%
% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 19921998
%
This module converts Template Haskell syntax into HsSyn
\begin{code}
module Convert( convertToHsExpr, convertToPat, convertToHsDecls,
convertToHsType, convertToHsPred,
thRdrNameGuesses ) where
import HsSyn as Hs
import qualified Class
import RdrName
import qualified Name
import Module
import RdrHsSyn
import qualified OccName
import OccName
import SrcLoc
import Type
import Coercion
import TysWiredIn
import BasicTypes as Hs
import ForeignCall
import Unique
import MonadUtils
import ErrUtils
import Bag
import Util
import FastString
import Outputable
import Control.Monad( unless )
import Language.Haskell.TH as TH hiding (sigP)
import Language.Haskell.TH.Syntax as TH
import GHC.Exts
convertToHsDecls :: SrcSpan -> [TH.Dec] -> Either Message [LHsDecl RdrName]
convertToHsDecls loc ds = initCvt loc (mapM cvt_dec ds)
where
cvt_dec d = wrapMsg "declaration" d (cvtDec d)
convertToHsExpr :: SrcSpan -> TH.Exp -> Either Message (LHsExpr RdrName)
convertToHsExpr loc e
= initCvt loc $ wrapMsg "expression" e $ cvtl e
convertToPat :: SrcSpan -> TH.Pat -> Either Message (LPat RdrName)
convertToPat loc p
= initCvt loc $ wrapMsg "pattern" p $ cvtPat p
convertToHsType :: SrcSpan -> TH.Type -> Either Message (LHsType RdrName)
convertToHsType loc t
= initCvt loc $ wrapMsg "type" t $ cvtType t
convertToHsPred :: SrcSpan -> TH.Pred -> Either Message (LHsPred RdrName)
convertToHsPred loc t
= initCvt loc $ wrapMsg "type" t $ cvtPred t
newtype CvtM a = CvtM { unCvtM :: SrcSpan -> Either Message a }
instance Monad CvtM where
return x = CvtM $ \_ -> Right x
(CvtM m) >>= k = CvtM $ \loc -> case m loc of
Left err -> Left err
Right v -> unCvtM (k v) loc
initCvt :: SrcSpan -> CvtM a -> Either Message a
initCvt loc (CvtM m) = m loc
force :: a -> CvtM ()
force a = a `seq` return ()
failWith :: Message -> CvtM a
failWith m = CvtM (\_ -> Left m)
returnL :: a -> CvtM (Located a)
returnL x = CvtM (\loc -> Right (L loc x))
wrapMsg :: (Show a, TH.Ppr a) => String -> a -> CvtM b -> CvtM b
wrapMsg what item (CvtM m)
= CvtM (\loc -> case m loc of
Left err -> Left (err $$ getPprStyle msg)
Right v -> Right v)
where
msg sty = hang (ptext (sLit "When splicing a TH") <+> text what <> colon)
2 (if debugStyle sty
then text (show item)
else text (pprint item))
wrapL :: CvtM a -> CvtM (Located a)
wrapL (CvtM m) = CvtM (\loc -> case m loc of
Left err -> Left err
Right v -> Right (L loc v))
cvtDec :: TH.Dec -> CvtM (LHsDecl RdrName)
cvtDec (TH.ValD pat body ds)
| TH.VarP s <- pat
= do { s' <- vNameL s
; cl' <- cvtClause (Clause [] body ds)
; returnL $ Hs.ValD $ mkFunBind s' [cl'] }
| otherwise
= do { pat' <- cvtPat pat
; body' <- cvtGuard body
; ds' <- cvtLocalDecs (ptext (sLit "a where clause")) ds
; returnL $ Hs.ValD $
PatBind { pat_lhs = pat', pat_rhs = GRHSs body' ds'
, pat_rhs_ty = void, bind_fvs = placeHolderNames } }
cvtDec (TH.FunD nm cls)
| null cls
= failWith (ptext (sLit "Function binding for")
<+> quotes (text (TH.pprint nm))
<+> ptext (sLit "has no equations"))
| otherwise
= do { nm' <- vNameL nm
; cls' <- mapM cvtClause cls
; returnL $ Hs.ValD $ mkFunBind nm' cls' }
cvtDec (TH.SigD nm typ)
= do { nm' <- vNameL nm
; ty' <- cvtType typ
; returnL $ Hs.SigD (TypeSig nm' ty') }
cvtDec (PragmaD prag)
= do { prag' <- cvtPragmaD prag
; returnL $ Hs.SigD prag' }
cvtDec (TySynD tc tvs rhs)
= do { (_, tc', tvs') <- cvt_tycl_hdr [] tc tvs
; rhs' <- cvtType rhs
; returnL $ TyClD (TySynonym tc' tvs' Nothing rhs') }
cvtDec (DataD ctxt tc tvs constrs derivs)
= do { (ctxt', tc', tvs') <- cvt_tycl_hdr ctxt tc tvs
; cons' <- mapM cvtConstr constrs
; derivs' <- cvtDerivs derivs
; returnL $ TyClD (TyData { tcdND = DataType, tcdLName = tc', tcdCtxt = ctxt'
, tcdTyVars = tvs', tcdTyPats = Nothing, tcdKindSig = Nothing
, tcdCons = cons', tcdDerivs = derivs' }) }
cvtDec (NewtypeD ctxt tc tvs constr derivs)
= do { (ctxt', tc', tvs') <- cvt_tycl_hdr ctxt tc tvs
; con' <- cvtConstr constr
; derivs' <- cvtDerivs derivs
; returnL $ TyClD (TyData { tcdND = NewType, tcdLName = tc', tcdCtxt = ctxt'
, tcdTyVars = tvs', tcdTyPats = Nothing, tcdKindSig = Nothing
, tcdCons = [con'], tcdDerivs = derivs'}) }
cvtDec (ClassD ctxt cl tvs fds decs)
= do { (cxt', tc', tvs') <- cvt_tycl_hdr ctxt cl tvs
; fds' <- mapM cvt_fundep fds
; (binds', sigs', ats') <- cvt_ci_decs (ptext (sLit "a class declaration")) decs
; returnL $
TyClD $ ClassDecl { tcdCtxt = cxt', tcdLName = tc', tcdTyVars = tvs'
, tcdFDs = fds', tcdSigs = sigs', tcdMeths = binds'
, tcdATs = ats', tcdDocs = [] }
}
cvtDec (InstanceD ctxt ty decs)
= do { (binds', sigs', ats') <- cvt_ci_decs (ptext (sLit "an instance declaration")) decs
; ctxt' <- cvtContext ctxt
; L loc pred' <- cvtPredTy ty
; let inst_ty' = L loc $ mkImplicitHsForAllTy ctxt' $ L loc $ HsPredTy pred'
; returnL $ InstD (InstDecl inst_ty' binds' sigs' ats') }
cvtDec (ForeignD ford)
= do { ford' <- cvtForD ford
; returnL $ ForD ford' }
cvtDec (FamilyD flav tc tvs kind)
= do { (_, tc', tvs') <- cvt_tycl_hdr [] tc tvs
; let kind' = fmap cvtKind kind
; returnL $ TyClD (TyFamily (cvtFamFlavour flav) tc' tvs' kind') }
where
cvtFamFlavour TypeFam = TypeFamily
cvtFamFlavour DataFam = DataFamily
cvtDec (DataInstD ctxt tc tys constrs derivs)
= do { (ctxt', tc', tvs', typats') <- cvt_tyinst_hdr ctxt tc tys
; cons' <- mapM cvtConstr constrs
; derivs' <- cvtDerivs derivs
; returnL $ TyClD (TyData { tcdND = DataType, tcdLName = tc', tcdCtxt = ctxt'
, tcdTyVars = tvs', tcdTyPats = typats', tcdKindSig = Nothing
, tcdCons = cons', tcdDerivs = derivs' }) }
cvtDec (NewtypeInstD ctxt tc tys constr derivs)
= do { (ctxt', tc', tvs', typats') <- cvt_tyinst_hdr ctxt tc tys
; con' <- cvtConstr constr
; derivs' <- cvtDerivs derivs
; returnL $ TyClD (TyData { tcdND = NewType, tcdLName = tc', tcdCtxt = ctxt'
, tcdTyVars = tvs', tcdTyPats = typats', tcdKindSig = Nothing
, tcdCons = [con'], tcdDerivs = derivs' })
}
cvtDec (TySynInstD tc tys rhs)
= do { (_, tc', tvs', tys') <- cvt_tyinst_hdr [] tc tys
; rhs' <- cvtType rhs
; returnL $ TyClD (TySynonym tc' tvs' tys' rhs') }
cvt_ci_decs :: Message -> [TH.Dec]
-> CvtM (LHsBinds RdrName,
[LSig RdrName],
[LTyClDecl RdrName])
cvt_ci_decs doc decs
= do { decs' <- mapM cvtDec decs
; let (ats', bind_sig_decs') = partitionWith is_tycl decs'
; let (sigs', prob_binds') = partitionWith is_sig bind_sig_decs'
; let (binds', bads) = partitionWith is_bind prob_binds'
; unless (null bads) (failWith (mkBadDecMsg doc bads))
; return (listToBag binds', sigs', ats') }
cvt_tycl_hdr :: TH.Cxt -> TH.Name -> [TH.TyVarBndr]
-> CvtM ( LHsContext RdrName
, Located RdrName
, [LHsTyVarBndr RdrName])
cvt_tycl_hdr cxt tc tvs
= do { cxt' <- cvtContext cxt
; tc' <- tconNameL tc
; tvs' <- cvtTvs tvs
; return (cxt', tc', tvs')
}
cvt_tyinst_hdr :: TH.Cxt -> TH.Name -> [TH.Type]
-> CvtM ( LHsContext RdrName
, Located RdrName
, [LHsTyVarBndr RdrName]
, Maybe [LHsType RdrName])
cvt_tyinst_hdr cxt tc tys
= do { cxt' <- cvtContext cxt
; tc' <- tconNameL tc
; tvs <- concatMapM collect tys
; tvs' <- cvtTvs tvs
; tys' <- mapM cvtType tys
; return (cxt', tc', tvs', Just tys')
}
where
collect (ForallT _ _ _)
= failWith $ text "Forall type not allowed as type parameter"
collect (VarT tv) = return [PlainTV tv]
collect (ConT _) = return []
collect (TupleT _) = return []
collect ArrowT = return []
collect ListT = return []
collect (AppT t1 t2)
= do { tvs1 <- collect t1
; tvs2 <- collect t2
; return $ tvs1 ++ tvs2
}
collect (SigT (VarT tv) ki) = return [KindedTV tv ki]
collect (SigT ty _) = collect ty
is_tycl :: LHsDecl RdrName -> Either (LTyClDecl RdrName) (LHsDecl RdrName)
is_tycl (L loc (Hs.TyClD tcd)) = Left (L loc tcd)
is_tycl decl = Right decl
is_sig :: LHsDecl RdrName -> Either (LSig RdrName) (LHsDecl RdrName)
is_sig (L loc (Hs.SigD sig)) = Left (L loc sig)
is_sig decl = Right decl
is_bind :: LHsDecl RdrName -> Either (LHsBind RdrName) (LHsDecl RdrName)
is_bind (L loc (Hs.ValD bind)) = Left (L loc bind)
is_bind decl = Right decl
mkBadDecMsg :: Message -> [LHsDecl RdrName] -> Message
mkBadDecMsg doc bads
= sep [ ptext (sLit "Illegal declaration(s) in") <+> doc <> colon
, nest 2 (vcat (map Outputable.ppr bads)) ]
cvtConstr :: TH.Con -> CvtM (LConDecl RdrName)
cvtConstr (NormalC c strtys)
= do { c' <- cNameL c
; cxt' <- returnL []
; tys' <- mapM cvt_arg strtys
; returnL $ mkSimpleConDecl c' noExistentials cxt' (PrefixCon tys') }
cvtConstr (RecC c varstrtys)
= do { c' <- cNameL c
; cxt' <- returnL []
; args' <- mapM cvt_id_arg varstrtys
; returnL $ mkSimpleConDecl c' noExistentials cxt' (RecCon args') }
cvtConstr (InfixC st1 c st2)
= do { c' <- cNameL c
; cxt' <- returnL []
; st1' <- cvt_arg st1
; st2' <- cvt_arg st2
; returnL $ mkSimpleConDecl c' noExistentials cxt' (InfixCon st1' st2') }
cvtConstr (ForallC tvs ctxt con)
= do { tvs' <- cvtTvs tvs
; L loc ctxt' <- cvtContext ctxt
; L _ con' <- cvtConstr con
; returnL $ con' { con_qvars = tvs' ++ con_qvars con'
, con_cxt = L loc (ctxt' ++ (unLoc $ con_cxt con')) } }
cvt_arg :: (TH.Strict, TH.Type) -> CvtM (LHsType RdrName)
cvt_arg (IsStrict, ty) = do { ty' <- cvtType ty; returnL $ HsBangTy HsStrict ty' }
cvt_arg (NotStrict, ty) = cvtType ty
cvt_id_arg :: (TH.Name, TH.Strict, TH.Type) -> CvtM (ConDeclField RdrName)
cvt_id_arg (i, str, ty)
= do { i' <- vNameL i
; ty' <- cvt_arg (str,ty)
; return (ConDeclField { cd_fld_name = i', cd_fld_type = ty', cd_fld_doc = Nothing}) }
cvtDerivs :: [TH.Name] -> CvtM (Maybe [LHsType RdrName])
cvtDerivs [] = return Nothing
cvtDerivs cs = do { cs' <- mapM cvt_one cs
; return (Just cs') }
where
cvt_one c = do { c' <- tconName c
; returnL $ HsPredTy $ HsClassP c' [] }
cvt_fundep :: FunDep -> CvtM (Located (Class.FunDep RdrName))
cvt_fundep (FunDep xs ys) = do { xs' <- mapM tName xs; ys' <- mapM tName ys; returnL (xs', ys') }
noExistentials :: [LHsTyVarBndr RdrName]
noExistentials = []
cvtForD :: Foreign -> CvtM (ForeignDecl RdrName)
cvtForD (ImportF callconv safety from nm ty)
| Just impspec <- parseCImport (cvt_conv callconv) safety'
(mkFastString (TH.nameBase nm)) from
= do { nm' <- vNameL nm
; ty' <- cvtType ty
; return (ForeignImport nm' ty' impspec)
}
| otherwise
= failWith $ text (show from) <+> ptext (sLit "is not a valid ccall impent")
where
safety' = case safety of
Unsafe -> PlayRisky
Safe -> PlaySafe False
Threadsafe -> PlaySafe True
cvtForD (ExportF callconv as nm ty)
= do { nm' <- vNameL nm
; ty' <- cvtType ty
; let e = CExport (CExportStatic (mkFastString as) (cvt_conv callconv))
; return $ ForeignExport nm' ty' e }
cvt_conv :: TH.Callconv -> CCallConv
cvt_conv TH.CCall = CCallConv
cvt_conv TH.StdCall = StdCallConv
cvtPragmaD :: Pragma -> CvtM (Sig RdrName)
cvtPragmaD (InlineP nm ispec)
= do { nm' <- vNameL nm
; return $ InlineSig nm' (cvtInlineSpec (Just ispec)) }
cvtPragmaD (SpecialiseP nm ty opt_ispec)
= do { nm' <- vNameL nm
; ty' <- cvtType ty
; return $ SpecSig nm' ty' (cvtInlineSpec opt_ispec) }
cvtInlineSpec :: Maybe TH.InlineSpec -> Hs.InlinePragma
cvtInlineSpec Nothing
= defaultInlinePragma
cvtInlineSpec (Just (TH.InlineSpec inline conlike opt_activation))
= InlinePragma { inl_act = opt_activation', inl_rule = matchinfo
, inl_inline = inl_spec, inl_sat = Nothing }
where
matchinfo = cvtRuleMatchInfo conlike
opt_activation' = cvtActivation opt_activation
cvtRuleMatchInfo False = FunLike
cvtRuleMatchInfo True = ConLike
inl_spec | inline = Inline
| otherwise = NoInline
cvtActivation Nothing | inline = AlwaysActive
| otherwise = NeverActive
cvtActivation (Just (False, phase)) = ActiveBefore phase
cvtActivation (Just (True , phase)) = ActiveAfter phase
cvtLocalDecs :: Message -> [TH.Dec] -> CvtM (HsLocalBinds RdrName)
cvtLocalDecs doc ds
| null ds
= return EmptyLocalBinds
| otherwise
= do { ds' <- mapM cvtDec ds
; let (binds, prob_sigs) = partitionWith is_bind ds'
; let (sigs, bads) = partitionWith is_sig prob_sigs
; unless (null bads) (failWith (mkBadDecMsg doc bads))
; return (HsValBinds (ValBindsIn (listToBag binds) sigs)) }
cvtClause :: TH.Clause -> CvtM (Hs.LMatch RdrName)
cvtClause (Clause ps body wheres)
= do { ps' <- cvtPats ps
; g' <- cvtGuard body
; ds' <- cvtLocalDecs (ptext (sLit "a where clause")) wheres
; returnL $ Hs.Match ps' Nothing (GRHSs g' ds') }
cvtl :: TH.Exp -> CvtM (LHsExpr RdrName)
cvtl e = wrapL (cvt e)
where
cvt (VarE s) = do { s' <- vName s; return $ HsVar s' }
cvt (ConE s) = do { s' <- cName s; return $ HsVar s' }
cvt (LitE l)
| overloadedLit l = do { l' <- cvtOverLit l; return $ HsOverLit l' }
| otherwise = do { l' <- cvtLit l; return $ HsLit l' }
cvt (AppE x y) = do { x' <- cvtl x; y' <- cvtl y; return $ HsApp x' y' }
cvt (LamE ps e) = do { ps' <- cvtPats ps; e' <- cvtl e
; return $ HsLam (mkMatchGroup [mkSimpleMatch ps' e']) }
cvt (TupE [e]) = cvt e
cvt (TupE es) = do { es' <- mapM cvtl es; return $ ExplicitTuple (map Present es') Boxed }
cvt (CondE x y z) = do { x' <- cvtl x; y' <- cvtl y; z' <- cvtl z;
; return $ HsIf (Just noSyntaxExpr) x' y' z' }
cvt (LetE ds e) = do { ds' <- cvtLocalDecs (ptext (sLit "a let expression")) ds
; e' <- cvtl e; return $ HsLet ds' e' }
cvt (CaseE e ms)
| null ms = failWith (ptext (sLit "Case expression with no alternatives"))
| otherwise = do { e' <- cvtl e; ms' <- mapM cvtMatch ms
; return $ HsCase e' (mkMatchGroup ms') }
cvt (DoE ss) = cvtHsDo DoExpr ss
cvt (CompE ss) = cvtHsDo ListComp ss
cvt (ArithSeqE dd) = do { dd' <- cvtDD dd; return $ ArithSeq noPostTcExpr dd' }
cvt (ListE xs)
| Just s <- allCharLs xs = do { l' <- cvtLit (StringL s); return (HsLit l') }
| otherwise = do { xs' <- mapM cvtl xs; return $ ExplicitList void xs' }
cvt (InfixE (Just x) s (Just y)) = do { x' <- cvtl x; s' <- cvtl s; y' <- cvtl y
; e' <- returnL $ OpApp x' s' undefined y'
; return $ HsPar e' }
cvt (InfixE Nothing s (Just y)) = do { s' <- cvtl s; y' <- cvtl y
; sec <- returnL $ SectionR s' y'
; return $ HsPar sec }
cvt (InfixE (Just x) s Nothing ) = do { x' <- cvtl x; s' <- cvtl s
; sec <- returnL $ SectionL x' s'
; return $ HsPar sec }
cvt (InfixE Nothing s Nothing ) = cvt s
cvt (SigE e t) = do { e' <- cvtl e; t' <- cvtType t
; return $ ExprWithTySig e' t' }
cvt (RecConE c flds) = do { c' <- cNameL c
; flds' <- mapM cvtFld flds
; return $ RecordCon c' noPostTcExpr (HsRecFields flds' Nothing)}
cvt (RecUpdE e flds) = do { e' <- cvtl e
; flds' <- mapM cvtFld flds
; return $ RecordUpd e' (HsRecFields flds' Nothing) [] [] [] }
cvtFld :: (TH.Name, TH.Exp) -> CvtM (HsRecField RdrName (LHsExpr RdrName))
cvtFld (v,e)
= do { v' <- vNameL v; e' <- cvtl e
; return (HsRecField { hsRecFieldId = v', hsRecFieldArg = e', hsRecPun = False}) }
cvtDD :: Range -> CvtM (ArithSeqInfo RdrName)
cvtDD (FromR x) = do { x' <- cvtl x; return $ From x' }
cvtDD (FromThenR x y) = do { x' <- cvtl x; y' <- cvtl y; return $ FromThen x' y' }
cvtDD (FromToR x y) = do { x' <- cvtl x; y' <- cvtl y; return $ FromTo x' y' }
cvtDD (FromThenToR x y z) = do { x' <- cvtl x; y' <- cvtl y; z' <- cvtl z; return $ FromThenTo x' y' z' }
cvtHsDo :: HsStmtContext Name.Name -> [TH.Stmt] -> CvtM (HsExpr RdrName)
cvtHsDo do_or_lc stmts
| null stmts = failWith (ptext (sLit "Empty stmt list in do-block"))
| otherwise
= do { stmts' <- cvtStmts stmts
; body <- case last stmts' of
L _ (ExprStmt body _ _) -> return body
stmt' -> failWith (bad_last stmt')
; return $ HsDo do_or_lc (init stmts') body void }
where
bad_last stmt = vcat [ ptext (sLit "Illegal last statement of") <+> pprStmtContext do_or_lc <> colon
, nest 2 $ Outputable.ppr stmt
, ptext (sLit "(It should be an expression.)") ]
cvtStmts :: [TH.Stmt] -> CvtM [Hs.LStmt RdrName]
cvtStmts = mapM cvtStmt
cvtStmt :: TH.Stmt -> CvtM (Hs.LStmt RdrName)
cvtStmt (NoBindS e) = do { e' <- cvtl e; returnL $ mkExprStmt e' }
cvtStmt (TH.BindS p e) = do { p' <- cvtPat p; e' <- cvtl e; returnL $ mkBindStmt p' e' }
cvtStmt (TH.LetS ds) = do { ds' <- cvtLocalDecs (ptext (sLit "a let binding")) ds
; returnL $ LetStmt ds' }
cvtStmt (TH.ParS dss) = do { dss' <- mapM cvt_one dss; returnL $ ParStmt dss' }
where
cvt_one ds = do { ds' <- cvtStmts ds; return (ds', undefined) }
cvtMatch :: TH.Match -> CvtM (Hs.LMatch RdrName)
cvtMatch (TH.Match p body decs)
= do { p' <- cvtPat p
; g' <- cvtGuard body
; decs' <- cvtLocalDecs (ptext (sLit "a where clause")) decs
; returnL $ Hs.Match [p'] Nothing (GRHSs g' decs') }
cvtGuard :: TH.Body -> CvtM [LGRHS RdrName]
cvtGuard (GuardedB pairs) = mapM cvtpair pairs
cvtGuard (NormalB e) = do { e' <- cvtl e; g' <- returnL $ GRHS [] e'; return [g'] }
cvtpair :: (TH.Guard, TH.Exp) -> CvtM (LGRHS RdrName)
cvtpair (NormalG ge,rhs) = do { ge' <- cvtl ge; rhs' <- cvtl rhs
; g' <- returnL $ mkExprStmt ge'
; returnL $ GRHS [g'] rhs' }
cvtpair (PatG gs,rhs) = do { gs' <- cvtStmts gs; rhs' <- cvtl rhs
; returnL $ GRHS gs' rhs' }
cvtOverLit :: Lit -> CvtM (HsOverLit RdrName)
cvtOverLit (IntegerL i)
= do { force i; return $ mkHsIntegral i placeHolderType}
cvtOverLit (RationalL r)
= do { force r; return $ mkHsFractional r placeHolderType}
cvtOverLit (StringL s)
= do { let { s' = mkFastString s }
; force s'
; return $ mkHsIsString s' placeHolderType
}
cvtOverLit _ = panic "Convert.cvtOverLit: Unexpected overloaded literal"
allCharLs :: [TH.Exp] -> Maybe String
allCharLs xs
= case xs of
LitE (CharL c) : ys -> go [c] ys
_ -> Nothing
where
go cs [] = Just (reverse cs)
go cs (LitE (CharL c) : ys) = go (c:cs) ys
go _ _ = Nothing
cvtLit :: Lit -> CvtM HsLit
cvtLit (IntPrimL i) = do { force i; return $ HsIntPrim i }
cvtLit (WordPrimL w) = do { force w; return $ HsWordPrim w }
cvtLit (FloatPrimL f) = do { force f; return $ HsFloatPrim f }
cvtLit (DoublePrimL f) = do { force f; return $ HsDoublePrim f }
cvtLit (CharL c) = do { force c; return $ HsChar c }
cvtLit (StringL s) = do { let { s' = mkFastString s }
; force s'
; return $ HsString s' }
cvtLit (StringPrimL s) = do { let { s' = mkFastString s }
; force s'
; return $ HsStringPrim s' }
cvtLit _ = panic "Convert.cvtLit: Unexpected literal"
cvtPats :: [TH.Pat] -> CvtM [Hs.LPat RdrName]
cvtPats pats = mapM cvtPat pats
cvtPat :: TH.Pat -> CvtM (Hs.LPat RdrName)
cvtPat pat = wrapL (cvtp pat)
cvtp :: TH.Pat -> CvtM (Hs.Pat RdrName)
cvtp (TH.LitP l)
| overloadedLit l = do { l' <- cvtOverLit l
; return (mkNPat l' Nothing) }
| otherwise = do { l' <- cvtLit l; return $ Hs.LitPat l' }
cvtp (TH.VarP s) = do { s' <- vName s; return $ Hs.VarPat s' }
cvtp (TupP [p]) = cvtp p
cvtp (TupP ps) = do { ps' <- cvtPats ps; return $ TuplePat ps' Boxed void }
cvtp (ConP s ps) = do { s' <- cNameL s; ps' <- cvtPats ps; return $ ConPatIn s' (PrefixCon ps') }
cvtp (InfixP p1 s p2) = do { s' <- cNameL s; p1' <- cvtPat p1; p2' <- cvtPat p2
; return $ ConPatIn s' (InfixCon p1' p2') }
cvtp (TildeP p) = do { p' <- cvtPat p; return $ LazyPat p' }
cvtp (BangP p) = do { p' <- cvtPat p; return $ BangPat p' }
cvtp (TH.AsP s p) = do { s' <- vNameL s; p' <- cvtPat p; return $ AsPat s' p' }
cvtp TH.WildP = return $ WildPat void
cvtp (RecP c fs) = do { c' <- cNameL c; fs' <- mapM cvtPatFld fs
; return $ ConPatIn c' $ Hs.RecCon (HsRecFields fs' Nothing) }
cvtp (ListP ps) = do { ps' <- cvtPats ps; return $ ListPat ps' void }
cvtp (SigP p t) = do { p' <- cvtPat p; t' <- cvtType t; return $ SigPatIn p' t' }
cvtp (ViewP e p) = do { e' <- cvtl e; p' <- cvtPat p; return $ ViewPat e' p' void }
cvtPatFld :: (TH.Name, TH.Pat) -> CvtM (HsRecField RdrName (LPat RdrName))
cvtPatFld (s,p)
= do { s' <- vNameL s; p' <- cvtPat p
; return (HsRecField { hsRecFieldId = s', hsRecFieldArg = p', hsRecPun = False}) }
cvtTvs :: [TH.TyVarBndr] -> CvtM [LHsTyVarBndr RdrName]
cvtTvs tvs = mapM cvt_tv tvs
cvt_tv :: TH.TyVarBndr -> CvtM (LHsTyVarBndr RdrName)
cvt_tv (TH.PlainTV nm)
= do { nm' <- tName nm
; returnL $ UserTyVar nm' placeHolderKind
}
cvt_tv (TH.KindedTV nm ki)
= do { nm' <- tName nm
; returnL $ KindedTyVar nm' (cvtKind ki)
}
cvtContext :: TH.Cxt -> CvtM (LHsContext RdrName)
cvtContext tys = do { preds' <- mapM cvtPred tys; returnL preds' }
cvtPred :: TH.Pred -> CvtM (LHsPred RdrName)
cvtPred (TH.ClassP cla tys)
= do { cla' <- if isVarName cla then tName cla else tconName cla
; tys' <- mapM cvtType tys
; returnL $ HsClassP cla' tys'
}
cvtPred (TH.EqualP ty1 ty2)
= do { ty1' <- cvtType ty1
; ty2' <- cvtType ty2
; returnL $ HsEqualP ty1' ty2'
}
cvtPredTy :: TH.Type -> CvtM (LHsPred RdrName)
cvtPredTy ty
= do { (head, tys') <- split_ty_app ty
; case head of
ConT tc -> do { tc' <- tconName tc; returnL $ HsClassP tc' tys' }
VarT tv -> do { tv' <- tName tv; returnL $ HsClassP tv' tys' }
_ -> failWith (ptext (sLit "Malformed predicate") <+>
text (TH.pprint ty)) }
cvtType :: TH.Type -> CvtM (LHsType RdrName)
cvtType ty
= do { (head_ty, tys') <- split_ty_app ty
; case head_ty of
TupleT n
| length tys' == n
-> if n==1 then return (head tys')
else returnL (HsTupleTy Boxed tys')
| n == 1
-> failWith (ptext (sLit "Illegal 1-tuple type constructor"))
| otherwise
-> mk_apps (HsTyVar (getRdrName (tupleTyCon Boxed n))) tys'
ArrowT
| [x',y'] <- tys' -> returnL (HsFunTy x' y')
| otherwise -> mk_apps (HsTyVar (getRdrName funTyCon)) tys'
ListT
| [x'] <- tys' -> returnL (HsListTy x')
| otherwise -> mk_apps (HsTyVar (getRdrName listTyCon)) tys'
VarT nm -> do { nm' <- tName nm; mk_apps (HsTyVar nm') tys' }
ConT nm -> do { nm' <- tconName nm; mk_apps (HsTyVar nm') tys' }
ForallT tvs cxt ty
| null tys'
-> do { tvs' <- cvtTvs tvs
; cxt' <- cvtContext cxt
; ty' <- cvtType ty
; returnL $ mkExplicitHsForAllTy tvs' cxt' ty'
}
SigT ty ki
-> do { ty' <- cvtType ty
; mk_apps (HsKindSig ty' (cvtKind ki)) tys'
}
_ -> failWith (ptext (sLit "Malformed type") <+> text (show ty))
}
where
mk_apps head_ty [] = returnL head_ty
mk_apps head_ty (ty:tys) = do { head_ty' <- returnL head_ty
; mk_apps (HsAppTy head_ty' ty) tys }
split_ty_app :: TH.Type -> CvtM (TH.Type, [LHsType RdrName])
split_ty_app ty = go ty []
where
go (AppT f a) as' = do { a' <- cvtType a; go f (a':as') }
go f as = return (f,as)
cvtKind :: TH.Kind -> Type.Kind
cvtKind StarK = liftedTypeKind
cvtKind (ArrowK k1 k2) = mkArrowKind (cvtKind k1) (cvtKind k2)
overloadedLit :: Lit -> Bool
overloadedLit (IntegerL _) = True
overloadedLit (RationalL _) = True
overloadedLit _ = False
void :: Type.Type
void = placeHolderType
vNameL, cNameL, tconNameL :: TH.Name -> CvtM (Located RdrName)
vName, cName, tName, tconName :: TH.Name -> CvtM RdrName
vNameL n = wrapL (vName n)
vName n = cvtName OccName.varName n
cNameL n = wrapL (cName n)
cName n = cvtName OccName.dataName n
tName n = cvtName OccName.tvName n
tconNameL n = wrapL (tconName n)
tconName n = cvtName OccName.tcClsName n
cvtName :: OccName.NameSpace -> TH.Name -> CvtM RdrName
cvtName ctxt_ns (TH.Name occ flavour)
| not (okOcc ctxt_ns occ_str) = failWith (badOcc ctxt_ns occ_str)
| otherwise = force rdr_name >> return rdr_name
where
occ_str = TH.occString occ
rdr_name = thRdrName ctxt_ns occ_str flavour
okOcc :: OccName.NameSpace -> String -> Bool
okOcc _ [] = False
okOcc ns str@(c:_)
| OccName.isVarNameSpace ns = startsVarId c || startsVarSym c
| otherwise = startsConId c || startsConSym c || str == "[]"
isVarName :: TH.Name -> Bool
isVarName (TH.Name occ _)
= case TH.occString occ of
"" -> False
(c:_) -> startsVarId c || startsVarSym c
badOcc :: OccName.NameSpace -> String -> SDoc
badOcc ctxt_ns occ
= ptext (sLit "Illegal") <+> pprNameSpace ctxt_ns
<+> ptext (sLit "name:") <+> quotes (text occ)
thRdrName :: OccName.NameSpace -> String -> TH.NameFlavour -> RdrName
thRdrName _ occ (TH.NameG th_ns pkg mod) = thOrigRdrName occ th_ns pkg mod
thRdrName ctxt_ns occ (TH.NameL uniq) = nameRdrName $! (((Name.mkInternalName $! (mk_uniq uniq)) $! (mk_occ ctxt_ns occ)) noSrcSpan)
thRdrName ctxt_ns occ (TH.NameQ mod) = (mkRdrQual $! (mk_mod mod)) $! (mk_occ ctxt_ns occ)
thRdrName ctxt_ns occ (TH.NameU uniq) = mkRdrUnqual $! (mk_uniq_occ ctxt_ns occ uniq)
thRdrName ctxt_ns occ TH.NameS
| Just name <- isBuiltInOcc ctxt_ns occ = nameRdrName $! name
| otherwise = mkRdrUnqual $! (mk_occ ctxt_ns occ)
thOrigRdrName :: String -> TH.NameSpace -> PkgName -> ModName -> RdrName
thOrigRdrName occ th_ns pkg mod = (mkOrig $! (mkModule (mk_pkg pkg) (mk_mod mod))) $! (mk_occ (mk_ghc_ns th_ns) occ)
thRdrNameGuesses :: TH.Name -> [RdrName]
thRdrNameGuesses (TH.Name occ flavour)
| TH.NameG th_ns pkg mod <- flavour = [thOrigRdrName occ_str th_ns pkg mod]
| otherwise = [ thRdrName gns occ_str flavour
| gns <- guessed_nss]
where
guessed_nss | isLexCon (mkFastString occ_str) = [OccName.tcName, OccName.dataName]
| otherwise = [OccName.varName, OccName.tvName]
occ_str = TH.occString occ
isBuiltInOcc :: OccName.NameSpace -> String -> Maybe Name.Name
isBuiltInOcc ctxt_ns occ
= case occ of
":" -> Just (Name.getName consDataCon)
"[]" -> Just (Name.getName nilDataCon)
"()" -> Just (tup_name 0)
'(' : ',' : rest -> go_tuple 2 rest
_ -> Nothing
where
go_tuple n ")" = Just (tup_name n)
go_tuple n (',' : rest) = go_tuple (n+1) rest
go_tuple _ _ = Nothing
tup_name n
| OccName.isTcClsNameSpace ctxt_ns = Name.getName (tupleTyCon Boxed n)
| otherwise = Name.getName (tupleCon Boxed n)
mk_uniq_occ :: OccName.NameSpace -> String -> Int# -> OccName.OccName
mk_uniq_occ ns occ uniq
= OccName.mkOccName ns (occ ++ '[' : shows (mk_uniq uniq) "]")
mk_occ :: OccName.NameSpace -> String -> OccName.OccName
mk_occ ns occ = OccName.mkOccNameFS ns (mkFastString occ)
mk_ghc_ns :: TH.NameSpace -> OccName.NameSpace
mk_ghc_ns TH.DataName = OccName.dataName
mk_ghc_ns TH.TcClsName = OccName.tcClsName
mk_ghc_ns TH.VarName = OccName.varName
mk_mod :: TH.ModName -> ModuleName
mk_mod mod = mkModuleName (TH.modString mod)
mk_pkg :: TH.PkgName -> PackageId
mk_pkg pkg = stringToPackageId (TH.pkgString pkg)
mk_uniq :: Int# -> Unique
mk_uniq u = mkUniqueGrimily (I# u)
\end{code}
Note [Unique OccNames from Template Haskell]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The idea here is to make a name that
a) the user could not possibly write (it has a "["
and letters or digits from the unique)
b) cannot clash with another NameU
Previously I generated an Exact RdrName with mkInternalName. This
works fine for local binders, but does not work at all for toplevel
binders, which must have External Names, since they are rapidly baked
into data constructors and the like. Baling out and generating an
unqualified RdrName here is the simple solution
See also Note [Suppressing uniques in OccNames] in OccName, which
suppresses the unique when opt_SuppressUniques is on.