Commit b598d8ac authored by simonpj@microsoft.com's avatar simonpj@microsoft.com

More error message wibbles

parent 7966f851
......@@ -158,7 +158,7 @@ reportTidyWanteds ctxt unsolved
reportFlat :: ReportErrCtxt -> [PredType] -> CtOrigin -> TcM ()
reportFlat ctxt flats origin
= do { unless (null dicts) $ reportDictErrs ctxt dicts origin
; unless (null eqs) $ reportEqErrs ctxt eqs
; unless (null eqs) $ reportEqErrs ctxt eqs origin
; unless (null ips) $ reportIPErrs ctxt ips origin
; ASSERT( null others ) return () }
where
......@@ -277,12 +277,17 @@ reportIPErrs ctxt ips orig
%************************************************************************
\begin{code}
reportEqErrs :: ReportErrCtxt -> [PredType] -> TcM ()
reportEqErrs ctxt eqs
reportEqErrs :: ReportErrCtxt -> [PredType] -> CtOrigin -> TcM ()
reportEqErrs ctxt eqs orig
= mapM_ report_one eqs
where
report_one (EqPred ty1 ty2) = reportEqErr ctxt ty1 ty2
report_one pred = pprPanic "reportEqErrs" (ppr pred)
report_one (EqPred ty1 ty2)
= do { (env1, extra) <- getWantedEqExtra (cec_tidy ctxt) orig ty1 ty2
; let ctxt' = ctxt { cec_tidy = env1
, cec_extra = cec_extra ctxt $$ extra }
; reportEqErr ctxt' ty1 ty2 }
report_one pred
= pprPanic "reportEqErrs" (ppr pred)
reportEqErr :: ReportErrCtxt -> TcType -> TcType -> TcM ()
reportEqErr ctxt ty1 ty2
......@@ -652,23 +657,25 @@ kindErrorTcS :: CtFlavor -> TcType -> TcType -> TcS ()
kindErrorTcS fl ty1 ty2
= wrapErrTcS $
setCtFlavorLoc fl $
do { (env0, extra) <- getEqExtra fl ty1 ty2
; let (env1, ty1') = tidyOpenType env0 ty1
(env2, ty2') = tidyOpenType env1 ty2
do { env0 <- tcInitTidyEnv
; (env1, extra) <- getEqExtra env0 fl ty1 ty2
; let (env2, ty1') = tidyOpenType env1 ty1
(env3, ty2') = tidyOpenType env2 ty2
ctxt = CEC { cec_encl = []
, cec_extra = extra
, cec_tidy = env2 }
, cec_tidy = env3 }
; reportEqErr ctxt ty1' ty2' }
misMatchErrorTcS :: CtFlavor -> TcType -> TcType -> TcS a
misMatchErrorTcS fl ty1 ty2
= wrapErrTcS $
setCtFlavorLoc fl $
do { (env0, extra) <- getEqExtra fl ty1 ty2
do { env0 <- tcInitTidyEnv
; let (env1, ty1') = tidyOpenType env0 ty1
(env2, ty2') = tidyOpenType env1 ty2
(env3, msg) = misMatchMsgWithExtras env2 ty1' ty2'
; failWithTcM (env3, inaccessible_msg $$ msg $$ extra) }
; (env4, extra) <- getEqExtra env3 fl ty1 ty2
; failWithTcM (env4, inaccessible_msg $$ msg $$ extra) }
where
inaccessible_msg
= case fl of
......@@ -686,11 +693,12 @@ occursCheckErrorTcS :: CtFlavor -> TcTyVar -> TcType -> TcS a
occursCheckErrorTcS fl tv ty
= wrapErrTcS $
setCtFlavorLoc fl $
do { (env0, extra2) <- getEqExtra fl (mkTyVarTy tv) ty
; let (env1, tv') = tidyOpenTyVar env0 tv
do { env0 <- tcInitTidyEnv
; let (env1, tv') = tidyOpenTyVar env0 tv
(env2, ty') = tidyOpenType env1 ty
extra1 = sep [ppr tv', char '=', ppr ty']
; failWithTcM (env2, hang msg 2 (extra1 $$ extra2)) }
; (env3, extra2) <- getEqExtra env2 fl (mkTyVarTy tv) ty
; failWithTcM (env3, hang msg 2 (extra1 $$ extra2)) }
where
msg = text $ "Occurs check: cannot construct the infinite type:"
......@@ -735,21 +743,19 @@ setCtFlavorLoc (Wanted loc) thing = setCtLoc loc thing
setCtFlavorLoc (Derived loc) thing = setCtLoc loc thing
setCtFlavorLoc (Given loc) thing = setCtLoc loc thing
getEqExtra :: CtFlavor -> TcType -> TcType -> TcM (TidyEnv, SDoc)
getEqExtra (Wanted loc) ty1 ty2 = getWantedEqExtra (ctLocOrigin loc) ty1 ty2
getEqExtra (Derived loc) ty1 ty2 = getWantedEqExtra (ctLocOrigin loc) ty1 ty2
getEqExtra (Given _) _ _ = do { env0 <- tcInitTidyEnv
; return (env0, empty) }
getEqExtra :: TidyEnv -> CtFlavor -> TcType -> TcType -> TcM (TidyEnv, SDoc)
getEqExtra env (Wanted loc) ty1 ty2 = getWantedEqExtra env (ctLocOrigin loc) ty1 ty2
getEqExtra env (Derived loc) ty1 ty2 = getWantedEqExtra env (ctLocOrigin loc) ty1 ty2
getEqExtra env (Given _) _ _ = return (env, empty)
-- We could print more info, but it seems to be already coming out
getWantedEqExtra :: CtOrigin -> TcType -> TcType -> TcM (TidyEnv, SDoc)
getWantedEqExtra (TypeEqOrigin item) ty1 ty2
getWantedEqExtra :: TidyEnv -> CtOrigin -> TcType -> TcType -> TcM (TidyEnv, SDoc)
getWantedEqExtra env0 (TypeEqOrigin item) ty1 ty2
-- If the types in the error message are the same
-- as the types we are unifying (remember to zonk the latter)
-- don't add the extra expected/actual message
= do { act <- zonkTcType (uo_actual item)
; exp <- zonkTcType (uo_expected item)
; env0 <- tcInitTidyEnv
; if (act `tcEqType` ty1 && exp `tcEqType` ty2)
|| (exp `tcEqType` ty1 && act `tcEqType` ty2)
then
......@@ -759,7 +765,6 @@ getWantedEqExtra (TypeEqOrigin item) ty1 ty2
(env2, act') = tidyOpenType env1 act
; return (env2, mkExpectedActualMsg act' exp') } }
getWantedEqExtra orig _ _
= do { env0 <- tcInitTidyEnv
; return (env0, pprArising orig) }
getWantedEqExtra env0 orig _ _
= return (env0, pprArising orig)
\end{code}
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment