isUnLiftedType, typeKind, mkForAllTy, mkFunTy,
isUnboxedTupleType, isSubKind,
substTyWith, emptyTvSubst, extendTvInScope,
- TvSubst, TvSubstEnv, setTvSubstEnv, substTy,
+ TvSubst, TvSubstEnv, mkTvSubst, setTvSubstEnv, substTy,
extendTvSubst, composeTvSubst, isInScope,
getTvSubstEnv, getTvInScope )
import TyCon ( isPrimTyCon )
= do { actual_ty <- lintCoreExpr expr
; checkTys actual_ty ann_ty (mkCaseAltMsg expr actual_ty ann_ty) }
-lintCoreAlt :: Type -- Type of scrutinee; a fixed point of
- -- the substitution
- -> Type -- Type of the alternative
+lintCoreAlt :: OutType -- Type of scrutinee
+ -> OutType -- Type of the alternative
-> CoreAlt
-> LintM ()
lintCoreAlt scrut_ty alt_ty alt@(LitAlt lit, args, rhs) =
do { checkL (null args) (mkDefaultArgsMsg args)
- ; checkTys lit_ty scrut_ty
- (mkBadPatMsg lit_ty scrut_ty)
+ ; checkTys lit_ty scrut_ty (mkBadPatMsg lit_ty scrut_ty)
; checkAltExpr rhs alt_ty }
where
lit_ty = literalType lit
; con_type <- lintTyApps (dataConRepType con) tvs'
; mapM lintBinder ids -- Lint Ids in the refined world
; lintCoreArgs con_type (map Var ids)
- ; checkAltExpr rhs alt_ty
+ ; let refined_alt_ty = substTy (mkTvSubst in_scope refine) alt_ty
+ -- alt_ty is already an OutType, so don't re-apply
+ -- the current substitution. But we must apply the
+ -- refinement so that the check in checkAltExpr is ok
+ ; checkAltExpr rhs refined_alt_ty
} } }
| otherwise -- Scrut-ty is wrong shape