Commit 030ecd78 authored by Ian Lynagh's avatar Ian Lynagh
Browse files

Fix warnings in TcInstDcls

parent d3355c05
......@@ -6,13 +6,6 @@
TcInstDecls: Typechecking instance declarations
\begin{code}
{-# OPTIONS -w #-}
-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and fix
-- any warnings in the module. See
-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
-- for details
module TcInstDcls ( tcInstDecls1, tcInstDecls2 ) where
import HsSyn
......@@ -217,6 +210,7 @@ tcInstDecls1 tycl_decls inst_decls deriv_decls
isAssocFamily (Just _ ) = panic "isAssocFamily: no tycon?!?"
isAssocFamily Nothing = False
assocInClassErr :: Name -> SDoc
assocInClassErr name =
ptext (sLit "Associated type") <+> quotes (ppr name) <+>
ptext (sLit "must be inside a class instance")
......@@ -241,7 +235,7 @@ tcLocalInstDecl1 :: LInstDecl Name
-- Type-check all the stuff before the "where"
--
-- We check for respectable instance type, and context
tcLocalInstDecl1 decl@(L loc (InstDecl poly_ty binds uprags ats))
tcLocalInstDecl1 (L loc (InstDecl poly_ty binds uprags ats))
= -- Prime error recovery, set source location
recoverM (return ([], [])) $
setSrcSpan loc $
......@@ -300,7 +294,7 @@ tcLocalInstDecl1 decl@(L loc (InstDecl poly_ty binds uprags ats))
; mapM_ (checkIndexes clas inst_tys) ats
}
checkIndexes _ _ (hsAT, Nothing) =
checkIndexes _ _ (_, Nothing) =
return () -- skip, we already had an error here
checkIndexes clas inst_tys (hsAT, Just (ATyCon tycon)) =
-- !!!TODO: check that this does the Right Thing for indexed synonyms, too!
......@@ -494,7 +488,7 @@ tcInstDecl2 (InstInfo { iSpec = ispec, iBinds = NewTypeDerived })
-- inst_head_ty is a PredType
; let (cls, cls_inst_tys) = tcSplitDFunHead inst_head_ty
(class_tyvars, sc_theta, _, op_items) = classBigSig cls
(class_tyvars, sc_theta, _, _) = classBigSig cls
cls_tycon = classTyCon cls
sc_theta' = substTheta (zipOpenTvSubst class_tyvars cls_inst_tys) sc_theta
......@@ -699,6 +693,10 @@ mkMetaCoVars = mapM eqPredToCoVar
eqPredToCoVar (EqPred ty1 ty2) = newMetaCoVar ty1 ty2
eqPredToCoVar _ = panic "TcInstDcls.mkMetaCoVars"
tcMethods :: InstOrigin -> Class -> [TcTyVar] -> TcThetaType -> [TcType]
-> Inst -> [Inst] -> [(Id, DefMeth)] -> LHsBindsLR Name Name
-> [LSig Name]
-> TcM ([Id], Bag (LHsBind Id))
tcMethods origin clas inst_tyvars' dfun_theta' inst_tys'
this_dict extra_insts op_items monobinds uprags = do
-- Check that all the method bindings come from this class
......@@ -746,7 +744,7 @@ tcMethods origin clas inst_tyvars' dfun_theta' inst_tys'
let
prag_fn = mkPragFun uprags
all_insts = extra_insts ++ catMaybes meth_insts
sig_fn n = Just [] -- No scoped type variables, but every method has
sig_fn _ = Just [] -- No scoped type variables, but every method has
-- a type signature, in effect, so that we check
-- the method has the right type
tc_method_bind = tcMethodBind origin inst_tyvars' dfun_theta' this_dict
......@@ -856,29 +854,36 @@ simplified: only zeze2 is extracted and its body is simplified.
%************************************************************************
\begin{code}
instDeclCtxt1 :: LHsType Name -> SDoc
instDeclCtxt1 hs_inst_ty
= inst_decl_ctxt (case unLoc hs_inst_ty of
HsForAllTy _ _ _ (L _ (HsPredTy pred)) -> ppr pred
HsPredTy pred -> ppr pred
other -> ppr hs_inst_ty) -- Don't expect this
_ -> ppr hs_inst_ty) -- Don't expect this
instDeclCtxt2 :: Type -> SDoc
instDeclCtxt2 dfun_ty
= inst_decl_ctxt (ppr (mkClassPred cls tys))
where
(_,_,cls,tys) = tcSplitDFunTy dfun_ty
inst_decl_ctxt :: SDoc -> SDoc
inst_decl_ctxt doc = ptext (sLit "In the instance declaration for") <+> quotes doc
superClassCtxt :: SDoc
superClassCtxt = ptext (sLit "When checking the super-classes of an instance declaration")
atInstCtxt :: Name -> SDoc
atInstCtxt name = ptext (sLit "In the associated type instance for") <+>
quotes (ppr name)
mustBeVarArgErr :: Type -> SDoc
mustBeVarArgErr ty =
sep [ ptext (sLit "Arguments that do not correspond to a class parameter") <+>
ptext (sLit "must be variables")
, ptext (sLit "Instead of a variable, found") <+> ppr ty
]
wrongATArgErr :: Type -> Type -> SDoc
wrongATArgErr ty instTy =
sep [ ptext (sLit "Type indexes must match class instance head")
, ptext (sLit "Found") <+> ppr ty <+> ptext (sLit "but expected") <+>
......
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