tcGetGlobalTyVars,
-- Template Haskell stuff
- checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel,
+ checkWellStaged, tcMetaTy, thLevel,
topIdLvl, thTopLevelId, thRnBrack, isBrackStage,
-- New Ids
%************************************************************************
\begin{code}
-instance Outputable ThStage where
- ppr (Comp l) = text "Comp" <+> int l
- ppr (Brack l _ _) = text "Brack" <+> int l
- ppr (Splice l) = text "Splice" <+> int l
-
-
-thLevel :: ThStage -> ThLevel
-thLevel (Comp l) = l
-thLevel (Splice l) = l
-thLevel (Brack l _ _) = l
-
-
checkWellStaged :: SDoc -- What the stage check is for
-> ThLevel -- Binding level (increases inside brackets)
- -> ThStage -- Use stage
+ -> ThLevel -- Use stage
-> TcM () -- Fail if badly staged, adding an error
-checkWellStaged pp_thing bind_lvl use_stage
+checkWellStaged pp_thing bind_lvl use_lvl
| use_lvl >= bind_lvl -- OK! Used later than bound
= return () -- E.g. \x -> [| $(f x) |]
- | bind_lvl == topLevel -- GHC restriction on top level splices
+ | bind_lvl == outerLevel -- GHC restriction on top level splices
= failWithTc $
sep [ptext (sLit "GHC stage restriction:") <+> pp_thing,
- nest 2 (ptext (sLit "is used in") <+> use_lvl_doc <> ptext (sLit ", and must be imported, not defined locally"))]
+ nest 2 (vcat [ ptext (sLit "is used in a top-level splice or annotation,")
+ , ptext (sLit "and must be imported, not defined locally")])]
| otherwise -- Badly staged
= failWithTc $ -- E.g. \x -> $(f x)
ptext (sLit "Stage error:") <+> pp_thing <+>
hsep [ptext (sLit "is bound at stage") <+> ppr bind_lvl,
ptext (sLit "but used at stage") <+> ppr use_lvl]
- where
- use_lvl = thLevel use_stage
- use_lvl_doc | use_lvl == thLevel topStage = ptext (sLit "a top-level splice")
- | use_lvl == thLevel topAnnStage = ptext (sLit "an annotation")
- | otherwise = panic "checkWellStaged"
topIdLvl :: Id -> ThLevel
-- Globals may either be imported, or may be from an earlier "chunk"
-- $( f x )
-- By the time we are prcessing the $(f x), the binding for "x"
-- will be in the global env, not the local one.
-topIdLvl id | isLocalId id = topLevel
+topIdLvl id | isLocalId id = outerLevel
| otherwise = impLevel
--- Indicates the legal transitions on bracket( [| |] ).
-bracketOK :: ThStage -> Maybe ThLevel
-bracketOK (Brack _ _ _) = Nothing -- Bracket illegal inside a bracket
-bracketOK stage = Just (thLevel stage + 1)
-
--- Indicates the legal transitions on splice($).
-spliceOK :: ThStage -> Maybe ThLevel
-spliceOK (Splice _) = Nothing -- Splice illegal inside splice
-spliceOK stage = Just (thLevel stage - 1)
-
tcMetaTy :: Name -> TcM Type
-- Given the name of a Template Haskell data type,
-- return the type