import Name
import TyCon
import Type
+import TypeRep
+import Coercion
import Var
import VarSet
import TysWiredIn
tcPolyExpr expr res_ty
= addErrCtxt (exprCtxt (unLoc expr)) $
- tcPolyExprNC expr res_ty
+ (do {traceTc (text "tcPolyExpr") ; tcPolyExprNC expr res_ty })
tcPolyExprNC expr res_ty
| isSigmaTy res_ty
- = do { (gen_fn, expr') <- tcGen res_ty emptyVarSet (\_ -> tcPolyExprNC expr)
+ = do { traceTc (text "tcPolyExprNC" <+> ppr res_ty)
+ ; (gen_fn, expr') <- tcGen res_ty emptyVarSet (\_ -> tcPolyExprNC expr)
-- Note the recursive call to tcPolyExpr, because the
-- type may have multiple layers of for-alls
-- E.g. forall a. Eq a => forall b. Ord b => ....
\end{code}
-
%************************************************************************
%* *
tcExpr: the main expression typechecker
tcExpr :: HsExpr Name -> BoxyRhoType -> TcM (HsExpr TcId)
tcExpr (HsVar name) res_ty = tcId (OccurrenceOf name) name res_ty
-tcExpr (HsLit lit) res_ty = do { boxyUnify (hsLitType lit) res_ty
- ; return (HsLit lit) }
+tcExpr (HsLit lit) res_ty = do { let lit_ty = hsLitType lit
+ ; coi <- boxyUnify lit_ty res_ty
+ ; return $ wrapExprCoI (HsLit lit) coi
+ }
tcExpr (HsPar expr) res_ty = do { expr' <- tcMonoExpr expr res_ty
; return (HsPar expr') }
go lfun@(L loc fun) args
= do { (fun', args') <- -- addErrCtxt (callCtxt lfun args) $
tcApp fun (length args) (tcArgs lfun args) res_ty
+ ; traceTc (text "tcExpr args': " <+> ppr args')
; return (unLoc (foldl mkHsApp (L loc fun') args')) }
tcExpr (HsLam match) res_ty
; return (ExplicitList elt_ty exprs') }
where
tc_elt elt_ty expr = tcPolyExpr expr elt_ty
+{- TODO: Version from Tom's original patch. Unfortunately, we cannot do it this
+ way, but need to teach boxy splitters about match deferral and coercions.
+ = do { elt_tv <- newBoxyTyVar argTypeKind
+ ; let elt_ty = TyVarTy elt_tv
+ ; coi <- boxyUnify (mkTyConApp listTyCon [elt_ty]) res_ty
+ -- ; elt_ty <- boxySplitListTy res_ty
+ ; exprs' <- mappM (tc_elt elt_ty) exprs
+ ; return $ wrapExprCoI (ExplicitList elt_ty exprs') coi }
+ -- ; return (ExplicitList elt_ty exprs') }
+ where
+ tc_elt elt_ty expr = tcPolyExpr expr elt_ty
+ -}
tcExpr in_expr@(ExplicitPArr _ exprs) res_ty -- maybe empty
= do { [elt_ty] <- boxySplitTyConApp parrTyCon res_ty
-- tcFun work nicely for OpApp and Sections too
; fun' <- instFun orig fun res_subst tv_theta_prs
; co_fn' <- wrapFunResCoercion (substTys res_subst fun_arg_tys) co_fn
+ ; traceTc (text "tcIdApp: " <+> ppr (mkHsWrap co_fn' fun') <+> ppr tv_theta_prs <+> ppr co_fn' <+> ppr fun')
; return (mkHsWrap co_fn' fun', args') }
\end{code}
-- And pack up the results
; fun' <- instFun orig fun res_subst tv_theta_prs
+ ; traceTc (text "tcId yields" <+> ppr (mkHsWrap co_fn fun'))
; return (mkHsWrap co_fn fun') }
-- Note [Push result type in]
instFun orig fun subst tv_theta_prs
= do { let ty_theta_prs' = map subst_pr tv_theta_prs
-
+ ; traceTc (text "instFun" <+> ppr ty_theta_prs')
-- Make two ad-hoc checks
; doStupidChecks fun ty_theta_prs'
-- Now do normal instantiation
- ; go True fun ty_theta_prs' }
+ ; result <- go True fun ty_theta_prs'
+ ; traceTc (text "instFun result" <+> ppr result)
+ ; return result
+ }
where
subst_pr (tvs, theta)
= (substTyVars subst tvs, substTheta subst theta)
- go _ fun [] = return fun
+ go _ fun [] = do {traceTc (text "go _ fun [] returns" <+> ppr fun) ; return fun }
go True (HsVar fun_id) ((tys,theta) : prs)
| want_method_inst theta
- = do { meth_id <- newMethodWithGivenTy orig fun_id tys
+ = do { traceTc (text "go (HsVar fun_id) ((tys,theta) : prs) | want_method_inst theta")
+ ; meth_id <- newMethodWithGivenTy orig fun_id tys
; go False (HsVar meth_id) prs }
-- Go round with 'False' to prevent further use
-- of newMethod: see Note [Multiple instantiation]
go _ fun ((tys, theta) : prs)
= do { co_fn <- instCall orig tys theta
+ ; traceTc (text "go yields co_fn" <+> ppr co_fn)
; go False (HsWrap co_fn fun) prs }
-- See Note [No method sharing]
ATcId { tct_id = id, tct_type = ty, tct_co = mb_co, tct_level = lvl }
-> do { thLocalId orig id ty lvl
; case mb_co of
- Nothing -> return (HsVar id, ty) -- Wobbly, or no free vars
- Just co -> return (mkHsWrap co (HsVar id), ty) }
+ Unrefineable -> return (HsVar id, ty)
+ Rigid co -> return (mkHsWrap co (HsVar id), ty)
+ Wobbly -> traceTc (text "lookupFun" <+> ppr id) >> return (HsVar id, ty) -- Wobbly, or no free vars
+ WobblyInvisible -> failWithTc (ppr id_name <+> ptext SLIT(" not in scope because it has a wobbly type (solution: add a type annotation)"))
+ }
other -> failWithTc (ppr other <+> ptext SLIT("used where a value identifer was expected"))
}
= ptext SLIT("Can't splice the polymorphic local variable") <+> quotes (ppr id)
#endif
\end{code}
+
+\begin{code}
+wrapExprCoI :: HsExpr a -> CoercionI -> HsExpr a
+wrapExprCoI expr IdCo = expr
+wrapExprCoI expr (ACo co) = mkHsWrap (WpCo co) expr
+\end{code}
projects / ghc-hetmet.git / blobdiff