Handles @deriving@ clauses on @data@ declarations.
\begin{code}
-#include "HsVersions.h"
-
module TcDeriv ( tcDeriving ) where
-IMP_Ubiq()
+#include "HsVersions.h"
-import HsSyn ( HsDecl, FixityDecl, Fixity, InstDecl,
- Sig, HsBinds(..), MonoBinds(..),
- GRHSsAndBinds, Match, HsExpr, HsLit, InPat,
- ArithSeqInfo, Fake, HsType,
- collectMonoBinders
- )
-import HsPragmas ( InstancePragmas(..) )
-import RdrHsSyn ( RdrName, SYN_IE(RdrNameMonoBinds) )
-import RnHsSyn ( SYN_IE(RenamedHsBinds), SYN_IE(RenamedMonoBinds), SYN_IE(RenamedFixityDecl) )
-import TcHsSyn ( TcIdOcc )
+import HsSyn ( HsBinds(..), MonoBinds(..), collectMonoBinders )
+import RdrHsSyn ( RdrName, RdrNameMonoBinds )
+import RnHsSyn ( RenamedHsBinds, RenamedMonoBinds )
import TcMonad
-import Inst ( SYN_IE(InstanceMapper) )
+import Inst ( InstanceMapper )
import TcEnv ( getEnv_TyCons, tcLookupClassByKey )
-import SpecEnv ( SpecEnv )
import TcKind ( TcKind )
import TcGenDeriv -- Deriv stuff
import TcInstUtil ( InstInfo(..), mkInstanceRelatedIds, buildInstanceEnvs )
import RnBinds ( rnMethodBinds, rnTopMonoBinds )
import RnEnv ( newDfunName, bindLocatedLocalsRn )
-import RnMonad ( SYN_IE(RnM), RnDown, GDown, SDown, RnNameSupply(..),
- setNameSupplyRn, renameSourceCode, thenRn, mapRn, returnRn )
-
-import Bag ( Bag, isEmptyBag, unionBags, listToBag )
-import Class ( classKey, GenClass, SYN_IE(Class) )
-import ErrUtils ( pprBagOfErrors, addErrLoc, SYN_IE(Error) )
-import Id ( dataConArgTys, isNullaryDataCon, mkDictFunId )
+import RnMonad ( RnM, RnDown, SDown, RnNameSupply(..),
+ renameSourceCode, thenRn, mapRn, returnRn )
+
+import Bag ( Bag, emptyBag, unionBags, listToBag )
+import Class ( classKey, Class )
+import ErrUtils ( ErrMsg )
+import MkId ( mkDictFunId )
+import Id ( dataConArgTys, isNullaryDataCon )
import PrelInfo ( needsDataDeclCtxtClassKeys )
import Maybes ( maybeToBool )
-import Name ( isLocallyDefined, getSrcLoc, ExportFlag(..), Provenance,
- Name{--O only-}, SYN_IE(Module)
+import Name ( isLocallyDefined, getSrcLoc, Provenance,
+ Name{--O only-}, Module, NamedThing(..),
+ OccName, nameOccName
)
-import Outputable ( PprStyle(..), Outputable(..){-instances e.g., (,)-} )
-import PprType ( GenType, GenTyVar, GenClass, TyCon )
-import Pretty ( ($$), vcat, hsep, hcat,
- ptext, text, char, hang, Doc )
import SrcLoc ( mkGeneratedSrcLoc, SrcLoc )
import TyCon ( tyConTyVars, tyConDataCons, tyConDerivings,
tyConTheta, maybeTyConSingleCon, isDataTyCon,
isEnumerationTyCon, isAlgTyCon, TyCon
)
-import Type ( GenType(..), SYN_IE(TauType), mkTyVarTys, applyTyCon,
- mkSigmaTy, mkDictTy, isPrimType, instantiateTy,
- getAppDataTyCon, getAppTyCon
+import Type ( GenType(..), TauType, mkTyVarTys, mkTyConApp,
+ mkSigmaTy, mkDictTy, isUnboxedType,
+ splitAlgTyConApp
)
import TysPrim ( voidTy )
-import TyVar ( GenTyVar, SYN_IE(TyVar) )
-import UniqFM ( emptyUFM )
+import TyVar ( GenTyVar, TyVar )
import Unique -- Keys stuff
import Bag ( bagToList )
-import Util ( zipWithEqual, zipEqual, sortLt, removeDups, assoc,
- thenCmp, cmpList, panic, panic#, pprPanic, pprPanic#,
- Ord3(..), assertPanic-- , pprTrace{-ToDo:rm-}
-
- )
+import Util ( zipWithEqual, sortLt, removeDups, assoc, thenCmp )
+import Outputable
\end{code}
%************************************************************************
-- NEW: it's convenient to re-use InstInfo
-- We'll "panic" out some fields...
-type DerivRhs = [(Class, TauType)] -- Same as a ThetaType!
+type DerivRhs = [(Class, [TauType])] -- Same as a ThetaType!
type DerivSoln = DerivRhs
\end{code}
-> Bag InstInfo -- What we already know about instances
-> TcM s (Bag InstInfo, -- The generated "instance decls".
RenamedHsBinds, -- Extra generated bindings
- PprStyle -> Doc) -- Printable derived instance decls;
+ SDoc) -- Printable derived instance decls;
-- for debugging via -ddump-derivings.
tcDeriving modname rn_name_supply inst_decl_infos_in
- = -- Fish the "deriving"-related information out of the TcEnv
+ = recoverTc (returnTc (emptyBag, EmptyBinds, empty)) $
+
+ -- Fish the "deriving"-related information out of the TcEnv
-- and make the necessary "equations".
makeDerivEqns `thenTc` \ eqns ->
+ if null eqns then
+ returnTc (emptyBag, EmptyBinds, text "No derivings")
+ else
-- Take the equation list and solve it, to deliver a list of
-- solutions, a.k.a. the contexts for the instance decls
-- method bindings for the instances.
(dfun_names_w_method_binds, rn_extra_binds)
= renameSourceCode modname rn_name_supply (
- bindLocatedLocalsRn (\_ -> text "deriving") mbinders $ \ _ ->
+ bindLocatedLocalsRn (ptext (SLIT("deriving"))) mbinders $ \ _ ->
rnTopMonoBinds extra_mbinds [] `thenRn` \ rn_extra_binds ->
mapRn rn_one method_binds_s `thenRn` \ dfun_names_w_method_binds ->
returnRn (dfun_names_w_method_binds, rn_extra_binds)
)
- rn_one meth_binds = newDfunName Nothing mkGeneratedSrcLoc `thenRn` \ dfun_name ->
- rnMethodBinds meth_binds `thenRn` \ rn_meth_binds ->
- returnRn (dfun_name, rn_meth_binds)
+ rn_one (cl_nm, tycon_nm, meth_binds)
+ = newDfunName cl_nm tycon_nm
+ Nothing mkGeneratedSrcLoc `thenRn` \ dfun_name ->
+ rnMethodBinds meth_binds `thenRn` \ rn_meth_binds ->
+ returnRn (dfun_name, rn_meth_binds)
really_new_inst_infos = map (gen_inst_info modname)
(new_inst_infos `zip` dfun_names_w_method_binds)
ddump_deriv = ddump_deriving really_new_inst_infos rn_extra_binds
in
- --pprTrace "derived:\n" (ddump_deriv PprDebug) $
+ --pprTrace "derived:\n" (ddump_deriv) $
returnTc (listToBag really_new_inst_infos,
rn_extra_binds,
ddump_deriv)
where
- ddump_deriving :: [InstInfo] -> RenamedHsBinds -> (PprStyle -> Doc)
+ ddump_deriving :: [InstInfo] -> RenamedHsBinds -> SDoc
- ddump_deriving inst_infos extra_binds sty
- = vcat ((map pp_info inst_infos) ++ [ppr sty extra_binds])
+ ddump_deriving inst_infos extra_binds
+ = vcat ((map pp_info inst_infos) ++ [ppr extra_binds])
where
- pp_info (InstInfo clas tvs ty inst_decl_theta _ _ mbinds _ _)
- = ($$) (ppr sty (mkSigmaTy tvs inst_decl_theta (mkDictTy clas ty)))
- (ppr sty mbinds)
+ pp_info (InstInfo clas tvs [ty] inst_decl_theta _ _ mbinds _ _)
+ = ($$) (ppr (mkSigmaTy tvs inst_decl_theta (mkDictTy clas [ty])))
+ (ppr mbinds)
\end{code}
is_enumeration = isEnumerationTyCon tycon
is_single_con = maybeToBool (maybeTyConSingleCon tycon)
- chk_clas clas_uniq clas_str cond
+ single_nullary_why = SLIT("one constructor data type or type with all nullary constructors expected")
+ nullary_why = SLIT("data type with all nullary constructors expected")
+
+ chk_clas clas_uniq clas_str clas_why cond
= if (clas_uniq == clas_key)
- then checkTc cond (derivingThingErr clas_str tycon)
+ then checkTc cond (derivingThingErr clas_str clas_why tycon)
else returnTc ()
in
-- Are things OK for deriving Enum (if appropriate)?
- chk_clas enumClassKey "Enum" is_enumeration `thenTc_`
+ chk_clas enumClassKey (SLIT("Enum")) nullary_why is_enumeration `thenTc_`
-- Are things OK for deriving Bounded (if appropriate)?
- chk_clas boundedClassKey "Bounded"
- (is_enumeration || is_single_con) `thenTc_`
+ chk_clas boundedClassKey (SLIT("Bounded")) single_nullary_why
+ (is_enumeration || is_single_con) `thenTc_`
-- Are things OK for deriving Ix (if appropriate)?
- chk_clas ixClassKey "Ix.Ix" (is_enumeration || is_single_con)
+ chk_clas ixClassKey (SLIT("Ix.Ix")) single_nullary_why
+ (is_enumeration || is_single_con)
------------------------------------------------------------------
- cmp_deriv :: (Class, TyCon) -> (Class, TyCon) -> TAG_
+ cmp_deriv :: (Class, TyCon) -> (Class, TyCon) -> Ordering
cmp_deriv (c1, t1) (c2, t2)
- = (c1 `cmp` c2) `thenCmp` (t1 `cmp` t2)
+ = (c1 `compare` c2) `thenCmp` (t1 `compare` t2)
------------------------------------------------------------------
mk_eqn :: (Class, TyCon) -> DerivEqn
offensive_class = clas_key `elem` needsDataDeclCtxtClassKeys
mk_constraints data_con
- = [ (clas, arg_ty)
+ = [ (clas, [arg_ty])
| arg_ty <- instd_arg_tys,
- not (isPrimType arg_ty) -- No constraints for primitive types
+ not (isUnboxedType arg_ty) -- No constraints for unboxed types?
]
where
instd_arg_tys = dataConArgTys data_con tyvar_tys
initial_solutions :: [DerivSoln]
initial_solutions = [ [] | _ <- orig_eqns ]
+ ------------------------------------------------------------------
-- iterateDeriv calculates the next batch of solutions,
-- compares it with the current one; finishes if they are the
-- same, otherwise recurses with the new solutions.
-
+ -- It fails if any iteration fails
iterateDeriv :: [DerivSoln] ->TcM s [InstInfo]
-
iterateDeriv current_solns
+ = checkNoErrsTc (iterateOnce current_solns) `thenTc` \ (new_inst_infos, new_solns) ->
+ if (current_solns == new_solns) then
+ returnTc new_inst_infos
+ else
+ iterateDeriv new_solns
+
+ ------------------------------------------------------------------
+ iterateOnce current_solns
= -- Extend the inst info from the explicit instance decls
-- with the current set of solutions, giving a
add_solns inst_decl_infos_in orig_eqns current_solns
- `thenTc` \ (new_inst_infos, inst_mapper) ->
+ `thenNF_Tc` \ (new_inst_infos, inst_mapper) ->
let
class_to_inst_env cls = inst_mapper cls
in
-- Simplify each RHS
- listTc [ tcSimplifyThetas class_to_inst_env [{-Nothing "given"-}] deriv_rhs
- | (_,_,_,deriv_rhs) <- orig_eqns ] `thenTc` \ next_solns ->
+ listTc [ tcAddErrCtxt (derivCtxt tc) $
+ tcSimplifyThetas class_to_inst_env deriv_rhs
+ | (_,tc,_,deriv_rhs) <- orig_eqns ] `thenTc` \ next_solns ->
-- Canonicalise the solutions, so they compare nicely
let canonicalised_next_solns
- = [ sortLt lt_rhs next_soln | next_soln <- next_solns ] in
-
- if (current_solns `eq_solns` canonicalised_next_solns) then
- returnTc new_inst_infos
- else
- iterateDeriv canonicalised_next_solns
-
- where
- ------------------------------------------------------------------
- lt_rhs r1 r2 = case cmp_rhs r1 r2 of { LT_ -> True; _ -> False }
- eq_solns s1 s2 = case cmp_solns s1 s2 of { EQ_ -> True; _ -> False }
- cmp_solns s1 s2 = cmpList (cmpList cmp_rhs) s1 s2
- cmp_rhs (c1, TyVarTy tv1) (c2, TyVarTy tv2)
- = (tv1 `cmp` tv2) `thenCmp` (c1 `cmp` c2)
-#ifdef DEBUG
- cmp_rhs other_1 other_2
- = panic# "tcDeriv:cmp_rhs:" --(hsep [ppr PprDebug other_1, ppr PprDebug other_2])
-#endif
-
+ = [ sortLt (<) next_soln | next_soln <- next_solns ]
+ in
+ returnTc (new_inst_infos, canonicalised_next_solns)
\end{code}
\begin{code}
add_solns :: Bag InstInfo -- The global, non-derived ones
-> [DerivEqn] -> [DerivSoln]
- -> TcM s ([InstInfo], -- The new, derived ones
- InstanceMapper)
+ -> NF_TcM s ([InstInfo], -- The new, derived ones
+ InstanceMapper)
-- the eqns and solns move "in lockstep"; we have the eqns
-- because we need the LHS info for addClassInstance.
add_solns inst_infos_in eqns solns
- = discardErrsTc (buildInstanceEnvs all_inst_infos) `thenTc` \ inst_mapper ->
+
+ = discardErrsTc (buildInstanceEnvs all_inst_infos) `thenNF_Tc` \ inst_mapper ->
-- We do the discard-errs so that we don't get repeated error messages
- -- about missing or duplicate instances.
- returnTc (new_inst_infos, inst_mapper)
+ -- about duplicate instances.
+ -- They'll appear later, when we do the top-level buildInstanceEnvs.
+
+ returnNF_Tc (new_inst_infos, inst_mapper)
where
new_inst_infos = zipWithEqual "add_solns" mk_deriv_inst_info eqns solns
all_inst_infos = inst_infos_in `unionBags` listToBag new_inst_infos
mk_deriv_inst_info (clas, tycon, tyvars, _) theta
- = InstInfo clas tyvars (applyTyCon tycon (mkTyVarTys tyvars))
+ = InstInfo clas tyvars [mkTyConApp tycon (mkTyVarTys tyvars)]
theta
(my_panic "dfun_theta")
(my_panic "upragmas")
where
dummy_dfun_id
- = mkDictFunId bottom dummy_dfun_ty bottom bottom
+ = mkDictFunId (getName tycon) dummy_dfun_ty bottom bottom
+ -- The name is getSrcLoc'd in an error message
where
bottom = panic "dummy_dfun_id"
-- We can't leave it as a panic because to get the theta part we
-- have to run down the type!
- my_panic str = panic "add_soln" -- pprPanic ("add_soln:"++str) (hsep [char ':', ppr PprDebug clas, ppr PprDebug tycon])
+ my_panic str = panic "add_soln" -- pprPanic ("add_soln:"++str) (hsep [char ':', ppr clas, ppr tycon])
\end{code}
%************************************************************************
\begin{code}
-- Generate the method bindings for the required instance
-gen_bind :: InstInfo -> RdrNameMonoBinds
-gen_bind (InstInfo clas _ ty _ _ _ _ _ _)
+-- (paired with class name, as we need that when generating dict
+-- names.)
+gen_bind :: InstInfo -> ({-class-}OccName, {-tyCon-}OccName, RdrNameMonoBinds)
+gen_bind (InstInfo clas _ [ty] _ _ _ _ _ _)
| not from_here
- = EmptyMonoBinds
+ = (clas_nm, tycon_nm, EmptyMonoBinds)
| otherwise
- = assoc "gen_inst_info:bad derived class"
- [(eqClassKey, gen_Eq_binds)
- ,(ordClassKey, gen_Ord_binds)
- ,(enumClassKey, gen_Enum_binds)
- ,(evalClassKey, gen_Eval_binds)
- ,(boundedClassKey, gen_Bounded_binds)
- ,(showClassKey, gen_Show_binds)
- ,(readClassKey, gen_Read_binds)
- ,(ixClassKey, gen_Ix_binds)
- ]
- (classKey clas)
- tycon
+ = (clas_nm, tycon_nm,
+ assoc "gen_bind:bad derived class"
+ [(eqClassKey, gen_Eq_binds)
+ ,(ordClassKey, gen_Ord_binds)
+ ,(enumClassKey, gen_Enum_binds)
+ ,(evalClassKey, gen_Eval_binds)
+ ,(boundedClassKey, gen_Bounded_binds)
+ ,(showClassKey, gen_Show_binds)
+ ,(readClassKey, gen_Read_binds)
+ ,(ixClassKey, gen_Ix_binds)
+ ]
+ (classKey clas)
+ tycon)
where
+ clas_nm = nameOccName (getName clas)
+ tycon_nm = nameOccName (getName tycon)
from_here = isLocallyDefined tycon
- (tycon,_,_) = getAppDataTyCon ty
+ (tycon,_,_) = splitAlgTyConApp ty
gen_inst_info :: Module -- Module name
-> InstInfo -- the gen'd (filled-in) "instance decl"
gen_inst_info modname
- (InstInfo clas tyvars ty inst_decl_theta _ _ _ locn _, (dfun_name, meth_binds))
+ (InstInfo clas tyvars tys@(ty:_) inst_decl_theta _ _ _ locn _, (dfun_name, meth_binds))
=
-- Generate the various instance-related Ids
- InstInfo clas tyvars ty inst_decl_theta
+ InstInfo clas tyvars tys inst_decl_theta
dfun_theta dfun_id
meth_binds
locn []
where
(dfun_id, dfun_theta) = mkInstanceRelatedIds
dfun_name
- clas tyvars ty
+ clas tyvars tys
inst_decl_theta
from_here = isLocallyDefined tycon
- (tycon,_,_) = getAppDataTyCon ty
+ (tycon,_,_) = splitAlgTyConApp ty
\end{code}
TagThingWanted)]
gen_taggery_Names inst_infos
- = --pprTrace "gen_taggery:\n" (vcat [hsep [ppr PprDebug c, ppr PprDebug t] | (c,t) <- all_CTs]) $
+ = --pprTrace "gen_taggery:\n" (vcat [hsep [ppr c, ppr t] | (c,t) <- all_CTs]) $
foldlTc do_con2tag [] tycons_of_interest `thenTc` \ names_so_far ->
foldlTc do_tag2con names_so_far tycons_of_interest
where
- all_CTs = [ mk_CT c ty | (InstInfo c _ ty _ _ _ _ _ _) <- inst_infos ]
+ all_CTs = [ (c, get_tycon ty) | (InstInfo c _ [ty] _ _ _ _ _ _) <- inst_infos ]
- mk_CT c ty = (c, fst (getAppTyCon ty))
+ get_tycon ty = case splitAlgTyConApp ty of { (tc, _, _) -> tc }
all_tycons = map snd all_CTs
- (tycons_of_interest, _) = removeDups cmp all_tycons
+ (tycons_of_interest, _) = removeDups compare all_tycons
do_con2tag acc_Names tycon
| isDataTyCon tycon &&
\end{code}
\begin{code}
-derivingThingErr :: String -> TyCon -> Error
+derivingThingErr :: FAST_STRING -> FAST_STRING -> TyCon -> ErrMsg
+
+derivingThingErr thing why tycon
+ = hang (hsep [ptext SLIT("Can't make a derived instance of"), ptext thing])
+ 0 (hang (hsep [ptext SLIT("for the type"), quotes (ppr tycon)])
+ 0 (parens (ptext why)))
-derivingThingErr thing tycon sty
- = hang (hsep [ptext SLIT("Can't make a derived instance of"), text thing])
- 4 (hsep [ptext SLIT("for the type"), ppr sty tycon])
+derivCtxt tycon
+ = ptext SLIT("When deriving classes for") <+> quotes (ppr tycon)
\end{code}
projects / ghc-hetmet.git / blobdiff