X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Fprelude%2FTysWiredIn.lhs;h=c8ffc3b9a090790eb338bc8a865f7171dfa4662d;hb=f714e6b642fd614a9971717045ae47c3d871275e;hp=daa9d1950abc4cf4d4e5595af7d7fa4be70352c7;hpb=51f8f0f50c1a709ed898d149f458f781279fa4c6;p=ghc-hetmet.git diff --git a/ghc/compiler/prelude/TysWiredIn.lhs b/ghc/compiler/prelude/TysWiredIn.lhs index daa9d19..c8ffc3b 100644 --- a/ghc/compiler/prelude/TysWiredIn.lhs +++ b/ghc/compiler/prelude/TysWiredIn.lhs @@ -11,71 +11,46 @@ types and operations.'' \begin{code} module TysWiredIn ( - wiredInTyCons, genericTyCons, - - addrDataCon, - addrTy, - addrTyCon, - ptrDataCon, - ptrTy, - ptrTyCon, - funPtrDataCon, - funPtrTy, - funPtrTyCon, - boolTy, - boolTyCon, - charDataCon, - charTy, - charTyCon, - consDataCon, - doubleDataCon, - doubleTy, - doubleTyCon, - falseDataCon, falseDataConId, - floatDataCon, - floatTy, - floatTyCon, - - intDataCon, - intTy, - intTyCon, + wiredInTyCons, + + boolTy, boolTyCon, boolTyCon_RDR, boolTyConName, + trueDataCon, trueDataConId, true_RDR, + falseDataCon, falseDataConId, false_RDR, - integerTy, - integerTyCon, - smallIntegerDataCon, - largeIntegerDataCon, + charTyCon, charDataCon, charTyCon_RDR, + charTy, stringTy, charTyConName, - listTyCon, + + doubleTyCon, doubleDataCon, doubleTy, + + floatTyCon, floatDataCon, floatTy, + intTyCon, intDataCon, intTyCon_RDR, intDataCon_RDR, intTyConName, + intTy, + + listTyCon, nilDataCon, consDataCon, + listTyCon_RDR, consDataCon_RDR, listTyConName, mkListTy, - nilDataCon, -- tuples mkTupleTy, tupleTyCon, tupleCon, - unitTyCon, unitDataConId, pairTyCon, + unitTyCon, unitDataCon, unitDataConId, pairTyCon, unboxedSingletonTyCon, unboxedSingletonDataCon, unboxedPairTyCon, unboxedPairDataCon, - -- Generics - genUnitTyCon, genUnitDataCon, - plusTyCon, inrDataCon, inlDataCon, - crossTyCon, crossDataCon, - - stablePtrTyCon, - stringTy, - trueDataCon, trueDataConId, unitTy, voidTy, - wordDataCon, - wordTy, - wordTyCon + + -- parallel arrays + mkPArrTy, + parrTyCon, parrFakeCon, isPArrTyCon, isPArrFakeCon, + parrTyCon_RDR, parrTyConName ) where #include "HsVersions.h" -import {-# SOURCE #-} MkId( mkDataConId, mkDataConWrapId ) -import {-# SOURCE #-} Generics( mkTyConGenInfo ) +import {-# SOURCE #-} MkId( mkDataConIds ) -- friends: import PrelNames @@ -83,29 +58,31 @@ import TysPrim -- others: import Constants ( mAX_TUPLE_SIZE ) -import Module ( mkPrelModule ) -import Name ( Name, nameRdrName, nameUnique, nameOccName, +import Module ( Module ) +import RdrName ( nameRdrName ) +import Name ( Name, nameUnique, nameOccName, nameModule, mkWiredInName ) -import OccName ( mkOccFS, tcName, dataName, mkWorkerOcc, mkGenOcc1, mkGenOcc2 ) -import RdrName ( rdrNameOcc ) -import DataCon ( DataCon, mkDataCon, dataConId ) +import OccName ( mkOccFS, tcName, dataName, mkTupleOcc, mkDataConWorkerOcc ) +import DataCon ( DataCon, mkDataCon, dataConWorkId, dataConSourceArity ) import Var ( TyVar, tyVarKind ) -import TyCon ( TyCon, AlgTyConFlavour(..), tyConDataCons, - mkTupleTyCon, mkAlgTyCon +import TyCon ( TyCon, AlgTyConFlavour(..), DataConDetails(..), tyConDataCons, + mkTupleTyCon, mkAlgTyCon, tyConName ) import BasicTypes ( Arity, RecFlag(..), Boxity(..), isBoxed, StrictnessMark(..) ) -import Type ( Type, mkTyConTy, mkTyConApp, mkTyVarTys, - mkArrowKinds, liftedTypeKind, unliftedTypeKind, - TauType, ThetaType ) -import Unique ( incrUnique, mkTupleTyConUnique, mkTupleDataConUnique ) +import Type ( Type, mkTyConTy, mkTyConApp, mkTyVarTy, mkTyVarTys, + ThetaType, TyThing(..) ) +import Kind ( mkArrowKinds, liftedTypeKind, ubxTupleKind ) +import Unique ( incrUnique, mkTupleTyConUnique, + mkTupleDataConUnique, mkPArrDataConUnique ) import PrelNames import Array +import FastString +import Outputable -alpha_tyvar = [alphaTyVar] -alpha_ty = [alphaTy] -alpha_beta_tyvars = [alphaTyVar, betaTyVar] +alpha_tyvar = [alphaTyVar] +alpha_ty = [alphaTy] \end{code} @@ -115,30 +92,69 @@ alpha_beta_tyvars = [alphaTyVar, betaTyVar] %* * %************************************************************************ +If you change which things are wired in, make sure you change their +names in PrelNames, so they use wTcQual, wDataQual, etc + \begin{code} -wiredInTyCons :: [TyCon] -wiredInTyCons = data_tycons ++ tuple_tycons ++ unboxed_tuple_tycons - -data_tycons = genericTyCons ++ - [ addrTyCon - , ptrTyCon - , funPtrTyCon - , boolTyCon +wiredInTyCons :: [TyCon] -- Excludes tuples +wiredInTyCons = [ unitTyCon -- Not treated like other tuples, because + -- it's defined in GHC.Base, and there's only + -- one of it. We put it in wiredInTyCons so + -- that it'll pre-populate the name cache, so + -- the special case in lookupOrigNameCache + -- doesn't need to look out for it + , boolTyCon , charTyCon , doubleTyCon , floatTyCon , intTyCon - , integerTyCon , listTyCon - , wordTyCon + , parrTyCon ] +\end{code} -genericTyCons :: [TyCon] -genericTyCons = [ plusTyCon, crossTyCon, genUnitTyCon ] - - -tuple_tycons = unitTyCon : [tupleTyCon Boxed i | i <- [2..mAX_TUPLE_SIZE] ] -unboxed_tuple_tycons = [tupleTyCon Unboxed i | i <- [1..mAX_TUPLE_SIZE] ] +\begin{code} +mkWiredInTyConName :: Module -> FastString -> Unique -> TyCon -> Name +mkWiredInTyConName mod fs uniq tycon + = mkWiredInName mod (mkOccFS tcName fs) uniq + Nothing -- No parent object + (ATyCon tycon) -- Relevant TyCon + +mkWiredInDataConName :: Module -> FastString -> Unique -> DataCon -> Name -> Name +mkWiredInDataConName mod fs uniq datacon parent + = mkWiredInName mod (mkOccFS dataName fs) uniq + (Just parent) -- Name of parent TyCon + (ADataCon datacon) -- Relevant DataCon + +charTyConName = mkWiredInTyConName pREL_BASE FSLIT("Char") charTyConKey charTyCon +charDataConName = mkWiredInDataConName pREL_BASE FSLIT("C#") charDataConKey charDataCon charTyConName +intTyConName = mkWiredInTyConName pREL_BASE FSLIT("Int") intTyConKey intTyCon +intDataConName = mkWiredInDataConName pREL_BASE FSLIT("I#") intDataConKey intDataCon intTyConName + +boolTyConName = mkWiredInTyConName pREL_BASE FSLIT("Bool") boolTyConKey boolTyCon +falseDataConName = mkWiredInDataConName pREL_BASE FSLIT("False") falseDataConKey falseDataCon boolTyConName +trueDataConName = mkWiredInDataConName pREL_BASE FSLIT("True") trueDataConKey trueDataCon boolTyConName +listTyConName = mkWiredInTyConName pREL_BASE FSLIT("[]") listTyConKey listTyCon +nilDataConName = mkWiredInDataConName pREL_BASE FSLIT("[]") nilDataConKey nilDataCon listTyConName +consDataConName = mkWiredInDataConName pREL_BASE FSLIT(":") consDataConKey consDataCon listTyConName + +floatTyConName = mkWiredInTyConName pREL_FLOAT FSLIT("Float") floatTyConKey floatTyCon +floatDataConName = mkWiredInDataConName pREL_FLOAT FSLIT("F#") floatDataConKey floatDataCon floatTyConName +doubleTyConName = mkWiredInTyConName pREL_FLOAT FSLIT("Double") doubleTyConKey doubleTyCon +doubleDataConName = mkWiredInDataConName pREL_FLOAT FSLIT("D#") doubleDataConKey doubleDataCon doubleTyConName + +parrTyConName = mkWiredInTyConName pREL_PARR FSLIT("[::]") parrTyConKey parrTyCon +parrDataConName = mkWiredInDataConName pREL_PARR FSLIT("PArr") parrDataConKey parrDataCon parrTyConName + +boolTyCon_RDR = nameRdrName boolTyConName +false_RDR = nameRdrName falseDataConName +true_RDR = nameRdrName trueDataConName +intTyCon_RDR = nameRdrName intTyConName +charTyCon_RDR = nameRdrName charTyConName +intDataCon_RDR = nameRdrName intDataConName +listTyCon_RDR = nameRdrName listTyConName +consDataCon_RDR = nameRdrName consDataConName +parrTyCon_RDR = nameRdrName parrTyConName \end{code} @@ -149,64 +165,48 @@ unboxed_tuple_tycons = [tupleTyCon Unboxed i | i <- [1..mAX_TUPLE_SIZE] ] %************************************************************************ \begin{code} -pcNonRecDataTyCon = pcTyCon DataTyCon NonRecursive -pcRecDataTyCon = pcTyCon DataTyCon Recursive +pcNonRecDataTyCon = pcTyCon False NonRecursive +pcRecDataTyCon = pcTyCon False Recursive -pcTyCon new_or_data is_rec name tyvars argvrcs cons +pcTyCon is_enum is_rec name tyvars argvrcs cons = tycon where - tycon = mkAlgTyCon name kind + tycon = mkAlgTyCon name + (mkArrowKinds (map tyVarKind tyvars) liftedTypeKind) tyvars [] -- No context argvrcs - cons - (length cons) + (DataCons cons) [] -- No record selectors - new_or_data + (DataTyCon is_enum) is_rec - gen_info - - mod = nameModule name - kind = mkArrowKinds (map tyVarKind tyvars) liftedTypeKind - gen_info = mk_tc_gen_info mod (nameUnique name) name tycon + True -- All the wired-in tycons have generics --- We generate names for the generic to/from Ids by incrementing --- the TyCon unique. So each Prelude tycon needs 3 slots, one --- for itself and two more for the generic Ids. -mk_tc_gen_info mod tc_uniq tc_name tycon - = mkTyConGenInfo tycon [name1, name2] - where - tc_occ_name = nameOccName tc_name - occ_name1 = mkGenOcc1 tc_occ_name - occ_name2 = mkGenOcc2 tc_occ_name - fn1_key = incrUnique tc_uniq - fn2_key = incrUnique fn1_key - name1 = mkWiredInName mod occ_name1 fn1_key - name2 = mkWiredInName mod occ_name2 fn2_key - -pcDataCon :: Name -> [TyVar] -> ThetaType -> [TauType] -> TyCon -> DataCon +pcDataCon :: Name -> [TyVar] -> ThetaType -> [Type] -> TyCon -> DataCon +-- The Name should be in the DataName name space; it's the name +-- of the DataCon itself. +-- -- The unique is the first of two free uniques; --- the first is used for the datacon itself and the worker; --- the second is used for the wrapper. +-- the first is used for the datacon itself, +-- the second is used for the "worker name" -pcDataCon name tyvars context arg_tys tycon +pcDataCon dc_name tyvars context arg_tys tycon = data_con where - data_con = mkDataCon name - [ NotMarkedStrict | a <- arg_tys ] - [ {- no labelled fields -} ] - tyvars context [] [] arg_tys tycon work_id wrap_id - - wrap_rdr = nameRdrName name - wrap_occ = rdrNameOcc wrap_rdr - - mod = nameModule name - wrap_id = mkDataConWrapId data_con - - work_occ = mkWorkerOcc wrap_occ - work_key = incrUnique (nameUnique name) - work_name = mkWiredInName mod work_occ work_key - work_id = mkDataConId work_name data_con + data_con = mkDataCon dc_name + (map (const NotMarkedStrict) arg_tys) + [{- No labelled fields -}] + tyvars context [] [] arg_tys tycon + (mkDataConIds bogus_wrap_name wrk_name data_con) + + mod = nameModule dc_name + wrk_occ = mkDataConWorkerOcc (nameOccName dc_name) + wrk_key = incrUnique (nameUnique dc_name) + wrk_name = mkWiredInName mod wrk_occ wrk_key + (Just (tyConName tycon)) + (AnId (dataConWorkId data_con)) + bogus_wrap_name = pprPanic "Wired-in data wrapper id" (ppr dc_name) + -- Wired-in types are too simple to need wrappers \end{code} @@ -228,32 +228,35 @@ tupleCon Boxed i = snd (boxedTupleArr ! i) tupleCon Unboxed i = snd (unboxedTupleArr ! i) boxedTupleArr, unboxedTupleArr :: Array Int (TyCon,DataCon) -boxedTupleArr = array (0,mAX_TUPLE_SIZE) [(i,mk_tuple Boxed i) | i <- [0..mAX_TUPLE_SIZE]] -unboxedTupleArr = array (0,mAX_TUPLE_SIZE) [(i,mk_tuple Unboxed i) | i <- [0..mAX_TUPLE_SIZE]] +boxedTupleArr = listArray (0,mAX_TUPLE_SIZE) [mk_tuple Boxed i | i <- [0..mAX_TUPLE_SIZE]] +unboxedTupleArr = listArray (0,mAX_TUPLE_SIZE) [mk_tuple Unboxed i | i <- [0..mAX_TUPLE_SIZE]] mk_tuple :: Boxity -> Int -> (TyCon,DataCon) mk_tuple boxity arity = (tycon, tuple_con) where tycon = mkTupleTyCon tc_name tc_kind arity tyvars tuple_con boxity gen_info - tc_name = mkWiredInName mod (mkOccFS tcName name_str) tc_uniq + mod = mkTupleModule boxity arity + tc_name = mkWiredInName mod (mkTupleOcc tcName boxity arity) tc_uniq + Nothing (ATyCon tycon) tc_kind = mkArrowKinds (map tyVarKind tyvars) res_kind res_kind | isBoxed boxity = liftedTypeKind - | otherwise = unliftedTypeKind + | otherwise = ubxTupleKind tyvars | isBoxed boxity = take arity alphaTyVars | otherwise = take arity openAlphaTyVars - tuple_con = pcDataCon name tyvars [] tyvar_tys tycon + tuple_con = pcDataCon dc_name tyvars [] tyvar_tys tycon tyvar_tys = mkTyVarTys tyvars - (mod_name, name_str) = mkTupNameStr boxity arity - name = mkWiredInName mod (mkOccFS dataName name_str) dc_uniq + dc_name = mkWiredInName mod (mkTupleOcc dataName boxity arity) dc_uniq + (Just tc_name) (ADataCon tuple_con) tc_uniq = mkTupleTyConUnique boxity arity dc_uniq = mkTupleDataConUnique boxity arity - mod = mkPrelModule mod_name - gen_info = mk_tc_gen_info mod tc_uniq tc_name tycon + gen_info = True -- Tuples all have generics.. + -- hmm: that's a *lot* of code unitTyCon = tupleTyCon Boxed 0 -unitDataConId = dataConId (head (tyConDataCons unitTyCon)) +unitDataCon = head (tyConDataCons unitTyCon) +unitDataConId = dataConWorkId unitDataCon pairTyCon = tupleTyCon Boxed 2 @@ -303,34 +306,6 @@ intDataCon = pcDataCon intDataConName [] [] [intPrimTy] intTyCon \end{code} \begin{code} -wordTy = mkTyConTy wordTyCon - -wordTyCon = pcNonRecDataTyCon wordTyConName [] [] [wordDataCon] -wordDataCon = pcDataCon wordDataConName [] [] [wordPrimTy] wordTyCon -\end{code} - -\begin{code} -addrTy = mkTyConTy addrTyCon - -addrTyCon = pcNonRecDataTyCon addrTyConName [] [] [addrDataCon] -addrDataCon = pcDataCon addrDataConName [] [] [addrPrimTy] addrTyCon -\end{code} - -\begin{code} -ptrTy = mkTyConTy ptrTyCon - -ptrTyCon = pcNonRecDataTyCon ptrTyConName alpha_tyvar [(True,False)] [ptrDataCon] -ptrDataCon = pcDataCon ptrDataConName alpha_tyvar [] [addrPrimTy] ptrTyCon -\end{code} - -\begin{code} -funPtrTy = mkTyConTy funPtrTyCon - -funPtrTyCon = pcNonRecDataTyCon funPtrTyConName alpha_tyvar [(True,False)] [funPtrDataCon] -funPtrDataCon = pcDataCon funPtrDataConName alpha_tyvar [] [addrPrimTy] funPtrTyCon -\end{code} - -\begin{code} floatTy = mkTyConTy floatTyCon floatTyCon = pcNonRecDataTyCon floatTyConName [] [] [floatDataCon] @@ -340,60 +315,10 @@ floatDataCon = pcDataCon floatDataConName [] [] [floatPrimTy] floatTyCon \begin{code} doubleTy = mkTyConTy doubleTyCon -doubleTyCon = pcNonRecDataTyCon doubleTyConName [] [] [doubleDataCon] +doubleTyCon = pcNonRecDataTyCon doubleTyConName [] [] [doubleDataCon] doubleDataCon = pcDataCon doubleDataConName [] [] [doublePrimTy] doubleTyCon \end{code} -\begin{code} -stablePtrTyCon - = pcNonRecDataTyCon stablePtrTyConName - alpha_tyvar [(True,False)] [stablePtrDataCon] - where - stablePtrDataCon - = pcDataCon stablePtrDataConName - alpha_tyvar [] [mkStablePtrPrimTy alphaTy] stablePtrTyCon -\end{code} - -\begin{code} -foreignObjTyCon - = pcNonRecDataTyCon foreignObjTyConName - [] [] [foreignObjDataCon] - where - foreignObjDataCon - = pcDataCon foreignObjDataConName - [] [] [foreignObjPrimTy] foreignObjTyCon -\end{code} - -\begin{code} -foreignPtrTyCon - = pcNonRecDataTyCon foreignPtrTyConName - alpha_tyvar [(True,False)] [foreignPtrDataCon] - where - foreignPtrDataCon - = pcDataCon foreignPtrDataConName - alpha_tyvar [] [foreignObjPrimTy] foreignPtrTyCon -\end{code} - -%************************************************************************ -%* * -\subsection[TysWiredIn-Integer]{@Integer@ and its related ``pairing'' types} -%* * -%************************************************************************ - -@Integer@ and its pals are not really primitive. @Integer@ itself, first: -\begin{code} -integerTy :: Type -integerTy = mkTyConTy integerTyCon - -integerTyCon = pcNonRecDataTyCon integerTyConName - [] [] [smallIntegerDataCon, largeIntegerDataCon] - -smallIntegerDataCon = pcDataCon smallIntegerDataConName - [] [] [intPrimTy] integerTyCon -largeIntegerDataCon = pcDataCon largeIntegerDataConName - [] [] [intPrimTy, byteArrayPrimTy] integerTyCon -\end{code} - %************************************************************************ %* * @@ -446,14 +371,14 @@ primitive counterpart. \begin{code} boolTy = mkTyConTy boolTyCon -boolTyCon = pcTyCon EnumTyCon NonRecursive boolTyConName +boolTyCon = pcTyCon True NonRecursive boolTyConName [] [] [falseDataCon, trueDataCon] falseDataCon = pcDataCon falseDataConName [] [] [] boolTyCon trueDataCon = pcDataCon trueDataConName [] [] [] boolTyCon -falseDataConId = dataConId falseDataCon -trueDataConId = dataConId trueDataCon +falseDataConId = dataConWorkId falseDataCon +trueDataConId = dataConWorkId trueDataCon \end{code} %************************************************************************ @@ -540,36 +465,80 @@ unitTy = mkTupleTy Boxed 0 [] \end{code} %************************************************************************ -%* * -\subsection{Wired In Type Constructors for Representation Types} -%* * +%* * +\subsection[TysWiredIn-PArr]{The @[::]@ type} +%* * %************************************************************************ -The following code defines the wired in datatypes cross, plus, unit -and c_of needed for the generic methods. - -Ok, so the basic story is that for each type constructor I need to -create 2 things - a TyCon and a DataCon and then we are basically -ok. There are going to be no arguments passed to these functions -because -well- there is nothing to pass to these functions. +Special syntax for parallel arrays needs some wired in definitions. \begin{code} -crossTyCon :: TyCon -crossTyCon = pcNonRecDataTyCon crossTyConName alpha_beta_tyvars [] [crossDataCon] - -crossDataCon :: DataCon -crossDataCon = pcDataCon crossDataConName alpha_beta_tyvars [] [alphaTy, betaTy] crossTyCon +-- construct a type representing the application of the parallel array +-- constructor +-- +mkPArrTy :: Type -> Type +mkPArrTy ty = mkTyConApp parrTyCon [ty] -plusTyCon :: TyCon -plusTyCon = pcNonRecDataTyCon plusTyConName alpha_beta_tyvars [] [inlDataCon, inrDataCon] +-- represents the type constructor of parallel arrays +-- +-- * this must match the definition in `PrelPArr' +-- +-- NB: Although the constructor is given here, it will not be accessible in +-- user code as it is not in the environment of any compiled module except +-- `PrelPArr'. +-- +parrTyCon :: TyCon +parrTyCon = pcNonRecDataTyCon parrTyConName alpha_tyvar [(True, False)] [parrDataCon] + +parrDataCon :: DataCon +parrDataCon = pcDataCon + parrDataConName + alpha_tyvar -- forall'ed type variables + [] -- context + [intPrimTy, -- 1st argument: Int# + mkTyConApp -- 2nd argument: Array# a + arrayPrimTyCon + alpha_ty] + parrTyCon + +-- check whether a type constructor is the constructor for parallel arrays +-- +isPArrTyCon :: TyCon -> Bool +isPArrTyCon tc = tyConName tc == parrTyConName -inlDataCon, inrDataCon :: DataCon -inlDataCon = pcDataCon inlDataConName alpha_beta_tyvars [] [alphaTy] plusTyCon -inrDataCon = pcDataCon inrDataConName alpha_beta_tyvars [] [betaTy] plusTyCon +-- fake array constructors +-- +-- * these constructors are never really used to represent array values; +-- however, they are very convenient during desugaring (and, in particular, +-- in the pattern matching compiler) to treat array pattern just like +-- yet another constructor pattern +-- +parrFakeCon :: Arity -> DataCon +parrFakeCon i | i > mAX_TUPLE_SIZE = mkPArrFakeCon i -- build one specially +parrFakeCon i = parrFakeConArr!i -genUnitTyCon :: TyCon -- The "1" type constructor for generics -genUnitTyCon = pcNonRecDataTyCon genUnitTyConName [] [] [genUnitDataCon] +-- pre-defined set of constructors +-- +parrFakeConArr :: Array Int DataCon +parrFakeConArr = array (0, mAX_TUPLE_SIZE) [(i, mkPArrFakeCon i) + | i <- [0..mAX_TUPLE_SIZE]] -genUnitDataCon :: DataCon -genUnitDataCon = pcDataCon genUnitDataConName [] [] [] genUnitTyCon +-- build a fake parallel array constructor for the given arity +-- +mkPArrFakeCon :: Int -> DataCon +mkPArrFakeCon arity = data_con + where + data_con = pcDataCon name [tyvar] [] tyvarTys parrTyCon + tyvar = head alphaTyVars + tyvarTys = replicate arity $ mkTyVarTy tyvar + nameStr = mkFastString ("MkPArr" ++ show arity) + name = mkWiredInName pREL_PARR (mkOccFS dataName nameStr) uniq + Nothing (ADataCon data_con) + uniq = mkPArrDataConUnique arity + +-- checks whether a data constructor is a fake constructor for parallel arrays +-- +isPArrFakeCon :: DataCon -> Bool +isPArrFakeCon dcon = dcon == parrFakeCon (dataConSourceArity dcon) \end{code} +