass p) (Located (body (GhcPass p)))] unguardedRHS loc rhs = [cL loc (GRHS noExt [] rhs)] mkMatchGroup :: (XMG name (Located (body name)) ~ NoExt) => Origin -> [LMatch name (Located (body name))] -> MatchGroup name (Located (body name)) mkMatchGroup origin matches = MG { mg_ext = noExt , mg_alts = mkLocatedList matches , mg_origin = origin } mkLocatedList :: [Located a] -> Located [Located a] mkLocatedList [] = noLoc [] mkLocatedList ms = cL (combineLocs (head ms) (last ms)) ms mkHsApp :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) mkHsApp e1 e2 = addCLoc e1 e2 (HsApp noExt e1 e2) mkHsAppType :: (NoGhcTc (GhcPass id) ~ GhcRn) => LHsExpr (GhcPass id) -> LHsWcType GhcRn -> LHsExpr (GhcPass id) mkHsAppType e t = addCLoc e t_body (HsAppType noExt e paren_wct) where t_body = hswc_body t paren_wct = t { hswc_body = parenthesizeHsType appPrec t_body } mkHsAppTypes :: LHsExpr GhcRn -> [LHsWcType GhcRn] -> LHsExpr GhcRn mkHsAppTypes = foldl' mkHsAppType mkHsLam :: (XMG (GhcPass p) (LHsExpr (GhcPass p)) ~ NoExt) => [LPat (GhcPass p)] -> LHsExpr (GhcPass p) -> LHsExpr (GhcPass p) mkHsLam pats body = mkHsPar (cL (getLoc body) (HsLam noExt matches)) where matches = mkMatchGroup Generated [mkSimpleMatch LambdaExpr pats' body] pats' = map (parenthesizePat appPrec) pats mkHsLams :: [TyVar] -> [EvVar] -> LHsExpr GhcTc -> LHsExpr GhcTc mkHsLams tyvars dicts expr = mkLHsWrap (mkWpTyLams tyvars <.> mkWpLams dicts) expr -- |A simple case alternative with a single pattern, no binds, no guards; -- pre-typechecking mkHsCaseAlt :: LPat (GhcPass p) -> (Located (body (GhcPass p))) -> LMatch (GhcPass p) (Located (body (GhcPass p))) mkHsCaseAlt pat expr = mkSimpleMatch CaseAlt [pat] expr nlHsTyApp :: IdP (GhcPass id) -> [Type] -> LHsExpr (GhcPass id) nlHsTyApp fun_id tys = noLoc (mkHsWrap (mkWpTyApps tys) (HsVar noExt (noLoc fun_id))) nlHsTyApps :: IdP (GhcPass id) -> [Type] -> [LHsExpr (GhcPass id)] -> LHsExpr (GhcPass id) nlHsTyApps fun_id tys xs = foldl' nlHsApp (nlHsTyApp fun_id tys) xs --------- Adding parens --------- mkLHsPar :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -- Wrap in parens if (hsExprNeedsParens appPrec) says it needs them -- So 'f x' becomes '(f x)', but '3' stays as '3' mkLHsPar le@(dL->L loc e) | hsExprNeedsParens appPrec e = cL loc (HsPar noExt le) | otherwise = le mkParPat :: LPat (GhcPass name) -> LPat (GhcPass name) mkParPat lp@(dL->L loc p) | patNeedsParens appPrec p = cL loc (ParPat noExt lp) | otherwise = lp nlParPat :: LPat (GhcPass name) -> LPat (GhcPass name) nlParPat p = noLoc (ParPat noExt p) ------------------------------- -- These are the bits of syntax that contain rebindable names -- See RnEnv.lookupSyntaxName mkHsIntegral :: IntegralLit -> HsOverLit GhcPs mkHsFractional :: FractionalLit -> HsOverLit GhcPs mkHsIsString :: SourceText -> FastString -> HsOverLit GhcPs mkHsDo :: HsStmtContext Name -> [ExprLStmt GhcPs] -> HsExpr GhcPs mkHsComp :: HsStmtContext Name -> [ExprLStmt GhcPs] -> LHsExpr GhcPs -> HsExpr GhcPs mkNPat :: Located (HsOverLit GhcPs) -> Maybe (SyntaxExpr GhcPs) -> Pat GhcPs mkNPlusKPat :: Located RdrName -> Located (HsOverLit GhcPs) -> Pat GhcPs mkLastStmt :: Located (bodyR (GhcPass idR)) -> StmtLR (GhcPass idL) (GhcPass idR) (Located (bodyR (GhcPass idR))) mkBodyStmt :: Located (bodyR GhcPs) -> StmtLR (GhcPass idL) GhcPs (Located (bodyR GhcPs)) mkBindStmt :: (XBindStmt (GhcPass idL) (GhcPass idR) (Located (bodyR (GhcPass idR))) ~ NoExt) => LPat (GhcPass idL) -> Located (bodyR (GhcPass idR)) -> StmtLR (GhcPass idL) (GhcPass idR) (Located (bodyR (GhcPass idR))) mkTcBindStmt :: LPat GhcTc -> Located (bodyR GhcTc) -> StmtLR GhcTc GhcTc (Located (bodyR GhcTc)) emptyRecStmt :: StmtLR (GhcPass idL) GhcPs bodyR emptyRecStmtName :: StmtLR GhcRn GhcRn bodyR emptyRecStmtId :: StmtLR GhcTc GhcTc bodyR mkRecStmt :: [LStmtLR (GhcPass idL) GhcPs bodyR] -> StmtLR (GhcPass idL) GhcPs bodyR mkHsIntegral i = OverLit noExt (HsIntegral i) noExpr mkHsFractional f = OverLit noExt (HsFractional f) noExpr mkHsIsString src s = OverLit noExt (HsIsString src s) noExpr mkHsDo ctxt stmts = HsDo noExt ctxt (mkLocatedList stmts) mkHsComp ctxt stmts expr = mkHsDo ctxt (stmts ++ [last_stmt]) where last_stmt = cL (getLoc expr) $ mkLastStmt expr mkHsIf :: LHsExpr (GhcPass p) -> LHsExpr (GhcPass p) -> LHsExpr (GhcPass p) -> HsExpr (GhcPass p) mkHsIf c a b = HsIf noExt (Just noSyntaxExpr) c a b mkNPat lit neg = NPat noExt lit neg noSyntaxExpr mkNPlusKPat id lit = NPlusKPat noExt id lit (unLoc lit) noSyntaxExpr noSyntaxExpr mkTransformStmt :: [ExprLStmt GhcPs] -> LHsExpr GhcPs -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) mkTransformByStmt :: [ExprLStmt GhcPs] -> LHsExpr GhcPs -> LHsExpr GhcPs -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) mkGroupUsingStmt :: [ExprLStmt GhcPs] -> LHsExpr GhcPs -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) mkGroupByUsingStmt :: [ExprLStmt GhcPs] -> LHsExpr GhcPs -> LHsExpr GhcPs -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) emptyTransStmt :: StmtLR GhcPs GhcPs (LHsExpr GhcPs) emptyTransStmt = TransStmt { trS_ext = noExt , trS_form = panic "emptyTransStmt: form" , trS_stmts = [], trS_bndrs = [] , trS_by = Nothing, trS_using = noLoc noExpr , trS_ret = noSyntaxExpr, trS_bind = noSyntaxExpr , trS_fmap = noExpr } mkTransformStmt ss u = emptyTransStmt { trS_form = ThenForm, trS_stmts = ss, trS_using = u } mkTransformByStmt ss u b = emptyTransStmt { trS_form = ThenForm, trS_stmts = ss, trS_using = u, trS_by = Just b } mkGroupUsingStmt ss u = emptyTransStmt { trS_form = GroupForm, trS_stmts = ss, trS_using = u } mkGroupByUsingStmt ss b u = emptyTransStmt { trS_form = GroupForm, trS_stmts = ss, trS_using = u, trS_by = Just b } mkLastStmt body = LastStmt noExt body False noSyntaxExpr mkBodyStmt body = BodyStmt noExt body noSyntaxExpr noSyntaxExpr mkBindStmt pat body = BindStmt noExt pat body noSyntaxExpr noSyntaxExpr mkTcBindStmt pat body = BindStmt unitTy pat body noSyntaxExpr noSyntaxExpr -- don't use placeHolderTypeTc above, because that panics during zonking emptyRecStmt' :: forall idL idR body. XRecStmt (GhcPass idL) (GhcPass idR) body -> StmtLR (GhcPass idL) (GhcPass idR) body emptyRecStmt' tyVal = RecStmt { recS_stmts = [], recS_later_ids = [] , recS_rec_ids = [] , recS_ret_fn = noSyntaxExpr , recS_mfix_fn = noSyntaxExpr , recS_bind_fn = noSyntaxExpr , recS_ext = tyVal } unitRecStmtTc :: RecStmtTc unitRecStmtTc = RecStmtTc { recS_bind_ty = unitTy , recS_later_rets = [] , recS_rec_rets = [] , recS_ret_ty = unitTy } emptyRecStmt = emptyRecStmt' noExt emptyRecStmtName = emptyRecStmt' noExt emptyRecStmtId = emptyRecStmt' unitRecStmtTc -- a panic might trigger during zonking mkRecStmt stmts = emptyRecStmt { recS_stmts = stmts } ------------------------------- --- A useful function for building @OpApps@. The operator is always a -- variable, and we don't know the fixity yet. mkHsOpApp :: LHsExpr GhcPs -> IdP GhcPs -> LHsExpr GhcPs -> HsExpr GhcPs mkHsOpApp e1 op e2 = OpApp noExt e1 (noLoc (HsVar noExt (noLoc op))) e2 unqualSplice :: RdrName unqualSplice = mkRdrUnqual (mkVarOccFS (fsLit "splice")) mkUntypedSplice :: SpliceDecoration -> LHsExpr GhcPs -> HsSplice GhcPs mkUntypedSplice hasParen e = HsUntypedSplice noExt hasParen unqualSplice e mkHsSpliceE :: SpliceDecoration -> LHsExpr GhcPs -> HsExpr GhcPs mkHsSpliceE hasParen e = HsSpliceE noExt (mkUntypedSplice hasParen e) mkHsSpliceTE :: SpliceDecoration -> LHsExpr GhcPs -> HsExpr GhcPs mkHsSpliceTE hasParen e = HsSpliceE noExt (HsTypedSplice noExt hasParen unqualSplice e) mkHsSpliceTy :: SpliceDecoration -> LHsExpr GhcPs -> HsType GhcPs mkHsSpliceTy hasParen e = HsSpliceTy noExt (HsUntypedSplice noExt hasParen unqualSplice e) mkHsQuasiQuote :: RdrName -> SrcSpan -> FastString -> HsSplice GhcPs mkHsQuasiQuote quoter span quote = HsQuasiQuote noExt unqualSplice quoter span quote unqualQuasiQuote :: RdrName unqualQuasiQuote = mkRdrUnqual (mkVarOccFS (fsLit "quasiquote")) -- A name (uniquified later) to -- identify the quasi-quote mkHsString :: String -> HsLit (GhcPass p) mkHsString s = HsString NoSourceText (mkFastString s) mkHsStringPrimLit :: FastString -> HsLit (GhcPass p) mkHsStringPrimLit fs = HsStringPrim NoSourceText (fastStringToByteString fs) ------------- userHsLTyVarBndrs :: SrcSpan -> [Located (IdP (GhcPass p))] -> [LHsTyVarBndr (GhcPass p)] -- Caller sets location userHsLTyVarBndrs loc bndrs = [ cL loc (UserTyVar noExt v) | v <- bndrs ] userHsTyVarBndrs :: SrcSpan -> [IdP (GhcPass p)] -> [LHsTyVarBndr (GhcPass p)] -- Caller sets location userHsTyVarBndrs loc bndrs = [ cL loc (UserTyVar noExt (cL loc v)) | v <- bndrs ] {- ************************************************************************ * * Constructing syntax with no location info * * ************************************************************************ -} nlHsVar :: IdP (GhcPass id) -> LHsExpr (GhcPass id) nlHsVar n = noLoc (HsVar noExt (noLoc n)) -- NB: Only for LHsExpr **Id** nlHsDataCon :: DataCon -> LHsExpr GhcTc nlHsDataCon con = noLoc (HsConLikeOut noExt (RealDataCon con)) nlHsLit :: HsLit (GhcPass p) -> LHsExpr (GhcPass p) nlHsLit n = noLoc (HsLit noExt n) nlHsIntLit :: Integer -> LHsExpr (GhcPass p) nlHsIntLit n = noLoc (HsLit noExt (HsInt noExt (mkIntegralLit n))) nlVarPat :: IdP (GhcPass id) -> LPat (GhcPass id) nlVarPat n = noLoc (VarPat noExt (noLoc n)) nlLitPat :: HsLit GhcPs -> LPat GhcPs nlLitPat l = noLoc (LitPat noExt l) nlHsApp :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) nlHsApp f x = noLoc (HsApp noExt f (mkLHsPar x)) nlHsSyntaxApps :: SyntaxExpr (GhcPass id) -> [LHsExpr (GhcPass id)] -> LHsExpr (GhcPass id) nlHsSyntaxApps (SyntaxExpr { syn_expr = fun , syn_arg_wraps = arg_wraps , syn_res_wrap = res_wrap }) args | [] <- arg_wraps -- in the noSyntaxExpr case = ASSERT( isIdHsWrapper res_wrap ) foldl' nlHsApp (noLoc fun) args | otherwise = mkLHsWrap res_wrap (foldl' nlHsApp (noLoc fun) (zipWithEqual "nlHsSyntaxApps" mkLHsWrap arg_wraps args)) nlHsApps :: IdP (GhcPass id) -> [LHsExpr (GhcPass id)] -> LHsExpr (GhcPass id) nlHsApps f xs = foldl' nlHsApp (nlHsVar f) xs nlHsVarApps :: IdP (GhcPass id) -> [IdP (GhcPass id)] -> LHsExpr (GhcPass id) nlHsVarApps f xs = noLoc (foldl' mk (HsVar noExt (noLoc f)) (map ((HsVar noExt) . noLoc) xs)) where mk f a = HsApp noExt (noLoc f) (noLoc a) nlConVarPat :: RdrName -> [RdrName] -> LPat GhcPs nlConVarPat con vars = nlConPat con (map nlVarPat vars) nlConVarPatName :: Name -> [Name] -> LPat GhcRn nlConVarPatName con vars = nlConPatName con (map nlVarPat vars) nlInfixConPat :: RdrName -> LPat GhcPs -> LPat GhcPs -> LPat GhcPs nlInfixConPat con l r = noLoc (ConPatIn (noLoc con) (InfixCon (parenthesizePat opPrec l) (parenthesizePat opPrec r))) nlConPat :: RdrName -> [LPat GhcPs] -> LPat GhcPs nlConPat con pats = noLoc (ConPatIn (noLoc con) (PrefixCon (map (parenthesizePat appPrec) pats))) nlConPatName :: Name -> [LPat GhcRn] -> LPat GhcRn nlConPatName con pats = noLoc (ConPatIn (noLoc con) (PrefixCon (map (parenthesizePat appPrec) pats))) nlNullaryConPat :: IdP (GhcPass p) -> LPat (GhcPass p) nlNullaryConPat con = noLoc (ConPatIn (noLoc con) (PrefixCon [])) nlWildConPat :: DataCon -> LPat GhcPs nlWildConPat con = noLoc (ConPatIn (noLoc (getRdrName con)) (PrefixCon (nOfThem (dataConSourceArity con) nlWildPat))) nlWildPat :: LPat GhcPs nlWildPat = noLoc (WildPat noExt ) -- Pre-typechecking nlWildPatName :: LPat GhcRn nlWildPatName = noLoc (WildPat noExt ) -- Pre-typechecking nlHsDo :: HsStmtContext Name -> [LStmt GhcPs (LHsExpr GhcPs)] -> LHsExpr GhcPs nlHsDo ctxt stmts = noLoc (mkHsDo ctxt stmts) nlHsOpApp :: LHsExpr GhcPs -> IdP GhcPs -> LHsExpr GhcPs -> LHsExpr GhcPs nlHsOpApp e1 op e2 = noLoc (mkHsOpApp e1 op e2) nlHsLam :: LMatch GhcPs (LHsExpr GhcPs) -> LHsExpr GhcPs nlHsPar :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) nlHsIf :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) nlHsCase :: LHsExpr GhcPs -> [LMatch GhcPs (LHsExpr GhcPs)] -> LHsExpr GhcPs nlList :: [LHsExpr GhcPs] -> LHsExpr GhcPs nlHsLam match = noLoc (HsLam noExt (mkMatchGroup Generated [match])) nlHsPar e = noLoc (HsPar noExt e) -- Note [Rebindable nlHsIf] -- nlHsIf should generate if-expressions which are NOT subject to -- RebindableSyntax, so the first field of HsIf is Nothing. (#12080) nlHsIf cond true false = noLoc (HsIf noExt Nothing cond true false) nlHsCase expr matches = noLoc (HsCase noExt expr (mkMatchGroup Generated matches)) nlList exprs = noLoc (ExplicitList noExt Nothing exprs) nlHsAppTy :: LHsType (GhcPass p) -> LHsType (GhcPass p) -> LHsType (GhcPass p) nlHsTyVar :: IdP (GhcPass p) -> LHsType (GhcPass p) nlHsFunTy :: LHsType (GhcPass p) -> LHsType (GhcPass p) -> LHsType (GhcPass p) nlHsParTy :: LHsType (GhcPass p) -> LHsType (GhcPass p) nlHsAppTy f t = noLoc (HsAppTy noExt f (parenthesizeHsType appPrec t)) nlHsTyVar x = noLoc (HsTyVar noExt NotPromoted (noLoc x)) nlHsFunTy a b = noLoc (HsFunTy noExt (parenthesizeHsType funPrec a) b) nlHsParTy t = noLoc (HsParTy noExt t) nlHsTyConApp :: IdP (GhcPass p) -> [LHsType (GhcPass p)] -> LHsType (GhcPass p) nlHsTyConApp tycon tys = foldl' nlHsAppTy (nlHsTyVar tycon) tys {- Tuples. All these functions are *pre-typechecker* because they lack types on the tuple. -} mkLHsTupleExpr :: [LHsExpr (GhcPass a)] -> LHsExpr (GhcPass a) -- Makes a pre-typechecker boxed tuple, deals with 1 case mkLHsTupleExpr [e] = e mkLHsTupleExpr es = noLoc $ ExplicitTuple noExt (map (noLoc . (Present noExt)) es) Boxed mkLHsVarTuple :: [IdP (GhcPass a)] -> LHsExpr (GhcPass a) mkLHsVarTuple ids = mkLHsTupleExpr (map nlHsVar ids) nlTuplePat :: [LPat GhcPs] -> Boxity -> LPat GhcPs nlTuplePat pats box = noLoc (TuplePat noExt pats box) missingTupArg :: HsTupArg GhcPs missingTupArg = Missing noExt mkLHsPatTup :: [LPat GhcRn] -> LPat GhcRn mkLHsPatTup [] = noLoc $ TuplePat noExt [] Boxed mkLHsPatTup [lpat] = lpat mkLHsPatTup lpats = cL (getLoc (head lpats)) $ TuplePat noExt lpats Boxed -- The Big equivalents for the source tuple expressions mkBigLHsVarTup :: [IdP (GhcPass id)] -> LHsExpr (GhcPass id) mkBigLHsVarTup ids = mkBigLHsTup (map nlHsVar ids) mkBigLHsTup :: [LHsExpr (GhcPass id)] -> LHsExpr (GhcPass id) mkBigLHsTup = mkChunkified mkLHsTupleExpr -- The Big equivalents for the source tuple patterns mkBigLHsVarPatTup :: [IdP GhcRn] -> LPat GhcRn mkBigLHsVarPatTup bs = mkBigLHsPatTup (map nlVarPat bs) mkBigLHsPatTup :: [LPat GhcRn] -> LPat GhcRn mkBigLHsPatTup = mkChunkified mkLHsPatTup -- $big_tuples -- #big_tuples# -- -- GHCs built in tuples can only go up to 'mAX_TUPLE_SIZE' in arity, but -- we might concievably want to build such a massive tuple as part of the -- output of a desugaring stage (notably that for list comprehensions). -- -- We call tuples above this size \"big tuples\", and emulate them by -- creating and pattern matching on >nested< tuples that are expressible -- by GHC. -- -- Nesting policy: it's better to have a 2-tuple of 10-tuples (3 objects) -- than a 10-tuple of 2-tuples (11 objects), so we want the leaves of any -- construction to be big. -- -- If you just use the 'mkBigCoreTup', 'mkBigCoreVarTupTy', 'mkTupleSelector' -- and 'mkTupleCase' functions to do all your work with tuples you should be -- fine, and not have to worry about the arity limitation at all. -- | Lifts a \"small\" constructor into a \"big\" constructor by recursive decompositon mkChunkified :: ([a] -> a) -- ^ \"Small\" constructor function, of maximum input arity 'mAX_TUPLE_SIZE' -> [a] -- ^ Possible \"big\" list of things to construct from -> a -- ^ Constructed thing made possible by recursive decomposition mkChunkified small_tuple as = mk_big_tuple (chunkify as) where -- Each sub-list is short enough to fit in a tuple mk_big_tuple [as] = small_tuple as mk_big_tuple as_s = mk_big_tuple (chunkify (map small_tuple as_s)) chunkify :: [a] -> [[a]] -- ^ Split a list into lists that are small enough to have a corresponding -- tuple arity. The sub-lists of the result all have length <= 'mAX_TUPLE_SIZE' -- But there may be more than 'mAX_TUPLE_SIZE' sub-lists chunkify xs | n_xs <= mAX_TUPLE_SIZE = [xs] | otherwise = split xs where n_xs = length xs split [] = [] split xs = take mAX_TUPLE_SIZE xs : split (drop mAX_TUPLE_SIZE xs) {- ************************************************************************ * * LHsSigType and LHsSigWcType * * ********************************************************************* -} mkLHsSigType :: LHsType GhcPs -> LHsSigType GhcPs mkLHsSigType ty = mkHsImplicitBndrs ty mkLHsSigWcType :: LHsType GhcPs -> LHsSigWcType GhcPs mkLHsSigWcType ty = mkHsWildCardBndrs (mkHsImplicitBndrs ty) mkHsSigEnv :: forall a. (LSig GhcRn -> Maybe ([Located Name], a)) -> [LSig GhcRn] -> NameEnv a mkHsSigEnv get_info sigs = mkNameEnv (mk_pairs ordinary_sigs) `extendNameEnvList` (mk_pairs gen_dm_sigs) -- The subtlety is this: in a class decl with a -- default-method signature as well as a method signature -- we want the latter to win (Trac #12533) -- class C x where -- op :: forall a . x a -> x a -- default op :: forall b . x b -> x b -- op x = ...(e :: b -> b)... -- The scoped type variables of the 'default op', namely 'b', -- scope over the code for op. The 'forall a' does not! -- This applies both in the renamer and typechecker, both -- of which use this function where (gen_dm_sigs, ordinary_sigs) = partition is_gen_dm_sig sigs is_gen_dm_sig (dL->L _ (ClassOpSig _ True _ _)) = True is_gen_dm_sig _ = False mk_pairs :: [LSig GhcRn] -> [(Name, a)] mk_pairs sigs = [ (n,a) | Just (ns,a) <- map get_info sigs , (dL->L _ n) <- ns ] mkClassOpSigs :: [LSig GhcPs] -> [LSig GhcPs] -- Convert TypeSig to ClassOpSig -- The former is what is parsed, but the latter is -- what we need in class/instance declarations mkClassOpSigs sigs = map fiddle sigs where fiddle (dL->L loc (TypeSig _ nms ty)) = cL loc (ClassOpSig noExt False nms (dropWildCards ty)) fiddle sig = sig typeToLHsType :: Type -> LHsType GhcPs -- ^ Converting a Type to an HsType RdrName -- This is needed to implement GeneralizedNewtypeDeriving. -- -- Note that we use 'getRdrName' extensively, which -- generates Exact RdrNames rather than strings. typeToLHsType ty = go ty where go :: Type -> LHsType GhcPs go ty@(FunTy arg _) | isPredTy arg , (theta, tau) <- tcSplitPhiTy ty = noLoc (HsQualTy { hst_ctxt = noLoc (map go theta) , hst_xqual = noExt , hst_body = go tau }) go (FunTy arg res) = nlHsFunTy (go arg) (go res) go ty@(ForAllTy {}) | (tvs, tau) <- tcSplitForAllTys ty = noLoc (HsForAllTy { hst_bndrs = map go_tv tvs , hst_xforall = noExt , hst_body = go tau }) go (TyVarTy tv) = nlHsTyVar (getRdrName tv) go (AppTy t1 t2) = nlHsAppTy (go t1) (go t2) go (LitTy (NumTyLit n)) = noLoc $ HsTyLit NoExt (HsNumTy NoSourceText n) go (LitTy (StrTyLit s)) = noLoc $ HsTyLit NoExt (HsStrTy NoSourceText s) go ty@(TyConApp tc args) | any isInvisibleTyConBinder (tyConBinders tc) -- We must produce an explicit kind signature here to make certain -- programs kind-check. See Note [Kind signatures in typeToLHsType]. = nlHsParTy $ noLoc $ HsKindSig NoExt lhs_ty (go (typeKind ty)) | otherwise = lhs_ty where lhs_ty = nlHsTyConApp (getRdrName tc) (map go args') args' = filterOutInvisibleTypes tc args go (CastTy ty _) = go ty go (CoercionTy co) = pprPanic "toLHsSigWcType" (ppr co) -- Source-language types have _invisible_ kind arguments, -- so we must remove them here (Trac #8563) go_tv :: TyVar -> LHsTyVarBndr GhcPs go_tv tv = noLoc $ KindedTyVar noExt (noLoc (getRdrName tv)) (go (tyVarKind tv)) {- Note [Kind signatures in typeToLHsType] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ There are types that typeToLHsType can produce which require explicit kind signatures in order to kind-check. Here is an example from Trac #14579: newtype Wat (x :: Proxy (a :: Type)) = MkWat (Maybe a) deriving Eq newtype Glurp a = MkGlurp (Wat ('Proxy :: Proxy a)) deriving Eq The derived Eq instance for Glurp (without any kind signatures) would be: instance Eq a => Eq (Glurp a) where (==) = coerce @(Wat 'Proxy -> Wat 'Proxy -> Bool) @(Glurp a -> Glurp a -> Bool) (==) :: Glurp a -> Glurp a -> Bool (Where the visible type applications use types produced by typeToLHsType.) The type 'Proxy has an underspecified kind, so we must ensure that typeToLHsType ascribes it with its kind: ('Proxy :: Proxy a). We must be careful not to produce too many kind signatures, or else typeToLHsType can produce noisy types like ('Proxy :: Proxy (a :: (Type :: Type))). In pursuit of this goal, we adopt the following criterion for choosing when to annotate types with kinds: * If there is a tycon application with any invisible arguments, annotate the tycon application with its kind. Why is this the right criterion? The problem we encountered earlier was the result of an invisible argument (the `a` in ('Proxy :: Proxy a)) being underspecified, so producing a kind signature for 'Proxy will catch this. If there are no invisible arguments, then there is nothing to do, so we can avoid polluting the result type with redundant noise. What about a more complicated tycon, such as this? T :: forall {j} (a :: j). a -> Type Unlike in the previous 'Proxy example, annotating an application of `T` to an argument (e.g., annotating T ty to obtain (T ty :: Type)) will not fix its invisible argument `j`. But because we apply this strategy recursively, `j` will be fixed because the kind of `ty` will be fixed! That is to say, something to the effect of (T (ty :: j) :: Type) will be produced. This strategy certainly isn't foolproof, as tycons that contain type families in their kind might break down. But we'd likely need visible kind application to make those work. -} {- ********************************************************************* * * --------- HsWrappers: type args, dict args, casts --------- * * ********************************************************************* -} mkLHsWrap :: HsWrapper -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) mkLHsWrap co_fn (dL->L loc e) = cL loc (mkHsWrap co_fn e) -- Avoid (HsWrap co (HsWrap co' _)). -- See Note [Detecting forced eta expansion] in DsExpr mkHsWrap :: HsWrapper -> HsExpr (GhcPass id) -> HsExpr (GhcPass id) mkHsWrap co_fn e | isIdHsWrapper co_fn = e mkHsWrap co_fn (HsWrap _ co_fn' e) = mkHsWrap (co_fn <.> co_fn') e mkHsWrap co_fn e = HsWrap noExt co_fn e mkHsWrapCo :: TcCoercionN -- A Nominal coercion a ~N b -> HsExpr (GhcPass id) -> HsExpr (GhcPass id) mkHsWrapCo co e = mkHsWrap (mkWpCastN co) e mkHsWrapCoR :: TcCoercionR -- A Representational coercion a ~R b -> HsExpr (GhcPass id) -> HsExpr (GhcPass id) mkHsWrapCoR co e = mkHsWrap (mkWpCastR co) e mkLHsWrapCo :: TcCoercionN -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) mkLHsWrapCo co (dL->L loc e) = cL loc (mkHsWrapCo co e) mkHsCmdWrap :: HsWrapper -> HsCmd (GhcPass p) -> HsCmd (GhcPass p) mkHsCmdWrap w cmd | isIdHsWrapper w = cmd | otherwise = HsCmdWrap noExt w cmd mkLHsCmdWrap :: HsWrapper -> LHsCmd (GhcPass p) -> LHsCmd (GhcPass p) mkLHsCmdWrap w (dL->L loc c) = cL loc (mkHsCmdWrap w c) mkHsWrapPat :: HsWrapper -> Pat (GhcPass id) -> Type -> Pat (GhcPass id) mkHsWrapPat co_fn p ty | isIdHsWrapper co_fn = p | otherwise = CoPat noExt co_fn p ty mkHsWrapPatCo :: TcCoercionN -> Pat (GhcPass id) -> Type -> Pat (GhcPass id) mkHsWrapPatCo co pat ty | isTcReflCo co = pat | otherwise = CoPat noExt (mkWpCastN co) pat ty mkHsDictLet :: TcEvBinds -> LHsExpr GhcTc -> LHsExpr GhcTc mkHsDictLet ev_binds expr = mkLHsWrap (mkWpLet ev_binds) expr {- l ************************************************************************ * * Bindings; with a location at the top * * ************************************************************************ -} mkFunBind :: Located RdrName -> [LMatch GhcPs (LHsExpr GhcPs)] -> HsBind GhcPs -- Not infix, with place holders for coercion and free vars mkFunBind fn ms = FunBind { fun_id = fn , fun_matches = mkMatchGroup Generated ms , fun_co_fn = idHsWrapper , fun_ext = noExt , fun_tick = [] } mkTopFunBind :: Origin -> Located Name -> [LMatch GhcRn (LHsExpr GhcRn)] -> HsBind GhcRn -- In Name-land, with empty bind_fvs mkTopFunBind origin fn ms = FunBind { fun_id = fn , fun_matches = mkMatchGroup origin ms , fun_co_fn = idHsWrapper , fun_ext = emptyNameSet -- NB: closed -- binding , fun_tick = [] } mkHsVarBind :: SrcSpan -> RdrName -> LHsExpr GhcPs -> LHsBind GhcPs mkHsVarBind loc var rhs = mk_easy_FunBind loc var [] rhs mkVarBind :: IdP (GhcPass p) -> LHsExpr (GhcPass p) -> LHsBind (GhcPass p) mkVarBind var rhs = cL (getLoc rhs) $ VarBind { var_ext = noExt, var_id = var, var_rhs = rhs, var_inline = False } mkPatSynBind :: Located RdrName -> HsPatSynDetails (Located RdrName) -> LPat GhcPs -> HsPatSynDir GhcPs -> HsBind GhcPs mkPatSynBind name details lpat dir = PatSynBind noExt psb where psb = PSB{ psb_ext = noExt , psb_id = name , psb_args = details , psb_def = lpat , psb_dir = dir } -- |If any of the matches in the 'FunBind' are infix, the 'FunBind' is -- considered infix. isInfixFunBind :: HsBindLR id1 id2 -> Bool isInfixFunBind (FunBind _ _ (MG _ matches _) _ _) = any (isInfixMatch . unLoc) (unLoc matches) isInfixFunBind _ = False ------------ mk_easy_FunBind :: SrcSpan -> RdrName -> [LPat GhcPs] -> LHsExpr GhcPs -> LHsBind GhcPs mk_easy_FunBind loc fun pats expr = cL loc $ mkFunBind (cL loc fun) [mkMatch (mkPrefixFunRhs (cL loc fun)) pats expr (noLoc emptyLocalBinds)] -- | Make a prefix, non-strict function 'HsMatchContext' mkPrefixFunRhs :: Located id -> HsMatchContext id mkPrefixFunRhs n = FunRhs { mc_fun = n , mc_fixity = Prefix , mc_strictness = NoSrcStrict } ------------ mkMatch :: HsMatchContext (NameOrRdrName (IdP (GhcPass p))) -> [LPat (GhcPass p)] -> LHsExpr (GhcPass p) -> Located (HsLocalBinds (GhcPass p)) -> LMatch (GhcPass p) (LHsExpr (GhcPass p)) mkMatch ctxt pats expr lbinds = noLoc (Match { m_ext = noExt , m_ctxt = ctxt , m_pats = map paren pats , m_grhss = GRHSs noExt (unguardedRHS noSrcSpan expr) lbinds }) where paren lp@(dL->L l p) | patNeedsParens appPrec p = cL l (ParPat noExt lp) | otherwise = lp {- ************************************************************************ * * Collecting binders * * ************************************************************************ Get all the binders in some HsBindGroups, IN THE ORDER OF APPEARANCE. eg. ... where (x, y) = ... f i j = ... [a, b] = ... it should return [x, y, f, a, b] (remember, order important). Note [Collect binders only after renaming] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ These functions should only be used on HsSyn *after* the renamer, to return a [Name] or [Id]. Before renaming the record punning and wild-card mechanism makes it hard to know what is bound. So these functions should not be applied to (HsSyn RdrName) Note [Unlifted id check in isUnliftedHsBind] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The function isUnliftedHsBind is used to complain if we make a top-level binding for a variable of unlifted type. Such a binding is illegal if the top-level binding would be unlifted; but also if the local letrec generated by desugaring AbsBinds would be. E.g. f :: Num a => (# a, a #) g :: Num a => a -> a f = ...g... g = ...g... The top-level bindings for f,g are not unlifted (because of the Num a =>), but the local, recursive, monomorphic bindings are: t = /\a \(d:Num a). letrec fm :: (# a, a #) = ...g... gm :: a -> a = ...f... in (fm, gm) Here the binding for 'fm' is illegal. So generally we check the abe_mono types. BUT we have a special case when abs_sig is true; see HsBinds Note [The abs_sig field of AbsBinds] -} ----------------- Bindings -------------------------- -- | Should we treat this as an unlifted bind? This will be true for any -- bind that binds an unlifted variable, but we must be careful around -- AbsBinds. See Note [Unlifted id check in isUnliftedHsBind]. For usage -- information, see Note [Strict binds check] is DsBinds. isUnliftedHsBind :: HsBind GhcTc -> Bool -- works only over typechecked binds isUnliftedHsBind bind | AbsBinds { abs_exports = exports, abs_sig = has_sig } <- bind = if has_sig then any (is_unlifted_id . abe_poly) exports else any (is_unlifted_id . abe_mono) exports -- If has_sig is True we wil never generate a binding for abe_mono, -- so we don't need to worry about it being unlifted. The abe_poly -- binding might not be: e.g. forall a. Num a => (# a, a #) | otherwise = any is_unlifted_id (collectHsBindBinders bind) where is_unlifted_id id = isUnliftedType (idType id) -- | Is a binding a strict variable or pattern bind (e.g. @!x = ...@)? isBangedHsBind :: HsBind GhcTc -> Bool isBangedHsBind (AbsBinds { abs_binds = binds }) = anyBag (isBangedHsBind . unLoc) binds isBangedHsBind (FunBind {fun_matches = matches}) | [dL->L _ match] <- unLoc $ mg_alts matches , FunRhs{mc_strictness = SrcStrict} <- m_ctxt match = True isBangedHsBind (PatBind {pat_lhs = pat}) = isBangedLPat pat isBangedHsBind _ = False collectLocalBinders :: HsLocalBindsLR (GhcPass idL) (GhcPass idR) -> [IdP (GhcPass idL)] collectLocalBinders (HsValBinds _ binds) = collectHsIdBinders binds -- No pattern synonyms here collectLocalBinders (HsIPBinds {}) = [] collectLocalBinders (EmptyLocalBinds _) = [] collectLocalBinders (XHsLocalBindsLR _) = [] collectHsIdBinders, collectHsValBinders :: HsValBindsLR (GhcPass idL) (GhcPass idR) -> [IdP (GhcPass idL)] -- Collect Id binders only, or Ids + pattern synonyms, respectively collectHsIdBinders = collect_hs_val_binders True collectHsValBinders = collect_hs_val_binders False collectHsBindBinders :: (SrcSpanLess (LPat p) ~ Pat p, HasSrcSpan (LPat p))=> HsBindLR p idR -> [IdP p] -- Collect both Ids and pattern-synonym binders collectHsBindBinders b = collect_bind False b [] collectHsBindsBinders :: LHsBindsLR (GhcPass p) idR -> [IdP (GhcPass p)] collectHsBindsBinders binds = collect_binds False binds [] collectHsBindListBinders :: [LHsBindLR (GhcPass p) idR] -> [IdP (GhcPass p)] -- Same as collectHsBindsBinders, but works over a list of bindings collectHsBindListBinders = foldr (collect_bind False . unLoc) [] collect_hs_val_binders :: Bool -> HsValBindsLR (GhcPass idL) (GhcPass idR) -> [IdP (GhcPass idL)] collect_hs_val_binders ps (ValBinds _ binds _) = collect_binds ps binds [] collect_hs_val_binders ps (XValBindsLR (NValBinds binds _)) = collect_out_binds ps binds collect_out_binds :: Bool -> [(RecFlag, LHsBinds (GhcPass p))] -> [IdP (GhcPass p)] collect_out_binds ps = foldr (collect_binds ps . snd) [] collect_binds :: Bool -> LHsBindsLR (GhcPass p) idR -> [IdP (GhcPass p)] -> [IdP (GhcPass p)] -- Collect Ids, or Ids + pattern synonyms, depending on boolean flag collect_binds ps binds acc = foldrBag (collect_bind ps . unLoc) acc binds collect_bind :: (SrcSpanLess (LPat p) ~ Pat p , HasSrcSpan (LPat p)) => Bool -> HsBindLR p idR -> [IdP p] -> [IdP p] collect_bind _ (PatBind { pat_lhs = p }) acc = collect_lpat p acc collect_bind _ (FunBind { fun_id = (dL->L _ f) }) acc = f : acc collect_bind _ (VarBind { var_id = f }) acc = f : acc collect_bind _ (AbsBinds { abs_exports = dbinds }) acc = map abe_poly dbinds ++ acc -- I don't think we want the binders from the abe_binds -- binding (hence see AbsBinds) is in zonking in TcHsSyn collect_bind omitPatSyn (PatSynBind _ (PSB { psb_id = (dL->L _ ps) })) acc | omitPatSyn = acc | otherwise = ps : acc collect_bind _ (PatSynBind _ (XPatSynBind _)) acc = acc collect_bind _ (XHsBindsLR _) acc = acc collectMethodBinders :: LHsBindsLR idL idR -> [Located (IdP idL)] -- Used exclusively for the bindings of an instance decl which are all FunBinds collectMethodBinders binds = foldrBag (get . unLoc) [] binds where get (FunBind { fun_id = f }) fs = f : fs get _ fs = fs -- Someone else complains about non-FunBinds ----------------- Statements -------------------------- collectLStmtsBinders :: [LStmtLR (GhcPass idL) (GhcPass idR) body] -> [IdP (GhcPass idL)] collectLStmtsBinders = concatMap collectLStmtBinders collectStmtsBinders :: [StmtLR (GhcPass idL) (GhcPass idR) body] -> [IdP (GhcPass idL)] collectStmtsBinders = concatMap collectStmtBinders collectLStmtBinders :: LStmtLR (GhcPass idL) (GhcPass idR) body -> [IdP (GhcPass idL)] collectLStmtBinders = collectStmtBinders . unLoc collectStmtBinders :: StmtLR (GhcPass idL) (GhcPass idR) body -> [IdP (GhcPass idL)] -- Id Binders for a Stmt... [but what about pattern-sig type vars]? collectStmtBinders (BindStmt _ pat _ _ _) = collectPatBinders pat collectStmtBinders (LetStmt _ binds) = collectLocalBinders (unLoc binds) collectStmtBinders (BodyStmt {}) = [] collectStmtBinders (LastStmt {}) = [] collectStmtBinders (ParStmt _ xs _ _) = collectLStmtsBinders $ [s | ParStmtBlock _ ss _ _ <- xs, s <- ss] collectStmtBinders (TransStmt { trS_stmts = stmts }) = collectLStmtsBinders stmts collectStmtBinders (RecStmt { recS_stmts = ss }) = collectLStmtsBinders ss collectStmtBinders (ApplicativeStmt _ args _) = concatMap collectArgBinders args where collectArgBinders (_, ApplicativeArgOne _ pat _ _) = collectPatBinders pat collectArgBinders (_, ApplicativeArgMany _ _ _ pat) = collectPatBinders pat collectArgBinders _ = [] collectStmtBinders XStmtLR{} = panic "collectStmtBinders" ----------------- Patterns -------------------------- collectPatBinders :: LPat (GhcPass p) -> [IdP (GhcPass p)] collectPatBinders pat = collect_lpat pat [] collectPatsBinders :: [LPat (GhcPass p)] -> [IdP (GhcPass p)] collectPatsBinders pats = foldr collect_lpat [] pats ------------- collect_lpat :: (SrcSpanLess (LPat p) ~ Pat p , HasSrcSpan (LPat p)) => LPat p -> [IdP p] -> [IdP p] collect_lpat p bndrs = go (unLoc p) where go (VarPat _ var) = unLoc var : bndrs go (WildPat _) = bndrs go (LazyPat _ pat) = collect_lpat pat bndrs go (BangPat _ pat) = collect_lpat pat bndrs go (AsPat _ a pat) = unLoc a : collect_lpat pat bndrs go (ViewPat _ _ pat) = collect_lpat pat bndrs go (ParPat _ pat) = collect_lpat pat bndrs go (ListPat _ pats) = foldr collect_lpat bndrs pats go (TuplePat _ pats _) = foldr collect_lpat bndrs pats go (SumPat _ pat _ _) = collect_lpat pat bndrs go (ConPatIn _ ps) = foldr collect_lpat bndrs (hsConPatArgs ps) go (ConPatOut {pat_args=ps}) = foldr collect_lpat bndrs (hsConPatArgs ps) -- See Note [Dictionary binders in ConPatOut] go (LitPat _ _) = bndrs go (NPat {}) = bndrs go (NPlusKPat _ n _ _ _ _) = unLoc n : bndrs go (SigPat _ pat _) = collect_lpat pat bndrs go (SplicePat _ (HsSpliced _ _ (HsSplicedPat pat))) = go pat go (SplicePat _ _) = bndrs go (CoPat _ _ pat _) = go pat go (XPat {}) = bndrs {- Note [Dictionary binders in ConPatOut] See also same Note in DsArrows ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Do *not* gather (a) dictionary and (b) dictionary bindings as binders of a ConPatOut pattern. For most calls it doesn't matter, because it's pre-typechecker and there are no ConPatOuts. But it does matter more in the desugarer; for example, DsUtils.mkSelectorBinds uses collectPatBinders. In a lazy pattern, for example f ~(C x y) = ..., we want to generate bindings for x,y but not for dictionaries bound by C. (The type checker ensures they would not be used.) Desugaring of arrow case expressions needs these bindings (see DsArrows and arrowcase1), but SPJ (Jan 2007) says it's safer for it to use its own pat-binder-collector: Here's the problem. Consider data T a where C :: Num a => a -> Int -> T a f ~(C (n+1) m) = (n,m) Here, the pattern (C (n+1)) binds a hidden dictionary (d::Num a), and *also* uses that dictionary to match the (n+1) pattern. Yet, the variables bound by the lazy pattern are n,m, *not* the dictionary d. So in mkSelectorBinds in DsUtils, we want just m,n as the variables bound. -} hsGroupBinders :: HsGroup GhcRn -> [Name] hsGroupBinders (HsGroup { hs_valds = val_decls, hs_tyclds = tycl_decls, hs_fords = foreign_decls }) = collectHsValBinders val_decls ++ hsTyClForeignBinders tycl_decls foreign_decls hsGroupBinders (XHsGroup {}) = panic "hsGroupBinders" hsTyClForeignBinders :: [TyClGroup GhcRn] -> [LForeignDecl GhcRn] -> [Name] -- We need to look at instance declarations too, -- because their associated types may bind data constructors hsTyClForeignBinders tycl_decls foreign_decls = map unLoc (hsForeignDeclsBinders foreign_decls) ++ getSelectorNames (foldMap (foldMap hsLTyClDeclBinders . group_tyclds) tycl_decls `mappend` foldMap (foldMap hsLInstDeclBinders . group_instds) tycl_decls) where getSelectorNames :: ([Located Name], [LFieldOcc GhcRn]) -> [Name] getSelectorNames (ns, fs) = map unLoc ns ++ map (extFieldOcc . unLoc) fs ------------------- hsLTyClDeclBinders :: Located (TyClDecl pass) -> ([Located (IdP pass)], [LFieldOcc pass]) -- ^ Returns all the /binding/ names of the decl. The first one is -- guaranteed to be the name of the decl. The first component -- represents all binding names except record fields; the second -- represents field occurrences. For record fields mentioned in -- multiple constructors, the SrcLoc will be from the first occurrence. -- -- Each returned (Located name) has a SrcSpan for the /whole/ declaration. -- See Note [SrcSpan for binders] hsLTyClDeclBinders (dL->L loc (FamDecl { tcdFam = FamilyDecl { fdLName = (dL->L _ name) } })) = ([cL loc name], []) hsLTyClDeclBinders (dL->L _ (FamDecl { tcdFam = XFamilyDecl _ })) = panic "hsLTyClDeclBinders" hsLTyClDeclBinders (dL->L loc (SynDecl { tcdLName = (dL->L _ name) })) = ([cL loc name], []) hsLTyClDeclBinders (dL->L loc (ClassDecl { tcdLName = (dL->L _ cls_name) , tcdSigs = sigs , tcdATs = ats })) = (cL loc cls_name : [ cL fam_loc fam_name | (dL->L fam_loc (FamilyDecl { fdLName = L _ fam_name })) <- ats ] ++ [ cL mem_loc mem_name | (dL->L mem_loc (ClassOpSig _ False ns _)) <- sigs , (dL->L _ mem_name) <- ns ] , []) hsLTyClDeclBinders (dL->L loc (DataDecl { tcdLName = (dL->L _ name) , tcdDataDefn = defn })) = (\ (xs, ys) -> (cL loc name : xs, ys)) $ hsDataDefnBinders defn hsLTyClDeclBinders (dL->L _ (XTyClDecl _)) = panic "hsLTyClDeclBinders" hsLTyClDeclBinders _ = panic "hsLTyClDeclBinders: Impossible Match" -- due to #15884 ------------------- hsForeignDeclsBinders :: [LForeignDecl pass] -> [Located (IdP pass)] -- See Note [SrcSpan for binders] hsForeignDeclsBinders foreign_decls = [ cL decl_loc n | (dL->L decl_loc (ForeignImport { fd_name = (dL->L _ n) })) <- foreign_decls] ------------------- hsPatSynSelectors :: HsValBinds (GhcPass p) -> [IdP (GhcPass p)] -- Collects record pattern-synonym selectors only; the pattern synonym -- names are collected by collectHsValBinders. hsPatSynSelectors (ValBinds _ _ _) = panic "hsPatSynSelectors" hsPatSynSelectors (XValBindsLR (NValBinds binds _)) = foldrBag addPatSynSelector [] . unionManyBags $ map snd binds addPatSynSelector:: LHsBind p -> [IdP p] -> [IdP p] addPatSynSelector bind sels | PatSynBind _ (PSB { psb_args = RecCon as }) <- unLoc bind = map (unLoc . recordPatSynSelectorId) as ++ sels | otherwise = sels getPatSynBinds :: [(RecFlag, LHsBinds id)] -> [PatSynBind id id] getPatSynBinds binds = [ psb | (_, lbinds) <- binds , (dL->L _ (PatSynBind _ psb)) <- bagToList lbinds ] ------------------- hsLInstDeclBinders :: LInstDecl (GhcPass p) -> ([Located (IdP (GhcPass p))], [LFieldOcc (GhcPass p)]) hsLInstDeclBinders (dL->L _ (ClsInstD { cid_inst = ClsInstDecl { cid_datafam_insts = dfis }})) = foldMap (hsDataFamInstBinders . unLoc) dfis hsLInstDeclBinders (dL->L _ (DataFamInstD { dfid_inst = fi })) = hsDataFamInstBinders fi hsLInstDeclBinders (dL->L _ (TyFamInstD {})) = mempty hsLInstDeclBinders (dL->L _ (ClsInstD _ (XClsInstDecl {}))) = panic "hsLInstDeclBinders" hsLInstDeclBinders (dL->L _ (XInstDecl _)) = panic "hsLInstDeclBinders" hsLInstDeclBinders _ = panic "hsLInstDeclBinders: Impossible Match" -- due to #15884 ------------------- -- the SrcLoc returned are for the whole declarations, not just the names hsDataFamInstBinders :: DataFamInstDecl pass -> ([Located (IdP pass)], [LFieldOcc pass]) hsDataFamInstBinders (DataFamInstDecl { dfid_eqn = HsIB { hsib_body = FamEqn { feqn_rhs = defn }}}) = hsDataDefnBinders defn -- There can't be repeated symbols because only data instances have binders hsDataFamInstBinders (DataFamInstDecl { dfid_eqn = HsIB { hsib_body = XFamEqn _}}) = panic "hsDataFamInstBinders" hsDataFamInstBinders (DataFamInstDecl (XHsImplicitBndrs _)) = panic "hsDataFamInstBinders" ------------------- -- the SrcLoc returned are for the whole declarations, not just the names hsDataDefnBinders :: HsDataDefn pass -> ([Located (IdP pass)], [LFieldOcc pass]) hsDataDefnBinders (HsDataDefn { dd_cons = cons }) = hsConDeclsBinders cons -- See Note [Binders in family instances] hsDataDefnBinders (XHsDataDefn _) = panic "hsDataDefnBinders" ------------------- type Seen pass = [LFieldOcc pass] -> [LFieldOcc pass] -- Filters out ones that have already been seen hsConDeclsBinders :: [LConDecl pass] -> ([Located (IdP pass)], [LFieldOcc pass]) -- See hsLTyClDeclBinders for what this does -- The function is boringly complicated because of the records -- And since we only have equality, we have to be a little careful hsConDeclsBinders cons = go id cons where go :: Seen pass -> [LConDecl pass] -> ([Located (IdP pass)], [LFieldOcc pass]) go _ [] = ([], []) go remSeen (r:rs) -- Don't re-mangle the location of field names, because we don't -- have a record of the full location of the field declaration anyway = let loc = getLoc r in case unLoc r of -- remove only the first occurrence of any seen field in order to -- avoid circumventing detection of duplicate fields (#9156) ConDeclGADT { con_names = names, con_args = args } -> (map (cL loc . unLoc) names ++ ns, flds ++ fs) where (remSeen', flds) = get_flds remSeen args (ns, fs) = go remSeen' rs ConDeclH98 { con_name = name, con_args = args } -> ([cL loc (unLoc name)] ++ ns, flds ++ fs) where (remSeen', flds) = get_flds remSeen args (ns, fs) = go remSeen' rs XConDecl _ -> panic "hsConDeclsBinders" get_flds :: Seen pass -> HsConDeclDetails pass -> (Seen pass, [LFieldOcc pass]) get_flds remSeen (RecCon flds) = (remSeen', fld_names) where fld_names = remSeen (concatMap (cd_fld_names . unLoc) (unLoc flds)) remSeen' = foldr (.) remSeen [deleteBy ((==) `on` unLoc . rdrNameFieldOcc . unLoc) v | v <- fld_names] get_flds remSeen _ = (remSeen, []) {- Note [SrcSpan for binders] ~~~~~~~~~~~~~~~~~~~~~~~~~~ When extracting the (Located RdrNme) for a binder, at least for the main name (the TyCon of a type declaration etc), we want to give it the @SrcSpan@ of the whole /declaration/, not just the name itself (which is how it appears in the syntax tree). This SrcSpan (for the entire declaration) is used as the SrcSpan for the Name that is finally produced, and hence for error messages. (See Trac #8607.) Note [Binders in family instances] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In a type or data family instance declaration, the type constructor is an *occurrence* not a binding site type instance T Int = Int -> Int -- No binders data instance S Bool = S1 | S2 -- Binders are S1,S2 ************************************************************************ * * Collecting binders the user did not write * * ************************************************************************ The job of this family of functions is to run through binding sites and find the set of all Names that were defined "implicitly", without being explicitly written by the user. The main purpose is to find names introduced by record wildcards so that we can avoid warning the user when they don't use those names (#4404) -} lStmtsImplicits :: [LStmtLR GhcRn (GhcPass idR) (Located (body (GhcPass idR)))] -> NameSet lStmtsImplicits = hs_lstmts where hs_lstmts :: [LStmtLR GhcRn (GhcPass idR) (Located (body (GhcPass idR)))] -> NameSet hs_lstmts = foldr (\stmt rest -> unionNameSet (hs_stmt (unLoc stmt)) rest) emptyNameSet hs_stmt :: StmtLR GhcRn (GhcPass idR) (Located (body (GhcPass idR))) -> NameSet hs_stmt (BindStmt _ pat _ _ _) = lPatImplicits pat hs_stmt (ApplicativeStmt _ args _) = unionNameSets (map do_arg args) where do_arg (_, ApplicativeArgOne _ pat _ _) = lPatImplicits pat do_arg (_, ApplicativeArgMany _ stmts _ _) = hs_lstmts stmts do_arg (_, XApplicativeArg _) = panic "lStmtsImplicits" hs_stmt (LetStmt _ binds) = hs_local_binds (unLoc binds) hs_stmt (BodyStmt {}) = emptyNameSet hs_stmt (LastStmt {}) = emptyNameSet hs_stmt (ParStmt _ xs _ _) = hs_lstmts [s | ParStmtBlock _ ss _ _ <- xs , s <- ss] hs_stmt (TransStmt { trS_stmts = stmts }) = hs_lstmts stmts hs_stmt (RecStmt { recS_stmts = ss }) = hs_lstmts ss hs_stmt (XStmtLR {}) = panic "lStmtsImplicits" hs_local_binds (HsValBinds _ val_binds) = hsValBindsImplicits val_binds hs_local_binds (HsIPBinds {}) = emptyNameSet hs_local_binds (EmptyLocalBinds _) = emptyNameSet hs_local_binds (XHsLocalBindsLR _) = emptyNameSet hsValBindsImplicits :: HsValBindsLR GhcRn (GhcPass idR) -> NameSet hsValBindsImplicits (XValBindsLR (NValBinds binds _)) = foldr (unionNameSet . lhsBindsImplicits . snd) emptyNameSet binds hsValBindsImplicits (ValBinds _ binds _) = lhsBindsImplicits binds lhsBindsImplicits :: LHsBindsLR GhcRn idR -> NameSet lhsBindsImplicits = foldBag unionNameSet (lhs_bind . unLoc) emptyNameSet where lhs_bind (PatBind { pat_lhs = lpat }) = lPatImplicits lpat lhs_bind _ = emptyNameSet lPatImplicits :: LPat GhcRn -> NameSet lPatImplicits = hs_lpat where hs_lpat lpat = hs_pat (unLoc lpat) hs_lpats = foldr (\pat rest -> hs_lpat pat `unionNameSet` rest) emptyNameSet hs_pat (LazyPat _ pat) = hs_lpat pat hs_pat (BangPat _ pat) = hs_lpat pat hs_pat (AsPat _ _ pat) = hs_lpat pat hs_pat (ViewPat _ _ pat) = hs_lpat pat hs_pat (ParPat _ pat) = hs_lpat pat hs_pat (ListPat _ pats) = hs_lpats pats hs_pat (TuplePat _ pats _) = hs_lpats pats hs_pat (SigPat _ pat _) = hs_lpat pat hs_pat (CoPat _ _ pat _) = hs_pat pat hs_pat (ConPatIn _ ps) = details ps hs_pat (ConPatOut {pat_args=ps}) = details ps hs_pat _ = emptyNameSet details (PrefixCon ps) = hs_lpats ps details (RecCon fs) = hs_lpats explicit `unionNameSet` mkNameSet (collectPatsBinders implicit) where (explicit, implicit) = partitionEithers [if pat_explicit then Left pat else Right pat | (i, fld) <- [0..] `zip` rec_flds fs , let pat = hsRecFieldArg (unLoc fld) pat_explicit = maybe True (i<) (rec_dotdot fs)] details (InfixCon p1 p2) = hs_lpat p1 `unionNameSet` hs_lpat p2