diff options
Diffstat (limited to 'compiler/rename/RnExpr.hs')
| -rw-r--r-- | compiler/rename/RnExpr.hs | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/compiler/rename/RnExpr.hs b/compiler/rename/RnExpr.hs index a0b5a1537c..475554727e 100644 --- a/compiler/rename/RnExpr.hs +++ b/compiler/rename/RnExpr.hs @@ -307,6 +307,43 @@ rnExpr e@(ELazyPat {}) = patSynErr e {- ************************************************************************ * * + Static values +* * +************************************************************************ + +For the static form we check that the free variables are all top-level +value bindings. This is done by checking that the name is external or +wired-in. See the Note about the NameSorts in Name.lhs. +-} + +rnExpr e@(HsStatic expr) = do + (expr',fvExpr) <- rnLExpr expr + stage <- getStage + case stage of + Brack _ _ -> return () -- Don't check names if we are inside brackets. + -- We don't want to reject cases like: + -- \e -> [| static $(e) |] + -- if $(e) turns out to produce a legal expression. + Splice _ -> addErr $ sep + [ text "static forms cannot be used in splices:" + , nest 2 $ ppr e + ] + _ -> do + let isTopLevelName n = isExternalName n || isWiredInName n + case nameSetElems $ filterNameSet (not . isTopLevelName) fvExpr of + [] -> return () + fvNonGlobal -> addErr $ cat + [ text $ "Only identifiers of top-level bindings can " + ++ "appear in the body of the static form:" + , nest 2 $ ppr e + , text "but the following identifiers were found instead:" + , nest 2 $ vcat $ map ppr fvNonGlobal + ] + return (HsStatic expr', fvExpr) + +{- +************************************************************************ +* * Arrow notation * * ************************************************************************ |