% % (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[Id]{@Ids@: Value and constructor identifiers} \begin{code} {-# OPTIONS -fno-warn-tabs #-} -- The above warning supression flag is a temporary kludge. -- While working on this module you are encouraged to remove it and -- detab the module (please do the detabbing in a separate patch). See -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces -- for details -- | -- #name_types# -- GHC uses several kinds of name internally: -- -- * 'OccName.OccName': see "OccName#name_types" -- -- * 'RdrName.RdrName': see "RdrName#name_types" -- -- * 'Name.Name': see "Name#name_types" -- -- * 'Id.Id' represents names that not only have a 'Name.Name' but also a 'TypeRep.Type' and some additional -- details (a 'IdInfo.IdInfo' and one of 'Var.LocalIdDetails' or 'IdInfo.GlobalIdDetails') that -- are added, modified and inspected by various compiler passes. These 'Var.Var' names may either -- be global or local, see "Var#globalvslocal" -- -- * 'Var.Var': see "Var#name_types" module Id ( -- * The main types Var, Id, isId, -- ** Simple construction mkGlobalId, mkVanillaGlobal, mkVanillaGlobalWithInfo, mkLocalId, mkLocalIdWithInfo, mkExportedLocalId, mkSysLocal, mkSysLocalM, mkUserLocal, mkUserLocalM, mkTemplateLocals, mkTemplateLocalsNum, mkTemplateLocal, mkWorkerId, mkWiredInIdName, -- ** Taking an Id apart idName, idType, idUnique, idInfo, idDetails, idPrimRep, recordSelectorFieldLabel, -- ** Modifying an Id setIdName, setIdUnique, Id.setIdType, setIdExported, setIdNotExported, globaliseId, localiseId, setIdInfo, lazySetIdInfo, modifyIdInfo, maybeModifyIdInfo, zapLamIdInfo, zapDemandIdInfo, zapFragileIdInfo, transferPolyIdInfo, -- ** Predicates on Ids isImplicitId, isDeadBinder, isStrictId, isExportedId, isLocalId, isGlobalId, isRecordSelector, isNaughtyRecordSelector, isClassOpId_maybe, isDFunId, isPrimOpId, isPrimOpId_maybe, isFCallId, isFCallId_maybe, isDataConWorkId, isDataConWorkId_maybe, isDataConId_maybe, idDataCon, isConLikeId, isBottomingId, idIsFrom, hasNoBinding, -- ** Evidence variables DictId, isDictId, isEvVar, -- ** Inline pragma stuff idInlinePragma, setInlinePragma, modifyInlinePragma, idInlineActivation, setInlineActivation, idRuleMatchInfo, -- ** One-shot lambdas isOneShotBndr, isOneShotLambda, isStateHackType, setOneShotLambda, clearOneShotLambda, -- ** Reading 'IdInfo' fields idArity, idDemandInfo, idDemandInfo_maybe, idStrictness, idStrictness_maybe, idUnfolding, realIdUnfolding, idSpecialisation, idCoreRules, idHasRules, idCafInfo, idLBVarInfo, idOccInfo, -- ** Writing 'IdInfo' fields setIdUnfoldingLazily, setIdUnfolding, setIdArity, setIdDemandInfo, setIdStrictness, zapIdStrictness, setIdSpecialisation, setIdCafInfo, setIdOccInfo, zapIdOccInfo, ) where #include "HsVersions.h" import CoreSyn ( CoreRule, Unfolding( NoUnfolding ) ) import IdInfo import BasicTypes -- Imported and re-exported import Var( Var, Id, DictId, idInfo, idDetails, globaliseId, varType, isId, isLocalId, isGlobalId, isExportedId ) import qualified Var import TyCon import Type import TysPrim import DataCon import Demand import Name import Module import Class import PrimOp import ForeignCall import Maybes import SrcLoc import Outputable import Unique import UniqSupply import FastString import Util( count ) import StaticFlags -- infixl so you can say (id `set` a `set` b) infixl 1 `setIdUnfoldingLazily`, `setIdUnfolding`, `setIdArity`, `setIdOccInfo`, `setIdDemandInfo`, `setIdStrictness`, `setIdSpecialisation`, `setInlinePragma`, `setInlineActivation`, `idCafInfo` \end{code} %************************************************************************ %* * \subsection{Basic Id manipulation} %* * %************************************************************************ \begin{code} idName :: Id -> Name idName = Var.varName idUnique :: Id -> Unique idUnique = Var.varUnique idType :: Id -> Kind idType = Var.varType idPrimRep :: Id -> PrimRep idPrimRep id = typePrimRep (idType id) setIdName :: Id -> Name -> Id setIdName = Var.setVarName setIdUnique :: Id -> Unique -> Id setIdUnique = Var.setVarUnique -- | Not only does this set the 'Id' 'Type', it also evaluates the type to try and -- reduce space usage setIdType :: Id -> Type -> Id setIdType id ty = seqType ty `seq` Var.setVarType id ty setIdExported :: Id -> Id setIdExported = Var.setIdExported setIdNotExported :: Id -> Id setIdNotExported = Var.setIdNotExported localiseId :: Id -> Id -- Make an with the same unique and type as the -- incoming Id, but with an *Internal* Name and *LocalId* flavour localiseId id | ASSERT( isId id ) isLocalId id && isInternalName name = id | otherwise = mkLocalIdWithInfo (localiseName name) (idType id) (idInfo id) where name = idName id lazySetIdInfo :: Id -> IdInfo -> Id lazySetIdInfo = Var.lazySetIdInfo setIdInfo :: Id -> IdInfo -> Id setIdInfo id info = seqIdInfo info `seq` (lazySetIdInfo id info) -- Try to avoid spack leaks by seq'ing modifyIdInfo :: (IdInfo -> IdInfo) -> Id -> Id modifyIdInfo fn id = setIdInfo id (fn (idInfo id)) -- maybeModifyIdInfo tries to avoid unnecesary thrashing maybeModifyIdInfo :: Maybe IdInfo -> Id -> Id maybeModifyIdInfo (Just new_info) id = lazySetIdInfo id new_info maybeModifyIdInfo Nothing id = id \end{code} %************************************************************************ %* * \subsection{Simple Id construction} %* * %************************************************************************ Absolutely all Ids are made by mkId. It is just like Var.mkId, but in addition it pins free-tyvar-info onto the Id's type, where it can easily be found. Note [Free type variables] ~~~~~~~~~~~~~~~~~~~~~~~~~~ At one time we cached the free type variables of the type of an Id at the root of the type in a TyNote. The idea was to avoid repeating the free-type-variable calculation. But it turned out to slow down the compiler overall. I don't quite know why; perhaps finding free type variables of an Id isn't all that common whereas applying a substitution (which changes the free type variables) is more common. Anyway, we removed it in March 2008. \begin{code} -- | For an explanation of global vs. local 'Id's, see "Var#globalvslocal" mkGlobalId :: IdDetails -> Name -> Type -> IdInfo -> Id mkGlobalId = Var.mkGlobalVar -- | Make a global 'Id' without any extra information at all mkVanillaGlobal :: Name -> Type -> Id mkVanillaGlobal name ty = mkVanillaGlobalWithInfo name ty vanillaIdInfo -- | Make a global 'Id' with no global information but some generic 'IdInfo' mkVanillaGlobalWithInfo :: Name -> Type -> IdInfo -> Id mkVanillaGlobalWithInfo = mkGlobalId VanillaId -- | For an explanation of global vs. local 'Id's, see "Var#globalvslocal" mkLocalId :: Name -> Type -> Id mkLocalId name ty = mkLocalIdWithInfo name ty vanillaIdInfo mkLocalIdWithInfo :: Name -> Type -> IdInfo -> Id mkLocalIdWithInfo name ty info = Var.mkLocalVar VanillaId name ty info -- Note [Free type variables] -- | Create a local 'Id' that is marked as exported. -- This prevents things attached to it from being removed as dead code. mkExportedLocalId :: Name -> Type -> Id mkExportedLocalId name ty = Var.mkExportedLocalVar VanillaId name ty vanillaIdInfo -- Note [Free type variables] -- | Create a system local 'Id'. These are local 'Id's (see "Var#globalvslocal") -- that are created by the compiler out of thin air mkSysLocal :: FastString -> Unique -> Type -> Id mkSysLocal fs uniq ty = mkLocalId (mkSystemVarName uniq fs) ty mkSysLocalM :: MonadUnique m => FastString -> Type -> m Id mkSysLocalM fs ty = getUniqueM >>= (\uniq -> return (mkSysLocal fs uniq ty)) -- | Create a user local 'Id'. These are local 'Id's (see "Var#globalvslocal") with a name and location that the user might recognize mkUserLocal :: OccName -> Unique -> Type -> SrcSpan -> Id mkUserLocal occ uniq ty loc = mkLocalId (mkInternalName uniq occ loc) ty mkUserLocalM :: MonadUnique m => OccName -> Type -> SrcSpan -> m Id mkUserLocalM occ ty loc = getUniqueM >>= (\uniq -> return (mkUserLocal occ uniq ty loc)) mkWiredInIdName :: Module -> FastString -> Unique -> Id -> Name mkWiredInIdName mod fs uniq id = mkWiredInName mod (mkOccNameFS varName fs) uniq (AnId id) UserSyntax \end{code} Make some local @Ids@ for a template @CoreExpr@. These have bogus @Uniques@, but that's OK because the templates are supposed to be instantiated before use. \begin{code} -- | Workers get local names. "CoreTidy" will externalise these if necessary mkWorkerId :: Unique -> Id -> Type -> Id mkWorkerId uniq unwrkr ty = mkLocalId (mkDerivedInternalName mkWorkerOcc uniq (getName unwrkr)) ty -- | Create a /template local/: a family of system local 'Id's in bijection with @Int@s, typically used in unfoldings mkTemplateLocal :: Int -> Type -> Id mkTemplateLocal i ty = mkSysLocal (fsLit "tpl") (mkBuiltinUnique i) ty -- | Create a template local for a series of types mkTemplateLocals :: [Type] -> [Id] mkTemplateLocals = mkTemplateLocalsNum 1 -- | Create a template local for a series of type, but start from a specified template local mkTemplateLocalsNum :: Int -> [Type] -> [Id] mkTemplateLocalsNum n tys = zipWith mkTemplateLocal [n..] tys \end{code} %************************************************************************ %* * \subsection{Special Ids} %* * %************************************************************************ \begin{code} -- | If the 'Id' is that for a record selector, extract the 'sel_tycon' and label. Panic otherwise recordSelectorFieldLabel :: Id -> (TyCon, FieldLabel) recordSelectorFieldLabel id = case Var.idDetails id of RecSelId { sel_tycon = tycon } -> (tycon, idName id) _ -> panic "recordSelectorFieldLabel" isRecordSelector :: Id -> Bool isNaughtyRecordSelector :: Id -> Bool isPrimOpId :: Id -> Bool isFCallId :: Id -> Bool isDataConWorkId :: Id -> Bool isDFunId :: Id -> Bool isClassOpId_maybe :: Id -> Maybe Class isPrimOpId_maybe :: Id -> Maybe PrimOp isFCallId_maybe :: Id -> Maybe ForeignCall isDataConWorkId_maybe :: Id -> Maybe DataCon isRecordSelector id = case Var.idDetails id of RecSelId {} -> True _ -> False isNaughtyRecordSelector id = case Var.idDetails id of RecSelId { sel_naughty = n } -> n _ -> False isClassOpId_maybe id = case Var.idDetails id of ClassOpId cls -> Just cls _other -> Nothing isPrimOpId id = case Var.idDetails id of PrimOpId _ -> True _ -> False isDFunId id = case Var.idDetails id of DFunId {} -> True _ -> False isPrimOpId_maybe id = case Var.idDetails id of PrimOpId op -> Just op _ -> Nothing isFCallId id = case Var.idDetails id of FCallId _ -> True _ -> False isFCallId_maybe id = case Var.idDetails id of FCallId call -> Just call _ -> Nothing isDataConWorkId id = case Var.idDetails id of DataConWorkId _ -> True _ -> False isDataConWorkId_maybe id = case Var.idDetails id of DataConWorkId con -> Just con _ -> Nothing isDataConId_maybe :: Id -> Maybe DataCon isDataConId_maybe id = case Var.idDetails id of DataConWorkId con -> Just con DataConWrapId con -> Just con _ -> Nothing idDataCon :: Id -> DataCon -- ^ Get from either the worker or the wrapper 'Id' to the 'DataCon'. Currently used only in the desugarer. -- -- INVARIANT: @idDataCon (dataConWrapId d) = d@: remember, 'dataConWrapId' can return either the wrapper or the worker idDataCon id = isDataConId_maybe id `orElse` pprPanic "idDataCon" (ppr id) hasNoBinding :: Id -> Bool -- ^ Returns @True@ of an 'Id' which may not have a -- binding, even though it is defined in this module. -- Data constructor workers used to be things of this kind, but -- they aren't any more. Instead, we inject a binding for -- them at the CorePrep stage. -- EXCEPT: unboxed tuples, which definitely have no binding hasNoBinding id = case Var.idDetails id of PrimOpId _ -> True -- See Note [Primop wrappers] FCallId _ -> True DataConWorkId dc -> isUnboxedTupleCon dc _ -> False isImplicitId :: Id -> Bool -- ^ 'isImplicitId' tells whether an 'Id's info is implied by other -- declarations, so we don't need to put its signature in an interface -- file, even if it's mentioned in some other interface unfolding. isImplicitId id = case Var.idDetails id of FCallId {} -> True ClassOpId {} -> True PrimOpId {} -> True DataConWorkId {} -> True DataConWrapId {} -> True -- These are are implied by their type or class decl; -- remember that all type and class decls appear in the interface file. -- The dfun id is not an implicit Id; it must *not* be omitted, because -- it carries version info for the instance decl _ -> False idIsFrom :: Module -> Id -> Bool idIsFrom mod id = nameIsLocalOrFrom mod (idName id) \end{code} Note [Primop wrappers] ~~~~~~~~~~~~~~~~~~~~~~ Currently hasNoBinding claims that PrimOpIds don't have a curried function definition. But actually they do, in GHC.PrimopWrappers, which is auto-generated from prelude/primops.txt.pp. So actually, hasNoBinding could return 'False' for PrimOpIds. But we'd need to add something in CoreToStg to swizzle any unsaturated applications of GHC.Prim.plusInt# to GHC.PrimopWrappers.plusInt#. Nota Bene: GHC.PrimopWrappers is needed *regardless*, because it's used by GHCi, which does not implement primops direct at all. \begin{code} isDeadBinder :: Id -> Bool isDeadBinder bndr | isId bndr = isDeadOcc (idOccInfo bndr) | otherwise = False -- TyVars count as not dead \end{code} %************************************************************************ %* * Evidence variables %* * %************************************************************************ \begin{code} isEvVar :: Var -> Bool isEvVar var = isPredTy (varType var) isDictId :: Id -> Bool isDictId id = isDictTy (idType id) \end{code} %************************************************************************ %* * \subsection{IdInfo stuff} %* * %************************************************************************ \begin{code} --------------------------------- -- ARITY idArity :: Id -> Arity idArity id = arityInfo (idInfo id) setIdArity :: Id -> Arity -> Id setIdArity id arity = modifyIdInfo (`setArityInfo` arity) id -- | Returns true if an application to n args would diverge isBottomingId :: Id -> Bool isBottomingId id = isBottomingSig (idStrictness id) idStrictness_maybe :: Id -> Maybe StrictSig idStrictness :: Id -> StrictSig idStrictness_maybe id = strictnessInfo (idInfo id) idStrictness id = idStrictness_maybe id `orElse` topSig setIdStrictness :: Id -> StrictSig -> Id setIdStrictness id sig = modifyIdInfo (`setStrictnessInfo` Just sig) id zapIdStrictness :: Id -> Id zapIdStrictness id = modifyIdInfo (`setStrictnessInfo` Nothing) id -- | This predicate says whether the 'Id' has a strict demand placed on it or -- has a type such that it can always be evaluated strictly (e.g., an -- unlifted type, but see the comment for 'isStrictType'). We need to -- check separately whether the 'Id' has a so-called \"strict type\" because if -- the demand for the given @id@ hasn't been computed yet but @id@ has a strict -- type, we still want @isStrictId id@ to be @True@. isStrictId :: Id -> Bool isStrictId id = ASSERT2( isId id, text "isStrictId: not an id: " <+> ppr id ) (isStrictDmd (idDemandInfo id)) || (isStrictType (idType id)) --------------------------------- -- UNFOLDING idUnfolding :: Id -> Unfolding -- Do not expose the unfolding of a loop breaker! idUnfolding id | isStrongLoopBreaker (occInfo info) = NoUnfolding | otherwise = unfoldingInfo info where info = idInfo id realIdUnfolding :: Id -> Unfolding -- Expose the unfolding if there is one, including for loop breakers realIdUnfolding id = unfoldingInfo (idInfo id) setIdUnfoldingLazily :: Id -> Unfolding -> Id setIdUnfoldingLazily id unfolding = modifyIdInfo (`setUnfoldingInfoLazily` unfolding) id setIdUnfolding :: Id -> Unfolding -> Id setIdUnfolding id unfolding = modifyIdInfo (`setUnfoldingInfo` unfolding) id idDemandInfo_maybe :: Id -> Maybe Demand idDemandInfo :: Id -> Demand idDemandInfo_maybe id = demandInfo (idInfo id) idDemandInfo id = demandInfo (idInfo id) `orElse` topDmd setIdDemandInfo :: Id -> Demand -> Id setIdDemandInfo id dmd = modifyIdInfo (`setDemandInfo` Just dmd) id --------------------------------- -- SPECIALISATION -- See Note [Specialisations and RULES in IdInfo] in IdInfo.lhs idSpecialisation :: Id -> SpecInfo idSpecialisation id = specInfo (idInfo id) idCoreRules :: Id -> [CoreRule] idCoreRules id = specInfoRules (idSpecialisation id) idHasRules :: Id -> Bool idHasRules id = not (isEmptySpecInfo (idSpecialisation id)) setIdSpecialisation :: Id -> SpecInfo -> Id setIdSpecialisation id spec_info = modifyIdInfo (`setSpecInfo` spec_info) id --------------------------------- -- CAF INFO idCafInfo :: Id -> CafInfo idCafInfo id = cafInfo (idInfo id) setIdCafInfo :: Id -> CafInfo -> Id setIdCafInfo id caf_info = modifyIdInfo (`setCafInfo` caf_info) id --------------------------------- -- Occcurrence INFO idOccInfo :: Id -> OccInfo idOccInfo id = occInfo (idInfo id) setIdOccInfo :: Id -> OccInfo -> Id setIdOccInfo id occ_info = modifyIdInfo (`setOccInfo` occ_info) id zapIdOccInfo :: Id -> Id zapIdOccInfo b = b `setIdOccInfo` NoOccInfo \end{code} --------------------------------- -- INLINING The inline pragma tells us to be very keen to inline this Id, but it's still OK not to if optimisation is switched off. \begin{code} idInlinePragma :: Id -> InlinePragma idInlinePragma id = inlinePragInfo (idInfo id) setInlinePragma :: Id -> InlinePragma -> Id setInlinePragma id prag = modifyIdInfo (`setInlinePragInfo` prag) id modifyInlinePragma :: Id -> (InlinePragma -> InlinePragma) -> Id modifyInlinePragma id fn = modifyIdInfo (\info -> info `setInlinePragInfo` (fn (inlinePragInfo info))) id idInlineActivation :: Id -> Activation idInlineActivation id = inlinePragmaActivation (idInlinePragma id) setInlineActivation :: Id -> Activation -> Id setInlineActivation id act = modifyInlinePragma id (\prag -> setInlinePragmaActivation prag act) idRuleMatchInfo :: Id -> RuleMatchInfo idRuleMatchInfo id = inlinePragmaRuleMatchInfo (idInlinePragma id) isConLikeId :: Id -> Bool isConLikeId id = isDataConWorkId id || isConLike (idRuleMatchInfo id) \end{code} --------------------------------- -- ONE-SHOT LAMBDAS \begin{code} idLBVarInfo :: Id -> LBVarInfo idLBVarInfo id = lbvarInfo (idInfo id) -- | Returns whether the lambda associated with the 'Id' is certainly applied at most once -- OR we are applying the \"state hack\" which makes it appear as if theis is the case for -- lambdas used in @IO@. You should prefer using this over 'isOneShotLambda' isOneShotBndr :: Id -> Bool -- This one is the "business end", called externally. -- Its main purpose is to encapsulate the Horrible State Hack isOneShotBndr id = isOneShotLambda id || isStateHackType (idType id) -- | Should we apply the state hack to values of this 'Type'? isStateHackType :: Type -> Bool isStateHackType ty | opt_NoStateHack = False | otherwise = case tyConAppTyCon_maybe ty of Just tycon -> tycon == statePrimTyCon _ -> False -- This is a gross hack. It claims that -- every function over realWorldStatePrimTy is a one-shot -- function. This is pretty true in practice, and makes a big -- difference. For example, consider -- a `thenST` \ r -> ...E... -- The early full laziness pass, if it doesn't know that r is one-shot -- will pull out E (let's say it doesn't mention r) to give -- let lvl = E in a `thenST` \ r -> ...lvl... -- When `thenST` gets inlined, we end up with -- let lvl = E in \s -> case a s of (r, s') -> ...lvl... -- and we don't re-inline E. -- -- It would be better to spot that r was one-shot to start with, but -- I don't want to rely on that. -- -- Another good example is in fill_in in PrelPack.lhs. We should be able to -- spot that fill_in has arity 2 (and when Keith is done, we will) but we can't yet. -- | Returns whether the lambda associated with the 'Id' is certainly applied at most once. -- You probably want to use 'isOneShotBndr' instead isOneShotLambda :: Id -> Bool isOneShotLambda id = case idLBVarInfo id of IsOneShotLambda -> True NoLBVarInfo -> False setOneShotLambda :: Id -> Id setOneShotLambda id = modifyIdInfo (`setLBVarInfo` IsOneShotLambda) id clearOneShotLambda :: Id -> Id clearOneShotLambda id | isOneShotLambda id = modifyIdInfo (`setLBVarInfo` NoLBVarInfo) id | otherwise = id -- The OneShotLambda functions simply fiddle with the IdInfo flag -- But watch out: this may change the type of something else -- f = \x -> e -- If we change the one-shot-ness of x, f's type changes \end{code} \begin{code} zapInfo :: (IdInfo -> Maybe IdInfo) -> Id -> Id zapInfo zapper id = maybeModifyIdInfo (zapper (idInfo id)) id zapLamIdInfo :: Id -> Id zapLamIdInfo = zapInfo zapLamInfo zapDemandIdInfo :: Id -> Id zapDemandIdInfo = zapInfo zapDemandInfo zapFragileIdInfo :: Id -> Id zapFragileIdInfo = zapInfo zapFragileInfo \end{code} Note [transferPolyIdInfo] ~~~~~~~~~~~~~~~~~~~~~~~~~ This transfer is used in two places: FloatOut (long-distance let-floating) SimplUtils.abstractFloats (short-distance let-floating) Consider the short-distance let-floating: f = /\a. let g = rhs in ... Then if we float thus g' = /\a. rhs f = /\a. ...[g' a/g].... we *do not* want to lose g's * strictness information * arity * inline pragma (though that is bit more debatable) * occurrence info Mostly this is just an optimisation, but it's *vital* to transfer the occurrence info. Consider NonRec { f = /\a. let Rec { g* = ..g.. } in ... } where the '*' means 'LoopBreaker'. Then if we float we must get Rec { g'* = /\a. ...(g' a)... } NonRec { f = /\a. ...[g' a/g]....} where g' is also marked as LoopBreaker. If not, terrible things can happen if we re-simplify the binding (and the Simplifier does sometimes simplify a term twice); see Trac #4345. It's not so simple to retain * worker info * rules so we simply discard those. Sooner or later this may bite us. If we abstract wrt one or more *value* binders, we must modify the arity and strictness info before transferring it. E.g. f = \x. e --> g' = \y. \x. e + substitute (g' y) for g Notice that g' has an arity one more than the original g \begin{code} transferPolyIdInfo :: Id -- Original Id -> [Var] -- Abstract wrt these variables -> Id -- New Id -> Id transferPolyIdInfo old_id abstract_wrt new_id = modifyIdInfo transfer new_id where arity_increase = count isId abstract_wrt -- Arity increases by the -- number of value binders old_info = idInfo old_id old_arity = arityInfo old_info old_inline_prag = inlinePragInfo old_info old_occ_info = occInfo old_info new_arity = old_arity + arity_increase old_strictness = strictnessInfo old_info new_strictness = fmap (increaseStrictSigArity arity_increase) old_strictness transfer new_info = new_info `setStrictnessInfo` new_strictness `setArityInfo` new_arity `setInlinePragInfo` old_inline_prag `setOccInfo` old_occ_info \end{code}