import SrcLoc ( Located(..), unLoc, noLoc )
import DynFlags ( DynFlag(..) )
import Maybes ( seqMaybe )
-import Maybe ( isNothing, catMaybes )
+import Maybe ( isNothing, isJust )
import Monad ( liftM )
import BasicTypes ( Boxity(..) )
\end{code}
bindTyVarsRn cls_doc tyvars ( \ tyvars' ->
rnContext cls_doc context `thenM` \ context' ->
rnFds cls_doc fds `thenM` \ fds' ->
- rnATs tyvars' ats `thenM` \ (ats', ats_fvs) ->
+ rnATs ats `thenM` \ (ats', ats_fvs) ->
renameSigs okClsDclSig sigs `thenM` \ sigs' ->
returnM (tyvars', context', fds', (ats', ats_fvs), sigs')
) `thenM` \ (tyvars', context', fds', (ats', ats_fvs), sigs') ->
%*********************************************************
\begin{code}
--- Although, we are processing type patterns here, all type variables should
+-- Although, we are processing type patterns here, all type variables will
-- already be in scope (they are the same as in the 'tcdTyVars' field of the
-- type declaration to which these patterns belong)
--
rnHsTyVars doc tvs = mappM (rnHsTyvar doc) tvs
rnHsTyvar doc tyvar = lookupOccRn tyvar
--- Rename associated data type declarations
+-- Rename kind signatures (signatures of indexed data types/newtypes and
+-- signatures of type functions)
--
-rnATs :: [LHsTyVarBndr Name] -> [LTyClDecl RdrName]
- -> RnM ([LTyClDecl Name], FreeVars)
-rnATs classLTyVars ats
- = mapFvRn (wrapLocFstM rn_at) ats
- where
- -- The parser won't accept anything, but a data declarations
- rn_at (tydecl@TyData {tcdCtxt = L ctxtL ctxt, tcdLName = tycon,
- tcdTyPats = Just typats, tcdCons = condecls,
- tcdDerivs = derivs}) =
- do { checkM (null ctxt ) $ addErr atNoCtxt -- no context
- ; checkM (null condecls) $ addErr atNoCons -- no constructors
- -- check and collect type parameters
- ; let (idxParms, excessParms) = splitAt (length classLTyVars) typats
- ; zipWithM_ cmpTyVar idxParms classLTyVars
- ; excessTyVars <- liftM catMaybes $ mappM chkTyVar excessParms
- -- bind excess parameters
- ; bindTyVarsRn data_doc excessTyVars $ \ excessTyVars' -> do {
+-- * This function is parametrised by the routine handling the index
+-- variables. On the toplevel, these are defining occurences, whereas they
+-- are usage occurences for associated types.
+--
+rnTySig :: TyClDecl RdrName
+ -> (SDoc -> [LHsTyVarBndr RdrName] ->
+ ([LHsTyVarBndr Name] -> RnM (TyClDecl Name, FreeVars)) ->
+ RnM (TyClDecl Name, FreeVars))
+ -> RnM (TyClDecl Name, FreeVars)
+
+rnTySig (tydecl@TyData {tcdCtxt = context, tcdLName = tycon,
+ tcdTyVars = tyvars, tcdTyPats = mb_typats,
+ tcdCons = condecls, tcdKindSig = sig,
+ tcdDerivs = derivs})
+ bindIdxVars =
+ ASSERT( null condecls ) -- won't have constructors
+ ASSERT( isNothing mb_typats ) -- won't have type patterns
+ ASSERT( isNothing derivs ) -- won't have deriving
+ ASSERT( isJust sig ) -- will have kind signature
+ do { checkM (not . null $ tyvars) $ addErr needOneIdx -- #indexes >= 1
+ ; bindIdxVars (ksig_doc tycon) tyvars $ \tyvars' -> do {
; tycon' <- lookupLocatedTopBndrRn tycon
- ; (derivs', deriv_fvs) <- rn_derivs derivs
- ; returnM (TyData {tcdND = tcdND tydecl, tcdCtxt = L ctxtL [],
- tcdLName = tycon',
- tcdTyVars = classLTyVars ++ excessTyVars',
- tcdTyPats = Nothing, tcdKindSig = Nothing,
- tcdCons = [], tcdDerivs = derivs'},
- delFVs (map hsLTyVarName (classLTyVars ++ excessTyVars')) $
- deriv_fvs) } }
+ ; context' <- rnContext (ksig_doc tycon) context
+ ; returnM (TyData {tcdND = tcdND tydecl, tcdCtxt = context',
+ tcdLName = tycon', tcdTyVars = tyvars',
+ tcdTyPats = Nothing, tcdKindSig = sig,
+ tcdCons = [], tcdDerivs = Nothing},
+ delFVs (map hsLTyVarName tyvars') $
+ extractHsCtxtTyNames context') } }
where
- -- Check that the name space is correct!
- cmpTyVar (L l ty@(HsTyVar tv)) classTV = -- just a type variable
- checkM (rdrNameOcc tv == nameOccName classTVName) $
- mustMatchErr l ty classTVName
- where
- classTVName = hsLTyVarName classTV
- cmpTyVar (L l ty@(HsKindSig (L _ (HsTyVar tv)) k)) _ | isRdrTyVar tv =
- noKindSigErr l tv -- additional kind sig not allowed at class parms
- cmpTyVar (L l otherTy) _ =
- tyVarExpectedErr l -- parameter must be a type variable
-
- -- Check that the name space is correct!
- chkTyVar (L l (HsKindSig (L _ (HsTyVar tv)) k))
- | isRdrTyVar tv = return $ Just (L l (KindedTyVar tv k))
- chkTyVar (L l (HsTyVar tv))
- | isRdrTyVar tv = return $ Just (L l (UserTyVar tv))
- chkTyVar (L l otherTy) = tyVarExpectedErr l >> return Nothing
- -- drop parameter; we stop after renaming anyways
-
- rn_derivs Nothing = returnM (Nothing, emptyFVs)
- rn_derivs (Just ds) = do
- ds' <- rnLHsTypes data_doc ds
- returnM (Just ds', extractHsTyNames_s ds')
-
- atNoCtxt = text "Associated data type declarations cannot have a context"
- atNoCons = text "Associated data type declarations cannot have any constructors"
- data_doc = text "In the data type declaration for" <+> quotes (ppr tycon)
-
-noKindSigErr l ty =
- addErrAt l $
- sep [ptext SLIT("No kind signature allowed at copies of class parameters:"),
- nest 2 $ ppr ty]
-
-mustMatchErr l ty classTV =
- addErrAt l $
- sep [ptext SLIT("Type variable"), quotes (ppr ty),
- ptext SLIT("must match corresponding class parameter"),
- quotes (ppr classTV)]
-
-tyVarExpectedErr l =
- addErrAt l (ptext SLIT("Type found where type variable expected"))
+
+rnTySig (tydecl@TyFunction {tcdLName = tycon, tcdTyVars = tyvars,
+ tcdKind = sig})
+ bindIdxVars =
+ do { checkM (not . null $ tyvars) $ addErr needOneIdx -- #indexes >= 1
+ ; bindIdxVars (ksig_doc tycon) tyvars $ \tyvars' -> do {
+ ; tycon' <- lookupLocatedTopBndrRn tycon
+ ; returnM (TyFunction {tcdLName = tycon', tcdTyVars = tyvars',
+ tcdIso = tcdIso tydecl, tcdKind = sig},
+ emptyFVs) } }
+
+ksig_doc tycon = text "In the kind signature for" <+> quotes (ppr tycon)
+needOneIdx = text "Kind signature requires at least one type index"
+
+-- Rename associated type declarations (in classes)
+--
+-- * This can be data declarations, type function signatures, and (default)
+-- type function equations.
+--
+rnATs :: [LTyClDecl RdrName] -> RnM ([LTyClDecl Name], FreeVars)
+rnATs ats = mapFvRn (wrapLocFstM rn_at) ats
+ where
+ rn_at (tydecl@TyData {}) = rnTySig tydecl lookupIdxVars
+ rn_at (tydecl@TyFunction {}) = rnTySig tydecl lookupIdxVars
+ rn_at (tydelc@TySynonym {}) = panic "!!!TODO: case not impl yet"
+ rn_at _ = panic "RnSource.rnATs: invalid TyClDecl"
+
+ lookupIdxVars _ tyvars cont = mappM lookupIdxVar tyvars >>= cont
+ --
+ -- Type index variables must be class parameters, which are the only
+ -- type variables in scope at this point.
+ lookupIdxVar (L l tyvar) =
+ do
+ name' <- lookupOccRn (hsTyVarName tyvar)
+ return $ L l (replaceTyVarName tyvar name')
\end{code}
projects / ghc-hetmet.git / commitdiff