import CmdLineOpts ( DynFlags, DynFlag(..), dopt )
import HsSyn ( TyClDecl(..),
ConDecl(..), Sig(..), HsPred(..),
- tyClDeclName, hsTyVarNames,
+ tyClDeclName, hsTyVarNames, tyClDeclTyVars,
isIfaceSigDecl, isClassDecl, isSynDecl, isClassOpSig
)
import RnHsSyn ( RenamedTyClDecl, tyClDeclFVs )
import TcMonad
import TcEnv ( TcEnv, RecTcEnv, TcTyThing(..), TyThing(..), TyThingDetails(..),
tcExtendKindEnv, tcLookup, tcExtendGlobalEnv, tcExtendGlobalValEnv )
-import TcTyDecls ( tcTyDecl1, kcConDetails, mkNewTyConRep )
+import TcTyDecls ( tcTyDecl1, kcConDetails )
import TcClassDcl ( tcClassDecl1 )
-import TcMonoType ( kcHsTyVars, kcHsType, kcHsLiftedSigType, kcHsContext, mkTyClTyVars )
-import TcType ( TcKind, newKindVar, zonkKindEnv )
-
-import TcUnify ( unifyKind )
import TcInstDcls ( tcAddDeclCtxt )
-import Type ( Kind, mkArrowKind, zipFunTys )
+import TcMonoType ( kcHsTyVars, kcHsType, kcHsLiftedSigType, kcHsContext, mkTyClTyVars )
+import TcMType ( unifyKind, newKindVar, zonkKindEnv )
+import TcType ( Type, Kind, mkArrowKind, liftedTypeKind, zipFunTys )
import Variance ( calcTyConArgVrcs )
import Class ( Class, mkClass, classTyCon )
-import TyCon ( TyCon, tyConKind, ArgVrcs, AlgTyConFlavour(..),
- mkSynTyCon, mkAlgTyCon, mkClassTyCon )
-import DataCon ( isNullaryDataCon )
+import TyCon ( TyCon, ArgVrcs, AlgTyConFlavour(..),
+ tyConKind, tyConDataCons,
+ mkSynTyCon, mkAlgTyCon, mkClassTyCon, mkForeignTyCon,
+ isRecursiveTyCon )
+import DataCon ( dataConOrigArgTys )
import Var ( varName )
import FiniteMap
import Digraph ( stronglyConnComp, SCC(..) )
import Name ( Name, getSrcLoc, isTyVarName )
-import NameEnv ( NameEnv, mkNameEnv, lookupNameEnv_NF )
+import NameEnv
import NameSet
import Outputable
import Maybes ( mapMaybe )
zonkKindEnv initial_kinds `thenNF_Tc` \ final_kinds ->
-- Tie the knot
+ traceTc (text "starting" <+> ppr final_kinds) `thenTc_`
fixTc ( \ ~(rec_details_list, _, _) ->
-- Step 4
let
tcSetEnv env $
+ traceTc (text "ready for pass 2" <+> ppr (isRec is_rec)) `thenTc_`
+
-- Step 6
-- For a recursive group, check all the types again,
-- this time with the wimp flag off
returnTc ()
) `thenTc_`
+ traceTc (text "done") `thenTc_`
+
-- Step 7
-- Extend the environment with the final TyCons/Classes
-- and their implicit Ids
\begin{code}
getInitialKind :: RenamedTyClDecl -> NF_TcM (Name, TcKind)
getInitialKind decl
- = kcHsTyVars (tcdTyVars decl) `thenNF_Tc` \ arg_kinds ->
- newKindVar `thenNF_Tc` \ result_kind ->
+ = kcHsTyVars (tyClDeclTyVars decl) `thenNF_Tc` \ arg_kinds ->
+ newKindVar `thenNF_Tc` \ result_kind ->
returnNF_Tc (tcdName decl, mk_kind arg_kinds result_kind)
mk_kind tvs_w_kinds res_kind = foldr (mkArrowKind . snd) res_kind tvs_w_kinds
kcHsType rhs `thenTc` \ rhs_kind ->
unifyKind result_kind rhs_kind
+kcTyClDecl (ForeignType {}) = returnTc ()
+
kcTyClDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = context, tcdCons = con_decls})
= kcTyClDeclBody decl $ \ result_kind ->
kcHsContext context `thenTc_`
AThing kind -> kind
-- For some odd reason, a class doesn't include its kind
- (tyvars_w_kinds, result_kind) = zipFunTys (hsTyVarNames (tcdTyVars decl)) kind
+ (tyvars_w_kinds, result_kind) = zipFunTys (hsTyVarNames (tyClDeclTyVars decl)) kind
in
tcExtendKindEnv tyvars_w_kinds (thing_inside result_kind)
\end{code}
tyvars = mkTyClTyVars tycon_kind tyvar_names
argvrcs = lookupWithDefaultFM rec_vrcs bogusVrcs tycon
+ -- Watch out! mkTyConApp asks whether the tycon is a NewType,
+ -- so flavour has to be able to answer this question without consulting rec_details
flavour = case data_or_new of
- NewType -> NewTyCon (mkNewTyConRep tycon)
- DataType | all isNullaryDataCon data_cons -> EnumTyCon
- | otherwise -> DataTyCon
+ NewType -> NewTyCon (mkNewTyConRep tycon)
+ DataType | all (null . dataConOrigArgTys) data_cons -> EnumTyCon
+ | otherwise -> DataTyCon
+ -- NB (null . dataConOrigArgTys). It used to say isNullaryDataCon
+ -- but that looks at the *representation* arity, and that in turn
+ -- depends on deciding whether to unpack the args, and that
+ -- depends on whether it's a data type or a newtype --- so
+ -- in the recursive case we can get a loop. This version is simple!
+
+buildTyConOrClass dflags is_rec kenv rec_vrcs rec_details
+ (ForeignType {tcdName = tycon_name, tcdExtName = tycon_ext_name})
+ = ATyCon (mkForeignTyCon tycon_name tycon_ext_name liftedTypeKind 0 [])
buildTyConOrClass dflags is_rec kenv rec_vrcs rec_details
(ClassDecl {tcdName = class_name, tcdTyVars = tyvar_names,
argvrcs dict_con
clas -- Yes! It's a dictionary
flavour
+ is_rec
+ -- A class can be recursive, and in the case of newtypes
+ -- this matters. For example
+ -- class C a where { op :: C b => a -> b -> Int }
+ -- Because C has only one operation, it is represented by
+ -- a newtype, and it should be a *recursive* newtype.
+ -- [If we don't make it a recursive newtype, we'll expand the
+ -- newtype like a synonym, but that will lead toan inifinite type
ClassDetails sc_theta sc_sel_ids op_items dict_con = lookupNameEnv_NF rec_details class_name
class_kind = lookupNameEnv_NF kenv class_name
tyvars = mkTyClTyVars class_kind tyvar_names
argvrcs = lookupWithDefaultFM rec_vrcs bogusVrcs tycon
- n_fields = length sc_sel_ids + length op_items
- flavour | n_fields == 1 = NewTyCon (mkNewTyConRep tycon)
- | otherwise = DataTyCon
+ flavour = case dataConOrigArgTys dict_con of
+ -- The tyvars in the datacon are the same as in the class
+ [rep_ty] -> NewTyCon rep_ty
+ other -> DataTyCon
-- We can find the functional dependencies right away,
-- and it is vital to do so. Why? Because in the next pass
bogusVrcs = panic "Bogus tycon arg variances"
\end{code}
+\begin{code}
+mkNewTyConRep :: TyCon -- The original type constructor
+ -> Type -- Chosen representation type
+-- Find the representation type for this newtype TyCon
+-- See notes on newypes in types/TypeRep about newtypes.
+mkNewTyConRep tc = head (dataConOrigArgTys (head (tyConDataCons tc)))
+\end{code}
+
%************************************************************************
%* *
mkClassEdges :: RenamedTyClDecl -> Maybe (RenamedTyClDecl, Name, [Name])
-mkClassEdges decl@(ClassDecl {tcdCtxt = ctxt, tcdName = name}) = Just (decl, name, [c | HsPClass c _ <- ctxt])
+mkClassEdges decl@(ClassDecl {tcdCtxt = ctxt, tcdName = name}) = Just (decl, name, [c | HsClassP c _ <- ctxt])
mkClassEdges other_decl = Nothing
mkEdges :: RenamedTyClDecl -> (RenamedTyClDecl, Name, [Name])
projects / ghc-hetmet.git / blobdiff