import HsSyn
import TcBinds ( mkPragFun, tcPrags, badBootDeclErr )
+import TcTyClsDecls ( tcIdxTyInstDecl )
import TcClassDcl ( tcMethodBind, mkMethodBind, badMethodErr,
tcClassDecl2, getGenericInstances )
import TcRnMonad
import InstEnv ( mkLocalInstance, instanceDFunId )
import TcDeriv ( tcDeriving )
import TcEnv ( InstInfo(..), InstBindings(..),
- newDFunName, tcExtendIdEnv
+ newDFunName, tcExtendIdEnv, tcExtendGlobalEnv
)
import TcHsType ( kcHsSigType, tcHsKindedType )
import TcUnify ( checkSigTyVars )
import TcSimplify ( tcSimplifySuperClasses )
import Type ( zipOpenTvSubst, substTheta, mkTyConApp, mkTyVarTy,
- splitFunTys )
+ splitFunTys, TyThing )
import Coercion ( mkSymCoercion )
import TyCon ( TyCon, newTyConCo, tyConTyVars )
import DataCon ( classDataCon, dataConTyCon, dataConInstArgTys )
import Outputable
import Bag
import BasicTypes ( Activation( AlwaysActive ), InlineSpec(..) )
+import HscTypes ( implicitTyThings )
import FastString
\end{code}
tcInstDecls1 tycl_decls inst_decls
= checkNoErrs $
- -- Stop if addInstInfos etc discovers any errors
- -- (they recover, so that we get more than one error each round)
-
- -- (1) Do the ordinary instance declarations
- mappM tcLocalInstDecl1 inst_decls `thenM` \ local_inst_infos ->
-
- let
- local_inst_info = catMaybes local_inst_infos
- clas_decls = filter (isClassDecl.unLoc) tycl_decls
- in
- -- (2) Instances from generic class declarations
- getGenericInstances clas_decls `thenM` \ generic_inst_info ->
-
- -- Next, construct the instance environment so far, consisting of
- -- a) local instance decls
- -- b) generic instances
- addInsts local_inst_info $
- addInsts generic_inst_info $
-
- -- (3) Compute instances from "deriving" clauses;
- -- This stuff computes a context for the derived instance decl, so it
- -- needs to know about all the instances possible; hence inst_env4
- tcDeriving tycl_decls `thenM` \ (deriv_inst_info, deriv_binds) ->
- addInsts deriv_inst_info $
-
- getGblEnv `thenM` \ gbl_env ->
- returnM (gbl_env,
- generic_inst_info ++ deriv_inst_info ++ local_inst_info,
- deriv_binds)
+ do { -- Stop if addInstInfos etc discovers any errors
+ -- (they recover, so that we get more than one error each
+ -- round)
+
+ -- (1) Do the ordinary instance declarations and instances of
+ -- indexed types
+ ; let { idxty_decls = filter (isIdxTyDecl . unLoc) tycl_decls }
+ ; local_info_tycons <- mappM tcLocalInstDecl1 inst_decls
+ ; idxty_info_tycons <- mappM tcIdxTyInstDecl idxty_decls
+
+ ; let { (local_infos,
+ local_tycons) = unzip local_info_tycons
+ ; (idxty_infos,
+ idxty_tycons) = unzip idxty_info_tycons
+ ; local_idxty_info = concat local_infos ++ catMaybes idxty_infos
+ ; local_idxty_tycon = concat local_tycons ++
+ catMaybes idxty_tycons
+ ; clas_decls = filter (isClassDecl.unLoc) tycl_decls
+ ; implicit_things = concatMap implicitTyThings local_idxty_tycon
+ }
+
+ -- (2) Add the tycons of associated types and their implicit
+ -- tythings to the global environment
+ ; tcExtendGlobalEnv (local_idxty_tycon ++ implicit_things) $ do {
+
+ -- (3) Instances from generic class declarations
+ ; generic_inst_info <- getGenericInstances clas_decls
+
+ -- Next, construct the instance environment so far, consisting
+ -- of
+ -- a) local instance decls
+ -- b) generic instances
+ ; addInsts local_idxty_info $ do {
+ ; addInsts generic_inst_info $ do {
+
+ -- (4) Compute instances from "deriving" clauses;
+ -- This stuff computes a context for the derived instance
+ -- decl, so it needs to know about all the instances possible
+ ; (deriv_inst_info, deriv_binds) <- tcDeriving tycl_decls
+ ; addInsts deriv_inst_info $ do {
+
+ ; gbl_env <- getGblEnv
+ ; returnM (gbl_env,
+ generic_inst_info ++ deriv_inst_info ++ local_idxty_info,
+ deriv_binds)
+ }}}}}
addInsts :: [InstInfo] -> TcM a -> TcM a
addInsts infos thing_inside
\begin{code}
tcLocalInstDecl1 :: LInstDecl Name
- -> TcM (Maybe InstInfo) -- Nothing if there was an error
+ -> TcM ([InstInfo], [TyThing]) -- [] if there was an error
-- A source-file instance declaration
-- Type-check all the stuff before the "where"
--
-- We check for respectable instance type, and context
tcLocalInstDecl1 decl@(L loc (InstDecl poly_ty binds uprags ats))
- -- !!!TODO: Handle the `ats' parameter!!! -=chak
= -- Prime error recovery, set source location
- recoverM (returnM Nothing) $
+ recoverM (returnM ([], [])) $
setSrcSpan loc $
addErrCtxt (instDeclCtxt1 poly_ty) $
; poly_ty' <- tcHsKindedType kinded_ty
; let (tyvars, theta, tau) = tcSplitSigmaTy poly_ty'
+ -- Now, check the validity of the instance.
; (clas, inst_tys) <- checkValidInstHead tau
; checkValidInstance tyvars theta clas inst_tys
+ -- Next, process any associated types.
+ ; idxty_info_tycons <- mappM tcIdxTyInstDecl ats
+
+ -- Finally, construct the Core representation of the instance.
+ -- (This no longer includes the associated types.)
; dfun_name <- newDFunName clas inst_tys (srcSpanStart loc)
; overlap_flag <- getOverlapFlag
- ; let dfun = mkDictFunId dfun_name tyvars theta clas inst_tys
- ispec = mkLocalInstance dfun overlap_flag
-
- ; return (Just (InstInfo { iSpec = ispec, iBinds = VanillaInst binds uprags })) }
+ ; let dfun = mkDictFunId dfun_name tyvars theta clas inst_tys
+ ispec = mkLocalInstance dfun overlap_flag
+ (idxty_infos,
+ idxty_tycons) = unzip idxty_info_tycons
+
+ ; return ([InstInfo { iSpec = ispec,
+ iBinds = VanillaInst binds uprags }] ++
+ catMaybes idxty_infos,
+ catMaybes idxty_tycons)
+ }
\end{code}
projects / ghc-hetmet.git / blobdiff