%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[Inst]{The @Inst@ type: dictionaries or method instances}
\begin{code}
module Inst (
- LIE, emptyLIE, unitLIE, plusLIE, consLIE, zonkLIE, plusLIEs, mkLIE,
- pprInsts, pprInstsInFull,
+ LIE, emptyLIE, unitLIE, plusLIE, consLIE, zonkLIE,
+ plusLIEs, mkLIE, isEmptyLIE,
- Inst, OverloadedLit(..), pprInst,
+ Inst, OverloadedLit(..),
+ pprInst, pprInsts, pprInstsInFull, tidyInst, tidyInsts,
InstanceMapper,
newDictFromOld, newDicts, newDictsAtLoc,
- newMethod, newMethodWithGivenTy, newOverloadedLit,
+ newMethod, newMethodWithGivenTy, newOverloadedLit, instOverloadedFun,
tyVarsOfInst, instLoc, getDictClassTys,
isDict, isTyVarDict, isStdClassTyVarDict, isMethodFor,
instBindingRequired, instCanBeGeneralised,
- zonkInst, instToId,
+ zonkInst, instToId, instToIdBndr,
InstOrigin(..), pprOrigin
) where
#include "HsVersions.h"
-import HsSyn ( HsLit(..), HsExpr(..), MonoBinds )
-import RnHsSyn ( RenamedArithSeqInfo, RenamedHsExpr )
-import TcHsSyn ( TcExpr, TcIdOcc(..), TcIdBndr,
- mkHsTyApp, mkHsDictApp, tcIdTyVars, zonkTcId
+import HsSyn ( HsLit(..), HsExpr(..) )
+import RnHsSyn ( RenamedArithSeqInfo, RenamedHsExpr, RenamedPat )
+import TcHsSyn ( TcExpr, TcId,
+ mkHsTyApp, mkHsDictApp, zonkId
)
import TcMonad
-import TcEnv ( tcLookupGlobalValueByKey, tcLookupTyConByKey )
+import TcEnv ( TcIdSet, tcLookupValueByKey, tcLookupTyConByKey )
import TcType ( TcThetaType,
- TcType, TcTauType, TcMaybe, TcTyVarSet,
- tcInstType, zonkTcType, zonkTcTypes, tcSplitForAllTy,
+ TcType, TcTauType, TcTyVarSet,
+ zonkTcType, zonkTcTypes,
zonkTcThetaType
)
-import Bag ( emptyBag, unitBag, unionBags, unionManyBags,
- listToBag, consBag, Bag )
-import Class ( classInstEnv,
- Class, ClassInstEnv
- )
-import Id ( idType, mkUserLocal, mkSysLocal, Id,
- GenIdSet, elementOfIdSet
- )
+import Bag
+import Class ( classInstEnv, Class )
+import Id ( Id, idFreeTyVars, idType, mkUserLocal, mkSysLocal )
+import VarSet ( elemVarSet )
import PrelInfo ( isStandardClass, isCcallishClass, isNoDictClass )
-import Name ( OccName(..), Name, occNameString, getOccName )
-import PprType ( TyCon, pprConstraint )
-import SpecEnv ( SpecEnv, matchSpecEnv, addToSpecEnv )
+import Name ( OccName, Name, mkDictOcc, mkMethodOcc, getOccName )
+import PprType ( pprConstraint )
+import InstEnv ( InstEnv, lookupInstEnv )
import SrcLoc ( SrcLoc )
-import Type ( Type, ThetaType, instantiateTy, instantiateThetaTy, matchTys,
- isTyVarTy, mkDictTy, splitForAllTys, splitSigmaTy,
+import Type ( Type, ThetaType,
+ mkTyVarTy, isTyVarTy, mkDictTy, splitForAllTys, splitSigmaTy,
splitRhoTy, tyVarsOfType, tyVarsOfTypes,
- mkSynTy
+ mkSynTy, tidyOpenType, tidyOpenTypes
+ )
+import InstEnv ( InstEnv )
+import Subst ( emptyInScopeSet, mkSubst,
+ substTy, substTheta, mkTyVarSubst, mkTopTyVarSubst
)
-import TyVar ( zipTyVarEnv, lookupTyVarEnv, unionTyVarSets )
-import TysPrim ( intPrimTy )
-import TysWiredIn ( intDataCon, integerTy, isIntTy, isIntegerTy, inIntRange )
+import TyCon ( TyCon )
+import Subst ( mkTyVarSubst )
+import VarEnv ( lookupVarEnv, TidyEnv,
+ lookupSubstEnv, SubstResult(..)
+ )
+import VarSet ( unionVarSet )
+import TysPrim ( intPrimTy, floatPrimTy, doublePrimTy )
+import TysWiredIn ( intDataCon, isIntTy, inIntRange,
+ floatDataCon, isFloatTy,
+ doubleDataCon, isDoubleTy,
+ integerTy, isIntegerTy
+ )
import Unique ( fromRationalClassOpKey, rationalTyConKey,
fromIntClassOpKey, fromIntegerClassOpKey, Unique
)
-import Maybes ( MaybeErr, expectJust )
-import Util ( thenCmp, zipWithEqual )
+import Maybes ( expectJust )
+import Util ( thenCmp, zipWithEqual, mapAccumL )
import Outputable
\end{code}
%************************************************************************
\begin{code}
-type LIE s = Bag (Inst s)
+type LIE = Bag Inst
+isEmptyLIE = isEmptyBag
emptyLIE = emptyBag
unitLIE inst = unitBag inst
mkLIE insts = listToBag insts
consLIE inst lie = inst `consBag` lie
plusLIEs lies = unionManyBags lies
-zonkLIE :: LIE s -> NF_TcM s (LIE s)
+zonkLIE :: LIE -> NF_TcM s LIE
zonkLIE lie = mapBagNF_Tc zonkInst lie
-pprInsts :: [Inst s] -> SDoc
-pprInsts insts = parens (hsep (punctuate comma (map pprInst insts)))
+pprInsts :: [Inst] -> SDoc
+pprInsts insts = parens (sep (punctuate comma (map pprInst insts)))
pprInstsInFull insts
Method 34 doubleId [Int] origin
\begin{code}
-data Inst s
+data Inst
= Dict
Unique
Class -- The type of the dict is (c ts), where
- [TcType s] -- c is the class and ts the types;
- (InstOrigin s)
+ [TcType] -- c is the class and ts the types;
+ InstOrigin
SrcLoc
| Method
Unique
- (TcIdOcc s) -- The overloaded function
+ TcId -- The overloaded function
-- This function will be a global, local, or ClassOpId;
-- inside instance decls (only) it can also be an InstId!
-- The id needn't be completely polymorphic.
-- You'll probably find its name (for documentation purposes)
-- inside the InstOrigin
- [TcType s] -- The types to which its polymorphic tyvars
+ [TcType] -- The types to which its polymorphic tyvars
-- should be instantiated.
-- These types must saturate the Id's foralls.
- (TcThetaType s) -- The (types of the) dictionaries to which the function
+ TcThetaType -- The (types of the) dictionaries to which the function
-- must be applied to get the method
- (TcTauType s) -- The type of the method
+ TcTauType -- The type of the method
- (InstOrigin s)
+ InstOrigin
SrcLoc
-- INVARIANT: in (Method u f tys theta tau loc)
| LitInst
Unique
OverloadedLit
- (TcType s) -- The type at which the literal is used
- (InstOrigin s) -- Always a literal; but more convenient to carry this around
+ TcType -- The type at which the literal is used
+ InstOrigin -- Always a literal; but more convenient to carry this around
SrcLoc
data OverloadedLit
maps to do their stuff.
\begin{code}
-instance Ord (Inst s) where
+instance Ord Inst where
compare = cmpInst
-instance Eq (Inst s) where
+instance Eq Inst where
(==) i1 i2 = case i1 `cmpInst` i2 of
EQ -> True
other -> False
getDictClassTys (Dict u clas tys _ _) = (clas, tys)
-tyVarsOfInst :: Inst s -> TcTyVarSet s
+tyVarsOfInst :: Inst -> TcTyVarSet
tyVarsOfInst (Dict _ _ tys _ _) = tyVarsOfTypes tys
-tyVarsOfInst (Method _ id tys _ _ _ _) = tyVarsOfTypes tys `unionTyVarSets` tcIdTyVars id
- -- The id might not be a RealId; in the case of
+tyVarsOfInst (Method _ id tys _ _ _ _) = tyVarsOfTypes tys `unionVarSet` idFreeTyVars id
+ -- The id might have free type variables; in the case of
-- locally-overloaded class methods, for example
tyVarsOfInst (LitInst _ _ ty _ _) = tyVarsOfType ty
\end{code}
Predicates
~~~~~~~~~~
\begin{code}
-isDict :: Inst s -> Bool
+isDict :: Inst -> Bool
isDict (Dict _ _ _ _ _) = True
isDict other = False
-isMethodFor :: GenIdSet (TcType s) -> Inst s -> Bool
-isMethodFor ids (Method uniq (TcId id) tys _ _ orig loc)
- = id `elementOfIdSet` ids
+isMethodFor :: TcIdSet -> Inst -> Bool
+isMethodFor ids (Method uniq id tys _ _ orig loc)
+ = id `elemVarSet` ids
isMethodFor ids inst
= False
-isTyVarDict :: Inst s -> Bool
+isTyVarDict :: Inst -> Bool
isTyVarDict (Dict _ _ tys _ _) = all isTyVarTy tys
isTyVarDict other = False
@Inst@ can be generalised over.
\begin{code}
-instBindingRequired :: Inst s -> Bool
+instBindingRequired :: Inst -> Bool
instBindingRequired (Dict _ clas _ _ _) = not (isNoDictClass clas)
instBindingRequired other = True
-instCanBeGeneralised :: Inst s -> Bool
+instCanBeGeneralised :: Inst -> Bool
instCanBeGeneralised (Dict _ clas _ _ _) = not (isCcallishClass clas)
instCanBeGeneralised other = True
\end{code}
~~~~~~~~~~~~
\begin{code}
-newDicts :: InstOrigin s
- -> TcThetaType s
- -> NF_TcM s (LIE s, [TcIdOcc s])
+newDicts :: InstOrigin
+ -> TcThetaType
+ -> NF_TcM s (LIE, [TcId])
newDicts orig theta
= tcGetSrcLoc `thenNF_Tc` \ loc ->
newDictsAtLoc orig loc theta `thenNF_Tc` \ (dicts, ids) ->
-- Local function, similar to newDicts,
-- but with slightly different interface
-newDictsAtLoc :: InstOrigin s
+newDictsAtLoc :: InstOrigin
-> SrcLoc
- -> TcThetaType s
- -> NF_TcM s ([Inst s], [TcIdOcc s])
+ -> TcThetaType
+ -> NF_TcM s ([Inst], [TcId])
newDictsAtLoc orig loc theta =
tcGetUniques (length theta) `thenNF_Tc` \ new_uniqs ->
let
in
returnNF_Tc (dicts, map instToId dicts)
-newDictFromOld :: Inst s -> Class -> [TcType s] -> NF_TcM s (Inst s)
+newDictFromOld :: Inst -> Class -> [TcType] -> NF_TcM s Inst
newDictFromOld (Dict _ _ _ orig loc) clas tys
= tcGetUnique `thenNF_Tc` \ uniq ->
returnNF_Tc (Dict uniq clas tys orig loc)
-newMethod :: InstOrigin s
- -> TcIdOcc s
- -> [TcType s]
- -> NF_TcM s (LIE s, TcIdOcc s)
+newMethod :: InstOrigin
+ -> TcId
+ -> [TcType]
+ -> NF_TcM s (LIE, TcId)
newMethod orig id tys
= -- Get the Id type and instantiate it at the specified types
- (case id of
- RealId id -> let (tyvars, rho) = splitForAllTys (idType id)
- in
- ASSERT( length tyvars == length tys)
- tcInstType (zipTyVarEnv tyvars tys) rho
-
- TcId id -> tcSplitForAllTy (idType id) `thenNF_Tc` \ (tyvars, rho) ->
- returnNF_Tc (instantiateTy (zipTyVarEnv tyvars tys) rho)
- ) `thenNF_Tc` \ rho_ty ->
let
- (theta, tau) = splitRhoTy rho_ty
+ (tyvars, rho) = splitForAllTys (idType id)
+ rho_ty = substTy (mkTyVarSubst tyvars tys) rho
+ (theta, tau) = splitRhoTy rho_ty
in
- -- Our friend does the rest
- newMethodWithGivenTy orig id tys theta tau
+ newMethodWithGivenTy orig id tys theta tau `thenNF_Tc` \ meth_inst ->
+ returnNF_Tc (unitLIE meth_inst, instToId meth_inst)
+instOverloadedFun orig (HsVar v) arg_tys theta tau
+ = newMethodWithGivenTy orig v arg_tys theta tau `thenNF_Tc` \ inst ->
+ returnNF_Tc (HsVar (instToId inst), unitLIE inst)
newMethodWithGivenTy orig id tys theta tau
= tcGetSrcLoc `thenNF_Tc` \ loc ->
let
meth_inst = Method new_uniq id tys theta tau orig loc
in
- returnNF_Tc (unitLIE meth_inst, instToId meth_inst)
+ returnNF_Tc meth_inst
-newMethodAtLoc :: InstOrigin s -> SrcLoc
- -> Id -> [TcType s]
- -> NF_TcM s (Inst s, TcIdOcc s)
+newMethodAtLoc :: InstOrigin -> SrcLoc
+ -> Id -> [TcType]
+ -> NF_TcM s (Inst, TcId)
newMethodAtLoc orig loc real_id tys -- Local function, similar to newMethod but with
-- slightly different interface
= -- Get the Id type and instantiate it at the specified types
- let
- (tyvars,rho) = splitForAllTys (idType real_id)
- in
- tcInstType (zipTyVarEnv tyvars tys) rho `thenNF_Tc` \ rho_ty ->
tcGetUnique `thenNF_Tc` \ new_uniq ->
let
- (theta, tau) = splitRhoTy rho_ty
- meth_inst = Method new_uniq (RealId real_id) tys theta tau orig loc
+ (tyvars,rho) = splitForAllTys (idType real_id)
+ rho_ty = ASSERT( length tyvars == length tys )
+ substTy (mkTopTyVarSubst tyvars tys) rho
+ (theta, tau) = splitRhoTy rho_ty
+ meth_inst = Method new_uniq real_id tys theta tau orig loc
in
returnNF_Tc (meth_inst, instToId meth_inst)
+\end{code}
-newOverloadedLit :: InstOrigin s
+In newOverloadedLit we convert directly to an Int or Integer if we
+know that's what we want. This may save some time, by not
+temporarily generating overloaded literals, but it won't catch all
+cases (the rest are caught in lookupInst).
+
+\begin{code}
+newOverloadedLit :: InstOrigin
-> OverloadedLit
- -> TcType s
- -> NF_TcM s (TcExpr s, LIE s)
+ -> TcType
+ -> NF_TcM s (TcExpr, LIE)
newOverloadedLit orig (OverloadedIntegral i) ty
| isIntTy ty && inIntRange i -- Short cut for Int
= returnNF_Tc (int_lit, emptyLIE)
where
intprim_lit = HsLitOut (HsIntPrim i) intPrimTy
integer_lit = HsLitOut (HsInt i) integerTy
- int_lit = HsApp (HsVar (RealId intDataCon)) intprim_lit
+ int_lit = HsCon intDataCon [] [intprim_lit]
newOverloadedLit orig lit ty -- The general case
= tcGetSrcLoc `thenNF_Tc` \ loc ->
\begin{code}
-instToId :: Inst s -> TcIdOcc s
-instToId (Dict u clas ty orig loc)
- = TcId (mkUserLocal occ u (mkDictTy clas ty) loc)
- where
- occ = VarOcc (SLIT("d.") _APPEND_ (occNameString (getOccName clas)))
+instToId :: Inst -> TcId
+instToId inst = instToIdBndr inst
+
+instToIdBndr :: Inst -> TcId
+instToIdBndr (Dict u clas ty orig loc)
+ = mkUserLocal (mkDictOcc (getOccName clas)) u (mkDictTy clas ty) loc
-instToId (Method u id tys theta tau orig loc)
- = TcId (mkUserLocal (getOccName id) u tau loc)
+instToIdBndr (Method u id tys theta tau orig loc)
+ = mkUserLocal (mkMethodOcc (getOccName id)) u tau loc
-instToId (LitInst u list ty orig loc)
- = TcId (mkSysLocal SLIT("lit") u ty loc)
+instToIdBndr (LitInst u list ty orig loc)
+ = mkSysLocal SLIT("lit") u ty
\end{code}
need, and it's a lot of extra work.
\begin{code}
-zonkInst :: Inst s -> NF_TcM s (Inst s)
+zonkInst :: Inst -> NF_TcM s Inst
zonkInst (Dict u clas tys orig loc)
= zonkTcTypes tys `thenNF_Tc` \ new_tys ->
returnNF_Tc (Dict u clas new_tys orig loc)
zonkInst (Method u id tys theta tau orig loc)
- = zonkTcId id `thenNF_Tc` \ new_id ->
- -- Essential to zonk the id in case it's a local variable
+ = zonkId id `thenNF_Tc` \ new_id ->
+ -- Essential to zonk the id in case it's a local variable
+ -- Can't use zonkIdOcc because the id might itself be
+ -- an InstId, in which case it won't be in scope
+
zonkTcTypes tys `thenNF_Tc` \ new_tys ->
zonkTcThetaType theta `thenNF_Tc` \ new_theta ->
zonkTcType tau `thenNF_Tc` \ new_tau ->
relevant in error messages.
\begin{code}
-instance Outputable (Inst s) where
+instance Outputable Inst where
ppr inst = pprInst inst
pprInst (LitInst u lit ty orig loc)
pprInst (Method u id tys _ _ orig loc)
= hsep [ppr id, ptext SLIT("at"),
- interppSP tys,
+ brackets (interppSP tys),
show_uniq u]
+tidyInst :: TidyEnv -> Inst -> (TidyEnv, Inst)
+tidyInst env (LitInst u lit ty orig loc)
+ = (env', LitInst u lit ty' orig loc)
+ where
+ (env', ty') = tidyOpenType env ty
+
+tidyInst env (Dict u clas tys orig loc)
+ = (env', Dict u clas tys' orig loc)
+ where
+ (env', tys') = tidyOpenTypes env tys
+
+tidyInst env (Method u id tys theta tau orig loc)
+ = (env', Method u id tys' theta tau orig loc)
+ -- Leave theta, tau alone cos we don't print them
+ where
+ (env', tys') = tidyOpenTypes env tys
+
+tidyInsts env insts = mapAccumL tidyInst env insts
+
show_uniq u = ifPprDebug (text "{-" <> ppr u <> text "-}")
\end{code}
%************************************************************************
\begin{code}
-type InstanceMapper = Class -> ClassInstEnv
+type InstanceMapper = Class -> InstEnv
\end{code}
A @ClassInstEnv@ lives inside a class, and identifies all the instances
\begin{code}
data LookupInstResult s
= NoInstance
- | SimpleInst (TcExpr s) -- Just a variable, type application, or literal
- | GenInst [Inst s] (TcExpr s) -- The expression and its needed insts
-lookupInst :: Inst s
+ | SimpleInst TcExpr -- Just a variable, type application, or literal
+ | GenInst [Inst] TcExpr -- The expression and its needed insts
+
+lookupInst :: Inst
-> NF_TcM s (LookupInstResult s)
-- Dictionaries
lookupInst dict@(Dict _ clas tys orig loc)
- = case matchSpecEnv (classInstEnv clas) tys of
+ = case lookupInstEnv (ppr clas) (classInstEnv clas) tys of
Just (tenv, dfun_id)
-> let
+ subst = mkSubst (tyVarsOfTypes tys) tenv
(tyvars, rho) = splitForAllTys (idType dfun_id)
- ty_args = map (expectJust "Inst" . lookupTyVarEnv tenv) tyvars
- -- tenv should bind all the tyvars
- in
- tcInstType tenv rho `thenNF_Tc` \ dfun_rho ->
- let
- (theta, tau) = splitRhoTy dfun_rho
- ty_app = mkHsTyApp (HsVar (RealId dfun_id)) ty_args
+ ty_args = map subst_tv tyvars
+ dfun_rho = substTy subst rho
+ (theta, tau) = splitRhoTy dfun_rho
+ ty_app = mkHsTyApp (HsVar dfun_id) ty_args
+ subst_tv tv = case lookupSubstEnv tenv tv of
+ Just (DoneTy ty) -> ty
+ -- tenv should bind all the tyvars
in
if null theta then
returnNF_Tc (SimpleInst ty_app)
= returnNF_Tc (GenInst [] integer_lit)
| in_int_range -- It's overloaded but small enough to fit into an Int
- = tcLookupGlobalValueByKey fromIntClassOpKey `thenNF_Tc` \ from_int ->
+ = tcLookupValueByKey fromIntClassOpKey `thenNF_Tc` \ from_int ->
newMethodAtLoc orig loc from_int [ty] `thenNF_Tc` \ (method_inst, method_id) ->
returnNF_Tc (GenInst [method_inst] (HsApp (HsVar method_id) int_lit))
| otherwise -- Alas, it is overloaded and a big literal!
- = tcLookupGlobalValueByKey fromIntegerClassOpKey `thenNF_Tc` \ from_integer ->
+ = tcLookupValueByKey fromIntegerClassOpKey `thenNF_Tc` \ from_integer ->
newMethodAtLoc orig loc from_integer [ty] `thenNF_Tc` \ (method_inst, method_id) ->
returnNF_Tc (GenInst [method_inst] (HsApp (HsVar method_id) integer_lit))
where
in_int_range = inIntRange i
intprim_lit = HsLitOut (HsIntPrim i) intPrimTy
integer_lit = HsLitOut (HsInt i) integerTy
- int_lit = HsApp (HsVar (RealId intDataCon)) intprim_lit
+ int_lit = HsCon intDataCon [] [intprim_lit]
+
+-- similar idea for overloaded floating point literals: if the literal is
+-- *definitely* a float or a double, generate the real thing here.
+-- This is essential (see nofib/spectral/nucleic).
lookupInst inst@(LitInst u (OverloadedFractional f) ty orig loc)
- = tcLookupGlobalValueByKey fromRationalClassOpKey `thenNF_Tc` \ from_rational ->
+ | isFloatTy ty = returnNF_Tc (GenInst [] float_lit)
+ | isDoubleTy ty = returnNF_Tc (GenInst [] double_lit)
+
+ | otherwise
+ = tcLookupValueByKey fromRationalClassOpKey `thenNF_Tc` \ from_rational ->
-- The type Rational isn't wired in so we have to conjure it up
tcLookupTyConByKey rationalTyConKey `thenNF_Tc` \ rational_tycon ->
in
newMethodAtLoc orig loc from_rational [ty] `thenNF_Tc` \ (method_inst, method_id) ->
returnNF_Tc (GenInst [method_inst] (HsApp (HsVar method_id) rational_lit))
+
+ where
+ floatprim_lit = HsLitOut (HsFloatPrim f) floatPrimTy
+ float_lit = HsCon floatDataCon [] [floatprim_lit]
+ doubleprim_lit = HsLitOut (HsDoublePrim f) doublePrimTy
+ double_lit = HsCon doubleDataCon [] [doubleprim_lit]
+
\end{code}
There is a second, simpler interface, when you want an instance of a
ambiguous dictionaries.
\begin{code}
-lookupSimpleInst :: ClassInstEnv
+lookupSimpleInst :: InstEnv
-> Class
-> [Type] -- Look up (c,t)
-> NF_TcM s (Maybe ThetaType) -- Here are the needed (c,t)s
lookupSimpleInst class_inst_env clas tys
- = case matchSpecEnv class_inst_env tys of
+ = case lookupInstEnv (ppr clas) class_inst_env tys of
Nothing -> returnNF_Tc Nothing
Just (tenv, dfun)
- -> returnNF_Tc (Just (instantiateThetaTy tenv theta))
+ -> returnNF_Tc (Just (substTheta (mkSubst emptyInScopeSet tenv) theta))
where
(_, theta, _) = splitSigmaTy (idType dfun)
\end{code}
-\begin{code}
-addClassInst
- :: ClassInstEnv -- Incoming envt
- -> [Type] -- The instance types: inst_tys
- -> Id -- Dict fun id to apply. Free tyvars of inst_ty must
- -- be the same as the forall'd tyvars of the dfun id.
- -> MaybeErr
- ClassInstEnv -- Success
- ([Type], Id) -- Offending overlap
-
-addClassInst inst_env inst_tys dfun_id = addToSpecEnv inst_env inst_tys dfun_id
-\end{code}
-
-
%************************************************************************
%* *
don't appear in the original source code. Doubtless this type will evolve...
\begin{code}
-data InstOrigin s
- = OccurrenceOf (TcIdOcc s) -- Occurrence of an overloaded identifier
+data InstOrigin
+ = OccurrenceOf TcId -- Occurrence of an overloaded identifier
| OccurrenceOfCon Id -- Occurrence of a data constructor
| RecordUpdOrigin
| LiteralOrigin HsLit -- Occurrence of a literal
+ | PatOrigin RenamedPat
+
| ArithSeqOrigin RenamedArithSeqInfo -- [x..], [x..y] etc
| SignatureOrigin -- A dict created from a type signature
\end{code}
\begin{code}
-pprOrigin :: Inst s -> SDoc
+pprOrigin :: Inst -> SDoc
pprOrigin inst
= hsep [text "arising from", pp_orig orig, text "at", ppr locn]
where
= hsep [ptext SLIT("use of"), quotes (ppr id)]
pp_orig (LiteralOrigin lit)
= hsep [ptext SLIT("the literal"), quotes (ppr lit)]
+ pp_orig (PatOrigin pat)
+ = hsep [ptext SLIT("the pattern"), quotes (ppr pat)]
pp_orig (InstanceDeclOrigin)
= ptext SLIT("an instance declaration")
pp_orig (ArithSeqOrigin seq)
projects / ghc-hetmet.git / blobdiff