%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1995
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcModule]{Typechecking a whole module}
\begin{code}
-#include "HsVersions.h"
-
module TcModule (
- tcModule,
-
- -- to make the interface self-sufficient...
- Module, Bag, CE(..), E, Binds, FixityDecl, Expr, InPat,
- RenamedPat(..), TypecheckedPat, Id, Inst, Maybe, TcResult,
- Name, ProtoName, SrcLoc, Subst, TCE(..), UniqFM,
- Error(..), Pretty(..), PprStyle, PrettyRep, InstInfo
+ typecheckModule,
+ TcResults(..)
) where
-import TcMonad -- typechecking monad machinery
-import AbsSyn -- the stuff being typechecked
+#include "HsVersions.h"
--- OLD:
---import AbsPrel ( stringTy,
--- eqStringId, neStringId, ltStringId,
--- leStringId, geStringId, gtStringId,
--- maxStringId, minStringId, tagCmpStringId,
--- dfunEqStringId, dfunOrdStringId,
--- pRELUDE_CORE
--- IF_ATTACK_PRAGMAS(COMMA mkListTy COMMA charTy)
--- )
---#if USE_ATTACK_PRAGMAS
---import PrelVals ( string_cmp_id ) -- shouldn't even be visible, really
---#endif
-import BackSubst ( applyTcSubstToBinds )
-import Bag ( unionBags, bagToList, emptyBag, listToBag )
-import CE ( nullCE, checkClassCycles, lookupCE, CE(..) )
-import CmdLineOpts ( GlobalSwitch(..) )
-import E
-import HsCore -- ****** NEED TO SEE CONSTRUCTORS ******
-import HsPragmas -- ****** NEED TO SEE CONSTRUCTORS ******
-import InstEnv
-import LIE ( unMkLIE, plusLIE, LIE )
-import Name ( Name(..) )
-import RenameAuxFuns ( GlobalNameFuns(..), GlobalNameFun(..), ProtoName, Maybe )
-import SrcLoc ( mkBuiltinSrcLoc, SrcLoc )
-import TCE ( checkTypeCycles, TCE(..), UniqFM )
-import TcBinds ( tcTopBindsAndThen )
-import TcClassDcl ( tcClassDecls1, tcClassDecls2, ClassInfo )
+import CmdLineOpts ( DynFlag(..), DynFlags, opt_PprStyle_Debug )
+import HsSyn ( HsModule(..), HsBinds(..), MonoBinds(..), HsDecl(..) )
+import HsTypes ( toHsType )
+import RnHsSyn ( RenamedHsModule, RenamedHsDecl )
+import TcHsSyn ( TypecheckedMonoBinds,
+ TypecheckedForeignDecl, TypecheckedRuleDecl,
+ zonkTopBinds, zonkForeignExports, zonkRules
+ )
+
+import TcMonad
+import Inst ( emptyLIE, plusLIE )
+import TcBinds ( tcTopBinds )
+import TcClassDcl ( tcClassDecls2, mkImplicitClassBinds )
import TcDefaults ( tcDefaults )
-import TcDeriv ( tcDeriving )
+import TcEnv ( TcEnv, tcExtendGlobalValEnv, tcLookupGlobal_maybe,
+ tcEnvTyCons, tcEnvClasses,
+ tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv
+ )
+import TcRules ( tcRules )
+import TcForeign ( tcForeignImports, tcForeignExports )
import TcIfaceSig ( tcInterfaceSigs )
-import TcInstDcls ( tcInstDecls1, tcInstDecls2, tcSpecInstSigs, buildInstanceEnvs, InstInfo(..) )
+import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
+import InstEnv ( InstInfo(..) )
import TcSimplify ( tcSimplifyTop )
-import TcTyDecls ( tcTyDecls )
-import Unique -- some ClassKey stuff
-import UniqFM ( emptyUFM ) -- profiling, pragmas only
+import TcTyClsDecls ( tcTyAndClassDecls )
+import TcTyDecls ( mkImplicitDataBinds )
+
+import CoreUnfold ( unfoldingTemplate )
+import Type ( funResultTy, splitForAllTys )
+import Bag ( isEmptyBag )
+import ErrUtils ( printErrorsAndWarnings, dumpIfSet_dyn )
+import Id ( idType, idName, idUnfolding )
+import Module ( Module, moduleName, plusModuleEnv )
+import Name ( Name, nameOccName, isLocallyDefined, isGlobalName,
+ toRdrName, nameEnvElts, emptyNameEnv, lookupNameEnv
+ )
+import TyCon ( TyCon, isDataTyCon, tyConName, tyConGenInfo )
+import OccName ( isSysOcc )
+import TyCon ( TyCon, isClassTyCon )
+import Class ( Class )
+import PrelNames ( mAIN_Name, mainName )
+import UniqSupply ( UniqSupply )
+import Maybes ( maybeToBool, thenMaybe )
import Util
-
-import Pretty -- Debugging
+import BasicTypes ( EP(..), Fixity )
+import Bag ( Bag, isEmptyBag )
+import Outputable
+import HscTypes ( PersistentCompilerState(..), HomeSymbolTable, HomeIfaceTable,
+ PackageSymbolTable, PackageIfaceTable, DFunId, ModIface(..),
+ TypeEnv, extendTypeEnv, lookupTable,
+ TyThing(..), groupTyThings )
+import FiniteMap ( FiniteMap, delFromFM, lookupWithDefaultFM )
\end{code}
+Outside-world interface:
\begin{code}
-tcModule :: E -- initial typechecker environment
- -> GlobalNameFuns -- final renamer info (to do derivings)
- -> RenamedModule -- input
- -> TcM ((TypecheckedBinds, -- binds from class decls; does NOT
- -- include default-methods bindings
- TypecheckedBinds, -- binds from instance decls; INCLUDES
- -- class default-methods binds
- TypecheckedBinds, -- binds from value decls
- [(Inst, TypecheckedExpr)]),
-
- ([RenamedFixityDecl], -- things for the interface generator
- [Id], -- to look at...
- CE,
- TCE,
- Bag InstInfo),
- FiniteMap TyCon [[Maybe UniType]],
- -- source tycon specialisation requests
-
---UNUSED: E, -- environment of total accumulated info
- E, -- environment of info due to this module only
- PprStyle -> Pretty) -- -ddump-deriving info (passed upwards)
-
-tcModule e1 renamer_name_funs
- (Module mod_name exports imports_should_be_empty fixities
- tydecls ty_sigs classdecls instdecls specinst_sigs
- default_decls valdecls sigs src_loc)
-
- = addSrcLocTc src_loc ( -- record where we're starting
-
- -- Tie the knot for inteface-file value declaration signatures
- -- This info is only used inside the knot for type-checking the
- -- pragmas, which is done lazily [ie failure just drops the pragma
- -- without having any global-failure effect].
+-- Convenient type synonyms first:
+data TcResults
+ = TcResults {
+ tc_pcs :: PersistentCompilerState, -- Augmented with imported information,
+ -- (but not stuff from this module)
+ tc_env :: TypeEnv, -- The TypeEnv just for the stuff from this module
+ tc_insts :: [DFunId], -- Instances, just for this module
+ tc_binds :: TypecheckedMonoBinds,
+ tc_fords :: [TypecheckedForeignDecl], -- Foreign import & exports.
+ tc_rules :: [TypecheckedRuleDecl] -- Transformation rules
+ }
+
+---------------
+typecheckModule
+ :: DynFlags
+ -> Module
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> HomeIfaceTable
+ -> PackageIfaceTable
+ -> RenamedHsModule
+ -> IO (Maybe (TcEnv, TcResults))
+
+typecheckModule dflags this_mod pcs hst hit pit (HsModule mod_name _ _ _ decls _ src_loc)
+ = do env <- initTcEnv global_symbol_table
+ (maybe_result, (errs,warns)) <- initTc dflags env src_loc tc_module
+ printErrorsAndWarnings (errs,warns)
+ printTcDump dflags maybe_result
+ if isEmptyBag errs then
+ return Nothing
+ else
+ return maybe_result
+ where
+ global_symbol_table = pcs_PST pcs `plusModuleEnv` hst
+
+ tc_module = fixTc (\ ~(unf_env ,_)
+ -> tcModule pcs hst get_fixity this_mod decls unf_env)
+
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity nm = lookupTable hit pit nm `thenMaybe` \ iface ->
+ lookupNameEnv (mi_fixities iface) nm
+\end{code}
- fixTc (\ ~(rec_gve_sigs, _, _, _, _, _, _, _, _, _) ->
+The internal monster:
+\begin{code}
+tcModule :: PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> TcEnv -- The knot-tied environment
+ -> TcM (TcEnv, TcResults)
+
+ -- (unf_env :: TcEnv) is used for type-checking interface pragmas
+ -- which is done lazily [ie failure just drops the pragma
+ -- without having any global-failure effect].
+ --
+ -- unf_env is also used to get the pragama info
+ -- for imported dfuns and default methods
+
+tcModule pcs hst get_fixity this_mod decls unf_env
+ = -- Type-check the type and class decls
+ tcTyAndClassDecls unf_env decls `thenTc` \ env ->
+ tcSetEnv env $
let
- e2 = plusE_GVE e1 rec_gve_sigs
+ classes = tcEnvClasses env
+ tycons = tcEnvTyCons env -- INCLUDES tycons derived from classes
+ local_classes = filter isLocallyDefined classes
+ local_tycons = [ tc | tc <- tycons,
+ isLocallyDefined tc,
+ not (isClassTyCon tc)
+ ]
+ -- For local_tycons, filter out the ones derived from classes
+ -- Otherwise the latter show up in interface files
in
-
- -- The knot for instance information. This isn't used at all
- -- till we type-check value declarations.
- fixTc ( \ ~(rec_inst_mapper, _, _, _, _, _, _, _, _) ->
-
- -- The knot for TyCons and Classes
- fixTc ( \ ~(_, rec_tce, rec_ce, rec_datacons_gve, rec_ops_gve, _, _) ->
- let
- e3 = e2
- `plusE_GVE` rec_datacons_gve
- `plusE_GVE` rec_ops_gve
- `plusE_TCE` rec_tce
- `plusE_CE` rec_ce
- in
- -- DO THE TYPE DECLS
- -- Including the pragmas: {-# ABSTRACT TypeSyn #-}
- -- {-# SPECIALIZE data DataType ... #-}
- let
- (absty_sigs, specdata_sigs) = partition is_absty_sig ty_sigs
- is_absty_sig (AbstractTypeSig _ _) = True
- is_absty_sig (SpecDataSig _ _ _) = False
-
- is_abs_syn :: Name -> Bool -- a lookup fn for abs synonyms
- is_abs_syn n
- = n `is_elem` [ tc | (AbstractTypeSig tc _) <- absty_sigs ]
- where
- is_elem = isIn "tcModule"
-
- get_spec_sigs :: Name -> [RenamedDataTypeSig]
- get_spec_sigs n
- = [ sig | sig@(SpecDataSig tc _ _) <- specdata_sigs, n == tc]
- in
- babyTcMtoTcM (tcTyDecls e3 is_abs_syn get_spec_sigs tydecls)
- `thenTc` \ (tce, datacons_gve, tycon_specs) ->
-
- -- DO THE CLASS DECLS
- tcClassDecls1 e3 rec_inst_mapper classdecls
- `thenTc` \ (class_info, ce, ops_gve) ->
-
- -- End of TyCon/Class knot
- -- Augment whatever TCE/GVE/CE stuff was in orig_e
- returnTc (e3, tce, ce, datacons_gve, ops_gve, class_info, tycon_specs)
-
- -- End of inner fixTc
- ) `thenTc` ( \ (e3, tce_here, ce_here, _, _, class_info, tycon_specs) ->
- -- The "here" things are the extra decls defined in this
- -- module or its imports; but not including whatever was
- -- in the incoming e.
-
- -- Grab completed tce/ce and check for type/class cycles
- -- The tce/ce are now stable and lookable-at, with the
- -- exception of the instance information inside classes
- let
- ce3 = getE_CE e3
- tce3 = getE_TCE e3
- in
- checkMaybeErrTc (checkTypeCycles tce3) id `thenTc_`
- checkMaybeErrTc (checkClassCycles ce3) id `thenTc_`
-
- -- Now instance declarations
- tcInstDecls1 e3 ce3 tce3 instdecls `thenNF_Tc` \ decl_inst_info ->
-
- -- Handle "derived" instances; note that we only do derivings
- -- for things in this module; we ignore deriving decls from
- -- interfaces! We pass fixities, because they may be used in
- -- doing Text.
-
- tcDeriving mod_name renamer_name_funs decl_inst_info tce3 fixities
- `thenTc` \ (deriv_inst_info, extra_deriv_binds, ddump_deriv) ->
-
- let
- inst_info = deriv_inst_info `unionBags` decl_inst_info
- in
- -- Handle specialise instance pragmas
--- getSwitchCheckerTc `thenNF_Tc` \ sw_chkr ->
--- (if sw_chkr GlasgowExts then
- tcSpecInstSigs e3 ce3 tce3 inst_info specinst_sigs
--- else
--- returnTc emptyBag)
- `thenTc` \ spec_inst_info ->
- let
- full_inst_info = inst_info `unionBags` spec_inst_info
- in
- -- OK, now do the inst-mapper stuff
- buildInstanceEnvs full_inst_info `thenTc` \ all_insts_mapper ->
-
- returnTc (all_insts_mapper, e3, ce_here, tce_here, class_info, tycon_specs,
- full_inst_info, extra_deriv_binds, ddump_deriv)
-
- -- End of outer fixTc
- )) `thenTc` ( \ (_, e3, ce_here, tce_here, class_info, tycon_specs,
- full_inst_info, extra_deriv_binds, ddump_deriv) ->
-
- -- Default declarations
- tcDefaults e3 default_decls `thenTc` \ defaulting_tys ->
- setDefaultingTys defaulting_tys ( -- for the iface sigs...
-
+
+ -- Typecheck the instance decls, includes deriving
+ tcInstDecls1 pcs hst unf_env get_fixity this_mod
+ local_tycons decls `thenTc` \ (pcs_with_insts, inst_env, inst_info, deriv_binds) ->
+ tcSetInstEnv inst_env $
+
+ -- Default declarations
+ tcDefaults decls `thenTc` \ defaulting_tys ->
+ tcSetDefaultTys defaulting_tys $
+
-- Interface type signatures
-
-- We tie a knot so that the Ids read out of interfaces are in scope
-- when we read their pragmas.
-- What we rely on is that pragmas are typechecked lazily; if
- -- any type errors are found (ie there's an inconsistency)
+ -- any type errors are found (ie there's an inconsistency)
-- we silently discard the pragma
+ -- We must do this before mkImplicitDataBinds (which comes next), since
+ -- the latter looks up unpackCStringId, for example, which is usually
+ -- imported
+ tcInterfaceSigs unf_env decls `thenTc` \ sig_ids ->
+ tcExtendGlobalValEnv sig_ids $
+
+ -- Create any necessary record selector Ids and their bindings
+ -- "Necessary" includes data and newtype declarations
+ -- We don't create bindings for dictionary constructors;
+ -- they are always fully applied, and the bindings are just there
+ -- to support partial applications
+ mkImplicitDataBinds tycons `thenTc` \ (data_ids, imp_data_binds) ->
+ mkImplicitClassBinds classes `thenNF_Tc` \ (cls_ids, imp_cls_binds) ->
+
+ -- Extend the global value environment with
+ -- (a) constructors
+ -- (b) record selectors
+ -- (c) class op selectors
+ -- (d) default-method ids... where? I can't see where these are
+ -- put into the envt, and I'm worried that the zonking phase
+ -- will find they aren't there and complain.
+ tcExtendGlobalValEnv data_ids $
+ tcExtendGlobalValEnv cls_ids $
+
+ -- Foreign import declarations next
+ tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) ->
+ tcExtendGlobalValEnv fo_ids $
+
+ -- Value declarations next.
+ -- We also typecheck any extra binds that came out of the "deriving" process
+ tcTopBinds (get_binds decls `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) ->
+ tcSetEnv env $
+
+ -- Foreign export declarations next
+ tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
+
+ -- Second pass over class and instance declarations,
+ -- to compile the bindings themselves.
+ tcInstDecls2 inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
+ tcClassDecls2 decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) ->
+ tcRules decls `thenNF_Tc` \ (lie_rules, rules) ->
+
+ -- Deal with constant or ambiguous InstIds. How could
+ -- there be ambiguous ones? They can only arise if a
+ -- top-level decl falls under the monomorphism
+ -- restriction, and no subsequent decl instantiates its
+ -- type. (Usually, ambiguous type variables are resolved
+ -- during the generalisation step.)
+ let
+ lie_alldecls = lie_valdecls `plusLIE`
+ lie_instdecls `plusLIE`
+ lie_clasdecls `plusLIE`
+ lie_fodecls `plusLIE`
+ lie_rules
+ in
+ tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
+
+ -- Check that Main defines main
+ checkMain this_mod `thenTc_`
+
+ -- Backsubstitution. This must be done last.
+ -- Even tcSimplifyTop may do some unification.
+ let
+ all_binds = imp_data_binds `AndMonoBinds`
+ imp_cls_binds `AndMonoBinds`
+ val_binds `AndMonoBinds`
+ inst_binds `AndMonoBinds`
+ cls_dm_binds `AndMonoBinds`
+ const_inst_binds `AndMonoBinds`
+ foe_binds
+ in
+ zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) ->
+ tcSetEnv final_env $
+ -- zonkTopBinds puts all the top-level Ids into the tcGEnv
+ zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' ->
+ zonkRules rules `thenNF_Tc` \ rules' ->
+
+
+ let groups :: FiniteMap Module TypeEnv
+ groups = groupTyThings (nameEnvElts (getTcGEnv final_env))
+
+ local_type_env :: TypeEnv
+ local_type_env = lookupWithDefaultFM groups emptyNameEnv this_mod
+
+ new_pst :: PackageSymbolTable
+ new_pst = extendTypeEnv (pcs_PST pcs) (delFromFM groups this_mod)
+
+ final_pcs :: PersistentCompilerState
+ final_pcs = pcs_with_insts {pcs_PST = new_pst}
+ in
+ returnTc (final_env, -- WAS: really_final_env,
+ TcResults { tc_pcs = final_pcs,
+ tc_env = local_type_env,
+ tc_binds = all_binds',
+ tc_insts = map iDFunId inst_info,
+ tc_fords = foi_decls ++ foe_decls',
+ tc_rules = rules'
+ })
+
+get_binds decls = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
+\end{code}
- babyTcMtoTcM (tcInterfaceSigs e3 sigs) `thenTc` \ gve_sigs ->
-
- returnTc (gve_sigs, e3, ce_here, tce_here, class_info, tycon_specs, defaulting_tys,
- full_inst_info, extra_deriv_binds, ddump_deriv)
-
- -- End of extremely outer fixTc
- ))) `thenTc` \ (_, e3, ce_here, tce_here, class_info, tycon_specs, defaulting_tys,
- full_inst_info, extra_deriv_binds, ddump_deriv) ->
-
- setDefaultingTys defaulting_tys ( -- to the end...
-
- -- Value declarations next.
- -- We also typecheck any extra binds that came out of the "deriving" process
- -- Nota bene
- tcTopBindsAndThen
- e3
- (\ binds1 (binds2, thing) -> (binds1 `ThenBinds` binds2, thing))
- (valdecls `ThenBinds` extra_deriv_binds)
- (\ e4 ->
- -- Second pass over instance declarations,
- -- to compile the bindings themselves.
- tcInstDecls2 e4 full_inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
- tcClassDecls2 e4 class_info `thenNF_Tc` \ (lie_clasdecls, class_binds) ->
- returnTc ( (EmptyBinds, (inst_binds, class_binds, e4)),
- lie_instdecls `plusLIE` lie_clasdecls,
- () )
- )
-
- `thenTc` \ ((val_binds, (inst_binds, class_binds, e4)), lie_alldecls, _) ->
-
- -- Deal with constant or ambiguous InstIds. How could
- -- there be ambiguous ones? They can only arise if a
- -- top-level decl falls under the monomorphism
- -- restriction, and no subsequent decl instantiates its
- -- type. (Usually, ambiguous type variables are resolved
- -- during the generalisation step.)
-
- tcSimplifyTop (unMkLIE lie_alldecls) `thenTc` \ const_inst_binds ->
-
- -- Backsubstitution. Monomorphic top-level decls may have
- -- been instantiated by subsequent decls, and the final
- -- simplification step may have instantiated some
- -- ambiguous types. So, sadly, we need to back-substitute
- -- over the whole bunch of bindings.
-
- applyTcSubstToBinds val_binds `thenNF_Tc` \ val_binds' ->
- applyTcSubstToBinds inst_binds `thenNF_Tc` \ inst_binds' ->
- applyTcSubstToBinds class_binds `thenNF_Tc` \ class_binds' ->
-
- -- ToDo: probably need to back-substitute over all
- -- stuff in 'e4'; we do so here over the Ids,
- -- which is probably enough. WDP 95/06
- mapNF_Tc applyTcSubstToId (getE_GlobalVals e4)
- `thenNF_Tc` \ if_global_ids ->
-
- -- FINISHED AT LAST
- returnTc (
- (class_binds', inst_binds', val_binds', const_inst_binds),
- -- the next collection is just for mkInterface
- (fixities, if_global_ids, ce_here, tce_here, full_inst_info),
+\begin{code}
+checkMain :: Module -> TcM ()
+checkMain this_mod
+ | moduleName this_mod == mAIN_Name
+ = tcLookupGlobal_maybe mainName `thenNF_Tc` \ maybe_main ->
+ case maybe_main of
+ Just (AnId _) -> returnTc ()
+ other -> addErrTc noMainErr
+
+ | otherwise = returnTc ()
+
+noMainErr
+ = hsep [ptext SLIT("Module"), quotes (ppr mAIN_Name),
+ ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))]
+\end{code}
- tycon_specs,
---UNUSED: e4,
+%************************************************************************
+%* *
+\subsection{Dumping output}
+%* *
+%************************************************************************
- -- and... TCE needed for code generation; rest needed for interpreter.
- -- ToDo: still wrong: needs isLocallyDeclared run over everything
- mkE tce_here {-gve_here lve-} ce_here,
- -- NB: interpreter would probably need the gve_here stuff
- ddump_deriv
- )))
+\begin{code}
+printTcDump dflags Nothing = return ()
+printTcDump dflags (Just (_,results))
+ = do dumpIfSet_dyn dflags Opt_D_dump_types
+ "Type signatures" (dump_sigs results)
+ dumpIfSet_dyn dflags Opt_D_dump_tc
+ "Typechecked" (dump_tc results)
+
+dump_tc results
+ = vcat [ppr (tc_binds results),
+ pp_rules (tc_rules results) --,
+-- ppr_gen_tycons (tc_tycons results)
+ ]
+
+dump_sigs results -- Print type signatures
+ = -- Convert to HsType so that we get source-language style printing
+ -- And sort by RdrName
+ vcat $ map ppr_sig $ sortLt lt_sig $
+ [(toRdrName id, toHsType (idType id))
+ | AnId id <- nameEnvElts (tc_env results),
+ want_sig id
+ ]
+ where
+ lt_sig (n1,_) (n2,_) = n1 < n2
+ ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t
+
+ want_sig id | opt_PprStyle_Debug = True
+ | otherwise = isLocallyDefined n &&
+ isGlobalName n &&
+ not (isSysOcc (nameOccName n))
+ where
+ n = idName id
+
+ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"),
+ vcat (map ppr_gen_tycon (filter isLocallyDefined tcs)),
+ ptext SLIT("#-}")
+ ]
+
+-- x&y are now Id's, not CoreExpr's
+ppr_gen_tycon tycon
+ | Just ep <- tyConGenInfo tycon
+ = (ppr tycon <> colon) $$ nest 4 (ppr_ep ep)
+
+ | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable")
+
+ppr_ep (EP from to)
+ = vcat [ ptext SLIT("Rep type:") <+> ppr (funResultTy from_tau),
+ ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)),
+ ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to))
+ ]
+ where
+ (_,from_tau) = splitForAllTys (idType from)
+
+pp_rules [] = empty
+pp_rules rs = vcat [ptext SLIT("{-# RULES"),
+ nest 4 (vcat (map ppr rs)),
+ ptext SLIT("#-}")]
\end{code}
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