%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
-\section[TcDeriv]{Deriving}
Handles @deriving@ clauses on @data@ declarations.
#include "HsVersions.h"
import HsSyn
-import DynFlags ( DynFlag(..) )
+import DynFlags
-import Generics ( mkTyConGenericBinds )
+import Generics
import TcRnMonad
-import TcMType ( checkValidInstance )
-import TcEnv ( newDFunName, pprInstInfoDetails,
- InstInfo(..), InstBindings(..), simpleInstInfoClsTy,
- tcLookupClass, tcLookupTyCon, tcExtendTyVarEnv
- )
+import TcMType
+import TcEnv
import TcGenDeriv -- Deriv stuff
-import InstEnv ( Instance, OverlapFlag, mkLocalInstance, instanceHead, extendInstEnvList )
-import Inst ( getOverlapFlag )
-import TcHsType ( tcHsDeriv )
-import TcSimplify ( tcSimplifyDeriv )
-
-import RnBinds ( rnMethodBinds, rnTopBinds )
-import RnEnv ( bindLocalNames )
-import HscTypes ( FixityEnv )
-
-import Class ( className, classArity, classKey, classTyVars, classSCTheta, Class )
-import Type ( zipOpenTvSubst, substTheta, pprThetaArrow, pprClassPred, mkTyVarTy )
-import ErrUtils ( dumpIfSet_dyn )
-import MkId ( mkDictFunId )
-import DataCon ( isNullarySrcDataCon, isVanillaDataCon, dataConInstOrigArgTys )
-import Maybes ( catMaybes )
-import RdrName ( RdrName )
-import Name ( Name, getSrcLoc )
-import NameSet ( duDefs )
-import Type ( splitKindFunTys )
-import TyCon ( tyConTyVars, tyConDataCons, tyConArity, tyConHasGenerics,
- tyConStupidTheta, isProductTyCon, isDataTyCon, newTyConRhs,
- isEnumerationTyCon, isRecursiveTyCon, TyCon
- )
-import TcType ( TcType, ThetaType, mkTyVarTys, mkTyConApp, tcTyConAppTyCon,
- isUnLiftedType, mkClassPred, tyVarsOfType, tyVarsOfTypes,
- isSubArgTypeKind, tcEqTypes, tcSplitAppTys, mkAppTys )
-import Var ( TyVar, tyVarKind, varName )
-import VarSet ( mkVarSet, disjointVarSet )
+import InstEnv
+import Inst
+import TcHsType
+import TcSimplify
+
+import RnBinds
+import RnEnv
+import HscTypes
+
+import Class
+import Type
+import ErrUtils
+import MkId
+import DataCon
+import Maybes
+import RdrName
+import Name
+import NameSet
+import TyCon
+import TcType
+import Var
+import VarSet
import PrelNames
-import SrcLoc ( srcLocSpan, Located(..) )
-import Util ( zipWithEqual, sortLe, notNull )
-import ListSetOps ( removeDups, assocMaybe )
+import SrcLoc
+import Util
+import ListSetOps
import Outputable
import Bag
\end{code}
So, here are the synonyms for the ``equation'' structures:
\begin{code}
-type DerivEqn = (Name, Class, TyCon, [TyVar], DerivRhs)
+type DerivEqn = (SrcSpan, InstOrigin, Name, Class, TyCon, [TyVar], DerivRhs)
-- The Name is the name for the DFun we'll build
-- The tyvars bind all the variables in the RHS
-pprDerivEqn (n,c,tc,tvs,rhs)
- = parens (hsep [ppr n, ppr c, ppr tc, ppr tvs] <+> equals <+> ppr rhs)
+pprDerivEqn :: DerivEqn -> SDoc
+pprDerivEqn (l,_,n,c,tc,tvs,rhs)
+ = parens (hsep [ppr l, ppr n, ppr c, ppr tc, ppr tvs] <+> equals <+> ppr rhs)
type DerivRhs = ThetaType
type DerivSoln = DerivRhs
\begin{code}
tcDeriving :: [LTyClDecl Name] -- All type constructors
+ -> [LDerivDecl Name] -- All stand-alone deriving declarations
-> TcM ([InstInfo], -- The generated "instance decls"
HsValBinds Name) -- Extra generated top-level bindings
-tcDeriving tycl_decls
+tcDeriving tycl_decls deriv_decls
= recoverM (returnM ([], emptyValBindsOut)) $
do { -- Fish the "deriving"-related information out of the TcEnv
-- and make the necessary "equations".
overlap_flag <- getOverlapFlag
- ; (ordinary_eqns, newtype_inst_info) <- makeDerivEqns overlap_flag tycl_decls
+ ; (ordinary_eqns, newtype_inst_info)
+ <- makeDerivEqns overlap_flag tycl_decls deriv_decls
; (ordinary_inst_info, deriv_binds)
<- extendLocalInstEnv (map iSpec newtype_inst_info) $
\begin{code}
makeDerivEqns :: OverlapFlag
-> [LTyClDecl Name]
+ -> [LDerivDecl Name]
-> TcM ([DerivEqn], -- Ordinary derivings
[InstInfo]) -- Special newtype derivings
-makeDerivEqns overlap_flag tycl_decls
- = mapAndUnzipM mk_eqn derive_these `thenM` \ (maybe_ordinaries, maybe_newtypes) ->
- returnM (catMaybes maybe_ordinaries, catMaybes maybe_newtypes)
+makeDerivEqns overlap_flag tycl_decls deriv_decls
+ = do derive_these_top_level <- mapM top_level_deriv deriv_decls >>= return . catMaybes
+ (maybe_ordinaries, maybe_newtypes)
+ <- mapAndUnzipM mk_eqn (derive_these ++ derive_these_top_level)
+ return (catMaybes maybe_ordinaries, catMaybes maybe_newtypes)
where
------------------------------------------------------------------
- derive_these :: [(NewOrData, Name, LHsType Name)]
+ derive_these :: [(SrcSpan, InstOrigin, NewOrData, Name, LHsType Name)]
-- Find the (nd, TyCon, Pred) pairs that must be `derived'
- derive_these = [ (nd, tycon, pred)
+ derive_these = [ (srcLocSpan (getSrcLoc tycon), DerivOrigin, nd, tycon, pred)
| L _ (TyData { tcdND = nd, tcdLName = L _ tycon,
tcdDerivs = Just preds }) <- tycl_decls,
pred <- preds ]
+ top_level_deriv :: LDerivDecl Name -> TcM (Maybe (SrcSpan, InstOrigin, NewOrData, Name, LHsType Name))
+ top_level_deriv d@(L l (DerivDecl inst ty_name)) = recoverM (returnM Nothing) $ setSrcSpan l $
+ do tycon <- tcLookupLocatedTyCon ty_name
+ let new_or_data = if isNewTyCon tycon then NewType else DataType
+ traceTc (text "Stand-alone deriving:" <+> ppr (new_or_data, unLoc ty_name, inst))
+ return $ Just (l, StandAloneDerivOrigin, new_or_data, unLoc ty_name, inst)
+
------------------------------------------------------------------
- mk_eqn :: (NewOrData, Name, LHsType Name) -> TcM (Maybe DerivEqn, Maybe InstInfo)
+ -- takes (whether newtype or data, name of data type, partially applied type class)
+ mk_eqn :: (SrcSpan, InstOrigin, NewOrData, Name, LHsType Name) -> TcM (Maybe DerivEqn, Maybe InstInfo)
-- We swizzle the tyvars and datacons out of the tycon
-- to make the rest of the equation
--
-- The "deriv_ty" is a LHsType to take account of the fact that for newtype derivign
-- we allow deriving (forall a. C [a]).
- mk_eqn (new_or_data, tycon_name, hs_deriv_ty)
+ mk_eqn (loc, orig, new_or_data, tycon_name, hs_deriv_ty)
= tcLookupTyCon tycon_name `thenM` \ tycon ->
- setSrcSpan (srcLocSpan (getSrcLoc tycon)) $
+ setSrcSpan loc $
addErrCtxt (derivCtxt tycon) $
tcExtendTyVarEnv (tyConTyVars tycon) $ -- Deriving preds may (now) mention
-- the type variables for the type constructor
tcHsDeriv hs_deriv_ty `thenM` \ (deriv_tvs, clas, tys) ->
doptM Opt_GlasgowExts `thenM` \ gla_exts ->
- mk_eqn_help gla_exts new_or_data tycon deriv_tvs clas tys
+ mk_eqn_help loc orig gla_exts new_or_data tycon deriv_tvs clas tys
------------------------------------------------------------------
-- data/newtype T a = ... deriving( C t1 t2 )
-- leads to a call to mk_eqn_help with
-- tycon = T, deriv_tvs = ftv(t1,t2), clas = C, tys = [t1,t2]
- mk_eqn_help gla_exts DataType tycon deriv_tvs clas tys
+ mk_eqn_help loc orig gla_exts DataType tycon deriv_tvs clas tys
| Just err <- checkSideConditions gla_exts tycon deriv_tvs clas tys
= bale_out (derivingThingErr clas tys tycon (tyConTyVars tycon) err)
| otherwise
- = do { eqn <- mkDataTypeEqn tycon clas
+ = do { eqn <- mkDataTypeEqn loc orig tycon clas
; returnM (Just eqn, Nothing) }
- mk_eqn_help gla_exts NewType tycon deriv_tvs clas tys
+ mk_eqn_help loc orig gla_exts NewType tycon deriv_tvs clas tys
| can_derive_via_isomorphism && (gla_exts || std_class_via_iso clas)
= do { traceTc (text "newtype deriving:" <+> ppr tycon <+> ppr rep_tys)
; -- Go ahead and use the isomorphism
; return (Nothing, Just (InstInfo { iSpec = mk_inst_spec dfun_name,
iBinds = NewTypeDerived ntd_info })) }
| std_class gla_exts clas
- = mk_eqn_help gla_exts DataType tycon deriv_tvs clas tys -- Go via bale-out route
+ = mk_eqn_help loc orig gla_exts DataType tycon deriv_tvs clas tys -- Go via bale-out route
| otherwise -- Non-standard instance
= bale_out (if gla_exts then
-- a suitable string; hence the empty type arg list
------------------------------------------------------------------
-mkDataTypeEqn :: TyCon -> Class -> TcM DerivEqn
-mkDataTypeEqn tycon clas
+mkDataTypeEqn :: SrcSpan -> InstOrigin -> TyCon -> Class -> TcM DerivEqn
+mkDataTypeEqn loc orig tycon clas
| clas `hasKey` typeableClassKey
= -- The Typeable class is special in several ways
-- data T a b = ... deriving( Typeable )
-- Typeable; it depends on the arity of the type
do { real_clas <- tcLookupClass (typeableClassNames !! tyConArity tycon)
; dfun_name <- new_dfun_name real_clas tycon
- ; return (dfun_name, real_clas, tycon, [], []) }
+ ; return (loc, orig, dfun_name, real_clas, tycon, [], []) }
| otherwise
= do { dfun_name <- new_dfun_name clas tycon
- ; return (dfun_name, clas, tycon, tyvars, constraints) }
+ ; return (loc, orig, dfun_name, clas, tycon, tyvars, constraints) }
where
tyvars = tyConTyVars tycon
constraints = extra_constraints ++ ordinary_constraints
iterateDeriv (n+1) new_solns
------------------------------------------------------------------
- gen_soln (_, clas, tc,tyvars,deriv_rhs)
- = setSrcSpan (srcLocSpan (getSrcLoc tc)) $
+ gen_soln :: DerivEqn -> TcM [PredType]
+ gen_soln (loc, orig, _, clas, tc,tyvars,deriv_rhs)
+ = setSrcSpan loc $
do { let inst_tys = [mkTyConApp tc (mkTyVarTys tyvars)]
; theta <- addErrCtxt (derivInstCtxt1 clas inst_tys) $
- tcSimplifyDeriv tc tyvars deriv_rhs
+ tcSimplifyDeriv orig tc tyvars deriv_rhs
; addErrCtxt (derivInstCtxt2 theta clas inst_tys) $
checkValidInstance tyvars theta clas inst_tys
; return (sortLe (<=) theta) } -- Canonicalise before returning the soluction
------------------------------------------------------------------
- mk_inst_spec (dfun_name, clas, tycon, tyvars, _) theta
+ mk_inst_spec :: DerivEqn -> DerivSoln -> Instance
+ mk_inst_spec (loc, orig, dfun_name, clas, tycon, tyvars, _) theta
= mkLocalInstance dfun overlap_flag
where
dfun = mkDictFunId dfun_name tyvars theta clas
-- It's a bit yukky that we return *renamed* InstInfo, but
-- *non-renamed* auxiliary bindings
; (rn_meth_binds, _fvs) <- discardWarnings $
- bindLocalNames (map varName tyvars) $
+ bindLocalNames (map Var.varName tyvars) $
rnMethodBinds clas_nm (\n -> []) [] meth_binds
-- Build the InstInfo
projects / ghc-hetmet.git / blobdiff