zonkTcKindToKind, zonkTcKind, zonkTopTyVar,
readKindVar, writeKindVar
-
) where
#include "HsVersions.h"
-- Make a new meta tyvar out of thin air
newMetaTyVar box_info kind
= do { uniq <- newUnique
- ; ref <- newMutVar Flexi ;
+ ; ref <- newMutVar Flexi
; let name = mkSysTvName uniq fs
fs = case box_info of
BoxTv -> FSLIT("t")
-- come from an existing TyVar
instMetaTyVar box_info tyvar
= do { uniq <- newUnique
- ; ref <- newMutVar Flexi ;
+ ; ref <- newMutVar Flexi
; let name = setNameUnique (tyVarName tyvar) uniq
kind = tyVarKind tyvar
; return (mkTcTyVar name kind (MetaTv box_info ref)) }
| otherwise
= ASSERT( isMetaTyVar tyvar )
- ASSERT2( k2 `isSubKind` k1, (ppr tyvar <+> ppr k1) $$ (ppr ty <+> ppr k2) )
+ -- TOM: It should also work for coercions
+ -- ASSERT2( k2 `isSubKind` k1, (ppr tyvar <+> ppr k1) $$ (ppr ty <+> ppr k2) )
do { ASSERTM2( do { details <- readMetaTyVar tyvar; return (isFlexi details) }, ppr tyvar )
; writeMutVar (metaTvRef tyvar) (Indirect ty) }
where
readFilledBox box_tv = ASSERT( isBoxyTyVar box_tv )
do { cts <- readMetaTyVar box_tv
; case cts of
- Flexi -> pprPanic "readFilledBox" (ppr box_tv)
+ Flexi -> pprPanic "readFilledBox" (ppr box_tv)
Indirect ty -> return ty }
tcInstBoxyTyVar :: TyVar -> TcM BoxyTyVar
MetaTv _ ref -> do { meta_details <- readMutVar ref
; case meta_details of
Indirect ty -> return (IndirectTv ty)
- Flexi -> return (DoneTv details) }
+ Flexi -> return (DoneTv details) }
where
details = tcTyVarDetails tyvar
other -> flexible_contexts || all tyvar_head tys
where
flexible_contexts = dopt Opt_FlexibleContexts dflags
- undecidable_ok = dopt Opt_AllowUndecidableInstances dflags
+ undecidable_ok = dopt Opt_UndecidableInstances dflags
-------------------------
tyvar_head ty -- Haskell 98 allows predicates of form
\begin{code}
checkValidInstance :: [TyVar] -> ThetaType -> Class -> [TcType] -> TcM ()
checkValidInstance tyvars theta clas inst_tys
- = do { undecidable_ok <- doptM Opt_AllowUndecidableInstances
+ = do { undecidable_ok <- doptM Opt_UndecidableInstances
; checkValidTheta InstThetaCtxt theta
; checkAmbiguity tyvars theta (tyVarsOfTypes inst_tys)